U.S. patent application number 15/313519 was filed with the patent office on 2017-07-13 for system and process for the manufacture of hydrocarbons and upgraded coal by catalytic mild temperature pyrolysis of coal.
The applicant listed for this patent is LP AMINA LLC. Invention is credited to Jens Assmann, Rainer Bellinghausen, Hani Gadalla, William Latta, Matthew TARGETT, William Williams.
Application Number | 20170198221 15/313519 |
Document ID | / |
Family ID | 54554861 |
Filed Date | 2017-07-13 |
United States Patent
Application |
20170198221 |
Kind Code |
A1 |
TARGETT; Matthew ; et
al. |
July 13, 2017 |
SYSTEM AND PROCESS FOR THE MANUFACTURE OF HYDROCARBONS AND UPGRADED
COAL BY CATALYTIC MILD TEMPERATURE PYROLYSIS OF COAL
Abstract
A process for upgrading a solid carbonaceous material includes
heating the solid carbonaceous material in the presence of a
catalyst under partial pyrolysis conditions and obtaining an
upgraded solid carbonaceous product, a gaseous product, and a spent
catalyst.
Inventors: |
TARGETT; Matthew; (Sarasota,
FL) ; Gadalla; Hani; (Madison, WI) ; Latta;
William; (Mooresville, NC) ; Williams; William;
(Charlotte, NC) ; Assmann; Jens; (Haan, DE)
; Bellinghausen; Rainer; (Odenthal, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LP AMINA LLC |
Charlotte |
NC |
US |
|
|
Family ID: |
54554861 |
Appl. No.: |
15/313519 |
Filed: |
May 22, 2015 |
PCT Filed: |
May 22, 2015 |
PCT NO: |
PCT/US15/32252 |
371 Date: |
November 22, 2016 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
62002674 |
May 23, 2014 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10B 49/22 20130101;
C10K 1/005 20130101; C10G 2400/30 20130101; C10G 1/02 20130101;
C10B 57/06 20130101; C10K 1/04 20130101; C10B 53/04 20130101; Y02E
50/30 20130101; Y02P 30/20 20151101; Y02E 50/32 20130101; C10B
53/02 20130101; Y02E 50/10 20130101; C10G 2/30 20130101; C10G
2300/1011 20130101; C10B 49/16 20130101; Y02E 50/14 20130101 |
International
Class: |
C10B 53/04 20060101
C10B053/04; C10K 1/04 20060101 C10K001/04; C10B 53/02 20060101
C10B053/02; C10B 57/06 20060101 C10B057/06; C10B 49/22 20060101
C10B049/22; C10K 1/00 20060101 C10K001/00; C10G 1/02 20060101
C10G001/02 |
Claims
1. A process for upgrading a solid carbonaceous material,
comprising: heating the solid carbonaceous material in the presence
of a catalyst under partial pyrolysis conditions, and obtaining an
upgraded solid carbonaceous product, a gaseous product, and a spent
catalyst.
2. The process of claim 1, wherein the solid carbonaceous material
is coal and the upgraded solid carbonaceous product is an upgraded
coal product.
3. The process of claim 1, wherein a weight of fixed carbon
retained in the upgraded solid carbonaceous product is at least 50
weight percent of fixed carbon in the solid carbonaceous
material.
4. The process of claim 1, wherein a weight of ash retained in the
upgraded solid carbonaceous product is at least 60 weight percent
of ash in the solid carbonaceous material.
5. The process of claim 2, wherein a weight of ash retained in the
upgraded coal product is at least 60 weight percent of ash in the
coal.
6. The process of claim 1, wherein a weight of volatile matter
retained in the upgraded solid carbonaceous product is from about
10 to about 90 weight percent of volatile matter in the solid
carbonaceous material.
7. The process of claim 2, wherein a weight of volatile matter
retained in the upgraded coal product is from about 10 to about 90
weight percent of volatile matter in the coal.
8. The process of claim 1, further comprising pretreating the
starting solid carbonaceous material prior to heating under partial
pyrolysis conditions using at least one of a dryer, a de-asher, and
a washer.
9. The process of claim 1, further comprising obtaining an amount
of CO.sub.2 greater than about 10 weight % of the volatile matter
in the starting solid carbonaceous material.
10. The process of claim 1, further comprising separating the
gaseous product from the upgraded solid carbonaceous product.
11. The process of claim 11, further comprising condensing the
separated gaseous product into a gaseous stream and a liquid
stream.
12. The process of claim 11, further comprising compressing the
separated gaseous product resulting in a gaseous stream and a
liquid stream.
13. The process of claim 1, further comprising obtaining an amount
of a non-condensable fuel gas from about 1 to about 40 weight % of
the volatile matter in the starting solid carbonaceous
material.
14. The process of claim 2, further comprising obtaining an amount
of a non-condensable fuel gas from about 1 to about 40 weight % of
the volatile matter in the starting coal.
15. The process of claim 1, further comprising obtaining an amount
of LPG greater than from about 1 to about 40 weight % of the
volatile matter in the starting solid carbonaceous material.
16. The process of claim 2, further comprising obtaining an amount
of LPG greater than from about 1 to about 40 weight % of the
volatile matter in the starting coal.
17. The process of claim 1, further comprising obtaining an amount
of BTEX from about 0.5 to about 40 weight % of the volatile matter
in the starting solid carbonaceous material.
18. The process of claim 2, further comprising obtaining an amount
of BTEX from about 0.5 to about 40 weight % of the volatile matter
in the starting coal.
19. The process of claim 1, further comprising obtaining an amount
of Higher Hydrocarbons from about 0.3 to about 20 weight % of the
volatile matter in the starting solid carbonaceous material.
20. The process of claim 2, further comprising obtaining an amount
of Higher Hydrocarbons from about 0.3 to about 20 weight % of the
volatile matter in the starting coal.
21. The process of claim 1, further comprising obtaining an amount
of heteroatom-containing organics that is no greater than 5 weight
% of the volatile matter in the starting solid carbonaceous
material.
22. The process of claim 2, further comprising obtaining an amount
of heteroatom-containing organics that is no greater than 5 weight
% of the volatile matter in the starting coal.
23. The process of claim 1, wherein the spent catalyst and the
upgraded solid carbonaceous product are recovered as a mixture.
24. The process of claim 2, wherein the spent catalyst and the
upgraded solid coal are recovered as a mixture.
25. The process of claim 1, wherein the spent catalyst and the
upgraded solid carbonaceous product are recovered separately.
26. The process of claim 26, further comprising regenerating the
spent catalyst by contacting the spent catalyst with a mixture of
gases containing at least one oxidizing gas to form a regenerated
catalyst.
27. The process of claim 27, wherein at least a portion of the
regenerated catalyst is heated in the presence of additional solid
carbonaceous material in a subsequent partial pyrolysis
reaction.
28. The process of claim 26, further comprising regenerating the
spent catalyst by acid washing the spent catalyst with an acidic
solution to form a regenerated catalyst.
29. The process of claim 29, wherein at least a portion of the
regenerated catalyst is heated in the presence of additional solid
carbonaceous material in a subsequent partial pyrolysis
reaction.
30. The process of claim 1, wherein a weight of total sulfur
retained in the upgraded solid carbonaceous product is no more than
80 weight percent of the total sulfur in the starting solid
carbonaceous material.
31. The process of claim 1, wherein a weight of organic sulfur
retained in the upgraded solid carbonaceous product is no more than
50 weight percent of the organic sulfur in the starting solid
carbonaceous material.
32. The process of claim 1, wherein a weight of sulfates retained
in the upgraded solid carbonaceous product is no more than 50
weight percent of sulfates in the starting solid carbonaceous
material.
33. A process for converting a solid carbonaceous material in a
beneficiation system into a upgraded solid carbonaceous product,
the process comprising: introducing the solid carbonaceous material
and a catalyst into a pyrolysis reactor to produce a gaseous
product stream and a solid product stream, wherein the solid
product stream comprises the upgraded solid carbonaceous product;
recovering the gaseous product stream from the reactor; and
recovering the solid product stream from the reactor.
34. The process of claim 34, wherein the solid carbonaceous
material is coal and the upgraded solid carbonaceous product is an
upgraded coal product.
35. The process of claim 34, wherein the catalyst is immobilized in
the pyrolysis reactor; and the process further comprises separating
the upgraded solid carbonaceous product from the catalyst inside
the pyrolysis reactor.
36. The process of claim 36, further comprising: recovering a
separated spent catalyst from the pyrolysis reactor; transferring
the spent catalyst to a regenerator; and regenerating the spent
catalyst in the regenerator, in which unpyrolyzed coal, coke, and
carbonaceous material are removed from the spent catalyst.
37. The process of claim 36, further comprising: transferring the
gaseous product stream to a separator; and at least partially
condensing the gaseous product stream in the separator producing a
refined gas stream, a hydrocarbon liquid stream, and an aqueous
liquid phase stream.
38. The process of claim 34, wherein the solid product stream
further comprises a spent catalyst, the process further comprising:
separating the solid product stream into the upgraded solid
carbonaceous product and the spent catalyst after recovering the
solid product stream from the pyrolysis reactor, wherein the
separated spent catalyst comprises the catalyst and at least one of
unpyrolyzed coal, coke, and carbonaceous material.
39. The process of claim 39, further comprising: transferring the
separated catalyst to a regenerator in which at least a portion of
the at least one of the unpyrolyzed coal, coke, and carbonaceous
material is removed from the catalyst; and transferring the gaseous
product stream to a separator in which the gaseous product stream
is at least partially condensed in the separator producing a
refined gas stream, a hydrocarbon liquid stream, and an aqueous
liquid phase stream.
40. The process of claim 40, wherein at least a portion of the at
least one of the unpyrolyzed coal, coke, and carbonaceous material
is removed from the catalyst by at least one of combustion, steam,
and a reducing gas.
41. The process of claim 39, wherein the pyrolysis reactor is
configured as one of a HERB, a fluidized bed, a moving bed, or an
entrained flow bed, and wherein the coal and the catalyst move
through the pyrolysis reactor.
42. The process of claim 39, wherein the solid product stream is
transferred outside the pyrolysis reactor to a solid-solid
separator that separates the upgraded solid carbonaceous product
and the spent catalyst.
43. The process of claim 39, wherein the solid-solid separator
includes a classifier that separates the upgraded solid
carbonaceous product from the spent catalyst based on one of
particle size, mass, or density.
44. The process of claim 44, wherein at least one of a size and a
density of the spent catalyst is different than at least one of a
size and a density of the upgraded solid carbonaceous product, and
wherein the classifier of the solid-solid separator separates the
upgraded solid carbonaceous product and the spent catalyst based on
at least one of size and density.
45. The process of claim 34, further comprising: reducing a size of
the particles of the solid carbonaceous material in a pulverizer
prior to being introduced into the pyrolysis reactor; and
pretreating the solid carbonaceous material in a pretreating device
that includes at least one of a dryer configured to dry the coal
from the pulverizer utilizing a stream of heated fluid, a washer
configured to wash the coal from the pulverizer, and a de-asher
configured to remove ash from the coal, wherein the pretreating
device is provided between the pulverizer and the pyrolysis
reactor.
46. The process of claim 46, wherein the stream of heated fluid is
hot flue gas produced by a regenerator during removal of at least a
portion of any unpyrolyzed coal, coke, and carbonaceous material
from the spent catalyst utilizing an oxygen-carrying gas.
47. The process of claim 40, wherein the separator further includes
an acid gas removal system that separates at least one of a
sulfur-carrying compound, a nitrogen-carrying compound, and carbon
dioxide from the gaseous product stream.
48. The process of claim 34, wherein the catalyst introduced into
the pyrolysis reactor includes a first portion comprising
regenerated catalyst received from a regenerator and a second
portion comprising new catalyst that has not been regenerated, and
wherein the first portion of regenerated catalyst has a higher
relative temperature than the new catalyst and the coal, such that
the regenerated catalyst is a heating medium to heat the coal
introduced into the pyrolysis reactor.
49. The process of claim 34, wherein the catalytic pyrolysis of the
solid carbonaceous material takes place at a temperature from about
350.degree. C. to about 850.degree. C.
50. The process of claim 50, wherein the solid carbonaceous
material introduced into the pyrolysis reactor has a weighted hour
space velocity from about 0.2 to about 25 kg/hr per kg of
catalyst.
51. The process of claim 50, wherein the solid carbonaceous
material has a residence time during the catalytic process from
about 0.1 second to about 1 minute.
52. The process of claim 34, wherein a weight ratio of the catalyst
to solid carbonaceous material introduced into the pyrolysis
reactor is from about 0 to about 100.
53. The process of claim 34, further comprising: providing an acid
gas removal system that is configured to capture and isolating
CO.sub.2 from at least one of the gaseous product from the
pyrolysis reactor and a gas from a regenerator configured to
regenerate spent catalyst from the pyrolysis reactor; and obtaining
an amount of CO.sub.2 greater than about 4 weight % of the dry ash
free coal.
54. The process of claim 34, further comprising obtaining an amount
of CO.sub.2 greater than about 10 weight % of the volatile matter
in the starting solid carbonaceous material.
55. The process of claim 34, further comprising obtaining an amount
of CO.sub.2 greater than about 4 weight % of the dry ash free
coal.
56. The process of claim 34, further comprising: regenerating a
spent catalyst in a regenerator configured to produce a hot flue
gas during regeneration; and transferring at least a portion of the
hot flue gas to the pyrolysis reactor to fluidize the pyrolysis
reactor.
57. The process of claim 57, wherein a gaseous fluid comprising at
least one of CO, CO.sub.2, water, hydrogen, and oxygen is
introduced into the regenerator to facilitate removal of
unpyrolyzed coal, coke, and carbonaceous material from the spent
catalyst.
58. The process of claim 58, further comprising collecting the hot
flue gas that includes CO.sub.2 for one of carbon sequestration or
enhanced oil recovery.
59. The process of claim 58, further comprising passing the hot
flue gas through a heat exchanger to produce heat that is used to
heat the solid carbonaceous material in the pyrolysis reactor.
60. The process of claim 57, wherein the regenerator uses steam in
addition to, or instead of, air to remove the coal, coke, and
carbonaceous material from the spent catalyst by at least one of
hydrolysis and steam gasification.
61. The process of claim 57, wherein the regenerator uses hydrogen
or at least one other hydrogen-containing chemical, including
hydrocarbons, to reductively remove the coal, coke, and
carbonaceous material from the spent catalyst.
62. The process of claim 34, wherein a gas is co-fed into the
pyrolysis reactor, wherein the gas comprises at least one light
hydrocarbon compound that is recovered from the gaseous product
stream.
63. The process of claim 63, wherein the at least one light
hydrocarbon compound is recycled back to the pyrolysis reactor.
64. The process of claim 63, further comprising obtaining an amount
of BTEX from about 0.5 to about 80 weight % of the volatile matter
in the starting solid carbonaceous material.
65. The process of claim 34, wherein a biomass is co-fed into the
pyrolysis reactor.
66. The process of claim 34, wherein at least one of an oil shale,
a coal derived liquid, a tar sand, and a petroleum is co-fed into
the pyrolysis reactor.
67. The process of claim 34, wherein at least one of a wet gas and
a natural gas is co-fed into the pyrolysis reactor.
68. The process of claim 34, wherein the pyrolysis reactor includes
a stationary catalyst, such that the solid carbonaceous material
moves relative to the catalyst through the reactor, to produce the
gaseous product stream and the solid product stream, the process
further comprising: transferring the gaseous product stream to a
separator to at least partially condense at least a portion of the
gas product stream into a liquid product and a gaseous product; and
wherein the solid product stream contains less than 1 weight part
catalyst per 100 parts upgraded carbonaceous product.
69. A process for converting a biomass in a beneficiation system
into an upgraded solid product, the process comprising: introducing
the biomass and a catalyst into a pyrolysis reactor to produce a
gaseous product stream and an upgraded solid product stream, the
solid product stream comprising spent catalyst and the upgraded
solid product; separating the upgraded solid product and the spent
catalyst; transferring the separated spent catalyst to a
regenerator that removes at least a portion of any unpyrolyzed
coal, coke, and other carbonaceous material from the spent
catalyst; and transferring the gaseous product stream to a
separator that produces a liquid product and a gaseous product;
wherein a weight of ash retained in the upgraded solid product is
at least 60 weight percent of ash in the biomass introduced into
the pyrolysis reactor
70. The process of claim 1, wherein an amount of phenol produced is
less than an amount of toluene produced on a weight basis.
71. The process of claim 1, wherein an amount of tars produced is
less than an amount of light oils produced on a weight basis.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. National Stage application from
International (PCT) Application No. PCT/US2015/032252, filed on May
22, 2015, which claims the benefit of and priority to U.S.
Provisional Patent Application No. 62/002,674, filed on May 23,
2014. The foregoing applications are incorporated by reference
herein in their entireties.
FIELD
[0002] The present technology relates generally to a system and
process for the conversion of solid carbonaceous materials to a set
of usable products. More specifically, the technology relates to a
system and process that utilizes a catalyst to convert the solid
carbonaceous materials into a gaseous product, a liquid product,
and/or an upgraded solid product (e.g., an upgraded solid
carbonaceous product).
BACKGROUND
[0003] Given the uneven global distribution of crude oil reserves
and finite nature of crude oil reserves in the spotlight, there is
an ever-increasing need to develop alternative production
technologies based on alternative feedstocks (e.g., coal, biomass,
etc.). In the past decades, coal to liquid (CTL) technologies have
achieved some progress. The most technically defined route for
producing hydrocarbon liquids involves gasification, generally
involving relatively high temperature steam and oxygen co-feeds to
produce syngas. Significant cleaning of the resulting syngas is
required prior to further conversion to a methanol intermediate, or
for direct synthesis, and thus, generally involves an integrated,
multistep approach, gasification-based facility, which is typically
costly to build and operate. Another route for producing
hydrocarbon liquids from coal is the so-called direct coal
liquefaction (DCL) route which involves direct liquefaction via
high pressure treatment of coal solids with pure hydrogen. Even
though the DCL process typically utilizes catalysts, the desired
hydrocarbon product selectivity out of the catalytic reactor is low
and further processing is required. In other words, the DCL process
cannot be tailored to produce specific hydrocarbon products, and in
particular, lower molecular weight hydrocarbons. Therefore, the DCL
product stream requires significant additional chemical upgrading
steps resulting in facilities which are also cost intensive to
build and operate. Another conventional route for producing
hydrocarbon liquids from coal is through mild temperature
gasification or pyrolysis. The resulting liquid product stream from
conventional pyrolysis contains relatively high concentrations of
high molecular weight tars that require considerable upgrading,
typically via catalytic hydrogenation. The overall pyrolysis
product selectivity to non-hetero-atom containing
C.sub.1.about.C.sub.12 hydrocarbon products is relatively low.
SUMMARY
[0004] In one aspect, a process for upgrading a solid carbonaceous
material is provided. The process includes heating the solid
carbonaceous material in the presence of a catalyst under partial
pyrolysis conditions, and obtaining an upgraded solid carbonaceous
product, a gaseous product, and a spent catalyst. One non-limiting
example of solid carbonaceous material is coal and, therefore, one
non-limiting example of upgraded solid carbonaceous product is an
upgraded coal product.
[0005] In another aspect, a process for converting a solid
carbonaceous material in a beneficiation system into an upgraded
solid carbonaceous product is provided. The process includes
introducing the solid carbonaceous material and a catalyst into a
pyrolysis reactor to produce a gaseous product stream and a solid
product stream, where the solid product stream includes the
upgraded solid carbonaceous product. The process further includes
recovering the gaseous product stream from the reactor, and
recovering the solid product stream from the reactor. One
non-limiting example of solid carbonaceous material is coal and,
therefore, one non-limiting example of upgraded solid carbonaceous
product is an upgraded coal product.
[0006] In another aspect, a process for converting a biomass in a
beneficiation system into an upgraded solid product is provided.
The process includes introducing the biomass and a catalyst into a
pyrolysis reactor to produce a gaseous product stream and an
upgraded solid product stream, where the solid product stream
includes spent catalyst and the upgraded solid product. The process
further includes separating the upgraded solid product and the
spent catalyst, and transferring the separated spent catalyst to a
regenerator that removes at least a portion of any unpyrolyzed
coal, coke, and other carbonaceous material from the spent
catalyst. A weight of ash retained in the upgraded solid product is
at least 60 weight percent of ash in the biomass introduced into
the pyrolysis reactor. The process further includes transferring
the gaseous product stream to a separator that produces a liquid
product and a gaseous product.
[0007] The pyrolysis reactor may operate from about 300.degree. C.
to about 1,100.degree. C. In some embodiments, this may include
from about 350.degree. C. to about 850.degree. C., or from about
400.degree. C. to about 700.degree. C. The carbonaceous material
may have a residence time of about 0.01 second to about 5 hours. In
some embodiments, the residence time is from about 0.1 second to
about 1 minute. The catalyst loading for the pyrolysis reactor may
be from about 0 (zero) to about 100 g of catalyst/g of carbonaceous
feed material. In some embodiments the catalyst loading may be from
about 0.05 g catalyst/g feed material to about 10 g catalyst/g feed
material. The heating rate of the carbonaceous material in the
reactor may be from about 0.1.degree. C./sec to about 1000.degree.
C./sec.
[0008] In at least one embodiment, the starting carbonaceous
material enters directly into the pyrolysis reactor. In other
embodiments, prior to entering the pyrolysis reactor, the
carbonaceous material may be pre-processed, such as, for example,
via a pulverizer, a dryer, and/or any other suitable pre-processer
or pre-process discussed below.
[0009] In at least one embodiment, the starting carbonaceous
material is introduced into a pyrolysis reactor with a catalyst,
which can be mixed with the carbonaceous material before entering
the reactor, or within the reactor. The solid stream exiting the
reactor includes spent catalyst and the upgraded solid product. The
solid stream is then separated into a first solid stream containing
predominantly the upgraded solid product, which may be sent for
further processing or combustion as an upgraded solids fuel, and a
second solid stream containing predominantly spent catalyst, which
may be sent to a regeneration reactor before being recycled back
into the pyrolysis reactor. For example, the particle size
distributions of upgraded carbonaceous material and the catalyst
can be intentionally different, allowing for appropriate
classification technology to separate the two solids by differences
in particle size, weight and/or density. Other technologies may be
used as an alternative or in conjunction with the classifier, which
include but are not limited to other classifier technologies,
electrostatic separation, electrodynamic separation, triboelectric
separation and/or magnetic separation. High gradient magnetic
separators, which use high magnetic gradients to attract weakly
paramagnetic, or very fine ferromagnetic, particles, may be
utilized with the systems of this application. Open gradient
magnetic separators, which segregate falling particles in a falling
stream according to their magnetic characteristics, may be utilized
with the systems described herein. Electrodynamic separators, in
which feed particles become charged from ion bombardment and are
pinned to a rotating drum, may be utilized with the systems
described herein. In such electrodynamic separators, particles with
higher conductivity tend to lose their charge faster while those
particles with less conductivity (i.e., more insulated particles)
tend to stay attached, leading to separation of the particles.
Triboelectric separators, which charge particles through friction,
then pass the particles through an electric field to be deflected
according to the sign and magnitude of their charge.
[0010] According to another embodiment, the solids (e.g., the
catalyst and carbonaceous material) may remain separated within the
pyrolysis reactor. One example is where the catalyst is immobilized
in the reactor, such as where the catalyst is immobilized by
plating on the walls of the reactor, while the carbonaceous
material enters and exits the pyrolysis reactor. In such a system,
the need for solid-solid separation of catalyst from the upgraded
solid product outside the reactor is essentially eliminated, since
the solids remain separated within the reactor.
[0011] According to another embodiment, the solids are commingled
and then separated within the reactor. One such example is where
the reactor is in the form a fluidized bed, in which the catalyst
and starting carbonaceous material are mixed (e.g., commingled)
inside (or before entering) the reactor. After the carbonaceous
material has intimately interacted with the catalyst, the mixed
solid product stream is passed through a solid-solid separator
located inside the reactor (e.g., an internal classifier) to
separate the catalyst and carbonaceous material. In such a system,
the need for solid-solid separation of catalyst from product solids
outside the reactor is essentially eliminated, since separation
occurs within the reactor.
[0012] The gaseous product stream may be transferred to one or more
separation units, such as to condense a liquid product stream and
separate the products into desired fractions. One such example of a
separation unit is an acid gas removal system, wherein
sulfur-containing chemicals and most of the carbon dioxide are
removed, each into high purity (e.g., concentrated) streams. Other
separators may be used, and other compounds may be removed, such as
hydrogen cyanide (HCN) or ammonia (NH.sub.3). The highly
concentrated stream of carbon dioxide can be captured for
sequestration or used in the plant or pipelined for use externally,
such as for enhanced oil recovery. The highly concentrated stream
of sulfur containing compounds can be processed for landfilling, to
produce useable solid sulfur, or to produce a useable
sulfur-containing compound, such as sulfuric acid.
[0013] One gaseous product stream may include one or more
non-condensable gases or chemicals, such as, for example, methane,
ethane, ethylene, carbon monoxide, carbon dioxide, and/or hydrogen.
The non-condensable stream may also be processed further to produce
syngas for production of other chemical products, such as, but not
limited to, methanol, mixed alcohols and/or Fischer Tropsch
products. This non-condensable stream may be used as fuel in the
process, such as to provide heat for the process or other unit
operations in the plant. For example, it may be beneficial to pass
a gaseous product (e.g., methane, ethylene, ethane, hydrogen, etc.)
through the pyrolyzer as a recycle gas or a second pass stream. The
recycled gaseous product may provide additional heat and/or
hydrogen (since coal is generally low in hydrogen) into the
reactor. The liquid stream can be captured as synthetic crude oil,
or separated further to extract useable hydrocarbon chemicals into
two or more chemical streams.
[0014] In addition, it may be advantageous to introduce fuel gases
into the pyrolyzer from an external source. For example, natural
gas and/or natural gas liquids (e.g., propane, propene, butane,
butene, isobutane, isobutene, etc.) may be added from external
sources. These added fuel gases would serve the dual purposes of
providing fluidization gases and increasing the yield of useful
fuels. This would be particularly beneficial if the facility (e.g.,
plant) were near so-called "stranded gas" reserves where such
components are often disposed of by flare. This mixture of natural
gas, natural gas liquids, and other condensable hydrocarbons are
often referred to as "wet gas". For purposes of this patent, "wet
gas" will be understood to be a mixture of natural gas, natural gas
liquids, and other condensable hydrocarbons.
[0015] Such co-production may advantageously provide synergistic
benefits. The presence of free radicals in the coal and higher
hydrocarbons in the process will catalyze the pyrolysis of these
fuel gases effectively carrying out a gas-to-liquids conversion in
parallel with the coal beneficiation. This is of particular benefit
to methane pyrolysis, which is extremely difficult to carry out
without the presence of free radicals. Free radicals increase the
per-pass pyrolysis conversion of methane to higher fuels from
<1% to about 10%.
[0016] Another embodiment relates to a system and a process for
converting a carbonaceous material into multiple usable products
utilizing a catalyst. The carbonaceous material may include a coal
(e.g., a low-grade coal), a biomass, a waste, bitumen, or a
combination of any two or more carbonaceous materials. The
carbonaceous raw material may be pre-processed prior to entering
the pyrolysis reactor, such as by pulverization to resize (e.g.,
grind, reduce, etc.) the particles of raw, carbonaceous material
and/or drying to reduce the moisture content in the raw,
carbonaceous material.
[0017] The pyrolysis reactor may be configured as a moving bed, an
entrained flow bed, a fluidized bed, or any suitable reactor where
all solid material (e.g., carbonaceous material, catalyst, etc.)
moves through the reactor. Alternatively, the pyrolysis reactor may
be configured as a fixed bed or any suitable system where the
catalyst remains stationary during the reaction with the
carbonaceous material that enters and exits the reactor.
[0018] The solid material exiting the pyrolysis reactor, including
the upgraded solid product and the spent catalyst, are separated
into at least two solid streams (i.e. a solid-solid separation)
including a first stream of predominantly upgraded solid product
and a second stream of predominantly spent catalyst (e.g., a
catalyst stream), except for the immobilized catalyst reactor where
only a single solid stream of upgraded solid product exits the
reactor. The solid-solid separation of the solid material may be
performed partially or fully in situ within the pyrolysis reactor
and/or after exiting the reactor. In other words, the solid
material exiting the pyrolysis reactor may be separated internally
to the reactor or externally. The solid-solid separation of the
first and second streams can be performed using a classifier, or
similar technology, such as where the solids are separated based on
particle size, mass, and/or density, electrostatic separation
techniques, or magnetic separation techniques.
[0019] The catalyst stream including spent catalyst may be sent to
a regenerator (e.g., a regeneration unit) where the spent catalyst
is regenerated by combusting any residual (e.g., remaining,
left-over, etc.) carbonaceous material to produce mainly
regenerated catalyst and ash residue of the combusted carbonaceous
material. A portion of the spent catalyst may be sent back to the
reactor without being regenerated, or may be discarded. An
oxygen-carrying gas, such as air, may be introduced into the
regeneration reactor to regenerate the spent catalyst and combust
the remaining carbonaceous material in the regeneration reactor. A
gas stream exiting from the regenerator may include resultant flue
gas. Part, or all, of the flue gas exiting the regenerator may be
utilized to provide heat directly or indirectly to the pyrolysis
reactor, the dryer, and/or another element of the system. Some, or
all, of the gas exiting the regenerator may be used to transport
the regenerated catalyst to the pyrolysis reactor.
[0020] The non-solid product exiting from the pyrolysis reactor may
be separated into at least two streams (e.g., a gaseous product
stream and a liquid product stream). The liquid product stream may
be processed further through chemical upgrading, by separation
processes, or collected as synthetic crude product stream, which
can be refined into constituents (e.g., C.sub.5-C.sub.12) or
hydrocarbons, including aromatics. The gaseous product stream may
be processed further through chemical upgrading, by separation
processes into multiple useable process streams including a
non-condensable stream, or used within the plant, such as gaseous
fuel or collected as another product stream.
[0021] Some, or all, of the non-condensable gas product stream may
be burned for heating value. The heat may be used in the
pre-processing of the carbonaceous raw material, in the pyrolysis
reactor, or elsewhere in the plant.
[0022] Some, or all, of the gaseous product stream may be
introduced into an acid gas removal system, wherein the
sulfur-carrying compounds and/or nitrogen-containing compounds
(e.g., ammonia and hydrogen cyanide) and/or the carbon dioxide
are/is separated. The sulfur-carrying compounds can be further
processed and sold as useable sulfur-containing compounds, such as,
but not limited to, elemental sulfur and/or sulfuric acid. The
carbon dioxide stream can be sequestered, or used as a useable
product such as, but not limited to, the purpose of enhanced oil
recovery.
[0023] In at least one embodiment, a beneficiation system for
converting coal into an upgraded coal product is provided, and the
beneficiation system includes a pyrolysis reactor, a first
separator, a regenerator, and a second separator. The pyrolysis
reactor has an inlet that receives the coal and a catalyst. The
pyrolysis reactor produces a gaseous product stream and an upgraded
coal product stream, which comprises spent catalyst and the
upgraded coal product, from the coal and catalyst. The first
separator separates the upgraded coal product and the spent
catalyst. The regenerator has an inlet that receives the separated
spent catalyst from the first separator. The regenerator removes at
least a portion of any unpyrolyzed coal, coke, and other
carbonaceous material from the spent catalyst. The second separator
has an inlet that receives the gaseous product stream from the
pyrolysis reactor, and the second separator produces a liquid
product and a gaseous product from the gaseous product stream. A
weight of ash retained in the upgraded coal product may be at least
60 weight percent of ash in the coal introduced into the pyrolysis
reactor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a schematic diagram of an illustrative embodiment
of a system and process flow for converting a carbonaceous material
into one or more usable products.
[0025] FIG. 2 is a schematic diagram of another illustrative
embodiment of a system and process flow for converting a
carbonaceous material into one or more usable products.
[0026] FIG. 3 is a schematic diagram of another illustrative
embodiment of a system and process flow for converting a
carbonaceous material into one or more usable products.
[0027] FIG. 4 is a schematic diagram of yet another illustrative
embodiment of a system and process flow for converting a
carbonaceous material into one or more usable products.
[0028] FIG. 5 is a graph comparing the yield of various products
produced through an experimental system using a catalyst vs.
sand.
[0029] FIG. 6 is another graph comparing the yield of various
products produced through an experimental system using a catalyst
vs. sand.
[0030] FIG. 7 is yet another graph comparing the yield of various
products produced through an experimental system using a catalyst
vs. sand.
[0031] FIG. 8 is a cross-sectional view of an exemplary embodiment
of a pyrolysis reactor configured to provide solid-solid
separation.
[0032] FIG. 9 is a perspective view of a portion of the pyrolysis
reactor of FIG. 8.
[0033] FIG. 10 is another perspective view of a portion of the
pyrolysis reactor of FIG. 8.
[0034] FIG. 11 is a partial cross-sectional/perspective view of
another exemplary embodiment of a pyrolysis reactor configured to
provide solid-solid separation.
[0035] FIG. 12 is a schematic view of another exemplary embodiment
of a pyrolysis reactor configured to provide solid-solid
separation.
DETAILED DESCRIPTION
[0036] Prior to discussing the various embodiments disclosed in
this application, several terms used in this application will be
defined and discussed in detail for clarification. The term "solid
carbonaceous material" (e.g., SCM, carbonaceous material or CM) is
a material that is solid at standard temperature and pressure
(25.degree. C., 1 bar absolute pressure) that includes and/or
yields carbon and/or a hydrocarbon. Non-limiting examples of solid
carbonaceous material include coal, peat, lignite, biomass, coke,
semi-coke, petroleum coke, tars, or asphalt. The term "carbonaceous
material" refers to "solid carbonaceous material," unless stated
otherwise. The term "volatile matter," the term "moisture" (e.g.,
water), the term "fixed carbon," and the term "ash content" of
solid carbonaceous material shall mean the values that are
determined by proximate analysis as defined in ASTM 3172. The term
"upgraded solid carbonaceous product" (e.g., upgraded solid
carbonaceous material) is any material having one or more of the
following nine characteristics relative to the starting
carbonaceous material. First, a higher heating value (abbreviated
in this application as "HHV") as defined by ASTM D5865 method (as
received basis, e.g., including moisture, ash, and other
non-combustible material). Second, a higher heating value by ASTM
D5865 method (dry basis, where moisture is determined by ASTM 3172
method). Third, a higher heating value by ASTM D5865 method (dry,
ash-free basis where moisture and ash are determined by ASTM 3172
method). Fourth, a lower volatile matter by ASTM D3172 method.
Fifth, a lower overall sulfur content by ASTM D4239 method. Sixth,
a lower organic sulfur content by ASTM D2492 method. Seventh, a
lower sulfate content by ASTM D2492 method. Eighth, a lower pyritic
sulfur content by ASTM D2492 method. Ninth, a lower moisture by
ASTM D3172 method. Further, the term "upgraded" used with any
specific material (e.g., coal, biomass, etc.) shall also be defined
as provided above. It shall be understood that the term "upgraded
carbonaceous product" implies "upgraded solid carbonaceous
product," unless stated otherwise.
[0037] When referring to "retention" and other comparable terms
(e.g., retained, retaining), it is noted that the processes, as
disclosed in this application, fundamentally transform a feedstock
material including a solid carbonaceous material into a solid
carbonaceous product and, therefore, it is often more accurate to
consider how much of each component in the solid carbonaceous feed
material is retained in the solid carbonaceous product, rather than
the absolute weight fraction of the components in the solid
carbonaceous product. Accordingly, the term "retention" denotes a
portion of a given component in the solid carbonaceous feedstock
that is contained in the upgraded carbonaceous product. For
example, the retention of component X, may be discussed herein
(e.g., in a table) as kg of component X contained in upgraded
carbonaceous product divided by 100 kg of component X contained in
solid carbonaceous feed material. Thus, it may be considered as an
unconverted weight fraction. For example, if 100 kg of coal
containing 3% by weight sulfur is converted to 60 kg of upgraded
coal containing 3% weight sulfur, the retention of sulfur is 60 kg
per 100 kg of sulfur feed, because the coal feed contained 3 kg of
sulfur whereas the upgraded coal product contained 1.8 kg of
sulfur. The term "de-asher" is any device which reduces the ash
content in a solid carbonaceous material.
[0038] One objective of the pyrolysis of solid carbonaceous
materials is to form higher value fuels and organic chemicals. As
such, it is desirable to maximize the conversion of organic
components in the feed solid carbonaceous materials to the desired
end states. However, as a practical matter, nearly all naturally
occurring (e.g., biomass and fossil-based) solid carbonaceous
feedstocks contain ash--inorganic material bound into the solid
carbonaceous material. This ash is extremely stable and in most
chemical transformations of solid carbonaceous material (e.g.,
combustion, gasification, pyrolysis), as the solid carbonaceous
material is converted ash becomes liberated from the solid
carbonaceous material. For example, in a coal-fired steam
generation station, this ash can be manifested as a slag or fly-ash
co-product.
[0039] This liberated ash (e.g., "free ash") has been particularly
problematic in catalytic transformations. Catalytic materials are
often highly designed for a particular and/or controlled
selectivity and activity. This is done by designing the catalyst's
surface chemistry and morphology, including its porosity and
structure. Ash interferes with all of these critical features.
Inorganic ions in the ash can manipulate the surface chemistry of
active sites, and ash fines can clog pores and change morphology in
general. This leads to a number of adverse effects, several of
which are discussed herein. First, reduced activity due to
reduction in active and/or available surface area of the catalyst
can lead to lower productivity of the reactor and lower yields of
products. Second, poisoning can occur, requiring more frequent
regeneration of the catalyst or in even worse, irreversible
deactivation of the catalyst requiring replenishment of spent
catalyst with new catalyst, leading to excessive waste and an
uneconomical process. Third, reduced selectivity to desired
products can occur. For example, selectivity to the desired light
hydrocarbons and BTEX (defined below) is determined by the shape
and surface activity of the catalyst. Changes in pore size will
reduce the selectivity to these materials resulting in uncontrolled
thermal pyrolysis. Fourth, an increase in undesired by-products can
occur. Uncontrolled thermal pyrolysis, in the absence of a
catalyst, results in many undesired materials, such as tars and
heteroatom containing organics (such as phenol, which is toxic to
humans and it is also a poison in many downstream refining
operations).
[0040] Various tar fractions are known. For example, these include
ammoniacal liquor (boiling range of about 100.degree. C.), light
oil (boiling range from 100.degree. C. to about 170.degree. C.) and
potentially containing materials such as benzene, toluene, and
xylenes, middle oil (boiling range from 170.degree. C. to about
230.degree. C. and potentially containing lower naphthalene
fractions, heavy oil (boiling range from 230.degree. C. to about
270.degree. C. and potentially containing higher naphthalene
fractions, green oil (boiling range from 270.degree. C. to about
360.degree. C. and potentially containing anthracene fractions, and
the residual matter or "pitch" boiling at greater than 360.degree.
C.
[0041] Likewise Goodman et al. in their 1953 report entitled "Low
Temperature Carbonization Assay of Coal in a Precision Laboratory
Apparatus" used the Fischer Assay method to determine the main
pyrolysis products from various types of coal in terms of product
yield to char, tar, water, light oil and gas components. The light
oil components are described as comprising varying amounts of
benzene, toluene, xylenes and aromatic naphthas as well as small
amounts of carbon disulfide, naphthalene, unsaturated hydrocarbons
and saturated paraffin hydrocarbons. Based on the Fischer Assay
method, the tars contain higher hydrocarbon constituents than light
oil and the higher hydrocarbons are comprised mainly of hydrocarbon
molecules with carbon atoms greater than about C.sub.10, and
boiling range above about 270.degree. C. For purposes of this
application, "tars" or "tar products" will be understood to be
defined by this reference (i.e. hydrocarbons containing greater
than 10 carbon atoms, and "non-tar light oils" or "non-tar light
oil products" or simply "light oils" or "light oil products" will
be understood to mean any hydrocarbon containing 10 or less than
carbons. Typical uncatalyzed coal pyrolysis processes tend to yield
a relatively low product weight ratio of light oil products to tar
products, of much less than 1 in the range of about 0.08-0.25;
whereas the processes of this application tend to yield a
relatively high product weight ratio of light oil products to tar
products, much greater than 1 in the range of about 5-1000 or
greater. Also, a lower level of phenol (and other
heteroatom-containing organics) is produced in the processes of
this application. Without wishing to be bound by any particular
theory or explanation, it appears that the presence of an active
catalyst reduces the amount of phenol produced. For example, in
FIG. 7, we can see that phenol levels are higher when sand (with
little or no catalytic activity is used) compared to when a
catalyst is used. Even more advantageous, the toluene levels
produced increase when a catalyst is used (compared to when sand
with little or no catalytic activity is used), such that an amount
of toluene produced is greater than an amount of phenol produced on
a weight basis (i.e., an amount of phenol produced is less than an
amount of toluene produced on a weight basis). Also, in Table 2
(below) we can see that no phenol, or any other heteroatoms are
observed in either example embodiment. In summary, without wishing
to be bound by any theory or explanation, we believe that two
principle factors contribute to this superior performance: 1)
Presence of an active catalyst, and 2) sequestration (e.g.,
absorption and/or adsorption) of any tars produced in the upgraded
CM product, which is most often subsequently and harmlessly burned
as a fuel.
[0042] By our working explanation, presence of an active catalyst
is important to the superior performance of this process. It is
further believed that the processes of this application have
superior operability and selectivity to desired products compared
to previous processes, because much less ash is liberated compared
to the previous processes. The reduction in ash liberation is
believed to be in part due to intentionally limiting conversion
levels of the feed solid carbonaceous material to retain a majority
of ash in the product carbonaceous material. Thus, the catalyst is
exposed to much less "free ash" than in the previous processes. It
is a unique aspect (and somewhat counterintuitive) to intentionally
limit the conversion of the solid carbonaceous feedstock. While the
economics and productivity of converting as much of the solid
carbonaceous feedstock may be compelling, it is believed that
controlling conversion such that free ash production is minimized
has a greater benefit than maximizing conversion of solid
carbonaceous feedstock.
[0043] The term "non-condensable (fuel) gas" is any material, which
cannot be condensed by pressurization into a liquid at 40.degree.
C. (i.e., a gas possessing a critical temperature below 40.degree.
C.). Further, a non-condensable gas that liberates heat upon
reaction with air or oxygen is referred to herein as a
"non-condensable fuel gas."
[0044] The term "light condensable fuels," such as liquefiable
petroleum gases (LPGs), are gases that liberate heat upon reaction
with air or oxygen and are condensable at 40.degree. C. by
pressurization, but do not bear more than 7 carbon atoms and are
not aromatic.
[0045] The term "light hydrocarbons" is any material that is either
a non-condensable fuel gas or a light condensable fuel, as defined
herein.
[0046] The term "BTEX" denotes Benzene, toluene, ethylbenzene,
m-xylene, p-xylene, or o-xylene.
[0047] The term "heteroatom containing organics" is any organic
molecule bearing sulfur, oxygen, and/or nitrogen.
[0048] The term "higher hydrocarbons" is any hydrocarbon that is
not a light hydrocarbon or BTEX, as defined herein.
[0049] The term "weighted hour space velocity" (WHSV) denotes the
feed rate of substrate in weight per hour divided by weight of
catalyst contained in the reactor. WHSV has the units of hr-1. As
used herein, the weight hourly space velocity will be based on the
hourly feed of coal by weight on a dry basis, and the weight of
catalyst contained in the reactor. The weight of the catalyst will
be determined in one of two ways. For reactors where no catalyst is
removed or added (e.g., batch or fixed-bed reactors), the catalyst
weight will be the initial weight of catalyst charged to the
reactor. For reactors where some or all of the catalyst is
elutriated from the reactor continuously (e.g., fluid-bed, hybrid,
HERB, and riser reactors), the catalyst weight will be the steady
state weight of the catalyst in the reactor, where steady state is
defined by the input of fresh catalyst equaling the amount leaving
(weight basis). This is often referred to as the catalyst "hold-up"
and can be measured or estimated from known correlations for
fluid-bed or riser reactors.
[0050] The term "catalyst activity" denotes the weight of volatile
matter converted per catalyst weight over a given amount of time.
The catalyst activity can be calculated by multiplying the WHSV by
the fractional conversion of volatile matter in the reactor, or
equivalently the WHSV*(1-the retention of volatile matter).
[0051] The term "fresh catalyst" denotes a catalyst that has never
been exposed to reactants at reaction conditions, such as new
catalyst received from a vendor.
[0052] The term "spent catalyst" denotes any catalyst that has less
activity at the same reaction conditions (e.g., temperature,
pressure, inlet flows) than the catalyst had when it was originally
exposed to the process. This can be due to a number of reasons,
several non-limiting examples of causes of catalyst deactivation
are coking or carbonaceous material sorption or accumulation,
metals (and ash) sorption or accumulation, attrition, morphological
changes including changes in pore sizes, cation or anion
substitution, and/or chemical or compositional changes.
[0053] The term "regenerated catalyst" denotes a catalyst that had
become spent, as defined above, and was then subjected to a process
that increased its activity, as defined above, to a level greater
than it had as a spent catalyst. This may involve, for example,
reversing transformations or removing contaminants outlined above
as possible causes of reduced activity. The regenerated catalyst
may have an activity greater than or equal to the fresh catalyst,
but typically, regenerated catalyst has an activity that is between
the spent and fresh catalyst.
[0054] The term "HERB" is an acronym that stands for a Hybrid,
Elutriating, Riser-Bed. Any reactor that has two solids with
dissimilar densities or particle sizes, operated in such a way that
one of the solids is substantially elutriated from the reactor
(i.e., the majority of particles are entrained in a fluid and
carried out in a riser mode), whereas the other solid is
substantially fluidized, but not elutriated in the reactor, as in a
non-limiting example of a bubbling-bed reactor. FIGS. 9-13 are
non-limiting examples of HERB pyrolysis reactors.
[0055] The term "pyrolysis" refers to the thermochemical
decomposition of organic substances at elevated temperatures in the
absence of oxygen. In general, pyrolysis of organic substances
produces a gas (and liquid products when the gas product
temperatures are reduced), and leaves behind a solid residue richer
in carbon content, a char. Pyrolysis differs from other
high-temperature processes like combustion and hydrolysis in that
it usually does not involve reactions with oxygen, water, or any
other reagents. As used herein, pyrolysis shall be further
stipulated to exclude the on-purpose addition of high-pressure (in
excess of 4 bar) steam (typically referred to as "reforming"), and
the on-purpose addition of high-pressure (in excess of 4 bar)
hydrogen (typically referred to as "hydrotreating"), although these
techniques may be used post-pyrolysis on the pyrolysis products for
further upgrading. In addition, pyrolysis, as used herein, shall
not exclude water or hydrogen added with reagents at lower pressure
or as a part of a mixture with reagents, including but not limited
to, water added into the gaseous fluidization media, or moisture
carried into the pyrolysis reaction sorbed on the solid
carbonaceous material or catalyst.
[0056] The so-called proximate analysis of coal is an assay of the
moisture, ash, volatile matter, and fixed carbon as determined by a
series of prescribed or standard test methods. It serves as a
simple means of determining the distribution of products obtained
when a coal sample is heated under specific conditions. By
definition, the proximate analysis of coal separates the products
into four groups, which are (1) moisture; (2) volatile matter,
consisting of gases and vapors driven off during pyrolysis; (3)
fixed carbon, the nonvolatile fraction of coal; and (4) ash, the
inorganic residue remaining after combustion. The standard test
method for proximate analysis (ASTM D-3172) covers the methods of
analysis associated with the proximate analysis of coal and coke
and is, in fact, a combination of the determination of each of
three of the properties and calculation of a fourth. Moisture,
volatile matter, and ash are all determined by subjecting the coal
to prescribed temperature levels for prescribed time intervals. The
losses of weight are, by stipulation, due to loss of moisture (at
about 107.degree. C. for 1 hour) and loss of volatile matter (at
about 950.degree. C. for 7 minutes). The residue remaining after
ignition at the final temperature is called ash. Fixed carbon is
the difference of these three values summed and subtracted from
100. In low-volatile materials, such as coke and anthracite coal,
the fixed-carbon value equates approximately to the elemental
carbon content of the sample. Although these procedures were
initially developed for coal, the same ASTM methods have been
widely used for biomass and other organic substances. In this
application, any references to volatile matter, fixed carbon, ash,
and moisture on any solid carbonaceous material, both received or
synthesized, will be understood to be measured by this method.
[0057] Because the test method for volatile matter, as described
above, is designed in such a way to drive off substantially all the
volatile matter contained in the starting material, this process
could be described as a full pyrolysis; whereas partial pyrolysis
may be characterized by partial liberation of volatile matter and
achieved by adjusting pyrolysis conditions to milder conditions
(e.g., lower pyrolysis temperature <950.degree. C. and/or lower
pyrolysis time <7 minutes).
[0058] Volatile matter values of coal are important in choosing the
best match between a specific type of coal-burning equipment and
the coal to use with the equipment. Such values are valuable to
fuel engineers in setting up and maintaining proper burning rates.
As a general observation, low volatile anthracite coal will not
burn as fast as a high volatile bituminous coal and, therefore,
these two fuel types are not necessarily interchangeable on a given
boiler configuration. Thus, the amount of retained volatile matter
in a pyrolyzed coal is an important quality factor, among others,
determining it's suitability as a boiler fuel. For example, if the
product coal is over-pyrolyzed into a semi-coke or coke like
product, then this may limit its off-take option as a boiler fuel
although it may be used for metallurgical applications, such as
steelmaking.
[0059] The solid carbonaceous material may be pre-treated before
entering the catalytic pyrolyzer. Pretreatment steps may be
performed in such a way as to improve the reactivity of the
starting carbonaceous material in the catalytic pyrolyzer and/or to
improve the overall the quality of the products being produced in
the catalytic pyrolyzer. One such pretreatment example may include
comminution (e.g., pulverizing) and classification of the starting
carbonaceous material in order to enhance the starting carbonaceous
material's heat and mass transfer characteristics. Other examples
may include removal of moisture (e.g., drying) and/or removal of
ash and mineral components (e.g., washing) from the starting
carbonaceous material in order to promote high reactivity of the
pretreated carbonaceous material in the catalytic pyrolyzer (e.g.,
enhanced release and reactivity of volatile matter in the catalytic
pyrolyzer).
[0060] The term "immobilized" (e.g., "immobilization," etc.) when
referring to catalyst in a reactor, means that the catalyst is
prevented from exiting the reactor, not necessarily that the
catalyst remains stationary or fixed in place within the reactor.
Immobilization of the catalyst can be accomplished by a number of
methods including, but not limited to, the following: First, the
catalyst may be fixed in place via deposition, plating, or adhesion
to a packing, monolith, or wall of the reactor. Second, the use of
extrudates or large catalyst particles or grains of catalyst may be
employed, such that the catalyst cannot be fluidized or entrained
by the gas flow. Third, a size or mass exclusion where the catalyst
may be fluidized, but is not carried or entrained out by the
fluidization gas but the carbonaceous reactant is carried by the
fluidization gas (i.e., "elutriation") may be employed. Fourth, a
size exclusion where the catalyst is prevented from exiting the
reactor by sieve size allowing smaller sized carbonaceous reactant
to pass the sieve but not the catalyst may be employed. For the
third and fourth methods, the catalyst is not fixed in place and
can move around within the reactor, but is confined to the
reactor.
[0061] The term "predominantly" when referring to upgraded solid
product or catalyst, such as in a stream of predominantly upgraded
solid product/catalyst, means more than 50%. Thus, a stream of
predominantly upgraded coal product includes more than 50% upgraded
coal product.
[0062] The abbreviation HC is used to refer to hydrocarbons to
generically define any molecule containing hydrogen and carbon
atoms. We also will often denote hydrocarbons by the number of
carbon atoms contained in the molecule by the formal C.sub.x where
x is the number of carbon atoms contained in the hydrocarbon. For
example, C.sub.1, C.sub.2, and C.sub.3 will be understood to mean
any hydrocarbon containing 1, 2, or 3 carbons, respectively.
[0063] The term "separating" when referring to the separation of
solids, liquids, gases, or any combination thereof does not
necessarily mean 100% separation occurs. Even when pure separation
may be desirable, it should be understood that 100% separation is
generally not obtainable, so the term "separation" means as close
to 100% separation as is practicable.
[0064] Referring generally to the Figures, disclosed are systems
and processes for an integrated thermal pyrolysis and catalytic
conversion of coal to obtain a beneficiated coal product stream
which is substantially reduced in moisture, sulfur, mercury,
nitrogen, and oxygen content; and to obtain a hydrocarbon-rich
product stream which is substantially free of high molecular weight
tars and hetero-atom containing compounds. The process combines a
set of unit operations including a catalytic pyrolysis reactor, a
catalyst regeneration unit, and at least partial product separation
into gaseous, liquid, and solid product streams. A solid-solid
separation step is included in the process to separate upgraded
(e.g., beneficiated) coal product from the spent catalyst. The
process may also include a gaseous separator, such as, for example,
an acid gas removal (AGR) system, which removes or separates
undesirable compounds and/or elements from the gaseous product
stream. An AGR system may be utilized to remove or separate any one
or combination of, for example, carbon dioxide (CO.sub.2), which
has no heating value, hydrogen sulfide (H.sub.2S), ammonia
(NH.sub.3), hydrogen cyanide (HCN), as well as any other polluting
and/or sulfur carrying compounds. Products separated by the gaseous
separate (e.g., the AGR) may include a sulfur containing compound
stream and/or a high concentration CO.sub.2 stream, which can be
used for enhanced oil recovery, CO.sub.2 sequestration, or other
suitable purposes.
[0065] The systems and processes, as disclosed herein, may convert
carbonaceous materials, such as low-grade coals, biomass, bitumen,
solid waste, or any suitable carbon-carrying material into a set of
usable products including an upgraded carbonaceous product, as well
as gas and liquid products. A carbonaceous raw material releases
volatile matter when heated to pyrolysis temperatures. Less
suitable carbonaceous materials would include those such as coke,
which has been substantially depleted of its volatile matter
content. The catalytic pyrolysis reactor converts some or all of
the volatile matter into a gaseous product and some portion of the
volatile matter may also be converted into a solid char or coke
residue. The remaining solid material is an upgraded solid stream
with higher heating value (higher energy density) and lower
polluting elements, such as sulfur, mercury, and/or nitrogen,
compared to the starting carbonaceous material. Some light
hydrocarbon compounds (e.g., C.sub.1 to C.sub.3) may be co-fed to
the pyrolyzer and/or recovered from the hydrocarbon product stream
and recycled back to the pyrolyzer.
[0066] The systems and processes, as disclosed herein, may utilize
any combination of, for example, a pyrolysis reactor (e.g., system,
unit, etc.), a catalyst regeneration reactor (e.g., system, unit,
etc.), and/or a solid-solid separation system (e.g., unit). A
catalyst may be utilized in the systems and processes to convert
the solid carbonaceous materials into a usable gaseous product, a
usable liquid product, a usable solid product, or any combination
thereof.
[0067] The pyrolysis reactors, as disclosed herein, may utilize a
process that is a relatively mild in temperature and has a short
duration in time, thereby promoting partial catalytic pyrolysis, as
opposed to a full removal of volatile matter, of the solid
carbonaceous material. The mild temperature pyrolysis reactors may
operate from about 300.degree. C. about 1100.degree. C. In some
embodiments, the pyrolysis reactors may operate from about
350.degree. C. to about 850.degree. C. In other embodiments, the
pyrolysis reactors may operate from about 400.degree. C. to about
700.degree. C. The pyrolysis reactors utilizing mild temperature
conditions and partial pyrolysis processes provide many advantages
compared to other technologies, several of which are discussed
herein. First, the milder operating conditions (e.g., temperature)
are less energy intensive. Second, the gas product stream recovered
contains less tars. For example, an amount of light oils (e.g.,
non-tars, which may include LPGs) produced is greater than an
amount of tars produced by the processes of this application.
According to some embodiments, a ratio of the weight of light oils
produced in the processes (of this application) to the weight of
tars produced in the processes is greater than 0.3. According to
other embodiments, the ratio is greater than 1. The pyrolysis
reactors, as disclosed herein, may yield a relatively high product
weight ratio of light oil products to tar products, much greater
than 1 (e.g., 5-1000, or greater). This simplifies the product
handling and/or eliminates tar production, which is encountered in
other coal pyrolysis processes. Third, the systems may produce
three different phases of usable products, each of which can be
used for a wide variety of purposes including, but not limited to,
a fuel or a chemical precursor. For example, the systems may
produce a usable solid product (e.g., a solid stream), a usable
liquid product (e.g., a liquid stream), a usable gaseous product
(e.g., a gaseous stream), or any combination thereof. The solid
stream contains a significantly upgraded quality of solid
carbonaceous matter, which can be used as fuel or processed
further, such as for full gasification. The physical states of
matter for the fluid streams may be liquid or gaseous depending on
the temperature and pressure of the particular stream. The fluid
streams may contain a fraction of high value olefins and aromatics
that can be separated or sold in bulk as synthetic crude oil to be
processed in existing refineries. The fluid streams may also
contain a variety of chemicals that can be used as fuels within the
plant or separated for saleable fuels (e.g., hydrogen, carbon
monoxide, LPGs, natural gas liquids (NGL), etc.), as monomers,
and/or as intermediates for subsequent chemical processes. Fourth,
by running the pyrolysis reactors at mild temperature conditions
only a portion of volatile matter will be liberated from the
starting solid carbonaceous material, the remainder of which will
be retained in the upgraded solid product, such as upgraded solid
coal product so that the upgraded solid coal product is more
suitable for downstream combustion operations.
[0068] FIG. 1 illustrates an illustrative embodiment of a system
100 configured to use a solid carbonaceous material, such as, for
example low-grade coal. As shown, the system includes a pulverizer
101, a dryer 102, an assembly for performing the pyrolysis (e.g., a
pyrolysis reactor 103, a pyrolyzer, etc.), a separator (e.g., a
condenser 104, a classifier 105, a product separation unit 106,
etc.), and a regenerator 107 (e.g., regeneration assembly,
regenerator unit, regeneration reactor). The coal is introduced
into the pulverizer 101 via a pipe 111 (e.g., conveyor, tube, etc.)
for pre-processing to reduce the size of the coal into appropriate
sized particles, which are then passed into the dryer 102, such as
through a pipe 112. The pulverizer 101 may include an inlet 113
configured to introduce air (e.g., relative dry air) into the
pulverizer to help dry the coal during pulverization and an outlet
114 configured to remove relatively wet air from the pulverizer
101. In the dryer 102, the coal particles are subjected to a drying
gas (e.g., air) to reduce the moisture content in the coal
particles. The dryer 102 includes an inlet 121 for introducing
relatively dry air and an outlet 122 configured to exit the
relatively wet air from the dryer 102. The dried coal is then
passed from the dryer 102 to the pyrolysis reactor 103, such as
through an inlet pipe 123 (e.g., a first inlet) that fluidly
connects an outlet of the dryer 102 to an inlet of the pyrolysis
reactor 103.
[0069] In the pyrolysis reactor 103, the coal and the catalyst come
into contact. The catalyst may be introduced via a second inlet.
According to one non-limiting example, the reactor 103 includes a
second inlet 132 configured to introduce fresh catalyst (e.g.,
previously non-reacted catalyst) and a third inlet 133 configured
to introduce regenerated catalyst into the reactor 103. The
catalyst may be an acid catalyst, a fluid cracking catalyst, a
hydrocracking catalyst, and the like. One or more catalyst types
may be used at the same time. Such catalysts and supports for such
catalysts may include, but are not limited to metals such as Mo,
Zn, Ga, Pt, W, Ni, V, Co, Mn, or Cu; metal oxides; carbon-based
materials; and mixtures of any two or more thereof. Illustrative
examples of such catalysts and catalyst supports may include, but
are not limited to, platinum, palladium, ruthenium, osmium, nickel,
cobalt, rhenium, molybdenum, zinc, gallium, tungsten, vanadium,
manganese, copper, or a mixture or alloy of any two or more such
metals, natural zeolites, synthetic zeolites, carbon nanotubes,
graphene, graphite, alumina, and silica. The catalysts may be
microporous (pore size up to 2 nanometers) in some embodiments. In
other embodiments, the catalyst may be mesoporous (pore size from 2
to 50 nanometer) or macroporous (pore size greater than 50
nanometers). And in other embodiments the catalyst material may be
a hybrid containing any combination of micrporous, mesoporous and
macroporous structures.
[0070] Some zeolites, although not necessarily all, may be of the
formula Mx/n[(AlO.sub.2)x(SiO.sub.2)y].mH.sub.2O, where M is an
alkaline or alkaline earth metal, x and y are the total number of
tetrahedra per unit cell where the ratio of y/x is from about 1 to
about 5 for an alumina-based zeolite, or y/x is from about 10 to
about 100 for a silica zeolite. With M as an alkaline or alkaline
earth metal, n is 1 or 2. The ratio of Si/Al in the formula may
range from 12:1 to 1000:1. In some embodiments, the ratio of Si/Al
in the formula is from 14:1 to 500:1. In some embodiments, the
ratio of Si/Al in the formula is from 15:1 to 250:1. In the general
formula m is the number of water molecules of crystallization.
Other synthetic zeolites are generally known and may be used as
well. Illustrative zeolites include, but are not limited to, those
with topologies AEL, BEA, CHA, EUO, FAO, FAU, FER, KFI, LTA, LTL,
MAZ, MOR, MEL, MTW, LEV, OFF, TON, MWW, MCM and MFI. Zeolites may
also include those such as, but not limited to, ZSM-5, PSH-3,
ITQ-2, ZSM-12, MCM-22, MCM-36, MCM-49, MCM-56, MCM-58, MCM-68,
H-Beta, H--Y, H--USY, H-MOR and HZ SM-5. Illustrative unit cell
compositions of zeolites include, but are not limited to,
Na.sub.12[(AlO.sub.2).sub.12(SiO.sub.2).sub.12].27H.sub.2O;
Na.sub.6[(AlO.sub.2).sub.6(SiO.sub.2).sub.10].12H.sub.2O;
(Na,TPA).sub.3[(AlO.sub.2).sub.3(SiO.sub.2).sub.93].16H.sub.2O;
Na.sub.86[(AlO.sub.2).sub.86(SiO.sub.2).sub.106].264H.sub.2O;
Na.sub.56[(AlO.sub.2).sub.56(SiO.sub.2).sub.136].250H.sub.2O; and
Na.sub.8[(AlO.sub.2).sub.8(SiO.sub.2).sub.40].24H.sub.2O, where TPA
is tetrapropylammonium. Other frameworks as described by the
Famework Type Code (FTC) may also be used.
[0071] Some zeolites, although not necessarily all, may be of the
formula
|M.sub.x/n(H.sub.2O).sub.y|[Al.sub.xSi.sub.(t-x)O.sub.2t]-IZA,
where the guest species are listed between the braces ("| . . . |")
and the host framework is listed between the brackets ("[ . . .
]"). M represents a charge-balancing cation, x is the number of
framework Al atoms in the unit cell, n is the cation charge, y is
the number of adsorbed water molecules, t is the total number of
framework tetrahedral atoms in the unit cell (Al+Si), and IZA is
the code for the framework type assigned by the Structure
Commission of the International Zeolite Association.
[0072] The zeolites for use in the systems and processes, as
disclosed herein, can be post-treated (e.g., by de-alumination or
by ion exchange, such as is required to convert, for example, the
sodium form to H-form (e.g., H-Beta, H--Y, H--USY, H-MOR and
HZSM-5). Such de-aluminated zeolites may, for example, help promote
ethylene oligomerization. Also, for example, the zeolite particles
may be densified (e.g., post-processed to increase the bulk density
of the particles).
[0073] The catalysts may have a wide range of pore sizes (e.g.,
average pore size). For example, the catalyst may have a pore size
from about 0.26 to about 0.74 nm. This includes catalysts with a
pore size from about 0.26 to about 0.57 nm, about 0.28 to about
0.48 nm, about 0.31 to about 0.45 nm, as well as from about 0.51 to
about 0.55 nm, about 0.53 to about 0.56 nm, and about 0.65 to about
0.70 nm. For example, an A zeolite (e.g., having an LTA structure)
may have a pore size of about 0.41 nm. Also, for example, a P
zeolite (e.g., having a GIS structure) may have a pore size of
about 0.31.times.0.45 nm. Also, for example, a ZSM-5 zeolite (e.g.,
having an MFI structure) may have a pore size of about
0.53.times.0.56 nm. Also, for example, a ZSM-5 zeolite (e.g.,
having an MFI structure) may have a pore size of about
0.53.times.0.56 nm or about 0.51.times.0.55 nm. Also, for example,
an X zeolite (e.g., having an FAU structure) may have a pore size
of about 0.74 nm. Also, for example, a Y zeolite (e.g., having an
FAU structure) may have a pore size of about 0.74 nm. Also, for
example, a Mordenite zeolite (e.g., having an MOR structure) may
have a pore size of about 0.65.times.0.70 nm or about
0.26.times.0.57 nm. The pore sizes provided in this application are
examples, and are not limiting in nature.
[0074] The pyrolysis reactors may operate from about 300.degree. C.
to about 1100.degree. C. The carbonaceous material may have a
residence time of 0.01 seconds to about 5 hours. In some
embodiments, the residence time is from about 0.1 second to about 1
minute. The catalyst loading for the pyrolysis reactor may be from
about 0.01 g catalyst/g carbonaceous feed material to about 100 g
catalyst/g carbonaceous feed material. In some embodiments, the
catalyst loading is from about 0.05 g catalyst/g fee to about 20 g
catalyst/g feed. In yet other embodiments, the catalyst loading is
from about 0.1 g catalyst/g feed to about 10 g catalyst/g feed. The
heating rate of the carbonaceous material being introduced into the
pyrolysis reactor may be from about 0.1.degree. C./second to about
1000.degree. C./second. However, it is noted that flash pyrolysis
can involve a heating rate in the reactor in excess of 1000.degree.
C./second.
[0075] Also shown in FIG. 1, the solids are passed from an outlet
of the pyrolysis reactor 103 to the classifier 105 via a pipe 134.
The pyrolysis reactor 103 may include other outlets. For example,
gas products may be removed from the pyrolysis reactor 103 by way
of a second outlet and passed through a line 135 (e.g., pipe) to,
for example, the condenser 104 for further processing (e.g.,
separation). The classifier 105 is configured to separate the
upgraded coal product, which is recovered via a first outlet 151 of
the classifier, and the spent catalyst, which is recovered via a
second outlet 171 of the classifier.
[0076] According to one illustrative embodiment, the pyrolysis
reactor is a fluidized bed where the coal and catalyst are
suspended in a gaseous phase and mixed for a desired reaction
residence time. The solids may be separated in the reactor to
produce a first solid stream containing predominantly upgraded coal
and a second solid stream containing predominantly spent catalyst.
Upgraded coal generally refers to low ranked coal (e.g.,
sub-bituminous, lignite, etc.) that has been altered (e.g.,
improved), such as by removing moisture and/or pollutants, to
increase the efficiency and/or reduce the emissions of the coal
when burned (e.g., combusted). As an example, catalytic pyrolysis
of the coal may take place at a temperature of about 350.degree. C.
to about 850.degree. C., and may have a residence time from 0.1
second to about 1 minute during the catalytic process.
[0077] The first solid stream of upgraded coal can be removed from
the reactor for further processing or use. For example, the
upgraded coal can be pelletized or briquetted for purposes of
transporting the upgraded coal elsewhere. Also, for example, the
upgraded coal can be used within the plant as a solid fuel. The
stream of solid product may have a certain amount of spent catalyst
carried over with it. The second solid stream (e.g., a used
catalyst stream), which may contain some upgraded coal, is
transferred (e.g., transported), such as through a pipe or
conveyor, to the regenerator where it is mixed with air or any
suitable oxygen-carrying gas to burn off any coke and/or residual
coal on the spent catalyst to regenerate the catalyst.
[0078] As shown in FIG. 1, the spent catalyst is separated by the
classifier 105 and sent to the regenerator 107 via a line 171
(e.g., pipe) for regeneration (e.g., rejuvenation, etc.) in the
form of a spent catalyst stream. The spent catalyst stream may come
directly from the pyrolysis reactor, such as for pyrolysis reactors
that perform solid-solid separation internally. An
oxygen-containing gas stream may be introduced into the regenerator
107, which may be used to combust all or nearly all of the
combustible matter, such as coke, coal, etc., that is carried
within the spent catalyst stream into the regenerator 107. The
regenerator 107 includes an inlet through which the gas stream
enters the regenerator. The gas inlet may be the same as or
different than the spent catalyst stream inlet. For example, gas
(e.g., air) may be introduced through a gas inlet 172. The
regenerator also includes an outlet line 174 (e.g., pipe) through
which the regenerated catalyst stream exits, such as to enter the
pyrolysis reactor. In the regenerator, air or another suitable
oxygen-carrying gas is introduced to burn at least a portion of the
coke/coal off of the spent catalyst to regenerate the spent
catalyst. The regenerator 107 may include an outlet 173 through
which regenerator exit gas, such as flue gas, exits the
regenerator. Optionally, at least a portion of the regenerator exit
gas may be used to carry the regenerated catalyst to the pyrolysis
reactor. A small purge of the regenerated catalyst may be used to
prevent the accumulation of the ash or other impurities. For
example, a purge valve 175 may be provided in-line between the
outlet line 174 and a pipe connecting a first outlet of the purge
valve 175 to the third inlet 133 of the pyrolysis reactor 103. A
second outlet 176 of the purge valve 175 is configured to pass the
purged catalyst from the system.
[0079] Once regenerated, the catalyst may be returned to the
pyrolysis reactor 103 for further catalytic pyrolysis of coal. For
example, the regenerated catalyst may be reintroduced into the
pyrolysis reactor 103 via the third inlet 133. The pyrolysis
reactor 103 may include additional or fewer inlets and/or outlets.
For example, the reactor may include first and second outlets,
where the solid stream is configured to exit the reactor through
the first outlet and the fluid stream is configured to exit the
reactor through the second outlet.
[0080] A portion of the gas exiting the regenerator may include a
portion of catalyst (e.g., fines), which may be recovered and
recombined with a portion of regenerated catalyst in the
regenerated catalyst stream or introduced directly into the
pyrolysis reactor to maintain a desired catalyst-to-coal ratio. The
catalyst-to-coal ratio may be, for example, from about 0.001 g
catalyst/g carbonaceous feed to about 100 g catalyst/g carbonaceous
feed. In some embodiments, the catalyst-to-coal ratio is from about
0.01 g catalyst/g carbonaceous feed to about 100 g catalyst/g
carbonaceous feed. In other embodiments, the catalyst-to-coal ratio
is from about 0.05 g catalyst/g carbonaceous feed to about 20 g
catalyst/g carbonaceous feed. In yet other embodiments, the
catalyst-to-coal ratio is from about 0.1 g catalyst/g carbonaceous
feed to about 10 g catalyst/g carbonaceous feed. Other reactive or
nonreactive solids may be included in the catalyst regeneration
cycle as a heat source. For example, sand can be recirculated with
the catalyst, where the sand absorbs excess heat in the
regenerator. The hot sand is carried into the pyrolysis reactor
where its heat is absorbed by the incoming carbonaceous solid
material.
[0081] The fluid product stream out of the pyrolysis reactor may be
transferred downstream for further processing. For example, the
fluid product stream may be transferred to a set of unit operations
where the fluid product stream is separated into one or more liquid
hydrocarbon product streams, one or more gaseous product streams,
one or more aqueous streams, and/or a combination of any two or
more such streams. As shown in FIG. 1, the fluid product stream is
passed from the pyrolysis reactor 103 to a system (e.g., a
condenser 104) configured to act as a partial condenser affecting a
gas-liquid separation. The condenser 104 may also serve the
function of a liquid-liquid decanter allowing for separation of an
aqueous liquid phase from a hydrocarbon liquid phase due to
immiscibility. As shown, a gas stream is passed, such as through a
line 141 (e.g., an outlet pipe), from an outlet of the condenser
104 to a product separation unit 106 for further processing.
According to an exemplary embodiment, organic liquids are separated
from aqueous liquids by the condenser 104, where the organic
liquids are removed from the condenser 104 via a second outlet line
142 (e.g., pipe) and the aqueous liquids are removed from the
condenser 104 via a third outlet line 143 (e.g., pipe). Part, or
all, of each aqueous and/or hydrocarbon liquid stream may be used
downstream in, for example, other systems or processes in the plant
(e.g., facility). In one such example, at least a portion of an
aqueous liquid stream and/or a portion of a hydrocarbon stream may
be used for briquetting the coal product stream. The liquid
hydrocarbon stream may be packaged as synthetic crude oil, or
further separated into specific product streams, such as, for
example, a BTEX and/or a BTX (e.g., mixtures of aromatic
hydrocarbons such as, but not limited to, benzene, toluene, and the
three xylene isomers) rich stream. The liquid hydrocarbon stream
may also be processed further by chemical upgrading in other
chemical reactors, such as for the purpose of de-oxygenation of any
oxygen carrying products. The gaseous product stream may be used in
the plant as a fuel or separated into one or more than one useable
product stream.
[0082] As part of the separation units of the gas and liquid
products, the product stream may be processed through an acid gas
removal system to capture sulfur-carrying compounds,
nitrogen-containing compounds (e.g., ammonia or hydrogen cyanide),
and/or carbon dioxide. The carbon dioxide-rich stream can be
sequestered, sold and transported, or used for enhanced oil
recovery. As shown in FIG. 1, the CO.sub.2 stream can be separated
by the product separation unit 106 and removed via a first outlet
line 161 (e.g., pipe). The sulfur-carrying compounds may be
processed further before being packaged as a sulfur-carrying
product (e.g., as elemental solid sulfur, as sulfuric acid, etc.),
or sent to a landfill. Also shown in FIG. 1, the sulfur-carrying
compounds can be separated by the product separation unit 106 and
removed via a second outlet line 162 (e.g., pipe). The acid gas
removal system may be one of the first separation processes of the
fluid product stream exiting the pyrolysis reactor, or may be
further downstream in the separation process. Other
compounds/products may be recovered as well. For example, the
product separation unit 106 may be configured to separate
hydrocarbons, such as from the gas stream, and pass the recovered
hydrocarbons via a third outlet line 163 (e.g., pipe).
[0083] Heat from other processes in the system may be used as input
heat into the pyrolysis reactor, such as to heat the carbonaceous
material. For example, heat from the hot regenerated catalyst may
be used to provide heat and to maintain a desired temperature in
the pyrolysis reactor. Also, for example, the flue gas exiting the
catalyst regenerator may be used to provide heat either directly,
or indirectly, to the dryer and/or pyrolysis reactor. The flue gas
exiting the regeneration unit may be mixed with some of the gas
product stream and combusted to generate heat for the dryer, the
pyrolysis reactor, and/or other devices, processes, or units in the
plant. The mixing of the flue gas with some of the combustible gas
may advantageously further reduce the oxygen content in the flue
gas. The non-condensable gas stream may be combusted with plant
air, fresh air, and/or air from within the process to provide heat
to the dryer, pyrolysis reactor, regeneration reactor, and/or other
devices, processes, or units within the plant. This combusted gas
may also be used to generate steam, such as for use within the
facility.
[0084] According to one embodiment, the regeneration reactor uses a
pure oxygen stream or an oxygen rich stream to combust all or most
combustible matter on the spent catalyst or the carbonaceous matter
that is carried over into the regeneration reactor. According to
another embodiment, an oxygen lean (e.g., where the oxygen content
is diluted to less than 2%) stream is utilized with the
regenerator. According to other embodiments, hydrogen, steam,
CO.sub.2, CO, or any combination thereof is used to remove the
carbon off the spent catalyst. In yet another embodiment, oxygen is
mixed with the previously mentioned chemicals to remove the coke on
the spent catalyst. In all these embodiments, the exiting gas
stream may be rich in CO.sub.2 which can be separated for
sequestration, enhanced oil recovery, or other suitable purposes.
According to one example, at least a portion of any unpyrolyzed
coal, coke, and carbonaceous material is removed from the catalyst
by at least one of combustion, steam, and a reducing gas.
[0085] According to one embodiment, the solids of the pyrolysis
reactor are removed from the reactor and separated ex situ into a
predominantly solid stream and a predominantly spent catalyst
stream (e.g., a stream that has more than 50% catalyst). Since the
cost of the catalyst is significantly higher than the carbonaceous
material, it is desirable to keep and recycle as much catalyst as
possible. Thus, the solid-solid separation may be tailored to
minimize the amount of catalyst that is comingled with the solid
stream, even at the expense of increasing the amount of
carbonaceous material that is comingled with the spent catalyst
stream. According to an exemplary embodiment, eighty percent (80%)
by weight or more of the spent catalyst is captured during the
solid-solid separation. Preferably, ninety percent (90%) by weight
or more of the spent catalyst is captured during the solid-solid
separation.
[0086] This solid-solid separation can be performed by any number
of separation processes including, but not limited to, classifiers,
magnetic separation, electro-static separation, or a combination of
any two or more such separation processes. For example, the
particle size distributions of carbonaceous material and the
catalyst are intentionally different, allowing for appropriate
classification technology to separate the two solids by differences
in particle size, weight and/or density. In one such example, the
carbonaceous material enters the pyrolysis reactor with average
size particles from about 100 .mu.m to about 300 .mu.m. In another
such example, the carbonaceous material has average size particles
from about 10 .mu.m to about 100 .mu.m. In one example, the
catalyst enters the pyrolysis reactor with average size particles
of about 300 .mu.m to about 500 .mu.m. In another such example, the
catalyst has average size particles from about 500 .mu.m to about
1000 .mu.m. A classifier is used to effectively separate the
upgraded solid product from the catalyst. In another embodiment,
the solid stream exiting the regenerator may also be separated to
remove all or some of the ash and/or impurities before the
regenerated catalyst stream is returned to the pyrolysis reactor.
For example, the solid stream may be demineralized and/or
demetalized to remove impurities. A wet process, solid-liquid
process, or any other suitable process may be used to rejuvenate
the spent catalyst. "Fresh" catalyst as make-up catalyst could be
supplied by a vendor, whom has rejuvenated and/or demetalized spent
catalyst from other sources, such as, for example, reusing catalyst
from a pyrolysis process discussed in this application or reusing a
catalyst from a conventional fluidized catalytic cracking (FCC)
process. Stated differently, the "fresh" catalyst does not have to
consist of only "virgin" (e.g., unreacted) catalyst, but may be a
mixture of "virgin" catalyst and rejuvenated catalyst.
[0087] Some, or all, of the air streams may be used within the
system (e.g., the process of the system) or elsewhere in the
facility. For example, the air exiting the pulverizer may be used
as over-fire air in the boiler to reduce NO.sub.x (e.g., nitrous
oxides, nitric oxides, etc.) production in the furnace. Similarly,
the flue gas from the regenerator and light gas products from the
pyrolysis reactor (CO, H.sub.2, methane, ethane and ethylene) may
be used in the furnace and mixed with other chemicals for its
heating value and as a reburn stream or chemical injection for
de-NO.sub.x purposes.
[0088] In any of the above embodiments, the pyrolysis reactor may
be configured such that both catalyst and carbonaceous solid
materials enter and exit the pyrolysis reactor at controlled
rate(s) (e.g., flow rate, movement rate, etc.). In another
embodiment, the pyrolysis reactor may be configured such that the
catalyst is immobilized within the pyrolysis reactor while the
solid carbonaceous material enters and exits the reactor. In either
embodiment, a carrier gas may, or may not, be utilized to
pneumatically transport the movable solids through the reactor and
to hydrodynamically enhance mixing and chemical conversion in the
reactor. With an immobilized catalyst in the reactor, the need for
ex-situ solid-solid separation may be eliminated.
[0089] FIGS. 2 and 3 illustrate other illustrative embodiments of
systems configured to produce a usable solid stream, a usable
liquid stream, and/or a usable gaseous stream from a feedstock
(e.g., a carbonaceous feedstock, such as coal). The systems shown
in FIGS. 2 and 3 are similar to the system of FIG. 1, except each
system is configured to introduce a recycled gas (that is taken
from another process in the system) into the pyrolyzer. Thus,
common reference numerals have been used in FIGS. 1-3 to identify
common elements (e.g., components, assemblies etc.).
[0090] The system of FIG. 2 utilizes a recycled gas that has been
separated from other gases via a gas-gas separator (e.g., the
product separation unit 106, an AGR). The gas stream that is
separated from the usable liquid(s) in a gas-liquid separator
(e.g., a condenser) is then separated into two or more usable gas
streams, and at least a portion of one or more of the usable gas
streams is then routed back to the pyrolyzer as recycled gas. As
shown in FIG. 2, the gas stream from the gas-liquid separator is
separated by the product separation unit 106 into three usable gas
streams, where the first is a CO.sub.2 stream 161, the second is a
sulfur-containing gas stream 162 (e.g., H.sub.2S), and the third is
a hydrocarbon gas stream 163. At least a portion of the hydrocarbon
gas stream 163 is routed, such as through a line 265 (e.g., pipe),
to the pyrolyzer 203 to be used therein. For example, the gas-gas
separator may isolate methane, a portion of which is directed to
the pyrolyzer 203 and the remainder is recovered for use elsewhere.
The system 200 may optionally include a valve or other suitable
device that separates, for example, a usable gas stream (e.g., the
hydrocarbon gas stream) into two separate streams, such that a
portion is used as recycled gas and the other is used elsewhere.
The system 200 may optionally include a valve to purge a portion of
the recycled gas stream between the product separation unit and the
pyrolyzer. As shown in FIG. 2, a first valve 264 is configured to
control a flow of the hydrocarbon gas stream 163 through the line
265 toward the pyrolyzer 203 and a flow of the hydrocarbon gas to
be recovered for other purposes, and a second valve 266 is provided
downstream of the line 265 to control the flow of the gas stream to
be purged via a purge outlet 268 and the gas stream that is
recycled back to the pyrolyzer 203 via the recycle line 267 (e.g.,
pipe).
[0091] Also referring to FIG. 2, and according to one example, the
gas stream exiting the pyrolysis reactor 203 through a gas outlet
contains a non-condensable fuel gas. The gas stream may enter, for
example, an AGR system where all sulfur compounds and at least the
bulk of the carbon dioxide gas are removed. The sulfur compounds
can be disposed of (e.g. landfilled) or converted to a usable
product, such as solid elemental sulfur or sulfuric acid. The
CO.sub.2 stream can be further purified or transferred elsewhere
for other purposes, such as enhanced oil recovery. The cleaned gas
stream may then be further processed to recover the light molecular
weight gases (mainly methane, ethane, ethylene, hydrogen, CO) and
used to fluidize the pyrolysis reactor. One advantage of recycling
the light molecular weight gases back to in the pyrolyzer is that
these gases have a second interaction in the pyrolyzer, prompting
an increased yield of the liquid hydrocarbon fraction. Another
advantage of recycling these gases back to the pyrolyzer is that it
obviates the need for introducing another feed to the process
(e.g., nitrogen for fluidization and as carrier gas) which lowers
operating and equipment costs. The non-condensable gas fraction not
recirculated in the pyrolysis reactor can also be used in the
regeneration reactor, dryer, pyrolysis reactor, or burned in the
boiler for added heat and/or de-NO.sub.x technology. The
non-condensable gas may also be fractionated by cryogenic
distillation or other suitable means into individual components
(e.g., methane, ethane, ethylene, hydrogen, carbon monoxide) and
further processed, recycled or sold.
[0092] The system of FIG. 3 utilizes a recycled gas that has not
been separated via a gas-gas separator (e.g., a product separation
unit, an AGR). In other words, at least a portion of the gas stream
that is separated from the usable liquid(s) in a gas-liquid
separator (e.g., a condenser) is sent directly (prior to gas-gas
separation) to the pyrolyzer 303 as recycled gas. The remainder of
the gas stream may be sent downstream to fractionation units, such
as cryogenic distillation or other suitable separation devices, to
further separate the gas stream into more than one usable gas
product streams. As shown in FIG. 3, the gas stream exiting the
condenser 104 is piped via a line 341 (e.g., pipe) to a valve 364,
which controls the flow of the gas stream to the product separation
unit 106 via a line 366 (e.g., pipe) and the flow of the gas stream
to the pyrolyzer 303 via a line 365 (e.g., pipe). Thus, the valve
364 controls how much of the gas exiting the condenser 104 is
distributed as recycled gas to the pyrolyzer 303 and how much of
the gas is distributed further processing downstream by the product
separation unit 106.
[0093] Also referring to FIG. 3, according to an illustrative
embodiment, the recirculated gas comes out of the first condenser
104 prior to entering the product separation unit 106. The main
advantage of recovering the recirculation gas before the separation
units is that the separation units can be sized smaller because
they do not process the recirculating gas. The smaller size reduces
equipment size and cost, as well as reduces the energy requirement
for the separation. As with the embodiment in FIG. 2, the light
molecular weight gases entering the pyrolysis reactor promote an
increased pyrolysis yield of the liquid hydrocarbon fraction.
[0094] In yet other embodiments, the pyrolysis reaction is staged
into more than one reactor system. FIG. 4 illustrates an example of
such a staged reactor system. As shown, the system includes a first
pyrolysis assembly 403 (e.g., a first pyrolyzer, first reactor,
etc.), in which a carbonaceous feedstock material, such as coal, is
pyrolyzed to produce a gaseous pyrolysis product stream and a solid
product. The gas product stream is transferred from the first
pyrolysis assembly 403 to a second pyrolysis assembly 408 via a
first outlet pipe 435. The solid product is transferred from the
first pyrolysis assembly 403 to a classifier 105 via a second
outlet pipe 434.
[0095] As shown in FIG. 4, the pyrolysis reaction in the first
pyrolysis assembly 403 is a catalytic reaction. In the catalytic
first pyrolysis assembly, the catalyst may be fresh (i.e., new)
catalyst, regenerated catalyst (e.g., from the regenerator), or any
combination thereof. The solid product produced by the first
pyrolysis assembly 403 is delivered to a downstream solid-solid
separator (e.g., a classifier 105) via a line 434 (e.g., pipe) to
separate the spent catalyst and the upgraded solid product (e.g.,
upgraded coal). The gaseous pyrolysis product stream produced by
the first pyrolysis assembly 403 is delivered to the downstream
second pyrolysis assembly 408 (e.g., a second pyrolyzer, second
reactor, etc.) via a line 435 (e.g., pipe). Like with FIGS. 2 and
3, FIG. 4 also includes common reference numerals with numerals
used in FIGS. 1-3, which are meant to identify similar or common
elements (e.g., components, assemblies etc.). Hence, the
description of the common reference numerals is not duplicated
here.
[0096] As shown in FIG. 4, the second pyrolysis assembly 408
includes an inlet configured to receive the gaseous product stream
from the first pyrolysis assembly, such as through the inlet line
435, and therein catalytically processes the gaseous product stream
into a gaseous product and a liquid product. The second pyrolysis
assembly 408 may include additional inlets. For example, the second
pyrolysis assembly 408 may include a second inlet that is
configured to receive fresh catalyst via a line 481 (e.g., pipe)
and a third inlet that is configured to receive regenerated
catalyst via a line 482 (e.g., pipe). The second pyrolysis assembly
408 may include one or more outlets. For example, the second
pyrolysis assembly 408 may include a first outlet through which the
gas product is transferred to the condenser 104 via a line 484
(e.g., pipe) and a second outlet through which the spent catalyst
is transferred to a regenerator via a line 483 (e.g., pipe). Thus,
the spent catalyst may be delivered to a regenerator to regenerate
the spent catalyst. FIG. 4 illustrates a first catalyst regenerator
107 configured to regenerate the spent catalyst used in the first
pyrolysis assembly 403 and a second catalyst regenerator 409, which
is separate from the first catalyst regenerator 107, and is
configured to regenerate the spent catalyst used in the second
pyrolysis assembly 408. Having two separate regenerators may be
advantageous for systems in which different catalysts are used in
the two pyrolysis assemblies.
[0097] The second catalyst regenerator 409 receives the spent
catalyst via an inlet line 483 (e.g., pipe) from the second
pyrolysis assembly 408. An oxygen-containing gas stream may be
introduced into the regenerator 409 by way of inlet line 492 and
may be used to combust all or nearly all of the combustible matter
carried within the spent catalyst from the second pyrolysis
assembly 408. The regenerator 409 also includes an outlet line 494
(e.g., pipe) through which the regenerated catalyst exits the
regenerator 409. At least a portion of the regenerated catalyst may
be routed to the second pyrolysis assembly 408. The regenerator 409
may include a second outlet 491 through which regenerator exit gas,
such as flue gas, exits the regenerator. Optionally, at least a
portion of the regenerator exit gas may be used to carry the
regenerated catalyst to the pyrolysis reactor. A small purge of the
regenerated catalyst may be used to prevent the accumulation of the
ash or other impurities. For example, a purge valve 495 may be
provided in-line of the outlet line 494 to pass the purged catalyst
from the system via line 496. Line 482 may be configured to
introduce regenerated catalyst back to the second pyrolysis
assembly 408. Line 482 may be downstream from the purge valve
495.
[0098] Although FIG. 4 illustrates two separate regenerators, the
system may be configured having a single regenerator, such as where
the same catalyst is being used in both pyrolyzers. The solid
product may be sent to a first downstream process, the liquid
product may be sent to a second downstream process, and the gaseous
product may be sent to a third downstream process. For example, the
systems may include product separation units, such as condensers,
AGRs, or any other suitable separators to further refine the
product output of the system.
[0099] In the pyrolysis reactor/step, a portion of the volatile
matter of a solid carbonaceous feedstock is generated in the
presence of solid catalyst. This feedstock can be coal of any rank
(including lignite), biomass, or peat, as examples. In the reactor,
it is desirable to maximize the contact between the catalyst and
the solid feedstock in order to control yield and selectivity to
the greatest extent possible. From this standpoint, a fluidized-bed
or riser reactor would be desirable. The design of such a bed would
be done in order to maximize the mixing and avoid spontaneous
separation of the two solid substrates (catalyst and feedstock).
Given that mixing in fluid bed and riser reactors is largely
dictated by each solid's fluidization characteristics, which in
turn is driven by the particle size and shape, it would be
generally desirable to match size and shape of both the catalyst
and the solid feedstock. On the other hand, it is desirable to
separate the spent catalyst from the feedstock after the pyrolysis
step, because the spent catalyst needs to be regenerated and
re-used (e.g., due to its relative high cost compared to the
feedstock), and the remaining solid from the carbonaceous feedstock
needs to be removed and processed as a saleable co-product (along
with the pyrolysis gas). Most standard, industrially available
solid-solid separators typically rely on differences in size,
density, and shape either by using size exclusion, fluidization, or
classification in order to accomplish separation. Thus, there is an
inherent trade-off in the combination of these two unit-operations.
Either make the morphology of the two solids similar, thereby
providing good reactive contact in the pyrolyzer while sacrificing
efficient separation leading to product loss, catalyst loss, or
expensive and/or exotic separation schemes, or having poor mixing
in the reactor leading to low per-pass yields and/or poor
selectivity of the desired products. Due to these tradeoffs,
typically two separate unit operations are utilized to accomplish
reaction and product separation.
[0100] One way of eliminating the downstream solid-solid separator
(e.g., classifier) is to use a pyrolysis reactor configured to
utilize an immobilized catalyst while the carbonaceous material
enters and exits the reactor, such as via an inlet and an outlet.
Immobilization may advantageously allow an intrinsic separation of
the carbonaceous reactant from the catalyst without requiring an
additional separation unit operation provided downstream from the
reactor. However, one must also address the need to regenerate the
catalyst because the catalyst cokes as a normal consequence of
carrying out the pyrolysis reaction.
[0101] According to one illustrative method, three cycles are used.
In the first cycle, the pyrolysis reactor is charged with catalyst,
which may be preheated to reactor temperature. The reactor is
heated to the desired pyrolysis temperature, and coal is introduced
along with a fluidization gas. The fluidization gas may be any
non-oxidizing gas, including, but not limited to, nitrogen, helium,
neon, argon, hydrocarbon gases, recycled or fresh fuel gas,
recycled or fresh liquefiable petroleum gases, carbon dioxide, or
hydrogen. The fluidization provides mixing between the carbonaceous
reactant and the catalyst solid. The reactor may be run in (a) a
true batch mode, where a defined amount of carbonaceous reactant is
introduced initially and kept in the pyrolysis reactor for a
defined time, or (b) semi-batch, where the reactant is continuously
fed into the pyrolysis reactor and continually removed via
entrainment out of the pyrolysis reactor with fluidization and
product gases. In case (a), residence time is controlled by fixing
the dwell time of the charge, and then increasing the fluidization
gas velocity to entrain the solid products and pneumatically convey
the solid products out of the reactor, whereby it is recharged
again with new carbonaceous reactant feedstock. In case (b), the
gas velocity of the fluidization gas must exceed the entrainment
velocity of the solid carbonaceous reactant and the residence time
is controlled by adjusting the gas velocity to the desired amount
(but should always be greater than the entrainment velocity of the
solid carbonaceous feed). In both true batch and semi-batch mode,
the catalyst will eventually coke. This will be apparent as the
product selectivity will change. Production of hydrocarbon products
will drop, and usually, selectivity will change as well. When this
happens, fresh feedstock is stopped (or no more batches are added),
and the reactor is put into the second cycle.
[0102] In the second cycle, the spent catalyst and upgraded
carbonaceous product are separated. If it is being run as a true
batch, the fluidization velocity is increased such that the
upgraded carbonaceous product is entrained out of the reactor. If
it is being run as in semi-batch mode, the flow of carbonaceous
material feedstock into the reactor is stopped and fluidization
velocity (i.e., superficial gas velocity) may be increased. In
either case, once the upgraded carbonaceous product flow stops or
an acceptable portion of the upgraded product has exited the
reactor, then the reactor is ready for the third cycle.
[0103] In the third cycle, the reactor is then put into
regeneration mode. The reactor fluidization gas is changed from the
non-oxidizing gas, to an oxidizing gas, including, but not limited
to, air, oxygen, nitrous, or other nitrogen oxides. The oxidizing
gas may be further diluted by any inert gas. The coke is then
burned off the spent catalyst in an exothermic reaction. This will
create hot flue gas and the reactor may need to be cooled. This
heat and hot flue gas may be captured and utilized elsewhere in the
process, including but not limited to, drying of coal, raising
steam for downstream acid-gas removal, pre-heating of reactants for
the pyrolysis cycle, or direct flue gas injection into the
coal-fired boiler or into a heat recovery steam generator.
[0104] Once the catalyst is regenerated, the reactor could then be
returned to the first cycle, and pyrolysis would be started again.
It is noted that by using multiple reactors and valve switching,
this process could be configured in such a way that production
could advantageously be run in a continuous or near continuous
manner (in the case of batch-wise pyrolysis). For example, three
reactors could be used in a cyclic-swing configuration, with one of
the three reactors operating in each cycle at all times (i.e., one
reactor in the first cycle of pyrolysis, one reactor in the second
cycle of separation, and one reactor in the third cycle of
regeneration).
[0105] FIGS. 8-12 illustrate exemplary embodiments of pyrolysis
reactors that are configured to provide solid-solid separation in
the pyrolysis reactors, which may eliminate the need for providing
a downstream solid-solid separator. The pyrolysis reactors are
designed to allow for maximum contact of dissimilar (e.g., size,
density, shape) catalyst(s) and feedstock(s) to solve many of the
problems noted above. For example, the pyrolysis reactors of FIGS.
8-12 are configured to take advantage of dissimilar size, density,
and shape to maximize contacting; allow for independent control of
reactor residence time of the solid feedstock and catalyst, which
could substantially reduce the amount of catalyst recirculation by
enabling the catalyst to absorb more coke and by-products rather
than being forced out of the reactor before needed; and provide
separation within the reactor, possibly eliminating the need for a
separate unit operation to affect the solid/solid separation. The
reactors may be configured to use flow-fields, sieves, plates,
tilting, and/or solids transfer valves to continuously contact and
separate the solids. Each reactor may include two solids with
substantially different particle size diameter distributions (PSD),
such that a properly-sized sieve will not pass most of the solids
with the larger PSD and pass most of the solids with the smaller
PSD. The two solids may have substantially different fluidization
characteristics, such that a gas fluidization velocity exists where
one solid rises (the more buoyant solid), and one solid falls (the
less buoyant solid). A gas flow field may be configured to
encourage the less buoyant solid downward, and the more buoyant
solid upward. Each reactor may include one or more obstacles
configured to encourage contacting the two dissimilar solids on
their respective journeys through the reactor. Contacting may be
further increased by feeding counter-currently (i.e., the less
buoyant solid at the top, and taking it from the bottom, while the
more buoyant solid is fed to the bottom reactor and removed from
the top). Each reactor has the ability to adapt the flow field and
path of the particles to provide independent control of residence
time in the reactor of the solid feedstock and catalyst. The
catalyst may be larger and less buoyant than the solid feedstock,
and it may be desirable to keep the catalyst residence time
substantially greater than that of the solid feedstock. However,
each reactor may be adjustable to accommodate a number of
possibilities including, but not limited to, providing longer
residence for solid feedstock than the catalyst, or equal residence
time for the solid feedstock and the catalyst, as well as providing
solid feedstock that is less buoyant than that of the catalyst.
[0106] FIGS. 8-10 illustrate a pyrolysis reactor 503 configured to
provide solid-solid separation of a feedstock and a catalyst. The
reactor 503 includes a housing 530 having a generally elongated
tubular shape that defines an internal core chamber 532 that can be
divided into a plurality of sub-chambers 532a-532g with a varying
flow field to provide mixing and disengagement in each chamber. The
housing 530 has an inlet end 533 configured to introduce a
feedstock, such as low grade pulverized coal, into the housing. The
housing 530 has an outlet 534 at an opposite end from the inlet end
533. The upgraded feedstock, such as upgraded coal product, exits
via entrainment with any gases exiting the reactor via the outlet
end. Optionally, the reactor may include one or more fixed plates
in the core chamber. As shown in FIG. 8, the reactor 503 includes a
first fixed plate 536 that is provided between the inlet end 533
and a first plate assembly 541, and also includes a second fixed
plate 537 provided between the outlet end 534 and a sixth plate
assembly 546. Each fixed plate 536, 537 may be configured having a
plurality of holes (e.g., apertures, openings, orifices, etc.),
similar to or the same as the sieve plates discussed below.
[0107] The core chamber 532 can be divided into the sub-chambers
532a-532g by way of one or more movable plate assemblies. As shown
in FIG. 8, the reactor includes six plate assemblies 541-546.
However, other examples of reactors may be configured having a
greater or fewer number of plate assemblies.
[0108] Each plate assembly 541-546 may include at least one plate.
As shown in FIGS. 9 and 10, each plate assembly includes a solid
plate 548 (e.g., a plate having no orifices, holes, or apertures)
and a sieve plate 549 (e.g., a plate having at least one orifice,
hole, or aperture, and according to an exemplary embodiment a plate
having a plurality of apertures) where each plate (e.g., solid,
sieve) can be moved independently relative to the housing 530 (and
core chamber) to control the flow between a pair of adjacent
sub-chambers of the reactor 503. For example, each plate 548, 549
may be configured to slide between a fully open position, in which
the entire plate is positioned outside the core chamber 532 (e.g.,
outside the housing), and a fully closed position, in which the
plate covers the entire cross-sectional area of the core chamber.
Each plate may be positioned at a plurality of intermediate
positions between the fully open and fully closed positions. When a
solid plate 548 is in the fully closed position, flow through the
core chamber is completely blocked by the solid plate. When a sieve
plate 549 is in the fully closed position, flow around the plate is
prohibited, but flow through the one or more apertures of the sieve
plate can occur. At the various intermediate positions, the plates
influence the flow (e.g., increase the flow, restrict the flow).
The sieve plates 549 are configured to pass a feedstock (e.g., a
carbonaceous material, such as low grade coal) while preventing
catalyst from passing. Each plate assembly may be configured to be
moved from the same side (e.g., a top side) of the housing, such
that a gap between a distal end of the plate and the housing forms
on the same opposing side (e.g., a bottom side) of the housing 530
when the plates are at least partially open. Alternatively, the
reactors having two or more plate assemblies may be configured
having plate assemblies moving from different sides of the housing,
such as to provide gaps on alternating sides of the reactor.
[0109] The alignment of the reactor 503, such as relative to
vertical and horizontal, may be varied to change the relative angle
of the reactor. For example, the angle of the reactor may be
adjusted to be any angle from 0 (zero) degrees to 90 (ninety)
degrees. The reactor may be configured to form catalyst beds (e.g.,
an agglomeration of catalyst particles) having different sizes by
adjusting the plates and the angle of the reactor. The angle of the
reactor is used to create varying cross-sectional area in each of
the chambers. This changes the effective fluidization velocity
throughout the chamber. The velocity flow-field can be further
manipulated by varying the sieve plate and/or solid plate position
as well. In other words, the size of the catalyst beds may be
tailored by adjusting the plates and angle of the reactor. This
arrangement provides a very flexible geometry which advantageously
helps manipulate the solids and fluidization medium (usually a gas,
but possibly a liquid), to create maximum mixing while avoiding
plugging and bridging in the solids flow. FIG. 9 shows a portion of
the housing 530 and core chamber 532 having a single plate assembly
including a sieve plate 549 and a solid plate 548, which are able
to move relative to the housing 530 and independent of one another.
As shown, both the sieve plate 549 and the solid plate 548 are in
intermediate positions.
[0110] FIG. 10 shows some of the features of the geometry of a
mixing chamber (e.g., the mixing within the sub-chamber 532b). It
is readily apparent that the available cross sectional area for
flow varies markedly in the chamber. For the sake of understanding
the flow, but not limiting the reactor to any particular theory or
explanation, four aspects/features to controlling the flows and
mixing are further described. First, the line A.sub.1 denotes the
cross sectional area available for the less buoyant solid to fall
into the lower chamber. Second, the line A.sub.2 denotes the cross
sectional area available for the more buoyant solid and the
fluidization medium to rise from the lower chamber. Third, the line
A.sub.3 denotes the widest cross sectional area available for
transport in the chamber. Fourth, the arrow Q.sub.fluid denotes the
flow of fluidization medium in the sub-chamber. The velocity (u) of
the fluidization gas or of either solid can be roughly estimated by
dividing its volumetric flow by the cross sectional area available
for flow. Therefore, the downward flow of the less buoyant solids
at its most choked point would be given by position 1 and can be
calculated using calculation (1) below.
u.sub.1.sup.less buoyant solid=Q.sub.less buoyent solid/A.sub.1
(1)
[0111] The importance of this point is that solids can become
plugged due to bridging during in solids transfer and storage.
However, the upward fluidization velocity can assure that the
solids do not stagnate in the sub-chamber. The fluidization
velocity is determined by the cross sectional area at position 2
and can be calculated using calculation (2) below.
u.sub.2.sup.fluid=Q.sub.fluid/A.sub.2.gtoreq.u.sub.crit.sup.more
buoyant solid and u.sub.mf.sup.less buoyant solid (2)
[0112] Preferably, this fluidization velocity is greater than, or
equal to, the critical entrainment velocity of the more buoyant
solid. In some embodiments, the fluidization velocity is greater
than or equal to the minimum fluidization velocity of the less
buoyant solid. This will create a churning, turbulent zone as the
solids are forced upward by the fluidization media, preventing
solids plugging as the less buoyant particle falls out of the
chamber, and mixing the two dissimilar solids through the
turbulence.
[0113] Position 3 (e.g., line A.sub.3) in FIG. 10 is the point
where the maximum cross sectional area is available for flow. At
point 3, the fluidization velocity is the lowest, which can be
calculated using calculation (3) below. This allows a significant
amount of independent tuning to allow for separation and increase
contact time. If a degree of separation and good contacting is
desired, this velocity can be tuned to be less than the
fluidization velocity of the less buoyant solid, creating a
quiescent zone of lightly bubbling less buoyant particles and
forcing the more buoyant particles to pass through.
u.sub.3.sup.fluid=Q.sub.fluid/A.sub.3.ltoreq.u.sub.mf.sup.less
buoyant solid (3)
[0114] One advantage of a tilted reactor (e.g., relative to
vertical) is that the tilt can be used to adjust these various
velocities to maximize mixing and separation. Also, for the example
of pyrolysis, pyrolysis gas is evolved during the reaction and
flows together in the same direction with the fluidization gas,
increasing the overall amount of gas flow along the length of the
reactor, leading to increased superficial gas velocity along the
length of the reactor. This can be accounted for by varying the
tilt or the volume in each chamber (e.g., by adjusting the plate
spacing). Varying tilt can also be accomplished by series reactors,
or by bending the pipe. Additionally, the configuration of the
reactor of FIG. 8-10 allows the more buoyant and less buoyant
solids residence times to be controlled independently, as their
paths are different through the vessel. In a co-current, entrained
riser, all solids and fluidization media residence times are
roughly the same and dictated by the fluidization characteristics.
For the case where one of the solids is a catalyst, and the other
solid carbonaceous material is a feedstock to be reactive, it is
desirable to independently control these residence times. Finally,
in vessels with multiple staging, extra coal separation could be
accomplished by feeding the more buoyant material at a higher stage
than the bottommost stage, giving it more chance to disengage from
the less buoyant material. In this case, this lower stage (below
the injection of solid carbonaceous feed coal) could be used to
regenerate spent catalyst using an oxidizing gas.
[0115] The reactor 503 may include a second outlet 538 that is
configured to pass spent catalyst, such as to a regenerator. Also
shown in FIG. 8, the second outlet 538 is provided near the inlet
end 533 of the housing 530. For example, the second outlet 538 may
be provided in the bottom side of the first sub-chamber between the
first fixed plate and the first plate assembly. The reactor 503 may
include a second inlet 539 that is configured to introduce catalyst
(e.g., new catalyst, regenerated catalyst, a combination thereof).
Also shown in FIG. 8, the second inlet 539 may be provided near the
outlet end 534 of the housing 530. For example, the second inlet
539 may be provided in a top side of the seventh sub-chamber
between the second fixed plate and the sixth plate assembly. This
arrangement may advantageously utilize gravity in bringing the
catalyst from the second inlet toward the second outlet.
[0116] FIG. 11 illustrates another illustrative embodiment of a
pyrolysis reactor 603 configured to provide solid-solid separation
of a feedstock and a catalyst. The reactor 603 includes a housing
630 having a generally elongated tubular shape extending from a
first end 631 to a second end 632. According to one example, the
reactor 603 is aligned substantially vertically, with the first end
631 at a bottom side and the second end 632 at a top side.
According to other examples, the reactor 603 can be tilted, such as
to be aligned at an oblique angle relative to vertical. The reactor
603 may include one or more plate assemblies that are configured to
divide an internal core chamber 640 into a plurality of
sub-chambers (e.g., the sub-chambers 641-646).
[0117] The reactor 603 may include one or more inlets. As shown in
FIG. 11, disposed at the first end 631 is a first inlet 633 that is
configured to receive a fluidizing gas. Also disposed near the
first end 631 is a second inlet 634 that is configured to introduce
a feedstock, such as low grade coal, into the reactor 603. For
example, the second inlet 634 may be configured to introduce
feedstock into a second sub-chamber 642 of the reactor 603.
Disposed near the second end 632 is a third inlet 635 that is
configured to introduce catalyst (e.g., new catalyst, regenerated
catalyst, a combination thereof) into the reactor 603. For example,
the third inlet 635 may be configured to introduce catalyst into
the sixth sub-chamber 646.
[0118] The reactor 603 may include one or more outlets. As shown in
FIG. 11, the reactor 603 includes a first outlet 636, which is
configured to remove spent catalyst from the reactor, and a second
outlet 637, through which upgraded feedstock, such as an upgraded
coal product, is recovered. The first outlet 636 may be disposed
near the first end 631. For example, the first outlet 636 may be
configured to remove spent catalyst from the first sub-chamber 641.
The second outlet 637 may be disposed near the second end 632. For
example, the second outlet 637 may be configured to remove upgraded
coal product and to remove off gases (e.g., pyrolysis product gas
and/or fluidization gas) from an outlet sub-chamber that is
downstream from the sixth sub-chamber 646. According to another
example, the off gas may be outlet via the second outlet 637, such
that the upgraded feedstock and off gases exit the reactor 603
together. Thus, the off gases and upgraded feedstock may be
separated inside or outside the reactor 603.
[0119] As noted above, the reactor 603 may include one or more
plate assemblies configured to define the reactor into
sub-chambers. As shown in FIG. 11, the reactor 603 includes seven
plate assemblies 651-657, which divide the reactor 603 into
sub-chambers 641-646, along with an inlet sub-chamber and an outlet
sub-chamber. Each plate assembly includes one or more plates. As
shown, each of the first and seventh plate assemblies 651, 657
include a single plate configured as a sieve plate with a plurality
of apertures in the plate. The size of the apertures may be
tailored. According to an exemplary embodiment, the size of the
apertures are configured to allow the particles of the feedstock to
pass through the apertures, while preventing the particles of
catalyst from passing through the apertures. Thus, the sieve plates
may separate catalyst and feedstock while the feedstock flows
through the reactor from sub-chamber to sub-chamber. The plates of
the first and seventh plate assemblies 651, 657 are fixed relative
to the housing 630. The second thru sixth plate assemblies 652-656
may be configured to include a sieve plate and a second plate
disposed adjacent the sieve plate, where the second plate has an
opening disposed in a solid portion. The feedstock may pass through
the sieve plate and the opening in the second plate. According to
another example, each of the second thru sixth plate assemblies
652-656 include a single plate having a solid portion and a sieve
portion, where the sieve portion is configured to restrict the flow
of catalyst but allows feedstock to flow through the apertures of
the sieve portion. The sieve portion of the second thru sixth plate
assemblies 652-656 may be offset from a longitudinal axis 658, such
as, for example, in an alternating manner as shown in FIG. 11,
where the second, fourth, and sixth sieve plates are on a similar
side of the longitudinal axis and the third and fifth sieve plates
are on a similar side that is opposite to the side of the second,
fourth and sixth sieve plates. This offset arrangement of the sieve
portions may advantageously induce an alternating flow of feedstock
through the reactor 603, which may create more exposure of the
feedstock to the catalyst and increase residence time.
[0120] As shown, each of the second thru sixth sub-chambers 642-646
acts as a staged reaction zone, where the feedstock is exposed to
catalyst to form an upgraded feedstock as a result of the reaction.
The first sub-chamber 641 serves as a disengagement zone, such that
the spent catalyst passing through the second plate assembly 652
can be recaptured for regeneration via the outlet 636.
[0121] The reactor 603 may be configured to include one or more
transfer valves (e.g., bypass valve, slide valve, gate valve, etc.)
configured to control the flow through reactor 603. For example, a
valve 660 may be provided to control the flow of catalyst between
each pair of adjacent sub-chambers. A first valve 660 fluidly
connects the first and second sub-chambers 641, 642 by way of a
first pipe extending from the first sub-chamber 641 to the valve
660 and a second pipe extending from the second sub-chamber 642 to
the valve. Similarly, second, third, fourth, and fifth valves 660
fluidly connect the second and third sub-chambers 642, 643, the
third and fourth sub-chambers 643, 644, the fourth and fifth
sub-chambers 644, 645, and the fifth and sixth sub-chambers 645,
646 sub-chambers, respectively. Each of the second, third, fourth,
and fifth valves 660 include a pipe connecting each sub-chamber
with the valve. Each valve 660 is adjustable to change (e.g.,
increase, decrease) the flow rate through the valve.
[0122] A valve may be provided to control the flow through each
inlet and/or outlet of the reactor 603. For example, a valve may be
provided to control the flow of feedstock through the first inlet
634 and/or the catalyst through the second inlet 635. Also, for
example, a valve may be provided to control the flow of spent
catalyst through the first outlet 636 and/or the flow of upgraded
feedstock through the second outlet 637.
[0123] The reactor 603 of FIG. 11 accomplishes many of the desired
effects disclosed in this application by manually controlling the
solids flow of the more buoyant particles including particles of a
solid carbonaceous material feedstock, using transfer valves for
controlling the downward flow of the less buoyant particles
including catalyst, and preventing upward flow of catalyst by
entirely dividing the core chamber into sub-chambers with plate
assemblies including plates (e.g., sieve plate, block plate, etc.).
In this configuration, there is no open cross-section area allowing
complete free flow of solids, since the flow of catalyst particles
is restricted. As with a diagonal fluid bed, this reactor is
designed to force the more buoyant particle upward, and uses sieves
to trap the less buoyant particle in each sub-chamber.
[0124] The reactor 603 of FIG. 11 may avoid packing of the catalyst
at the bottom by partitioning the reactor into zones (e.g.,
sub-chambers). The zones may be of variable volume to account for
increased gas flow as pyrolysis gas is evolved during the reaction
it commingles and flows together and in the same direction with the
fluidization gas, increasing the overall amount of gas flow along
the length of the reactor. By having plates that are mostly solid,
but include sieves in part of the plate designed to let only the
feedstock (e.g., coal) pass, the reactor separates the solids
(e.g., feedstock, catalyst), which may advantageously eliminate the
need for solid-solid separation outside the reactor 603.
Preferably, the cross sectional area of the partial sieves creates
a local velocity higher than the critical entrainment velocity of
the more buoyant particles. More preferably, the cross sectional
area of partial sieves can be designed to create local velocities
greater than the minimum fluidization velocity of the less buoyant
particles, forcing a churning motion. The location of the sieve
openings/apertures can be varied from sieve to sieve to force the
feedstock through a tortuous path in the reactor. The slide or gate
valves may occasionally be opened to allow catalyst to pass
downward in the reactor. The frequency may be determined by a
coking rate. These could also simply be discharges to a common
catalyst collection receptacle. This could also be metered
continuously by typical solids metering valves, such as a rotary
valve or auger. Advantageously, the lowest sub-chamber (e.g., the
first sub-chamber 641) is provided below the coal feed point (e.g.,
the inlet 634) to allow any entrained coal time to disengage.
Advantageously, the disengagement zone may become the regeneration
zone, allowing hot flue gas to pass into the pyrolyzer. In this
case the fluidizing gas could contain an oxidizing component, such
as oxygen. Also, the oxidizing gas may, preferably, be enriched air
or oxygen, such as to avoid the system becoming overloaded with
nitrogen.
[0125] FIG. 12 illustrates another illustrative embodiment of a
pyrolysis reactor 703 configured to provide solid-solid reactor of
a solid carbonaceous material feedstock and a catalyst. The
pyrolysis reactor 703 also provides solid-solid separation of an
upgraded solid carbonaceous product and the spent catalyst. In
particular, the reactor 703 is configured to utilize a fluidized
catalyst (e.g., bubbling bed of catalyst) that is not entrained, as
discussed above.
[0126] The reactor 703 includes a housing 730 having a first (e.g.,
lower) section 731 and a second (e.g., upper) section 732. The
first section 731 has a generally tubular shape defining an
internal lower chamber, and the second section 732 has a generally
conical shape defining an internal upper chamber. A frusto-conical
intermediate portion may interconnect the first section 731 and the
second section 732. The reactor 703 may include one or more than
one inlets. A first feed pipe 741 is disposed at an end of the
second section 732 and is fluidly connected to a first dipleg 751
extending into a fluidized regime 735. A second feed pipe 742 is
disposed at the end of the second section 732 and is fluidly
connected to a second dipleg 752 extending into the fluidized
regime 735. A feedstock may be introduced into the internal chamber
of the reactor 703 through one of the first and second feed pipes
741, 742, while a catalyst may be introduced into the internal
chamber via the other of the first and second feed pipes. As shown,
the reactor 703 includes a third inlet that is disposed at an end
of the first section 731 (e.g., the end opposite the end of the
second section 732) and configured to receive fluidization gas from
pipe 743. The third inlet is configured to introduce fluidization
gas into the internal chamber via a fluidization gas distributer
745. Reference numeral "739" denotes a fluidized bed level (e.g.,
an adjustable interface of dense bed below with dilute phase solids
above).
[0127] The reactor 703 may include one or more than one outlet.
Also shown in FIG. 12, a first outlet pipe 761 is disposed at the
second section 732 (e.g., the end thereof). The first outlet pipe
761 is configured to discharge fluidization gas, pyrolysis product
gases and the upgraded carbonaceous product. A second outlet pipe
762 is disposed at the first section 731 (e.g., the end thereof)
and configured to discharge the spent catalyst. For example, the
second outlet pipe 762 may surround the third inlet and pipe 743.
Thus, the upgraded carbonaceous product exits the reactor 703 via
the first outlet 761 and the spent catalyst exits the reactor 703
via second outlet pipe 762. In experimental studies of this
reactor, we have demonstrated that the reactor can be run such that
solids exiting the reactor through exit port 761 contain a weight
ratio less than 1 weight part catalyst per 100 parts of
carbonaceous product.
[0128] Now, a comparison including actual data recovered from a
reactor similar to the reactor 703, which was configured to run
first as a riser reactor (i.e., Example 1) and then second as a
hybrid elutriating riser bed (HERB) reactor (i.e., Example 2), will
be discussed. In the first run, the riser reactor was configured to
operate providing a partial catalytic pyrolysis of coal. The
reactor was configured having a 3/4 inch diameter pyrolysis reactor
with 8 feet of heated height, which was fed with a coal and
catalyst mixture. The reactor also had an unheated disengagement
zone, which was approximately 7 feet high.times.3/4 inch diameter,
provided above the heated zone. Catalyst and coal entered the
reactor from the bottom. Additionally, nitrogen was provided as a
fluidization gas via a sparger at the bottom of the reactor. Gases
and solids were taken off the top of the reactor where they entered
a cyclone separator where solids and gases were separated at the
effluent temperature of the pyrolysis reactor. Product gases were
then sampled with a gas chromatograph (GC) to determine light
components (e.g., components lower than Benzene), and the heavier
components were condensed in a liquid trap and then injected into a
GC column for quantitative analysis. The spent catalyst and
upgraded coal product were weighed to determine catalyst recovery
efficiency and coal conversion. The upgraded coal product was
analyzed for carbon content, volatile matter, ash, and sulfur. In
the embodiments described in this application, we have generally
described the catalyst as being larger, denser, or less mobile than
the carbonaceous material. This choice is driven by economic rather
than technical considerations. The economic drivers favor
configuring the catalyst as the larger, denser, or less mobile
material because the larger, denser, or less mobile material tends
to be handled less and tends to be transported less. Because of the
reduced handling, losses will be minimized and as the catalyst is
usually more expensive than the carbonaceous material, it is
generally better to minimize the catalyst losses. However, it is
just as valid to reverse the roles of the catalyst and the
carbonaceous material. What is required is differences in
densities, sizes, or mobility; which material is larger, denser, or
less mobile has no impact on the operability or effectiveness of
the process. Therefore, it should be understood that any
embodiments specifically referring to the catalyst being larger,
less mobile, or denser than the CM, also implicitly disclose
configurations where the CM is larger, less mobile, or denser than
the catalyst. Commensurately, all locations of the CM and catalyst
in process schematics would be inverted as well.
[0129] During start-up, the reactor was heated by supplying hot
catalyst from an attached heated regenerator vessel which served as
the catalyst reservoir during the studies. The catalyst was
recirculated between the regenerator vessel and the pyrolysis
reactor until a steady state temperature was attained. Catalyst
flow was controlled by a gate valve between the regenerator vessel
and the pyrolysis reactor. Flow rate was calibrated by gate valve
position and weight beforehand, and validated by total weights
before and after the run. Once the temperature was attained, coal
feed was introduced at the bottom of the pyrolysis reactor via an
auger. Feed rate of coal was controlled by the speed of the auger.
At the same time, the combined flow of upgraded coal product and
spent catalyst from the riser was diverted to a product collection
vessel. The run was carried out until the catalyst in the
regenerator vessel (reservoir) was depleted.
[0130] Process conditions and results are contained in Table 1
(below). Although the experiment ran steady and in control, a
number of shortfalls of this configuration were identified. First,
as a practical matter, it was difficult to run for extended periods
of time, because the catalyst consumption was high. The catalyst
came out with the product and had to be separated in another step.
Second, it was clear from the results that an optimal contact time
for the catalytic pyrolysis reactions was not provided. When
compared to results in the smaller lab apparatus (FIGS. 5-7),
conversion of coal was low, and yields of all hydrocarbon and fuel
products were low.
[0131] In the configuration of Example 1, increasing residence time
was difficult because it required a decrease in fluidization
velocity, which was discovered to result in a loss of entrainment
of the catalyst. However, it was determined that upgraded coal
product could be successfully separated from catalyst by adjusting
fluidization velocity to thereby enable elutriation of the
particles of coal to pass through a bubbling bed of catalyst. In
the vessel, there was adequate mixing of the coal with catalyst in
the lower bubbling bed zone, and because the coal was less dense
and smaller in average particle size, the coal would elutriate out
of the bed while the catalyst stayed behind. It is postulated that
for this to occur, the fluidization velocity was adjusted to an
intermediate velocity provided between the two entrainment
velocities associated with each of the two particle types, coal and
catalyst. This vessel is considered a hybrid reactor, because it
acts as a riser with respect to coal flow and a bubbling, fluidized
bed with respect to catalyst, while accomplishing an elutriation
separation. Thus, this reactor is described as a HERB reactor in
this application.
[0132] In Example 2, the same reactor configuration as Example 1
was used, but the procedure was modified to enable it to run as a
HERB reactor, to carry out partial pyrolysis of coal. First, an 8
feet heated section of the riser was filled with fluidized
catalyst. Then the coal was fed into the base of the pyrolyzer.
During the run, no fresh catalyst was added.
[0133] Despite the differences between Example 1 and Example 2,
Example 2 provides a number of advantages over Example 1. First,
Example 2 is able to run for much longer extended periods of time,
compared to Example 1, while using much less catalyst. Second,
Example 2 serves the dual purpose of separating the upgraded coal
product from the catalyst in addition to carrying out the catalytic
pyrolysis reaction. The results show that very little catalyst
escaped the pyrolysis reactor during the run. Without being bound
by theory or explanation, it is believed that the most relevant
factor in achieving good selectivity and conversion in Example 2,
the HERB pyrolysis reactor configuration, is having a high
concentration of catalyst in the coal, to promote more favorable
conditions for controlled selectivity and conversion. This is
supported by the results in Table 1, in which fuels yield increases
from 8.43% in Example 1 to 22.80% in Example 2, more valuable fuels
(e.g., condensable fuels) increases with the lighter components
rising from 3.74% in Example 1 to 7.42% in Example 2, and the most
valuable BTEX components rise from 0.29% in Example 1 to 2.18% in
Example 2. The results are indicative of effective contacting of
the solid carbonaceous feedstock (e.g., coal) with a selective and
active catalyst.
[0134] It is noted that although on a superficial basis, the
residence (i.e., contact) time of the solid carbonaceous material
and catalyst in Example 2 is longer than in Example 1 (see line 14
of Table 1), if one corrects for the percent volume of the reactor
having catalyst, then a calculated effective contact time of the
coal with catalyst is actually lower in Example 2. For example,
making such a correction assuming that approximately 76% of the
reactor volume is catalyst, the effective contact time of the coal
in Example 2 is 0.65 seconds compared to 3.77 seconds in Example 1.
Therefore, while we set out to increase contact time with this
reactor with the desire of increasing extent of reaction, we in
fact, decreased the residence time of coal, and yet surprisingly,
the extent of reaction substantially increased. This can be
explained in part by the theory that the effective residence time
during which the feed coal was in active contact with catalyst was
actually higher in Example 2.
TABLE-US-00001 TABLE 1 Working parameters of the reactors of
Examples 1 and 2 discussed above, along with recovered products
according to these two examples. Example 1: Example 2: Riser HERB
1. Run duration, minutes 8.9 70.0 2. Raw coal feed (dry basis), kg
0.269 0.531 3. Upgraded coal product out (dry basis), kg 0.201
0.344 4. Coal feed rate, kg/hr 1.809 0.455 5. Fresh catalyst feed
rate, kg/hr (for HERB: initial charge/run time) 11.158 0.325 6.
Riser lift gas velocity (in riser, corrected for T P), m/s 1.476
0.895 7. Riser lift gas volumetric flow, m.sup.3/s 4.21E-04
2.55E-04 8. Density of coal in reactor, kg/m.sup.3 1.226 0.509 9.
Catalyst fluidization state (riser, fluid) riser fluid 10. If
fluid, kg of catalyst in reactor N/A 3.81E-01 11. Density of
catalyst in reactor, kg/m.sup.3 4.62 548 12. Bulk density of
catalyst, kg/m.sup.3 720 720 13. Available void volume % not
occupied by catalyst (1-Bulk/Bed 99% 24% density) 14. Coal
Residence time, seconds 1.65 2.72 15. Corrected coal residence time
based on available void volume 1.64 0.65 16. Catalyst/coal ratio
(based on fresh catalyst and coal feeds) 3.77 0.41 17. Catalyst to
coal ratio based on bed densities 3.77 1077.46 18. Reactor Average
temperature, C. 491.61 494.09 PROCESS PERFORMANCE, ALL VALUES IN KG
PRODUCED PER 100 KG OF DRY COAL FEED 19. Raw coal conversion 25.2
35.1 20. Total fuels yield (ex. H.sub.2S), kg per 100 kg 6.89 17.67
21. Total non-condensable fuel gases 3.51 10.38 22. CO 1.80 4.80
23. H.sub.2 0.02 0.20 24. METHANE 0.61 2.53 25. ETHYLENE 0.85 2.05
26. ETHANE 0.23 0.79 27. ACETYLENE 0.00 0.01 28. LPG: light
condensable fuels (ex. BTX and higher 3.19 5.85 hydrocarbons) 29.
PROPYLENE 1.66 2.72 30. N-PROPANE 0.18 0.28 31. PROPADIENE 0.00
0.02 32. CYCLOPROPANE 0.00 0.00 33. METHYLACETYLENE 0.00 0.00 34.
ISOBUTANE 0.11 0.08 35. ISOBUTYLENE 0.37 0.62 36. 1-BUTENE 0.16
0.28 37. 1,3-BUTADIENE 0.05 0.54 38. N-BUTANE 0.05 0.05 39.
TRANS-2-BUTENE 0.16 0.20 40. CIS-2-BUTENE 0.16 0.21 41. CYCLOBUTANE
0.00 0.00 42. ISOPENTANE 0.03 0.03 43. 1-PENTENE 0.09 0.07 44.
N-PENTANE 0.03 0.03 45. TRANS-2-PENTENE 0.00 0.07 46. CIS-2-PENTENE
0.06 0.03 47. 2-METHYL-2-BUTENE 0.00 0.09 48. 3-METHYLPENTANE 0.00
0.00 49. 2-METHYLPENTANE 0.00 0.00 50. 1-HEXENE 0.00 0.08 51.
N-HEXANE 0.08 0.45 52. 2,3-DIMETHYLPENTANE 0.00 0.00 53.
2-METHYL-1-BUTENE 0.00 0.00 54. BTEX total 0.19 1.43 55. BENZENE
0.11 0.80 56. Toluene 0.08 0.56 57. Xylene 0.00 0.07 58. HIGHER AND
HETEROATOM CONTAINING 0.00 0.00 HYDROCARBONS 59. SULFUR GASES 60.
H.sub.2S 1.37 2.71 61. SO.sub.2 0.00 0.00 62. Other sulfur gases
0.18 0.24 FEED COAL ANALYSIS, WT % DRY BASIS 63. Fixed Carbon 30.9
30.9 64. Volatile Matter 34.4 34.4 65. Ash 34.75 34.75 66. Total
sulfur 3.9 3.9 67. Pyrite 0.546 0.546 68. Sulfate 0.026 0.026 69.
Organic 3.315 3.315
[0135] It should be appreciated that this process can be used on a
variety of carbonaceous materials with varying amounts of volatile
matter, ash, fixed carbon, sulfur, and heating values (often
referred to as rank). However, through testing various coals, we
have found that even disparate ranks of coal and carbonaceous
materials can be compared by looking at conversion and yields based
on the feed carbonaceous material.
[0136] To better elucidate this point, the following table contains
yield calculations and others figures of merit based on the above
data. Additionally, we have summarized the ranges observed in all
of our continuous reactor runs in the following table, as well as
our projected ranges based on our empirical knowledge and based on
simulations using mass and energy balances. It should be stressed
that these are non-limiting ranges for the practice of the
processes/systems of this application.
TABLE-US-00002 TABLE 2 Figures of merit in process performance
calculated from data in Table 1. Example 1: Example 2: Riser HERB
1. kg of upgraded coal per 100 kg of dry coal feed 74.7 64.8 2. kg
of sulfur in upgraded coal per 100 kg of sulfur in coal feed 41.4
35.9 3. kg of ash in upgraded coal per 100 kg of ash in coal feed
97.4 4. kg of fixed carbon in upgraded coal per 100 kg of fixed
carbon in 68.1 coal feed 5. kg of volatile matter in upgraded coal
per 100 kg of volatile matter in 26.9 28.7 coal feed Hydrocarbon
yields based on volatile matter content 6. kg of non-condensable
fuels produced per 100 kg of volatile matter in 10.2 30.2 coal feed
7. kg of LPG produced per 100 kg of volatile matter in coal feed
9.3 17.0 8. kg of BTEX per kg of volatile matter in coal feed 0.6
4.2 9. kg of all other hydrocarbons per kg of volatile matter in
coal feed -- -- 10. total kg of all hydrocarbons per kg of volatile
matter in coal feed 20.0 51.3 Hydrocarbon selectivities based on
volatile matter converted 11. kg of non-condensable fuels produced
per 100 kg of volatile matter 14.0 42.3 converted in reaction 12.
kg of LPG produced per 100 kg of volatile matter converted in 12.7
23.9 reaction 13. kg of BTEX produced per 100 kg of volatile matter
converted in 0.8 5.8 reaction 14. kg of all other hydrocarbons and
heteroatoms produced per 100 kg of -- -- volatile matter converted
in reaction 15. total kg of all hydrocarbons per kg of volatile
matter converted in 27.4 72.0 reactor 16. HHV fuel value of input
coal, as received, MJ/kg 12.8 12.8 17. HHV fuel value of output
coal, as received, MJ/kg 13.7 14.7 18. Upgrade factor: HHV of
output coal/HHV input coal (as received 1.07 1.15 basis) 19. Weight
hour space velocity, (kg/hr dry coal feed)/(kg catalyst) 3.93
1.07
TABLE-US-00003 TABLE 3 Ranges in figures of merit in process
performance observed in continuous runs (both HERB and riser
configurations), and projected based on lab data, continuous runs,
and simulations based on mass and energy balances. Range in
Expected continuous coal ranges feed reactors (inclusive) 1. kg of
upgraded CM per 100 kg of dry CM feed 55-100 40-100 2. kg of sulfur
in upgraded CM per 100 kg of sulfur in CM feed 25-79 0-80 (overall)
0-50 (organic) 50-100 (pyritic) 0-50 (sulfate) 3. kg of ash in
upgraded CM per 100 kg of ash in CM feed 93-100 60-100 4. kg of
fixed carbon in upgraded CM per 100 kg of fixed carbon 61-100
50-100 in CM feed 5. kg of volatile matter in upgraded CM per 100
kg of volatile 23-73 0-90 matter in CM feed Hydrocarbon yields
based on volatile matter content 6. kg of non-condensable fuels
produced per 100 kg of volatile 1-39 0-40 matter in CM feed 7. kg
of LPG produced per 100 kg of volatile matter in CM feed 1-21 0-40
8. kg of BTEX per kg of volatile matter in CM feed 0-9 0-40 9. kg
of all other hydrocarbons per kg of volatile matter in CM 0-0 0-20
feed 10. total kg of all hydrocarbons per kg of volatile matter in
CM feed 2-62 10-90 Hydrocarbon selectivities based on volatile
matter converted 11. kg of non-condensable fuels produced per 100
kg of volatile 1-42 0-60 matter converted in reaction 12. kg of LPG
produced per 100 kg of volatile matter converted in 1-23 0-60
reaction 13. kg of BTEX produced per 100 kg of volatile matter
converted in 0-9 0-60 reaction 14. kg of all other hydrocarbons and
heteroatoms produced per 100 kg 0-0 0-40 of volatile matter
converted in reaction 15. total kg of all hydrocarbons per kg of
volatile matter converted 2-71 2-100 in reactor 16. Upgrade factor:
HHV of output solid material/HHV input solid 1.04-1.62 0.9-1.80
material (as received basis) 17. Weight hour space velocity, (kg/hr
dry coal feed)/(kg catalyst) 0.31-12.5 0.2-20 18. Catalyst to coal
feed ratio, (kg/hr dry catalyst feed)/(kg/hr coal 0.08-72 0-100
feed) 19. kg of CO.sub.2 produced per 100 kg of dry coal feed 1-20
1-25 20. kg of CO.sub.2 produced per 100 kg of volatile matter feed
2-57 2-65
[0137] These figures of merit are illustrative of the unique
ability of this processes/systems of this application to carry out
upgrading of carbonaceous materials while providing beneficial
materials and in process that has superior operability to prior
methods. Further explanation of the significance in reference to
row numbers is as follows:
[0138] Row 2 is a measure of the weight fraction of sulfur retained
in upgraded CM. This process reduces the sulfur in upgraded CM.
Without wishing to be bound by any theory or explanation, our
results suggest that organic sulfur and sulfates in the
carbonaceous material is liberated as hydrogen sulfides, and only
pyritic sulfur is retained. We expect the pyritic sulfur to stay
with the ash, so the retention of pyritic sulfur to be similar to
the ash retention in the upgraded CM.
[0139] Row 3 is a measure of the weight fraction of ash retained in
the upgraded carbonaceous material. This process is unique in that
most of the ash in the carbonaceous material is retained in the
carbonaceous material. This is a key advantage of this process:
very little ash is free to sorb on the catalyst and clog the
catalyst pores. Ash accumulation on catalyst is a known
irreversible deactivation mechanism of most pyrolysis catalysts, so
our process will suffer less from this problem.
[0140] Row 4 is a measure of the weight fraction of fixed carbon
retained in the upgraded carbonaceous material. Most, and in many
cases, all, of the fixed carbon is retained in the upgraded
carbonaceous product. Fixed carbon is known to be difficult to
pyrolyze, particularly at the temperatures of this process, so
without being bound to any particular theory or explanation, we
believe that the fixed carbon not retained in the upgraded
carbonaceous material is either oxidized by oxygen in the CM, or
becomes coke on the catalyst. In other words, no fixed carbon is
transformed into hydrocarbon products.
[0141] Row 5 is a measure of the weight fraction of volatile matter
retained in the upgraded carbonaceous material. Without being bound
to any particular theory or explanation, we believe that the
volatile matter is the major source for all hydrocarbons liberated
in this process because the fixed carbon is much more difficult to
pyrolyze. As can be seen from our experimentally observed ranges,
we typically retain some portion of the volatile matter. However,
we chose to keep some volatile matter in the product coal because
our desired end product in these experiments was a coal that can be
efficiently burned in a boiler. (A coal that is efficiently burned
in a boiler is often referred to as a "steam coal"). Steam coals
require some volatile matter so that they may be easily ignited.
Without volatile matter, a coal will not burn efficiently. However,
coals with low volatile matter are often useful as coking coals,
used in steelmaking. Our process may be run at more aggressive
conditions (e.g., higher temperature, residence time) to convert
most or all of the volatile matter giving a coking coal, suitable
for use in steelmaking.
[0142] In rows 6-10, we recalculate fractional yields by weight
based on volatile matter in the CM rather than the total CM weight.
Based on our non-limiting working theory, we believe that as most
of the hydrocarbons come from the volatile matter, it makes sense
to base yields and selectivities on volatile matter content. We
have seen that this allows us to predictably compare performance
across various ranks of carbonaceous feedstocks.
[0143] In rows 11-15, we calculate fractional selectivities by
weight based on volatile matter converted in the process. The total
selectivity to hydrocarbons (Row #15) is a good measure of how
effective the process is at utilize the converted volatile matter.
A perfect process would approach 100%. It can readily be seen the
effectiveness of running the reactor in the HERB configuration, as
over 70% of the converted volatile matter yields hydrocarbons.
[0144] In row 16, we calculate an upgrade index. This upgrade index
is defined as the ratio of the heating value of the upgraded
carbonaceous product and the heating value of the feed carbonaceous
material (on an as received basis). A number of factors determine
this index, and although we often increase the heating value, it is
not necessarily a higher value because a number of factors move the
value in opposite directions. For example, nearly all of the
moisture is removed from the feed material. This will increase the
heating value and increase the efficiency in a boiler. Also, for
example, much of the volatile matter is removed from the feed
material. Depending on the relative heating value of the volatile
matter to the remainder of the components in the CM, this can
either increase or decrease the product's heating value. For
example, if the ash content is high in the feed material, the
non-volatile contents in the CM (Fixed Carbon+Ash) will be low
relative to the volatile matter, so reduction in volatile matter
will reduce heating value. Also, for example, most of the oxygen is
removed from the feed material. This has the effect of increasing
the heating value of the product relative to the feed material.
Based on the above factors, we would expect a higher upgrade index
for carbonaceous feedstocks with high oxygen, high moisture, and
low ash, and vice versa.
[0145] In rows 19 and 20 (of Table 3), it should be noted that the
CO.sub.2 production may vary depending on the type of carbonaceous
matter used.
[0146] Now, an illustrative product composition of a mild catalytic
pyrolysis reactor will be described. An illustrative result of the
pyrolysis reactor is presented in Table 4 (below). The product
composition is based on an analysis of experimental laboratory
results of a low-grade coal catalytically pyrolyzed at 400.degree.
C. using a zeolite catalyst. Approximately 45% of the volatile
matter was converted to gaseous, liquid, and upgraded solid
product, such as upgraded coal product. The level of conversion may
be tailored (e.g., increased, reduced), such as by increasing or
reducing the reaction temperature and/or reactor residence time.
The usable products contain valuable olefins and aromatics. The
results of the catalytic pyrolysis showed no compounds larger than
C.sub.12, indicating that little or no tar or other highly viscous
material handling would be necessary if this catalytic pyrolysis
reaction was scaled-up to a larger commercial size and practiced
precisely as it was in the small-scale lab experiment.
TABLE-US-00004 TABLE 4 Estimated chemical composition of product
(hydrocarbons only) for low-grade coal sample catalytically
pyrolyzed with a zeolite catalyst. Carbon # Weight % Category
Weight % C.sub.1 8.55 Paraffins 25.73 C.sub.2 12.19 Olefins 42.59
C.sub.3 27.97 Aromatics 26.80 C.sub.4 14.56 Oxygenated 4.88 C.sub.5
1.70 hydrocarbons C.sub.6 3.45 C.sub.7 10.47 C.sub.8 14.30 C.sub.9
1.01 C.sub.10 2.98 C.sub.11 0.59 C.sub.12 2.23
[0147] Now, the results of experiments using an experimental test
setup are shown, graphically, in FIGS. 5-7. The experimental system
included a fluidized bed reactor. FIG. 5 compares the yields of
various compounds including lower molecular weight hydrocarbons of
the system using a catalyst and sand at 400.degree. C. FIG. 6
compares the yields of various compounds including lower molecular
weight hydrocarbons from the system using a catalyst at 400.degree.
C., sand at 400.degree. C., and the catalyst at 600.degree. C. FIG.
7 compares the yields of various compounds from the system using a
catalyst at 400.degree. C., sand at 400.degree. C., and the
catalyst at 600.degree. C.
[0148] The systems and processes, as disclosed herein, may be
integrated with other industrial applications. Examples of such
industrial applications include, but are not limited to, coal-fired
power generation facilities (e.g., plants), gas to liquid (GTL)
facilities, coal/coke/biomass gasification (CCBG) facilities, blast
furnace (BF) facilities, and oil refining and/or steam cracking
facilities. Coal-fired power generation facilities may serve as an
outlet for waste heat from the systems, excess steam from the
systems, fuel gas for a co-firing boiler, fuel gas use as staged
NO.sub.x reduction (e.g., rich reagent injection, as a so-called
"reburn" stream, etc.), and/or upgraded coal to a boiler. GTL
facilities may be used with the systems to upgrade lower value fuel
gas and/or other hydrocarbons, especially light hydrocarbons (e.g.,
C.sub.1-C.sub.4), into other higher value useful heavier liquid
hydrocarbons (e.g., liquid transportation fuels) by any suitable
method. For example, GTL facilities may be used with the systems to
convert the hydrocarbons into syngas and syngas into
Fischer-Tropsch liquids, to convert syngas into methanol and
methanol into gasoline, as an oligomerizer of light olefins, such
as ethylene-propylene-butylene, into gasoline range hydrocarbons,
for the alkylation of iso-butylene with butane to form iso-octane
fuel additive, as well as for other conversions. CCBG facilities
may serve as an outlet for waste heat from the systems, excess
steam from the systems, fuel gas for co-feeding to a gasifier,
upgraded coal as feed to a gasifier, fuel gas as co-feed to raw
synthesis gas (e.g., supply of H.sub.2 and CO), and/or fuel gas and
hydrocarbons to steam reforming to supply additional H.sub.2/CO. BF
facilities could use upgraded coal from the systems as a substitute
for metallurgical coke feed or as a pulverized coal injection (PCI)
feed in the facility. Oil refining and/or steam cracking facilities
may serve as an outlet for waste heat and/or excess steam from the
systems, as well as with hydrocarbon and fuel gas feeds for
production of hydrogen, CO, methane, ethane, ethylene, propane,
propylene, butanes, butenes, pentanes, pentenes, and all of their
derivatives including fuels, solvents, monomers, polymers,
specialty chemicals and large arrays of refined products.
[0149] Now, a calculated example of a process according to one
embodiment will be described. The following embodiment includes a
coal beneficiation plant integrated at a pulverized coal-fired
power plant. For this example, the coal beneficiation plant is
designed to use a North Dakota lignite coal for a nominal 50
tons/hour raw coal capacity. The ultimate and proximate analysis
for the North Dakota Lignite coal is presented in Table 5 (Kitto
& Stultz, 2005).
TABLE-US-00005 TABLE 5 Coal analysis for North Dakota Lignite coal
(Kitto & Stultz, 2005): Original North Dakota Lignite Proximate
(Wt %) Moisture 33.3 VM (Dry) 43.6 FC (Dry) 45.3 Ash (Dry) 11.1
Heating Value (Btu/lb) As Received 7,090 Ultimate (Dry Wt %) C 63.3
H 4.5 N 1 S 1.1 O 19 Ash 11.1
[0150] For the calculated example, a system as shown in FIG. 2
utilizing recirculated gas (e.g., methane) into the pyrolysis
reactor, was used in the calculations. The beneficiation system was
calculated using a low-ranked coal as the solid carbonaceous
material to produce one or more usable products. The low-ranked
coal enters the pulverizer, where its particle size is reduced to
an appropriate size distribution. Air is introduced into the
pulverizer to move the coal within the pulverizer and to remove
some of the moisture from the coal. As an example, the pulverized
coal exiting the pulverizer may have a moisture content of about
29%. To further reduce the moisture content of the coal, the coal
is separated from the pulverizer air and then transferred to the
dryer, such as through a pipe, where the coal is dried by hot air
until its moisture content is about 3%. Thus, air may be passed
through the dryer to dry the coal. The system may be configured to
utilize flue gas from the catalyst regenerator to either directly
or indirectly dry the pulverized coal. The system may be configured
to utilize hot flue gas that is generated by burning fuel to either
directly or indirectly dry the pulverized coal. The coal may be
separated from the gas prior to the coal being transferred to the
pyrolyzer (e.g., the catalytic pyrolysis reactor).
[0151] The coal enters the pyrolyzer, wherein regenerated catalyst
and fresh catalyst are fluidized with the coal with sufficient
residence time for the pyrolysis to reach the desired extent of the
reaction at about 400.degree. C. In one example, 45% of the
volatile matter in the coal is converted to the gaseous product
composition similar to the results in the experimental example
discussed above. All, or nearly all, of the remaining moisture in
the coal is removed in the pyrolysis reactor. All, or nearly all,
of the sulfur in the coal is converted to H.sub.2S, COS, and
SO.sub.2, resulting in the upgraded coal having a significantly
lower sulfur content. A methane loop may be utilized to fluidize
the particles inside the pyrolysis reactor and carry the solids and
gas products out of the reactor. The solid stream is first
separated from the gas stream, and then is further separated into a
predominantly upgraded coal stream and a predominantly spent (e.g.,
deactivated) catalyst stream. The catalyst in the reactor is
deactivated, mainly through coke deposition on the catalyst. A
classifier may be utilized to separate the solid products into an
upgraded coal stream and a stream of spent catalyst.
[0152] The upgraded coal product, which generally is in powder
form, may be transported for further processing to convert the coal
powder into an easily transportable product (such as pellets or
briquettes). The upgraded coal may also be injected into the boiler
for combustion and steam generation purposes. Because of the
quality of the upgraded coal, the upgraded coal burns cleaner and
more efficiently than the original raw coal introduced into the
pulverizer (e.g., the low-ranked coal). The upgraded coal has a
higher heating value, which according to one example is about
11,760 Btu/lb (as compared to 7,090 Btu/lb) and a production rate
of 24.2 tons/hour. The coal properties (which have been calculated)
are presented in Table 6, provided below. In this example, the
upgraded coal retains over 80% of its original heating value while
the majority of the remaining heating value is in the gaseous and
liquid product.
TABLE-US-00006 TABLE 6 Expected coal analysis for the upgraded
coal. Upgraded North Dakota Lignite Proximate (Wt %) Moisture 0.0
VM (Dry) 27.0 FC (Dry) 56.5 Ash (Dry) 16.5 Heating Value (Btu/lb)
As Received 11,760 Ultimate (Dry Wt %) C 65.7 H 4.53 N 1.24 S 0.62
O 11.4 Ash 16.5
[0153] The predominantly spent catalyst stream is transferred to
the regenerator through an inlet, while air is introduced into the
regenerator through a second inlet. In this calculated example, the
spent catalyst has about 5% carbon by weight from the coking. Also,
the solid-solid separation results in the spent catalyst stream
having less than about 3% of the upgraded coal in the spent
catalyst. The air burns the coke off of the spent catalyst at about
600.degree. C. in the regenerator. It is expected that any upgraded
coal entering the regenerator with the spent catalyst will be fully
combusted, leaving only the coal ash and the regenerated catalyst.
The exiting gas stream from the regenerator is a flue gas with
approximately 4% oxygen, a level which promotes nearly complete
combustion of all carbonaceous material entering the regenerator,
including the coke on the spent catalyst. The flue gas has
approximately 20% CO.sub.2 by volume. The gas and solids exit
separately from the regeneration reactor. A small amount of the
regenerated or recycled catalyst stream (e.g., about 3% or less)
may be purged through a purging device that is fluidly connected to
an outlet of the regenerator. The purged catalyst stream prevents
accumulation of coal ash in the catalyst recirculation loop. The
remaining recycled or regenerated catalyst stream may be
transferred to other elements in the system, such as, for example,
the pyrolyzer through a recycled catalyst stream input.
[0154] The pyrolyzer may also be configured to utilize a fresh
amount of catalyst (i.e., non-recycled or regenerated catalyst) to
maintain the desired catalyst-to-coal ratio. The fresh catalyst is
introduced into the pyrolyzer through an inlet, and the amount of
fresh catalyst may be metered or controlled to maintain the
catalyst-to-coal ratio in the pyrolyzer.
[0155] Based on the calculated data presented in FIG. 5, at
400.degree. C., the expected final gaseous and liquid product
streams out of the pyrolysis reactor and downstream separation
units for this 50 ton/hr coal input are:
TABLE-US-00007 Non-condensable Fuel Gas 1,100 lb/hr Butane/LPG 580
lb/hr BTEX 940 lb/hr Higher Hydrocarbons 2,800 lb/hr Solid sulfur
390 lb/hr CO.sub.2 (CCS quality) 9,400 lb/hr Non-condensable gas
800 lb/hr
[0156] Another system may involve flue gas pyrolysis fluidization,
in which all or a portion of the flue gas from the regeneration
reactor may be used to fluidize the pyrolysis reactor. Preferably,
enough flue gas will be used to provide any necessary heat for the
pyrolysis reactor and to help fluidize the coal and catalyst, as
well as the carrier gas for the gaseous product out of the
pyrolysis reactor. With air fed into the regeneration reactor, the
flue gas will consist mainly of a combination of N.sub.2, H.sub.2O,
CO.sub.2, CO, and SO.sub.2. Any one or more of O.sub.2, hydrogen,
CO.sub.2, CO and/or steam could be used in the regeneration of the
catalyst. Alternatively, flue gas from the regenerator may be kept
separate from the pyrolysis reactor.
[0157] In general, CO.sub.2 capture and purification is more
difficult if CO.sub.2 is present in dilute quantities, such as in
the presence of nitrogen gas, and/or in the presence of trace
amounts of oxygen, such as in a flue gas. As such, the required
process equipment for CO.sub.2 capture and purification is larger
when CO.sub.2 is contaminated with nitrogen and oxygen gases. And
many processing systems, (e.g., acid gas recovery systems) cannot
recover CO.sub.2 when it is too dilute. In the systems and
processes, as disclosed herein, a high concentration of
substantially nitrogen-free and oxygen-free CO.sub.2 is produced in
the pyrolysis reactor. Therefore, an acid gas removal system
dedicated only to capturing the CO.sub.2 from the pyrolysis reactor
will have relatively smaller equipment, and more recovery
technology options may be employed by this system, than would
otherwise be the case if the regenerator was air fired and if the
resultant nitrogen and oxygen laden flue gases from the regenerator
were commingled with pyrolysis gases.
[0158] It should be noted that although coal has been discussed as
an example of a carbonaceous material for use as a feedstock in the
systems and the processes described in this application, other
suitable materials can be used in the systems and processes. For
example, other types of coals that may be used as feedstock in the
systems and processes described in this application include but are
not limited to lignite or brown coals, sub-bituminous, bituminous,
anthracite, peat, or any combination thereof. Coal derived liquids
or oils including but not limited to pyrolysis derived oils, oily
coal slurry, coking derived oils, gasification derived oils,
hydrogenation derived oils, or any combination thereof may be used
as feedstock. Tar sands including but not limited to raw tar sands,
tar sand derived liquids, asphalt, bitumen, or any combination
thereof may be used as feedstock. Oil shale including but not
limited to raw oil shale, oil shale derived liquids, kerogen, or
any combination thereof may be used as feedstock. Waste oils
including but not limited to cooking oils, motor oils, etc., as
well as combinations thereof may be used as feedstock. Municipal
waste, such as solid waste or waste water treatment sludge, may be
used as feedstock. Waste plastics, such as recycled plastics, may
be used as feedstock. Biomass including but not limited to
lignocellulosic biomass (e.g., various agricultural residues, wheat
and rice straw, corn stover, forestry residues, saw dust, wood
chips and bark, etc.), lignocellulosic biomass derived oils (e.g.,
pyrolysis derived oils, hydropyrolysis oils, biocrude, etc.),
various lipid containing oils (e.g., plant derived lipid oils,
jatropha, palm, algal derived lipid oils, etc.), and combinations
thereof may be used as feedstock. Petroleum including but not
limited to various petroleum derived oils, crude oil, refinery
derived oil, asphalt, synthetic crude oil, bottom oils, residual
oils, heavy oils, and combinations thereof may be used as
feedstock. Other suitable materials may be used as feedstock as
well. Preferably, the carbonaceous raw material releases volatile
matter when exposed to thermal pyrolyzation conditions (e.g.,
heated to pyrolysis temperatures). Less suitable carbonaceous
materials would include those such as coke, which has been
substantially depleted of volatile matter content. Moreover, any of
the feedstocks mentioned above may be used independently or as a
co-feed (e.g., co-fed feedstock) with one or more other feedstocks,
which may be taken from the feedstocks mentioned above.
[0159] Para. A. A process for upgrading a solid carbonaceous
material, comprising: heating the solid carbonaceous material in
the presence of a catalyst under partial pyrolysis conditions, and
obtaining an upgraded solid carbonaceous product, a gaseous
product, and a spent catalyst.
[0160] Para. B. The process of Para. A, wherein the solid
carbonaceous material is coal and the upgraded solid carbonaceous
product is an upgraded coal product.
[0161] Para. C. The process of Para. A or B, wherein a weight of
fixed carbon retained in the upgraded solid carbonaceous product is
at least 50 weight percent of fixed carbon in the solid
carbonaceous material.
[0162] Para. D. The process of any one of Paras. A-C, wherein a
weight of ash retained in the upgraded solid carbonaceous product
is at least 60 weight percent of ash in the solid carbonaceous
material.
[0163] Para. E. The process of any one of Para. A-D, wherein a
weight of volatile matter retained in the upgraded solid
carbonaceous product is from about 10 to about 90 weight percent of
volatile matter in the solid carbonaceous material.
[0164] Para. F. The process of any one of Para. A-E, wherein a
weight of volatile matter retained in the upgraded coal product is
from about 10 to about 90 weight percent of volatile matter in the
coal.
[0165] Para. G. The process of any one of Para. A-F, further
comprising pretreating the starting solid carbonaceous material
prior to heating under partial pyrolysis conditions using at least
one of a dryer, a de-asher, and a washer.
[0166] Para. H. The process of any one of Para. A-G, further
comprising obtaining an amount of CO.sub.2 greater than about 10
weight % of the volatile matter in the starting solid carbonaceous
material.
[0167] Para. I. The process of any one of Para. A-H, further
comprising separating the gaseous product from the upgraded solid
carbonaceous product.
[0168] Para. J. The process of any one of Para. I, further
comprising condensing the separated gaseous product into a gaseous
stream and a liquid stream.
[0169] Para. K, The process of any one of Para. A-J, further
comprising obtaining an amount of a non-condensable fuel gas from
about 1 to about 40 weight % of the volatile matter in the starting
solid carbonaceous material.
[0170] Para. L. The process of any one of Para. A-K, further
comprising obtaining an amount of a non-condensable fuel gas from
about 1 to about 40 weight % of the volatile matter in the starting
coal.
[0171] Para. M. The process of any one of Para. A-L, further
comprising obtaining an amount of LPG greater than from about 1 to
about 40 weight % of the volatile matter in the starting solid
carbonaceous material.
[0172] Para. N. The process of any one of Para. A-M, further
comprising obtaining an amount of BTEX from about 0.5 to about 40
weight % of the volatile matter in the starting solid carbonaceous
material.
[0173] Para. O. The process of any one of Para. A-N, further
comprising obtaining an amount of Higher Hydrocarbons from about
0.3 to about 20 weight % of the volatile matter in the starting
solid carbonaceous material.
[0174] Para. P. The process of any one of Para. A-O, further
comprising obtaining an amount of heteroatom-containing organics
that is no greater than 5 weight % of the volatile matter in the
starting solid carbonaceous material.
[0175] Para. Q. The process of any one of Para. A-P, wherein the
spent catalyst and the upgraded solid carbonaceous product are
recovered as a mixture.
[0176] Para. R. The process of any one of Para. A-Q, wherein the
spent catalyst and the upgraded solid carbonaceous product are
recovered separately.
[0177] Para. S. The process of any one of Para. A-R, further
comprising regenerating the spent catalyst by contacting the spent
catalyst with a mixture of gases containing at least one oxidizing
gas to form a regenerated catalyst.
[0178] Para. T. The process of any one of Para. S, wherein at least
a portion of the regenerated catalyst is heated in the presence of
additional solid carbonaceous material in a subsequent partial
pyrolysis reaction.
[0179] Para. U. The process of any one of Para. A-T, further
comprising regenerating the spent catalyst by acid washing the
spent catalyst with an acidic solution to form a regenerated
catalyst.
[0180] Para. V. The process of any one of Para. S-U, wherein at
least a portion of the regenerated catalyst is heated in the
presence of additional solid carbonaceous material in a sub sequent
partial pyrolysi s reaction.
[0181] Para. W. The process of Para. A-V, wherein a weight of total
sulfur retained in the upgraded solid carbonaceous product is no
more than 80 weight percent of the total sulfur in the starting
solid carbonaceous material.
[0182] Para. X. The process of any one of Para. A-V, wherein a
weight of organic sulfur retained in the upgraded solid
carbonaceous product is no more than 50 weight percent of the
organic sulfur in the starting solid carbonaceous material.
[0183] Para. AA. A process for converting a solid carbonaceous
material in a beneficiation system into a upgraded solid
carbonaceous product, the process comprising: [0184] introducing
the solid carbonaceous material and a catalyst into a pyrolysis
reactor to produce a gaseous product stream and a solid product
stream, wherein the solid product stream comprises the upgraded
solid carbonaceous product; [0185] recovering the gaseous product
stream from the reactor; and [0186] recovering the solid product
stream from the reactor.
[0187] Para. AB. The process of Para. AA, wherein the solid
carbonaceous material is coal and the upgraded solid carbonaceous
product is an upgraded coal product.
[0188] Para. AC. The process of any one of Para. AA-AB, wherein the
catalyst is immobilized in the pyrolysis reactor; and the process
further comprises separating the upgraded solid carbonaceous
product from the catalyst inside the pyrolysis reactor.
[0189] Para. AD. The process of any one of Para. AA-AC, further
comprising: [0190] recovering a separated spent catalyst from the
pyrolysis reactor; [0191] transferring the spent catalyst to a
regenerator; and [0192] regenerating the spent catalyst in the
regenerator, in which unpyrolyzed coal, coke, and carbonaceous
material are removed from the spent catalyst.
[0193] Para. AE. The process of any one of Para. AA-AD, further
comprising: [0194] transferring the gaseous product stream to a
separator; and [0195] at least partially condensing the gaseous
product stream in the separator [0196] producing a refined gas
stream, a hydrocarbon liquid stream, and an aqueous liquid phase
stream.
[0197] Para. AF. The process of any one of Para. AA-AE, wherein the
solid product stream further comprises a spent catalyst, the
process further comprising: [0198] separating the solid product
stream into the upgraded solid carbonaceous product and the spent
catalyst after recovering the solid product stream from the
pyrolysis reactor, wherein the separated spent catalyst comprises
the catalyst and at least one of unpyrolyzed coal, coke, and
carbonaceous material.
[0199] Para. AG. The process of Para. AF, further comprising:
[0200] transferring the separated catalyst to a regenerator in
which at least a portion of the at least one of the unpyrolyzed
coal, coke, and carbonaceous material is removed from the catalyst;
and [0201] transferring the gaseous product stream to a separator
in which the gaseous product stream is at least partially condensed
in the separator producing a refined gas stream, a hydrocarbon
liquid stream, and an aqueous liquid phase stream.
[0202] Para. AH. The process of any one of Para. AA-AG, wherein at
least a portion of the at least one of the unpyrolyzed coal, coke,
and carbonaceous material is removed from the catalyst by at least
one of combustion, steam, and a reducing gas.
[0203] Para. AI. The process of any one of Para. AA-AH, wherein the
pyrolysis reactor is configured as one of a HERB, a fluidized bed,
a moving bed, or an entrained flow bed, and wherein the coal and
the catalyst move through the pyrolysis reactor.
[0204] Para. AJ. The process of any one of Para. AA-AI, wherein the
solid product stream is transferred outside the pyrolysis reactor
to a solid-solid separator that separates the upgraded solid
carbonaceous product and the spent catalyst.
[0205] Para. AK. The process of any one of Para. AA-AJ, wherein the
solid-solid separator includes a classifier that separates the
upgraded solid carbonaceous product from the spent catalyst based
on one of particle size, mass, or density.
[0206] Para. AL. The process of any one of Para. AA-AK, wherein at
least one of a size and a density of the spent catalyst is
different than at least one of a size and a density of the upgraded
solid carbonaceous product, and wherein the classifier of the
solid-solid separator separates the upgraded solid carbonaceous
product and the spent catalyst based on at least one of size and
density.
[0207] Para. AM. The process of any one of Para. AA-AL, further
comprising: [0208] reducing a size of the particles of the solid
carbonaceous material in a pulverizer prior to being introduced
into the pyrolysis reactor; and [0209] pretreating the solid
carbonaceous material in a pretreating device that includes at
least one of a dryer configured to dry the coal from the pulverizer
utilizing a stream of heated fluid, a washer configured to wash the
coal from the pulverizer, and a de-asher configured to remove ash
from the coal, wherein the pretreating device is provided between
the pulverizer and the pyrolysis reactor.
[0210] Para. AN. The process of any one of Para. AM, wherein the
stream of heated fluid is hot flue gas produced by a regenerator
during removal of at least a portion of any unpyrolyzed coal, coke,
and carbonaceous material from the spent catalyst utilizing an
oxygen-carrying gas.
[0211] Para. AO. The process of any one of Para. AE-AN, wherein the
separator further includes an acid gas removal system that
separates at least one of a sulfur-carrying compound, a
nitrogen-carrying compound, and carbon dioxide from the gaseous
product stream.
[0212] Para. AP. The process of any one of Para. AA-AO, wherein the
catalyst introduced into the pyrolysis reactor includes a first
portion comprising regenerated catalyst received from a regenerator
and a second portion comprising new catalyst that has not been
regenerated, and wherein the first portion of regenerated catalyst
has a higher relative temperature than the new catalyst and the
coal, such that the regenerated catalyst is a heating medium to
heat the coal introduced into the pyrolysis reactor.
[0213] Para. AQ. The process of any one of Para. AA-AP, wherein the
catalytic pyrolysis of the solid carbonaceous material takes place
at a temperature from about 350.degree. C. to about 850.degree.
C.
[0214] Para. AR. The process of any one of Para. AA-AQ, wherein the
solid carbonaceous material introduced into the pyrolysis reactor
has a weighted hour space velocity from about 0.2 to about 25 kg/hr
per kg of catalyst.
[0215] Para. AS. The process of any one of Para. AA-AR, wherein the
solid carbonaceous material has a residence time during the
catalytic process from about 0.1 second to about 1 minute.
[0216] Para. AT. The process of any one of Para. AA-AS, wherein a
weight ratio of the catalyst to solid carbonaceous material
introduced into the pyrolysis reactor is from about 0 to about
100.
[0217] Para. AU. The process of any one of Para. AA-AS, further
comprising: [0218] providing an acid gas removal system that is
configured to capture and isolating CO.sub.2 from at least one of
the gaseous product from the pyrolysis reactor and a gas from a
regenerator configured to regenerate spent catalyst from the
pyrolysis reactor; and [0219] obtaining an amount of CO.sub.2
greater than about 4 weight % of the dry ash free coal.
[0220] Para. AV. The process of any one of Para. AA-AU, further
comprising obtaining an amount of CO.sub.2 greater than about 10
weight % of the volatile matter in the starting solid carbonaceous
material.
[0221] Para. AW. The process of any one of Para. AA-AV, further
comprising obtaining an amount of CO.sub.2 greater than about 4
weight % of the dry ash free coal.
[0222] Para. AX. The process of any one of Para. AA-AW, further
comprising: [0223] regenerating a spent catalyst in a regenerator
configured to produce a hot flue gas during regeneration; and
[0224] transferring at least a portion of the hot flue gas to the
pyrolysis reactor to fluidize the pyrolysis reactor.
[0225] Para. AY. The process of any one of Para. AX, wherein a
gaseous fluid comprising at least one of CO, CO.sub.2, water,
hydrogen, and oxygen is introduced into the regenerator to
facilitate removal of unpyrolyzed coal, coke, and carbonaceous
material from the spent catalyst.
[0226] Para. AZ. The process of any one of Para. AY, further
comprising collecting the hot flue gas that includes CO.sub.2 for
one of carbon sequestration or enhanced oil recovery.
[0227] Para. BA. The process of any one of Para. AX-AZ, further
comprising passing the hot flue gas through a heat exchanger to
produce heat that is used to heat the solid carbonaceous material
in the pyrolysis reactor.
[0228] Para. BB. The process of any one of Para. AX-BA, wherein the
regenerator uses steam in addition to, or instead of, air to remove
the coal, coke, and carbonaceous material from the spent catalyst
by at least one of hydrolysis and steam gasification.
[0229] Para. BC. The process of any one of Para. AX-BB, wherein the
regenerator uses hydrogen or at least one other hydrogen-containing
chemical, including hydrocarbons, to reductively remove the coal,
coke, and carbonaceous material from the spent catalyst.
[0230] Para. BD. The process of any one of Para. AA-BC, wherein a
gas is co-fed into the pyrolysis reactor, wherein the gas comprises
at least one light hydrocarbon compound that is recovered from the
gaseous product stream.
[0231] Para. BE. The process of any one of Para. AA-BD, wherein the
at least one light hydrocarbon compound is recycled back to the
pyrolysis reactor.
[0232] Para. BF. The process of any one of Para. AA-BE, further
comprising obtaining an amount of BTEX from about 0.5 to about 80
weight % of the volatile matter in the starting solid carbonaceous
material.
[0233] Para. BG. The process of any one of Para. AA-BF, wherein a
biomass is co-fed into the pyrolysis reactor.
[0234] Para. BH. The process of any one of Para. AA-BG, wherein at
least one of an oil shale, a coal derived liquid, a tar sand, and a
petroleum is co-fed into the pyrolysis reactor.
[0235] Para. BI. The process of any one of Para. AA-BH, wherein at
least one of a wet gas and a natural gas is co-fed into the
pyrolysis reactor.
[0236] Para. BJ. The process of any one of Para. AA-BI, wherein the
pyrolysis reactor includes a stationary catalyst, such that the
solid carbonaceous material moves relative to the catalyst through
the reactor, to produce the gaseous product stream and the solid
product stream, the process further comprising: [0237] transferring
the gaseous product stream to a separator to at least partially
condense at least a portion of the gas product stream into a liquid
product and a gaseous product; and [0238] wherein the solid product
stream contains less than 1 weight part catalyst per 100 parts
upgraded carbonaceous product.
[0239] Para. CA. A process for converting a biomass in a
beneficiation system into an upgraded solid product, the process
comprising: [0240] introducing the biomass and a catalyst into a
pyrolysis reactor to produce a gaseous product stream and an
upgraded solid product stream, the solid product stream comprising
spent catalyst and the upgraded solid product; [0241] separating
the upgraded solid product and the spent catalyst; [0242]
transferring the separated spent catalyst to a regenerator that
removes at least a portion of any unpyrolyzed coal, coke, and other
carbonaceous material from the spent catalyst; and [0243]
transferring the gaseous product stream to a separator that
produces a liquid product and a gaseous product; [0244] wherein a
weight of ash retained in the upgraded solid product is at least 60
weight percent of ash in the biomass introduced into the pyrolysis
reactor.
[0245] Para. CB. The process of Para. CA, wherein an amount of
phenol produced is less than an amount of toluene produced on a
weight basis.
[0246] Para. CC. The process of Para. CA or CB, wherein an amount
of tars produced is less than an amount of light oils produced on a
weight basis.
[0247] As utilized herein, the terms "approximately," "about,"
"substantially", and similar terms are intended to have a broad
meaning in harmony with the common and accepted usage by those of
ordinary skill in the art to which the subject matter of this
disclosure pertains. It should be understood by those of skill in
the art who review this disclosure that these terms are intended to
allow a description of certain features described and claimed
without restricting the scope of these features to the precise
numerical ranges provided. Accordingly, these terms should be
interpreted as indicating that insubstantial or inconsequential
modifications or alterations of the subject matter described and
claimed are considered to be within the scope of the invention as
recited in the appended claims.
[0248] The terms "coupled," "connected," and the like, as used
herein, mean the joining of two members directly or indirectly to
one another. Such joining may be stationary (e.g., permanent) or
moveable (e.g., removable or releasable). Such joining may be
achieved with the two members or the two members and any additional
intermediate members being integrally formed as a single unitary
body with one another or with the two members or the two members
and any additional intermediate members being attached to one
another.
[0249] References herein to the positions of elements (e.g., "top,"
"bottom," "above," "below," etc.) are merely used to describe the
orientation of various elements in the FIGURES. It should be noted
that the orientation of various elements may differ according to
other illustrative embodiments, and that such variations are
intended to be encompassed by the present disclosure.
[0250] The construction and arrangement of the elements of the
systems (e.g., beneficiation systems) as shown in the illustrative
embodiments are illustrative only. Although only a few embodiments
of the present disclosure have been described in detail, those
skilled in the art who review this disclosure will readily
appreciate that many modifications are possible (e.g., variations
in sizes, dimensions, structures, shapes and proportions of the
various elements, values of parameters, mounting arrangements, use
of materials, colors, orientations, etc.) without materially
departing from the novel teachings and advantages of the subject
matter recited. For example, elements shown as integrally formed
may be constructed of multiple parts or elements, the position of
elements may be reversed or otherwise varied, and the nature or
number of discrete elements or positions may be altered or
varied.
[0251] Additionally, the word "illustrative" is used to mean
serving as an example, instance, or illustration. Any embodiment or
design described herein as "illustrative" is not necessarily to be
construed as preferred or advantageous over other embodiments or
designs (and such term is not intended to connote that such
embodiments are necessarily extraordinary or superlative examples).
Rather, use of the word "illustrative" is intended to present
concepts in a concrete manner. Accordingly, all such modifications
are intended to be included within the scope of the present
disclosure. Other substitutions, modifications, changes, and
omissions may be made in the design, operating conditions, and
arrangement of the preferred and other illustrative embodiments
without departing from the scope of the appended claims.
[0252] As used herein, "about" will be understood by persons of
ordinary skill in the art and will vary to some extent depending
upon the context in which it is used. If there are uses of the term
which are not clear to persons of ordinary skill in the art, given
the context in which it is used, "about" will mean up to plus or
minus 10% of the particular term.
[0253] The use of the terms "a" and "an" and "the" and similar
referents in the context of describing the elements (especially in
the context of the following claims) are to be construed to cover
both the singular and the plural, unless otherwise indicated herein
or clearly contradicted by context. Recitation of ranges of values
herein are merely intended to serve as a shorthand method of
referring individually to each separate value falling within the
range, unless otherwise indicated herein, and each separate value
is incorporated into the specification as if it were individually
recited herein. All methods described herein can be performed in
any suitable order unless otherwise indicated herein or otherwise
clearly contradicted by context. The use of any and all examples,
or exemplary language (e.g., "such as") provided herein, is
intended merely to better illuminate the embodiments and does not
pose a limitation on the scope of the claims unless otherwise
stated. No language in the specification should be construed as
indicating any non-claimed element as essential.
[0254] While certain embodiments have been illustrated and
described, it should be understood that changes and modifications
can be made therein in accordance with ordinary skill in the art
without departing from the technology in its broader aspects as
defined in the following claims.
[0255] The embodiments, illustratively described herein may
suitably be practiced in the absence of any element or elements,
limitation or limitations, not specifically disclosed herein. Thus,
for example, the terms "comprising," "including," "containing,"
etc. shall be read expansively and without limitation.
Additionally, the terms and expressions employed herein have been
used as terms of description and not of limitation, and there is no
intention in the use of such terms and expressions of excluding any
equivalents of the features shown and described or portions
thereof, but it is recognized that various modifications are
possible within the scope of the claimed technology. Additionally,
the phrase "consisting essentially of" will be understood to
include those elements specifically recited and those additional
elements that do not materially affect the basic and novel
characteristics of the claimed technology. The phrase "consisting
of" excludes any element not specified.
[0256] The present disclosure is not to be limited in terms of the
particular embodiments described in this application. Many
modifications and variations can be made without departing from its
spirit and scope, as will be apparent to those skilled in the art.
Functionally equivalent methods and compositions within the scope
of the disclosure, in addition to those enumerated herein, will be
apparent to those skilled in the art from the foregoing
descriptions. Such modifications and variations are intended to
fall within the scope of the appended claims. The present
disclosure is to be limited only by the terms of the appended
claims, along with the full scope of equivalents to which such
claims are entitled. It is to be understood that this disclosure is
not limited to particular methods, reagents, compounds compositions
or biological systems, which can of course vary. It is also to be
understood that the terminology used herein is for the purpose of
describing particular embodiments only, and is not intended to be
limiting.
[0257] As will be understood by one skilled in the art, for any and
all purposes, particularly in terms of providing a written
description, all ranges disclosed herein also encompass any and all
possible subranges and combinations of subranges thereof. Any
listed range can be easily recognized as sufficiently describing
and enabling the same range being broken down into at least equal
halves, thirds, quarters, fifths, tenths, etc. As a non-limiting
example, each range discussed herein can be readily broken down
into a lower third, middle third and upper third, etc. As will also
be understood by one skilled in the art all language such as "up
to," "at least," "greater than," "less than," and the like, include
the number recited and refer to ranges which can be subsequently
broken down into subranges as discussed above. Finally, as will be
understood by one skilled in the art, a range includes each
individual member.
[0258] All publications, patent applications, issued patents, and
other documents referred to in this specification are herein
incorporated by reference as if each individual publication, patent
application, issued patent, or other document was specifically and
individually indicated to be incorporated by reference in its
entirety. Definitions that are contained in text incorporated by
reference are excluded to the extent that they contradict
definitions in this disclosure.
[0259] Other substitutions, modifications, changes and omissions
may also be made in the design, operating conditions and
arrangement of the various illustrative embodiments without
departing from the scope of the present invention. For example, any
element disclosed in one embodiment may be incorporated or utilized
with any other embodiment disclosed herein. Also, for example, the
order or sequence of any process or method steps may be varied or
re-sequenced according to alternative embodiments. Any
means-plus-function clause is intended to cover the structures
described herein as performing the recited function and not only
structural equivalents but also equivalent structures. Other
substitutions, modifications, changes and omissions may be made in
the design, operating configuration, and arrangement of the
preferred and other illustrative embodiments without departing from
the scope of the appended claims.
* * * * *