U.S. patent application number 14/748964 was filed with the patent office on 2015-10-15 for biomass high efficiency hydrothermal reformer.
The applicant listed for this patent is RES USA LLC.. Invention is credited to Randy BLEVINS, Joshua B. Pearson, Harold A. Wright.
Application Number | 20150291897 14/748964 |
Document ID | / |
Family ID | 46126815 |
Filed Date | 2015-10-15 |
United States Patent
Application |
20150291897 |
Kind Code |
A1 |
BLEVINS; Randy ; et
al. |
October 15, 2015 |
BIOMASS HIGH EFFICIENCY HYDROTHERMAL REFORMER
Abstract
A system for the production of synthesis gas, the system
including a mixing apparatus configured for combining steam with at
least one carbonaceous material to produce a reformer feedstock;
and a reformer comprising a cylindrical vessel containing a
plurality of coiled tubes, each of the plurality of coiled tubes
having a vertical height in the range of from about 40 feet 12.2 m)
to about 100 feet (30.5 m) and a coil length that is at least four
times the vertical height; at least one burner configured to
combust a fuel and provide heat to maintain the reformer at a
reformer temperature; at least one outlet for reformer product
comprising synthesis gas; and at least one outlet for flue gas
produced via combustion of fuel in the burners. A suitable mixing
apparatus is also provided.
Inventors: |
BLEVINS; Randy; (West Des
Moines, IA) ; Pearson; Joshua B.; (Lakewood, CO)
; Wright; Harold A.; (Longmont, CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
RES USA LLC. |
Westminster |
CO |
US |
|
|
Family ID: |
46126815 |
Appl. No.: |
14/748964 |
Filed: |
June 24, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13111836 |
May 19, 2011 |
|
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|
14748964 |
|
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Current U.S.
Class: |
422/162 |
Current CPC
Class: |
B01J 19/243 20130101;
B01J 19/2425 20130101; B01J 8/067 20130101; C10J 2300/0916
20130101; Y02P 20/145 20151101; C01B 3/02 20130101; F23G 5/444
20130101; Y02E 50/32 20130101; B01J 2219/00006 20130101; B01J
2208/00309 20130101; C10J 3/485 20130101; C01B 3/346 20130101; C01B
2203/0811 20130101; B01J 2219/00157 20130101; C01B 2203/1241
20130101; C10J 3/466 20130101; C10J 2300/0909 20130101; C10J
2200/09 20130101; Y02P 30/30 20151101; B01J 19/2415 20130101; B01J
2219/24 20130101; F23G 5/04 20130101; B01J 2219/00159 20130101;
F23G 5/033 20130101; C10G 2/34 20130101; C10J 2300/0976 20130101;
C10G 2/30 20130101; C10J 2300/1223 20130101; C10J 2300/0906
20130101; C10J 2300/1853 20130101; B01J 2208/00504 20130101; Y02E
50/30 20130101; Y02P 30/00 20151101; C01B 2203/0216 20130101; C10J
2300/1659 20130101; C10J 3/30 20130101; C10J 3/80 20130101; C10J
2300/1687 20130101; B01J 19/242 20130101; C10J 2300/1246
20130101 |
International
Class: |
C10J 3/48 20060101
C10J003/48; B01J 19/24 20060101 B01J019/24; C01B 3/34 20060101
C01B003/34; C10G 2/00 20060101 C10G002/00 |
Claims
1. A system for the production of synthesis gas, the system
comprising: a mixing apparatus configured for combining steam with
at least one carbonaceous material to produce a reformer feedstock;
and a reformer comprising: a cylindrical vessel containing a
plurality of coiled tubes, wherein each of the plurality of coiled
tubes has a vertical height in the range of from about 40 feet 12.2
m) to about 100 feet (30.5 m) and a coil length that is at least
four times the vertical height; at least one burner configured to
combust a fuel and provide heat to maintain the reformer at a
reformer temperature; at least one outlet for reformer product
comprising synthesis gas; and at least one outlet for flue gas
produced via combustion of fuel in the at least one burner.
2. The system of claim 1 wherein at least a portion of the coiled
tubes have an inside diameter of at least 2 inches (5.1 cm).
3. The system of claim 1 wherein each of the plurality of coiled
tubes has a coil length that is in the range of from about 400 feet
(121.9 m) to about 1000 feet (304.8 m).
4. The system of claim 1 wherein the reformer is configured to
provide a residence time in the range of from about 0.3 s to about
3 s.
5. The system of claim 1 wherein the metallurgy of the coiled tubes
allows operation at a reformer temperature above 1700.degree. F.
(927.degree. C.).
6. The system of claim 1 wherein the metallurgy of the coiled tubes
allows operation at a reformer temperature in the range of from
about 1700.degree. F. (927.degree. C.) to about 2200.degree. F.
(1204.degree. C.).
7. The system of claim 1 wherein the reformer is operable at a
reformer pressure of greater than or equal to about 45 psig.
8. The system of claim 1 wherein the mixing apparatus and the
reformer are fluidly connected via one or more mixing apparatus
outlet lines and a distributor configured to provide reformer
feedstock to each of the plurality of coiled tubes.
9. The system of claim 1 wherein the at least one burner is
positioned at, near, or below the bottom of the cylindrical
vessel.
10. The system of claim 1 wherein the at least one burner is
configured to burn a fuel comprising Fischer-Tropsch tailgas,
synthesis gas, methane, or a combination of any two or more
thereof.
11. The system of claim 1 further comprising Fischer-Tropsch
synthesis apparatus downstream of the reformer, and configured to
produce Fischer-Tropsch hydrocarbons and Fischer-Tropsch
tailgas.
12. The system of claim 11 wherein the Fischer-Tropsch synthesis
apparatus comprises a slurry Fischer-Tropsch reactor.
13. The system of claim 1 wherein the mixing apparatus comprises
one or more cylindrical mixing vessels having a conical bottom and
having an inlet for superheated steam connected with the conical
bottom and an inlet for at least one carbonaceous material at or
near the top of the cylindrical vessel.
14. The system of claim 1 wherein the mixing apparatus is
constructed of suitable material for operation at a pressure of
greater than or equal to about 45 psig.
15. The system of claim 1 wherein the outlets of each of the
plurality of coiled tubes are manifolded via an outlet manifold
into the at least one outlet for reformer product comprising
synthesis gas.
16. The system of claim 15 wherein the outlet manifold is
positioned at, near, or below the bottom of the cylindrical
vessel.
17. The system of claim 1 wherein the at least one outlet for flue
gas is positioned at or near the top of the cylindrical vessel.
18. The system of claim 1 further comprising a steam superheater
configured to utilize the heat of the flue gas formed in the
reformer to produce superheated steam.
19. The system of claim 1 further comprising feed preparation
apparatus configured to comminute the at least one carbonaceous
material, to dry the at least one carbonaceous material, or
both.
20. The system of claim 19 wherein the feed preparation apparatus
comprises at least one grinder and at least one separator
configured to provide a carbonaceous material having an average
particle diameter of less than about 3/16.sup.th of an inch (0.47
cm).
21. The system of claim 19 wherein the feed production apparatus is
configured to provide a carbonaceous material having a moisture
content of less than about 20 weight percent.
22. The system of claim 1 wherein the mixing apparatus for
combining steam with at least one carbonaceous material to produce
a reformer feedstock comprises: at least one mixing vessel
comprising: a cylindrical vessel with a conical bottom; a steam
inlet configured for introducing steam into the conical bottom; a
carbonaceous material inlet configured for introducing a
carbonaceous feed into the cylindrical vessel; and an outlet for a
reformer feedstock comprising at least 0.3 pounds of steam per
pound of carbonaceous material, wherein the at least one mixing
vessel is configured for operation at a pressure of greater than
about 10 psig.
23. The system of claim 1 wherein the reformer is an anaerobic
reformer.
24. The system of claim 23 further comprising a source of biomass
as carbonaceous material.
25. The system of claim 1 wherein the reformer provides synthesis
gas having a molar ratio of hydrogen to carbon monoxide in the
range of from about 0.7:1 to about 1:1.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/111,836, filed May 19, 2011, the disclosure
of which is hereby incorporated herein by reference in its entirety
for all purposes.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND
[0003] 1. Field of the Invention
[0004] This disclosure relates generally to the conversion of
carbonaceous feedstock into synthesis gas. More specifically, this
disclosure relates to a reforming apparatus for the conversion of
carbonaceous feedstock to synthesis gas. Still more specifically,
this disclosure relates to a high temperature, high efficiency
reformer configured for production of synthesis gas from a reformer
feedstock comprising at least one carbonaceous material.
[0005] 2. Background of the Invention
[0006] Processes for the production of synthesis gas from
carbonaceous materials utilize gasification of a feedstock
comprising the carbonaceous materials in a so-called `reformer` to
produce a stream comprising synthesis gas (i.e. hydrogen and carbon
monoxide; also known as `syngas`). The product synthesis gas
generally also comprises amounts of carbon dioxide and methane and
may also comprise minor amounts of other components. Generation of
synthesis gas is disclosed in numerous patents.
[0007] Synthesis gas produced via gasification of carbonaceous
materials can be converted into other compounds in a so-called
Fischer-Tropsch reaction. Fischer-Tropsch (FT) synthesis can be
used to catalytically produce synthetic liquid fuels, alcohols or
other oxidized compounds. FT synthesis occurs by the metal
catalysis of an exothermic reaction of synthesis gas.
Fischer-Tropsch (FT) technology can thus be utilized to convert
synthesis gas to valuable products. Hydrocarbon liquid products of
various Fischer-Tropsch processes are generally refined to produce
a range of synthetic fuels, lubricants and waxes. Often, the
Fischer-Tropsch process is performed in a slurry bubble column
reactor (SBCR). The technology of converting synthesis gas
originating from natural gas into valuable primarily liquid
hydrocarbon products is referred to as Gas To Liquids (GTL)
technology. When coal is the raw material for the syngas, the
technology is commonly referred to as Coal-To-Liquids (CTL).
Fischer-Tropsch technology is one of several conversion techniques
included in the broader GTL/CTL technology. Desirably, the
synthesis gas for subsequent production of valuable products via
Fischer-Tropsch is produced from `green` materials. For example, an
environmentally-friendly system for the production of synthesis
gas, which may subsequently be utilized to produce Fischer-Tropsch
products, would desirably allow for the production of synthesis gas
from carbonaceous materials, such as biomass, which may generally
be considered waste materials
[0008] The catalyst used in the reactor and to some extent the
temperatures and pressures used, will determine what products can
be obtained. Some Fischer-Tropsch processes are directed to the
production of liquid hydrocarbons. Other Fischer-Tropsch processes
are directed toward the production of alcohols. Depending on the
subsequent downstream application for which the synthesis gas is
produced, the reformer can be operated to provide synthesis gas
having a desired molar ratio of hydrogen to carbon monoxide.
[0009] Accordingly, there is a need in the art for systems and
methods for the production of synthesis gas from carbonaceous
materials. Such systems and methods should preferably enable the
environmentally-friendly production of synthesis gas, for example
by allowing the use of sustainable and renewable feedstocks such as
biomass, facilitating sequestration of carbon dioxide and/or
reducing the amount of waste material produced.
SUMMARY
[0010] Herein disclosed is a system for the production of synthesis
gas, the system comprising: a mixing apparatus configured for
combining steam with at least one carbonaceous material to produce
a reformer feedstock; and a reformer comprising: a cylindrical
vessel containing a plurality of coiled tubes, wherein each of the
plurality of coiled tubes has a vertical height in the range of
from about 40 feet 12.2 m) to about 100 feet (30.5 m) and a coil
length that is at least four times the vertical height; at least
one burner configured to combust a fuel and provide heat to
maintain the reformer at a reformer temperature; at least one
outlet for reformer product comprising synthesis gas; and at least
one outlet for flue gas produced via combustion of fuel in the
burners.
[0011] In embodiments, at least a portion of the coiled tubes have
an inside diameter of at least 2 inches (5.1 cm). In embodiments,
each of the plurality of coiled tubes has a coil length that is in
the range of from about 400 feet (121.9 m) to about 1000 feet
(304.8 m). In embodiments, the reformer is configured to provide a
residence time in the range of from about 0.3 s to about 3 s. In
embodiments, the metallurgy of the coiled tubes allows operation at
a reformer temperature above 1700.degree. F. (927.degree. C.). In
embodiments, the metallurgy of the coiled tubes allows operation at
a reformer temperature in the range of from about 1700.degree. F.
(927.degree. C.) to about 2200.degree. F. (1204.degree. C.). In
embodiments, the reformer is operable at a reformer pressure of
greater than or equal to about 45 psig. In embodiments, the mixing
apparatus and the reformer are fluidly connected via one or more
mixing apparatus outlet lines and a distributor configured to
provide reformer feedstock to each of the plurality of coiled
tubes. In embodiments, the at least one burner is positioned at,
near, or below the bottom of the cylindrical vessel. In
embodiments, the at least one burner is configured to burn a fuel
comprising Fischer-Tropsch tailgas, synthesis gas, methane, or a
combination of two or more thereof. In embodiments, the mixing
apparatus comprises one or more cylindrical mixing vessels having a
conical bottom and having an inlet for superheated steam connected
with the conical bottom and an inlet for at least one carbonaceous
material at or near the top of the cylindrical vessel. In
embodiments, the mixing apparatus is constructed of suitable
material for operation at a pressure of greater than or equal to
about 45 psig. In embodiments, the outlets of each of the plurality
of coiled tubes are manifolded via an outlet manifold into the at
least one outlet for reformer product comprising synthesis gas. The
outlet manifold may be positioned at, near, or below the bottom of
the cylindrical vessel. In embodiments, the at least one outlet for
flue gas is positioned at or near the top of the cylindrical
vessel. In embodiments, the system further comprises a steam
superheater configured to utilize the heat of the flue gas formed
in the reformer to produce superheated steam.
[0012] In embodiments, the system further comprises feed
preparation apparatus configured to comminute the at least one
carbonaceous material, to dry the at least one carbonaceous
material, or both. In embodiments, the feed preparation apparatus
comprises at least one grinder and at least one separator
configured to provide a carbonaceous material having an average
particle diameter of less than about 3/16.sup.th of an inch (0.47
cm). In embodiments, the feed production apparatus is configured to
provide a carbonaceous material having a moisture content of less
than about 20 weight percent.
[0013] Also disclosed herein is a mixing apparatus configured for
producing a reformer feedstock, the mixing vessel comprising: at
least one mixing vessel comprising: a cylindrical vessel with a
conical bottom; a steam inlet configured for introducing steam into
the conical bottom; a carbonaceous material inlet configured for
introducing a carbonaceous feed into the cylindrical vessel; and an
outlet for a reformer feedstock comprising at least 0.3 pounds of
steam per pound of carbonaceous material, wherein the at least one
mixing vessel is configured for operation at a pressure of greater
than about 10 psig.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] For a more detailed description of the preferred embodiment
of the present invention, reference will now be made to the
accompanying drawings, wherein:
[0015] FIG. 1 is a schematic of a synthesis gas production system
according to an embodiment of this disclosure, the production
system or biorefinery comprising a high efficiency, hydrothermal
reformer and suitable for carrying out the production of synthesis
gas conversion products;
[0016] FIG. 2 is a schematic of a synthesis gas production system
according to another embodiment of this disclosure;
[0017] FIG. 3 is a schematic of a synthesis gas production system
according to another embodiment of this disclosure;
[0018] FIG. 4 is schematic of a feedstock handling and/or drying
apparatus according to an embodiment of this disclosure; and
[0019] FIG. 5 is a flow diagram of a method of producing synthesis
gas according to an embodiment of this disclosure.
NOTATION AND NOMENCLATURE
[0020] Certain terms are used throughout the following description
and claims to refer to particular system components. This document
does not intend to distinguish between components that differ in
name but not function.
[0021] As used herein, the term `carbonaceous feedstock` includes
not only organic matter that is part of the stable carbon cycle,
but also fossilized organic matter such as coal, petroleum, and
natural gas, and products, derivatives and byproducts thereof such
as plastics, petroleum coke and the like.
[0022] As used herein, the terms `hot`, `warm`, `cool` and `cold`
are utilized to refer to the relative condition of various streams.
That is, a `hot` stream is at a higher temperature than a `warm`
stream, a `warm` stream is likewise at a higher temperature than a
`cool` stream and a `cool` stream is likewise at a higher
temperature than a `cold` stream. Such a stream may not normally be
considered as such. That is a `cool` stream may have a temperature
that is actually high enough to be considered hot or warm in
conventional, non-relative usage.
[0023] As used herein the term `dry` as applied to a carbonaceous
feed material is used to indicate that the feed material has a
moisture content suitable for reforming, e.g. less than about 20
weight percent, and not to imply the complete absence of
moisture.
DETAILED DESCRIPTION
I. Overview
[0024] Herein disclosed are a high temperature, high efficiency,
biomass reformer, a mixing apparatus, a synthesis gas production
system comprising same and a method of producing synthesis gas from
at least one carbonaceous material. The disclosed high temperature,
high efficiency, reformer is configured for the production of
synthesis gas from renewable and sustainable carbonaceous materials
such as biomass. Accordingly, the disclosed bioreformer, the
disclosed synthesis gas production system comprising the
bioreformer and the disclosed process for producing synthesis gas
therewith represent clean technologies. Such a reformer is
significantly more environmentally-friendly than conventional
reformers that produce synthesis gas from other sources, such as
from natural gas.
II. Synthesis Gas Production System
[0025] FIG. 1 is a schematic of a synthesis gas production system
100 according to this disclosure. Synthesis gas production system
100 comprises reformer 400 and mixing apparatus 300. As discussed
further hereinbelow, synthesis gas production system 100 can
further comprise feed handling and/or drying apparatus 200, steam
generation apparatus 500 or both. Synthesis gas production system
100 can further comprise downstream synthesis gas conversion
apparatus 700. Each of the component apparatus will be described in
more detail hereinbelow.
[0026] High Temperature, High Efficiency Biomass Reformer 400.
[0027] System 100 comprises reforming apparatus 400, also referred
to herein as biomass reformer 400. Description of reforming
apparatus 400 will now be made with reference to FIG. 2, which is a
schematic of a synthesis gas production system 100A comprising
mixing apparatus 300A, reformer 400A and steam generation apparatus
500A, according to an embodiment of this disclosure and FIG. 3,
which is a schematic of a synthesis gas production system 100B
comprising mixing apparatus 300B, reformer 400B and steam
generation apparatus 500B, according to another embodiment of this
disclosure.
[0028] Reformer 400A is a high temperature, high efficiency
reformer. In embodiments, reformer 400 is a biomass reformer.
Reformer 400A comprises a plurality of coiled tubes 410A, 410B
surrounded by enclosure, cylindrical vessel or firebox 407. In
embodiments, biomass reformer 400A is a cylindrical vessel. In
embodiments, the cylindrical vessel 407 has a height H1 in the
range of from about 40 feet (12.2 m) to about 100 feet (30.5 m),
from about 50 feet (15.2 m) to about 100 feet (30.5 m), or from
about 60 feet (18.3 m) to about 100 feet (30.5 m). In embodiments,
coiled tubes 410 have an inside diameter (ID) of at least or about
2 inches (5.1 cm), at least or about 3 inches (7.6 cm), or at least
or about 4 inches (10.2 cm). Coiled tubes 410 may be configured as
cylindrical helices and may be oriented vertically within
cylindrical vessel 407. In embodiments, each of the coiled tubes
410 has a total length or coil length that is at least 4, 5, 10,
15, 20 or 25 times the vertical height of the coiled tubes. In
embodiments, each of the coiled tubes 410 has a total length in the
range of from about 200 feet (61 m) to about 1000 feet (304.8 m),
from about 400 feet (121.9 m) to about 800 feet (243 m), or from
about 400 feet (121.9 m) to about 700 feet (213.4 m).
[0029] In embodiments, the metallurgy of the coiled tubes is
upgraded such that the tubes are operable at the high temperatures
of operation of a high temperature reformer. A `high` temperature
reformer is operable at a temperature of at least 1093.degree. C.
(2000.degree. F.). In embodiments, the coiled tubes are operable at
temperatures up to 926.degree. C. (1700.degree. F.), 982.degree. C.
(1800.degree. F.), 1038.degree. C. (1900.degree. F.), 1093.degree.
C. (2000.degree. F.), 1149.degree. C. (2100.degree. F.) and a
pressure of at least 2 psig (13.8 kPa), 5 psig (34.5 kPa), at least
20 psig (137.9 kPa), greater than or about 40 psig (275.8 kPa) or
about 45 psig (310.3 kPa) or about 50 psig (344.7 kPa). In
embodiments, the coiled tubes are fabricated from stainless steel,
such as 310 stainless steel. In embodiments, the coiled tubes are
fabricated from austenitic nickel-chromium-based superalloys or
other high temperature alloys that are resistant to hydrogen attack
and suitable for production of coiled helices, such as INCONEL.TM..
In embodiments, the coiled tubes are fabricated from INCONEL.TM.
800 HT. In embodiments, the coiled tubes are designed to provide at
least 100,000 hours of operation.
[0030] As shown in FIG. 3, a distributor or flow divider 412 can be
positioned external or internal to firebox 407 for distributing a
reformer feedstock comprising a mixture of cooled steam and dry
carbonaceous material to the plurality of coiled tubes 410. In
embodiments, distributor 412 is positioned external to vessel 407.
In embodiments, distributor 412 is configured to provide
substantially equal amounts of the reformer feed mixture to each of
the coiled tubes 410.
[0031] Distributor 412 distributes reformer feed mixture to each of
the plurality of coiled tubes 410 (410A and 410B indicated in the
embodiment of FIG. 3) via one or more reformer feed inlet lines 350
(350A and 350B depicted in the embodiment of FIG. 3). In
embodiments, mixing apparatus 300 (300A in FIG. 2; 300B in FIG. 3),
further discussed hereinbelow, comprises one or a plurality of feed
mixers 310 (mixers 310A and 310B depicted in FIG. 2; mixer 310C
depicted in FIG. 3), the output of each of which is fed via one or
more reformer feed inlet lines 350 (350A and 350B indicated in the
embodiments of FIGS. 2 and 3) into the coiled tubes 410.
[0032] The amount of superheated steam in the reformer feed mixture
is a function of the nature of the carbonaceous material (i.e. the
feedstock) used. Steam provides the additional hydrogen necessary
to produce, from the feedstock, suitable synthesis gas for
subsequent production of liquid hydrocarbons, alcohols and/or other
oxidized compounds, or other synthesis gas conversion products
therefrom. In terms of the stoichiometric ratio of carbon to
hydrogen in lower alcohols such as methanol and ethanol and
C.sup.5+ hydrocarbons, the dry feedstock may have a stoichiometric
excess of carbon relative to hydrogen. Thus water, either trapped
in the feedstock or in the form of superheated steam, or both, can
serve to provide additional hydrogen to maximize subsequent
production of synthesis gas conversion products. In embodiments,
prior to mixing, the feedstock is relatively dry, and sufficient
water is provided by combining superheated steam with the dried
feedstock material in mixing apparatus 300, as discussed
hereinbelow.
[0033] In embodiments, from about 0.09 kilograms (0.2 pounds) to
about 0.45 kilograms (1 pound), from about 0.14 kg (0.3 pounds) to
about 0.32 kg (0.7 pounds) or from about 0.14 kg (0.3 pounds) to
about 0.27 kg (0.6 pounds) of steam is added per pound of `dry`
feedstock comprising from about 4% to about 20% moisture, from
about 9% to about 18% moisture or from about 12% to about 18%
moisture, to provide the reformer feed mixture that is introduced
into the coiled tubes of the reformer. The reformer feed mixture
can have a total water to feedstock weight ratio in the range of
from about 0.2 to 1.0, from about 0.3 to about 0.7 or from about
0.3 to about 0.6.
[0034] Feedstock reformation carried out in the feedstock reformer
is endothermic. Thus, reforming apparatus 400 comprises one or more
burners 404 operable to provide the necessary heat of the
pyrolysis, reforming and/or gasification reaction(s) occurring
within the coiled tubes 410 by combusting fuel in the presence of
oxygen.
[0035] Burners 404 are desirably positioned at or near the bottom
of the reformer. Burners 404 may be positioned internal or external
to firebox 407. In embodiments, burner(s) 404 are internal to
firebox 407. The burner(s) 404 may be distributed substantially
uniformly along the diameter of vessel 407. In embodiments, the
reformer has from about 1 to about 10 burners, from about 1 to
about 4 burners, or from about 1 to about 3 burners. Oxidant
utilized by the burner(s) may be provided as air, enriched air, or
substantially pure oxygen. For example, in the embodiment of FIG.
2, each of the burners 404 is provided with air via one or more air
inlet lines 405 and fuel provided via one or more fuel inlet lines
406. The oxidant and fuel may be fed separately to each burner 404
or combined prior to entry thereto. The system can further comprise
a forced draft (FD) fan 409 configured to provide air to an air
preheater 413 configured to raise the temperature of the inlet air
from a first temperature (e.g. ambient temperature) to a
temperature in the range of from about -18.degree. C. (0.degree.
F.) to about 399.degree. C. (750.degree. F.), from about 38.degree.
C. (100.degree. F.) to about 399.degree. C. (750.degree. F.) or
from about 316.degree. C. (600.degree. F.) to about 399.degree. C.
(750.degree. F.). In embodiments, flue gas exiting steam generation
apparatus 500A (discussed further hereinbelow) is utilized to heat
the air upstream of burner(s) 404. The air may be preheated by heat
transfer with a flue gas stream in steam generator flue gas outlet
line(s) 570 exiting steam generator 501A. This flue gas may have a
temperature in the range of from about 649.degree. C. (1200.degree.
F.) to about 1260.degree. C. (2300.degree. F.), from about
760.degree. C. (1400.degree. F.) to about 1204.degree. C.
(2200.degree. F.) or from about 871.degree. C. (1600.degree. F.) to
about 1149.degree. C. (2100.degree. F.).
[0036] Fuel is provided to the one or more burners 404 via fuel
inlet line(s) 406. Any fuel known in the art can be utilized. In
embodiments, the fuel provided to the reformer is selected from the
group consisting of methane (e.g. natural gas), synthesis gas (e.g.
excess synthesis gas), tailgas (e.g. Fischer-Tropsch tailgas) and
combinations thereof. In embodiments, one or more of the burners
404 may be specially designed for burning tailgas in line 770 or a
mixture of tailgas with at least one other gas such as methane or
synthesis gas. The amount of air combined with the fuel will be
adjusted as known in the art based upon the fuel utilized and the
desired temperature within the reformer. In embodiments, the
reformer temperature is maintained at a temperature of at least
about 926.degree. C. (1700.degree. F.), 982.degree. C.
(1800.degree. F.), 1038.degree. C. (1900.degree. F.), 1093.degree.
C. (2000.degree. F.) or 1149.degree. C. (2100.degree. F.).
[0037] For greater energy independence of the overall system,
excess synthesis gas can be made and used to run a turbine and
generate electricity to power the compressors and other
electrically driven devices.
[0038] The reformer comprises one or more reformer flue gas outlet
lines 470 for flue gas exiting the reformer. Desirably, reformer
flue gas outlet line(s) 470 is positioned at or near the top of the
reformer. In the embodiment of FIG. 2, reformer flue gas outlet
lines 470 are provided a manifold 408 fluidly connecting reformer
400A with steam generation apparatus 500A. The flue gas exiting
reformer 400A can have a temperature in the range of at least
926.degree. C. (1700.degree. F.), 982.degree. C. (1800.degree. F.),
1038.degree. C. (1900.degree. F.), 1093.degree. C. (2000.degree.
F.), 1149.degree. C. (2100.degree. F.). The pressure of the flue
gas can be in the range of from about -20 inches H.sub.2O to 0 inch
H.sub.2O; from about -16 inches H.sub.2O to -2 inches H.sub.2O; or
from about -15 inches H.sub.2O to -5 inches H.sub.2O. In
embodiments, the reformer is configured for operation at a pressure
of greater than or equal to 5 psig (34.5 kPa), 30 psig (206.8 kPa),
40 psig (275.8 kPa), 45 psig (310.3 kPa) or 50 psig (344.7 kPa).
Operation of the reformer at higher pressures may allow a reduction
in the number of compression stages required upstream of the
synthesis gas conversion apparatus 700 and/or a reduction in
required compression horsepower.
[0039] Superheated steam from line(s) 550 carries the feedstock to
the reformer. In the process of heating up the feedstock upon
mixing therewith, the steam may cool to a temperature in the range
of from about 150.degree. F. (66.degree. C.) to about 1000.degree.
F. (538.degree. C.), from about 200.degree. F. (93.degree. C.) to
about 750.degree. F. (399.degree. C.), or from about 300.degree. F.
(149.degree. C.) to about 400.degree. F. (204.degree. C.). In the
process of heating up the feedstock upon mixing therewith, the
steam may cool to a temperature of approximately 204.degree. C.
(400.degree. F.) as the reformer feed mixture approaches the
reformer. In embodiments, the inlet temperature of the reformer
feed mixture entering the reformer is at a temperature of about
204.degree. C. (400.degree. F.). The exit temperature of the
synthesis gas leaving the reformer can be in the range of from
about 870.degree. C. (1600.degree. F.) to about 1205.degree. C.
(2200.degree. F.) or from about 895.degree. C. (1650.degree. F.) to
about 930.degree. C. (1700.degree. F.). In embodiments, the
reformer is operated at a pressure in the range of from about 34.5
kPa (5 psig) to about 275.8 kPa (40 psig).
[0040] Within the coiled tubes of the reformer, the carbonaceous
materials in the reformer feed are anaerobically reformed with
superheated steam to produce a product process gas comprising
synthesis gas (hydrogen and carbon monoxide). The process gas can
further comprise other components, for example, methane, carbon
dioxide, and etc. Minor amounts of other ingredients may be formed.
The reformer can comprise an external (see 414A in FIG. 2) or
internal (see 414B in FIG. 3) manifold configured to combine the
process gas from each of the coiled tubes 410 into one or more
reformer process gas outlet lines 480. As indicated in the
embodiment of FIG. 2, outlet lines 402 associated with each of the
coiled tubes can be combined via manifold 414A to provide process
gas to reformer process gas outlet line 480. In embodiments, the
reformer is configured to provide temperature, pressure and
residence time conditions suitable to provide a process gas
comprising synthesis gas having a desired molar ratio of H.sub.2 to
CO. In embodiments, the reformer is configured to provide a
synthesis gas having a H.sub.2:CO molar ratio in the range of from
about 0.7:1 to about 2:1, from about 0.7:1 to about 1.5:1 or about
1:1. In embodiments, the reformer is configured to provide a
residence time within the reformer in the range of from about 0.3 s
to about 3 s, from about 0.3 s to about 2 s, from about 0.3 s to
about 1 s, or from about 0.4 s to about 0.6 s.
[0041] For any given feedstock, a desired composition of the
resulting process gas (i.e. the proportions of hydrogen, carbon
dioxide, carbon monoxide and methane) can be provided by adjusting
the contact time in the reformer, the temperature at the reformer
outlet, the amount of steam introduced with the feed, and to a
lesser extent, the reformer pressure. In embodiments, the synthesis
gas is to be utilized downstream for the production of liquid
hydrocarbons via Fischer-Tropsch conversion. In embodiments, the
synthesis gas is to be utilized downstream for the production of
liquid hydrocarbons via Fischer-Tropsch conversion with an
iron-based catalyst. In such embodiments, the system may be
operated with a reformer exit temperature in the range of from
about 898.degree. C. (1650.degree. F.) to about 926.degree. C.
(1700.degree. F.) and a residence or contact time that is in the
range of from about 0.3 seconds to about 2.0 seconds in the
reformer. The contact or residence time can be calculated by
dividing the internal volume of the reformer by the flow rate of
the process gas exiting the reformer.
[0042] Mixing Apparatus 300.
[0043] As indicated in FIG. 1, the synthesis gas production
apparatus of this disclosure further comprises mixing apparatus 300
upstream of reformer 400. Mixing apparatus 300 is configured to
combine feedstock introduced thereto via feedstock inlet line 250
with superheated steam introduced thereto via superheated steam
line 550. As discussed further hereinbelow, the feedstock can be
provided via feedstock handling and/or drying apparatus 200
positioned upstream of mixing apparatus 300. As discussed further
hereinbelow, superheated steam can be provided via steam generation
apparatus 500 configured to utilize the heat from the reformer flue
gas and/or the reformer product gas to produce superheated steam
from boiler feed water (BFW).
[0044] As depicted in the embodiment of FIG. 2, mixing apparatus
300A can comprise one or more mixers 310 (two mixers, 310A and
310B, indicated in FIG. 2) configured to combine superheated steam
with feedstock material. Feedstock can be introduced into the
mixing apparatus via one or more feedstock inlet lines 250. The
feedstock comprises at least one carbonaceous material. In
embodiments, the feedstock comprises biomass. The feedstock can
comprise, by way of non-limiting examples, lignite, coal, red
cedar, southern pine, hardwoods such as oak, cedar, maple and ash,
bagasse, rice hulls, rice straw, weeds such as kennaf, sewer
sludge, motor oil, oil shale, creosote, pyrolysis oil such as from
tire pyrolysis plants, used railroad ties, dried distiller grains,
corn stalks and cobs, animal excrement, straw, or some combination
thereof. The hydrogen and oxygen content for the various materials
differ and, accordingly, operation of the system (e.g. amount of
superheated steam combined with the feedstock in the mixing
apparatus, the reformer temperature and pressure, the reformer
residence time) can be adjusted as known in the art to provide a
process gas comprising synthesis gas having a suitable molar ratio
of H.sub.2:CO for a desired subsequent synthesis conversion
application. The feedstock introduced into the mixing apparatus can
have an average particle size in the range of from about 0.006 inch
(0.015 cm) to about 0.3 inch (0.8 cm), from about 0.01 inch (0.025
cm) to about 0.25 inch (0.63 cm) or from about 0.1 inch (0.25 cm)
to about 0.187 inch (0.5 cm). In embodiments, the feedstock
introduced into the mixing apparatus has an average particle size
in the range of from about 3.9 E-5 inch (0.0001 cm) to about 1 inch
(2.54 cm), from about 0.01 inch (0.0254 cm) to about 0.5 inch (1.27
cm) or from about 0.09 inch (0.24 cm) to about 0.2 inch (0.508 cm).
In embodiments, the feedstock introduced into the mixing apparatus
has an average particle size of less than about 0.01 inch (0.025
cm), less than about 0.25 inch (0.63 cm) or less than about 3/16
inch (0.476 cm). The feedstock introduced into the mixing apparatus
can have a moisture content in the range of from about 4 weight
percent to about 20 weight percent, from about 9 weight percent to
about 18 weight percent, from about 5 weight percent to about 18
weight percent or from about 9 weight percent to about 15 weight
percent. As discussed further hereinbelow and mentioned
hereinabove, a system of this disclosure can further comprise,
upstream of the mixing apparatus and connected therewith via one or
more lines 250, feedstock handling and/or drying apparatus 200.
[0045] Within the mixing apparatus 300, feedstock is combined with
superheated steam to provide a reformer feed mixture. In the
embodiment of FIG. 2, feedstock in line 250 is divided via lines
250A and 250B and introduced into mixers 310A and 310B
respectively. In embodiments, one or more spent catalyst recycle
lines 755 is configured to directly or indirectly recycle at least
a portion of a catalyst/conversion product (e.g. catalyst/wax or
catalyst/alcohol) stream produced in a synthesis gas conversion
apparatus 700 to the reformer. Superheated steam, which may be
produced via steam generation apparatus 500 as further described
hereinbelow, is introduced via superheated steam lines 550, 550A
and 550B to mixing apparatus 300A. In embodiments, the mixing
apparatus is configured to combine the feedstock in feedstock line
250 with superheated steam having a temperature in the range of
from about 400.degree. F. (204.4.degree. C.) to about 1000.degree.
F. (537.8.degree. C.), from about 600.degree. F. (315.6.degree. C.)
to about 950.degree. F. (510.degree. C.) or from about 400.degree.
F. (204.4.degree. C.) to about 900.degree. F. (482.2.degree. C.)
and/or a pressure in the range of from about 150 psig (1034.2 kPa)
to about 400 psig (2757.9 kPa), from about 200 psig (1378.9 kPa) to
about 375 psig (2585.5 kPa) or from about 250 psig (1723.7 kPa) to
about 350 psig (2413.2 kPa). In embodiments, a system of this
disclosure further comprises steam generation apparatus 500
configured to provide superheated steam for introduction into
mixing apparatus 300 as further described hereinbelow.
[0046] In the embodiment of FIG. 2, superheated steam is introduced
into each of the mixers 310A and 310B, respectively, via
superheated steam lines 550A and 550B. The reformer feed mixture
comprising feedstock and steam is introduced into the reformer via
one or more reformer inlet lines 350. The feedstock/steam mixture
from each mixer 310 may be introduced into a coiled tube 410. For
example, in the embodiment of FIG. 2, feedstock/steam exiting
mixers 310A and 310B via lines 350A and 350B, respectively, are
introduced into coiled tubes 410A and 410B, respectively. In the
embodiment of FIG. 3, the feedstock/steam mixture exiting mixing
vessel 310C of system 100B is introduced via line 350, reformer
feed distributor 412 and feed inlet lines 350A and 350B into coiled
tubes 410A and 410B, respectively. Other combinations of number of
mixers, manifolding of the outlets thereof, and distributors are
envisioned and not beyond the scope of this disclosure.
[0047] As indicated in FIG. 3, the mixing vessel 310C can be a
cylindrical vessel having a conical bottom 320. In embodiments,
superheated steam is introduced at or near the bottom or into a
conical section 320 at or near the bottom of the mixer. Feedstock
may be introduced, in embodiments, at or near the top of the mixer.
In embodiments, the mixture exits out the bottom of the mixing
vessel.
[0048] In embodiments, the mixing vessel(s) (310A/310B/310C) are
pressure vessels configured for operation at a pressure in the
range of from about 5 psig (34.5 kPa) to about 50 psig (344.7 kPa),
from about 30 psig (206.8 kPa) to about 50 psig (344.7 kPa), from
about 45 psig (310.3 kPa) to about 50 psig (344.7 kPa), or
configured for operation at or greater than about 30 psig (206.8
kPa), 45 psig (310.3 kPa) or 50 psig (344.7 kPa). In embodiments,
the mixing vessels are configured for operation at a temperature in
the range of from about 150.degree. F. (66.degree. C.) to about
1000.degree. F. (538.degree. C.), from about 200.degree. F.
(93.degree. C.) to about 750.degree. F. (399.degree. C.), or from
about 300.degree. F. (149.degree. C.) to about 400.degree. F.
(204.degree. C.).
[0049] The mixing apparatus may be configured to provide a reformer
feed mixture by combining from about 0.3 pound of steam per pound
of feedstock to about 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1 pound of
superheated steam per pound of feedstock. In embodiments, the
mixing apparatus is configured to provide a reformer feed mixture
by combining less than or equal to about 1, 0.9, 0.8, 0.7, 0.6, 0.5
or less than or equal to about 0.4 pound of superheated steam per
pound of feedstock.
[0050] As indicated in FIG. 3 and discussed further hereinbelow, a
portion of the saturated steam exiting the steam generator via one
or more steam generator steam outlet line(s) 560 can be sent via
one or more line(s) 560A and 560C to an excess steam condenser 516.
Condensate from excess steam condenser 516 can be combined with
condensate from elsewhere in the system (for example, with
condensate in condensate outlet line 282 from a dryer air preheater
of feed handling and/or drying apparatus 200, as discussed further
hereinbelow). Condensate can be collected for disposal and/or
recycle and reuse via line 283.
[0051] Steam Generation Apparatus 500.
[0052] The synthesis gas production system disclosed herein may
further comprise steam generation apparatus 500 configured to
provide superheated steam for reforming feedstock within reformer
400/400A/400B. As depicted in the embodiment of FIG. 1, water (e.g.
boiler feed water or BFW) is introduced into steam generation
apparatus 500 via one or more BFW inlet lines 580, `hot` reformer
flue gas is introduced into steam generation apparatus 500 via one
or more reformer flue gas outlet lines 470, `hot` product process
gas is introduced into steam generation apparatus 500 via one or
more reformer process gas outlet lines 480, superheated steam exits
steam generation apparatus 500 via one or more superheated steam
outlet lines 550, saturated steam exits steam generation apparatus
500 via one or more steam generator steam outlet lines 560, `cool`
flue gas exits steam generation apparatus 500 via one or more steam
generator flue gas outlet lines 570 and `cool` process gas exits
steam generation apparatus 500 via one or more steam generator
process gas outlet lines 450.
[0053] Description of a suitable steam generation apparatus will
now be made with reference to FIG. 2. In the embodiment of FIG. 2,
steam generation apparatus 500A comprises reformer flue gas and
reformer effluent steam generator 501A and steam superheater 501B.
Reformer flue gas and reformer effluent steam generator 501A is
configured to produce saturated steam by heat transfer from the
`hot` reformer effluent process gas and the `warm` reformer flue
gas exiting steam superheater 501B. Reformer effluent process gas
is introduced into reformer flue gas and reformer effluent steam
generator 501A via reformer process gas outlet line(s) 480. The
`hot` process gas introduced into reformer flue gas and reformer
effluent steam generator 501A via reformer process gas outlet
line(s) 480 may have a temperature in the range of from about
870.degree. C. (1600.degree. F.) to about 1205.degree. C.
(2200.degree. F.) or from about 895.degree. C. (1650.degree. F.) to
about 930.degree. C. (1700.degree. F.). In embodiments, the `hot`
process gas has a pressure in the range of from about 34.5 kPa (5
psig) to about 275 KPa (40 psig). Within reformer flue gas and
reformer effluent steam generator 501A, steam is commonly generated
from the flue gas and the process gas, although the two gases are
not mixed. `Cool` reformer process gas leaves reformer flue gas and
reformer effluent steam generator 501A via steam generator process
gas outlet line(s) 450. The `cool` process gas exiting reformer
flue gas and reformer effluent steam generator 501A via steam
generator process gas line(s) 450 may have a temperature in the
range of from about 400.degree. C. (752.degree. F.) to about
800.degree. C. (1472.degree. F.), from about 400.degree. C.
(752.degree. F.) to about 600.degree. C. (1112.degree. F.) or about
400.degree. C. (752.degree. F.) and/or a pressure in the range of
from about 5 psig (34.5 kPa) to about 50 psig (344.7 kPa), from
about 10 psig (68.9 kPa) to about 40 psig (275.8 kPa) or from about
20 psig (137.9 kPa) to about 30 psig (206.8 kPa).
[0054] Reformer flue gas is introduced into reformer flue gas and
reformer effluent steam generator 501A via reformer flue gas outlet
line(s) 470. The `hot` flue gas introduced into reformer flue gas
and reformer effluent steam generator 501A via reformer flue gas
outlet line(s) 470 may have a temperature in the range of from
about 530.degree. F. (276.7.degree. C.) to about 1500.degree. F.
(815.6.degree. C.), from about 530.degree. F. (276.7.degree. C.) to
about 1200.degree. F. (648.9.degree. C.) or about 530.degree. F.
(276.7.degree. C.) and/or a pressure in the range of from about -20
inches H.sub.2O to 0 inches H.sub.2O; from about -15 inches
H.sub.2O to about -5 inches H.sub.2O; or from about -10 inches
H.sub.2O to about -5 inches H.sub.2O. As depicted in FIG. 2, in
embodiments the reformer flue gas passes through steam superheater
501B, as discussed further hereinbelow, prior to introduction into
reformer flue gas and reformer effluent steam generator 501A. In
such instances, the `warm` flue gas introduced into the reformer
flue gas and reformer effluent steam generator 501A may have a
temperature in the range of from about 1350.degree. F.
(732.2.degree. C.) to about 2050.degree. F. (1121.1.degree. C.),
from about 1450.degree. F. (787.8.degree. C.) to about 1950.degree.
F. (1065.6.degree. C.) or from about 1350.degree. F. (732.2.degree.
C.) to about 1850.degree. F. (1010.degree. C.) and/or a pressure in
the range of from about -20 inches H.sub.2O to 0 inch H.sub.2O; -16
inches H.sub.2O to -5 inches H.sub.2O; -15 inches H.sub.2O to 5
inches H.sub.2O. In embodiments, the temperature of the `warm` flue
gas is about 150 degrees less than that of the `hot` flue gas, i.e.
the flue gas temperature drop across steam superheater 501B is in
the range of from about 130-170 degrees, from about 140-160
degrees, or about 150 degrees.
[0055] `Cool` reformer flue gas leaves reformer flue gas and
reformer effluent steam generator 501A via steam generator flue gas
outlet line(s) 570. The `cool` flue gas exiting reformer flue gas
and reformer effluent steam generator 501A via steam generator flue
gas outlet line(s) 570 may have a temperature in the range of from
about 50.degree. F. (10.degree. C.) to about 400.degree. F.
(204.4.degree. C.), from about 200.degree. F. (93.3.degree. C.) to
about 400.degree. F. (204.4.degree. C.) or about 400.degree. F.
(204.4.degree. C.) and/or a pressure in the range of from about -20
inches H.sub.2O to about 20 inches H.sub.2O; from about -16 inches
to about 20 inches H.sub.2O; or from about -15 inches H.sub.2O to
about -10 inches H.sub.2O. Induced draft (ID) fan 573 can serve to
draw `cool` reformer flue gas exiting reformer flue gas and
reformer effluent steam generator 501A via steam generator flue gas
outlet line(s) 570 through air preheater 413, discussed
hereinabove. Heat transfer to the air within air preheater 413 may
provide a `cold` flue gas for use elsewhere in the system, for
example in a dryer air heater of a feed handling and/or drying
apparatus 200, as further discussed hereinbelow. The `cold` flue
gas passing out of air preheater 413 in line(s) 570 may have a
temperature in the range of from about -18.degree. C. (0.degree.
F.) to about 399.degree. C. (750.degree. F.), from about 38.degree.
C. (100.degree. F.) to about 399.degree. C. (750.degree. F.) or
from about 316.degree. C. (600.degree. F.) to about 399.degree. C.
(750.degree. F.) and/or a pressure in the range of from about -20
inches H.sub.2O to about 20 inches H.sub.2O; from about -16 inches
to about 20 inches H.sub.2O; or from about -15 inches H.sub.2O to
about -10 inches H.sub.2O.
[0056] One or more steam generator steam outlet lines 560 carries
steam (e.g. saturated steam) from reformer flue gas and reformer
effluent steam generator 501A. A portion of the saturated steam may
be directed via one or more steam export lines 560A for export to
another apparatus or use elsewhere in the system. As indicated in
the embodiment of FIG. 2, all or a portion of the saturated steam
produced in reformer flue gas and reformer effluent steam generator
501A can be directed to steam superheater 501B configured to
produce superheated steam. Steam superheater 501B is configured to
provide superheated steam at a temperature in the range of from
about 400.degree. F. (204.4.degree. C.) to about 1000.degree. F.
(537.8.degree. C.), from about 600.degree. F. (315.6.degree. C.) to
about 950.degree. F. (510.degree. C.) or from about 400.degree. F.
(204.4.degree. C.) to about 900.degree. F. (482.2.degree. C.)
and/or a pressure in the range of from about 150 psig (1034.2 kPa)
to about 400 psig (2757.9 kPa), from about 200 psig (1379 kPa) to
about 375 psig (2585.5 kPa) or from about 250 psig (1723.7 kPa) to
about 350 psig (2413.2 kPa). In embodiments, steam superheater 501B
operates via heat transfer from the `hot` reformer flue gas in
reformer flue gas outlet line(s) 470. Steam superheater 501B may be
configured on a manifold or header 408 comprising reformer flue gas
outlet(s) 470. As mentioned hereinabove, the `warm` flue gas
exiting the steam superheater may have a temperature in the range
of from about 1500.degree. F. (815.6.degree. C.) to about
2200.degree. F. (1204.4.degree. C.), from about 1600.degree. F.
(871.1.degree. C.) to about 2150.degree. F. (1176.7.degree. C.) or
from about 1600.degree. F. (871.1.degree. C.) to about 2100.degree.
F. (1148.9.degree. C.) and/or a pressure in the range of from about
-20 inches H.sub.2O to 0 inches H.sub.2O; -16 inches H.sub.2O to -5
inches H.sub.2O; -15 inches H.sub.2O to 5 inches H.sub.2O. As
discussed hereinabove, superheated steam exiting steam superheater
501B can be introduced into the mixing apparatus 300 via one or
more superheated steam lines 550.
[0057] Reformer flue gas and reformer effluent steam generator 501A
may, as known in the art, be associated with one or more blowdown
drums 515 configured to purge water off and control the solids
level within reformer flue gas and reformer effluent steam
generator 501A.
[0058] Description of a suitable steam generation apparatus
according to another embodiment of this disclosure will now be made
with reference to FIG. 3. In the embodiment of FIG. 3, the steam
generation apparatus 500B comprises flue gas steam generator 501A''
and reformer effluent steam generator 501A'. In the embodiment of
FIG. 3, `hot` reformer effluent process gas exiting reformer 400B
via reformer process gas outlet lines 480 passes through reformer
effluent steam generator 501A', configured for transfer of heat
from the `hot` reformer process gas to BFW introduced thereto via
BFW inlet line 580. `Cool` process gas exiting reformer effluent
steam generator 501A' via steam generator process gas outlet line
450 may have a temperature in the range of from about 752.degree.
F. (400.degree. C.) to about 1472.degree. F. (800.degree. C.), from
about 752.degree. F. (400.degree. C.) to about 1112.degree. F.
(600.degree. C.) or about 752.degree. F. (400.degree. C.) and/or a
pressure in the range of from about 5 psig (34.5 kPa) to about 50
psig (344.7 kPa), from about 10 psig (68.9 kPa) to about 40 psig
(275.8 kPa) or from about 20 psig (137.9 kPa) to about 30 psig
(206.8 kPa).
[0059] Reformer flue gas outlet line(s) 470 may fluidly connect
reformer 400B with steam superheater 501B'. As discussed in regard
to FIG. 2, steam superheater 501B' is configured to produce
superheated steam having a temperature in the range of from about
400.degree. F. (204.4.degree. C.) to about 1000.degree. F.
(537.8.degree. C.), from about 600.degree. F. (315.6.degree. C.) to
about 950.degree. F. (510.degree. C.) or from about 900.degree. F.
(482.2.degree. C.) and/or a pressure in the range of from about 150
psig (1034.2 kPa) to about 400 psig (2757.9 kPa), from about 200
psig (1379 kPa) to about 375 psig (2585.5 kPa) or from about 250
psig (1723.7 kPa) to about 350 psig (2413.2 kPa). One or more
superheated steam lines 550 are configured to carry the superheated
steam from steam superheater 501B' to mixing vessel(s) 310C. The
`warm` flue gas exiting steam superheater 501B' has a temperature
in the range of from about 1350.degree. F. (732.2.degree. C.) to
about 2050.degree. F. (1121.1.degree. C.), from about 1450.degree.
F. (787.8.degree. C.) to about 1950.degree. F. (1065.6.degree. C.)
or about 1850.degree. F. (1010.degree. C.) and/or a pressure in the
range of from about -20 inches H.sub.2O to 0 inch H.sub.2O; -16
inches H.sub.2O to -5 inches H.sub.2O; -15 inches H.sub.2O to 5
inches H.sub.2O and passes through flue gas steam generator 501A'',
configured for transferring heat from the `warm` reformer flue gas
to the steam in line 580A. One or more lines 560 are configured to
carry saturated steam exiting flue gas steam generator 501A''.
[0060] One or more steam generator flue gas outlet lines 570 are
configured to carry `cool` flue gas from flue gas steam generator
501A''. As mentioned hereinabove, the `cool` flue gas exiting flue
gas steam generator 501A'' can have a temperature in the range of
from about 50.degree. F. (10.degree. C.) to about 400.degree. F.
(204.4.degree. C.), from about 200.degree. F. (93.3.degree. C.) to
about 400.degree. F. (204.4.degree. C.) or about 400.degree. F.
(204.4.degree. C.) and/or a pressure in the range of from about -20
inches H.sub.2O to about 20 inches H.sub.2O; from about -16 inches
to about 20 inches H.sub.2O; or from about -15 inches H.sub.2O to
about -10 inches H.sub.2O. As discussed with regard to FIG. 2, the
`cool` flue gas in steam generator flue gas outlet line 570 may be
used to heat combustion air in combustion air preheater 413.
Combustion air preheater 413 may be configured to heat air
introduced thereto via FD fan 406 and one or more air inlet lines
405 from a first lower temperature (e.g. ambient temperature) to a
second higher temperature in the range of from about 38.degree. C.
(100.degree. F.) to about 399.degree. C. (750.degree. F.), from
about 316.degree. C. (600.degree. F.) to about 399.degree. C.
(750.degree. F.) or about 399.degree. C. (750.degree. F.) for
introduction into the reformer burner(s). `Cold` flue gas exiting
air preheater 413 may have a temperature in the range of from about
-18.degree. C. (0.degree. F.) to about 399.degree. C. (750.degree.
F.), from about 38.degree. C. (100.degree. F.) to about 399.degree.
C. (750.degree. F.) or from about 316.degree. C. (600.degree. F.)
to about 399.degree. C. (750.degree. F.) and/or a pressure in the
range of from about -20 inches H.sub.2O to about 20 inches
H.sub.2O; from about -16 inches to about 20 inches H.sub.2O; or
from about -15 inches H.sub.2O to about -10 inches H.sub.2O. The
`cold` flue gas may be utilized elsewhere in the refinery, for
example, in a dryer air heater of a feed handling and/or drying
apparatus, as further discussed hereinbelow.
[0061] It will be apparent to those of skill in the art that flue
gas steam generator 501A'' and reformer effluent steam generator
501A' of the embodiment of FIG. 3 may be combined within a single
vessel as indicated in the embodiment of FIG. 2.
[0062] Feed Handling and Drying Apparatus 200.
[0063] A system of this disclosure may further comprise feed
handling and/or drying apparatus configured to provide feed
material of a desired average particle size, composition and/or
moisture content to the downstream mixing apparatus. In
embodiments, the feed handling and/or drying apparatus is
substantially as disclosed in U.S. Pat. No. 7,375,142, the
disclosure of which is hereby incorporated herein in its entirety
for all purposes not contrary to this disclosure.
[0064] Suitable feed handling and/or drying apparatus can comprise
an unloading and tramp metal removal zone I, a comminuting zone II,
a drying zone III, a reformer feed hopper zone IV, or some
combination of two or more thereof. A feed handling and/or drying
apparatus will now be described with reference to FIG. 4, which is
a schematic of a feeding and drying apparatus 200A according to an
embodiment of this disclosure. Feed handling and/or drying
apparatus 200A comprises unloading and tramp metal removal zone I
configured for unloading of feed material and removal of
undesirables therefrom. Unloading and tramp removal zone I can
comprise a truck unloading hopper 205 into which delivered feed
material is deposited. Truck unloading hopper 205 may be associated
with a tramp metal detector 204 configured to determine the
presence or absence of undesirables such as metals in the feed
material. Unloading and tramp removal zone I can further comprise a
conveyor 203 configured to convey feed material onto a weigh belt
feeder 206. A tramp metal separator 207 is configured to remove
tramp metal and other undesirables from the feed material
introduced thereto. Removed undesirables can be introduced via line
208 into and stored in a bin 209 for disposal.
[0065] Comminuting zone II can be positioned downstream of
unloading and tramp removal zone I, as indicated in FIG. 4, or can
be downstream of an unloading zone (i.e. in the absence of a tramp
removal zone). Comminuting zone II comprises apparatus configured
to comminute the feed material. In embodiments, the comminuting
zone comprises at least one grinder 210. A comminuting zone II may
be used depending on the consistency of the feedstock. In
embodiments, the feedstock is primarily wood and/or other organic
material. Grinder 210 may be used if the feedstock is clumped
together, in unusually large conglomerates, or if the feedstock
needs to be further ground before being dried. After the feedstock
is optionally subjected to grinding, the ground material may be
passed via grinder outlet line 212 into one or more grinder
discharge cyclones 220 configured to separate a larger average size
fraction of feed material from a smaller sized fraction. The larger
sized fraction may be introduced via one or more grinder discharge
cyclone outlet lines 225 into one or more dryers 260 of dryer zone
III configured to reduce the moisture content of the material fed
thereto. The smaller sized fraction from grinder discharge cyclone
220 may be passed via grinder discharge fines outlet line 222 and
grinder discharge blower 230 into a dryer baghouse 240 of drying
zone III, as further discussed hereinbelow. Drying zone III
comprises at least one dryer 260 configured to reduce the moisture
content of feed material introduced therein. In the embodiment of
FIG. 4, drying zone III comprises dryer 260, dryer air heater 280,
dryer cyclone 265, dryer baghouse 240, accumulator 245, dryer
exhaust fan 241 and dryer stack 246. Various embodiments may
comprise any combination of these components. Within drying zone
III, the feedstock is dried to a moisture content in the range of
from about 4% to about 20%, from about 5% to about 15% or from
about 9% to about 15%. The flue gas and air fed into dryer 260
mixes with comminuted feedstock to dry it, purge it and heat it for
further processing.
[0066] An air supply fan 261 is configured to introduce air via
line 262 and reformer flue gas (e.g. `cold` reformer flue gas from
air preheater 413) via line 570 into dryer air heater 280. The flue
gas may be added upstream of dryer air preheater 280 to prevent
above 400.degree. F. (204.4.degree. C.) to the inlet of dryer 260,
preventing fire therein. As mentioned hereinabove, the `cold` flue
gas may have a temperature in the range of from about -18.degree.
C. (0.degree. F.) to about 399.degree. C. (750.degree. F.), from
about 38.degree. C. (100.degree. F.) to about 399.degree. C.
(750.degree. F.) or from about 316.degree. C. (600.degree. F.) to
about 399.degree. C. (750.degree. F.) and/or a pressure in the
range of from about -20 inches H.sub.2O to about 20 inches
H.sub.2O; from about -16 inches to about 20 inches H.sub.2O; or
from about -15 inches H.sub.2O to about -10 inches H.sub.2O. In
embodiments, the flue gas introduced via line 570 comprises about
80% nitrogen and 20% CO.sub.2.
[0067] A portion of the effluent steam from reformer effluent and
reformer flue gas steam generator 501A or from flue gas steam
generator 501A'' can be introduced via line 560A or 560D into dryer
air preheater 280. The steam introduced into dryer air preheater
280 may have a temperature in the range of from about 150.degree.
F. (65.6.degree. C.) to about 500.degree. F. (260.degree. C.), from
about 250.degree. F. (121.1.degree. C.) to about 450.degree. F.
(232.2.degree. C.) or from about 300.degree. F. (148.9.degree. C.)
to about 400.degree. F. (204.4.degree. C.) and/or a pressure in the
range of from about 70 psig (482.6 kPa) to about 300 psig (2068.4
kPa), from about 150 psig (1034.2 kPa) to about 300 psig (2068.4
kPa) or from about 250 psig (1723.7 kPa) to about 300 psig (2068.4
kPa). Condensate outlet line 282 is configured for removal of
condensate from air dryer 280. The pressure of the condensate may
be reduced downstream of the air dryer 280 and the condensate
combined as indicated in FIG. 3 with condensate from excess steam
condenser 516. Heated air exiting dryer air heater 280 via heated
air line 284 may have a temperature in the range of from about
-18.degree. C. (0.degree. F.) to about 204.degree. C. (400.degree.
F.), from about -18.degree. C. (0.degree. F.) to about 149.degree.
C. (300.degree. F.) or from about -18.degree. C. (0.degree. F.) to
about 93.3.degree. C. (200.degree. F.). Desirably, the heated air
temperature does not exceed 400.degree. F.
[0068] Heated air line 284 fluidly connects dryer air heater 280
with dryer 260. Drying zone III may further comprise a heated air
distributor 286 configured to divide heated air line 284 into a
plurality of heated air dryer inlet lines. For example, in the
embodiment of FIG. 4, distributor 286 divides the flow of air from
heated air line 284 into three heated air dryer inlet lines
284A-284C. Air passing through dryer 260 may comprise entrained
feed material. Accordingly, drying zone III can comprise one or
more dryer cyclones 265 configured to separate solids from the air
exiting dryer 260. In the embodiment of FIG. 4, air exiting dryer
260 via dryer vent lines 286A-286C is combined via air manifold 287
into dryer vent line 281 which is fed into dryer cyclone 265. It is
to be noted that, although three air inlet and air outlet (vent)
lines are shown in the embodiment of FIG. 4, any number of air
inlet lines and outlet lines may be utilized. Additionally, the
number of air inlet lines to dryer 260 need not be equal to the
number of air outlet or vent lines.
[0069] Dryer cyclone 265 is configured to remove solids from the
vent gas exiting dryer 260. Air and any fines entrained therein
exit dryer cyclone 265 via dryer cyclone fines outlet line 266,
while solids exit dryer cyclone 265 via dryer cyclone solids outlet
line 267. Line 267 may be fluidly connected with reformer feed
hopper inlet line 276. Dryer cyclone fines outlet line 266 may be
configured to introduce air and entrained fines into dryer baghouse
240 along with fines introduced thereto from grinder discharge
cyclone 220, grinder discharge cyclone outlet line 222, grinder
discharge blower 230 and/or grinder discharge blower outlet line
231. In embodiments, dryer cyclone 265 is configured to provide
solids having a particle size of greater than 3/32'' (2.5 mm) or
greater than 3/16'' (4.8 mm) into dryer cyclone solids outlet line
267. In embodiments, dryer cyclone 265 is configured to separate
solids having a particle size of less than 3/16'' into dryer
cyclone fines outlet line 266. In embodiments, dryer cyclone 265
has an efficiency of at least 85, 90, 92, 95, 96, 97, or 98
percent.
[0070] One or more dryer baghouses 240 are configured to remove
solids from the air introduced thereto. One or more dryer baghouse
solids outlet lines 243 are configured to introduce solids
separated within dryer baghouse 240 into reformer feed hopper
cyclone inlet line 276 of reformer feed hopper zone IV, further
discussed hereinbelow. In embodiments, dryer baghouse 240 is
configured to provide solids having a particle size of greater than
20, 15, 10 or 5 .mu.m into dryer baghouse solids outlet line 243.
In embodiments, dryer baghouse 240 is configured to separate solids
having a particle size of less than 10 um into dryer baghouse fines
outlet line 244.
[0071] One or more dryer baghouse fines outlet lines 244 are
configured to introduce gas from dryer baghouse 240 into dryer
stack 246, optionally via dryer exhaust fan 241 and line 247. A
line 251 may introduce air into an accumulator 245 prior to
introduction into dryer baghouse(s) 240.
[0072] Feed handling and/or drying apparatus 200A can further
comprise a reformer feed hopper zone IV. The reformer feed hopper
zone IV comprises at least one reformer feed hopper and a feeder
configured for feeding feed material into mixing apparatus 300. In
the embodiment of FIG. 4, reformer feed hopper zone IV comprises
reformer feed hopper 295 and mixing vessel rotary feeder 297.
Reformer feed hopper zone IV can further comprise a surge hopper
270, a reformer feed hopper blower 275 and a reformer feed hopper
cyclone 290, as indicated in the embodiment of FIG. 4. One or more
dried feed lines 294 are configured to introduce dried feed
material from one or more dryers 260 of dryer zone III into
reformer feed hopper zone IV. The feed material may be introduced
into a surge hopper 270, configured for storage of surplus dried
feed material and supply therefrom to reformer feed hopper 295. A
reformer feed hopper blower 275 may be incorporated into zone IV
for pushing dried feed material and/or separated solids introduced
into reformer feed hopper cyclone inlet line 276 from dryer(s) 260
and/or surge hopper(s) 270 via line(s) 271, from dryer cyclone(s)
265 via dryer cyclone solids outlet line(s) 267, from dryer
baghouse(s) 240 via dryer baghouse solids outlet line(s) 243 into
reformer feed hopper cyclone(s) 290. In alternative embodiments,
the material in reformer feed hopper inlet line(s) 276 is
introduced directly into reformer feed hopper 295. Reformer feed
hopper cyclone 290 is configured to separate fines from material
introduced therein. In embodiments, a reformer feed hopper cyclone
outlet line 292 is configured to introduce fines separated within
reformer feed hopper cyclone 290 into dryer baghouse 240,
optionally via grinder discharge blower outlet line 231 as
indicated in the embodiment of FIG. 4. In embodiments, reformer
feed hopper cyclone 290 is configured to provide solids having an
average particle size in the range of from about 3.9 E-5 inch
(0.0001 cm) to about 1 inch (2.54 cm), from about 0.01 inch (0.0254
cm) to about 0.5 inch (1.27 cm) or from about 0.09 inch (0.24 cm)
to about 0.2 inch (0.51 cm) into reformer feed hopper 295. In
embodiments, the feed material in reformer feed hopper 295 is of a
size allowing it to pass through a 4.8 millimeter ( 3/16 inch)
screen. In embodiments, reformer feed hopper cyclone 290 is
configured to separate solids having a particle size of less than
3/16'' (0.48 cm) into reformer feed hopper cyclone fines outlet
line 292. Feed material is introduced into reformer feed hopper 295
via reformer feed hopper inlet line 276 and optionally reformer
feed hopper cyclone 290. In embodiments, reformer feed hopper 295
is a cylindrical vessel having a conical bottom. In embodiments,
reformer feed hopper cyclone 295 provides an efficiency of at least
80, 85, 90, 92, 95, 96, 97 or 98 percent.
[0073] Mixing vessel rotary feeder 297 is configured to introduce
feed material from reformer feed hopper 295 into mixing apparatus
300. As needed, feed material is fed from reformer feed hopper 295
and rotary feeder 297 into mixing apparatus 300. Rotary feeder 297
may be substantially as described in U.S. Pat. No. 7,375,142. Feed
material exits reformer feed hopper 295 via feed hopper outlet line
296, which fluidly connects reformer feed hopper 295 with mixing
vessel rotary feeder 297.
[0074] In embodiments, one or more purge lines 291 is configured to
introduce purge gas (e.g. flue gas or plant air) for purge into and
push feed material through reformer feed hopper 295. In
embodiments, the purge gas is flue gas comprising about 80%
nitrogen and about 20% carbon dioxide, helping to insure that the
reformation process in reformer 400 will be carried out
anaerobically. Reformer feed hopper 295 may also include a vent for
venting flue gas. From reformer feed hopper 295, feedstock settles
into feed hopper outlet line(s) 296, which extends from the bottom
of reformer feed hopper 295. The feedstock is metered by rotary
valve 297 into feedstock inlet line 250, along which it is
entrained with steam under pressure entering from superheated steam
line 550 of mixing apparatus 300. To keep feedstock flowing into
the stream of steam, and in order to counter steam back pressure in
line 250, a supply of gas is moved through rotary feeder purge gas
inlet line 288 via a compressor to an inlet just below valve 297.
To prevent the pressure in feedstock inlet line 250 from blowing
feedstock back into rotary valve 297, some of the gas is also split
off from rotary feeder purge gas inlet line 288 and fed to an inlet
of mixing vessel rotary feeder 297. Rotary feeder 297 includes a
central rotor having a plurality of vanes which divide the interior
of valve 297 into separate compartments. Opposite the inlet on
rotary valve 297, is an outlet pressure vent line 289. As the rotor
of valve 297 rotates, the compartment formed by the vanes at the
top fill with feedstock. That filled compartment is then rotated
until it opens to the inlet, where it is pressurized with incoming
gas. As the rotor rotates further, the feedstock filled and
pressurized chamber opens into reformer feedstock inlet line 250.
Since the pressure in the rotor chamber is equalized with the
pressure in line 250, the feedstock falls down into feedstock inlet
line 250. As the valve rotor continues on its journey, it is
eventually vented through outlet pressure vent line 289, such that
when the chamber again reaches feed hopper outlet line 296, it is
depressurized and will not vent back up into feed hopper outlet
line 296. After feedstock has moved through rotary feeder valve 297
and into feedstock line 250, it feeds by gravity into a mixing
chamber or position along mixing apparatus feedstock inlet line 250
where the feedstock is mixed with superheated steam (e.g. steam
having a temperature of about 510.degree. C. (950.degree. F.)) from
superheated steam line 550.
II. Method of Producing Synthesis Gas
[0075] Also disclosed herein is a method of producing synthesis gas
via reforming of carbonaceous material. In embodiments, the
carbonaceous material comprises primarily biomass. The basic steps
in the method of producing synthesis gas according to this
disclosure are depicted in the flow diagram of FIG. 5. As indicated
in FIG. 5, a method of producing synthesis gas conversion product
600 comprises preparing carbonaceous feedstock at 610, preparing
reformer feed at 620 and reforming the reformer feed at 630.
Preparing carbonaceous feed material 610 comprises comminuting
and/or drying a suitable carbonaceous feed material. In
embodiments, the source of the carbonaceous feedstock comprises
biomass. In embodiments, the carbonaceous feedstock comprises at
least one component that is or that is derived from lignite, coal,
red cedar, southern pine, hardwoods such as oak, cedar, maple and
ash, bagasse, rice hulls, rice straw, weeds such as kennaf, sewer
sludge, motor oil, oil shale, creosote, pyrolysis oil such as from
tire pyrolysis plants, used railroad ties, dried distiller grains,
corn stalks and cobs, animal excrement, straw, and combinations
thereof.
[0076] Preparing Carbonaceous Feedstock 610.
[0077] In embodiments, preparing the carbonaceous feedstock 610
comprises sizing (comminuting) at least one carbonaceous feedstock
such that it is of a desirable size for effective reforming. In
embodiments, preparing the carbonaceous feedstock comprises
reducing the average particle size of the feedstock to less than
about 5/8.sup.th inch (15.9 mm), 1/2 inch (12.7 mm), or less than
about 3/16.sup.th of an inch (4.8 mm). The carbonaceous feedstock
may be sized by any methods known in the art. In embodiments, a
carbonaceous material is sized by introducing it into one or more
grinders 210, as discussed above with reference to FIG. 4.
[0078] In embodiments, preparing the carbonaceous feed material
comprises drying the carbonaceous feedstock to a moisture content
in the range of from about 4 weight percent to about 20 weight
percent, from about 6 weight percent to about 16 weight percent, or
from about 12 weight percent to about 18 weight percent. In
embodiments, preparing the carbonaceous feed material comprises
drying the carbonaceous feedstock to a moisture content in the
range of from about 4 weight percent to about 20 weight percent,
from about 5 weight percent to about 20 weight percent, from about
10 weight percent to about 20 weight percent or from about 5 weight
percent to about 18 weight percent. In embodiments, preparing the
carbonaceous feedstock comprises drying the carbonaceous feedstock
to a moisture content of less than about 25, 20, 15, 10 or 9 weight
percent. The carbonaceous feedstock may be dried by any methods
known in the art. In embodiments, a carbonaceous feedstock is dried
by introducing it into one or more dryers 260, as discussed above
with reference to FIG. 4. In embodiments, ground carbonaceous
material exiting grinder 210 is introduced into a grinder discharge
cyclone 220. Within grinder discharge cyclone 220, a stream of
larger sized particles is separated via grinder discharge cyclone
outlet line 225 from a stream of smaller sized particles in grinder
discharge fines outlet line 222. A grinder discharge blower 230 may
introduce the smaller particles separated in grinder discharge
cyclone 220 into one or more dryer baghouse(s) 240. The larger
particles exiting grinder discharge cyclone 220 via grinder
discharge cyclone outlet line 225 are introduced into dryer
260.
[0079] In embodiments, air supplied via air supply fan 261 and line
262 is combined with flue gas in line 570 and introduced into dryer
air heater 280. The flue gas utilized here may be produced during
reforming of the carbonaceous material discussed below. Heat
transfer with steam introduced into the dryer air heater via steam
inlet line 560A/560D produces heated air in heated air line 284 and
condensate in condensate outlet line 282. As discussed hereinabove,
the steam utilized in dryer air heater 280 may be produced via heat
transfer with the hot reformer process gas effluent and/or the
`warm` flue gas effluent, as discussed further hereinbelow.
[0080] Heated air in heated air line 284 may be divided by a heated
air distributor or divider 286 into a plurality of heated air inlet
lines 284A-284C. Within dryer 260, the comminuted carbonaceous
material is dried to a desired moisture content, as mentioned
hereinabove. Dryer effluent comprising air and fines is introduced
via dryer vent line 281 into dryer cyclone 265. Dried carbonaceous
material exits dryer 260 via one or more dried feed lines 294 and
surge hopper 270. Air from reformer feed hopper blower 275 may push
comminuted and dried feed material from dryer 260 and surge hopper
270 along reformer feed hopper inlet line 276 into reformer feed
hopper cyclone 290. Solids removed from dryer cyclone 265 and dryer
baghouse 240 may be introduced into reformer feed hopper inlet line
276, as indicated in FIG. 4.
[0081] Gas exiting dryer cyclone 265 may be combined in grinder
discharge blower outlet line 231 via dryer cyclone fines outlet
line 266 with gas exiting grinder discharge blower 230 and gas
exiting reformer feed hopper cyclone 290 via line 292 and
introduced into dryer baghouse 240. Gases exiting dryer baghouse
via dryer baghouse fines outlet line 244 may pass via dryer exhaust
fan 241 and line 247 to dryer stack 246.
[0082] Dried carbonaceous materials exit reformer feed hopper
cyclone 290 and enter reformer feed hopper 295. Carbonaceous
material from reformer feed hopper 295 is introduced via mixing
vessel rotary feeder 297 and feedstock line 250 into one or more
mixing vessels of mixing apparatus 300.
[0083] Preparing Reformer Feed 620.
[0084] As discussed above, producing synthesis gas via reforming of
carbonaceous material 600 further comprises preparing reformer feed
620. A suitable reformer feed may be formed via combination of
superheated steam and comminuted and dried carbonaceous material
via any methods known in the art. In embodiments, spent catalyst
comprising spent catalyst and associated synthesis gas conversion
product is combined with the carbonaceous material prior to or
along with combination with superheated steam. In embodiments,
preparing reformer feed comprises introducing the comminuted and
dried carbonaceous feed material and superheated steam into one or
more mixing vessels as described hereinabove.
[0085] With reference to FIG. 2, preparing reformer feed material
can comprise introducing comminuted and dried feed material via
lines 250, 250A and 250B into mixing apparatus 300A. Spent
catalyst/conversion product from a catalytic synthesis gas
conversion process may be combined with the carbonaceous material
via line 755. In alternative embodiments, spent catalyst/conversion
product is introduced directly into the mixing vessel(s).
Superheated steam from steam superheater 501B is introduced via
superheated steam lines 550, 550A and 550B into mixers 310A and
310B, respectively.
[0086] With reference to FIG. 3, preparing reformer feed 620 can
comprise introducing comminuted and dried feed material via
feedstock inlet line 250 into mixing apparatus 300B. Superheated
steam from steam superheater 501B' is introduced via superheated
steam line 550 into mixer 310C.
[0087] As mentioned hereinabove, within the mixing apparatus,
superheated steam and carbonaceous material are combined to provide
a reformer feed mixture comprising from about 0.14 kilograms (0.3
pounds) to about 0.32 kilograms (0.7 pounds), from about 0.14 kg
(0.3 pounds) to about 0.23 kg (0.5 pounds) or from about 0.14 kg
(0.3 pounds) to about 0.18 kg (0.4 pounds) of steam per pound of
`dry` feedstock comprising from about 4% to about 20% moisture by
weight, from about 9% to about 18% moisture or from about 10% to
about 20% moisture, to provide the reformer feed mixture that is
introduced into the coiled tubes of the reformer. In embodiments,
the reformer feed comprises from about 0.01 wt % to about 20 wt %,
from about 0.05 wt % to about 10 wt %, or from 1 wt % to about 5 wt
% weight percent spent catalyst/product (e.g. cat/wax). The
reformer feed may have a temperature in the range of from about
150.degree. F. (66.degree. C.) to about 1000.degree. F.
(538.degree. C.), from about 200.degree. F. (93.degree. C.) to
about 750.degree. F. (399.degree. C.), or from about 300.degree. F.
(149.degree. C.) to about 400.degree. F. (204.degree. C.). In
embodiments, the reformer feed has a pressure of at least or about
in the range of from about 34.5 kPa (5 psig) to about 275 kPa (40
psig).
[0088] The superheated steam utilized in the reformer feed mixers
may be produced by heat exchange with the reformer flue gas
effluent and/or the reformer process gas effluent. With reference
to FIG. 2, BFW may be introduced via BFW inlet line(s) 580 into
reformer effluent and reformer flue gas steam generator 501A.
Within reformer effluent and reformer flue gas steam generator
501A, heat transfer between the hot gas (warm' reformer flue gas
passing through steam superheater 501B and `hot` reformer process
gas effluent) and the BFW may produce steam (in steam outlet line
560) having a temperature in the range of from about 300.degree. F.
(148.9.degree. C.) to about 500.degree. F. (260.degree. C.), from
about 350.degree. F. (176.7.degree. C.) to about 500.degree. F.
(260.degree. C.) or from about 350.degree. F. (176.7.degree. C.) to
about 500.degree. F. (260.degree. C.) and a pressure in the range
of from about 200 psig (1379 kPa) to about 300 psig (2068.4 kPa),
from about 250 psig (1723.7 kPa) to about 300 psig (2068.4 kPa), or
from about 275 psig (1896.1 kPa) to about 300 psig (2068.4 kPa).
Steam exiting reformer effluent and reformer flue gas steam
generator 501A via steam generator steam outlet line 560 may be
divided, with a portion entering steam superheater 501B via line
560B and another portion exported via line 560A. Within steam
superheater 501B, heat transfer between `hot` reformer flue gas and
steam produces superheated steam having a temperature in the range
of from about 400.degree. F. (204.4.degree. C.) to about
1000.degree. F. (537.8.degree. C.), from about 600.degree. F.
(315.6.degree. C.) to about 950.degree. F. (510.degree. C.) or from
about 400.degree. F. (204.4.degree. C.) to about 900.degree. F.
(482.2.degree. C.) and/or a pressure in the range of from about 150
psig (1034.2 kPa) to about 400 psig (2757.9 kPa), from about 200
psig (1379 kPa) to about 375 psig (2585.5 kPa) or from about 250
psig (1723.7 kPa) to about 350 psig (2413.2 kPa). The superheated
steam exiting steam superheater 501B is introduced into reformer
feed mixing vessels 310A/310B via lines 550 and 550A/550B.
[0089] With reference to FIG. 3, BFW may be introduced via BFW
inlet line 580 into reformer effluent steam generator 501A'. Within
reformer effluent steam generator 501A', heat transfer between the
hot process gas effluent and the BFW may produce steam. Steam
exiting reformer effluent steam generator 501A' via line 580A may
be introduced into flue gas steam generator 501A''. Within flue gas
steam generator 501A'', heat transfer between `warm` reformer flue
gas and steam produces saturated steam (exiting via steam generator
steam outlet line 560) having a temperature in the range of from
about 300.degree. F. (148.9.degree. C.) to about 500.degree. F.
(260.degree. C.), from about 350.degree. F. (176.7.degree. C.) to
about 500.degree. F. (260.degree. C.) or from about 350.degree. F.
(176.7.degree. C.) to about 500.degree. F. (260.degree. C.) and a
pressure in the range of from about 200 psig (1379 kPa) to about
300 psig (2068.4 kPa), from about 250 psig (1723.7 kPa) to about
300 psig (2068.4 kPa), or from about 275 psig (1896.1 kPa) to about
300 psig (2068.4 kPa).
[0090] Reformer flue gas exiting the reformer via reformer flue gas
outlet line 470 passes through steam superheater 501B', wherein the
temperature of the `hot` flue gas is reduced to a temperature in
the range of from about 530.degree. F. (276.7.degree. C.) to about
1500.degree. F. (815.6.degree. C.), from about 530.degree. F.
(276.7.degree. C.) to about 1200.degree. F. (648.9.degree. C.) or
about 530.degree. F. (276.7.degree. C.) and/or a pressure in the
range of from about -20 inches H.sub.2O to 0 inch H.sub.2O; from
about -15 inch H.sub.2O to about -5 inch H.sub.2O; or from about
-10 inches H.sub.2O to about -5 inches H.sub.2O and superheated
steam is produced. The superheated steam may have a temperature in
the range of from about 400.degree. F. (204.4.degree. C.) to about
1000.degree. F. (537.8.degree. C.), from about 600.degree. F.
(315.6.degree. C.) to about 950.degree. F. (510.degree. C.) or from
about 400.degree. F. (204.4.degree. C.) to about 900.degree. F.
(482.2.degree. C.) and/or a pressure in the range of from about 150
psig (1034.2 kPa) to about 400 psig (2757.9 kPa), from about 200
psig (1379 kPa) to about 375 psig (2585.5 kPa) or from about 250
psig (1723.7 kPa) to about 350 psig (2413.2 kPa). The superheated
steam exiting steam superheater 501B' is introduced into reformer
feed mixing vessel 310C via line 550.
[0091] Reforming Reformer Feed 630.
[0092] As discussed above, producing synthesis gas via reforming of
carbonaceous material 600 further comprises reforming reformer feed
at 630. In embodiments, reforming the reformer feed 630 comprises
converting the reformer feed into synthesis gas via introduction
into a reformer as described above. Reforming of the synthesis gas
will now be described with reference to FIGS. 2 and 3. Reformer
feed is introduced into the reformer via one or more reformer feed
inlet lines 350. In embodiments, a distributor 412 distributes the
reformer feed evenly among a plurality of coiled tubes 410. Within
the coiled tubes, reforming of the carbonaceous feedstock produces
synthesis gas. In embodiments, the temperature of the reformer
(e.g. reformer effluent) is maintained in the range of up to or
about 926.degree. C. (1700.degree. F.), 982.degree. C.
(1800.degree. F.), 1038.degree. C. (1900.degree. F.), 1093.degree.
C. (2000.degree. F.), 1149.degree. C. (2100.degree. F.). In
embodiments, the pressure of the reformer is maintained in the
range of from about 0 psig (0 kPa) to about 100 psig (689.5 kPa),
from about 2 psig (13.8 kPa) to about 60 psig (413.7 kPa) or from
about 5 psig (34.5 kPa) to about 50 psig (344.7 kPa). In
embodiments, the reformer pressure is maintained at a pressure of
equal to or greater than about 2 psig (13.8 kPa), about 5 psig
(34.5 kPa), or about 50 psig (344.7 kPa).
[0093] The heat needed to maintain the desired reformer temperature
is provided to the endothermic reforming process by the combustion
of fuel in one or more burners 404. Air for the combustion may be
heated in air preheater 413 prior to burning with the fuel in
burners 404. The fuel combusted in the burner(s) 404 may be
selected from tailgas (e.g. Fischer-Tropsch tailgas), synthesis
gas, methane (e.g. natural gas), and combinations thereof.
Desirably, at least a portion of the fuel combusted in at least one
of the burner(s) 404 comprises tailgas recycled from a synthesis
gas conversion process. At least one of the burner(s) 404 may be
specially designed for the combustion of tailgas or for the
combustion of tailgas in combination with another gas, for example
in combination with a as selected from synthesis gas and methane
(e.g. natural gas). In embodiments, recycle tailgas in line(s) 770
is introduced into one or more burner(s) 404 by introduction into
one or more of the fuel lines 406 or via another fuel inlet
line(s).
[0094] The synthesis gas produced via this disclosure can be
utilized for the production of a variety of products 710 via
downstream synthesis gas conversion apparatus 700, such as, but not
limited to, liquid Fischer-Tropsch hydrocarbons, alcohols and other
oxidized compounds. As noted hereinabove, such downstream synthesis
gas conversion apparatus may also provide Fischer-Tropsch tailgas
770, spent catalyst/wax 755, or both, at least a portion of which
may be recycled to the mixing apparatus and/or the reformer. As
mentioned hereinabove, for any given feedstock, a desired
composition of the resulting reformer product synthesis gas (i.e.
the proportions of hydrogen, carbon dioxide, carbon monoxide and
methane; the molar ratio of hydrogen to carbon monoxide) can be
provided by adjusting the composition of the dried feedstock (i.e.
the components and/or the moisture content therein), the contact
time in the reformer, the temperature at the reformer outlet, ratio
of steam to carbonaceous material in the reformer feedstock, the
reformer pressure, or any combination of two or more thereof to
provide a suitable synthesis gas for a desired downstream
application.
[0095] In embodiments, the synthesis gas is to be utilized
downstream for the production of liquid hydrocarbons via
Fischer-Tropsch conversion. In embodiments, the synthesis gas is to
be utilized downstream for the production of liquid hydrocarbons
via Fischer-Tropsch conversion with an iron-based catalyst. In such
embodiments, the system may be operated with a reformer exit
temperature in the range of from about 898.degree. C. (1650.degree.
F.) to about 926.degree. C. (1700.degree. F.) and a residence or
contact time that is in the range of from about 0.3 seconds to
about 2.0 seconds in the reformer. The contact or residence time
can be calculated by dividing the internal volume of the reformer
by the flow rate of the process gas exiting the reformer.
[0096] In embodiments, the reformer is configured to provide
temperature, pressure and residence time conditions suitable to
provide a process gas comprising synthesis gas having a desired
molar ratio of H.sub.2 to CO. In embodiments, the reformer is
configured to provide a synthesis gas having a H.sub.2:CO molar
ratio in the range of from about 0.7:1 to about 2:1, from about
0.7:1 to about 1.5:1 or about 1:1. In embodiments, the reformer is
configured to provide a residence time within the reformer in the
range of from about 0.3 s to about 3 s, from about 0.3 s to about 2
s, from about 0.3 s to about 1 s, or from about 0.4 s to about 0.6
s.
[0097] While the preferred embodiments of the invention have been
shown and described, modifications thereof can be made by one
skilled in the art without departing from the spirit and teachings
of the invention. The embodiments described and the examples
provided herein are exemplary only, and are not intended to be
limiting. Many variations and modifications of the invention
disclosed herein are possible and are within the scope of the
invention. Accordingly, the scope of protection is not limited by
the description set out above, but is only limited by the claims
which follow, that scope including all equivalents of the subject
matter of the claims.
[0098] The discussion of a reference is not an admission that it is
prior art to the present invention, especially any reference that
may have a publication date after the priority date of this
application. The disclosures of all patents, patent applications,
and publications cited herein are hereby incorporated herein by
reference in their entirety, to the extent that they provide
exemplary, procedural, or other details supplementary to those set
forth herein.
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