U.S. patent application number 13/890343 was filed with the patent office on 2014-11-13 for methods of and apparatuses for upgrading a hydrocarbon stream including a deoxygenated pyrolysis product.
The applicant listed for this patent is UOP LLC. Invention is credited to Lance Awender Baird, Douglas B. Galloway, Tom N. Kalnes.
Application Number | 20140336427 13/890343 |
Document ID | / |
Family ID | 51865259 |
Filed Date | 2014-11-13 |
United States Patent
Application |
20140336427 |
Kind Code |
A1 |
Baird; Lance Awender ; et
al. |
November 13, 2014 |
METHODS OF AND APPARATUSES FOR UPGRADING A HYDROCARBON STREAM
INCLUDING A DEOXYGENATED PYROLYSIS PRODUCT
Abstract
Methods of and apparatuses for upgrading a hydrocarbon stream
are provided. In an embodiment, a method of upgrading a hydrocarbon
stream includes providing the hydrocarbon stream that includes a
deoxygenated pyrolysis product. The hydrocarbon stream also
includes a residual oxygen-containing compound content. The
residual oxygen-containing compound content of the hydrocarbon
stream is reduced to form an upgraded hydrocarbon stream.
Inventors: |
Baird; Lance Awender;
(Prospect Heights, IL) ; Galloway; Douglas B.;
(Mount Prospect, IL) ; Kalnes; Tom N.; (LaGrange,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
UOP LLC |
Des Plaines |
IL |
US |
|
|
Family ID: |
51865259 |
Appl. No.: |
13/890343 |
Filed: |
May 9, 2013 |
Current U.S.
Class: |
585/240 ;
422/187; 585/833 |
Current CPC
Class: |
C10G 21/00 20130101;
C10G 3/40 20130101; C10G 2300/1011 20130101; C10G 21/28 20130101;
Y02P 30/20 20151101 |
Class at
Publication: |
585/240 ;
585/833; 422/187 |
International
Class: |
C10G 1/00 20060101
C10G001/00 |
Goverment Interests
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0001] This invention was made with Government support under
ZFT-0-40619-01 awarded by the United States Department of Energy.
The Government has certain rights in the invention.
Claims
1. A method of upgrading a hydrocarbon stream, the method
comprising the steps of: providing the hydrocarbon stream
comprising a deoxygenated pyrolysis product, wherein the
hydrocarbon stream comprises a residual oxygen-containing compound
content; and contacting the hydrocarbon stream with a solvent
composition that has a greater affinity for oxygen-containing
compounds over hydrocarbons to reduce the residual
oxygen-containing compound content of the hydrocarbon stream.
2. (canceled)
3. The method of claim 1, wherein contacting the hydrocarbon stream
with the solvent composition comprises contacting the hydrocarbon
stream in a liquid phase with the solvent composition in a liquid
phase, with oxygen-containing compounds transferred from the
hydrocarbon stream to the solvent composition.
4. The method of claim 3, further comprising separating an
oxygenate-rich solvent composition in the liquid phase from the
upgraded hydrocarbon stream in the liquid phase after contacting
the hydrocarbon stream with the solvent composition.
5. The method of claim 4, further comprising regenerating the
oxygenate-rich solvent composition to produce an oxygen-containing
compound stream and a oxygenate-lean solvent stream.
6. The method of claim 5, further comprising separating the
oxygenate-lean solvent stream into a drag stream and a recycle
stream, wherein the recycle stream is combined with fresh solvent
composition and contacts the hydrocarbon stream to reduce the
residual oxygen-containing compound content of the hydrocarbon
stream.
7. The method of claim 1, wherein contacting the hydrocarbon stream
with the solvent composition comprises contacting the hydrocarbon
stream with the solvent composition comprising a basic solvent.
8. The method of claim 1, wherein contacting the hydrocarbon stream
with the solvent composition comprises contacting the hydrocarbon
stream with the solvent composition at a fraction of the solvent
composition to the hydrocarbon stream of from about 2 to about 10%
by volume, based on the total volume of the hydrocarbon stream.
9. The method of claim 1, wherein providing the hydrocarbon stream
comprises pyrolyzing a biomass feed to produce a pyrolysis product
stream.
10. The method of claim 9, wherein pyrolyzing the biomass feed
comprises catalytically pyrolyzing the biomass feed.
11. The method of claim 10, wherein catalytically pyrolyzing the
biomass feed produces an intermediate pyrolysis stream, and wherein
the method further comprises fractionating the intermediate
pyrolysis stream to produce the deoxygenated pyrolysis product.
12. The method of claim 9, wherein pyrolyzing the biomass feed
comprises thermally pyrolyzing the biomass feed.
13. The method of claim 12, further comprising deoxygenating the
pyrolysis product stream to produce the deoxygenated pyrolysis
product.
14. The method of claim 1, wherein providing the hydrocarbon stream
comprises co-processing a pyrolysis product stream and a
petroleum-based source of hydrocarbons to produce the hydrocarbon
stream.
15. A method of upgrading a hydrocarbon stream, the method
comprising the steps of: pyrolyzing a biomass feed to produce a
pyrolysis product stream; contacting the pyrolysis product stream
or a derivative thereof with a solvent composition that has a
greater affinity for oxygen-containing compounds over hydrocarbons;
and separating an oxygenate-rich solvent composition from an
upgraded hydrocarbon stream after contacting the hydrocarbon stream
with the solvent composition.
16. The method of claim 15, wherein contacting the pyrolysis
product stream or the derivative thereof with the solvent
composition comprises contacting the pyrolysis product stream or
the derivative thereof in a liquid phase with the solvent
composition in a liquid phase.
17. An apparatus for upgrading a hydrocarbon stream, the apparatus
comprising: a pyrolysis unit for pyrolyzing a biomass feed to
produce a pyrolysis product stream; optionally, a deoxygenating
unit for receiving the pyrolysis product stream and for
deoxygenating the pyrolysis product stream; an extraction unit,
downstream of the optional deoxygenating unit, for receiving the
hydrocarbon stream comprising a deoxygenated pyrolysis product and
for extracting residual oxygen-containing compounds from the
hydrocarbon stream.
18. The apparatus of claim 17, wherein the pyrolysis unit is
further defined as a catalytic pyrolysis unit, and wherein the
apparatus is free from the deoxygenating unit.
19. The apparatus of claim 17, wherein the pyrolysis unit is
further defined as a thermal pyrolysis unit, and wherein the
deoxygenating unit is present in the apparatus.
20. The apparatus of claim 17, further comprising a co-processing
unit in fluid communication with the extraction unit, upstream of
the extraction unit.
21. The method of claim 15, wherein the pyrolysis product stream or
the derivative thereof is contacted with the solvent composition in
an extraction column, and wherein separating the oxygenate-rich
solvent composition from the upgraded hydrocarbon stream comprises
collecting the oxygenate-rich solvent composition in the extraction
column and removing the oxygenate-rich solvent composition from a
bottom of the extraction column, with the hydrocarbon stream
exiting the extraction column at a top thereof.
Description
TECHNICAL FIELD
[0002] The technical field generally relates to methods of and
apparatuses for upgrading a hydrocarbon stream, and more
particularly relates to methods of and apparatuses for upgrading a
hydrocarbon stream that includes a deoxygenated pyrolysis
product.
BACKGROUND
[0003] Biofuels encompass various types of combustible fuels that
are derived from biomass. Biofuels can be used as combustible fuels
themselves, can be used as an additive component of a combustible
fuels, or can be co-processed with other hydrocarbon sources, such
as a petroleum-based source of hydrocarbons, to produce combustible
fuels. Pyrolysis is a commonly-used process for converting biomass
into biofuel, and pyrolysis can be conducted through either a
thermal process or a catalytic process. In the catalytic pyrolysis
process, the biomass is rapidly heated under an inert atmosphere in
the presence of a catalyst, such as an acid or zeolitic catalyst,
to promote deoxygenation and cracking of pyrolysis vapors into
hydrocarbons and oxygen-containing compounds, such as phenol,
cresol, and alcohols such as C1 to C4 alcohols. Most of the
oxygen-containing compounds can be converted to hydrocarbons during
catalytic pyrolysis to produce a deoxygenated pyrolysis
product.
[0004] Thermal pyrolysis processes include the recently-developed
fast pyrolysis process. Fast pyrolysis is a process during which
biomass is rapidly heated to about 450.degree. C. to about
600.degree. C. in the absence of air using a pyrolysis unit. Under
these conditions, a pyrolysis vapor stream including organic
vapors, water vapor, and pyrolysis gases is produced, along with
char (which includes ash and combustible carbonaceous solids). A
portion of the pyrolysis vapor stream is condensed in a condensing
system to produce a pyrolysis oil stream. Pyrolysis oil is a
complex, highly oxygenated organic liquid that typically contains
about 20-30% by weight water with high acidity (total acid number
(TAN)>150). Because the pyrolysis oil contains high amounts of
oxygen-containing compounds, deoxygenation unit operations may be
employed to remove oxygen-containing compounds from the pyrolysis
oil after fast pyrolysis to thereby form a deoxygenated pyrolysis
product. For example, hydrotreating is a known deoxygenation unit
operation that is commonly used for converting the
oxygen-containing compounds present in the pyrolysis oil to produce
the deoxygenated pyrolysis product.
[0005] Deoxygenated pyrolysis products produced through catalytic
pyrolysis and thermal pyrolysis (after deoxygenation) generally
contain a residual oxygen-containing compound content. While it
would be desirable to use the deoxygenated pyrolysis products in a
transportation fuel such as gasoline or kerosene, even small
amounts of oxygen-containing compounds can be classified as
undesirable contaminants. Hydrotreating of pyrolysis products that
include ethanol also converts the ethanol to ethane, which reduces
the yield of liquid pyrolysis products. Similarly, hydrotreating
can saturate aromatic hydrocarbons, reducing the octane value of
the gasoline fraction and consuming excessive amounts of hydrogen.
Therefore, while hydrotreating of pyrolysis oil may be effective to
remove most of the oxygen-containing compounds from the pyrolysis
oil to produce the deoxygenated pyrolysis products, excessive
hydrotreating is undesirable to reduce the oxygen-containing
compounds to levels that are desirable in gasoline for the
deoxygenated pyrolysis products.
[0006] Accordingly, it is desirable to provide methods of upgrading
a hydrocarbon stream to maximize removal of oxygen-containing
compounds that may be present in the hydrocarbon stream.
Furthermore, other desirable features and characteristics of the
present invention will become apparent from the subsequent detailed
description of the invention and the appended claims, taken in
conjunction with the accompanying drawings and this background of
the invention.
BRIEF SUMMARY
[0007] Methods of and apparatuses for upgrading a hydrocarbon
stream are provided. In an embodiment, a method of upgrading a
hydrocarbon stream includes providing the hydrocarbon stream that
includes a deoxygenated pyrolysis product. The hydrocarbon stream
also includes a residual oxygen-containing compound content. The
hydrocarbon stream that includes the residual oxygen-containing
compound content is contacted with a solvent composition that has a
greater affinity for oxygen-containing compounds over hydrocarbons
to reduce the residual oxygen-containing compound content of the
hydrocarbon stream.
[0008] Another embodiment of a method of upgrading a hydrocarbon
stream includes pyrolyzing a biomass feed to produce a pyrolysis
product stream. The pyrolysis product stream or a derivative
thereof is contacted with a solvent composition that has a greater
affinity for oxygen-containing compounds over hydrocarbons. A spent
solvent composition is separated from an upgraded hydrocarbon
stream after contacting the hydrocarbon stream with the solvent
composition.
[0009] In another embodiment, an apparatus for upgrading a
hydrocarbon stream includes a pyrolysis unit for pyrolyzing a
biomass feed to produce a pyrolysis product stream. The apparatus
optionally includes a deoxygenating unit for receiving the
pyrolysis product stream and for deoxygenating the pyrolysis
product stream. An extraction unit is downstream of the optional
deoxygenating unit for receiving the hydrocarbon stream that
includes a deoxygenated pyrolysis product. The extraction unit
extracts residual oxygen-containing compounds from the hydrocarbon
stream.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The various embodiments will hereinafter be described in
conjunction with the following drawing figures, wherein like
numerals denote like elements, and wherein:
[0011] FIG. 1 is a schematic diagram of an apparatus for and a
method of upgrading a hydrocarbon stream in accordance with an
exemplary embodiment;
[0012] FIG. 2 is a schematic diagram of a catalytic pyrolysis unit
that is included in the apparatus of FIG. 1 in accordance with an
embodiment;
[0013] FIG. 3 is a schematic diagram of an extraction unit that is
included in the apparatus of FIG. 1 in accordance with an
embodiment;
[0014] FIG. 4 is a schematic diagram of an apparatus for and a
method of upgrading a hydrocarbon stream in accordance with another
exemplary embodiment;
[0015] FIG. 5 is a schematic diagram of a thermal pyrolysis unit
that is included in the apparatuses of FIG. 1 or FIG. 4 in
accordance with an embodiment; and
[0016] FIG. 6 is a schematic diagram of an apparatus for and a
method of upgrading a hydrocarbon stream, with the apparatus
including a co-processing unit in accordance with another
embodiment.
DETAILED DESCRIPTION
[0017] The following detailed description is merely exemplary in
nature and is not intended to limit the various embodiments or the
application and uses thereof. Furthermore, there is no intention to
be bound by any theory presented in the preceding background or the
following detailed description.
[0018] Methods of and apparatuses for upgrading a hydrocarbon
stream that includes a deoxygenated pyrolysis product are provided
herein. In accordance with the methods and apparatuses described
herein, the hydrocarbon stream that includes the deoxygenated
pyrolysis product is upgraded to reduce residual oxygen-containing
compound content, if the hydrocarbon stream includes any residual
oxygen-containing compound, through a downstream unit operation
beyond deoxygenation unit operations or intrinsic deoxygenation
that may be employed to yield the deoxygenated pyrolysis product.
As referred to herein, "deoxygenated pyrolysis product" refers to
any component in the hydrocarbon stream that originates from
pyrolysis and that has undergone a unit operation that removes at
least a portion of oxygen-containing compounds therefrom. The
deoxygenated pyrolysis product may be provided as a direct
pyrolysis product stream or a derivative of the pyrolysis product
stream that is obtained after subjecting the pyrolysis product
stream to further unit operations. For example, the deoxygenated
pyrolysis product can be a direct product of pyrolysis (such as
catalytic pyrolysis) or can be a product that results from a
downstream unit operation after pyrolysis, such as for example a
fractionation column that is downstream of the pyrolysis unit or a
deoxygenating unit that is downstream of a thermal pyrolysis unit.
Further, the hydrocarbon stream can be the product of a
co-processing unit operation such as, for example, a fluid
catalytic cracking (FCC) unit operation, within which a pyrolysis
product stream is co-processed or catalytically cracked with
another source of hydrocarbons such as a petroleum-based source of
hydrocarbons. The hydrocarbon stream that includes the deoxygenated
pyrolysis product may be upgraded by contacting the hydrocarbon
stream with a solvent composition that has a greater affinity for
oxygen-containing compounds over hydrocarbons. Contacting the
hydrocarbon stream with the solvent composition is effective to
reduce any residual oxygen-containing compound content of the
hydrocarbon stream without diminishing inherent fuel properties of
the hydrocarbon stream or increasing production costs.
[0019] An embodiment of a method of upgrading a hydrocarbon stream
20 will now be addressed with reference to an exemplary apparatus
10 for upgrading the hydrocarbon stream 20 as shown in FIG. 1, with
further reference to FIGS. 2 and 3 that show additional features of
an exemplary pyrolysis unit 12 and an exemplary extraction unit 14
of the apparatus 10 shown in FIG. 1.
[0020] Referring to FIG. 1, the apparatus 10 includes the pyrolysis
unit 12 and the extraction unit 14. The pyrolysis unit 12 receives
a biomass feed 18 and pyrolyzes the biomass feed 18 to produce a
pyrolysis product stream. In the embodiment of FIG. 1, no
intervening deoxygenating unit is disposed between the pyrolysis
unit 12 and the extraction unit 14, although in other embodiments
and referring momentarily to FIG. 4, a deoxygenating unit 416 may
be disposed between a pyrolysis unit 412 and the extraction unit
14, with the deoxygenating unit 416 in fluid communication with the
pyrolysis unit 412 and the extraction unit 14 and with the
extraction unit 14 downstream of the deoxygenating unit 416. It is
to be appreciated that in other embodiments and although not shown,
the pyrolysis unit may be located at a remote satellite location
from the optional deoxygenation unit and the extraction unit. The
presence or absence of the deoxygenating unit may be dependent upon
the type of pyrolysis unit that is included in the apparatus. In
particular, in the embodiment of FIG. 1 and as shown in further
detail in FIG. 2, the pyrolysis unit 12 is a catalytic pyrolysis
unit 12 and the apparatus 10 is free from a deoxygenating unit
downstream of the pyrolysis unit 12 as described in further detail
below.
[0021] Referring to FIG. 1, the hydrocarbon stream 20 includes a
deoxygenated pyrolysis product. It is to be appreciated that
although the hydrocarbon stream 20 is shown in the Figures to be
produced in accordance with the methods described herein within the
apparatuses described herein, in other embodiments, the hydrocarbon
stream may be provided from a source external to the methods or
apparatuses described herein. The deoxygenated pyrolysis product
may be produced through pyrolysis of a biomass feed 18 in the
pyrolysis unit 12. Suitable biomass feeds 18 include, but are not
limited to, lignocellulosic materials including cellulose,
hemicellulose and lignin or portions thereof, such as short
rotation forestry products, sawmill residues, forest residues, wood
chips, chaff, grains, grasses, agricultural residues such as corn
stover and sugar cane bagasse, weeds, aquatic plants such as whole
algae and lipid extracted algae, hay, recycled and non-recycled
paper and paper products, and any other biogenically-derived
material.
[0022] In accordance with an embodiment and as shown in FIG. 1, the
pyrolysis unit 12 is the catalytic pyrolysis unit 12, which may be
a conventional catalytic pyrolysis unit. In catalytic pyrolysis
units and referring to FIG. 2, the biomass feed 18 is rapidly
heated under an inert atmosphere in the presence of a catalyst 24,
such as an acid or zeolitic catalyst, to promote deoxygenation and
cracking of pyrolysis vapors into hydrocarbons and
oxygen-containing compounds, such as phenol, cresol, and alcohols
such as C1 to C4 alcohols. Most of the oxygen-containing compounds
can be converted to hydrocarbons in the catalytic pyrolysis unit 12
to produce a deoxygenated pyrolysis product. More specifically,
referring to FIG. 2, further details of the catalytic pyrolysis
unit 12 are shown. In particular, as shown in FIG. 2, the catalytic
pyrolysis unit 12 includes a pyrolysis reactor 26 for pyrolyzing
the biomass feed 18, a catalyst regenerator 27 for receiving and
regenerating spent catalyst 29, and a distillation column 32 for
receiving an intermediate pyrolysis stream 33 from the pyrolysis
reactor 26 and for separating various components of the
intermediate pyrolysis stream 33 into separate streams 20, 40, 41,
and 42. In particular, the biomass feed 18 is catalytically
pyrolyzed in the pyrolysis reactor 26 to produce the intermediate
pyrolysis stream 33, and the intermediate pyrolysis stream 33 is
fractionated into the separate streams 20, 40, 41, and 42 by
boiling point in the distillation column. One of the separate
streams that is fractionated by the distillation column 32 is the
deoxygenated pyrolysis product 20, which may also be identified as
a catalytic pyrolysis heavy naptha stream in a conventional
catalytic pyrolysis process flow and which ultimately goes to
gasoline blendstock. Conventional catalytic pyrolysis heavy naphtha
streams are generally characterized by having a gasoline boiling
range such as, e.g., of from about 40 to about 200.degree. C.,
depending upon the environment in which the gasoline blendstock is
to be used. For example, the initial boiling point may be adjusted
up in winter and down in summer and the final boiling point is
adjusted down to meet emission requirements using the reformulated
gasoline model. The deoxygenated pyrolysis product 20 is generally
depleted of most oxygen-containing compounds that are present in
the intermediate pyrolysis stream 33, although the deoxygenated
pyrolysis product 20 may have a residual oxygen-containing compound
content. For example, the deoxygenated pyrolysis product 20 may
have a residual oxygen-containing compound content of less than
about 15 weight %, such as from about 0.01 to about 10 weight %,
such as from about 1 to about 3 weight %, based on the total weight
of the deoxygenated pyrolysis product 20. Residual
oxygen-containing compounds that may be present in the deoxygenated
pyrolysis product include, but are not limited to, ketones,
carboxylic acids, aldehydes, esters, phenols, furans, and
multi-oxygenated compounds. Because the deoxygenated pyrolysis
product 20 is depleted of most oxygen-containing compounds, in an
embodiment and as shown in FIG. 1, the apparatus 10 is free from
the deoxygenating unit. In this embodiment, the deoxygenated
pyrolysis product 20 is provided as the hydrocarbon stream 20 for
further downstream processing, as described in further detail
below.
[0023] Referring back to FIG. 1, in accordance with the exemplary
method, the residual oxygen-containing compound content of the
hydrocarbon stream 20 is contacted with a solvent composition 44
that has a greater affinity for oxygen-containing compounds over
hydrocarbons. The hydrocarbon stream 20 may be contacted with the
solvent composition 44 through various unit operations that are
known to separate oxygen-containing compounds from a hydrocarbon
stream 20. By "greater affinity", it is meant that when the solvent
composition 44 and the hydrocarbon stream 20 are in contact with
each other at equilibrium, the concentration of oxygen-containing
compounds in the solvent 44 is much higher than their concentration
in the hydrocarbon stream 20. In embodiments, the solvent
composition 44 has a higher density than the hydrocarbon stream 20
to enable liquid/liquid extraction techniques to be employed as
described in further detail below. Suitable solvent compositions 44
that may be employed to contact the hydrocarbon stream 20 include,
but are not limited to, basic solvents and/or organic solvents.
Examples of suitable solvent compositions 44 include, but are not
limited to, water made basic by addition of a basic compound such
as ammonia, soda ash, or the like; sulfolane; glycols such as
triethylene glycol; N-methylpyrrolidone; and combinations thereof.
Water made basic by addition of ammonia and/or soda ash is
selective toward removal of phenol and, thus, serves as a
particular suitable solvent composition 44.
[0024] Because oxygen-containing compounds to be removed from the
hydrocarbon stream 20 are only present in residual amounts,
relatively small amounts of the solvent composition 44 compared to
the amount of the hydrocarbon stream 20 are required to effectively
reduce the residual oxygen-containing compound content of the
hydrocarbon stream 20. In an embodiment, the hydrocarbon stream 20
is contacted with the solvent composition 44 at a fraction of the
solvent composition 44 to the hydrocarbon stream 20 of from about 2
to about 10% by volume, such as from about 2 to about 6% by volume,
based on the total volume of the hydrocarbon stream 20. Such low
amounts of the solvent composition 44 to the hydrocarbon stream 20
are particularly suitable when the extraction unit is a mercaptan
extraction unit, such as a Merox.TM. extraction unit commercially
available from UOP LLC. Alternatively, in other embodiments and
depending upon the type of extraction unit that is employed, the
amount of residual oxygen-containing compounds in the hydrocarbon
stream 20, and the selectivity of the solvent composition 44,
higher fractions of the solvent composition 44 to the hydrocarbon
stream 20 may be employed such as a fraction of the solvent
composition 44 to the hydrocarbon stream 20 of up to 1000% by
volume, such as up to about 500% by volume, based on the total
volume of the hydrocarbon stream 20.
[0025] In an embodiment and as shown in FIG. 1, the apparatus 10
includes the extraction unit 14 to facilitate contact of the
hydrocarbon stream 20 with the solvent composition 44. In the
embodiment shown in FIG. 1, the extraction unit 14 is in fluid
communication with the pyrolysis unit 12 for receiving the
hydrocarbon stream 20 and for extracting residual oxygen-containing
compounds from the hydrocarbon stream 20. Although not shown in
FIG. 1, it is to be appreciated that intervening units may be
disposed upstream of the extraction unit 14, between the pyrolysis
unit 12 and the extraction unit 14, to further process the
pyrolysis product in accordance with conventional techniques. It is
also to be appreciated that the pyrolysis unit and the extraction
unit need not necessarily be in fluid communication.
[0026] In an embodiment, the hydrocarbon stream 20 is in a liquid
phase when contacted with solvent composition 44 in a liquid phase,
with oxygen-containing compounds transferred from the hydrocarbon
stream 20 to the solvent composition 44. However, an alternative
embodiment with the hydrocarbon stream 20 as a gas is also
feasible, though the higher temperature required makes it a less
attractive option. Referring to FIG. 3, further details of an
exemplary extraction unit 14 are shown in accordance with an
embodiment. In this embodiment, the extraction unit 14 includes an
extraction column 48, a solvent fractionation column 50 in fluid
communication with the extraction column 48 for receiving
oxygenate-rich solvent composition 52, and a condenser 54 in fluid
communication with the solvent fractionation column 50 for
receiving an oxygenate-lean solvent stream 56. In this embodiment,
the extraction unit 14 provides for recovery of the oxygenate-rich
solvent composition 52 for further use within the extraction unit
14. The extraction column 48 may facilitate liquid/liquid contact
and, in an embodiment, is specifically designed for a low flow rate
of the solvent composition 44. During operation, the hydrocarbon
stream 20 is introduced into the extraction column 48 in liquid
phase and the solvent composition 44 is introduced into the
extraction column 48 in liquid phase, with the hydrocarbon stream
20 introduced into a bottom of the extraction column 48 and the
solvent composition 44 introduced into a top of the extraction
column 48. In an exemplary embodiment and as shown in FIG. 3, the
extraction column 48 includes a series of trays 55 that each
include a weir 57 that is adapted to receive the solvent
composition 44 from higher trays 55, with downcomers 58 extending
from a weir 57 of higher trays 55 to a weir 57 of the immediately
adjacent lower trays 55 and with the weirs 57 providing a
sufficient depth to maintain a level of the solvent composition 44
sufficiently high to seal the downcomers 58 that lead thereinto.
The weirs 57 maintain a deep layer (e.g., about 30 cm) of the
solvent composition 44 on the trays 55 to ensure adequate
liquid/liquid contact between the solvent composition 44 and the
hydrocarbon stream 20 in each stage. The weirs 57 seal the
downcomers 58 to prevent the hydrocarbon stream 20, which is less
dense than the solvent composition 44 in this embodiment, from
entering the downcomers 58. In embodiments, the downcomers 58 may
be pipes, although at higher solvent composition 44 to hydrocarbon
stream 20 flow rates, the downcomers 58 may be conventional chordal
baffles instead of pipes. Each tray 55 also includes a perforated
jet deck 61 that enables the hydrocarbon stream 20 in liquid form
to flow up the extraction column 48, through the trays 55. The
perforated jet deck 61 has perforations that are sufficiently small
to avoid weeping of the solvent composition 44 in the trays 55
through the perforations during operation of the extraction column
48.
[0027] In accordance with an embodiment, an oxygenate-rich solvent
composition 52 is separated in the liquid phase from an upgraded
hydrocarbon stream 21 in the liquid phase after contacting the
hydrocarbon stream 20 with the solvent composition 44. For example,
as shown in FIG. 3, the oxygenate-rich solvent composition 52 may
be collected in the extraction column 48 and removed from a bottom
of the extraction column 48, while the hydrocarbon stream 20 that
is passed through the trays 55 of the extraction column 48 becomes
upgraded through the contact with the solvent composition 44 and
exits the extraction column 48 at a top thereof. The upgraded
hydrocarbon stream 21 may be used as transportation fuel, or may be
subject to further unit operations in accordance with conventional
hydrocarbon refinement. The oxygenate-rich solvent composition 52
may be regenerated to produce an oxygen-containing compound stream
63 and the oxygenate-lean solvent stream 56. For example, in an
embodiment and as shown in FIG. 3, the oxygenate-rich solvent
composition 52 is introduced into the solvent fractionation column
50, which fractionates the oxygenate-rich solvent composition 52
into the oxygenate-lean solvent stream 56 in vapor form and the
oxygen-containing compound stream 63 in liquid form. The
oxygen-containing compound stream 63 is expelled to waste,
remediation, or recovery of the oxygen-containing compounds
therein. The oxygenate-lean solvent stream 56 in vapor form is
passed to the condenser 54 to condense the oxygenate-lean solvent
stream 56 into liquid form. However and although not shown, it is
to be appreciated that in other embodiments, a higher boiling
solvent composition could be used, in which case the
oxygenate-containing compound stream would be recovered overhead
and the oxygenate-lean solvent stream would be recovered from the
bottom of the condenser. In an embodiment, some oxygen-containing
compounds may remain in the oxygenate-lean solvent stream 56 and,
to avoid buildup within the extraction unit 14, the oxygenate-lean
solvent stream 56 is separated into a drag stream 69 and a recycle
stream 71. The recycle stream 71 is combined with fresh solvent
composition 73 and returned to the extraction column 48.
[0028] In another embodiment and although not shown, it is to be
appreciated that the extraction unit may only include the
extraction column, without the further features that provide for
recovery of the solvent composition. In this embodiment, the
oxygenate-rich solvent composition may be expelled to waste or
remediation without recovery of the solvent composition.
[0029] Another embodiment of a method of upgrading a hydrocarbon
stream will now be addressed with reference to an exemplary
apparatus 410 for upgrading the hydrocarbon stream 420 as shown in
FIG. 4, with further reference to FIG. 5 that shows additional
features of an exemplary pyrolysis unit 412 of the apparatus 410
shown in FIG. 4. Referring to FIG. 4 and as alluded to above, in an
embodiment the apparatus 410 includes the pyrolysis unit 412, the
deoxygenating unit 416, and the extraction unit 14 that is in fluid
communication with the pyrolysis unit 412. In this embodiment, the
pyrolysis unit 412 is a thermal pyrolysis unit 412 and produces
pyrolysis oil 433, which is highly oxygenated. Conversely, the
catalytic pyrolysis unit 12 of the embodiment shown in FIG. 1
produces deoxygenated pyrolysis products 20. The deoxygenating unit
416 may be disposed between the pyrolysis unit 412 and the
extraction unit 14 to remove most oxygen-containing compounds from
the pyrolysis oil 433 before introducing into the extraction unit
14, with the deoxygenating unit 416 in fluid communication with the
pyrolysis unit 412 and the extraction unit 14 and with the
extraction unit 14 downstream of the deoxygenating unit 416. The
extraction unit 14 in this embodiment may be the same as described
above.
[0030] Referring to FIG. 4, the hydrocarbon stream 420 includes a
deoxygenated pyrolysis product. In this embodiment, the
deoxygenated pyrolysis product may be produced through thermal
pyrolysis of a biomass feed 18, such as in the thermal pyrolysis
unit 412. In this embodiment, thermal pyrolysis produces the
pyrolysis product stream 433, which is pyrolysis oil 433. The
pyrolysis product stream 433 is then deoxygenated in the
deoxygenating unit 416. Suitable biomass feeds 18 include those
described above.
[0031] In accordance with an embodiment and as shown in detail in
FIG. 5, the thermal pyrolysis unit 412 may be a fast thermal
pyrolysis unit 412. In this embodiment, the pyrolysis unit 412
includes a hopper or feed bin 78 for receiving the biomass feed 18.
The hopper 78 is in communication with a reactor feed chamber 80
formed by, for example, an auger, a screw feed device, a conveyor,
or other batch feed device. The reactor feed chamber 80 is further
selectively connected to a thermal conversion or pyrolysis reactor
426 that is configured to thermally convert or pyrolyze the biomass
feed 18. The thermal conversion reactor 426 includes a biomass
inlet 82 for receiving the biomass feed 18 from the reactor feed
chamber 80. Further, the thermal conversion reactor 426 includes a
carrier gas inlet 84 for receiving a carrier gas 86. The thermal
conversion reactor 426 may also include a solid heat transfer
medium inlet 88 to receive hot heat transfer medium 90, such as
sand, catalyst, or other inert particulate. Alternatively and
although not shown, the heat transfer medium 90 may be mixed with
and carried by the carrier gas 86 through the carrier gas inlet
84.
[0032] As the biomass feed 18 is heated by the heat transfer medium
90 to a thermal conversion or pyrolysis temperature, typically
about 500.degree. C., the thermal conversion or pyrolysis reaction
occurs and pyrolysis vapor 92 and char are formed in the thermal
conversion reactor 426. The pyrolysis vapor 92 and char, along with
the heat transfer medium 90, are carried out of an outlet 96 in the
thermal conversion reactor 426 and through a line 98 to a separator
100, such as, for example, a cyclone. The separator 100 separates
the pyrolysis vapor 92 from the char and heat transfer medium 94.
As shown, the pyrolysis vapor 92 is directed to a pyrolysis
condenser 72 which condenses the pyrolysis vapor 92 to form the
pyrolysis oil 433. Uncondensed gas 86 exits the pyrolysis condenser
72, a portion of the uncondensed gas 86 may be recycled as the
carrier gas 86, and a portion of the uncondensed gas 86 may be
taken as net gas product 85. The net gas product 85 may be burned
to dry the biomass feed 18 or used as a combustion fuel to generate
electricity.
[0033] The char and heat transfer medium 94 are fed to a combustion
unit 102, typically referred to as a reheater, for the purpose of
reheating the heat transfer medium 90. As shown, a blower 104 feeds
air or another oxygen-containing gas 106 into the combustion unit
102. Upon contact with the oxygen, the char combusts, heating the
heat transfer medium 90 and forming flue gas and ash 108. The hot
heat transfer medium 90 exits the combustion unit 102 and is
returned to the thermal conversion reactor 426. The flue gas and
ash 108 exit the combustion unit 102 and are directed to a flue gas
separator 110, such as a cyclone. The flue gas separator 110
separates the ash 112 and the flue gas 114, which can be disposed
of.
[0034] The pyrolysis product stream from the pyrolysis unit 412,
for purposes of this embodiment, is the pyrolysis oil 433. Because
the pyrolysis oil 433 is highly oxygenated coming from the thermal
pyrolysis unit 412, the pyrolysis product stream 433 is
deoxygenated to produce the deoxygenated pyrolysis product 420. One
example of a suitable technique for deoxygenating the pyrolysis
product stream 433 is hydrotreating, which reduces the
oxygen-containing compound content of the pyrolysis product stream
433 thereby producing the deoxygenated pyrolysis product 420. The
deoxygenated pyrolysis product 420 generally has a residual
oxygen-containing compound content, which is less than the original
oxygen-containing compound content of the pyrolysis product stream
433. In an embodiment and as shown in FIG. 4, the pyrolysis product
stream 433 is deoxygenated within the deoxygenating unit 416, which
may be a hydrotreating unit. Generally, the pyrolysis product
stream 433 is in a liquid state and is introduced into the
deoxygenating unit 416, which includes a hydrotreating reactor (not
shown) having a hydrotreating catalyst bed. In embodiments, the
hydrotreating reactor may be a continuous flow reactor, such as a
fixed-bed reactor, a continuous stirred tank reactor (CSTR), a
trickle bed reactor, an ebulliating bed reactor, a slurry reactor,
or any other reactor known to those skilled in the art for
hydroprocessing. Conditions for effectuating hydrotreating are
known in the art. Deoxygenating produces the deoxygenated pyrolysis
product 420 and an oxygen-containing compound stream 435. In this
embodiment, the deoxygenated pyrolysis product 420 is provided as
the hydrocarbon stream 420 for further downstream processing.
[0035] In accordance with the exemplary method, the residual
oxygen-containing compound content of the hydrocarbon stream 420 is
contacted with the solvent composition 44. In particular, as
described above, the hydrocarbon stream 420 may be contacted with
the solvent composition 44 as described above to produce the
upgraded hydrocarbon stream 421, with the extraction unit 14 being
the same as described above.
[0036] In another embodiment of a method of upgrading a hydrocarbon
stream 620, the hydrocarbon stream 620 is provided by co-processing
a pyrolysis product stream 633 and a petroleum-based source of
hydrocarbons 637 to produce the hydrocarbon stream 620, as
illustrated in FIG. 6. For example, the exemplary method of this
embodiment may be conducted in an apparatus 610 that is similar to
the apparatuses 10, 410 shown in FIGS. 1 and 4, respectively, but
that includes a co-processing unit 613 that is in fluid
communication with the pyrolysis unit 612 and the extraction unit
14 and is downstream of the pyrolysis unit 612 and upstream of the
extraction unit 14. Referring to FIG. 6, co-processing the
pyrolysis product stream 633 and the petroleum-based source of
hydrocarbons 637 is conducted by catalytically cracking a mixture
646 of the pyrolysis product stream 633 and the petroleum-based
source of hydrocarbons 637 in the presence of a particulate
cracking catalyst 630.
[0037] Catalytic cracking can be conducted in any manner known in
the art for co-processing pyrolysis product streams and
petroleum-based sources of hydrocarbons 637, such as in a fluid
catalytic cracking (FCC) unit. By way of example and as shown in
FIG. 6, an exemplary co-processing unit 613 includes a vertical
conduit or riser 628. The petroleum-based source of hydrocarbons
637 is introduced into the riser 628 from a hydrocarbon outlet 638
and the particulate cracking catalyst 630 may be introduced into
the riser 628 at a catalyst outlet 631 that is downstream of the
hydrocarbon outlet 638 but upstream of a pyrolysis product outlet
636. However, it is to be appreciated that the methods described
herein are not particularly limited to the relative locations of
the hydrocarbon outlet 638, the catalyst outlet 631, and the
pyrolysis product outlet 636. The residence time of the particulate
cracking catalyst 630 and the mixture 646 of the pyrolysis product
stream 633 and the petroleum-based source of hydrocarbons 637 in
the riser 628 is generally only a few seconds. General operating
conditions within the riser 628 in co-processing units 613 are
known in the art, e.g., a reaction temperature is generally from
about 510 to about 565.degree. C., reaction pressure of about 135
to about 280 kPa, and a ratio of catalyst to the mixture 646 of the
pyrolysis product stream 633 and the petroleum-based source of
hydrocarbons 637 of from about 4:1 to about 12:1.
[0038] Catalytic cracking of the mixture 646 of the pyrolysis
product stream 633 and the petroleum-based source of hydrocarbons
637 produces an effluent 659 that includes spent particulate
cracking catalyst 676 and a gaseous component 661. The gaseous
component 661 includes products from the reaction in the riser 628
such as cracked hydrocarbons. In accordance with an embodiment of
the contemplated method, the spent particulate cracking catalyst
676 and the gaseous component 661 are separated. In this
embodiment, and as shown in FIG. 6, the co-processing unit 613
further includes a containment vessel 662 that separates the spent
particulate cracking catalyst 676 from the effluent 659. The
gaseous component 661 of the effluent 659 is separated from the
spent particulate cracking catalyst 676 in the separator vessel
662, and the gaseous component 661 may be vented from the separator
vessel 662 via a product line 660. Various separation schemes are
known in the art for separating the spent particulate catalyst 676
and the gaseous component 661. In an embodiment, bulk separation is
accomplished by passing the effluent 659 through a tee disengage
647, followed by passing the effluent through a primary cyclone 649
and secondary cyclone 651 to complete the separation. Although
multiple sets of cyclones are generally used, only one set of the
primary cyclone 649 and the secondary cyclone 651 is shown. The
spent particulate cracking catalyst 676 falls downward to a
stripper 668, where stripping steam 645 is introduced and combined
with the spent particulate cracking catalyst 676. A catalyst
regenerator 670 is in fluid communication with the separator vessel
662 and with the riser 628. The spent particulate cracking catalyst
676 that is separated from the gaseous component 661 is introduced
into the catalyst regenerator 670 from the stripper 668, and coke
is removed from the spent particulate cracking catalyst 676 in the
catalyst regenerator 670. The catalyst regenerator 670 passes
regenerated particulate catalyst 630 to the riser 628.
[0039] It is to be appreciated that, although not shown in FIG. 6,
the deoxygenating unit may be included in the apparatus 610 of FIG.
6, either upstream or downstream of the co-processing unit. It is
also to be appreciated that in embodiments, no deoxygenating unit
is necessary for the apparatus 610 of FIG. 6. The gaseous component
661 may be condensed in a condenser 664 and introduced into a
distillation column 632, where distillation may be conducted in the
same manner as described above in the context of the embodiment
shown in FIG. 2 to provide the hydrocarbon stream 620 that is
ultimately passed to the extraction unit 14.
[0040] While at least one exemplary embodiment has been presented
in the foregoing detailed description of the invention, it should
be appreciated that a vast number of variations exist. It should
also be appreciated that the exemplary embodiment or exemplary
embodiments are only examples, and are not intended to limit the
scope, applicability, or configuration of the invention in any way.
Rather, the foregoing detailed description will provide those
skilled in the art with a convenient road map for implementing an
exemplary embodiment of the invention. It being understood that
various changes may be made in the function and arrangement of
elements described in an exemplary embodiment without departing
from the scope of the invention as set forth in the appended
claims.
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