U.S. patent application number 12/555184 was filed with the patent office on 2009-12-31 for methods and systems for biomass conversion to carboxylic acids and alcohols.
This patent application is currently assigned to The Texas A&M university System. Invention is credited to Richard Davison, Mark Thomas Holtzapple.
Application Number | 20090325251 12/555184 |
Document ID | / |
Family ID | 35784325 |
Filed Date | 2009-12-31 |
United States Patent
Application |
20090325251 |
Kind Code |
A1 |
Holtzapple; Mark Thomas ; et
al. |
December 31, 2009 |
Methods and Systems for Biomass Conversion to Carboxylic Acids and
Alcohols
Abstract
The disclosure includes a method, process and apparatus for the
conversion of biomass to carboxylic acids and/or primary alcohols.
The system may include a pretreatment/fermentation subsystem
operable to produce a fermentation broth containing carboxylic acid
salts from biomass, such as lignocellulosic biomass. The system may
also include a dewatering subsystem operable to remove excess water
from the fermentation broth to produce a concentrated product. The
system may also includes an acid springing subsystem operable to
produce a mixed carboxylic acid product. The system may also
include a hydrogenation subsystem operable to produce an alcohol
mixture, such as a mixture containing primary alcohols. Methods of
operating this system or other systems to obtain a carboxylic acid
or alcohol mixture are also provided.
Inventors: |
Holtzapple; Mark Thomas;
(College station, TX) ; Davison; Richard; (Bryan,
TX) |
Correspondence
Address: |
BAKER BOTTS L.L.P.
2001 ROSS AVENUE, SUITE 600
DALLAS
TX
75201-2980
US
|
Assignee: |
The Texas A&M university
System
College Station
TX
|
Family ID: |
35784325 |
Appl. No.: |
12/555184 |
Filed: |
September 8, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11153978 |
Jun 16, 2005 |
|
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12555184 |
|
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60580291 |
Jun 16, 2004 |
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Current U.S.
Class: |
435/157 ;
435/289.1 |
Current CPC
Class: |
C12M 29/02 20130101;
Y02E 50/17 20130101; C12M 47/00 20130101; C12P 7/40 20130101; C12M
45/06 20130101; C12P 7/02 20130101; Y02E 50/10 20130101; C12P 7/10
20130101; C07C 29/149 20130101; C12M 21/12 20130101; C12M 21/16
20130101; C12M 43/02 20130101; Y02E 50/16 20130101; C07C 29/149
20130101; C07C 31/125 20130101 |
Class at
Publication: |
435/157 ;
435/289.1 |
International
Class: |
C12P 7/04 20060101
C12P007/04; C12M 1/00 20060101 C12M001/00 |
Claims
1. A system for the conversion of biomass comprising: a
pretreatment/fermentation subsystem operable to: pretreat biomass
with lime or quick lime and air to produce treated biomass; and
ferment the treated biomass with an inoculum to produce a
fermentation broth containing carboxylic acid salts; a dewatering
subsystem operable to: remove excess water from the fermentation
broth to produce a concentrated product; and an acid springing
subsystem operable to: combine the concentrated product with a
low-molecular-weight tertiary amine or ammonia to produce a
low-molecular-weight tertiary amine or ammonia carboxylate product
from the carboxylic acid salts; replace the low-molecular-weight
tertiary amine or ammonia in the low-molecular-weight tertiary
amine or ammonia carboxylate product with a high-molecular-weight
tertiary amine to form a high-molecular-weight tertiary amine
carboxylate product; and thermally break the amine-carboxylate
bonds in the high-molecular-weight tertiary amine carboxylate
product to produce a mixed carboxylic acid product.
2. A system according to claim 1, further comprising a
hydrogenation sub system operable to: combine the mixed carboxylic
acid produce with a high-molecular-weight alcohol to form an ester;
convert the ester to an alcohol mixture using a hydrogenation
catalyst; and separate the alcohol mixture from the
high-molecular-weight alcohol.
3. A system according to claim 1, where the biomass comprises
lignocellulosic biomass.
4. A system according to claim 1, wherein the
pretreatment/fermentation subsystem further comprises: a pit
having: a liner; gravel placed on the liner; and a perforated drain
pipe embedded in the gravel; a biomass pile located on top of the
pit; a cover over the biomass pile; and a pump operable to
circulate water from the pit to the top of the biomass pile.
5. A system according to claim 4, wherein the
pretreatment/fermentation subsystem further comprises: a blower
operable to circulate air through the biomass pile; and a lime
water slurry operable to remove carbon dioxide from the air.
6. A system according to claim 1, wherein the inoculum comprises a
salt-tolerant microorganism.
7. A system according to claim 1, wherein the dewatering subsystem
further comprises: a high-molecular-weight carboxylic acid added to
the fermentation broth to produce acidified fermentation broth; and
an evaporator operable to concentrate the acidified fermentation
broth.
8. A system according to claim 7, wherein the high-molecular-weight
carboxylic acid comprises caproic acid, valeic acid or hepotanoic
acid.
9. A system according to claim 1, wherein the acid springing
subsystem further comprises: a mixer to operable to mix the
concentrated product with the low-molecular-weight tertiary amine
or ammonia and carbon dioxide; a column operable to exchange the
low-molecular-weight tertiary amine or ammonia in the
low-molecular-weight tertiary amine or ammonia carboxylate product
for a high-molecular-weight tertiary amine; and a column operable
to thermally break the amine-carboxylate bonds in the
high-molecular-weight tertiary amine carboxylate product to produce
a mixed carboxylic acid product.
10. A system according to claim 1, wherein the low-molecular-weight
tertiary amine comprises triethyl amine.
11. A system according to claim 1, wherein the
high-molecular-weight tertiary amine comprises trioctyl amine or
triethanol amine.
12. A system according to claim 2, wherein the hydrogenation
subsystem further comprises: a column operable to combine the mixed
carboxylic acid produce with a high-molecular-weight alcohol to
form an ester; a hydrogenation reactor operable to convert the
ester to an alcohol mixture using a hydrogenation catalyst; and a
column operable to separate the alcohol mixture from the
high-molecular-weight alcohol.
13. A system according to claim 2, wherein the
high-molecular-weight alcohol comprises heptanol.
14. A system according to claim 2, wherein the alcohol mixture
substantially comprises primary alcohols.
15. A system according to claim 1, further comprising the system
operable to recycle process heat within at least one subsystem or
from one subsystem to another.
16. A system according to claim 1, further comprising the system
operable to recycle water within at least one subsystem or from one
subsystem to another.
17. A system according to claim 1, further comprising the system
operable to recycle lime or quick lime within at least one
subsystem or from one subsystem to another.
18. A system for the conversion of biomass comprising: a
pretreatment/fermentation means operable to: pretreat biomass with
lime or quick lime and air to produce treated biomass; and ferment
the treated biomass with an inoculum to produce a fermentation
broth containing carboxylic acid salts; a dewatering means operable
to: remove excess water from the fermentation broth to produce a
concentrated product; and an acid springing means operable to:
combine the concentrated product with a low-molecular-weight
tertiary amine or ammonia to produce a low-molecular-weight
tertiary amine or ammonia carboxylate product from the carboxylic
acid salts; replace the low-molecular-weight tertiary amine or
ammonia in the low-molecular-weight tertiary amine or ammonia
carboxylate product with a high-molecular-weight tertiary amine to
form a high-molecular-weight tertiary amine carboxylate product;
and thermally break the amine-carboxylate bonds in the
high-molecular-weight tertiary amine carboxylate product to produce
a mixed carboxylic acid product.
19. A system according to claim 18, further comprising a
hydrogenation means operable to: combine the mixed carboxylic acid
produce with a high-molecular-weight alcohol to form an ester;
convert the ester to an alcohol mixture using a hydrogenation
catalyst; and separate the alcohol mixture from the
high-molecular-weight alcohol.
20. (canceled)
21. A method of obtaining a fermentation product comprising:
treating a pile of biomass with lime or quick lime, water, an
inoculum and air to produce a fermentation broth, acidifying the
fermentation broth with a high-molecular-weight carboxyllic acid to
produce acidified fermentation broth; stripping the fermentation
broth in a stripping column to produce stripped fermentation broth;
concentrating the stripped fermentation broth in an evaporator to
produce concentrated product; mixing the concentrated product with
a low-molecular-weight tertiary amine or ammonia and carbon dioxide
to produce a low-molecular-weight tertiary amine or ammonia
carboxylate; exchanging the low-molecular-weight tertiary amine or
ammonia carboxylate with a high-molecular-weight tertiary amine to
produce a high-molecular-weight tertiary amine carboxylate; heating
the high-molecular-weight tertiary amine carboxylate to a
temperature sufficient to break acid/amine bonds to produce a free
carboxylic acid product; and recovering the free carboxylic acid
product; further comprising: combining the carboxylic acid produce
with a high-molecular-weight alcohol to from an ester;
hydrogenating the ester to form an alcohol product; separating the
high-molecular-weight alcohol from the alcohol product; and
recovering the alcohol product.
22. (canceled)
23. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. Ser. No. 11/153,978
filed Jun. 16, 2005 and claims priority to U.S. Provisional
Application No. 60/580,291 filed Jun. 16, 2004.
TECHNICAL FIELD
[0002] The present invention relates to methods of converting
biomass to useful substances, such as carboxylic acids and primary
alcohols, through an integrated pretreatment, fermentation,
dewatering and treatment process. More specifically it may relate
to a method applied to lignocellulosic biomass.
BACKGROUND
[0003] A great deal of biomass, particularly lignocellulosic
biomass, remains unused or inefficiently used during agricultural
and industrial processes. Disposal of this biomass is often
difficult or costly. Therefore, methods of using this biomass to
produce useful chemicals are quite valuable.
[0004] Organic acids are important chemicals of commerce.
Historically, organic acids were produced from animal fat or
vegetable oil sources or from petroleum sources in substantially
nonaqueous systems. More recently, organic acids have been
identified as among the most attractive products for manufacture
from biomass by fermentation. Alcohols are also important
industrial chemicals that may be produced by fermentation of
biomass. However, extraction of organic acids and alcohols from the
overall fermentation product is not easy and is often inefficient
in the use of energy, water and reactant chemicals.
SUMMARY OF THE INVENTION
[0005] The present invention includes a method, process and
apparatus for the conversion of biomass to carboxylic acids and/or
primary alcohols.
[0006] According to another embodiment, the invention includes a
method of obtaining a fermentation product. The method may include:
treating a pile of biomass with lime or quick lime, water, an
inoculum and air to produce a fermentation broth; acidifying the
fermentation broth with a high-molecular-weight carboxyllic acid to
produce acidified fermentation broth; stripping the fermentation
broth in a stripping column to produce stripped fermentation broth;
concentrating the stripped fermentation broth in an evaporator to
produce concentrated product; mixing the con centrated product with
a low-molecular-weight tertiary amine or ammonia and carbon dioxide
to produce a low-molecular-weight tertiary amine or ammonia
carboxylate; exchanging the low-molecular-weight tertiary amine or
ammonia carboxylate with a high-molecular-weight tertiary amine to
produce a high-molecular-weight tertiary amine carboxylate; heating
the high-molecular-weight tertiary amine carboxylate to a
temperature sufficient to break acid/amine bonds to produce a free
carboxylic acid product; and recovering the free carboxylic acid
product.
[0007] In a more specific embodiment the system may also include a
hydrogenation subsystem operable to combine the mixed carboxylic
acid produce with a high-molecular-weight alcohol to form an ester,
convert the ester to an alcohol mixture using a hydrogenation
catalyst, and separate the alcohol mixture from the
high-molecular-weight alcohol.
[0008] According to another embodiment, the invention includes a
method of obtaining a fermentation product. The method may include:
treating a pile of biomass with lime or quick lime, water, an
inoculum and air to produce a fermentation broth; acidifying the
fermentation broth with a high-molecular-weight carboxyllic acid to
produce acidified fermentation broth; stripping the fermentation
broth in a stripping column to produce stripped fermentation broth;
concentrating the stripped fermentation broth in an evaporator to
produce concentrated product; mixing the concentrated product with
a low-molecular-weight tertiary amine or ammonia and carbon dioxide
to produce a low-molecular-weight tertiary amine or ammonia
carboxylate; exchanging the low-molecular-weight tertiary amine or
ammonia carboxylate with a high-molecular-weight tertiary amine to
produce a high-molecular-weight tertiary amine carboxylate; heating
the high-molecular-weight tertiary amine carboxylate to a
temperature sufficient to break acid/amine bonds to produce a free
carboxylic acid product; and recovering the free carboxylic acid
product.
[0009] In a more specific embodiment, the method may also include:
combining the carboxylic acid produce with a high-molecular-weight
alcohol to from an ester; hydrogenating the ester to form an
alcohol product; separating the high-molecular-weight alcohol from
the alcohol product; and recovering the alcohol product.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention may be better understood through
reference to the following detailed description, taken in
conjunction with the drawings, in which:
[0011] FIG. 1 illustrates a pretreatment and fermentation system,
according to an embodiment of the present invention;
[0012] FIG. 2 illustrates a dewatering system, according to an
embodiment of the present invention;
[0013] FIG. 3 illustrates an acid springing system, according to an
embodiment of the present invention;
[0014] FIG. 4 illustrates a hydrogenation system, according to an
embodiment of the present invention;
[0015] FIG. 5 illustrates a biomass converting system, according to
an embodiment of the present invention; and
[0016] FIG. 6 illustrates a flow diagram of a method for producing
carboxylic acids and alcohols, according to an embodiment of the
invention.
DETAILED DESCRIPTION
[0017] The present invention relates to systems, methods, and
devices for the conversion of biomass, particularly lignocellulosic
biomass, to carboxylic acids and alcohols, particularly primary
alcohols.
[0018] Referring now to FIG. 1, pretreatment and filtration system
10 may be provided in which biomass pile 12 may be blended with
lime or quick lime (calcium carbonate or calcium oxide) and carbon
dioxide (not shown) and piled on top of pit 14 filled with gravel
16. Pit 14 may also be lined with liner 18. Biomass pile 12 may
include any sort of biomass. In selected embodiments it may include
lignocellulosic biomass, such as processed sugarcane or sorghum
stalks or corn stover. Perforated drain pipe 20 may be embedded in
gravel 16. Biomass pile 12 may be covered by cover 22 to keep out
rain and debris, particularly if system 10 is outside. Pump 24 may
circulate water 34 from pit 14 to the top of biomass pile 12. As
water 34 circulates through pile 12, it may flow through heat
exchanger 26, which may regulate the temperature. Cooling water or
heat source 28 may also circulate through heat exchanger 26.
[0019] During approximately the first month after biomass pile 12
is assembled, air 38 may be blown through pile 12 using blower 30.
To remove carbon dioxide from the air, it may be bubbled through
lime water slurry 32. Oxygen-rich air 28 may also be supplied. The
combined effect of lime plus air 28 in pile 12 removes lignin from
the biomass, rendering it more digestible. Further, the lime
removes acetyl groups from hemicellulose, which also helps
digestibility. Once the lime is exhausted, the pH drops to near
neutral, at which point a mixed-culture inoculum may be added.
[0020] The inoculum may be derived from any source, but in many
embodiments it may be derived from soil. Organisms derived from
organic-rich soil in marine environments appear to be particularly
well-suited for use with embodiments of the present invention. Such
organisms are able to be productive in high-salt environments. For
example, the inoculum may include a salt-tolerant
microorganism.
[0021] After inoculation, the organisms digest the biomass and
convert it to carboxylic acids. These acids react with the calcium
carbonate or calcium oxiode in pile 12, producing calcium
carboxylate salts or other calcium salts that are dissolved in the
water that circulates through the pile. This aqueous solution,
called fermentation broth 36 may be harvested and sent for further
processing.
[0022] Referring now to FIG. 2, fermentation broth 36 may be
dewatered in dewatering system 40. Fermentation broth 26 may be
pumped through heat exchanger 42, which preheats the broth.
Preheated fermentation broth 36 may then be acidified with
high-molecular-weight carboxylic acid 46 (e.g. caproic, valeric,
hepotanoic acids). Acidified fermentation broth 36 may be sent to
stripping column 44 where steam 80 strips out dissolved carbon
dioxide, a noncondensible gas that may interferes with evaporator
58 and cause calcium carbonate scaling on heat exchanger 56.
Preferably, stripper 44 may operate at 1 atm, or higher, which
allows exiting steam 86 to be used for heat elsewhere in the
process. Further, if heat exchanger 42 becomes fouled by dissolved
calcium carbonate, the pressure in stripper 44 may be reduced,
which lowers the temperature of steam exiting heat exchanger 42 and
may reduce fouling. However, if stripper 44 is operated at a
reduced pressure, a vacuum pump (not shown) may be needed to remove
the noncondensible gases from fermentation broth 36.
[0023] Steam-stripped, acidified fermentation broth 36 may then be
sent to mixer 48 where the pH may be raised to between
approximately 11 and 12 through the addition of lime 50 from
reservoir 78, which causes scum 54 to precipitate. Scum 54 may then
be removed in solids separator 52. This degassed, descummed
fermentation broth 36 may be further heated in heat exchanger 56,
after which it may enter evaporator 58. Compressor 60 may evaporate
water from the low-pressure chamber of evaporator 58. The heat of
condensation released in the high-pressure chamber of evaporator 58
may provide the heat of evaporation needed in the low-pressure
chamber. The energy needed to drive the evaporation process may be
provided by an engine.
[0024] In the embodiment shown in FIG. 2, a combined cycle engine
may be used, which increases energy efficiency. Gas turbine 88 may
provide shaft power to compressor 60. Gas turbine may use fuel 74.
Exhaust gas 72 from gas turbine 88 may be directed to boiler 62,
which may produce high-pressure steam that may drives steam turbine
64. Heat exchanger 66 may condense the low-pressure steam exiting
steam turbine 64. Cooling water 76 may be used to facilitate this
cooling. Distilled water 82 from the high-pressure section of
evaporator 58 may be cooled in heat exchangers 56 and 42, and may
be returned to pretreatment/fermentation system 10. Concentrated
product 68 may be cooled in heat exchangers 56 and 42, and sent to
acid springing system 90. Liquid turbine 70 may recapture some work
from the high-pressure liquids that exit evaporator 58.
[0025] Pumps 84 may be included at various points in the system to
facilitate fluid flow.
[0026] Referring now to FIG. 3, concentrated product 68 may next be
sent to acid springing system 90. In mixer 92, concentrated product
68 from dewatering system 40 may be mixed with carbon dioxide 94
and low-molecular-weight tertiary amine 96, such as triethyl amine.
The carboxylate reacts with low-molecular-weight tertiary amine 96
to form a soluble salt. The calcium reacts with carbon dioxide 94
to form insoluble calcium carbonate 98, which may be recovered
using solids separator 100. Calcium carbonate 98 may then be washed
with distilled water to remove adhering product and steam stripped
in vessel 102 to ensure that all low-molecular-weight tertiary
amine 96 is removed from calcium carbonate 98. Calcium carbonate 98
may then be sent to pretreatment/fermentation system 10 to act as a
buffer or to a lime kiln (not shown) to be converted to lime.
[0027] Aqueous solution 104 contains dissolved low-molecular-weight
tertiary amine carboxylate. It may then be preheated in heat
exchanger 106 and sent to evaporator 108, where most of the water
may be removed using the same vapor-compression technology used in
dewatering system 40. Specifically, turbine 130 may provide energy
to compressor 132. Waste fluid exiting evaporator 108 may be sent
to column 134 where it may be combined with lime 136 and steam 138
to provide additional product stream to mixer 92 and water 140 to
pretreatment/fermentation system 10.
[0028] The concentrated low-molecular-weight tertiary amine
carboxylate solution 104 may then be sent to column 110 where
high-molecular-weight tertiary amine 112, such as trioctyl amine or
triethanol amine, may be added. Low-molecular-weight tertiary amine
96 may be replaced and exit the top of column 110, while
high-molecular-weight tertiary amine carboxylate solution 104 may
exit the bottom of column 110.
[0029] The high-molecular-weight tertiary amine carboxylate
solution 104 may then be preheated in heat exchanger 114 and sent
to column 116. In column 116, the temperature may be high enough to
break chemical bonds, allowing the more volatile carboxylic acids
146 to exit the top of column 116. The less volatile
high-molecular-weight tertiary amine 112 may exit the bottom of the
column and may be recycled to column 110.
[0030] Any salts 120 that are in high-molecular-weight tertiary
amine 112 may be removed using a solids separator 118. Recovered
salts 120 may be washed with volatile solvent 122, such as triethyl
amine, to remove high-molecular-weight tertiary amine 112 in
separator 118. Solvent 122 may be separated from the recovered
high-molecular-weight tertiary amine in distillation column 124.
Salts 120 may then be steam stripped in stripper 126 to remove
volatile solvent 122 and form solids 144.
[0031] System 90 may contain various heat exchangers 140 that may
be used to recycle process heat. Various fluids may pass through
these heat exchangers, such as cooling waters 142, steam 148, and
fuel 150. In one heat exchanger 140, steam 86 from dewatering
system 40 may be used as a heat source then collected in condenser
152 where carbon dioxide 154 may be separated from water 156, which
may be returned to fermentation/pretreatment system 10.
[0032] Pumps 158 may also be included at various points in the
system to facilitate fluid flow.
[0033] Referring now to FIG. 4, mixed carboxylic acids 146 from
acid springing system 90 may be sent to hydrogenation system 170.
Mixed acids 146 may be placed in column 172 and combined with
high-molecular-weight alcohol 174 such as heptanol. Carboxylic
acids 146 react with alcohol 174 to form ester 176 and water 178.
Water 178 may be separated in column 172 and sent to heat exchanger
180 then returned to column 172 or used elsewhere in systems 10,
40, 90 or 170. Ester 176 may be sent to hydrogenation reactor 182
which contains a suitable hydrogenation catalyst, such as a Raney
nickel. In reactor 182, hydrogen 200 is added and ester 176 is
converted to alcohol. Solids may be separated from alcohol 184
using solids separator 186. Alcohol mixture 184 may be sent column
188 which may recover high-molecular-weight alcohol 174 from the
bottom and alcohol product 190 from the top. Alcohol product 190
may be a primary alcohol.
[0034] System 170 may contain various heat exchangers 192 that may
be used to recycle process heat. Various fluids may pass through
these heat exchangers, such as cooling waters 194 and steam 196.
Pumps 198 may also be included at various points in the system to
facilitate fluid flow.
[0035] Alternative systems to recover carboxylic acids without
production of alcohol are known in the art any may be used in place
of the hydrogenation system of FIG. 4.
[0036] Referring now to FIG. 5, system 300 may include as
subsystems 302 pretreatment/fermentation system 10, dewatering
system 40, acid sprining system 90 and optionally also
hydrogenation system 170. System 300 may reuse process heat, water,
lime, carbon dioxide and other materials among different subsystems
302.
[0037] In an alternative embodiment not explicitly shown, ammonia
may be used in place of low-molecular-weight tertiary amine 96 in
acid sprining system 90. Further, if the ammonia is supplied
earlier, the a reaction between calcium carboxylate, carbon dioxide
and ammonia may occur prior to entry into dewatering system 40. In
this embodiment, an aqueous solution of ammonia carboxylate may be
evaporated in dewatering system 40 rather than calcium carboxylate.
This may help prevent scaling in heat exchangers or system 40
because ammonium salts have a lesser tendency to scale than calcium
salts. Ammonia is also cheap and lost ammonia may be diverted to
pretreatment/fermentation system 10 where it may serve as a
nitrogen source. However, ammonia may react with carboxylic acids
to form amides, which may not be a desired byproduct.
[0038] Embodiments of the invention may include all processes
involved in the operation of the above-described systems. Referring
now to FIG. 6, the invention may include an integrated method for
producing carboxylic acids and alcohols. The method may include
treating pile of biomass 12 with lime or quick lime, water 34, an
inoculum and air in step 400 to produce fermentation broth 36. In
step 410, fermentation broth 36 may be acidified with
high-molecular-weight carboxylic acid 46 then, in step 420,
stripped in stripping column 44. In step 430, the product may be
concentrated in evaporator 58 to produce concentrated product 68.
Concentrated product 68 may be mixed with carbon dioxide 94 and
low-molecular-weight tertiary amine 96 in step 440 to form a
low-molecular-weight tertiary amine carboxylate. This carboxylate
may be exchanged with high-molecular-weight tertiary amine 112 in
column 110 in step 450 to produce a high-molecular-weight tertiary
amine carboxylate. The high-molecular-weight tertiary amine
carboxlate may be heated in column 116 to a temperature high enough
to break the acid to amine bonds in step 460. This produces
carboxylic acids 146 which may be recovered in step 470. In some
embodiments, carboxylic acids 146 may be combined with
high-molecular-weight alcohol 174 to form ester 176 in step 480. In
step 490, ester 176 may be hydrogenated in chamber 182 to form
alcohol product 190. In step 500, high-molecular-weight alcohol 174
and alcohol product 190 may be separated in column 188. Alcohol
product 190 may be a primary alcohol.
[0039] In an alternative embodiment, ammonia may be used in place
of low-molecular-weight tertiary amine 96. Ammonia may be added
immediately after step 400.
[0040] Various methods, systems and apparati useful in the present
invention may also be described in U.S. Pat. No. 6,043,392, issued
Mar. 28, 2000, U.S. Pat. No. 5,986,133, issued Nov. 16, 1999, U.S.
Pat. No. 6,478,965, issued Nov. 12, 2002, U.S. Pat. No. 6,395,926,
issued May 28, 2002, U.S. Pat. No. 5,962,307, issued Oct. 5, 1999,
and WO 04/041995, published May 21, 2004, and their US and foreign
counterpart applications and patents. All of the above patents and
applications are incorporated by reference herein.
* * * * *