U.S. patent application number 13/631182 was filed with the patent office on 2013-08-22 for process for producing a refinery stream-compatible bio-oil from a lignocellulosic feedstock.
This patent application is currently assigned to Chevron USA, Inc.. The applicant listed for this patent is Jason C. Hicks, Jerome F. Mayer, Douglas G. Naae, Horacio Trevino, Jose I. Villegas. Invention is credited to Jason C. Hicks, Jerome F. Mayer, Douglas G. Naae, Horacio Trevino, Jose I. Villegas.
Application Number | 20130212930 13/631182 |
Document ID | / |
Family ID | 47040817 |
Filed Date | 2013-08-22 |
United States Patent
Application |
20130212930 |
Kind Code |
A1 |
Naae; Douglas G. ; et
al. |
August 22, 2013 |
PROCESS FOR PRODUCING A REFINERY STREAM-COMPATIBLE BIO-OIL FROM A
LIGNOCELLULOSIC FEEDSTOCK
Abstract
In one aspect, a method for rendering biomass-derived pyrolysis
oil miscible with refinery hydrocarbons comprises mixing a high
oxygen content bio-oil having an oxygen content of at least about
10 wt. % with a low oxygen content bio-oil having an oxygen content
of less than about 8 wt. % to produce a blended oil. The blended
oil may be hydrotreated to produce a deoxygenated hydrotreated
mixture from which water is removed using a separator, resulting in
a low oxygen content hybrid bio-oil intermediate miscible in
refinery process streams. A portion of the low oxygen content
hybrid bio-oil intermediate may be recycled with the high oxygen
content bio-oil or removed for use in a refinery process stream for
further hydroprocessing.
Inventors: |
Naae; Douglas G.; (Sugar
Land, TX) ; Hicks; Jason C.; (Fort Bend, TX) ;
Mayer; Jerome F.; (Lincoln, CA) ; Trevino;
Horacio; (Richmond, CA) ; Villegas; Jose I.;
(Emeryville, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Naae; Douglas G.
Hicks; Jason C.
Mayer; Jerome F.
Trevino; Horacio
Villegas; Jose I. |
Sugar Land
Fort Bend
Lincoln
Richmond
Emeryville |
TX
TX
CA
CA
CA |
US
US
US
US
US |
|
|
Assignee: |
Chevron USA, Inc.
San Ramon
CA
|
Family ID: |
47040817 |
Appl. No.: |
13/631182 |
Filed: |
September 28, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61542083 |
Sep 30, 2011 |
|
|
|
Current U.S.
Class: |
44/307 ; 422/187;
435/166 |
Current CPC
Class: |
C10G 2300/1011 20130101;
C10G 3/50 20130101; C10G 3/40 20130101; Y02P 20/145 20151101; C10B
53/02 20130101; Y02E 50/10 20130101; Y02E 50/14 20130101; C10G
2300/203 20130101; C10G 2300/202 20130101; Y02P 30/20 20151101;
C10C 5/00 20130101; C10L 1/02 20130101 |
Class at
Publication: |
44/307 ; 435/166;
422/187 |
International
Class: |
C10L 1/02 20060101
C10L001/02 |
Claims
1. A method for rendering biomass-derived pyrolysis oil miscible
with refinery hydrocarbons, the method comprising the steps of: a)
mixing (i) a high oxygen content bio-oil comprising an oxygen
content of at least about 10 wt. % with (ii) a low oxygen content
bio-oil an oxygen content of less than about 8 wt. % to yield a
blended oil.
2. The method of claim 1, further comprising: b) hydrotreating the
blended oil to yield a hydrotreated mixture comprising (i) low
oxygen-content hydrotreated bio-oil and (ii) water, wherein the low
oxygen-content hydrotreated bio-oil has an oxygen content of 10 wt.
% or less.
3. The method of claim 2, further comprising: c) removing water
from the hydrotreated mixture to yield a low oxygen content hybrid
bio-oil intermediate, wherein water removal is effected via a phase
separation between the low oxygen content hydrotreated bio-oil and
the water.
4. The method of claim 3, further comprising: d) combining at least
a portion of the low oxygen content hybrid bio-oil intermediate
with the high oxygen content bio-oil in step (a), and e) repeating
steps (a) through (d).
5. The method of claim 1, wherein the high oxygen content bio-oil
is produced in a conversion reactor by a conversion process
selected from the group consisting of fast pyrolysis, slow
pyrolysis, liquefaction, gasification, or enzymatic conversion.
6. The method of claim 1, wherein the high oxygen content bio-oil
comprises an oxygen content between about 25 wt. % and 50 wt.
%.
7. The method of claim 1, wherein the low oxygen content bio-oil
comprises a biomass feedstock produced by pyrolysis or catalytic
pyrolysis, hydroliquefaction via catalytic hydrogenation, or by
hydrogen donor solvent liquefaction.
8. The method of claim 1, wherein the low oxygen content bio-oil is
produced from a hydrotreated lignocellulosic feedstock.
9. The method of claim 1, wherein the low oxygen content bio-oil
comprises an oxygen content up to about 8 wt. %.
10. The method of claim 1, wherein the low oxygen content bio-oil
has a total acid number less than about 10 mg KOH/g.
11. The method of claim 1, wherein upon mixing in the first mixing
unit, the ratio of the high oxygen content bio-oil to the low
oxygen content bio-oil in the blended oil is between about 0.1 and
about 0.3.
12. The method of claim 1, wherein the high oxygen content bio-oil
and the low oxygen content bio-oil are mixed so that the blended
oil has a total acid number between about 50-100 mg KOH/g.
13. The method of claim 4, wherein the wherein the low oxygen
content hybrid bio-oil intermediate is substantially miscible in a
non-polar solvent.
14. The method of claim 4, wherein the low oxygen content hybrid
bio-oil intermediate has a total acid number less than or equal to
20 mg KOH/g.
15. The method of claim 4, wherein the low oxygen content hybrid
bio-oil intermediate has an average molecular weight between about
200-300 g/mol and a boiling point range below 500.degree. C.
16. The method of claim 4, wherein the wherein the low oxygen
content hybrid bio-oil intermediate is added to a second low oxygen
content bio-oil in a second mixing unit to yield a second blended
oil, wherein the second blended oil is added to the high oxygen
content bio-oil in the first mixing unit.
17. A system for producing a bio-oil comprising: a biomass
conversion unit facilitating production of a high oxygen content
bio-oil from a biomass feedstock; a first mixing unit comprising a
first inlet receiving the high oxygen content bio-oil from the
conversion unit and a second inlet receiving a low oxygen content
bio-oil from a bio-oil feedstock to form a blended oil; a
hydrotreater comprising an inlet receiving the blended oil from the
first mixing unit to produce a hydrotreated bio-oil mixture; a
separator for separating water from the hydrotreated bio-oil
mixture to produce a low oxygen content hybrid bio-oil
intermediate, the separator comprising a first inlet receiving the
hydrotreated bio-oil mixture from the hydrotreater, an outlet
supplying the low oxygen content hybrid bio-oil intermediate to the
first mixing unit, and optionally an outlet supplying the low
oxygen content hybrid bio-oil intermediate to a source of refinery
hydrocarbons.
18. The system of claim 17, further comprising a second mixing
unit, wherein the second mixing unit comprises a first inlet
receiving the low oxygen content hybrid bio-oil intermediate from
the separator, a second inlet receiving a low oxygen content
bio-oil from a bio-oil feedstock to produce a low oxygen blended
oil, and an outlet supplying the low oxygen blended oil formed in
the second mixing unit to the first mixing unit; and wherein the
separator further comprises an outlet supplying the low oxygen
content hybrid bio-oil intermediate to the second mixing unit.
19. The system of claim 17, wherein the biomass conversion unit
comprises a pyrolyis unit for forming a high oxygen content
pyrolyis oil.
20. A blended oil composition, comprising a high oxygen content
bio-oil with an oxygen content of at least about 10 wt. % bio-oil
blended with a low oxygen content bio-oil with an oxygen content of
less than about 8 wt. %.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C.
.sctn.119(e) to U.S. Application Ser. No. 61/542,083, filed Sep.
30, 2011, and which is included by reference in its entirety
herein.
FIELD
[0002] The invention relates generally to compositions and methods
for preparing biofuels, including lignocellulose-derived bio-oils
compatible with refinery process streams.
BACKGROUND
[0003] A bio-oil produced from a lignocellulosic feedstock,
typically has a high oxygen content, in the range of 10-25% O, or
higher. In order for a bio-oil to be processed with a conventional
refinery stream, the bio-oil needs to be miscible, or soluble, with
the refinery stream. Incompatible liquids frequently will have flow
or phase separation problems in flow lines, vessels or
reactors.
[0004] Biomass liquefaction processes, such as wood pyrolysis or
wood liquefaction with a donor solvent, are coarse transformations
with minimal control on the chemical makeup of the product bio-oil.
Specifically, the oxygen content and average molecular weight of
the bio-oil has not been controlled sufficiently to make the oil
compatible (miscible) with the refinery stream for further
hydroprocessing. In addition, these coarse bio-oils may be highly
reactive during catalytic hydrogenation with the result that they
are prone to easy degradation and unwanted side reactions, such as
charring.
[0005] There is a need in the art for systems enabling the use of
lignocellulosic feedstock-derived bio-oils compatible with refinery
process streams. The present disclosure addresses this need and
more and describes: 1) compositions of processed bio-oil compatible
with refinery streams; and, 2) processes and systems for converting
a bio-oil precursor to a bio-oil compatible with refinery process
streams.
SUMMARY OF THE INVENTION
[0006] In one aspect, compatibility of a bio-oil with a refinery
process stream is achieved by using a previously hydrotreated
bio-oil blend as a recycle oil in a process, whereby a coarse
bio-oil is mixed with the recycled bio-oil in a controlled ratio to
form a mixture from which oxygen and water are removed. The
resultant bio-oil product in from this process has reduced oxygen
content, lower molecular weight, and is suitably miscible for use
in a refinery stream for further hydroprocessing, or it can be used
as recycle oil for processing additional coarse bio-oil.
[0007] In one embodiment, a method for rendering biomass-derived
pyrolysis oil miscible with refinery hydrocarbons comprises mixing
a high oxygen content bio-oil having an oxygen content of at least
about 10 wt. % with a low oxygen content bio-oil having an oxygen
content of less than about 8 wt. % to produce a blended oil. The
blended oil has an oxygen content for suitable miscibility.
[0008] In a further step, the blended oil is hydrotreated to yield
a hydrotreated mixture comprising (i) low oxygen-content
hydrotreated bio-oil and (ii) water, wherein the low oxygen-content
hydrotreated bio-oil has an oxygen content of 10 wt. % or less.
[0009] In a further step, water is removed from the hydrotreated
mixture via a phase separation between the low oxygen content
hydrotreated bio-oil and the water to yield a low oxygen content
hybrid bio-oil intermediate. Addition of a solvent may be
unnecessary. The water may readily phase separate from the
hydrotreated bio-oil, with the bio-oil floating on top of the
water, so a typical water separator process may be used. Azeotropic
distillation may be useful for determining the amount of water in a
mixed bio-oil/water sample where good phase separation does not
occur. One aspect of the claimed process is that it produces a
bio-oil which readily phase separates from any associated water
produced or carried into the process. A portion of the low oxygen
content hybrid bio-oil intermediate may be recycled with the high
oxygen content bio-oil according to the above described
embodiments. Alternatively, a portion of the low oxygen content
hybrid bio-oil intermediate may be removed for use in a refinery
stream for further hydroprocessing.
[0010] In another aspect, a system for producing a bio-oil
comprises a mixing unit, a hydrotreater, and a separator. The
system may further comprise biomass conversion unit and a second
mixing unit. The biomass conversion unit facilitates production of
a high oxygen content bio-oil from a biomass feedstock. The mixing
unit comprises a first inlet receiving the high oxygen content
bio-oil from the conversion unit and a second inlet receiving a low
oxygen content bio-oil from a bio-oil feedstock to form a blended
oil. The hydrotreater comprises an inlet receiving the blended oil
from the mixing unit to produce a hydrotreated bio-oil mixture. The
separator separates and removes water from the hydrotreated bio-oil
mixture to produce a low oxygen content hybrid bio-oil intermediate
and includes an inlet receiving the hydrotreated bio-oil mixture
from the hydrotreater, an outlet supplying at least at least a
portion the low oxygen content hybrid bio-oil intermediate to the
mixing unit, and optionally an outlet supplying at least another
portion of the low oxygen content hybrid bio-oil intermediate to a
source of refinery hydrocarbons.
[0011] In some embodiments, the system may further comprise a
second mixing unit comprising a first inlet receiving the low
oxygen content hybrid bio-oil intermediate from the separator, a
second inlet receiving a low oxygen content bio-oil from a bio-oil
feedstock to produce a low oxygen blended oil, and an outlet
supplying the low oxygen blended oil formed in the second mixing
unit to the first mixing unit. The separator further comprises an
outlet supplying the low oxygen content hybrid bio-oil intermediate
to the second mixing unit.
[0012] In another aspect, the present invention provides a blended
oil composition that can be used in the above described system. In
one embodiment, the blended oil composition comprises a high oxygen
content bio-oil with an oxygen content of at least about 10 wt. %
bio-oil blended with a low oxygen content bio-oil with an oxygen
content of less than about 8 wt. %, wherein the ratio of the high
oxygen content bio-oil to the low oxygen content bio-oil in the
blended oil is at least about 5%, 10%, or 20% up to about 30%, 40%,
50%, and up to about 90%. An average molecular weight of the low
oxygen content bio-oil may be about 100 g/mol, 125 g/mol, or 150
g/mol up to about 300 g/mol, 400 g/mol, or 500 g/mol. An average
molecular weight of the high oxygen content bio-oil may be about
150 g/mol, 200 g/mol, or 250 g/mol up to about 800 g/mol, 900
g/mol, or 1000 g/mol.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The accompanying drawings illustrate one or more embodiments
of the invention and, together with the written description, serve
to explain the principles of the invention. Wherever possible, the
same reference numbers are used throughout the drawings to refer to
the same or like elements of an embodiment.
[0014] FIG. 1 depicts, in stepwise fashion, a method for rendering
biomass-derived bio-oil miscible with refinery hydrocarbons in
accordance with some embodiments of the present invention.
[0015] FIG. 2 depicts a system for rendering biomass-derived
bio-oil miscible with refinery hydrocarbons in accordance with some
embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Certain terms and phrases are defined throughout this
description as they are first used, while certain other terms used
in this description are defined below:
[0017] As used herein, the term "biomass" refers to any organic
matter collected for use as a source of energy as further described
herein.
[0018] The term "biofuel" refers to a fuel product at least partly
derived from "biomass," the latter comprising a renewable resource
of organic materials.
[0019] The term "bio-oil" refers to a liquid biofuel product
comprising oxygen-containing organic compounds produced by
thermochemical treatment of a solid biomass feedstock, such as by
pyrolyis, or a natural oil, already present in the feedstock, and
typically produced by mechanical and/or solvent extraction
methods.
[0020] The terms "feed" or "feedstock" refer to a hydrocarbonaceous
material fed into one or more of the systems or processes of the
present invention in order to make a fuel, lubricant, or other
commercial product. A biomass feedstock useful for the methods
described herein can be a solid fuel, bio-oil, fluid fuel (e.g., a
fuel that includes a liquid or a gas).
[0021] The term "pyrolysis" or "pyrolyzing" refer to the thermal
processing and/or thermal decomposition of hydrocarbonaceous
material, typically carried out in a non-oxidative environment.
[0022] The term "pyrolysis oil" refers to a liquid hydrocarbon
product resulting from the pyrolyzing treatment of
hydrocarbonaceous material.
[0023] The terms "hydroprocessing" or "hydrotreating" are used
interchangeably herein with reference to processes or treatments
that react a hydrocarbon-based material with hydrogen, typically
under pressure and with a catalyst (hydroprocessing can be
non-catalytic). Such processes include, but are not limited to,
hydrodeoxygenation (of oxygenated species), hydrotreating,
hydrocracking, hydroisomerization, and hydrodewaxing. For examples
of such processes, see Cash et al., U.S. Pat. No. 6,630,066; and
Elomari, U.S. Pat. No. 6,841,063.
[0024] The present invention provides a processed bio-oil
composition compatible with refinery streams and a process for
converting a bio-oil precursor to a bio-oil compatible with
refinery streams. In one aspect, compatibility of a bio-oil with a
refinery process stream is achieved by using a previously
hydrotreated bio-oil blend as a recycle oil in a process, whereby a
coarse bio-oil is mixed with the recycled bio-oil in a controlled
ratio to form a mixture from which oxygen and water are removed.
The resultant bio-oil product formed from this process has reduced
oxygen content, lower molecular weight, and is suitably miscible
for use in a refinery stream for further hydroprocessing, or it can
be used as recycle oil for processing additional coarse
bio-oil.
[0025] In one embodiment, exemplified in FIG. 1, a method for
rendering biomass-derived pyrolysis oil miscible with refinery
hydrocarbons, comprises: (Step 1) pyrolyzing biomass to form a high
oxygen content (HOC) bio-oil; (Step 2) mixing HOC bio-oil with low
oxygen content (LOC) bio-oil; (Step 3) hydrotreating the blended
LOC/HOC mixture; (Step 4) removing water by phase separation to
form a miscible, LOC hybrid bio-oil intermediate; and (Step 5)
supplying a portion of LOC hybrid bio-oil intermediate to refinery
hydrocarbon stream or recycling a portion of the LOC hybrid bio-oil
intermediate back into Step 2.
[0026] In one embodiment, a method for rendering biomass-derived
pyrolysis oil miscible with refinery hydrocarbons comprises mixing
a high oxygen content bio-oil having an oxygen content of at least
about 10 wt. % with a low oxygen content bio-oil having an oxygen
content of less than about 8 wt. % to produce a blended oil.
[0027] In a further embodiment, the blended oil is hydrotreated to
yield a hydrotreated mixture comprising (i) low oxygen-content
hydrotreated bio-oil and (ii) water, wherein the low oxygen-content
hydrotreated bio-oil has an oxygen content of 10 wt. % or less.
Hydrotreating processes in accordance with one or more embodiments
disclosed herein are expected to reduce oxygen content to less than
about 10%, reduce average molecular weight, and generally to
"stabilize" the bio-oil so aging or phase stability may no longer
be an issue or concern. Oxygen is removed by hydrotreatment via
reaction with hydrogen over a suitable catalyst.
[0028] In a further step, water is removed from the hydrotreated
mixture via a phase separation between the low oxygen content
hydrotreated bio-oil and the water to yield a low oxygen content
hybrid bio-oil intermediate. A portion of the low oxygen content
hybrid bio-oil intermediate may be removed for use in a refinery
stream or it may be combined and recycled with the high oxygen
content bio-oil according to the above described embodiments.
[0029] In one embodiment, the high oxygen content bio-oil is
produced in a biomass conversion unit by a conversion process
comprising fast pyrolysis, slow pyrolysis, liquefaction,
gasification, enzymatic conversion, cellulolysis, Fischer-Tropsch
processing or combinations thereof. In a preferred embodiment, the
high oxygen content bio-oil comprises a liquid hydrocarbon product
resulting from pyrolysis of a lignocellulosic feedstock.
[0030] Bio-oils are a complex mixture of biomass compounds,
including oxygenates, that are obtained from an organic matter
collected for use as a source of energy. Any biomass source may be
used as starting materials for the bio-oils of the present
invention. Non-fossilized biomass includes plant biomass (defined
below), animal biomass (any animal by-product, animal waste, etc.),
and municipal waste biomass (residential and light commercial
refuse with recyclables such as metal and glass removed). Biomass
may also include any type of carbonaceous material from a
fossilized source. Fossilized biomass, therefore, can further
encompass various petroleum products, including, but not limited to
petroleum and coal.
[0031] Plant biomass or lignocellulosic biomass includes virtually
any plant-derived organic matter (woody or non-woody) available for
energy on a sustainable basis. Exemplary plants include grasses,
trees, and other sources of lignocellulosic material, including
those derived from municipal waste, food processing wastes,
forestry wastes and pulp and paper byproducts. "Plant-derived"
necessarily includes both sexually reproductive plant parts
involved in the production of seed (e.g., flower buds, flowers,
fruit and seeds) and vegetative parts (e.g., leaves, roots, leaf
buds and stems). Examples of such plants include, but are not
limited to, corn, soybeans, cotton, wheat, rice, and algae. Plant
biomass can include, but is not limited to, agricultural crop
wastes and residues such as corn stover, wheat straw, rice straw,
and sugar cane bagasse. Plant biomass can further include, but is
not limited to, woody energy crops, wood wastes, and residues such
as trees, softwood forest thinnings, barky wastes, sawdust, paper
and pulp industry waste streams, and wood fiber. Examples of such
trees, include, but are not limited to, hybrid poplar trees (e.g.,
Aspen). Additionally, any type of grasses, such as switch grass,
for example, can be used as a plant biomass source. Typically, the
plant biomass for use in the present invention includes starch,
cellulose, hemicellulose, lignin, and combinations thereof.
[0032] Biomass starting materials may also include waste products
from industry, agriculture, forestry, and households. Examples of
such waste products that can be used as biomass include
fermentation waste, straw, lumber, sewage, garbage, vegetable
processing waste, yard waste, including grass clippings, tree
clippings, leaves, and brush, and food leftovers.
[0033] Plant-derived starting materials typically include at least
5 wt. % water, in some embodiments at least 10% wt. % water, 20 wt.
% water, or more. In some embodiments there may be 5 to 50 wt. %
water, 10 to 40 wt. % water or up to about 35 wt. % water. The
water may be present in a single phase with the oil, or primarily
in a second phase (for an example an emulsion with the aqueous
phase as either the major or minor component), or in mixture of
phases. In some preferred embodiments, a second (primarily) water
phase is formed during a hydrogenation reaction and is removed
during or after the hydrogenation treatment.
[0034] The biomass starting materials may be thermally processed
using any conventional process for preparing bio-oils therefrom,
including fast pyrolysis, slow pyrolysis, liquefaction,
gasification, enzymatic conversion, cellulolysis, Fischer-Tropsch
processing, and combinations thereof. Bio-oils resulting therefrom
represent a complex mixture of compounds, often derived from the
thermal breakdown of solid biomass components, including cellulose,
hemicellulose and lignin present in lignocellulosic biomass.
[0035] In a preferred embodiment, the biomass starting materials
are thermally processed via fast pyrolysis. Fast pyrolysis is a
high temperature process (350 to 800.degree. C.) in which a
biologically based feedstock, such as lignocellulosic biomass, is
rapidly heated in the absence of air and vaporizes into a product
gas stream. Fast pyrolysis of solid biomass causes the major part
of its solid organic material to be instantaneously transformed
into a vapor phase. This vapor phase contains both non-condensable
gases (including methane, hydrogen, carbon monoxide, carbon dioxide
and olefins) and condensable vapors. It is the condensable vapors
that constitute the final liquid bio-oil.
[0036] The feedstocks of the present invention may be processed
using a fast pyrolysis reactor, such as that disclosed in U.S. Pat.
Nos. 5,961,780 and 5,792,340. Other known riser reactors with short
residence times may also be employed, for example, but not limited
to U.S. Pat. Nos. 4,427,539, 4,569,753, 4,818,373, 4,243,514 (which
are incorporated by reference). The reactor is preferably run at a
temperature of from about 450.degree. C. to about 600.degree. C.,
more preferably from about 480.degree. C. to about 550.degree. C.
The contact times between the heat carrier and feedstock is
preferably from about 0.01 to about 20 sec, more preferably from
about 0.1 to about 5 sec., most preferably, from about 0.5 to about
2 sec.
[0037] Preferably, the heat carrier used within the pyrolysis
reactor is catalytically inert or exhibits low catalytic activity.
Such a heat carrier may be a particulate solid, preferably sand,
for example, silica sand. By silica sand it is meant any sand
comprising greater than about 80% silica, preferably greater than
about 95% silica, and more preferably greater than about 99%
silica. It is to be understood that the above composition is an
example of a silica sand that can be used as a heat carrier as
described herein, however, variations within the proportions of
these ingredients within other silica sands may exist and still be
suitable for use as a heat carrier. Other known inert particulate
heat carriers or contact materials, for example kaolin clays,
rutile, low surface area alumina, oxides of magnesium and calcium
are described in U.S. Pat. No. 4,818,373 or U.S. Pat. No.
4,243,514.
[0038] As used herein, the phrase "high oxygen content bio-oil"
(HOC bio-oil) comprises an oxygen content of at least 15 wt %
oxygen. In some embodiments, the high oxygen content bio-oil
comprises at least 20 wt % oxygen, at least 25 wt % oxygen, at
least 30 wt % oxygen, at least 35 wt % oxygen, 40 wt % oxygen,
between 25 wt. % and 50 wt. %, and combinations or ranges
therefrom.
[0039] The low oxygen content bio-oil comprises an oxygen content
of about 8 wt. % or less. In some embodiments, the low oxygen
bio-oil comprises an oxygen content between about 5 wt. % and about
8 wt % or less than 5 wt. %. In other embodiments, the low oxygen
content bio-oil has a total acid number less than about 10 mg
KOH/g.
[0040] The low oxygen content bio-oil may comprise a biomass
feedstock produced by any convenient method, including, but not
limited to, pyrolysis or catalytic pyrolysis, hydroliquefaction via
catalytic hydrogenation or by hydrogen donor solvent liquefaction.
Reduction may be by conventional hydrotreating using hydrogen, or
with synthesis gas (CO/H2), or with aqueous reduction using water
plus CO with suitable catalysts. In some embodiments, the low
oxygen content bio-oil is produced from a hydrotreated
lignocellulosic feedstock.
[0041] In one embodiment, the high oxygen content bio-oil is mixed
with the low oxygen content bio-oil, wherein the ratio of the high
oxygen content bio-oil to the low oxygen content bio-oil in the
blended oil is less than or equal to 0.3. In some embodiments, the
high oxygen content bio-oil and the low oxygen content bio-oil are
mixed so that the low oxygen content bio-oil serves as a solvent
for the high oxygen content bio-oil. In other embodiments, the high
oxygen content bio-oil and the low oxygen content bio-oil are mixed
so that the blended oil has a total acid number between about
50-100 mg KOH/g. In yet other embodiments, a bio-oil is pretreated
by hydrotreating the bio-oil prior to admixture in the blended
oil.
[0042] In the present invention, the oxygenates present in the feed
are removed by hydrotreating. "Hydrotreating" may be defined as a
catalytic process, usually carried out in the presence of free
hydrogen, in which the primary purpose when used to process
conventional petroleum derived feed stocks is the removal of
various contaminants, such as arsenic; heteroatoms, such as sulfur,
oxygen, and nitrogen; and aromatics from the feed stock. In the
present process, the primary purpose is to remove the oxygenates in
the feed.
[0043] The method comprises hydrotreating the blended oil by
passing the oil to a hydrotreating unit where the oil is contacted
with a hydrotreating catalyst under a hydrogen atmosphere. The
hydrotreating unit can also be a hydrocracking unit with a
hydrocracking catalyst for breaking additional oxygenates out of
the lignin compounds or any other unit known to remove oxygenates
from a feed.
[0044] In one embodiment, the blended oil is passed to a
hydrotreater where the blended oil is contacted with a
hydrotreating catalyst under a hydrogen atmosphere. Alternatively,
the hydrotreater can comprise a hydrocracking unit with a
hydrocracking catalyst for breaking additional oxygenates out of
e.g, the lignin compounds in the blended oil composition. When
hydrotreating the blended oil, hydrogen is added separately or
together with the blended oil in a reactor, thereby resulting in
the production of low oxygen-content hydrotreated bio-oil and
water. In a continuous process, hydrogen is added along the length
of a reactor. The hydrogen is preferably added in excess of
stoichiometry to maximize reaction rate by minimizing mass transfer
limitations. Exemplary hydrogen flow rates may range between about
50 to about 5,000 standard cubic feet (SCF) of hydrogen per barrel
(bbl) of oil feed. When milder hydrotreatment conditions are
desired, the hydrogen between about 200 to about 2,000 SCF/bbl of
oil feed, from about 400 to about 1,600 SCF/bbl, from about 600 to
about 1,200 SCF/bbl, or combinations thereof.
[0045] Preferably, hydrogen is reacted with the blended oil
feedstock at a level of at least 50 liter/liter, more preferably at
least 100 liter/liter, and still more preferably at least 200
liter/liter, in some embodiments in the range of 100 to 300
liter/liter, and in some embodiments in the range of 100 to 175
liter/liter. Excess hydrogen may be recycled into a reactor.
[0046] The hydrotreater may comprise a metal-containing catalyst
comprising Co--Mo, Ni--Mo, a transition metal, a noble metal, a
metal oxide therefrom, a metal sulfide therefrom, or a combination
thereof. Metal-containing catalysts useful for the methods
described herein include, for example, a transition metal, a noble
metal, or a combination thereof. The term "metal-containing
catalyst" refers to a catalyst that includes a metal, a
metal-containing compound, or a metal-containing composite.
Exemplary metals include Ni, Co, Pd, Pt, Mo, W, Ru, Cu, Cr, Zn, and
combinations thereof. In some embodiments, the metal-containing
catalyst can optionally include a second metal, a second
metal-containing compound, or a second metal-containing composite.
The term "mixed-metal catalyst" refers to a catalyst that contains
more than one metal, metal-containing compound, or metal-containing
composite. Preferred catalysts include those comprising Ni, Co, Mo,
W or combinations thereof, for example, one or more Group VIII
metals and one or more Group VIB metals, for example comprising Ni
and/or Co and W and/or Mo, preferably comprising a combination of
Ni and Mo, or Co and Mo, or a ternary combination such as Ni, Co,
and Mo or Ni, Mo, and W. Particular catalysts include ICR 181 and
ICR511 (commercially available from Chevron Lummus Global), and
Molyvan A (R.T. Vanderbilt Co., Norwalk, Conn.)
[0047] The hydrotreatment catalyst may be further supported on a
suitable support material. In some embodiments, the support
comprises alumina, especially gamma or eta alumina. Chromia and
rare earth oxides may make take up at least part of the support.
Other useful support oxides include titania, zirconia, hafnia,
thoria, vanadia, urania, oxides of manganese, molybdenum and
tungsten, and combined oxides and supports thereof. The support
material typically has a pore volume over 0.2 cm.sup.3/g and a
surface area of at least 1.0, preferably over 15, especially in the
range 50-200 m.sup.2/g.
[0048] The catalyst can be present as a wall coating, fluidized
bed, fixed bed of particles or pellets, etc. A fixed bed of
catalyst particles has the advantage of ease of design and
operation (clean-up and catalyst replacement). In some embodiments,
fluidized bed reactors may be preferred, especially if the bio-oil
is contaminated with inorganic material. In some embodiments, wall
coated reactors, which have certain advantages for heat and mass
transfer, may be preferred.
[0049] The hydrotreater may include any conventional hydrotreatment
device or hydrotreatment process, including but not limited to
hydrodeoxygenation (of oxygenated species), hydrotreating,
hydrocracking, hydroisomerization, hydrodewaxing, and the like. The
hydrotreater may include down flow reactor, autoclave batch
reactor, fixed bed reactor, moving bed reactor, dynamic bed
reactor, fluid bed reactor, slurry reactor, countercurrent free
fall reactor, concurrent riser reactor, ebullated bed reactor, and
reactors with continuous replacement or replenishment of the
catalyst bed.
[0050] Preferably, the hydrotreatment is carried out relatively
mild hydrotreating conditions. In one embodiment, hydrotreatment of
the blended oil is carried out under a hydrogen atmosphere under a
hydrogen partial pressure of about 15 pounds-force per square inch
gauge (psig) to about 3,000 psig, from about 200 psig to about
2,000 psig, from about 400 psig to about 1,500 psig, from about 200
to about 1,000 psig, or combinations thereof.
[0051] In addition, the hydrotreatment may be carried out in a
range of different temperature conditions. In one embodiment, the
hydrotreatment is carried out at a temperatures between about
100.degree. C. to about 500.degree. C., between about 150.degree.
C. to about 350.degree. C., below 300.degree. C., or combinations
thereof. In another embodiment, the hydrotreatment process employs
a temperature gradient across a catalyst bed. In a specific
embodiment, the temperature gradient comprises temperatures between
about 100.degree. C. to 200.degree. C. at the lower temperature
range up to about 300.degree. C. or less at the upper temperature
range.
[0052] In a further embodiment, water is removed from the
hydrotreated mixture in a separator to form a low oxygen content
hybrid bio-oil intermediate. In one embodiment, a portion of the
low oxygen content hybrid bio-oil intermediate may be recycled with
the high oxygen content bio-oil according to the above described
embodiments. Alternatively, a portion of the low oxygen content
hybrid bio-oil intermediate may be removed for use in a refinery
stream for further hydroprocessing.
[0053] Generally, the separator will remove water by a phase
separation process based on differences in volatility. Exemplary
separators or separation methods include phase separation by
decanting, distillation, or separation using membranes. Exemplary
separator units include a phase separators, extractors, purifiers,
distillation columns and the like.
[0054] In a preferred embodiment, water is separated by azeotropic
distillation. Azeotrope selection is driven by the amount and cost
of the azeotrope-forming liquids, the desired boiling temperature,
and the compatibility of the azeotrope-forming liquid with the
hydrotreated mixture. "Compatibility" as used herein means that the
azeotrope-forming liquid is co-soluble with the hydrotreated
mixture, i.e., there is no phase separation upon mixing of the
hydrotreated mixture and the azeotrope-forming liquid(s). While
certain azeotrope-forming liquids and azeotropes have been
identified, the present invention is not so limited. Other
azeotrope-forming liquids and azeotropes may be used if they form
an azeotrope with water alone or with water in combination with
other azeotrope-forming liquids.
[0055] Azeotropic distillation can be conducted using a Dean Stark
trap or equivalent apparatus and the temperature is set to an
elevated temperature in the range of about 130.degree. C. to about
150.degree. C., such as about 145.degree. C., and it should be
appreciated that distillation may start after a period of time to
allow the reaction mixture to reach about 95.degree. C. to
105.degree. C. Once the distillation commences, the gas flow for
the inert atmosphere (such as a blanket under N.sub.2) can be
increased to about 0.1 SCFH to about 1.0 SCFH, such as 0.5 SCFH as
an example. The temperature is maintained at the selected elevated
temperature for sufficient time, which may be about an additional 2
hours to about 2.5 hours.
[0056] Effective azeotrope-forming liquids for preparing low oxygen
content hybrid bio-oil intermediate compositions include toluene,
ethanol, acetone, 2-propanol, cyclohexane, 2-butanone, octane,
benzene, ethyl acetate, and combinations thereof. Exemplary
suitable azeotropes formed during process include binary azeotropes
such as ethanol/water, toluene/water, acetone/water,
2-propanol/water, cyclohexane/water, 2-butanone/water, and
octane/water and ternary azeotropes such as ethanol/toluene/water,
1-butanol/octane/water, benzene/2-propanol/water,
ethanol/2-butanone/water, and ethanol/ethyl acetate/water
[0057] The low oxygen content hybrid bio-oil intermediate is
preferably formed with a moderately low oxygen content, generally
<10%, and has a total acid number (TAN) of <20 mg KOH/g. In
one embodiment, the low oxygen content hybrid bio-oil intermediate
has a total acid number less than or equal to 20 mg KOH/g. In other
embodiments, the low oxygen content hybrid bio-oil intermediate has
an average molecular weight between about 200-300 g/mol, with the
highest molecular weight components not greater than 500-600 g/mol.
The boiling point range low oxygen content hybrid bio-oil
intermediate is generally no more than 500.degree. C. with a
typical midpoint of about 300.degree. C., and may be as low as
about 180.degree. C., 200.degree. C., or 220.degree. C.
[0058] Preferably, the low oxygen content hybrid bio-oil
intermediate is formed to be substantially miscible in a non-polar
solvent. For example, suitable miscibility, as used herein, may
refer to a low oxygen content hybrid bio-oil intermediate that may
be greater than about 95% soluble when mixed with the non-polar
solvent in a 10:90 ratio of bio-oil to solvent.
[0059] Where a portion of the low oxygen content hybrid bio-oil
intermediate is combined and recycled with the high oxygen content
bio-oil according to the above described embodiments, the low
oxygen content hybrid bio-oil intermediate may be added to a second
low oxygen content bio-oil in a second mixing unit to yield a
second blended oil, wherein the second blended oil is added to the
high oxygen content bio-oil in a first mixing unit.
[0060] In other embodiments, at least a portion of the low oxygen
content hybrid bio-oil intermediate is directly applied for use in
a refinery process stream. A suitable refinery process stream will
have sufficiently high aromatic content, and will be compatible
with the bio-oil and able to completely dissolve or be miscible
with the bio-oil, without causing phase separation of the highest
boiling or the highest oxygen content components.
[0061] In another aspect, the present invention provides a blended
oil composition, comprising a high oxygen content bio-oil with an
oxygen content of at least about 15 wt. % bio-oil blended with a
low oxygen content bio-oil with an oxygen content of less than
about 8 wt. %, wherein the blended oil has an oxygen content for
suitable miscibility. The blended oil composition may be modified
in accordance with the above method teachings.
[0062] In another aspect, a system for producing a bio-oil
comprises a mixing unit, a hydrotreater, and a separator. The
system may further comprise biomass conversion unit and a second
mixing unit. With reference to FIG. 2, in one embodiment of the
present invention, an exemplary system 100 for producing a refinery
stream compatible bio-oil comprises a mixing unit 112, a
hydrotreater 136, and a separator 150.
[0063] In one embodiment, the system 100 further comprises a
biomass conversion unit 104 (depicted as a pyrolysis unit)
producing a high oxygen content (HOC) bio-oil 108 or pyrolysis oil
(Py-Oil) from a biomass feedstock 102. In FIG. 2, the biomass
conversion unit 104 comprises an inlet 106 receiving the biomass
feedstock 102 and an outlet 110 supplying the HOC bio-oil 108 or
Py-Oil to a first mixing unit 112.
[0064] The first mixing unit 112 comprises a first inlet 116
receiving the HOC bio-oil 108 from the conversion unit 104 and a
second inlet 120 receiving a low oxygen content (LOC) bio-oil 124
from a second biomass feedstock 128 to form a blended LOC/HOC
bio-oil 132. The blended LOC/HOC bio-oil 132 exits from an outlet
134 in the first mixing unit 112 and is received in a hydrotreater
136.
[0065] The hydrotreater 136 comprises a first inlet 140 receiving
the blended LOC/HOC oil 132 from the first mixing unit 112 and a
second inlet 142 receiving hydrogen gas 146. The hydrotreater 136
produces a hydrotreated LOC/water mixture 148, which exits from an
outlet 144 and passes on to a separator 150.
[0066] The separator 150 separates water 164 from the hydrotreated
bio-oil mixture 148 to produce a miscible, LOC hybrid bio-oil
intermediate 156 and water 164. The separator 150 comprises an
inlet 152 receiving the hydrotreated bio-oil mixture 148 from the
hydrotreater 136 and may additionally include an outlet 158
supplying at least a portion of the LOC hybrid bio-oil intermediate
156 to the first mixing unit 112, an outlet 160 supplying at least
a portion of the LOC hybrid bio-oil intermediate 156 to a source of
refinery hydrocarbons 162, an outlet 166 supplying at least a
portion of the LOC hybrid bio-oil intermediate 156 to a second
mixing unit 170, and an outlet 168 for water 164 to exit.
[0067] In some embodiments the system 100 comprises a second mixing
unit 170 comprising an inlet 172 receiving the LOC hybrid bio-oil
intermediate 156 from the separator 150 and an inlet 174 receiving
a LOC bio-oil 124 from a bio-oil feedstock 128 to form a blended
LOC oil 176 exiting from an outlet 178, which supplies the blended
LOC oil 176 formed in the second mixing unit 170 to the first
mixing unit 112. The first mixing unit 112 may further include an
inlet 180 receiving the LOC hybrid oil intermediate 156 from the
separator 150 and an inlet 182 receiving the blended LOC oil 176
from the second mixing unit 170.
[0068] Each reactor vessel of the invention preferably includes an
inlet and an outlet adapted to remove the product stream from the
vessel or reactor. The vessels and reactors may include additional
outlets to allow for the removal of portions of the reactant stream
to help maximize the desired product formation, and allow for
collection and recycling of byproducts for use in other portions of
the system. Further, the apparatuses for conducting the inventive
processes can be conducted batchwise or continuously.
[0069] In another aspect, the present invention provides a blended
oil composition that can be used in the above described system. The
blended oil composition may comprise any of the above described
LOC/HOC bio-oil compositions. In one embodiment, the blended oil
composition comprises a high oxygen content bio-oil with an oxygen
content of at least about 15 wt. % bio-oil blended with a low
oxygen content bio-oil with an oxygen content of less than about 8
wt. %.
[0070] The present invention is further illustrated by the
following examples which should not be construed as limiting. The
contents of all references, patents and published patent
applications cited throughout this application, as well as the
Figures and Tables are incorporated herein by reference to the
extent that they are not inconsistent.
Example 1
Pyrolysis Oil
[0071] A pyrolysis oil was produced from pine sawdust by a fast
pyrolysis method. Chemical analysis of the pyrolysis oil showed 21%
water content, and elemental analyses of 48.72% carbon, 5.97%
hydrogen, <0.05% nitrogen, and 44.64% oxygen (by difference) on
a moisture and ash free basis (MAF). The total acid number (TAN) of
the Pyrolysis Oil was 331 mg KOH/g.
[0072] This resulting Py-Oil was immiscible with n-dodecane. The
low solubility of the Py-Oil in an aromatic solvent was
demonstrated using toluene as a solvent. The Py-Oil was mixed with
five-to-ten times the volume of toluene. The mixture was heated to
boiling and the water removed by azeotropic distillation (Dean
Stark method). The resulting Py-Oil/toluene mixture was allowed to
cool and two phases resulted: a thin, light colored toluene rich
phase and a thick, viscous Py-Oil phase immiscible in toluene. The
toluene-insoluble Py-Oil accounted for 38% of the original
Py-Oil.
[0073] The elemental composition of the toluene-insoluble Py-Oil
phase was 59.3% C, 6.56% H, 0.1% N, and 34.5% 0 (by difference). As
determined by vapor pressure osmometry, the number average
molecular weight (Mn) was 730 g/mol. The high oxygen content and
molecular weight of the toluene-insoluble Py-Oil is consistent with
its low solubility in an aromatic solvent, such as toluene.
Example 2
Lignin Bio-Oil
[0074] A lignin bio-oil was produced by hydrotreating a purified
pine Kraft lignin with hydrogen at 2000 psig and 420.degree. C. and
a suspended iron based catalyst. The chemical analysis of the
resultant lignin oil showed <0.34% water content, and an
elemental analyses of 83.47% carbon, 9.23% hydrogen, 1.19%
nitrogen, 0.40% sulfur, and 5.71% oxygen (by difference). The TAN
of lignin bio-oil was 7 mg KOH/g. The number average molecular
weight of the lignin bio-oil was 229 g/mol.
[0075] The solubility of the lignin bio-oil in toluene was
determined. The bio-oil was mixed with nine times the volume of
toluene. The mixture was heated to reflux, and then allowed to cool
to room temperature. A single organic phase resulted, with the
lignin bio-oil being miscible with the toluene. The lignin bio-oil
was miscible with the toluene due to its low oxygen content,
molecular weight, and TAN value, as compared to the
toluene-insoluble Py-Oil in Example 1.
Example 3
Mild Hydrotreating of Py-Oil+Lignin Oil
[0076] A Py-Oil, as described in Example 1, was blended in line
with a lignin bio-oil, described in Example 2, to yield a 1:3
mixture and directly fed into a hydrotreating, down flow reactor
containing a sulfided NiO/MoO.sub.3 supported catalyst (ICR181).
The process pressure was 800 psig of hydrogen. A temperature
gradient was applied across the catalyst bed, with the inlet
temperature at 140.degree. C., and an outlet temperature of
245.degree. C. The product bio-oil was homogeneous and the water
phase could be separated. Chemical analysis of the bio-oil product
was 80.93% carbon, 9.90% hydrogen, 1.11% nitrogen, and 8.07% oxygen
(by difference). The TAN of the product bio-oil was 17 mg KOH/g.
Simple dilution of the Py-Oil by the lignin oil produced a TAN
value of 88 mg KOH/g.
[0077] The product bio-oil was mixed with about ten times the
volume of toluene. The mixture was heated to boiling and residual
water entrained in the oil was removed by azeotropic distillation
(Dean Stark method). The resulting bio-oil/toluene mixture was then
allowed to cool. A single organic phase resulted, with the product
bio-oil being completely miscible with the toluene.
Example 4
Effect of Catalyst and Py-Oil Ratio on the Hydrotreated Py-Oil
Product
[0078] Similar to Example 3, but the percent of Py-Oil to lignin
bio-oil was varied at 25%, 37.5%, and 50% Py-Oil for three separate
runs. A different sulfided NiO/MoO.sub.3 supported catalyst
(ICR511) was used for these runs. A similar temperature gradient
for the catalyst bed was used as in Example 3, with the outlet
temperature being about 265.degree. C.
[0079] The product bio-oil from each condition was separated from
the water phase. As shown in Table 1 below, determination of the
percent toluene solubility showed that these products exhibited
increasing toluene insolubility, consistent with higher molecular
weight components.
TABLE-US-00001 TABLE 1 Py-Oil/Lignin % Oil Ratio toluene-insoluble
% C % H % N % O (by diff.) 25:75 1.4% 79.15 9.7 1.02 9.76 37.5:62.5
7.0% -- -- -- -- 50:50 10.3% -- -- -- --
[0080] As in Example 3, the hydrotreated product bio-oil from the
25:75 ratio appeared to be homogeneous. The Total Acid Number (TAN)
of this product bio-oil was 15 mg KOH/g.
[0081] The hydrotreated product bio-oils from the 37.5% and 50%
ratio mixtures were non-uniform and each had two distinct organic
phases. This is reflected in their higher toluene insoluble
values.
Example 5
Effect of Hydrotreating Temperature
[0082] Similar to Example 3, but for these runs the reaction
temperature was increased in the lower third of the catalyst bed to
produce six separate run conditions with increasing reaction
temperatures. Table 2 shows the effect of hydrotreating
temperatures on product oil density, % O content, number average
molecular weight, and toluene solubility.
TABLE-US-00002 TABLE 2 Reactor Outlet Temp .degree. C. density % O
(by diff.) Mol Wt % toluene-insoluble 250 1.0291 9.28% 225 0.00%
260 1.0318 10.01% 0.02% 270 1.0216 8.38% 234 0.24% 280 1.0101 7.76%
0.15% 300 0.9967 6.04% 241 0.00% 320 0.9794 4.92% 231 0.00%
Example 6
Lignin Liquefaction in Tetralin Using a Catalyst
[0083] Approximately 2.97 g of Kraft lignin was slurried with
0.0029 g of MolyVan A and 29 mL of tetralin in a 300 mL Autoclave
batch reactor. The reactor was purged and filled with H.sub.2 to
800 psig. After 60 minutes at 400.degree. C., the external heat was
removed and the reactor was allowed to cool. The resulting product
solution was removed from the reactor, collected, and filtered. The
tetralin soluble phase was 21.6 g. The resulting solid was washed
with acetone, and the acetone washings were combined and stripped
to yield a polar phase (tetralin insoluble product, 2.27 g). The
third phase was the residual solid (0.321 g) after the tetralin
filtration and acetone washing steps. The analyses of the products
are shown in Table 3 below.
TABLE-US-00003 TABLE 3 % O Relative (by dif- Amounts % C % H % N %
S ference) Tetralin Soluble 21.6 (89.3%) 89.07 9.41 0.0 0.10 1.52
Phase Tetralin Insoluble 2.27 (9.4%) 89.82 9.75 0.0 -- 0.43 Product
Residual Solids 0.321 (1.3%) 61.00 3.11 0.3 0 20.1
[0084] Based on kraft lignin, the yield of Tetralin insoluble
product was 76%.
Example 7
Lignin Liquefaction in Lignin Bio-Oil Using a Catalyst
[0085] Approximately 10.02 g of Kraft lignin was slurried with
0.1071 g of MolyVan A and 51.65 g of lignin bio-oil (from Example
2) in a 300 mL Autoclave batch reactor. The reactor was purged and
filled with H.sub.2 to 800 psig. After 60 minutes at 400.degree.
C., the external heat was removed and the reactor was allowed to
cool. The resulting material was removed from the reactor and
collected as described by the following. The lignin bio-oil soluble
phase was collected by filtering the entire solution
(.apprxeq.39.47 g). The resulting solid was washed with acetone and
stripped to collect the polar phase (6.53 g). The third phase was
the residual solid after the lignin bio-oil filtration and acetone
washing steps (1.518 g). The analyses of the products are shown in
Table 4 below.
TABLE-US-00004 TABLE 4 % O Relative (by dif- Amounts % C % H % N %
S ference) Lignin Bio-Oil 39.47 (83.1%) 84.60 8.79 0.15 0.105 6.35
Soluble Phase Lignin Bio-Oil 6.53 (13.7%) 82.52 9.08 0 na 7.33
Insoluble Product Residual Solids 1.52 (3.2%)
[0086] Based on kraft lignin, the yield of lignin bio-oil insoluble
product was 65%.
[0087] In both Examples 6 and 7, the solvent insoluble products are
similar, as neither is soluble in the reaction solvent. The data
indicates tetralin is a slightly poorer solvent than the lignin
oil, because the amount of Tetralin insoluble product was higher
than the amount of lignin bio-oil insoluble product.
[0088] The above description is for the purpose of teaching the
person of ordinary skill in the art how to practice the present
invention, and it is not intended to detail all those obvious
modifications and variations of it which will become apparent to
the skilled worker upon reading the description. It is intended,
however, that all such obvious modifications and variations be
included within the scope of the present invention, which is
defined by the following claims. The claims are intended to cover
the claimed components and steps in any sequence which is effective
to meet the objectives there intended, unless the context
specifically indicates the contrary.
* * * * *