U.S. patent application number 17/494167 was filed with the patent office on 2022-01-27 for isolation method for water insoluble lignin components of a biomass.
This patent application is currently assigned to Green Extraction Technologies. The applicant listed for this patent is Green Extraction Technologies. Invention is credited to Melvin Mitchell.
Application Number | 20220025130 17/494167 |
Document ID | / |
Family ID | |
Filed Date | 2022-01-27 |
United States Patent
Application |
20220025130 |
Kind Code |
A1 |
Mitchell; Melvin |
January 27, 2022 |
ISOLATION METHOD FOR WATER INSOLUBLE LIGNIN COMPONENTS OF A
BIOMASS
Abstract
The process includes pretreating the biomass with a first basic
solution such as sodium hydroxide and mechanically altering the
fibers to provide a fluidized biomass. The fluidized biomass is
then subjected to high frequency pulses and shear forces without
denaturing the individual components of the biomass. The biomass is
then subjected to compressive force to separate a first liquid
fraction from a first fractionated biomass. The first fractionated
biomass may again then be subjected to the same high frequency
pulses and shear forces as previously, particularly if there are
hemicellulose and/or sugars still present in the first fractionated
biomass. Compressive forces are used to separate a second liquid
fraction from a second fractionated biomass. The second fractioned
biomass is then subjected to compressive forces to provide lignin
in water soluble form.
Inventors: |
Mitchell; Melvin; (Penrose,
NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Green Extraction Technologies |
Greer |
SC |
US |
|
|
Assignee: |
Green Extraction
Technologies
|
Appl. No.: |
17/494167 |
Filed: |
October 5, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16863135 |
Apr 30, 2020 |
11174355 |
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17494167 |
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15416570 |
Jan 26, 2017 |
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16863135 |
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14454972 |
Aug 8, 2014 |
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15416570 |
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61864853 |
Aug 12, 2013 |
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61909418 |
Nov 27, 2013 |
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61919194 |
Dec 20, 2013 |
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International
Class: |
C08H 7/00 20060101
C08H007/00; C08B 15/08 20060101 C08B015/08; C08B 37/00 20060101
C08B037/00; C08H 8/00 20060101 C08H008/00; D21C 3/02 20060101
D21C003/02; D21C 3/22 20060101 D21C003/22; H01R 13/627 20060101
H01R013/627; H01R 13/6594 20060101 H01R013/6594; H01R 24/60
20060101 H01R024/60; H05K 5/00 20060101 H05K005/00; D21C 1/02
20060101 D21C001/02; D21H 11/00 20060101 D21H011/00; C08G 63/06
20060101 C08G063/06; C08G 63/91 20060101 C08G063/91 |
Claims
1. A process for treating a biomass to produce water insoluble
lignin components of the biomass in water soluble form: a)
pretreating the biomass with a first basic solution; b) subjecting
the pretreated biomass to shear forces and pulses having a
frequency sufficient to fractionate or extract components from the
biomass without denaturing the water insoluble components of the
biomass, wherein the pulses are between about 300 pulses per second
and about 2000 pulses per second and delivered over a duration
between about 1 second and about 3 seconds; c) subjecting the
biomass to compressive force to separate a first liquid fraction
from a first fractionated biomass; d) subjecting the first
fractionated biomass to the same pulses and shear forces of step
b); e) subjecting the first fractionated biomass to compressive
forces to separate a second liquid fraction from a second
fractionated biomass wherein the second fractionated biomass is
substantially devoid of hemicelluloses and sugars; f) subjecting
the second fractionated biomass substantially devoid of
hemicelluloses and sugars to oxidation at a pH above 7; and g)
subjecting the second fractionated biomass to compressive force to
provide lignin in water soluble form.
2. The process of claim 1, further comprising after step e)
contacting the second fractionated biomass substantially devoid of
hemicelluloses and sugars with a second basic solution and
subjecting the second fractionated biomass to compressive force to
separate the lignin from the second fractionated biomass
substantially devoid of hemicelluloses and sugars.
3. The process of claim 2, wherein the first and second basic
solutions comprise sodium hydroxide.
4. The process of claim 1 wherein the steps are conducted at
ambient temperature to about 60.degree. C.
5. The process of claim 1, wherein the lignin in water soluble form
is purified by contacting with a membrane.
6. The process of claim 1, wherein the lignin in water soluble form
is further processed by emulsifying.
7. The process of claim 1, wherein the lignin in water soluble form
is further processed by depolymerizing the lignin.
8. Water soluble lignin produced by the process of claim 1.
9. Emulsified water soluble lignin produced by the process of claim
6.
10. Depolymerized water soluble lignin produced by the process of
claim 7.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S.
application Ser. No. 16/863,135 filed on Apr. 30, 2020, which is a
continuation application of U.S. application Ser. No. 15/416,750,
filed Jan. 26, 2017, which is a continuation application of U.S.
application Ser. No. 14/454,972, filed Aug. 8, 2014, which claims
priority to U.S. Provisional Patent Application Ser. No.
61/864,853, filed Aug. 12, 2013; U.S. Provisional Patent
Application Ser. No. 61/909,418, filed Nov. 27, 2013; and U.S.
Provisional Patent Application Ser. No. 61/919,194, filed Dec. 20,
2013, the disclosures of which are all incorporated herein by
reference in their entireties.
FIELD OF THE INVENTION
[0002] The present invention relates to a process for isolating
components of a biomass. Examples of fractions and extractives
provided in the process include the extraction, isolation, and
purification of lignin, cellulose, sugars, hemicellulose, fibers
and/or extractives.
BACKGROUND OF THE INVENTION
[0003] Natural cellulosic feedstocks are typically referred to as
"biomass." Many types of biomass, including wood, paper,
agricultural residues, herbaceous crops, and lignocellulosic
municipal and industrial solid wastes have been considered as
feedstocks for the production and preparation of a wide range of
goods. Plant biomass materials are comprised primarily of
cellulose, hemicellulose and lignin, bound together in a complex
and entangled gel-like structure along with amounts of
extractables, pectins, proteins and/or ash. Thus, successful
commercial use of biomass as a chemical feedstock depends on the
efficient and/or economical separation and isolation of these
various constituents.
[0004] Many steps are often required in production, harvesting,
storage, transporting, and processing of biomass to yield useful
products. One step in the processing is the separation, or
fractionation, of the biomass into its major components:
extractives, hemicellulose, lignin, and cellulose. Many approaches
have been investigated for disentangling the complex structure of
the biomass. Once this separation has been achieved, a variety of
paths are opened for further processing of each component into
marketable products. For example, the possibility of producing
products such as biofuels, polymers and latex replacements from
biomass has recently received much attention. This attention is due
to the availability of large amounts of cellulosic feedstock, the
need to minimize burning or landfilling of waste cellulosic
materials, and the usefulness of sugar and cellulose as raw
materials substituting for oil-based products.
[0005] One component of the biomass that the isolation of which has
been of interest is lignin. Lignin is a cross-linked racemic
macromolecule with molecular masses in excess of 10,000 Da. It is
relatively hydrophobic and aromatic in nature. The degree of
polymerization in nature is difficult to measure, since it is often
fragmented during typical extraction and the molecule consists of
various types of substructures that appear to repeat in a haphazard
manner. Different types of lignin have been described depending on
the means of isolation.
[0006] There are three monolignol monomers, methoxylated to various
degrees: p-coumaryl alcohol, coniferyl alcohol, and sinapoyl
alcohol. These lignols are incorporated into lignin in the form of
the phenylpropanoids p-hydroxyphenyl (H), guaiacyl (G), and
syringyl (S), respectively. Gymnosperms have a lignin that consists
almost entirely of G with small quantities of H. That of
dicotyledonous angiosperms is more often than not a mixture of G
and S (with very little H), and monocotyledonous lignin is a
mixture of all three. Many grasses have mostly G, while some palms
have mainly S. All lignins contain small amounts of incomplete or
modified monolignols, and other monomers are prominent in non-woody
plants.
[0007] Likewise, cellulose, another component of the biomass has
also been of particular interest, particularly with respect to the
paper industry and in the production of biofuels. Cellulose is an
organic compound with the formula (C.sub.6H.sub.10O.sub.5).sub.n, a
polysaccharide consisting of a linear chain of several hundred to
over ten thousand .beta.(1.fwdarw.4) linked D-glucose units.
Cellulose is an important structural component of the primary cell
wall of green plants, many forms of algae and the oomycetes.
Cellulose is an extremely abundant organic polymer on Earth. The
cellulose content of cotton fiber is 90%, that of wood is 40-50%
and that of dried hemp is approximately 45%. Cellulose is mainly
used to produce paperboard and paper. Smaller quantities are
converted into a wide variety of derivative products such as
cellophane and rayon.
[0008] Thus, there continues to be a need for improved systems and
methods for separating solid biomass into its individual
constituent components, particularly lignin, hemicelluloses, and
cellulose that take into consideration factors such as
environmental and energy concerns, efficiency and
cost-effectiveness.
SUMMARY OF THE INVENTION
[0009] It should be appreciated that this Summary is provided to
introduce a selection of concepts in a simplified form, the
concepts being further described below in the Detailed Description.
This Summary is not intended to identify key features or essential
features of this disclosure, nor is it intended to limit the scope
of the invention.
[0010] The present invention provides a process for isolating
various components of biomass that may be adapted to large-scale
production, uses environmentally friendly solvents and/or is energy
efficient. Moreover, the present invention provides a process for
isolating various water insoluble components of the biomass in
water soluble form while providing a biomass substantially devoid
of hemicellulose, other sugars, and the water insoluble
components.
[0011] The process includes pretreating the biomass with a first
basic solution such as sodium hydroxide. Pretreatment may include
mechanically altering the fibers to, for example, open up the
fibers and to form a fluidized biomass. The biomass with opened up
fibers is then subjected to high frequency pulses and shear forces
without denaturing the individual components of the biomass. The
biomass is then subjected to compressive force to separate a first
liquid fraction from a first fractionated biomass. The first
fractionated biomass may again then be subjected to the same high
frequency pulses and shear forces as previously, particularly if
there are hemicellulose and/or sugars still present in the first
fractionated biomass. Compressive forces are used to separate a
second liquid fraction from a second fractionated biomass. The
second fractionated biomass is high in cellulose and water
insoluble components including lignins and proteins, and is
substantially devoid of hemicelluloses and sugars. The second
fractionated biomass is subjected to oxidation such as with
hydrogen peroxide at a pH of 8 to 12. The second fractioned biomass
is then subjected to compressive forces to separate one or more
water insoluble components of the biomass in water soluble and
liquid form from a second fractionated biomass substantially devoid
of hemicellulose, sugar and the water insoluble components of the
biomass.
[0012] The present invention also provides a water insoluble
component of a biomass in water soluble form at a pH of 5 to 12 at
ambient temperature. Exemplary components which are typically water
soluble include hemicellulose, sugars, pectins, some proteins and
extractives. Components which are typically water insoluble include
lipids, lignins, some proteins and extractives.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 depicts a flow chart that outlines an embodiment of
the process of the invention.
[0014] FIG. 2 depicts a flow chart that outlines another embodiment
of the process of the invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0015] In the following detailed description, embodiments of the
present invention are described in detail to enable practice of the
invention. Although the invention is described with reference to
these specific embodiments, it should be appreciated that the
invention can be embodied in different forms and should not be
construed as limited to the embodiments set forth herein. Rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art.
[0016] The terminology used in the description of the invention
herein is for the purpose of describing particular embodiments only
and is not intended to be limiting of the invention. As used in the
description of the invention and the appended claims, the singular
forms "a," "an" and "the" are intended to include the plural forms
as well, unless the context clearly indicates otherwise. The
invention includes numerous alternatives, modifications, and
equivalents as will become apparent from consideration of the
following detailed description.
[0017] It will be understood that although the terms "first,"
"second," "third," "a)," "b)," and "c)," etc. may be used herein to
describe various elements of the invention should not be limited by
these terms. These terms are only used to distinguish one element
of the invention from another. Thus, a first element discussed
below could be termed a element aspect, and similarly, a third
without departing from the teachings of the present invention.
Thus, the terms "first," "second," "third," "a)," "b)," and "c),"
etc. are not intended to necessarily convey a sequence or other
hierarchy to the associated elements but are used for
identification purposes only. The sequence of operations (or steps)
is not limited to the order presented in the claims or figures
unless specifically indicated otherwise. Steps may be conducted
simultaneously.
[0018] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the present application and relevant art
and should not be interpreted in an idealized or overly formal
sense unless expressly so defined herein. The terminology used in
the description of the invention herein is for the purpose of
describing particular embodiments only and is not intended to be
limiting of the invention. All publications, patent applications,
patents and other references mentioned herein are incorporated by
reference in their entirety. In case of a conflict in terminology,
the present specification is controlling.
[0019] Also as used herein, "and/or" refers to and encompasses any
and all possible combinations of one or more of the associated
listed items, as well as the lack of combinations when interpreted
in the alternative ("or").
[0020] Unless the context indicates otherwise, it is specifically
intended that the various features of the invention described
herein can be used in any combination. Moreover, the present
invention also contemplates that in some embodiments of the
invention, any feature or combination of features set forth herein
can be excluded or omitted. To illustrate, if the specification
states that a complex comprises components A, B and C, it is
specifically intended that any of A, B or C, or a combination
thereof, can be omitted and disclaimed.
[0021] As used herein, the transitional phrase "consisting
essentially of" (and grammatical variants) is to be interpreted as
encompassing the recited materials or steps "and those that do not
materially affect the basic and novel characteristic(s)" of the
claimed invention. See, In re Herz, 537 F.2d 549, 551-52, 190
U.S.P.Q. 461, 463 (CCPA 1976) (emphasis in the original); see also
MPEP .sctn. 2111.03. Thus, the term "consisting essentially of" as
used herein should not be interpreted as equivalent to
"comprising."
[0022] The term "about," as used herein when referring to a
measurable value, such as, for example, an amount or concentration
and the like, is meant to encompass variations of .+-.20%, .+-.10%,
.+-.5%, .+-.1%, .+-.0.5%, or even .+-.0.1% of the specified amount.
A range provided herein for a measureable value may include any
other range and/or individual value therein.
[0023] The term "biomass" includes any non-fossilized, i.e.,
renewable, organic matter. The various types of biomass may include
plant biomass, 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).
[0024] The term "plant biomass" or "ligno-cellulosic biomass"
includes virtually any plant-derived organic matter (woody or
non-woody) available for energy on a sustainable basis.
"Plant-derived" necessarily includes both sexually reproductive
plant parts involved in the production of seed (e.g., flower buds,
flowers, fruit, nuts, and seeds) and vegetative parts (e.g.,
leaves, roots, leaf buds and stems). Plant biomass can include, but
is not limited to, agricultural crop wastes and residues such as
corn stover, wheat straw, rice straw, sugar cane bagasse and the
like. Plant biomass further includes, 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, wood fiber, herbal plant material brewing wastes,
and the like. Additionally grass crops, such as switchgrass and the
like have the potential to be produced in large-scale amounts and
to provide a significant source of another plant biomass. For urban
areas, potential plant biomass feedstock comprises yard waste
(e.g., grass clippings, leaves, tree clippings, brush, etc.) and
vegetable processing waste.
[0025] The biomass comprises three basic chemical
components/fractions, namely hemicellulose, cellulose, and lignins.
The biomass may also include lesser amounts of proteins,
extractives, pectins, and ash depending on the biomass.
Specifically, hemicellulose is a polymer (matrix polysaccharide)
comprising the pentose and hexose sugars xylon, glucuronoxylon,
arabinoxylon, glucomannan, and xyloglucan. The sugars are highly
substituted with acetic acid, and because of its branched
structure, hemicellulose is amorphous. Hemicellulose is also easy
to cleave via hydrolysis. In contract, cellulose is a linear
polymer (polysaccharide) of glucose sugars bonded together by
.beta.-glycosidic linkages to form lengthy linear chains. Hydrogen
bonding can occur between cellulose chains results in a rigid
crystalline structure which is resistant to cleavage. Lignin is a
polymer of phenolic molecules and is hydrophobic. It provides
structural integrity to plants, i.e., it is the glue that maintains
the plant intact.
[0026] Typical ranges of hemicellulose, cellulose, and lignin in,
for example, a plant biomass such as corn stover are:
TABLE-US-00001 Component Biomass Dry Weight Cellulose 30-50%
Hemicellulose 20-40% Lignin 10-25%
[0027] "Ambient temperature" includes the temperature of the
surroundings in which the process of the invention takes place.
Ambient temperature may include, but is not limited to, "room
temperature," and any temperature within the range of 10 to
40.degree. C. (50 to 104.degree. F.).
[0028] Individual components of the biomass may include, but are
not limited to, lignin, cellulose, hemicellulose, proteins,
pharmaceuticals, nutraceuticals and other materials obtained from
the leaves, stems, flowers, buds, roots, tubers, seeds, nuts, fruit
and the like of a plant.
[0029] "Alcohol" includes, but is not limited to, methanol,
ethanol, isopropanol, propanol, isobutanol, butanol, and glycol. A
"short chain alcohol" generally includes C.sub.1 to C.sub.4
alcohols.
[0030] "Water" includes, but is not limited to, deionized water,
spring water, distilled water, mineral water, tap water and well
water, and mixtures thereof "Water soluble" includes a component
that can be dissolved in water or other solvent at ambient
temperature. "Water insoluble" includes a component that cannot be
dissolved in water or other solvent at ambient temperature.
[0031] Referring now to FIG. 1, operations for the fractionation
and extraction of various biomasses, according to some embodiments
of the present invention, will be described. A pretreatment step 90
may be conducted optionally at ambient temperature. The biomass may
be subjected to a pre-soak step 100 and/or disassembly step 110.
The pre-soak step 100 may include contacting with a solvent with or
without additives to facilitate the separation of the individual
components. The disassembly step 110 may include mechanical
disassembling of the biomass to provide the biomass in a fluidized
or flowable state or condition. After the pretreatment step 90, the
biomass may be subjected to high frequency pulses and high shear
forces to fractionate 120 or extract via, for example, the biomass
fractionation apparatus and methods described in co-pending U.S.
patent application Ser. No. 14/454,833, filed on Aug. 8, 2014
(Attorney Docket No. 1237-3) and co-pending U.S. patent application
Ser. No. 14/454,952, filed on Aug. 8, 2014 (Attorney Docket No.
1237-2), the disclosures of which are incorporated by reference in
their entireties. Such fractionation does not denature the one or
more individual components of the biomass. Such fractionation
provides a fraction or extracted product that can be separated from
the fractionated or extracted biomass. Stated otherwise, the
pulsation and shear forces avoid altering the chemical
characteristics of the individual components and does not
substantially result in the fragmentation of such components. The
fractionated or extracted biomass may be subjected to separation,
namely filtration or screening 125 with or without agitation,
followed by a compression force 130, and then followed by
additional filtration and/or separation with or without agitation
140. The fractions may be used to provide a desired product stream
150. In one embodiment, the amount of hemicellulose and sugars in
the fractionated biomass are monitored such as using a brix meter.
If significant hemicellulose or sugars still are present the steps
of subjecting to high frequency pulses and shear forces and
subjecting to compressive forces are repeated.
[0032] As briefly discussed above, in an initial pretreatment step
90 the biomass may be pre-soaked and contacted with a solvent such
as with an alcohol, an aqueous alcohol, water or glycerin or
co-solvent or mixture thereof in order to begin the fractionation
or extraction of the biomass. The biomass may swell during this
pretreatment step 90. The biomass may then be disassembled 110 such
as by chopping, cutting, fraying, attrition or crushing prior to
contact with the solvent 100. In a particular embodiment, if the
biomass is, for example, fresh plant biomass or herbal plant
material, the material may be contacted with alcohol. If the
biomass is dried plant biomass or herbal plan material, it may be
contacted with an aqueous alcoholic solution. This aqueous
alcoholic extraction may be performed in aqueous alcohol at
different concentrations. Suitable alcohols may be short chain
alcohol, such as, but not limited to, methanol, ethanol, propanol,
isopropanol, butanol and isobutanol. In a particular embodiment,
the alcohol is ethanol. The alcohol may be a co-solvent mixture
such as a mixture of an alcohol and water. The aqueous alcoholic
solution may comprise from 0-100% (v/v) alcohol. More particularly,
the aqueous alcoholic solution may comprise from 25-95% (v/v)
alcohol. In a particular embodiment, the aqueous alcoholic solution
is 25% (v/v) or more alcohol. In another particular embodiment, the
aqueous alcohol may be 60% (v/v) alcohol. In another embodiment,
the aqueous alcoholic solution may be 70% (v/v) alcohol. In yet
another embodiment, the aqueous alcoholic solution may be 86% or
more (v/v) alcohol. In yet other embodiments, the process for
fractionating or extracting biomass may comprise contacting the
biomass with glycerin or an aqueous glycerin solution. In yet
another embodiment, the process for extracting biomass may comprise
contacting the biomass with water. Typically, in other embodiments
of the invention, the ratio of biomass/solids contacted with a
solvent/liquids used may be 1:1 to 1:10 of solids to liquid. During
contact with the solvent (alcohol or water) the fibers of the
biomass may swell.
[0033] With respect to disassembling the fibers, the fibers are
opened up by chopping, cutting, fraying, attrition or crushing the
biomass and are thereby provided in a fluidized or flowable form.
For example, the biomass fibers may be processed in a mechanical
high consistency fluidization machine such as a refiner or disk
mill. An exemplary disk mill is available from Sprout Waldron,
Beloit or Andritz. By utilizing a refiner or disk mill, the biomass
and particularly the fibrous material thereof may be altered
without destroying the fibrous nature of the fibrous material so
that the high frequency pulses and shear forces of the
fractionation apparatus are accessible to the fibrous material. The
processing may take place for any amount of time necessary as would
be understood by one of skill in the art as necessary to affect
this step. In a particular embodiment, the disassembly process is
performed for one minute or less.
[0034] The overall pretreatment step 90 may take place for any
period of time that is sufficient for the fractionation or
extraction process and may take place in any vessel, container or
mixer suitable for contacting the biomass with a solvent and/or
disassembling the fibers. In some embodiments, the pretreatment
step may be any length of time between, for example, 15 minutes, 30
minutes or one hour, and 72 hours. In another embodiment, the
pretreatment step may be 15 minutes or less. The pretreatment step
may be one minute or less. In the pretreatment step, the biomass in
contact with the solvent may optionally be subjected to a
compressive force, which can facilitate absorption of the solvent
into the biomass. The compression in the pretreatment step 90 may
take place according to any technique that will be appreciated by
one of skill in the art. In an embodiment of the invention,
compression during the pretreatment step may be affected by a screw
press.
[0035] In another embodiment, the pretreatment may include the
addition of an acid to prehydrolyze the biomass to facilitate
removal of the hemicellulose. Suitable acids for acidifying the
pretreatment solution (solvent) include inorganic acids such as
nitric acid, hydrochloric acid and phosphoric acids, and organic
acids, such as acetic acid or formic acid. If
acidification/hydrolysis is desired, the pH of the solution will be
about 0.5 to 7.0 and often may be between about 1.0 to 5.0. A
sequestering agent or chelating agent such as an aminocarboxylic
acid or aminopolyphosphoric acid may also be used.
[0036] Additionally a compound to help catalyze delignification may
be included. In one embodiment, an anthraquinone (AQ) may be
utilized. Exemplary anthraquinones and derivatives thereof
including 1-methylanthraquinone, 2-methylanthraquinone,
2-ethylanthraquinone, 2-methoxyanthraquinone,
2,3-dimethylanthraquinone, and 2,7-dimethylanthraquinone.
[0037] In another embodiment an alkaline buffer such as an alkaline
metal hydroxide, carbonate phosphate or boron may be included to
facilitate separation of the hemicellulose and lignin individual
components. Suitable hydroxides include sodium hydroxide, sodium
carbonate, and sodium borate. Mixtures or blends of the hydroxides
may be used. If an alkaline metal hydroxide is added, the pH may be
between about 7.0 to 13.0 and often may be between about 8.0 to
11.0.
[0038] The pretreatment step 90 may be conducted at ambient
temperature, elevated temperature (30.degree. C. to 90.degree. C.)
or using steam/vapor (greater than 100.degree. C.). It is
recognized that the vapor may be of the solvent.
[0039] Overall the desire is to provide the fibers in a form
wherein the components of the fibers can be readily fractionated
using the high shear forces and pulses of the fractionation
apparatus. The selection of the conditions of the pretreatment step
90 such as solvent choice, temperature, pressure, time, additives,
and the like will be dependent on the biomass and the components of
that biomass to be fractionated and isolated, and will be within
the skill of one in the art without undue experimentation.
[0040] Following disassembly 110, the biomass is in fluid or
flowable form may be subjected to fractionation 120 to fractionate
or extract the biomass using shear forces and pulsation. It will be
appreciated that in a particular embodiment, shear forces and
pulsation are used in which the components of the biomass are not
denatured or altered, and the chemical properties of the individual
components are maintained wherein a portion of the fractions or
extracts may be separated from the biomass. The subjecting of the
biomass to shear forces and high frequency pulses may take place
for any amount of time necessary as would be appreciated by one of
skill in the art as necessary to affect this step. In a particular
embodiment, this step may take place for one minute or less. In
operation the fluidized biomass is rapidly accelerated from about 4
mph to about 120 mph under greater than 1000 pulses per second of
energy while avoiding attrition of the biomass particles. This
facilitates the ability of the cellular structure of the biomass to
release its various fractions or constituents from the complex and
entangled structure of the biomass without having the chemical
properties and characteristics of the components being
denatured.
[0041] The fractionated biomass material may then be subjected to a
compression force 130 e.g., a crushing or macerating force
optionally in the presence of additional solvent, wherein the
compression force removes liquid fraction for collection while
discharging a low liquid solids cake primarily being cellulose. The
compression force may be applied according to any technique that is
appreciated by one of skill in the art. In a particular embodiment,
the compression force is affected by screws of a screw press that
macerate the fractionated biomass.
[0042] The steps of subjecting to fractionation 120 and subjecting
to fractionation can continue until the biomass fraction is
substantially free of hemicellulose and sugars. This can be
monitored or measured in a wide variety of matters including using
a brix meter to measure sugar content, differential scanning
calorimeter (DSC) to measure melt temperatures and differential
thermal analysis (DTA) to measure area under melt curves.
[0043] The fractions or extracts provided according to the present
invention may be further processed as outlined in FIG. 2. The
fractions or extracts provided according to the present invention
may be further processed as outlined in FIG. 2. The screened
liquids (e.g., liquid fractions) can be contacted with additional
biomass, the biomass disassembled 210, fractionated 220, screened
240, subjected to a compressive force 230, and the solid
fractionated biomass primarily being cellulosic and the liquid
fractionated product stream separated 250. The fractionated biomass
is high in cellulose can be used to make pulp and paper.
[0044] Once the fractionated biomass is substantially free of
hemicellulose and sugars, the biomass is subjected to oxidation at
a pH above 7. In one embodiment, oxidation occurs by contacting the
fractionated biomass with 0.1 to 1.5 percent hydrogen peroxide. For
example, with respect to lignin separation, isolation, and
purification, the hydrogen peroxide allows the lignin ether bond to
cleave. Specifically, the phenolic groups in the lignin are ionized
and the resulting radical is mainly of the phenoxyl radical type.
Then hydrogen peroxide is formed through dismutation of the
superoxide anion. The superoxide anion itself is not very reactive
but the decomposition products of hydrogen peroxide include the
very reactive hydroxyl radical. The hydroxyl radical not only
reacts with the lignin structures but also readily attacks the
polysaccharides with subsequent glycosidic bond cleavage and the
creation of new sites for peeling reactions. Once the perhydoxyl
radical attaches to the lignin (or protein or water insoluble
extractive) these individual components of the biomass become more
polar and water soluble. Other oxidation agents include alkali
metal peroxides such as organic and inorganic peroxides including
sodium peroxide, calcium peroxide, and magnesium peroxide. Moreover
this reaction can be facilitated by inclusion of anthraquinone or
its derivatives or other catalysts in the pretreatment step.
[0045] After separation, the now water soluble individual
components can be further separated, isolated and/or purified. In
one embodiment, the centrifugation is used to provide a leant.
Then, for example, ultrafiltration or diafiltration membranes,
available from Millipore, Billerica, Mass., may be used. A first
membrane can be used to remove any remaining hemicellulose from the
liquid fraction, in one embodiment, the first membrane is a 10K
dalton screen. The retentate will comprise the hemicellulose and
the permeate will primarily comprise lignins, proteins, and
extractives with a small amount of hemicellulose, sugars, and fiber
fragments. The second membrane will isolate the lignin, protein or
extractive depending on the membrane as a retentate and any
remaining hemicellulose, sugars, fragments, contaminants (e.g.,
heavy metals) as the permeate. In one embodiment, the second
membrane is an 8K dalton screen. A further 3K dalton screen can be
used to further isolate the desired component.
[0046] In a particular embodiment, the cellulose and/or cellulose
pulp provided by the fractionation and/or extraction process of the
present invention can be used or applied in the preparation of
paper and paper products. Examples of paper products include, but
are not limited to: paper; paperboard; and card stock. Use of the
paper products prepared from the cellulose and/or cellulose pulp
provided by the present invention is not particularly limited. The
paper products can be produced with a wide variety of properties,
depending on its intended use, which range from, for example:
representing value, such as in paper money, bank notes, checks,
security, vouchers and tickets; for storing information, such as in
books and notebooks, scrapbooks, magazines, newspapers, art,
letters; for personal use, such as in diaries, notes to oneself,
etc. and scratch paper; for communication, such as in communication
between individuals and/or groups of people; for packaging and
containers, such as in paperboard, kraft board, containerboard,
linerboard, beverage and/or food containers, liquid containers,
corrugated boxes, paper bags, envelopes, wrapping tissue, Charta
emporetica and wallpaper; for cleaning, such as in toilet paper,
handkerchiefs, paper towels, facial tissue and cat litter; for
construction, such as in papier-mache, origami, paper planes,
quilling, paper honeycomb, used as a core material in composite
materials, paper engineering, construction paper and paper
clothing; and other uses, such as in emery paper, sandpaper,
blotting paper, litmus paper, universal indicator paper, paper
chromatography, electrical insulation paper (see also dielectric
and permittivity) and filter paper.
[0047] The method by which the cellulose and/or cellulose pulp
provided by the present invention is used in the production of
paper and paper products is not particularly limited, and any
method that would be appreciated by one of skill in the art may be
used in the production of paper and paper products using the
cellulose and/or cellulose pulp provided by the present invention.
For example, the cellulose pulp provided according to the present
invention can be fed to a paper machine where it is formed as a
paper web and the water is removed from it by pressing and drying.
The cellulose pulp provided by the present invention may also be
bleached to make the pulp whiter. Typical chemicals and processes
used in the bleaching of pulp include: chlorine; sodium
hypochlorite; extraction with sodium hydroxide; oxygen; alkaline
hydrogen peroxide; ozones; chelation to remove metals; enzyme
treatment; peroxy acids; and sodium dithionite. Typical chelation
agents include, but are not limited to, EDTA and DTPA. Although not
particularly limited by the method of bleaching of the cellulose
and/or cellulose pulp provided by the present invention, elemental
chlorine free (ECF) and/or total chlorine free (TCF) methods of
bleaching provide more environmentally friendly methods of
bleaching. TCF bleaching, for example, prevents the formation of
toxic chemicals such as dioxins. An example of a TCF sequence for
the bleaching of pulp is wherein the pulp would be treated with
oxygen, then ozone, washed with sodium hydroxide then treated in
sequence with alkaline peroxide and sodium dithionite.
[0048] In other embodiments, the cellulose and/or cellulose pulp
provided according to the present invention can be used or applied
in the preparation and/or manufacture of paper coatings. Cellulose
and cellulose derivatives have been used to coat papers to enhance
physical characteristics, for example, but not limited to,
appearance, e.g., glossiness and finish, strength, rigidity and
water resistance. The manner in which the paper coatings prepared
from the cellulose and/or cellulose pulp provided according to the
present invention is not limited and the method used may be any
that would be appreciated by one of skill in the art.
[0049] In yet other embodiments, the cellulose and/or cellulose
pulp provided according to the present invention can be used in the
preparation of fibers. Examples of fibers include, but are not
limited to, regenerated cellulose fibers, for example, cellophane
and rayon.
[0050] In yet other embodiments, the cellulose and/or cellulose
pulp provided according to the present invention can be used in
consumables. The type of consumable is not particularly limited,
and applications can include, but are not limited to:
microcrystalline cellulose or powdered cellulose used as inactive
fillers in drug tablets; thickeners and/or stabilizers Powdered
cellulose may also be used to improve characteristics of processed
foods or foodstuffs, for example, to prevent caking and/or clumping
of the processed food or foodstuffs within a container.
[0051] In yet other embodiments, the cellulose and/or cellulose
pulp provided according to the present invention can be used in
scientific applications. Cellulose is commonly used in the
laboratory as the stationary phase for chromatography, in
particular, thin layer chromatography. Liquid and gel filtration
typically use products prepared from cellulose, either alone or in
combination with other filtration media, for example, diatomaceous
earth.
[0052] In yet other embodiments, the cellulose and/or cellulose
pulp provided according to the present invention can be used in
construction and building materials. Cellulose insulation made from
recycled paper is becoming popular as an environmentally preferable
material for building insulation. It can be treated with boric acid
as a fire retardant. Moreover, hydrogen bonding of cellulose in
water can produce a sprayable, moldable material as an alternative
to the use of plastics and resins. The recyclable material can be
made water and/or flame-resistant or fire retardant, and can
provide sufficient strength for use as a building material.
[0053] In another embodiment, the cellulose can be treated with
cellulose enzymes to hydrolyze the crystalline cellulose to glucose
followed by fermentation of the glucose with yeast or suitable
microorganism to provide biofuel and/or bio feedstock. It is
recognized that the hemicellulose and/or sugars previously
separated from the fractionated biomass may be added back to be
co-fermented with the cellulose.
[0054] In another particular embodiment, fractionation or
extraction according to the invention provides hemicelluloses and
sugars. Sugars and/or hemicelluloses provided by the process
according to the invention may further be used in the preparation
of biofuels such as, but not limited to, ethanol or the preparation
of polymers/plastics. One such embodiment is the fermentation of
the provided fractions to produce the ethanol. In another
embodiment, the polymer is polylactic acid (PLA). In another
embodiment the lignin may be further separated and emulsified for
further processing. Because the lignin has not been subjected to
high temperatures, its functional groups have not chemically
reacted and the isolated lignin may be more reactive.
[0055] In another embodiment of the invention, the fraction or
extract isolated and used is lignin. Examples of the applications
and uses of lignin provided by the present invention include, but
are not limited to, for example: cement and concrete; animal feed
pellets; animal feed molasses additives; road binder/dust control;
pesticides; oil well drilling muds; adhesives; resins and binders;
wallboard; dispersants; emulsifiers and wetting agents;
agglomerants; chelants; leather treatment; anti-bacterial activity;
lead acid batteries; oil recovery; water treatment; industrial
cleaners; emulsion stabilizers; carbon black; inks and azo
pigments; dyestuffs; micronutrients; fertilizers; refractories and
ceramic brick additives; ore processing; and kitty litter. In
another embodiment of the invention, the fraction or extract used
is pulp, cellulose and/or cellulose pulp. Examples of the
applications and uses and applications of cellulose and/or
cellulose pulp provided by the present invention include, but are
not limited to, for example: paper and paper products; paper
coatings; fibers; consumables; science; biofuels; building
materials; insulation adhesives; and binders.
[0056] In some embodiments, the lignin provided according to the
present invention may comprise derivatives of lignin or lignin
derivatives, for example, lignosulfonates or lignin amine. In a
further embodiment, the lignin provided by the present invention is
used as a binder. Lignin or lignin derivatives can be used as an
adhesive, serving as a binding agent in pellets or compressed
materials. Lignin or lignin derivatives can be used in dust
control, for example, on unpaved roads to reduce environmental
concerns from airborne dust particles and stabilize the road
surface. The ability of lignin to act as a binder makes lignin
useful as a component in, for example: biodegradable plastic; coal
briquettes; plywood and particle board; ceramics; animal feed
pellets; carbon black; fiberglass insulation; fertilizers and
herbicides; linoleum paste; dust suppressants; and soil
stabilizers.
[0057] In other embodiments, the lignin provided by the present
invention is used as a dispersant. Lignin or lignin derivatives can
prevent the clumping and settling of undissolved particles in
suspensions. Lignin or lignin derivatives can prevent particles in
suspension from being attracted to other particles and can reduce
the amount of water needed to use a product comprising said
particles in suspension. The ability of lignin or lignin
derivatives to act as a dispersant make lignin useful as a
component in, for example: cement mixes; leather tanning; clay and
ceramics; concrete admixtures; dyes and pigments; oil drilling
muds; and pesticides and insecticides.
[0058] In still other embodiments, the lignin provided according to
the present invention is used as an emulsifier. Lignin or lignin
derivatives may stabilize emulsions of immiscible liquids, for
example, oil and water, making them highly resistant to separating.
The ability of lignin, lignosulfates and lignin amine to act as an
emulsifier makes lignin or lignin derivatives a useful component
in, for example: asphalt emulsions; pesticides; pigment and dyes;
and wax emulsions.
[0059] In yet other embodiments, lignin provided according to the
present invention is used as a sequestrant. Lignin or lignin
derivatives can interact with metal ions, preventing them from
reacting with other compounds and becoming insoluble. Metal ions
sequestered with lignin or lignin derivatives stay dissolved in
solution, rendering them available to plants and preventing scaly
deposits in water systems. The ability of lignin and lignin
derivatives to act as a sequestrant makes lignin a useful component
in, for example: micronutrient systems; cleaning compounds; and
water treatments for boilers and cooling systems.
[0060] In a particular embodiment, lignin provided by the present
invention can be used in concrete. Lignin or lignin derivatives can
aid in, for example: high performance concrete strength; concrete
grinding; reducing damage caused by moisture and acid rain; and
retarding cement composition setting. Specifically, lignosulfonates
can contribute higher adsorption properties and zeta potential to
cement particles and provide better dispersion characteristics to
the cement matrix. Lignins can also improve the compressive
strength of cement pastes.
[0061] In another embodiment, lignin provided by the present
invention can be used as an antioxidant. Lignin can act as a free
radical scavenger, and provide thermal protection to, for example,
styrene polymers, butadiene polymers, rubber polymers, rubber,
polypropylene and polycaprolactam. The natural antioxidant
properties of lignin make it useful in cosmetic and topical
formulations, and lignosulfonates have been used in cosmetic
compositions, such as makeup for decorative use and/or correction
on skin.
[0062] In yet another embodiment, lignin provided by the present
invention can be used in asphalt. Examples of uses include crack
filling compositions for asphalt, enhancing water stability of
asphalt, emulsifying agents for asphalt and fluidity modifiers that
decrease production costs of asphalts.
[0063] In another particular embodiment, lignin provided by the
present invention may be applied to and/or used in or with carbon
or graphite fibers, carbon fiber reinforced polymers and carbon
nanotubes.
[0064] In yet another particular embodiment, lignin provided by the
present invention may be applied and used in the production of
fiberboards, particleboards, wood fiber insulation boards,
strawboards, oriented strand boards and the like as part of a
binder composition. For example, a lignin may be added to a resin
to provide a binder with reasonable wet strength. Lignin based
modifiers, wherein lignin or lignosulfonate can be added to
formaldehyde based binder systems, for example, phenol
formaldehyde, urea formaldehyde, melamine formaldehyde, resorcinol
formaldehyde and/or tannin formaldehyde resins. The resulting board
binder may then be used for panel boards, for example, in plywoods,
hard boards, fiberboards or particle boards.
[0065] In another embodiment, lignin provided by the present
invention may be applied and used in foams, plastics and/or
polymers. For example, polyurethanes comprising lignins can have
improved flame resistance and/or fire retardance. Epoxy resins can
comprise a curing agent that comprises a lignin and/or a lignin
derivative, such as a lignin-derived acetic anhydride. Lignins, for
example S-free lignin, can be used in epoxy resins for fabricating
printed circuit boards, or in products, such as automotive brakes.
Lignins may be added to polymers, for example, polyphenylene
oxide-based polymers, to enhance modulus of elasticity, tensile
strength and elongation at break values of the polymer. Lignin can
also act as a water absorption inhibitor and/or as a fluidization
agent to facilitate polymer, for example, polyamide, processing,
such as by injection molding, blow molding, extrusion or blow
extrusion, to fabricate articles when mixed in solid or melt form.
Lignins, for example, alkali lignin poly(propylene carbonate), can
also be used to improve the thermal stability and mechanical
properties of polymers.
[0066] In yet another embodiment, lignin provided by the present
invention may be applied and used in dust control. For example,
lignin and glycerin in water, can be applied to areas in which dust
is a problem, such as, for example, in coal mines, transportation
of coal, railways, roads, stock yards and the like. Lignin, for
example, particular calcium lignin sulfonate powders, have been
shown to stabilize contamination following a nuclear accident. Dust
movement can also be controlled on a road surface by spraying with
an emulsion comprising asphalt, lignosulfonate and water.
[0067] In another particular embodiment, lignin provided by the
present invention may be applied and used in papers as a sizing
agent, to enhance paper tensile strength, and/or as a packaging
laminate.
[0068] In yet another embodiment, lignin provided by the present
invention may be applied and used to provide chemicals through
depolymerization of lignin. Depolymerization of lignin can provide,
for example, phenols, cresols, catechols, resorcinols, quinolines,
vanillin, guaiacols and the like.
[0069] In yet another embodiment, lignin provided by the present
invention may be applied and used in batteries and to enhance the
performance of energy storage devices. For example, graphite powder
in batteries comprising a thin layer of lignin can be used to
prevent the graphite powder from decreasing H overvoltage, while
not affecting the condition of the graphite powder. Lignin can also
be used to protect negative plates of batteries from the formation
of a passivating lead sulfate layer thereon.
[0070] In yet another particular embodiment, lignin provided by the
present invention may be applied and used as a fuel additive, or
can be catalytically converted to gasoline/diesel by a combination
of pyrolysis, thermal cracking, hydrocracking, catalytic cracking
or hydrotreatment. Lignin may further be used in catalytic
hydrothermal gasification to provide fuel gas. Lignin may also be
used to wood pellets to produce better quality pellets with higher
fuel value, or in artificial fire logs to provide improved flame
properties.
[0071] In another embodiment, lignin provided by the present
invention may be applied and used as an additive to improve the
characteristics of lubricants. For example, lignosulfonates can be
used as a thickening agent for lubricating greases. Greases can
comprise lignin compositions to provide improved corrosion
protection properties of the grease. Additionally, greases
comprising lignin, for example, hydrolytic lignin, can provide
greater wear resistance to devices using the same. Greases
comprising lignin, such as lignosulfonate, can improve the
antifriction properties of the grease, and provide longer
lubrication life for the grease.
[0072] In yet another particular embodiment, lignin provided by the
present invention may be applied and used in the production of
latex and/or rubber. For example, lignin can be added to latex
and/or rubber and function as a filler, pigment, modifier, extender
or reinforcement for the same. Lignin added to latex can increase
oil resistance and/or tensile strength of rubber latex films.
Rubbers reinforced with lignin can exhibit improved ozone
resistance compared to rubbers without lignin added. The method by
which the lignin provided by the present invention is incorporated
into latex and/or rubber is not particularly limited, and may be
carried out by in any manner that will be appreciated by one of
skill in the art.
[0073] In another embodiment, the isolated proteins may be further
isolated and hydrolyzed to single amino acids, peptides, and/or
polypeptides. Isolated protein may be used as a food supplement for
humans and animals. The protein content can be measured using
Kjeldehl analysis.
[0074] The following example is provided to illustrate the present
invention, and should not be construed as limiting thereof.
EXAMPLE
Example 1
Wheat Grass
[0075] 10 Kg of dried wheat grass (straw) is chopped to a stalk
length of 3/4 to 2 inches. The straw was briefly rinsed with cold
clean water to remove sand and dirt. The wheat straw is then
subjected to water or steam injection into a disk mill for a few
seconds to mechanically disassemble the cellulosic structure. The
fluidized wheat grass is then subjected to high shear forces for
1.5 to 3 seconds with pulses of 1824 to 912 times without
denaturing the components of the wheat straw. The combined mixture
is subjected to compressive forces to separate the stream into
liquid and a 20-60% cellulosic solids fractions. The liquid
fraction containing hemicellulose is retained.
[0076] The solid fraction is pretreated with NaOH sufficient to
raise the pH of the cellulosic water slurry from about 4-7 to
10-12. This basic mixture is allowed to age from a few seconds to 1
hour and again processed through the system starting at the disk
mill which is subjected to water or steam injection in the mill for
a few seconds to mechanically disassemble the cellulosic structure.
The fluidized wheat grass is then subjected to high shear forces
for 1.5 to 3 seconds with pulses of 1824 to 912 times without
denaturing the components of the wheat straw. The combined mixture
is subjected to compressive forces to separate the stream into
liquid and a 20-60% cellulosic solids fractions. The liquid
fraction containing hemicellulose is added to the first and second
fraction and undergoes further processing.
[0077] The solid fraction is treated with an oxidation agentic
hydrogen peroxide, sufficient to raise the pH of the cellulosic
water slurry from about 10-12 to 8-10. This basic mixture is
allowed to age from a few seconds to 1 hour and again processed
through the system starting at the disk mill which is subjected to
water or steam injection in the mill for a few seconds to
mechanically disassemble the cellulosic structure. The fluidized
wheat grass is then again subjected to high shear forces for 1.5 to
3 seconds with pulses of 1824 to 912 times without denaturing the
components of the wheat straw. The combined mixture is screened and
subjected to compressive forces to separate the stream into liquid
and a 20-60% cellulosic solids fractions. The liquid fraction
containing lignin is retained. The solid fraction is then treated
again to raise the pH and the liquid fraction containing
hemicellulose is added to the first and second fraction and
undergoes further processing. The solid fraction is then treated
with an oxidation agent and rerun through the fractionation unit.
The liquid fraction containing lignin is added to the first liquid
lignin fraction and further separated using a membrane.
[0078] Although selected embodiments of the present invention have
been disclosed for illustrative purposes, those skilled in the art
will appreciate that various modifications, additions and
substitutions are possible, without departing from the scope and
spirit of the invention as disclosed in the accompanying
claims.
* * * * *