U.S. patent application number 14/987054 was filed with the patent office on 2016-04-28 for biomass pretreatment process.
This patent application is currently assigned to Beta Renewables S.p.A.. The applicant listed for this patent is Beta Renewables S.p.A.. Invention is credited to Andrea BONANNI, Francesco CHERCHI, Marco COTTI COMETTINI, Simone FERRERO, Mirko GARBERO, Piero OTTONELLO, Paolo TORRE.
Application Number | 20160115320 14/987054 |
Document ID | / |
Family ID | 42828781 |
Filed Date | 2016-04-28 |
United States Patent
Application |
20160115320 |
Kind Code |
A1 |
GARBERO; Mirko ; et
al. |
April 28, 2016 |
BIOMASS PRETREATMENT PROCESS
Abstract
The process for the treatment of ligno-cellulosic biomass
comprises the steps of: A) Soaking a ligno-cellulosic biomass
feedstock in vapor or liquid water or mixture thereof in the
temperature range of 100 to 210.degree. C. for 1 minute to 24 hours
to create a soaked biomass containing a dry content and a first
liquid; B) Separating at least a portion of the first liquid from
the soaked biomass to create a first liquid stream and a first
solid stream; wherein the first solid stream comprises the soaked
biomass; and C) Steam exploding the first solid stream to create a
steam exploded stream comprising solids and a second liquid.
Inventors: |
GARBERO; Mirko; (Torino,
IT) ; OTTONELLO; Piero; (Genova, IT) ; COTTI
COMETTINI; Marco; (Trivero, IT) ; FERRERO;
Simone; (Tortona, IT) ; TORRE; Paolo;
(Arenzano, IT) ; CHERCHI; Francesco; (Campobasso,
IT) ; BONANNI; Andrea; (Roma, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Beta Renewables S.p.A. |
Tortona |
AL |
US |
|
|
Assignee: |
Beta Renewables S.p.A.
Tortona
AL
|
Family ID: |
42828781 |
Appl. No.: |
14/987054 |
Filed: |
January 4, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13260340 |
Sep 25, 2011 |
9234224 |
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PCT/IB2010/051412 |
Mar 31, 2010 |
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14987054 |
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PCT/IT2009/000125 |
Mar 31, 2009 |
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13260340 |
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PCT/IT2009/000129 |
Mar 31, 2009 |
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PCT/IT2009/000125 |
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PCT/IT2009/000130 |
Mar 31, 2009 |
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PCT/IT2009/000129 |
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Current U.S.
Class: |
252/182.12 |
Current CPC
Class: |
C12P 19/04 20130101;
D21C 5/005 20130101; C12P 19/02 20130101; C08H 8/00 20130101; Y02E
50/16 20130101; C13K 1/02 20130101; C08L 97/02 20130101; Y02E 50/10
20130101; C12P 2201/00 20130101 |
International
Class: |
C08L 97/02 20060101
C08L097/02 |
Claims
1. A composition of ligno-cellulosic biomass comprising a solid, a
liquid, furfural, an amount of C5's based upon the amount of
arabinan and xylan and the monomers, dimers, oligomers and polymers
of arabinose and xylose in the liquid and solid of the composition,
an amount of C6's based upon the glucan content which includes the
monomers, dimers, oligomers and polymers of glucan in the liquid
and solid of the composition and wherein the ratio of the amount of
C5's to the amount of C6's is less than 0.50 or 0.44 and the ratio
of the amount of the furfural to the amount of C5's and C6's added
together is less than a number selected from the group consisting
of 0.0060, 0.0050, 0.0040, 0.0030, 0.0020, 0.0010, and 0.0009.
2. The composition of claim 1, wherein the amount of the solids in
the composition by percent weight of the composition are in a range
selected from the group consisting of 11 to 99, 14 to 99, 16 to 99,
19 to 99, 21 to 99, 24 to 99, 26 to 99, 29 to 99, 31 to 99, 36 to
99, and 41 to 99.
3. The composition of claim 1, wherein the amount of the solids in
the composition are in the range of 3 to 85% by weight of the
composition.
4. A composition of ligno-cellulosic biomass comprising a solid, a
liquid, furfural, an amount of C5's based upon the amount of
arabinan and xylan and the monomers, dimers, oligomers and polymers
of arabinose and xylose in the liquid and solid of the composition,
an amount of C6's based upon the glucan content which includes the
monomers, dimers, oligomers and polymers of glucan in the liquid
and solid of the composition wherein the ratio of the amount of
C5's to the amount of C6's is greater than 0.50 and the ratio of
the amount of the furfural to the amount of C5's and C6's added
together is less than a number selected from the group consisting
of 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, 0.006,
0.005, 0.004, 0.003, 0.002, and 0.001.
5. The composition of claim 4, wherein the amount of the solids in
the composition by percent weight of the composition are in a range
selected from the group consisting of 11 to 99, 14 to 99, 16 to 99,
19 to 99, 21 to 99, 24 to 99, 26 to 99, 29 to 99, 31 to 99, 36 to
99, and 41 to 99.
6. The composition of claim 4, wherein the amount of the solids in
the composition are in the range of 3 to 85% by weight of the
composition.
Description
BACKGROUND
[0001] In the biomass field converting lignocellulosic biomass to
ethanol is a common practice. If the biomass is a
polysaccharide-containing biomass and it is lignocellulosic, a
pre-treatment is often used to ensure that the structure of the
lignocellulosic content is rendered more accessible to the enzymes,
and at the same time the concentrations of harmful inhibitory
by-products such as acetic acid, furfural and hydroxymethyl
furfural are usually high and present problems in further
processing.
[0002] In general terms the more severe the treatment, the more
accessible are the cellulosic contents of the material. The
severity of the steam explosion is known in the literature as Ro,
and is a function of time and temperature expressed as
Ro=te.sup.[(T-100)/14.75]
with temperature, T, expressed in Celsius and time, t, expressed in
common units. The formula is also expressed as Log (Ro), namely
Log (Ro)=Ln(t)+[(T-100)/14.75].
[0003] It is generally considered that a high Ro value is
associated with a high number of unwanted by-products which inhibit
the hydrolysis and fermentation of the biomass, such as
furfural.
[0004] NREL Report No. TP-421-4978, November 1992, McMillan J. D.,
"Processes for Pretreating Lignocellulosic Biomass: A Review" even
affirmed in its conclusions that "steam explosion-based processes .
. . are unattractive in the long run because the formation of
degradation products reduces yields" and exhorted to research
alternative processes, such as ammonia fiber explosion and
supercritical fluid-based treatments.
[0005] There exists therefore, the need to have a severe process
with a high Ro which at the same time produces a product with low
furfural.
SUMMARY
[0006] Disclosed in this specification is a process for the
improved pretreatment of biomass which includes the steps of
soaking a biomass feedstock in vapor or liquid water in the
temperature range of 100 to 210.degree. C., preferably 140 to
210.degree. C., for 1 minute to 24 hours, preferably 1 minute to 16
hours, more preferably 1 minute to 2.5 hours, and most preferably 1
minute to 2 hours to create a soaked biomass containing a dry
content and a first liquid; separating at least a portion of the
first liquid from the soaked biomass to create a first liquid
stream and a first solid stream, wherein the first solid stream
comprises the soaked biomass; steam exploding the first solid
stream to create a steam exploded stream comprising solids and a
second liquid; optionally separating at least some of the second
liquid from the steam exploded stream to create a second liquid
stream and a second solid stream. It is also disclosed that the
process may comprises the further step of combining at least a
portion of the liquid of the first liquid stream with the second
solid stream.
[0007] A third optional step is also disclosed in which the steam
exploded stream is washed with at least a third liquid to create a
third liquid stream prior to introduction of the steam exploded
stream into the separation step.
[0008] A further purification step is disclosed wherein the first
liquid stream is purified to create a first purified liquid stream
prior to combining the first liquid stream with the second solid
stream.
[0009] A further step is disclosed wherein the second liquid stream
is purified to create a second purified liquid stream and then the
second purified liquid stream is combined with the second solid
stream.
[0010] It is further disclosed to purify the third liquid stream
and then combine it with the second solid stream.
[0011] Pressing is disclosed as a way to separate the liquid from
the soaked biomass.
[0012] Flashing is disclosed as a step to purify the first liquid
stream. It is further disclosed that this flashing be done without
reducing the pressure of the first liquid stream to atmospheric
pressure before flashing. It is further disclosed that the flashing
be done at the pressure of the first liquid stream at the end of
separating the first liquid from the soaked biomass.
[0013] Steam stripping of any and all of the liquid streams in
combination or separately is disclosed. Using the steam from steam
explosion step and/or the soaking step is also disclosed.
[0014] Purification of any of the liquid streams with activated
charcoal is also disclosed. It is also disclosed to concentrate the
streams to remove water. It is also disclosed that the streams can
be combined after at least a portion of the second solid stream has
been hydrolyzed.
[0015] Also disclosed in this specification is a novel composition
from the process comprising a solid, a liquid, an amount of C5's
based upon the amount of arabinan and xylan and the monomers,
dimers, oligomers and polymers of arabinose and xylose in the
liquid and solid of the composition, an amount of C6's based upon
the glucan content which includes the monomers, dimers, oligomers
and polymers of glucan in the liquid and solid of the composition
and furfural wherein the ratio of the amount of C5's to the amount
of C6's is less than 0.50 and the ratio of amount of the furfural,
which is always present in the composition to the amount of C5's
and C6's added to together is between 0 and 0.0140, also expressed
as greater than 0 and less than 0.0140; is between 0 and 0.0100,
also expressed as greater than 0 and less than 0.0100; is between 0
and 0.0060, also expressed as greater than 0 and less than 0.0060;
is between 0 and 0.0040, also expressed as greater than 0 and less
than 0.0040; 0 and 0.0030, also expressed as greater than 0 and
less than 0.0030; 0 and 0.0020, also expressed as greater than 0
and less than 0.0020; 0 and 0.0010, also expressed as greater than
0 and less than 0.0010; or between 0 and 0.0009, also expressed as
greater than 0 and less than 0.0009. It is further disclosed that
the ratio of the amount of C5's to the amount of C6's is less than
0.44.
[0016] Another novel composition of biomass is disclosed comprising
a solid, a liquid, an amount of C5's based upon the amount of
arabinan and xylan and the monomers, dimers, oligomers and polymers
of arabinose and xylose in the liquid and solid of the composition,
an amount of C6's based upon the glucan content which includes the
monomers, dimers, oligomers and polymers of glucan in the liquid
and solid of the composition and furfural wherein the ratio of the
amount of C5's to the amount of C6's is greater than 0.50 and the
ratio of amount of the furfural to the amount of C5's and C6's
added to together is any of the ranges of between 0 and 0.09, also
expressed as greater than 0 and less than 0.09; between 0 and
0.0060, also expressed as greater than 0 and less than 0.0060;
between 0 and 0.0050, also expressed as greater than 0 and less
than 0.0050; between 0 and 0.0040; between 0 and 0.0030, also
expressed as greater than 0 and less than 0.0030 and between 0 and
0.0016, also expressed as greater than 0 and less than 0.0016.
[0017] It is further disclosed that the amount of solids by total
weight of either of the novel compositions be in any of the ranges
of 3 to 85%, 3 to 65%, 3 to 20% 11 to 99%; 14 to 99%; 16 to 99%; 19
to 99%; 21 to 99%; 24 to 99%; 26 to 99%; 29 to 99%; 31 to 99%; 36
to 99%; and 41 to 99%.
BRIEF DESCRIPTION OF FIGURES
[0018] FIG. 1 is a schematic of an embodiment of the process.
[0019] FIG. 2 is a schematic of a second embodiment of the
process.
[0020] FIG. 3 is a schematic of a third embodiment of the
process.
[0021] FIG. 4 is a schematic of a fourth embodiment of the
process.
[0022] FIG. 5 is a schematic of a fifth embodiment of the
process.
[0023] FIG. 6 is a schematic of a sixth embodiment of the
process.
[0024] FIG. 7 is a schematic of a seventh, embodiment of the
process.
[0025] FIG. 8 is a schematic of an eighth embodiment of the
process.
[0026] FIG. 9 is a schematic of a ninth embodiment of the
process.
DETAILED DESCRIPTION
[0027] In all instances of this text, the word "stream" is used to
mean that it is comprised of the material as well. For instance,
the second liquid stream would be comprised of the second liquid,
the second purified liquid stream is comprised of the second
purified liquid. Combining streams means the materials in the
streams are mixed.
[0028] The process acts upon a feedstock in a feedstock stream. The
feedstock stream is comprised of biomass having a dry content and
water. Usually the water is not free water, but is water absorbed
into the biomass itself. This biomass is often expressed according
to its dry content (non-water). A 20% dry content biomass
corresponds to a biomass that has 80% water and 20% non-water, or
otherwise solid content. The term biomass and water is the dry
content of the biomass plus the absorbed and free water and water
which may have been added. For example, the amount of biomass plus
water for 100 kg of biomass with 20% dry content is 100 kg. The
amount of biomass plus water for 100 kg of biomass with 20% dry
content plus 10 kg of water is 110 kg.
[0029] The process described is believed capable of utilizing a
feedstock stream of biomass and water where the dry matter content
to water of the feedstock stream is preferably 20-80%, or 21-80%,
preferably 25-70%, or 26-70%, more preferably 25-60%, or 26-60%,
even more preferably 25-50%, or 26-50% or 25-40%, or 26% to 40% and
most preferably 25-35%, or 26-35%, or 26-34%, or 31%-49%.
[0030] After treatment, the amount of solids by total weight of the
compositions can be in any of the ranges of 3 to 85%, 3 to 85%, 3
to 65%, 3 to 20%, 11 to 99%; 14 to 99%; 16 to 99%; 19 to 99%; 21 to
99%; 24 to 99%; 26 to 99%; 29 to 99%; 31 to 99%; 36 to 99%; and 41
to 99%.
[0031] This can alternatively be expressed as a minimum dry
content, i.e. as a weight percent of the dry content relative to
the water in the feedstock stream. This would correspond to at
least 20 weight percent dry content, preferably at least 25 weight
percent dry content, more preferably at least 30 weight percent dry
content, and most preferably at least 40 weight percent dry
content. The upper limit of these contents is by definition 100%,
but in practice 80 weight percent would be the upper limit to these
contents if they were expressed in ranges.
[0032] Therefore, ranges suitable for this invention are biomasses
having dry contents of greater than 3%, 15%, 20%, 21%, 25%, 26%,
30%, 31%, 35%, 36%, 40%, 50%, 60% and 80% with an upper limit of
100% or 90% for each lower limit.
[0033] The distribution of fiber and particle sizes of the biomass
may involve the ranges of 0-150 mm, preferably, 5-125 mm, more
preferably, 10-100 mm, even more preferably 15-30 to 90 mm or 20-80
mm and most preferably 26 to 70 mm.
[0034] The preferred distribution of fiber and particle sizes is
defined as at least 20% (w/w) of the biomass ranging within the
preferred interval.
[0035] Plant biomass is a preferred feedstock. Apart from starch
the three major constituents in plant biomass are cellulose,
hemicellulose and lignin, which are commonly referred to by the
generic term lignocellulose. Polysaccharide-containing biomasses as
a generic term include both starch and lignocellulosic biomasses.
Therefore, some types of feedstocks can be plant biomass,
polysaccharide containing biomass, and lignocellulosic biomass. A
typical lignocellullosic biomass will contain cellulose, with
amounts being at least 5 percent by weight of the total amount of
dry biomass, with at least 10% and 20% by weight of the total
amount of dry biomass. The ligno-cellulosic biomass may also
contain starch in the amounts preferably less than 50% by weight,
with less than 45, 35 and 15 weight percents even more
preferred.
[0036] If the biomass is a polysaccharide-containing biomass and it
is lignocellulosic, a pre-treatment is often used to ensure that
the structure of the lignocellulosic content is rendered more
accessible to the enzymes, and at the same time the concentrations
of harmful inhibitory by-products such as acetic acid, furfural and
hydroxymethyl furfural remain substantially low.
[0037] Polysaccharide-containing lignocellulosic biomasses
according to the present invention include any material containing
polymeric sugars e.g. in the form of starch as well as refined
starch, cellulose and hemicellulose.
[0038] Relevant types of cellulosic biomasses and polysaccharide
ligno-cellusosic biomasses for hydrolysis and pretreatment
according to the present invention may include biomasses derived
from grasses and more specifically agricultural crops such as e.g.:
starch e.g. starch containing grains and refined starch; corn
stover, bagasse, straw e.g. from rice, wheat, rye, oat, barley,
rape, sorghum; softwood e.g. Pinus sylvestris, Pinus radiate;
hardwood e.g. Salix spp. Eucalyptus spp.; tubers e.g. beet, potato;
cereals from e.g. rice, wheat, rye, oat, barley, rape, sorghum and
corn; waste paper, fiber fractions from biogas processing, manure,
residues from oil palm processing, municipal solid waste or the
like with a similar dry matter content.
[0039] The ligno-cellulosic biomass feedstock is preferably from
the family usually called grasses. The proper name is the family
known as Poaceae or Gramineae in the Class Liliopsida (the
monocots) of the flowering plants. Plants of this family are
usually called grasses, or, to distinguish them from other
graminoids, true grasses. Bamboo is also included. There are about
600 genera and some 9,000-10,000 or more species of grasses (Kew
Index of World Grass Species).
[0040] Poaceae includes the staple food grains and cereal crops
grown around the world, lawn and forage grasses, and bamboo.
Poaceae generally have hollow stems called culms, which are plugged
(solid) at intervals called nodes, the points along the culm at
which leaves arise. Grass Leaves are usually alternate, distichous
(in one plane) or rarely spiral, and parallel-veined. Each leaf is
differentiated into a lower sheath which hugs the stem for a
distance and a blade with margins usually entire. The leaf blades
of many grasses are hardened with silica phytoliths, which helps
discourage grazing animals. In some grasses (such as sword grass)
this makes the edges of the grass blades sharp enough to cut human
skin. A membranous appendage or fringe of hairs, called the ligule,
lies at the junction between sheath and blade, preventing water or
insects from penetrating into the sheath.
[0041] Grass blades grow at the base of the blade and not from
elongated stem tips. This low growth point evolved in response to
grazing animals and allows grasses to be grazed or mown regularly
without severe damage to the plant.
[0042] Flowers of Poaceae are characteristically arranged in
spikelets, each spikelet having one or more florets (the spikelets
are further grouped into panicles or spikes). A spikelet consists
of two (or sometimes fewer) bracts at the base, called glumes,
followed by one or more florets. A floret consists of the flower
surrounded by two bracts called the lemma (the external one) and
the palea (the internal). The flowers are usually hermaphroditic
(maize, monoecious, is an exception) and pollination is almost
always anemophilous. The perianth is reduced to two scales, called
lodicules, that expand and contract to spread the lemma and palea;
these are generally interpreted to be modified sepals. This complex
structure can be seen in the image on the left, portraying a wheat
(Triticum aestivum) spike.
[0043] The fruit of Poaceae is a caryopsis in which the seed coat
is fused to the fruit wall and thus, not separable from it (as in a
maize kernel).
[0044] There are three general classifications of growth habit
present in grasses; bunch-type (also called caespitose),
stoloniferous and rhizomatous.
[0045] The success of the grasses lies in part in their morphology
and growth processes, and in part in their physiological diversity.
Most of the grasses divide into two physiological groups, using the
C3 and C4 photosynthetic pathways for carbon fixation. The C4
grasses have a photosynthetic pathway linked to specialized Kranz
leaf anatomy that particularly adapts them to hot climates and an
atmosphere low in carbon dioxide.
[0046] C3 grasses are referred to as "cool season grasses" while C4
plants are considered "warm season grasses". Grasses may be either
annual or perennial. Examples of annual cool season are wheat, rye,
annual bluegrass (annual meadowgrass, Poa annua and oat). Examples
of perennial cool season are orchardgrass (cocksfoot, Dactylis
glomerata), fescue (Festuca spp), Kentucky Bluegrass and perennial
ryegrass (Lolium perenne).
[0047] Examples of annual warm season are corn, sudangrass and
pearl millet. Examples of Perennial Warm Season are big bluestem,
indiangrass, bermudagrass and switchgrass.
[0048] One classification of the grass family recognizes twelve
subfamilies: These are 1) anomochlooideae, a small lineage of
broad-leaved grasses that includes two genera (Anomochloa,
Streptochaeta); 2) Pharoideae, a small lineage of grasses that
includes three genera, including Pharus and Leptaspis; 3)
Puelioideae a small lineage that includes the African genus Puelia;
4) Pooideae which includes wheat, barely, oats, brome-grass
(Bronnus) and reed-grasses (Calamagrostis); 5) Bambusoideae which
includes bamboo; 6) Ehrhartoideae, which includes rice, and wild
rice; 7) Arundinoideae, which inludes the giant reed and common
reed 8) Centothecoideae, a small subfamily of 11 genera that is
sometimes included in Panicoideae; 9) Chloridoideae including the
lovegrasses (Eragrostis, ca. 350 species, including teff),
dropseeds (Sporobolus, some 160 species), finger millet (Eleusine
coracana (L.) Gaertn.), and the muhly grasses (Muhlenbergia, ca.
175 species); 10) Panicoideae including panic grass, maize,
sorghum, sugar cane, most millets, fonio and bluestem grasses. 11)
Micrairoideae; 12) Danthoniodieae including pampas grass; with Poa
which is a genus of about 500 species of grasses, native to the
temperate regions of both hemispheres.
[0049] Agricultural grasses grown for their edible seeds are called
cereals. Three common cereals are rice, wheat and maize (corn). Of
all crops, 70% are grasses.
[0050] Sugarcane is the major source of sugar production. Grasses
are used for construction. Scaffolding made from bamboo is able to
withstand typhoon force winds that would break steel scaffolding.
Larger bamboos and Arundo donax have stout culms that can be used
in a manner similar to timber, and grass roots stabilize the sod of
sod houses. Arundo is used to make reeds for woodwind instruments,
and bamboo is used for innumerable implements.
[0051] Therefore a preferred lignocellulosic biomass is selected
from the group consisting of the grasses. Alternatively phrased,
the preferred lignocellulosic biomass is selected from the group
consisting of the plants belonging to the Poaceae or Gramineae
family.
[0052] If the polysaccharide-containing biomasses are
lignocellulosic, the material may be cut into pieces where 20%
(w/w) of the biomass preferably ranges within 26-70 mm, before
pre-treatment. The pre-treated material has preferably a dry matter
content above 20% before entering the process. Besides liberating
the carbohydrates from the biomass, the pre-treatment process
sterilizes and partly dissolves the biomass and at the same time
washes out potassium chloride from the lignin fraction.
[0053] The biomass will contain some compounds which are
hydrolysable into a water-soluble species obtainable from the
hydrolysis of the biomass. For example, cellulose can be hydrolyzed
into glucose, cellobiose, and higher glucose polymers and includes
dimers and oliogmers. Cellulose is hydrolyzed into glucose by the
carbohydrolytic cellulases. The prevalent understanding of the
cellulolytic system divides the cellulases into three classes;
exo-1,4-.beta.-D-glucanases or cellobiohydrolases (CBH) (EC
3.2.1.91), which cleave off cellobiose units from the ends of
cellulose chains; endo-1,4-.beta.-D-glucanases (EG) (EC 3.2.1.4),
which hydrolyse internal .beta.-1,4-glucosidic bonds randomly in
the cellulose chain; 1,4-.beta.-D-glucosidase (EC 3.2.1.21), which
hydrolyses cellobiose to glucose and also cleaves off glucose units
from cellooligosaccharides. Therefore, if the biomass contains
cellulose, then glucose is a water soluble hydrolyzed species
obtainable from the hydrolysis of the biomass.
[0054] By similar analysis, the hydrolysis products of
hemicellulose are water soluble species obtainable from the
hydrolysis of the biomass, assuming of course, that the biomass
contains hemicellulose. Hemicellulose includes xylan,
glucuronoxylan, arabinoxylan, glucomannan, and xyloglucan. The
different sugars in hemicellulose are liberated by the
hemicellulases. The hemicellulytic system is more complex than the
cellulolytic system due to the heterologous nature of
hemicellulose. The systems may involve among others,
endo-1,4-.beta.-D-xylanases (EC 3.2.1.8), which hydrolyse internal
bonds in the xylan chain; 1,4-.beta.-D-xylosidases (EC 3.2.1.37),
which attack xylooligosaccharides from the non-reducing end and
liberate xylose; endo-1,4-.beta.-D-mannanases (EC 3.2.1.78), which
cleave internal bonds; 1,4-.beta.-D-mannosidases (EC 3.2.1.25),
which cleave mannooligosaccharides to mannose. The side groups are
removed by a number of enzymes; such as .alpha.-D-galactosidases
(EC 3.2.1.22), .alpha.-L-arabinofuranosidases (EC 3.2.1.55),
.alpha.-D-glucuronidases (EC 3.2.1.139), cinnamoyl esterases (EC
3.1.1.-), acetyl xylan esterases (EC 3.1.1.6) and feruloyl
esterases (EC 3.1.1.73).
[0055] Referring to FIG. 1, the first step in the process is the
soaking of a biomass feedstock stream 1 in a substance such as
water in either vapor form, steam, or liquid form or liquid and
steam together, labeled stream 2, to produce a product 3. The
product 3 is a soaked biomass containing a first liquid, with the
first liquid usually being water in its liquid or vapor form or
some mixture.
[0056] This soaking can be done by any number of techniques that
expose a substance to water, which could be steam or liquid or
mixture of steam and water, or, more in general, to water at high
temperature and high pressure. The temperature should be in one of
the following ranges: 145 to 165.degree. C., 120 to 210.degree. C.,
140 to 210.degree. C., 150 to 200.degree. C., 155 to 185.degree.
C., 160 to 180.degree. C. Although the time could be lengthy, such
as up to but less than 24 hours, or less than 16 hours, or less
than 12 hours, or less than 9 hours or less than 6 hours; the time
of exposure is preferably quite short, ranging from 1 minute to 6
hours, from 1 minute to 4 hours, from 1 minute to 3 hours, from 1
minute to 2.5 hours, more preferably 5 minutes to 1.5 hours, 5
minutes to 1 hour, 15 minutes to 1 hour.
[0057] If steam is used, it is preferably saturated, but could be
superheated. The soaking step can be batch or continuous, with or
without stirring. Another embodiment is shown in FIG. 9, which has
a low temperature soak prior to the high temperature soak. The
temperature of the low temperature soak is in the range of 25 to
90.degree. C. Although the time could be lengthy, such as up to but
less than 24 hours, or less than 16 hours, or less than 12 hours,
or less than 9 hours or less than 6 hours; the time of exposure is
preferably quite short, ranging from 1 minute to 6 hours, from 1
minute to 4 hours, from 1 minute to 3 hours, from 1 minute to 2.5
hours, more preferably 5 minutes to 1.5 hours, 5 minutes to 1 hour,
15 minutes to 1 hour.
[0058] This low temperature soak is shown in FIG. 9 with 31 being
the biomass feedstock, 32 is the water or liquid, 33 is the low
temperature soaked biomass. 34 is the liquid, and would be a fourth
liquid stream that has been separated from the low temperature
soaked biomass with 1 being the biomass feedstock after low
temperature soaking.
[0059] Either soaking step could also include the addition of other
compounds, e.g. H.sub.2SO.sub.4, NH.sub.3, in order to achieve
higher performance later on in the process.
[0060] The product 3 comprising the first liquid is then passed to
a separation step where the first liquid is separated from the
soaked biomass. The liquid will not completely separate so that at
least a portion of the liquid is separated, with preferably as much
liquid as possible in an economic time frame. The liquid from this
separation step is known as the first liquid stream comprising the
first liquid, labeled 5 in FIG. 1. The first liquid will be the
liquid used in the soaking, generally water and the soluble species
of the feedstock. As shown in the Tables 1 through 16, these water
soluble species are glucan, xylan, galactan, arabinan,
glucolygomers, xyloolygomers, galactolygomers and arabinolygomers.
The solid biomass, labeled 4, is called the first solid stream as
it contains most, if not all, of the solids.
[0061] The separation of the liquid can again be done by known
techniques and likely some which have yet been invented. A
preferred piece of equipment is a press, as a press will generate a
liquid under high pressure which is useful as described later.
[0062] The first solid stream 4 is then steam exploded to create a
steam exploded stream 6. Steam explosion is a well known technique
in the biomass field and any of the systems available today and in
the future are believed suitable for this step. The severity of the
steam explosion is known in the literature as Ro, and is a function
of time and temperature and is expressed as
Ro=te.sup.[(T-100)/14.75]
with temperature, T expressed in Celsius and time, t, expressed in
common units.
[0063] The formula is also expressed as Log(Ro), namely
Log(Ro)=Ln(t)+[(T-100)/14.75].
[0064] As disclosed in the operating conditions below, this process
will produce a solids composition under a high Ro, and that is
novel in its low furfural content. As shown in the data, furfural
is not a naturally occurring compound in biomass. Furfural is made
when the biomass is exposed to high temperatures.
[0065] Log(Ro) is preferably in the ranges of 2.8 to 5.3, 3 to 5.3,
3 to 5.0 and 3 to 4.3.
[0066] The steam exploded stream may be optionally washed at least
with water and there may be other additives used as well. It is
conceivable that another liquid may used in the future, so water is
not believed to be absolutely essential. At this point, water is
the preferred liquid and if water is used, it is considered the
third liquid. The liquid effluent from the optional wash is the
third liquid stream 8. Although shown in the drawing accompanying
this specification, this wash step is not considered essential and
is optional.
[0067] The washed steam exploded stream comprising the washed
exploded biomass is labeled 7. The washed exploded stream is then
processed to remove at least a portion of the liquid in the washed
exploded material. This separation step is also optional. The term
at least a portion is removed, is to remind one that while removal
of as much liquid as possible is desirable (pressing), it is
unlikely that 100% removal is possible. In any event, 100% removal
of the water is not desirable since water is needed for the
subsequent hydrolysis reaction. The preferred process for this step
is again a press, but other known techniques and those not invented
yet are believed to be suitable. The solids separated from this
process are in the second solid stream 10. Stream 9 is noted and is
the second liquid stream.
[0068] The embodiment in FIG. 7 shows the process without the
optional washing and separation of the liquid from the steam
exploded material.
[0069] The liquid of the first liquid stream is then combined with
the solids of the second solid stream to form stream 20.
[0070] The product of this process is noted as very specific, in
that one or any combination of the following improvements are
achieved:
[0071] A) the levels of inhibitors and undesirable products to the
next steps (e.g. enzymatic hydrolysis, fermentation, final product
separation) with the various materials in the biomass are much
lower than other processes;
[0072] B) the global hemicellulose solubilization yield is higher
than other process;
[0073] C) the biomass de-structuring is improved with respect to
other process.
[0074] The novel compositions of this process can be characterized
on the basis of their C5, C6 and furfural amounts. To avoid
dilution effects, the expression of the ratio C5's/C6's and
furfural to the C5's plus C6's, with furfural being present is
sufficient to characterize the new compositions.
[0075] The total C5's in the composition is the sum of arabinan and
xylan in the composition which includes the monomers, dimers,
oligomers and polymers of arabinose and xylose in the liquid and
solid of the composition. The total C6's in the composition is the
glucan content which includes the monomers, dimers, oligomers and
polymers in the liquid and solid.
[0076] As known in the literature, a typical steam exploded biomass
will have a ratio of furfural to [C5's plus C6's].times.10000 of at
least 50, with a ratio of C5's to C6's greater than 0.55. As shown
in the experimental streams from Tables 13 and 14, the process
described herein is capable of producing a steam exploded product
with a furfural content greater than 0, that is always present, but
having a ratio of furfural to (C5's plus C6's).times.10000 of less
than 60. Therefore a composition having a ratio of C5's to C6's in
the range of 0.45 to 0.54, and a ratio of furfural to [C5's plus
C6's].times.10000 between 0 and 60, or more preferably 0 and 50, or
more preferably 0 and 30 is contemplated. It is also noted in
Tables 13 and 14 that the other novel feature is that the product
is low in C5's which also reduces the furfural content.
[0077] As can be seen from the Tables 13 and 14, these compositions
from the steam explosion can be characterized as always having
furfural and having the ratio of C5's to C6's less than 0.45 and a
ratio of furfural to C5's plus C6's.times.10000 of less than 40, or
more preferably, a ratio of C5's to C6's less than 0.45 and a ratio
of furfural to C5's plus C6's.times.10000 of less than 15, or more
preferably the ratio of C5's to C6's less than 0.45 and a ratio of
furfural to C5's plus C6's.times.10000 of less than 10; or more
preferably a ratio of C5's to C6's less than 0.40 and a ratio of
furfural to C5's plus C6's.times.10000 of less than 40, or even
more preferably a ratio of C5's to C6's less than 0.40 and a ratio
of furfural to C5's plus C6's.times.10000 of less than 9, the ratio
of C5's to C6's less than 0.35 and a ratio of furfural to C5's plus
C6's.times.10000 of less than 10, or even more preferably, the
ratio of C5's to C6's less than 0.30 and a ratio of furfural to
C5's plus C6's.times.10000 of less than 7.
[0078] As also shown in Tables 13 and 14, the composition of the
liquid stream is also unique and can be described as always having
furfural and having a ratio of C5's to C6's greater than 4.0 and a
ratio of furfural to C5's plus C6's.times.10000 of less than 80, or
more preferably a ratio of C5's to C6's greater than 4.0 and a
ratio of furfural to C5's plus C6's.times.10000 of less than 60, or
even more preferably a ratio of C5's to C6's greater than 4.0 and a
ratio of furfural to C5's plus C6's.times.10000 of less than 30, or
a broader range of a ratio of C5's to C6's greater than 3.0 and a
ratio of furfural to C5's plus C6's.times.10000 of less than
160.
[0079] Also contemplated is the composition of the liquid stream
always having furfural and having a ratio of C5's to C6's greater
than 1.0 and a ratio of furfural to C5's plus C6's.times.10000 of
less than 800, or more preferably a ratio of C5's to C6's greater
than 1.0 and a ratio of furfural to C5's plus C6's.times.10000 of
less than 700, or even more preferably a ratio of C5's to C6's
greater than 1.0 and a ratio of furfural to C5's plus
C6's.times.10000 of less than 400, or the narrower broad range of a
ratio of C5's to C6's greater than 1.0 and a ratio of furfural to
C5's plus C6's.times.10000 of less than 300.
[0080] A further progression of the process, FIG. 2, is to purify
the first liquid stream to remove even more of the inhibitors such
as the acetic acid, formic acid, levulinic acid, furfural, 5-HMF,
phenolic compounds and, more in general, any undesirable product
which may be formed during previous steps. Some of these compounds
are removable by flashing, which is the preferred method in order
to exploit the temperature and pressure of the stream after
pressing.
[0081] For example, the first liquid stream (temperature:
185.degree. C., saturated liquid phase) was flashed using
conventional conditions to atmospheric pressure. For 100 grams of
the feed stream, having 0.1 grams of furfural, 2 grams of acetic
acid, 0.1 grams of formic acid and 82 grams of water flashed, 0.045
grams of furfural, 0.024 grams of acetic acid, 0.06 grams of formic
acid and 14.7 grams of water were removed. This means that 45% of
furfural, 12% of acetic acid, 6% of formic acid and 17% of the
water were removed without any additional operating costs and
without any loss in sugars.
[0082] Another advantage of flash step is that sugars in the
purified liquid stream 11 are concentrated.
[0083] In the flash process, the pressure from the pressing in the
separation would preferably be preserved until the material is
passed to flash tank and the volatiles removed. The purification of
the first liquid stream can again be done by any other known
techniques (e.g. steam stripping) and likely some which have yet
been invented. This first purified material can be found in the
first purified material stream 11 and then combined with the second
solids stream 10.
[0084] An even further refinement is depicted in FIG. 3, which is
to purify the optional wash effluent, the third liquid stream 8,
into a second purified liquid stream 12, and then combine it with
the second solid stream 10. Due to the nature of the volatiles,
steam stripping using conventional or not conventional methods is
believed to be the preferred approach, even if any other method or
known techniques and likely some which have yet been invented can
be utilized.
[0085] If possible, on the basis of its composition, steam coming
from steam explosion is preferably used to carry out steam
stripping.
[0086] Similarly, referring to FIG. 3, one could purify the second
liquid stream 9, to create a second purified liquid in the second
purified liquid stream 13 and combine it with the material in the
second solid stream 10. Again, given the known attributes, steam
stripping is believed to be the preferred solution.
[0087] Since steam stripping is common, it is believed that a
preferred embodiment of the process steam strip the second and
third liquid streams in the same unit. It is also believed that
steam stripping is also preferred for the first purified liquid
stream, generally after flashing. Therefore another embodiment is
FIG. 4 where the liquid streams are purified in the same unit,
preferably steam stripping to product the purified stream 14 which
is then combined with the second solid stream 10.
[0088] If possible, on the basis of its composition, steam coming
from steam explosion may be used to carry out any steam
stripping.
[0089] For example, in a process as represented in FIG. 2, in which
purification step consists of an atmospheric flash step of the
first liquid stream 5 and a subsequent steam stripping step of the
liquid resulting, performed utilizing all the steam produced by the
steam explosion, it results that 30% of water, 80% of acetic acid,
85% of furfural and 65% of formic acid contained in the first
liquid stream 5 are removed.
[0090] Should further purification be needed depending upon the
feedstock and type of biomass, the purified stream 14, can be
further purified with another process FIG. 5, such as activated
charcoal, activated carbon, molecular sieves or membranes to
produce stream 15. Because the purified stream is expected to have
a large water content, it is believed desirable to concentrate the
hydrolysis reactants and remove the water, therefore a
concentration step is believed helpful for the preferred
embodiment, FIG. 6. The water concentration step can be any one of
the know techniques such as boiling, crystallization, and the like.
During concentration step, there is some removal of volatile
inhibitors. After the concentration step, stream 16 is combined
with the materials in stream 10.
[0091] As shown in the data below, the various steps of this
process have increased the efficiency of hydrolysis reaction.
DISCUSSION
[0092] The superiority of the pretreatment can be seen by comparing
the results presented in the working examples 5-6 compared to
control examples 1, 2, 3, and 4
[0093] The amount of inhibitors generated from xylan fraction in
the pretreatment is considerably lower then those generated in
continuous steam explosion process.
[0094] Using Arundo only 1.3% of xylans present in raw material are
degraded to inhibitors compound (Example 5) with the pretreatment,
while in steam explosion process a 19.3% (Example 1) and 63.8%
(Example 2) are degraded to inhibitors compound.
[0095] A similar behaviour is observed for glucan degradation using
Arundo. Only 0.1% of glucans present in raw material are degraded
to inhibitors compound (Example 5) with the pretreatment, while in
steam explosion process a 1.9% (Example 1) and 4.5% (Example 2) are
degraded to inhibitors compound.
[0096] Using sorghum only 0.97% of xylans present in raw material
are degraded to inhibitors compound (Example 6) with the
pretreatment, while in steam explosion process a 61.7% (Example 3)
and 94.9% (Example 4) are degraded to inhibitors compound.
[0097] A similar behaviour is observed for glucan degradation using
Arundo. Only 0.1% of glucans present in raw material are degraded
to inhibitors compound (Example 6) with the pretreatment, while in
steam explosion process an 8.0% (Example 3) and 9.5% (Example 4)
are degraded to inhibitors compound.
[0098] The overall yield of solubilisation of fermentable sugar
(sum of solubilized xylan and glucans) is another advantage of the
pretreatment.
[0099] An overall yield in terms of fermentable sugar (sum of
solubilized xylan and glucans) of 91.2% is obtained with sorghum
after enzymatic hydrolysis with the pretreatment (Example 5) that
is considerably higher with the values obtained with traditional
steam explosion (65.9% in Example 1, and 69.0% in Example 2).
[0100] An overall yield in terms of fermentable sugar (sum of
solubilized xylan and glucans) of 91.3% is obtained with Arundo
after enzymatic hydrolysis with the pretreatment (Example 6) that
is considerably higher with the values obtained with traditional
steam explosion (56.0% in Example 3, and 50.6% in Example 4)
EXPERIMENTAL SUMMARY
[0101] Arundo and sorghum were submitted to different pretreatment
process. Traditional continuous steam explosion was compared with
the pretreatment consisting of a soaking process and a subsequent
steam explosion process.
[0102] In the pretreatment the liquid fraction generated from the
soaking process is recycled as a unique stream.
[0103] In the soaking process the solubilisation occurs of the
major part of the hemi cellulosic fraction. A low inhibitor amount
is generated in this process due to the milder operational
condition.
[0104] The soaked material is then submitted to a pressing process
in order to remove the liquid fraction (about 62%)
[0105] The solid fraction is then submitted to steam explosion
treatment in which occurs the solubilisation of the remaining
hemicellulose and the de-structuring of cellulose fraction.
[0106] The liquid fraction generated in the soaking process is
submitted to refining process and then recycled to the steam
exploded material.
[0107] The pretreatment lead to less inhibitor in the stream
leaving pretreatment section with consequent lower loss of
fermentable sugar when compared with traditional steam explosion
pretreatment, and increase enzymatic accessibility of the
pretreated material.
[0108] Pretreated material from traditional steam explosion and the
pretreatment were submitted to enzymatic hydrolysis in order to
evaluate the enzymatic accessibility.
[0109] The overall yield of the process was calculated starting
from the composition of raw entering the pretreatment process,
taking into account the material balance of the process and the
enzymatic hydrolysis yield on glucan and xylan.
Example 1
[0110] Arundo has the following composition: 37.5% glucans, 19.3%
xylans, 5.8% acetyl groups, 22.6% Klason lignin 6.3% ash, 8.5%
extractives.
[0111] Arundo was submitted to continuous steam explosion (Stake
Tech reactor) at 200.degree. C. for 6 minutes. This pretreatment
lead to a solubilisation of 70.6% of xylan and 8.6% of glucan. A
19.3% of xylan were degraded to inhibitor compounds (furfural and
other degradation product), and 1.9% of glucans were degraded to
inhibitors compounds (HMF and formic acid)
[0112] An amount of pretreated material which composition can be
summarized in solvent, soluble solid, insoluble solid, is added to
a laboratory fermenter. Solvent (water, buffer, antibacterial
solution) and catalyst solution are added to this material in order
to reach a total solid content of 7.5%. Catalysts solution is
calculated to have an activity of 60 FPU/g glucans and 109 FXU/g
xylan for pretreated Arundo.
[0113] The composition of the stream entering the enzymatic
hydrolysis is shown in Table 1
TABLE-US-00001 TABLE 1 Composition of the stream entering enzymatic
hydrolysis Stream entering Enzymatic hydrolysis (g) Arundo Total
1000.0 Water 925.0 Total solid 75.0 Insoluble solid 55.2 Glucan
25.7 Xylan 4.2 Acetyl group 3.0 Lignin 18.9 Ash 3.3 Extractives 0.0
Soluble solid 19.8 Extractives 6.43 Glucan 0.26 Xylan 0.75 Acetyl
group 2.96 Acetic acid 2.17 5-HMF 0.11 Furfural 0.22 Formic acid
0.00 Glucolygomers as glucan 1.65 Xyloolygomers as xylan 6.74
[0114] After enzymatic hydrolysis, the process liquid and solid
fraction were analyzed in order to quantify the yield of glucan and
xylan solubilisation. In enzymatic hydrolysis process glucan
solubilisation yield was 71%, while xylan solubilisation yield was
84%. The global yield of the process was calculated starting from
the composition of raw entering the pretreatment process, taking
into account the material balance of the process and the enzymatic
hydrolysis yield on glucan and xylan.
[0115] A process solubilisation yield of 69.3% was calculated for
glucan, while a process solubilisation yield of 59.3% was
calculated for xylan. A global solubilisation yield of 65.9%,
referred to the sum of glucan and xylan present in the raw material
is calculated in this process. The global yield for Arundo is in
Table 2
TABLE-US-00002 TABLE 2 Enzymatic hydrolysis and process yield of
glucan and xylan Arundo STEAM EXPLOSION (200.degree. C., 6 min)
Enzymatic hydrolysis yield glucans (%) 71 Enzymatic hydrolysis
yield xylans (%) 84 Glucan Process yield (%) 69.3 Xylan process
yield (%) 59.3 FPU/g.sub.cellulose 60 FPU/g.sub.xylans 220
Example 2
[0116] Arundo has the following composition: 37.5% glucans, 19.3%
xylans, 5.8% acetyl groups, 22.6% Klason lignin 6.3% ash, 8.5%
extractives.
[0117] Arundo was submitted to continuous steam explosion (Stake
Tech reactor) at 215.degree. C. for 6 minutes. This pretreatment
lead to a solubilisation of 90.8% of xylan and 7.1% of glucan. A
63.8% of xylan were degraded to inhibitor compounds (furfural and
other degradation product), and 4.5% of glucans were degraded to
inhibitors compounds (HMF and formic acid)
[0118] An amount of pretreated material which composition can be
summarized in solvent, soluble solid, insoluble solid, is added to
a laboratory fermenter. Solvent (water, buffer, antibacterial
solution) and catalyst solution are added to this material in order
to reach a total solid content of 7.5%. Catalysts solution is
calculated to have an activity of 60 FPU/g glucans and 248 FXU/g
xylan for pretreated Arundo.
[0119] The composition of the stream entering the enzymatic
hydrolysis is shown in Table 3
TABLE-US-00003 TABLE 3 Composition of the stream entering enzymatic
hydrolysis Stream entering Enzymatic hydrolysis (g) Arundo Total
1000.0 Water 925.0 Total solid 75.0 Insoluble solid 53.0 Glucan
26.1 Xylan 1.3 Acetyl group 1.8 Lignin 20.2 Ash 3.6 Extractives 0.0
Soluble solid 22.0 Extractives 6.4 Glucan 0.3 Xylan 0.8 Acetyl
group 1.6 Acetic acid 3.6 5-HMF 0.0 Furfural 0.3 Formic acid 0.1
Glucolygomers as glucan 0.5 Xyloolygomers as xylan 3.6
[0120] After enzymatic hydrolysis, the process liquid and solid
fraction were analyzed in order to quantify the yield of glucan and
xylan solubilisation. In enzymatic hydrolysis process glucan
solubilisation yield was 82%, while xylan solubilisation yield was
99%.
[0121] The global yield of the process was calculated starting from
the composition of raw material entering the pretreatment process,
taking into account the material balance of the process and the
enzymatic hydrolysis yield on glucan and xylan.
[0122] A process solubilisation yield of 87.8% was calculated for
glucan, while a process solubilisation yield of 35% was calculated
for xylan. A global solubilisation yield of 69.0%, referred to the
sum of glucan and xylan present in the raw material is calculated
in this process.
[0123] The global yield for Arundo is in Table 4
TABLE-US-00004 TABLE 4 Enzymatic hydrolysis and process yield of
glucan and xylan Arundo STEAM EXPLOSION (215.degree. C., 6 min)
Enzymatic hydrolysis yield glucans (%) 92 Enzymatic hydrolysis
yield xylans (%) 99 Glucan Process yield (%) 87.8 Xylan process
yield (%) 35.0 FPU/g.sub.cellulose 60 FPU/g.sub.xylans 220
Example 3
[0124] Fiber sorghum has the following composition: 35.8% glucans,
20.0% xylans, 5.61% acetyl groups, 17.3% Klason lignin 6.4% ash,
14.8% extractives.
[0125] Chopped sorghum was submitted to continuous steam explosion
(Stake Tech reactor) at 200.degree. C. for 6 minutes. This
pretreatment lead to a solubilisation of 86.6% of xylan and 25.5%
of glucan. A 61.7% of xylan were degraded to inhibitor compounds
(furfural and other degradation product), and 8.0% of glucans were
degraded to inhibitors compounds (HMF and formic acid)
[0126] An amount of pretreated material which composition can be
summarized in solvent, soluble solid, insoluble solid, is added to
a laboratory fermenter. Solvent (water, buffer, antibacterial
solution) and catalyst solution are added to this material in order
to reach a total solid content of 7.5%. Catalysts solution is
calculated to have an activity of 60 FPU/g glucans and 220 FXU/g
xylan for pretreated Sorghum.
[0127] The composition of the stream entering the enzymatic
hydrolysis is shown in Table 5.
TABLE-US-00005 TABLE 5 Composition of the stream entering enzymatic
hydrolysis Stream entering Enzymatic hydrolysis (g) Sorghum Total
1000.0 Water 925.0 Total solid 75.0 Insoluble solid 42 Glucan 20.0
Xylan 2.0 Acetyl group 0.5 Lignin 17.1 Ash 2.4 Extractives 0.0
Soluble solid 33.0 Extractives 11.1 Glucan 0.1 Xylan 0.5 Acetyl
group 0.2 Acetic acid 1.8 5-HMF 0.1 Furfural 0.2 Formic acid 0.6
Glucolygomers as glucan 4.6 Xyloolygomers as xylan 3.2
[0128] After enzymatic hydrolysis, the process liquid and solid
fraction were analyzed in order to quantify the yield of glucan and
xylan solubilisation. In enzymatic hydrolysis process glucan
solubilisation yield was 77%, while xylan solubilisation yield was
85%.
[0129] The global yield of the process was calculated starting from
the composition of raw material (Table 1) entering the pretreatment
process, taking into account the material balance of the process
and the enzymatic hydrolysis yield on glucan and xylan.
[0130] A process solubilisation yield of 70.8% was calculated for
glucan, while a process solubilisation yield of 32.1% was
calculated for xylan. A global solubilisation yield of 56.0%,
referred to the sum of glucan and xylan present in the raw material
is calculated in this process.
[0131] The global yield for sorghum is in Table 6
TABLE-US-00006 TABLE 6 Enzymatic hydrolysis and process yield of
glucan and xylan Sorghum STEAM EXPLOSION (200.degree. C., 6 min)
Enzymatic hydrolysis yield glucans (%) 77 Enzymatic hydrolysis
yield xylans (%) 85 Glucan Process yield (%) 70.8 Xylan process
yield (%) 32.1 FPU/g.sub.cellulose 60 FPU/g.sub.xylans 220
Example 4
[0132] Fiber sorghum has the following composition: 35.8% glucans,
20.0% xylans, 5.61% acetyl groups, 17.3% Klason lignin 6.4% ash,
14.8% extractives.
[0133] Chopped sorghum was submitted to continuous steam explosion
(Stake Tech reactor) at 207.degree. C. for 6 minutes. This
pretreatment lead to a solubilisation of 94.9% of xylan and 23.4%
of glucan. A 86.3% of xylan were degraded to inhibitor compounds
(furfural and other degradation product), and 9.5% of glucans were
degraded to inhibitors compounds (HMF and formic acid)
[0134] An amount of pretreated material which composition can be
summarized in solvent, soluble solid, insoluble solid, is added to
a laboratory fermenter. Solvent (water, buffer, antibacterial
solution) and catalyst solution are added to this material in order
to reach a total solid content of 7.5%. Catalysts solution is
calculated to have an activity of 60 FPU/g glucans and 248 FXU/g
xylan for pretreated Sorghum.
[0135] The composition of the stream entering the enzymatic
hydrolysis is shown in Table 7.
TABLE-US-00007 TABLE 7 Composition of the stream entering enzymatic
hydrolysis Stream entering Enzymatic hydrolysis (g) Sorghum Total
1000.0 Water 925.0 Total solid 75.0 Insoluble solid 42 Glucan 26.1
Xylan 1.3 Acetyl group 1.8 Lignin 20.2 Ash 3.6 Extractives 0.0
Soluble solid 33.0 Extractives 6.4 Glucan 0.3 Xylan 0.8 Acetyl
group 1.6 Acetic acid 3.6 5-HMF 0.0 Furfural 0.3 Formic acid 0.1
Glucolygomers as glucan 0.5 Xyloolygomers as xylan 3.6
[0136] After enzymatic hydrolysis, the process liquid and solid
fraction were analyzed in order to quantify the yield of glucan and
xylan solubilisation. In enzymatic hydrolysis process glucan
solubilisation yield was 79%, while xylan solubilisation yield was
99%.
[0137] The global yield of the process was calculated starting from
the composition of raw material entering the pretreatment process,
taking into account the material balance of the process and the
enzymatic hydrolysis yield on glucan and xylan.
[0138] A process solubilisation yield of 71.5% was calculated for
glucan, while a process solubilisation yield of 13.4% was
calculated for xylan. A global solubilisation yield of 50.60%,
referred to the sum of glucan and xylan present in the raw material
is calculated in this process.
[0139] The global yield for sorghum is in Table 8.
TABLE-US-00008 TABLE 8 Enzymatic hydrolysis and process yield of
glucan and xylan Sorghum STEAM EXPLOSION (207.degree. C., 6 min)
Enzymatic hydrolysis yield glucans (%) 79 Enzymatic hydrolysis
yield xylans (%) 99 Glucan Process yield (%) 71.5 Xylan process
yield (%) 13.4 FPU/g.sub.cellulose 60 FPU/g.sub.xylans 248
Example 5
[0140] Arundo has the following composition: 37.5% glucans, 19.3%
xylans, 5.8% acetyl groups, 22.6% Klason lignin 6.3% ash, 8.5%
extractives.
[0141] Arundo was submitted to batch soaking process for 100 min at
160.degree. C., in which occurred a first solubilisation of the raw
material. A solid phase and a liquid phase were generated in this
process. The solid phase was submitted to a batch steam explosion
pretreatment at 200.degree. C. for 8 minutes. The liquid phase
generated in the soaking process was then recycled to the steam
exploded material.
[0142] This pretreatment lead to a solubilisation of 81.2% of xylan
and 3.7% of glucan. A 1.3% of xylan were degraded to inhibitor
compounds (furfural and other degradation product), and 0.1% of
glucans were degraded to inhibitors compounds (HMF and formic
acid).
[0143] An amount of pretreated material which composition can be
summarized in solvent, soluble solid, insoluble solid, is added to
a laboratory fermenter. Solvent (water, buffer, antibacterial
solution) and catalyst solution are added to this material in order
to reach a total solid content of 7.5%. Catalysts solution is
calculated to have an activity of 34 FPU/g glucans and 68 FXU/g
xylan for pretreated Arundo.
[0144] The composition of the stream entering enzymatic hydrolysis
is reported in table 9.
TABLE-US-00009 TABLE 9 Composition of the stream entering enzymatic
hydrolysis Stream entering Enzymatic hydrolysis (g) Arundo Total
1000.0 Water 925.0 Total solid 75.0 Insoluble solid 42.7 Glucan
26.7 Xylan 2.5 Galactan 0.4 Arabinan 0.2 Acetyl group 0.8 Lignin
10.8 Ash 1.2 Extractives 0.0 Soluble solid 32.3 Glucan 0.1 Xylan
1.2 Galactan 0.1 Arabinan 0.3 Acetic acid 1.0 HMF 0.0 Furfural 0.1
Glucolygomers as glucan 0.9 Xyloolygomers as xylan 9.4
Galactolygomers as galactan 0.1 Arabinolygomers as arabinan 0.3
Acetyl groups 1.2 Extractives 6.4
[0145] The global yield of the process was calculated starting from
the composition of raw material (Table 1) entering the pretreatment
process, taking into account the material balance of the process
and the enzymatic hydrolysis yield on glucan and xylan
[0146] A process solubilisation yield of 87.4% was calculated for
glucan, while a process solubilisation yield of 97.5% was
calculated for xylan. A global solubilisation yield of 91.2%,
referred to the sum of glucan and xylan present in the raw material
is calculated in this process.
[0147] The global yield for Arundo is in Table 10
TABLE-US-00010 TABLE 10 Enzymatic hydrolysis and process yield of
glucan and xylan Arundo Soak (160.degree. C., 100 min) + Stm Exp
(200.degree. C., 8 min) Enzymatic hydrolysis yield glucans (%) 87.6
Enzymatic hydrolysis yield xylans (%) 98.8 Glucan Process yield (%)
87.4 Xylan Process yield (%) 97.5 FPU/g.sub.cellulose 34
FPU/g.sub.xylans 68
Example 6
[0148] Fiber sorghum has the following composition: 35.8% glucans,
20.0% xylans, 5.61% acetyl groups, 17.3% Klason lignin, 6.4% ash,
14.8% extractives
[0149] Fiber sorghum was submitted to batch soaking process for 25
min at 180.degree. C., in which occurred a first solubilisation of
the raw material. A solid phase and a liquid phase were generated
in this process. The solid phase was submitted to a batch steam
explosion pretreatment at 200.degree. C. for 8 minutes. The liquid
phase generated in the soaking process was then recycled to the
steam exploded material.
[0150] This pretreatment lead to a solubilisation of 63.6% of xylan
and 6.3% of glucan. A 0.97% of xylan were degraded to inhibitor
compounds (furfural and other degradation product), and 0.1% of
glucans were degraded to inhibitors compounds (HMF and formic
acid).
[0151] An amount of pretreated material which composition can be
summarized in solvent, soluble solid, insoluble solid, is added to
a laboratory fermenter. Solvent (water, buffer, antibacterial
solution) and catalyst solution are added to this material in order
to reach a total solid content of 7.5%. Catalysts solution is
calculated to have an activity of 34 FPU/g glucans and 59 FXU/g
xylan for pretreated sorghum.
[0152] The composition of the stream entering enzymatic hydrolysis
is reported in table 11.
TABLE-US-00011 TABLE 11 Composition of the stream entering
enzymatic hydrolysis Stream entering Enzymatic hydrolysis (g)
Sorghum Total 1000.0 Water 925.0 Total solid 75.0 Insoluble solid
42.4 Glucan 25.0 Xylan 5.9 Galactan 0.0 Arabinan 0.4 Acetyl group
1.1 Lignin 8.9 Ash 1.1 Extractives 0.0 Soluble solid 32.6 Glucan
0.1 Xylan 0.3 Galactan 0.0 Arabinan 0.4 Acetic acid 0.9 HMF 0.0
Furfural 0.1 Glucolygomers as glucan 1.3 Xyloolygomers as xylan 7.1
Galactolygomers as galactan 0.3 Arabinolygomers as arabinan 0.5
Acetyl groups 0.8 Extractives 11.1
[0153] The global yield of the process was calculated starting from
the composition of raw material (Table 1) entering the pretreatment
process, taking into account the material balance of the process
and the enzymatic hydrolysis yield on glucan and xylan
[0154] A process solubilisation yield of 87.8% was calculated for
glucan, while a process solubilisation yield of 97.8% was
calculated for xylan. A global solubilisation yield of 91.3%,
referred to the sum of glucan and xylan present in the raw material
is calculated in this process.
[0155] The global yield for Sorghum is in Table 12
TABLE-US-00012 TABLE 12 Enzymatic hydrolysis and process yield of
glucan and xylan Sorghum Soak (180.degree. C., 25 min) + Steam
'Explode (200.degree. C., 8 min) Enzymatic hydrolysis yield glucans
(%) 87.9 Enzymatic hydrolysis yield xylans (%) 98.9 Glucan Process
yield (%) 87.8 Xylan Process yield (%) 97.8 FPU/g.sub.cellulose 34
FPU/g.sub.xylans 59
[0156] Tables 13 and 14 show the stream analysis of the feeds as
they were taken through the various stages of the process as
described in FIG. 1 under the conditions described in the tables
using the equipment in this specification.
TABLE-US-00013 TABLE 13 SORGHUM Control Test1 Test2 Test3 Test4
Test5 Material Sorghum Sorghum Sorghum Sorghum Sorghum Sorghum Soak
(4 from FIG. 1) Time (min) -- 60 100 15 25 25 Temperature (.degree.
C.) -- 160 160 180 180 180 Log(R.sub.0) -- 3.545 3.767 3.532 3.753
3.753 C5 (% wt/wt dry matter basis) 20.0% 20.2% 17.4% 17.6% 17.5%
18.3% C6 (% wt/wt dry matter basis) 35.2% 44.9% 52.0% 43.3% 50.6%
47.5% Furfural (% wt/wt dry matter basis) 0.000% 0.007% 0.005%
0.033% 0.058% 0.021% C5/C6 ratio 0.570 0.450 0.335 0.407 0.346
0.385 Furfural/(C5 + C6) * 10{circumflex over ( )}(4) 0.000 1.092
0.698 5.401 8.487 3.190 Steam explosion (6 from FIG. 1) Time (min)
8 12 8 8 8 Temperature (.degree. C.) 200 200 200 200 200
Log(R.sub.0) 3.847 4.024 3.847 3.847 3.847 C5 (% wt/wt dry matter
basis) 19.9% 16.7% 17.4% 17.2% 18.3% C6 (% wt/wt dry matter basis)
44.8% 52.0% 43.3% 50.6% 47.5% Furfural (% wt/wt dry matter basis)
0.087% 0.060% 0.086% 0.047% 0.256% C5/C6 ratio 0.444 0.321 0.402
0.340 0.386 Furfural/(C5 + C6) * 10{circumflex over ( )}(4) 13.466
8.741 14.119 6.990 38.852 Liquid stream (5 from FIG. 1) C5 (% wt/wt
dry matter basis) 18.0% 24.1% 26.6% 23.2% 20.7% C6 (% wt/wt dry
matter basis) 4.95% 3.56% 6.97% 4.22% 5.72% Furfural (% wt/wt dry
matter basis) 0.069% 0.435% 0.326% 0.365% 0.378% C5/C6 ratio 3.638
6.749 3.825 5.501 3.623 Furfural/(C5 + C6) * 10{circumflex over (
)}(4) 30.091 157.376 97.113 132.866 142.787 Global process (20 from
FIG. 1) C5 (% wt/wt dry matter basis) 19.5% 19.4% 19.5% 19.4% 19.3%
C6 (% wt/wt dry matter basis) 35.2% 35.2% 35.2% 35.2% 35.1%
Furfural (% wt/wt dry matter basis) 0.083% 0.190% 0.140% 0.153%
0.292% C5/C6 ratio 0.553 0.552 0.554 0.552 0.548 Furfural/(C5 + C6)
* 10{circumflex over ( )}(4) 15.164 34.860 25.584 28.035 53.632
TABLE-US-00014 TABLE 14 ARUNDO Control Test1 Test2 Test3 Test4
Test5 Material Arundo Arundo Arundo Arundo Arundo Arundo Soak (4
from FIG. 1) Time (min) -- 100 100 60 25 15 Temperature (.degree.
C.) -- 160 160 160 180 180 Log(R.sub.0) -- 3.767 3.767 3.545 3.753
3.532 C5 (% wt/wt dry matter basis) 19.3% 18.4% 18.4% 19.0% 15.5%
16.1% C6 (% wt/wt dry matter basis) 37.0% 47.3% 47.3% 45.0% 51.7%
49.3% Furfural (% wt/wt dry matter basis) 0.000% 0.015% 0.015%
0.005% 0.015% 0.014% C5/C6 ratio 0.521 0.390 0.390 0.421 0.300
0.326 Furfural/(C5 + C6) * 10{circumflex over ( )}(4) 0.000 2.324
2.324 0.807 2.221 2.140 Steam explosion (6 from FIG. 1) Time (min)
8 12 8 8 8 Temperature (.degree. C.) 200 200 200 200 200
Log(R.sub.0) 3.847 4.024 3.847 3.847 3.847 C5 (% wt/wt dry matter
basis) 18.0% 17.9% 18.8% 15.4% 15.9% C6 (% wt/wt dry matter basis)
47.2% 47.2% 45.0% 51.7% 49.3% Furfural (% wt/wt dry matter basis)
0.182% 0.173% 0.056% 0.045% 0.027% C5/C6 ratio 0.380 0.379 0.417
0.298 0.323 Furfural/(C5 + C6) * 10{circumflex over ( )}(4) 27.980
26.625 8.855 6.751 4.145 Liquid stream (5 from FIG. 1) C5 (% wt/wt
dry matter basis) 20.5% 20.5% 18.9% 26.4% 26.7% C6 (% wt/wt dry
matter basis) 2.43% 2.43% 3.95% 3.23% 4.91% Furfural (% wt/wt dry
matter basis) 0.120% 0.120% 0.067% 0.174% 0.248% C5/C6 ratio 8.441
8.441 4.773 8.177 5.426 Furfural/(C5 + C6) * 10{circumflex over (
)}(4) 52.203 52.203 29.411 58.721 78.382 Global process (20 from
FIG. 1) C5 (% wt/wt dry matter basis) 18.5% 18.5% 18.8% 18.7% 18.9%
C6 (% wt/wt dry matter basis) 37.0% 37.0% 37.0% 36.9% 36.9%
Furfural (% wt/wt dry matter basis) 0.168% 0.161% 0.059% 0.084%
0.089% C5/C6 ratio 0.502 0.501 0.508 0.507 0.513 Furfural/(C5 + C6)
* 10{circumflex over ( )}(4) 30.276 29.051 10.496 15.162 15.853
[0157] The following two series of experiments, 15 and 16 were
carried out on a continuous process on wheat straw and arundo
respectively. There are some composition with no furfural and this
is believed to be caused by an excessive amount of steam keeping
the furfural in the vapour stream after steam explosion.
TABLE-US-00015 TABLE 15A Wheat Straw Control Test1 Test2 Test3
Test4 Test5 Wheat Wheat Wheat Wheat Wheat Wheat MATERIAL Straw
Straw Straw Straw Straw Straw Soaking Temperature (.degree. C.) --
155 165 165 165 165 Time (min) -- 97 67 67 67 67 Log(R.sub.0) --
3.61 3.74 3.74 3.74 3.74 Steam explosion Temperature (.degree. C.)
-- 195 195 200 205 195 Time (min) -- 4 4 4 4 4 Log(R.sub.0) -- 3.40
3.40 3.55 3.69 3.40 C5 (% wt/wt dry matter basis) 21.6% 11.2% 10.0%
8.6% 6.9% 9.1% C6 (% wt/wt dry matter basis) 34.9% 45.3% 44.2%
49.2% 48.9% 44.9% Furfural (% wt/wt dry matter basis) 0.00% 0.00%
0.00% 0.00% 0.00% 0.00% C5/C6 ratio 0.62 0.25 0.23 0.18 0.14 0.20
Furfural/(C5 + C6) * 10.sup.4 0.00 0.00 0.00 0.00 0.00 0.00 Liquid
stream C5 (% wt/wt dry matter basis) -- 32.9% 39.6% 39.6% 39.6%
21.5% C6 (% wt/wt dry matter basis) -- 11.6% 14.9% 14.9% 14.9%
14.8% Furfural (% wt/wt dry matter basis) -- 0.90% 0.83% 0.83%
0.83% 2.95% C5/C6 ratio -- 2.85 2.66 2.66 2.66 1.45 Furfural/(C5 +
C6) * 10.sup.4 -- 202.42 151.76 151.76 151.76 810.50 Global process
C5 (% wt/wt dry matter basis) 21.6% 14.7% 14.0% 13.0% 11.7% 10.2%
C6 (% wt/wt dry matter basis) 34.9% 39.8% 40.3% 44.4% 43.9% 42.3%
Furfural (% wt/wt dry matter basis) 0.00% 0.15% 0.11% 0.12% 0.12%
0.25% C5/C6 ratio 0.62 0.37 0.35 0.29 0.27 0.24 Furfural/(C5 + C6)
* 10.sup.4 0.00 27.07 20.49 20.18 21.70 48.02
TABLE-US-00016 TABLE 15B Wheat Straw Test6 Test7 Test8 Test9 Test10
Test11 Wheat Wheat Wheat Wheat Wheat Wheat MATERIAL Straw Straw
Straw Straw Straw Straw Soaking Temperature (.degree. C.) 165 165
165 165 165 165 Time (min) 67 67 51 51 51 37 Log(R0) 3.74 3.74 3.62
3.62 3.62 3.48 Steam explosion Temperature (.degree. C.) 200 205
195 200 205 195 Time (min) 4 4 4 4 4 4 Log(R0) 3.55 3.69 3.40 3.55
3.69 3.40 C5 (% wt/wt dry matter basis) 5.8% 4.9% 8.5% 6.0% 4.7%
14.5% C6 (% wt/wt dry matter basis) 44.1% 44.9% 44.9% 43.9% 40.9%
49.6% Furfural (% wt/wt dry matter basis) 0.05% 0.06% 0.04% 0.06%
0.06% 0.00% C5/C6 ratio 0.13 0.11 0.19 0.14 0.12 0.29 Furfural/(C5
+ C6) * 10.sup.4 10.88 12.10 7.98 11.58 13.62 0.00 Liquid stream C5
(% wt/wt dry matter basis) 21.5% 21.5% 19.7% 19.7% 19.7% 26.6% C6
(% wt/wt dry matter basis) 14.8% 14.8% 14.4% 14.4% 14.4% 14.7%
Furfural (% wt/wt dry matter basis) 2.95% 2.95% 2.32% 2.32% 2.32%
2.95% C5/C6 ratio 1.45 1.45 1.37 1.37 1.37 1.81 Furfural/(C5 + C6)
* 10.sup.4 810.50 810.50 681.43 681.43 681.43 713.38 Global process
C5 (% wt/wt dry matter basis) 7.2% 6.4% 9.5% 7.2% 6.1% 15.2% C6 (%
wt/wt dry matter basis) 41.6% 42.4% 42.1% 41.2% 38.5% 47.6%
Furfural (% wt/wt dry matter basis) 0.30% 0.31% 0.25% 0.26% 0.27%
0.17% C5/C6 ratio 0.17 0.15 0.23 0.18 0.16 0.32 Furfural/(C5 + C6)
* 10.sup.4 61.89 63.08 48.54 54.54 60.22 27.69
TABLE-US-00017 TABLE 15C Wheat Straw Test12 Test13 Test14 Test15
Test16 Test17 Wheat Wheat Wheat Wheat Wheat Wheat MATERIAL Straw
Straw Straw Straw Straw Straw Soaking Temperature (.degree. C.) 165
165 165 165 165 170 Time (min) 37 37 27 27 27 37 Log(R.sub.0) 3.48
3.48 3.35 3.35 3.35 3.63 Steam explosion Temperature (.degree. C.)
200 205 195 200 205 195 Time (min) 4 4 4 4 4 4 Log(R.sub.0) 3.55
3.69 3.40 3.55 3.69 3.40 C5 (% wt/wt dry matter basis) 7.6% 4.9%
14.0% 8.0% 5.7% 8.2% C6 (% wt/wt dry matter basis) 50.6% 47.9%
49.9% 49.8% 48.2% 53.5% Furfural (% wt/wt dry matter basis) 0.02%
0.03% 0.00% 0.00% 0.03% 0.00% C5/C6 ratio 0.15 0.10 0.28 0.16 0.12
0.15 Furfural/(C5 + C6) * 10.sup.4 3.96 4.85 0.00 0.00 5.71 0.00
Liquid stream C5 (% wt/wt dry matter basis) 26.6% 26.6% 29.8% 29.8%
29.8% 27.3% C6 (% wt/wt dry matter basis) 14.7% 14.7% 16.4% 16.4%
16.4% 13.5% Furfural (% wt/wt dry matter basis) 2.95% 2.95% 1.99%
1.99% 1.99% 1.70% C5/C6 ratio 1.81 1.81 1.81 1.81 1.81 2.03
Furfural/(C5 + C6) * 10.sup.4 713.38 713.38 430.07 430.07 430.07
417.42 Global process C5 (% wt/wt dry matter basis) 8.7% 6.2% 15.1%
9.5% 7.5% 9.9% C6 (% wt/wt dry matter basis) 48.5% 46.0% 47.6%
47.4% 45.8% 49.9% Furfural (% wt/wt dry matter basis) 0.20% 0.20%
0.14% 0.14% 0.18% 0.15% C5/C6 ratio 0.18 0.13 0.32 0.20 0.16 0.20
Furfural/(C5 + C6) * 10.sup.4 34.20 37.95 21.90 25.26 33.63
25.38
TABLE-US-00018 TABLE 15D Wheat Straw Test18 Test19 Test20 Test21
Test22 Test23 Wheat Wheat Wheat Wheat Wheat Wheat MATERIAL Straw
Straw Straw Straw Straw Straw Soaking Temperature (.degree. C.) 170
170 155 155 155 155 Time (min) 37 37 72 72 72 72 Log(R.sub.0) 3.63
3.63 3.48 3.48 3.48 3.48 Steam explosion Temperature (.degree. C.)
200 205 195 200 195 195 Time (min) 4 4 4 4 4 4 Log(R.sub.0) 3.55
3.69 3.40 3.55 3.40 3.40 C5 (% wt/wt dry matter basis) 5.6% 4.9%
14.3% 10.4% 18.7% 17.0% C6 (% wt/wt dry matter basis) 48.8% 48.8%
49.4% 46.7% 43.6% 44.7% Furfural (% wt/wt dry matter basis) 0.02%
0.02% 0.00% 0.00% 0.00% 0.00% C5/C6 ratio 0.12 0.10 0.29 0.22 0.43
0.38 Furfural/(C5 + C6) * 10.sup.4 4.46 4.39 0.00 0.00 0.00 0.00
Liquid stream C5 (% wt/wt dry matter basis) 27.3% 27.3% 22.7% 22.7%
29.3% 31.7% C6 (% wt/wt dry matter basis) 13.5% 13.5% 12.3% 12.3%
14.3% 14.3% Furfural (% wt/wt dry matter basis) 1.70% 1.70% 2.01%
2.01% 1.61% 1.96% C5/C6 ratio 2.03 2.03 1.85 1.85 2.05 2.22
Furfural/(C5 + C6) * 10.sup.4 417.42 417.42 574.97 574.97 369.56
427.34 Global process C5 (% wt/wt dry matter basis) 7.6% 6.9% 15.2%
11.7% 19.3% 18.6% C6 (% wt/wt dry matter basis) 45.7% 45.7% 45.4%
43.1% 41.9% 41.4% Furfural (% wt/wt dry matter basis) 0.17% 0.17%
0.21% 0.21% 0.10% 0.21% C5/C6 ratio 0.17 0.15 0.33 0.27 0.46 0.45
Furfural/(C5 + C6) * 10.sup.4 32.67 32.95 35.37 39.14 15.65
35.64
TABLE-US-00019 TABLE 15E Wheat Straw Test24 Test25 Test26 Wheat
Wheat Wheat MATERIAL Straw Straw Straw Soaking Temperature
(.degree. C.) 155 155 155 Time (min) 132 132 132 Log(R.sub.0) 3.74
3.74 3.74 Steam explosion Temperature (.degree. C.) 190 195 200
Time (min) 4 4 4 Log(R.sub.0) 3.25 3.40 3.55 C5 (% wt/wt dry matter
basis) 14.0% 11.2% 10.8% C6 (% wt/wt dry matter basis) 45.7% 45.6%
45.8% Furfural (% wt/wt dry matter basis) 0.00% 0.00% 0.00% C5/C6
ratio 0.31 0.25 0.24 Furfural/(C5 + C6) * 10.sup.4 0.00 0.00 0.00
Liquid stream C5 (% wt/wt dry matter basis) 27.8% 27.8% 27.8% C6 (%
wt/wt dry matter basis) 12.4% 12.4% 12.4% Furfural (% wt/wt dry
matter basis) 2.62% 2.62% 2.62% C5/C6 ratio 2.24 2.24 2.24
Furfural/(C5 + C6) * 10.sup.4 651.91 651.91 651.91 Global process
C5 (% wt/wt dry matter basis) 15.6% 13.1% 12.7% C6 (% wt/wt dry
matter basis) 42.0% 41.9% 42.1% Furfural (% wt/wt dry matter basis)
0.30% 0.30% 0.30% C5/C6 ratio 0.37 0.31 0.30 Furfural/(C5 + C6) *
10.sup.4 51.30 53.70 53.88
TABLE-US-00020 TABLE 16A Arundo Control Test1 Test2 Test3 Test4
Test5 MATERIAL Arundo Arundo Arundo Arundo Arundo Arundo Soaking
Temperature (.degree. C.) -- 52 127 127 127 52 Time (min) -- 165
155 155 155 175 Log(R.sub.0) -- 3.630 3.723 3.723 3.723 3.924 Steam
explosion Temperature (.degree. C.) -- 6 6 4 6 6 Time (min) -- 195
200 195 195 195 Log(R.sub.0) -- 3.575 3.723 3.399 3.575 3.575 C5 (%
wt/wt dry matter basis) 20.0% 12.1% 10.4% 11.0% 14.0% 6.8% C6 (%
wt/wt dry matter basis) 33.7% 42.5% 49.0% 53.5% 45.8% 51.6%
Furfural (% wt/wt dry matter basis) 0.0% 0.0% 0.1% 0.0% 0.0% 0.0%
C5/C6 ratio 0.521 0.28 0.21 0.20 0.31 0.13 Furfural/(C5 + C6) *
10.sup.4 0.000 0.00 14.66 3.51 7.08 3.51 Liquid stream C5 (% wt/wt
dry matter basis) -- 20.9% 32.2% 29.1% 22.9% 25.7% C6 (% wt/wt dry
matter basis) -- 12.13% 18.66% 16.46% 20.60% 11.10% Furfural (%
wt/wt dry matter basis) -- 0.953% 1.589% 1.706% 0.737% 2.915% C5/C6
ratio -- 1.720 1.724 1.769 1.113 2.314 Furfural/(C5 + C6) *
10.sup.4 -- 288.973 312.769 374.226 169.278 792.653 Global process
C5 (% wt/wt dry matter basis) -- 13.2% 14.6% 15.6% 16.2% 11.8% C6
(% wt/wt dry matter basis) -- 38.5% 43.2% 44.0% 39.6% 40.8%
Furfural (% wt/wt dry matter basis) -- 0.126% 0.375% 0.455% 0.213%
0.793% C5/C6 ratio -- 0.344 0.338 0.355 0.409 0.290 Furfural/(C5 +
C6) * 10.sup.4 -- 24.337 64.984 76.369 38.271 150.873
TABLE-US-00021 TABLE 16B Arundo Test6 Test7 Test8 Test9 Test10
Test11 MATERIAL Arundo Arundo Arundo Arundo Arundo Arundo Soaking
Temperature (.degree. C.) 52 52 52 52 52 52 Time (min) 175 175 175
175 175 175 Log(R.sub.0) 3.924 3.924 3.924 3.924 3.924 3.924 Steam
explosion Temperature (.degree. C.) 2 2 6 2 2 6 Time (min) 195 210
195 195 205 205 Log(R.sub.0) 3.098 3.540 3.575 3.098 3.393 3.870 C5
(% wt/wt dry matter basis) 6.8% 4.3% 5.0% 6.0% 5.0% 4.4% C6 (%
wt/wt dry matter basis) 52.6% 47.8% 47.5% 48.8% 47.5% 50.2%
Furfural (% wt/wt dry matter basis) 0.0% 0.0% 0.0% 0.0% 0.0% 0.0%
C5/C6 ratio 0.13 0.09 0.10 0.12 0.10 0.09 Furfural/(C5 + C6) *
10.sup.4 3.60 3.82 5.08 3.26 5.08 4.34 Liquid stream C5 (% wt/wt
dry matter basis) 25.7% 25.7% 24.0% 24.0% 24.0% 24.0% C6 (% wt/wt
dry matter basis) 11.10% 11.10% 13.08% 13.08% 13.08% 13.08%
Furfural (% wt/wt dry matter basis) 2.915% 2.915% 2.328% 2.328%
2.328% 2.328% C5/C6 ratio 2.314 2.314 1.835 1.835 1.835 1.835
Furfural/(C5 + C6) * 10.sup.4 792.653 792.653 627.740 627.740
627.740 627.740 Global process C5 (% wt/wt dry matter basis) 11.7%
10.8% 10.6% 11.3% 10.6% 10.5% C6 (% wt/wt dry matter basis) 41.9%
36.7% 37.4% 38.3% 37.4% 38.6% Furfural (% wt/wt dry matter basis)
0.768% 0.894% 0.703% 0.696% 0.703% 0.744% C5/C6 ratio 0.280 0.294
0.283 0.295 0.283 0.272 Furfural/(C5 + C6) * 10.sup.4 143.325
188.168 146.649 140.422 146.649 151.571
TABLE-US-00022 TABLE 16C Arundo Test12 Test13 Test14 Test15 Test16
Test17 MATERIAL Arundo Arundo Arundo Arundo Arundo Arundo Soaking
Temperature (.degree. C.) 127 127 127 97 97 187 Time (min) 155 155
155 165 165 155 Log(R.sub.0) 3.723 3.723 3.723 3.901 3.901 3.891
Steam explosion Temperature (.degree. C.) 6 2 2 6 2 6 Time (min)
195 195 213 195 195 195 Log(R.sub.0) 3.575 3.098 3.628 3.575 3.098
3.575 C5 (% wt/wt dry matter basis) 12.3% 13.2% 10.1% 11.4% 13.6%
14.1% C6 (% wt/wt dry matter basis) 42.1% 36.2% 48.2% 45.4% 46.9%
45.2% Furfural (% wt/wt dry matter basis) 0.0% 0.0% 0.1% 0.0% 0.0%
0.0% C5/C6 ratio 0.29 0.37 0.21 0.25 0.29 0.31 Furfural/(C5 + C6) *
10.sup.4 4.56 2.30 11.54 2.07 1.65 2.10 Liquid stream C5 (% wt/wt
dry matter basis) 24.0% 24.0% 24.0% 24.8% 24.8% 26.2% C6 (% wt/wt
dry matter basis) 15.73% 15.73% 15.73% 11.47% 11.47% 14.90%
Furfural (% wt/wt dry matter basis) 1.178% 1.178% 1.178% 1.372%
1.372% 1.501% C5/C6 ratio 1.527 1.527 1.527 2.166 2.166 1.759
Furfural/(C5 + C6) * 10.sup.4 296.352 296.352 296.352 377.872
377.872 365.159 Global process C5 (% wt/wt dry matter basis) 14.9%
15.4% 13.5% 14.1% 15.9% 16.8% C6 (% wt/wt dry matter basis) 36.2%
32.2% 40.2% 38.6% 39.7% 38.4% Furfural (% wt/wt dry matter basis)
0.283% 0.244% 0.341% 0.284% 0.287% 0.344% C5/C6 ratio 0.413 0.479
0.336 0.364 0.400 0.438 Furfural/(C5 + C6) * 10.sup.4 55.330 51.220
63.585 53.986 51.659 62.326
TABLE-US-00023 TABLE 16D Arundo Test18 Test19 Test20 Test21 Test22
MATERIAL Arundo Arundo Arundo Arundo Arundo Soaking Temperature
(.degree. C.) 187 67 67 65 65 Time (min) 155 165 165 165 165
Log(R.sub.0) 3.891 3.740 3.740 3.727 3.727 Steam explosion
Temperature (.degree. C.) 2 6 2 4 4 Time (min) 195 195 195 195 205
Log(R.sub.0) 3.098 3.575 3.098 3.399 3.694 C5 (% wt/wt dry matter
basis) 14.8% 11.4% 13.1% 15.91% 10.80% C6 (% wt/wt dry matter
basis) 43.5% 44.9% 46.5% 44.74% 49.06% Furfural (% wt/wt dry matter
basis) 0.0% 0.0% 0.0% 0.04% 0.08% C5/C6 ratio 0.34 0.26 0.28 0.36
0.22 Furfural/(C5 + C6) * 10.sup.4 2.08 4.52 2.21 6.07 12.76 Liquid
stream C5 (% wt/wt dry matter basis) 26.2% 20.3% 20.3% 24.8% 24.8%
C6 (% wt/wt dry matter basis) 14.90% 10.91% 10.91% 10.64% 10.64%
Furfural (% wt/wt dry matter basis) 1.501% 0.958% 0.958% 2.187%
2.187% C5/C6 ratio 1.759 1.862 1.862 2.335 2.335 Furfural/(C5 + C6)
* 10.sup.4 365.159 306.865 306.865 616.267 616.267 Global process
C5 (% wt/wt dry matter basis) 17.3% 13.4% 14.7% 17.9% 14.1% C6 (%
wt/wt dry matter basis) 37.4% 37.1% 38.3% 37.2% 40.0% Furfural (%
wt/wt dry matter basis) 0.331% 0.238% 0.232% 0.511% 0.576% C5/C6
ratio 0.462 0.362 0.385 0.480 0.353 Furfural/(C5 + C6) * 10.sup.4
60.614 47.022 43.701 92.755 106.421
[0158] Enzymatic Hydrolysis Procedure
[0159] This procedure is used to measure the efficacy of a given
pretreatment based on a maximum enzyme loading.
[0160] This procedure describes the enzymatic saccharification of
cellulose and hemicellulose from native or pretreated
lignocellulosic biomass to glucose and xylose in order to determine
the maximum extent of digestibility possible (a saturating level of
a commercially available or in house produced cellulase preparation
and hydrolysis times up to one week are used).
[0161] Pretreated biomass--Biomass that has been subjected to
milling, chemical treatment with water or steam, strong or dilute
acid or alkali, or other physical or chemical methods to render the
cellulose content of the material more accessible to enzymatic
action.
[0162] Cellulase enzyme--an enzyme preparation exhibiting all three
synergistic cellulolytic activities: endo-1,4-.beta.-D-glucanase,
exo-1,4-.beta.-glucosidase, or .beta.-D-glucosidase activities,
which are present to different extents in different cellulase
preparations.
[0163] The pretreated materials were used to enzymatic hydrolysis
(EH) in 3-liter fermenter (Infors HT, Labfors 3). EH was run at
7.5% solids concentration, using commercial enzyme solution. The
temperature and pH were maintained at 45.degree. C. and 5.0,
stirrer was maintained at 400 rpm.
[0164] An amount of pretreated material which composition can be
summarized in solvent, soluble solid, insoluble solid, is added to
a laboratory fermenter. Solvent (water, buffer, antibacterial
solution) and catalyst solution are added to this material in order
to reach a total solid content of 7.5%. Catalysts solution is
calculated to have an activity expressed in FPU/g cellulose of
34.
[0165] Catalyst composition is shown in the following table:
TABLE-US-00024 TABLE 15 Enzyme cocktail vol comp Density Name %
g/ml specific activity cellulase complex 87.4% 1.08 100 FPU/g
enzyme solution 1 xylanase 5.3% 1.2 500 FBG/g enzyme solution 1
hemicellulase 6.6% 1.1 470 FXU/g enzyme solution 1 enzyme complex
0.7% 1.2 100 FBG/g enzyme solution 1 Total 100.0% 1.09
[0166] pH is maintained at the desiderate value by the addition of
buffer solution or through base or acid solutions.
[0167] An aliquot of liquid fraction is taken at different time and
analyzed for sugar (glucose, xylose and cellobiose) content. The
solid phase at the end of the reaction is recovered. An aliquot of
the solid phase is washed three times in 3 time volume of water at
50.degree. C. During washing all the soluble fraction adsorbed on
the solid is eliminated. Washed solid is then subjected to moisture
and quantitative acid hydrolysis with 72% H.sub.2SO.sub.4 following
standard methods (NREL) to quantify its composition.
[0168] Reagents
[0169] 7.1 Reagents
[0170] Sodium Azide (20 mg/ml in distilled water)
[0171] Cellulase enzyme complex of known activity, FPU/mL.
[0172] Xylanase enzyme of known of known activity, FXU/mL
[0173] Analytical Determination
[0174] Raw material was subjected to moisture and extractives
determination and to quantitative acid hydrolysis with 72%
H.sub.2SO.sub.4 following standard methods (NREL/TP-510-42618,
NREL/TP-510-42619, NREL/TP-510-42622) The solid residue after
hydrolysis was recovered by filtration and considered as Klason
lignin. Hydrolyzates were analyzed for monosaccharides (glucose
coming from cellulose; xylose and arabinose coming from
hemicelluloses) and acetic acid (coming from acetyl groups) by
HPLC. Chromatographic determination was performed using a Dionex
P680A_LPG equipped with an ion exchange resin Biorad Aminex HPX-87A
column under the following conditions: mobile phase, 0.05 mol/L of
sulphuric acid; flow rate, 0.6 ml/min; and column temperature,
65.degree. C.
[0175] Moisture content of the samples was determined by
oven-drying at 105.degree. C. to constant weight.
[0176] After pre-treatment, solid residues were recovered by
filtration, washed with water, air-dried, and weighted for yield
determination. Aliquots of the solid residues from pretreatment
were assayed for composition using the same methods as for raw
material analysis applied on the washed solid fraction of the
stream.
[0177] Insoluble solid content of the samples was determined by
following standard method (NREL/TP-510-42627).
[0178] An aliquot of the liquid phase out of the soaking and the
liquid phase accompanying the steam explosion material was
oven-dried to a constant weight to determine the content in
non-volatile solids (NREL/TP-510-42621)
[0179] Liquors were used for direct HPLC determination of
monosaccharides, furfural hydroxymethylfurfural and acetic acid. An
aliquot of liquors was subjected to quantitative acid hydrolysis
with 4% (w/w) H.sub.2SO.sub.4 at 121.degree. C. for 60 min, before
HPLC analysis (NREL/TP-510-42623). Gluco, arabino,
xylo-oligosaccharides concentrations were calculated from the
increases in the concentrations of glucose, xylose and arabinose,
as analyzed by HPLC, after liquor hydrolysis (NREL method)
[0180] NREL Analytical Method
[0181] Determination of Structural Carbohydrates and Lignin in
Biomass
[0182] Laboratory Analytical Procedure (LAP) Issue Date: Apr. 25,
2008
[0183] Technical Report NREL/TP-510-42618 Revised April 2008
[0184] Determination of Extractives in Biomass
* * * * *