U.S. patent application number 14/758909 was filed with the patent office on 2015-12-24 for processing biomass.
The applicant listed for this patent is Xyleco, Inc.. Invention is credited to Thomas Craig MASTERMAN, Marshall MEDOFF.
Application Number | 20150368684 14/758909 |
Document ID | / |
Family ID | 51491991 |
Filed Date | 2015-12-24 |
United States Patent
Application |
20150368684 |
Kind Code |
A1 |
MEDOFF; Marshall ; et
al. |
December 24, 2015 |
PROCESSING BIOMASS
Abstract
Biomass (e.g., plant biomass, animal biomass, and municipal
waste biomass) is processed to produce useful intermediates and
products, such as energy, fuels, foods or materials. Two or more
sugars can be produced and these can be further processed and
purified. For example, a mixture of the two or more sugars can be
selectively fermented to leave one or more sugars in the mixture
along with a product. The unfermented sugar may be fermented with a
different fermenting system and produce a second product.
Inventors: |
MEDOFF; Marshall;
(Brookline, MA) ; MASTERMAN; Thomas Craig;
(Rockport, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Xyleco, Inc. |
Woburn |
MA |
US |
|
|
Family ID: |
51491991 |
Appl. No.: |
14/758909 |
Filed: |
March 7, 2014 |
PCT Filed: |
March 7, 2014 |
PCT NO: |
PCT/US14/21813 |
371 Date: |
July 1, 2015 |
Related U.S. Patent Documents
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Application
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Filing Date |
Patent Number |
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61793336 |
Mar 15, 2013 |
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61774780 |
Mar 8, 2013 |
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61774775 |
Mar 8, 2013 |
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61774773 |
Mar 8, 2013 |
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61774761 |
Mar 8, 2013 |
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61774754 |
Mar 8, 2013 |
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61774752 |
Mar 8, 2013 |
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61774750 |
Mar 8, 2013 |
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61774746 |
Mar 8, 2013 |
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61774744 |
Mar 8, 2013 |
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61774740 |
Mar 8, 2013 |
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61774735 |
Mar 8, 2013 |
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61774731 |
Mar 8, 2013 |
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61774723 |
Mar 8, 2013 |
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61774684 |
Mar 8, 2013 |
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Current U.S.
Class: |
435/99 ; 435/135;
435/136; 435/140; 435/141; 435/147; 435/148; 435/150; 435/157;
435/158; 435/160; 435/165 |
Current CPC
Class: |
C10L 1/023 20130101;
H01J 2237/202 20130101; C12P 7/52 20130101; C10L 9/08 20130101;
B01D 15/02 20130101; B65G 53/40 20130101; Y02P 20/133 20151101;
C12P 7/10 20130101; Y02E 50/10 20130101; Y02W 10/37 20150501; B01D
53/32 20130101; C12M 47/10 20130101; H01J 37/317 20130101; C10L
1/026 20130101; C12P 7/56 20130101; B01J 19/085 20130101; B65G
53/04 20130101; C13K 1/02 20130101; C12P 2201/00 20130101; E04B
1/92 20130101; H01J 2237/3165 20130101; Y02W 10/40 20150501; H01J
2237/31 20130101; B01D 61/44 20130101; Y02E 50/30 20130101; Y02E
60/16 20130101; C07C 29/149 20130101; C10L 2200/0469 20130101; C10L
2290/36 20130101; B01D 61/445 20130101; C12P 19/14 20130101; C13K
13/002 20130101; G21F 7/00 20130101; B01J 2219/0879 20130101; C10G
1/00 20130101; E04B 2001/925 20130101; C12M 47/00 20130101; B01J
2219/0869 20130101; C12P 19/02 20130101; D21C 9/007 20130101; C10L
2200/0476 20130101; C12P 7/06 20130101; C12P 2203/00 20130101; Y02W
10/33 20150501; B01J 2219/0886 20130101; C07C 31/12 20130101; B65G
27/00 20130101; C12P 7/04 20130101; G21K 5/10 20130101; C07C 29/149
20130101; C07C 31/12 20130101 |
International
Class: |
C12P 19/14 20060101
C12P019/14; C12P 7/52 20060101 C12P007/52; C12P 19/02 20060101
C12P019/02; C12P 7/10 20060101 C12P007/10 |
Claims
1. A method of making a product, the method comprising:
saccharifying a reduced recalcitrance cellulosic and/or reduced
recalcitrance lignocellulosic material in a liquid, to form a
mixture comprising two or more sugars, and contacting the
saccharified material with an organism, wherein the organism
selectively ferments a sugar released during saccharification of
the reduced recalcitrance cellulosic or lignocellulosic material to
provide one or more unfermented sugars, fermentation solids and a
first fermentation product.
2. The method of claim 1 further comprising isolating the first
fermentation product from unfermented sugars and fermentation
solids.
3. The method of claim 2 further comprising isolating the first
fermentation product by a method selected from the group consisting
of filtering, centrifuging, evaporation, distillation,
crystallization, precipitation, extraction, chromatography,
electrodialysis, and combinations thereof.
4. The method of claim 3 further comprising distilling the
fermentation product from the one or more unfermented sugars and
fermentation solids.
5. The method of claim 1 further comprising isolating the one or
more unfermented sugars from the fermentation solids.
6. The method of claim 5 further comprising isolating the one or
more unfermented sugars by a method selected from the group
consisting of filtering, centrifuging, evaporation, distillation,
crystallization, precipitation, extraction, chromatography,
electrodialysis, and combinations thereof.
7. The method of claim 1 further comprising utilizing the
fermentation solids as a nutrient source.
8. The method of claim 5 further comprising utilizing the
fermentation solids for a second fermentation.
9. The method of claim 8 wherein the fermentation solids contain
living organisms or remnants of living organisms.
10. The method of claim 5 further comprising converting the one or
more unfermented sugars to another product.
11. The method of claim 5 wherein one of the two or more sugars is
glucose, and wherein the organism selectively ferments glucose.
12. The method of claim 11 wherein a product of the fermentation
comprises an alcohol.
13. The method of claim 11 wherein a product of the fermentation
comprises ethanol.
14. The method of claim 11 wherein the organism comprises a yeast,
or a mixture of organisms.
15. The method of claim 10 wherein the another product is
xylitol.
16. The method of claim 1 wherein the recalcitrance of the biomass
material is reduced by irradiation with ionizing radiation.
17. The method of claim 16 wherein the ionizing radiation comprises
accelerated electrons from an electron beam.
18. The method of claim 16 wherein a total dose of radiation
applied to the cellulose or lignocellulosic material is between
about 10 Mrad and about 200 Mrad.
19. The method of claim 1 further comprising isolating
lignin-derived compounds from the saccharified material prior to
contacting the saccharified material with the fermenting
organism.
20. The method of claim 1 wherein the saccharified material
comprises at least two monosaccharides dissolved in the liquid.
21. The method of claim 20 wherein the monosaccharides comprise at
least 50 wt. % of total carbohydrates available in the reduced
recalcitrance cellulosic or lignocellulosic material.
22. The method of claim 20 wherein the two of the monosaccharides
are glucose and xylose.
23. The method of claim 20 wherein glucose comprises at least 10
wt. % of the monosaccharides present in the saccharified
material.
24. A method of making a first product, the method comprising:
producing a mixture comprising a liquid, a first sugar, a second
sugar, and a saccharified cellulosic or lignocellulosic residue
material produced by saccharification of an irradiated cellulosic
or lignocellulosic material; and fermenting the first sugar to
produce the first product.
25. The method of claim 24 wherein the second sugar is produced at
a concentration of at least about 20 g/L.
26. The method of claim 24 further comprising: filtering the slurry
to provide a filtrate comprising a liquid solution of the second
sugar and the residue.
27. The method of claim 24 further comprising isolating the first
product from the second sugar by distilling the first product.
28. A method of making a second fermentation product, the method
comprising: producing a mixture comprising a liquid, a first sugar,
a second sugar, and a saccharified cellulosic or lignocellulosic
residue material produced by saccharification of an irradiated
cellulosic or lignocellulosic material; and fermenting the first
sugar to produce a first product, isolating the first product
leaving at least a second sugar and fermentation byproducts, and
fermenting the second sugar to produce a second product.
29. The method of claim 28 further comprising isolating the second
product from unfermented sugars and fermentation solids.
30. The method of claim 29 comprising isolating the second product
by a method selected from the group consisting of filtering,
centrifuging, evaporation, distillation, crystallization,
precipitation, extraction, chromatography, electrodialysis, and
combinations thereof.
31. The method of claim 30 wherein the first or second product is
selected from the group consisting of sugars, sugar alcohols,
alcohols, organic acids, unsaturated acids, carboxylic esters,
unsaturated esters, anhydrides, aldehydes, ketones, hydrogen,
carbon dioxide, fuels, biodiesel and combinations thereof.
32. The method of claim 1 wherein the liquid is aqueous.
33. The method of claim 7 wherein the fermentation solids are used
as nutrient source for mammals.
34. The method of claim 4 wherein the fermentation solids are
isolated as distillation bottoms.
35. The method of claim 34 wherein the second fermentation uses
distillation bottoms as a nutrient source for the second
fermentation.
36. The method of claim 31 wherein the product of the fermentation
is an organic acid.
37. The method of claim 36 wherein the product is acetic or butyric
acid.
38. The method of claim 1 wherein saccharifying the reduced
recalcitrance cellulosic and/or reduced recalcitrance
lignocellulosic material comprises using one or more enzymes.
39. The method of claim 1 wherein the organism comprises a yeast,
or a mixture of organisms.
40. The method of claim 18 wherein a total dose of radiation
applied to the cellulose or lignocellulosic material is between
about 15 Mrad and about 75 Mrad.
41. The method of claim 40 wherein a total dose of radiation
applied to the cellulose or lignocellulosic material is between
about 20 Mrad and about 50 Mrad.
42. The method of claim 19 wherein the lignin-derived compounds
comprise soluble lignin-derived compounds.
43. The method of claim 1 wherein the first fermentation product is
selected from the group consisting of sugars, sugar alcohols,
alcohols, organic acids, unsaturated acids, carboxylic esters,
unsaturated esters, anhydrides, aldehydes, ketones, hydrogen,
carbon dioxide, fuels, biodiesel and combinations thereof.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application incorporates by reference the full
disclosure of the following provisional applications: the
provisionals filed Mar. 8, 2013: U.S. Ser. No. 61/774,684; U.S.
Ser. No. 61/774,773; U.S. Ser. No. 61/774,731; U.S. Ser. No.
61/774,735; U.S. Ser. No. 61/774,740; U.S. Ser. No. 61/774,744;
U.S. Ser. No. 61/774,746; U.S. Ser. No. 61/774,750; U.S. Ser. No.
61/774,752; U.S. Ser. No. 61/774,754; U.S. Ser. No. 61/774,775;
U.S. Ser. No. 61/774,780; U.S. Ser. No. 61/774,761; U.S. Ser. No.
61/774,723; and U.S. Ser. No. 61/793,336, filed Mar. 15, 2013.
BACKGROUND OF THE INVENTION
[0002] Many potential lignocellulosic feedstocks are available
today, including agricultural residues, woody biomass, municipal
waste, oilseeds/cakes and seaweed, to name a few. At present, these
materials are often under-utilized, being used, for example, as
animal feed, biocompost materials, burned in a co-generation
facility or even landfilled.
[0003] Lignocellulosic biomass includes crystalline cellulose
fibrils embedded in a hemicellulose matrix, surrounded by lignin.
This produces a compact matrix that is difficult to access by
enzymes and other chemical, biochemical and/or biological
processes. Cellulosic biomass materials (e.g., biomass material
from which the lignin has been removed) is more accessible to
enzymes and other conversion processes, but even so,
naturally-occurring cellulosic materials often have low yields
(relative to theoretical yields) when contacted with hydrolyzing
enzymes. Lignocellulosic biomass is even more recalcitrant to
enzyme attack. Furthermore, each type of lignocellulosic biomass
has its own specific composition of cellulose, hemicellulose and
lignin.
SUMMARY
[0004] Generally, this invention relates to methods and processes
for converting a material, such as a biomass feedstock, e.g.,
cellulosic, starchy or lignocellulosic materials, to useful
products, for example, alcohols (e.g., ethanol and butanol), acids
(e.g. acetic, propionic, butyric, succinic, D- and L-lactic,
pyruvic acid) and sugars (e.g., glucose and xylose). The invention
also relates e.g., to methods equipment and systems for the
separation of products (e.g., purification, isolation or
concentration) from the converted biomass. For example, a mixture
of two or more sugars can be fermented to leave one or more sugars
in the mixture.
[0005] In one aspect the invention relates to a method of making a
product. The method includes saccharifying, such as by using one or
more enzymes, cellulosic or lignocellulosic material, e.g. a
reduced recalcitrance cellulosic or lignocellulosic material, in a
liquid, such as water, to form a mixture comprising two or more
sugars, such as two or more monosaccharides. The method further
includes contacting the saccharified material with an organism,
wherein the organism selectively ferments a sugar released during
the saccharification (e.g., including glucose and/or xylose) to
provide one or more unfermented sugars (e.g., including glucose or
xylose), fermentation solids and a fermentation product.
Optionally, the fermentation product (e.g. an alcohol or an organic
acid) can be isolated from one or more of the unfermented sugars
and fermentation solids, or the fermentation product and one or
more of the unfermented sugars can be isolated from the
fermentation solids, or the fermentation product and fermentation
solids can be isolated from one or more of the unfermented sugars.
Optionally the methods of isolating, e.g., the fermentation
product, includes filtering including ultrafiltration,
centrifuging, evaporation, distillation, crystallization,
precipitation, extraction, chromatography including simulated
moving bed chromatography, electrodialysis including bipolar
electodialysis and combinations of these. Optionally, the methods
also include isolating the one or more unfermented sugars from the
fermentation solids, for example, by filtering, centrifuging,
evaporation, distillation, crystallization, precipitation,
extraction, chromatography and combinations of these (e.g., in any
order). Optionally, the method includes isolating lignin-derived
compounds, such as soluble lignin-derived compounds, from the
saccharified material prior to contacting the saccharified material
with the fermenting organism.
[0006] In some implementations the fermentation solids can be
utilized as a nutrient source, for example as animal feed, for
human consumption or for the growth of organisms (such as bacteria
and yeasts). Optionally, the fermentation solids (e.g., that can
contain living organisms and/or remnants of living organisms), can
be utilized for a second fermentation of a saccharified
lignocellulosic material.
[0007] In some other implementations, the methods further include
converting the one or more unfermented sugars to another product,
such as when the one or more sugars comprise xylose and the other
product comprises xylitol. The fermentation product can comprise an
alcohol (e.g., ethanol). The fermenting organism can include a
yeast, bacteria, fungi, or a mixture of organisms, such as a yeast
and a bacterium.
[0008] In some implementations, the recalcitrance of the biomass
material is reduced by irradiation with ionizing radiation, for
example including accelerated electrons from an electron beam.
Optionally, a total dose of radiation applied to the cellulose or
lignocellulosic material is between about 10 Mrad and about 200
Mrad, such as between about 15 Mrad and about 75 Mrad or between
about 20 Mrad and about 50 Mrad.
[0009] In implementation of the methods wherein the saccharified
material includes two monosaccharides (e.g., glucose and xylose)
dissolved in the liquids, the monosaccharides can include at least
50 wt. % of total carbohydrates available in the reduced
recalcitrance cellulosic or lignocellulosic material, e.g., 60 wt.
%, 70 wt. %, 80 wt. %, 90 wt. %. Optionally, the glucose can
include least 10 wt. % of the monosaccharides present in the
saccharified material, e.g., at least 20 wt. %, 30 wt. %, 40 wt. %,
50 wt. %, 60 wt. %, 70 wt. %, 80 wt. % or 90 wt. %.
[0010] In another aspect, the invention includes a method of making
a product including producing a slurry including a liquid, a first
sugar, a second sugar, and a saccharified cellulosic or
lignocellulosic residue material produced by saccharification of an
irradiated cellulosic or lignocellulosic material, such as by
utilizing one or more enzymes. The method further includes
fermenting the first sugar to produce a product, such as an
alcohol. Optionally, the second sugar is produced at a
concentration of at least about 20 g/L e.g., at least about 30 g/L,
at least about 40 g/L, at least about 50 g/L, at least about 60
g/L, at least about 70 g/L, at least about 80 g/L, at least about
90 g/L, at least about 100 g/L. Optionally, the method further
includes filtering the slurry to provide a filtrate comprising a
liquid solution, such as an aqueous solution, of the second sugar
and the residue. The method can further include isolating the
product, such as an alcohol, from the second sugar by distilling
the product and producing a distillate bottom comprising the second
sugar.
[0011] Saccharified biomass can produce a mixture of products after
saccharification that can be difficult to separate. For example,
mono-saccharides, e.g., glucose and xylose, are often difficult to
separate from each other by conventional means due to their
chemical and physical similarities. For example, in many
chromatography techniques, glucose and xylose elute at similar
times. The selective fermentation of a sugar from a mixture of
sugars can provide a product that is useful. In addition, the
fermented product can have sufficiently different chemical and
physical differences from the unfermented sugars that separation
can be efficiently accomplished. For example, inoculating a
saccharified biomass with an organism that produces D- or L-lactic
acid or their salt from the glucose sugar which results in a slurry
including xylose and lactic acid, which can isolated from each
other in a straightforward manner.
[0012] Other features and advantages of the invention will be
apparent from the following detailed description and from the
claims.
DESCRIPTION OF THE DRAWING
[0013] The foregoing will be apparent from the following more
particular description of example embodiments of the invention, as
illustrated in the accompanying. The drawings are not necessarily
to scale, emphasis instead being placed upon illustrating
embodiments of the present invention.
[0014] FIG. 1 is a diagram illustrating exemplary enzymatic
hydrolysis of biomass.
[0015] FIG. 2 is a flow diagram showing processes for manufacturing
sugar solutions from a feedstock.
[0016] FIG. 3 is a flow diagram showing processes for manufacturing
sugar solutions from a feedstock showing a second fermentation.
[0017] FIG. 4 is a flow diagram that shows conversion of biomass to
xylose.
[0018] FIG. 5 is a flow diagram that shows a purification scheme
for xylose.
[0019] FIG. 6 is a flow diagram that shows a purification scheme
for xylose and an organic acid by two stages of electrodialysis
treatment.
DETAILED DESCRIPTION
[0020] Using the equipment, methods and systems described herein,
cellulosic and lignocellulosic feedstock materials, for example
that can be sourced from biomass (e.g., plant biomass, animal
biomass, paper, and municipal waste biomass) and that are often
readily available but difficult to process, can be turned into
useful products (e.g., sugars such as the mono saccharides xylose
and glucose, and alcohols such as ethanol and butanol). Included
are equipment, methods and systems to selectively remove one of the
biomass-derived sugars from a mixture of sugars by fermenting the
sugar and separating the fermentation product from the rest of the
biomass-derived sugars. The methods and systems are therefore
useful for producing pure or substantially pure (e.g., at least 90,
91, 92, 93, 94 or 95% by weight) biomass-derived products from a
biomass feedstock.
[0021] Biomass is a complex feedstock. For example, lignocellulosic
materials include different combinations of cellulose,
hemicellulose and lignin. Cellulose is a linear polymer of glucose.
Hemicellulose is any of several heteropolymers, such as xylan,
glucuronoxylan, arabinoxylan and xyloglucan. The primary sugar
monomer present (e.g., present in the largest concentration) in
hemicellulose is xylose, although other monomers such as mannose,
galactose, rhamnose, arabinose and glucose are present. Although
all lignins show variation in their composition, they have been
described as an amorphous dendritic network polymer of phenyl
propene units. The amounts of cellulose, hemicellulose and lignin
in a specific biomass material depends on the source of the biomass
material. For example, wood-derived biomass can be about 38-49%
cellulose, 7-26% hemicellulose and 23-34% lignin depending on the
type. Grasses typically are 33-38% cellulose, 24-32% hemicellulose
and 17-22% lignin. Clearly, lignocellulosic biomass constitutes a
large class of substrates.
[0022] Enzymes and biomass-destroying organisms that break down
biomass, such as the cellulose, hemicellulose and/or the lignin
portions of the biomass as described above, contain or manufacture
various cellulolytic enzymes (cellulases), ligninases, xylanases,
hemicellulases or various small molecule biomass-destroying
metabolites. FIG. 1 provides some examples of these
biomass-destroying processes. A cellulosic substrate is initially
hydrolyzed by endoglucanases at random locations producing
oligomeric intermediates. These intermediates are then substrates
for exo-splitting glucanases such as cellobiohydrolase to produce
cellobiose from the ends of the cellulose polymer. Cellobiose is a
water-soluble 1,4-linked dimer of glucose. Finally, cellobiase
cleaves cellobiose to yield glucose. In the case of hemicellulose,
a xylanase (e.g., hemicellulase) acts on this biopolymer and
releases xylose as one of the possible products.
[0023] The enzymes as described above act on biomass in aqueous
solutions, releasing the sugars which can dissolve in the solution.
Due to the complex and diverse sources of the biomass, a varied
mixture of sugars is often produced as a difficult-to-separate
mixture.
[0024] FIG. 2 shows processes for manufacturing sugars and
fermentation products from a feedstock (e.g., cellulosic or
lignocellulosic materials). In an initial step (210) the method
includes optionally mechanically treating a cellulosic and/or
lignocellulosic feedstock. Before and/or after this treatment, the
feedstock can be treated with another physical treatment (212) to
reduce its recalcitrance, for example irradiation, sonication,
steam explosion, oxidation, pyrolysis, various heat treatments,
such as heated water under pressure, or combinations of these, to
reduce or further reduce its recalcitrance. A mixed sugar solution
e.g., including glucose and xylose, is formed by saccharifying the
feedstock (214). The saccharification can be, for example,
accomplished efficiently by the addition of one or more enzymes,
e.g., cellulases and/or xylanases (211). A product or several
products can be derived from the sugar solution, for example, by
fermentation to an alcohol (216). In particular, the product (or
products) can be derived by the fermentation by one or more
organisms that selectively ferment(s) only one sugar in the sugar
solution. Following fermentation, the fermentation product (e.g.,
or products, or a subset of the fermentation products) can be
isolated (224). One optional method of isolating the fermentation
product, for example if the product is an alcohol, is by
distillation. Optionally, after the fermentation product has been
isolated, the materials (e.g., solution, mixture, slurry, solids)
containing the unfermented sugars can be further processed (226),
for example to isolate and/or purify one or more of the unfermented
sugars. If desired, the steps of measuring lignin content (218) and
setting or adjusting process parameters based on this measurement
(220) can be performed at various stages of the process, for
example, as described in U.S. application Ser. No. 12/704,519,
filed on Feb. 11, 2011, the complete disclosure of which is
incorporated herein by reference.
[0025] In some embodiments, it can be desirable to isolate the
unfermented sugars from the solution. For example, one or more
unfermented sugars can be removed from the fermentation product at
step 224. The fermentation product can be subsequently removed from
the solution. For example, the fermentation product can be
distilled and the unfermented sugars remain in the distillate
bottom for optional further processing.
[0026] In some embodiments one or more of the unfermented sugars
can be contacted with an organism or combination of organisms that
ferments the unfermented sugar(s) to a product, e.g., a product
disclosed herein. The unfermented sugar(s) can be fermented prior
to isolation from the fermentation product of the first sugar, for
example, between steps 216 and 224. In one embodiment, the
unfermented sugar(s) can be fermented after isolating the product
of fermenting the first sugar, for example, after step 224. In
another embodiment, the unfermented sugar(s) can be isolated after
isolation of the fermentation product of the first sugar, for
example, after step 224, and then the isolated unfermented sugar
can be fermented with one or more organisms.
[0027] Referring to FIG. 3 after saccharification the mixture is
fermented at step 217 such that only one of the sugars is fermented
to form a first product within a mixture of at least a second
(unfermented) sugar, and fermentation solids. The first product at
step 225 is isolated by any of the isolation technique described
herein. Optionally, the fermentation solids may be separated from
at least the second (unfermented) sugar at step 232. A second
fermentation process at step 227 will convert the second sugar to a
second product which can be isolated by any of the isolation
techniques described herein at step 230. Examples of the first and
second sugar can be glucose and xylose, respectively, with the
glucose being converted in the first fermentation step.
Alternately, the first sugar can be xylose and the second sugar can
be glucose. In this case, the xylose fermentation product is the
first product.
[0028] In an additional embodiment, FIG. 4 shows the steps of
physically treating a biomass (410); treating the feedstock to
reduce recalcitrance (412), mixing in an enzyme (411) and
saccharifying the material to form a mixture that includes sugars,
for example, glucose and xylose (414); inoculating with a
microorganism (428) which selectively converts one sugar e.g. to an
organic acid, while retaining the other sugars (428) leading to
fermentation (416), which leads to a mixture of a retained sugars
and a desired product (424) and then removing the product mixture
(426) to obtain a mixture of sugars and the desired product.
[0029] FIG. 5 shows steps to separate the organic acid from a
sugar, in this case xylose (510). The purification means (520) can
be a simulated moving bed chromatography or other purification
means that can separate sugars from other substrates.
[0030] Pertaining to FIG. 6 two electrodialysis steps are shown as
a purification strategy. To the fermentation product liquid mixture
which has had solids removed from it (610), is added a base if
needed to convert the organic acid to its salt form (620) and
electrodialysis processing is done to separate the nonionic sugars
from the salts (including the organic acid salts). Then the salt is
processed in the bipolar membrane electrodialysis unit (630) in
which the organic acid salt is converted to its neutralized form
and isolated from the salts.
[0031] The selective fermentations as mentioned above can
selectively convert to a fermentation product most or even all of
one of the sugars from available sugars derived from the biomass.
For example, the selective fermentation can remove at least 60%
(e.g., at least 70%, at least 80%, at least 90%, at least 95%, at
least 99%, or even 100%) of one of the sugars, or between 60 and
99% (e.g., between 70 and 99%, between 80 and 99%, between 90 and
99%, between 60 and 70%, between 70 and 80%, between 80 and 90%, or
between 70 and 90%) of one of the sugars. The sugar can be
fermented in stages with different conditions, for example
different nutrients added, different temperatures, different pH
values (e.g., with average values differing by at least 8 units, at
least 5 units, at least 3 units, at least 1 unit), different
concentrations of organism (e.g., differences in cell counts of
more than about 10 fold, more than about 50 fold, more than about
100 fold, more than about 500 fold, more than about 1000 fold),
different agitation rates (e.g., for mixers differences of at least
2 rpm, at least 5 rpm, at least 10 rpm, at least 50 rpm, at least
100 rpm, at least 500 rpm), different oxygenation rates (e.g.,
aerobic, anaerobic) and combinations of these. The organisms can be
in various fermentation stages, for example producing different
products (e.g., hydrogen, carbon dioxide, acids, ketones, alcohols
or combinations thereof). There can be more than one organism
producing the same or different fermentation products. The
organisms can work synergistically, for example, a first organism
can directly ferment the sugar, for example, to produce an acid,
and then another organism can ferment the product of the
fermentation by the first organism, for example, to a hydrocarbon.
In some embodiments, enzymes can be utilized, for example, a
glucose isomerase can be used to isomerize glucose to fructose and
then an organism can be used to remove fructose and/or glucose.
Some relevant uses of isomerase are discussed in PCT Application
No. PCT/US13/71093, filed on Dec. 20, 2012, the entire disclosure
of which is incorporated herein by reference.
[0032] In some embodiments the liquids after saccharification
and/or fermentation can be treated to remove solids, for example,
by centrifugation, filtration, screening, or rotary vacuum
filtration. For example, some methods and equipment that can be
used during or after saccharification are disclosed PCT Application
No. PCT/US13/48963, filed on Jul. 1, 2013, and U.S. Provisional
Application Ser. No. 61/774,684, filed on Mar. 8, 2013, the entire
disclosures of which are incorporated herein by reference. In
addition other separation techniques can be used on the liquids,
for example to remove ions, de-colorize. For example,
chromatography, simulated moving bed chromatograph and
electrodialysis may be especially useful to isolate the products
and the intermediate mixtures. Some of these methods are discussed
in U.S. Provisional Application No. 61/774,775, filed on Mar. 8,
2013 and U.S. Provisional Application No. 61/774,780, filed on Mar.
8, 2013, the entire disclosures of which are incorporated herein by
reference. Solids that are removed during the processing can be
utilized for energy co-generation, for example as discussed in U.S.
Provisional Application No. 61/774,773, filed on Mar. 8, 2013, the
entire disclosure of which is incorporated herein by reference.
[0033] In some cases filtration after fermentation (e.g.,
fermentation of a first sugar, a second sugar or even a third or
fourth sugar derived from the biomass) can provide a nutrient rich
solid (e.g., solid, semi-solid, and filter cake, particulate,
extract) material. For example, the nutrient rich material can
include cellular material from the organism as well as some unused
nutrients added from the fermentations. The nutrient rich material
can be further processed and/or can be sold as a product. In
addition, the nutrient rich material can be used, directly or with
further processing (e.g., sterilization, filtered, washed, diluted,
pH adjusted) in the process, for example, as a nutrient during the
fermentation. In some cases filtration or other means of separation
(e.g., membrane filtration) can recover the fermentation organism
in a viable (e.g., living) form. The recovered fermentation
organism can be used to inoculate subsequent fermentations and/or
sold.
[0034] In some embodiments the carbohydrates in the lignocellulosic
material include at least two different sugars, for example,
glucose and xylose. The sugars can be bound as part of a polymer or
an oligomer. The sugars can also be present as monomers, dimers
and/or trimers). For example, the lignocellulosic material can
include cellulose, starch, hemicellulose, pectin and other
heteropolysaccharides, oligomers of glucose, oligomers of xylose,
dimers and trimers of glucose, dimers and trimers of xylose,
glucose, xylose and combinations of these. The total concentration
of these carbohydrates can be between about 10 wt. % and 90 wt. %
of the dry weight biomass, wherein dry biomass has less than about
5 wt. % water (e.g. the total concentration of sugars is between
about 10 wt. % and 80 wt. %, between about 10 wt. % and 60 wt. %,
between about 10 wt. % and 50 wt. %, between about 10 wt. % and 40
wt. %, between about 20 wt. % and 90 wt. %, between about 20 wt. %
and 80 wt. %, between about 20 wt. % and 70 wt. %, between about 20
wt. % and 60 wt. %, between about 20 wt. % and 50 wt. %, between
about 30 wt. % and 90 wt. %, between about 30 wt. % and 80 wt. %,
between about 30 wt. % and 70 wt. %, between about 30 wt. % and 60
wt. %, between about 30 wt. % and 50 wt. %, between about 40 wt. %
and 90 wt. %, between about 40 wt. % and 80 wt. %, between about 40
wt. % and 70 wt. %, between about 40 wt. % and 60 wt. %, between
about 50 wt. % and 100 wt. %, between about 50 wt. % and 90 wt. %,
between about 50 wt. % and 80 wt. %, between about 50 wt. % and 70
wt. %, between about 60 wt. % and 100 wt. %, between about 60 wt. %
and 90 wt. %, between about 60 wt. % and 80 wt. %, between about 70
wt. % and 90 wt. %,). After saccharification the percent of these
carbohydrates in monomeric form (e.g., not as part of a polymer or
oligomer) can be, for example, at least 50 wt. % of the total
available concentration of the carbohydrates in the dry biomass
prior to saccharification. For example, if the total biomass
comprises 70 wt. % carbohydrates, after saccharification the
monomeric sugars will comprise 35 wt. % of the unsaccharified
biomass (50% of the available 70 wt. % carbohydrates). In some
implementations, after saccharification the percentage of these
carbohydrates that are in monomeric form could be at least 60 wt. %
of the total available concentration of the carbohydrates in the
dry biomass (e.g., at least 70 wt. %, at least 80 wt. %, at least
90 wt. %). After saccharification, glucose (e.g., monomers) can be
present as at least 10 wt. % of the total available concentration
of the carbohydrates in the dry biomass (e.g., at least 10 wt. %,
at least 30 wt. %, at least 40 wt. %, at least 50 wt. %, at least
60 wt. %, at least 70 wt. %, at least 80 wt. %, at least 90 wt. %).
After saccharification, xylose (e.g., monomers) can be present in
at least 5 wt. % of the total available concentration of the
carbohydrates in the dry biomass (e.g., at least 10 wt. %, at least
20 wt. %, at least 30 wt. %, at least 40 wt. %, at least 50 wt. %,
at least 60 wt. %, at least 70 wt. %, at least 80 wt. %, at least
90 wt. %). After saccharification the combined wt. % of the total
available concentration of the carbohydrates in the dry biomass, of
other sugars, for example, arabinose can be less than about 10 wt.
% (e.g., less than 5 wt. %, less than 1 wt. %). After
saccharification one or more of the sugars can be present in a
concentration of at least 10 g/L (e.g., at least 20 g/L, at least
30 g/L, at least 40 g/L, at least 50 g/L, at least 60 g/L, at
least, 70 g/L, at least 80 g/L at least 90 g/L, at least 100 g/L)
without concentrating the solution. The solution can be
concentrated after saccharification to values at least 10% higher
(e.g., at least 20%, at least 30%, at least 50%, at least 100%, at
least 200%, at least 500%, at least 1000%). The solution can even
be concentrated to dryness (e.g., less than about 5 wt. % water).
The solution after saccharification can also be diluted, for
example, by at least 10% (e.g., at least 20%, at least 30%, at
least 50%, at least 100%, at least 200%, at least 500%, at least
1000%).
[0035] After fermentation of the saccharified material a sugar
(e.g., glucose or xylose) can be present in solution at a
concentration of at least 10 g/L (e.g., at least 20 g/L, at least
30 g/L, at least 40 g/L, at least 50 g/L, at least 60 g/L, at
least, 70 g/L, at least 80 g/L at least 90 g/L, at least 100 g/L)
without concentrating the solution. The solution can be
concentrated or diluted similarly to the saccharified material as
previously discussed. The solution can be further processed, for
example, purified and/or converted to other products (e.g., by
hydrogenation) as discussed below.
[0036] In some embodiments the methods can produce a composition
that includes lignin-derived products between about 1 and 30 wt. %,
(e.g., between about 5 and 25%, between about 5 and 20 wt. %), a
fermentation product from a first sugar of between about 5 and 20%
(e.g., between about 10 wt. % and 20 wt. %) and an unfermented
second sugar of between about 1 and 10 wt. %. The composition can
include at least about 40 wt. % water (e.g., 50 wt. % water, 60 wt.
% water, 70 wt. % water, 80 wt. % water). The water can be
evaporated from the composition, producing a material with less
than about 50 wt. % water (e.g. less than about 40 wt. % water,
less than about 30 wt. % water, less than about 20 wt. % water,
less than about 10 wt. % water, less than about 5 wt. % water).
Biomass Materials
[0037] Lignocellulosic materials include, but are not limited to,
wood, particle board, forestry wastes (e.g., sawdust, aspen wood,
wood chips), grasses, (e.g., switchgrass, miscanthus, cord grass,
reed canary grass), grain residues, (e.g., rice hulls, oat hulls,
wheat chaff, barley hulls), agricultural waste (e.g., silage,
canola straw, wheat straw, barley straw, oat straw, rice straw,
jute, hemp, flax, bamboo, sisal, abaca, corn cobs, corn stover,
soybean stover, corn fiber, alfalfa, hay, coconut hair), sugar
processing residues (e.g., bagasse, beet pulp, agave bagasse),
algae, seaweed, manure, sewage, and mixtures of any of these.
[0038] In some cases, the lignocellulosic material includes
corncobs. Ground or hammer milled corncobs can be spread in a layer
of relatively uniform thickness for irradiation, and after
irradiation are easy to disperse in the medium for further
processing. To facilitate harvest and collection, in some cases the
entire corn plant is used, including the corn stalk, corn kernels,
and in some cases even the root system of the plant.
[0039] Advantageously, no additional nutrients (other than a
nitrogen source, e.g., urea or ammonia) are required during
fermentation of corncobs or cellulosic or lignocellulosic materials
containing significant amounts of corncobs.
[0040] Corncobs, before and after comminution, are also easier to
convey and disperse, and have a lesser tendency to form explosive
mixtures in air than other cellulosic or lignocellulosic materials
such as hay and grasses.
[0041] Cellulosic materials include, for example, paper, paper
products, paper waste, paper pulp, pigmented papers, loaded papers,
coated papers, filled papers, magazines, printed matter (e.g.,
books, catalogs, manuals, labels, calendars, greeting cards,
brochures, prospectuses, newsprint), printer paper, polycoated
paper, card stock, cardboard, paperboard, materials having a high
.alpha.-cellulose content such as cotton, and mixtures of any of
these. For example paper products as described in U.S. application
Ser. No. 13/396,365 ("Magazine Feedstocks" by Medoff et al., filed
Feb. 14, 2012), the full disclosure of which is incorporated herein
by reference.
[0042] Cellulosic materials can also include lignocellulosic
materials which have been partially or fully de-lignified.
[0043] In some instances other biomass materials can be utilized,
for example starchy materials. Starchy materials include starch
itself, e.g., corn starch, wheat starch, potato starch or rice
starch, a derivative of starch, or a material that includes starch,
such as an edible food product or a crop. For example, the starchy
material can be arracacha, buckwheat, banana, barley, cassava,
kudzu, oca, sago, sorghum, regular household potatoes, sweet
potato, taro, yams, or one or more beans, such as favas, lentils or
peas. Blends of any two or more starchy materials are also starchy
materials. Mixtures of starchy, cellulosic and or lignocellulosic
materials can also be used. For example, a biomass can be an entire
plant, a part of a plant or different parts of a plant, e.g., a
wheat plant, cotton plant, a corn plant, rice plant or a tree. The
starchy materials can be treated by any of the methods described
herein.
[0044] Microbial materials include, but are not limited to, any
naturally occurring or genetically modified microorganism or
organism that contains or is capable of providing a source of
carbohydrates (e.g., cellulose), for example, protists, e.g.,
animal protists (e.g., protozoa such as flagellates, amoeboids,
ciliates, and sporozoa) and plant protists (e.g., algae such
alveolates, chlorarachniophytes, cryptomonads, euglenids,
glaucophytes, haptophytes, red algae, stramenopiles, and
viridaeplantae). Other examples include seaweed, plankton (e.g.,
macroplankton, mesoplankton, microplankton, nanoplankton,
picoplankton, and femtoplankton), phytoplankton, bacteria (e.g.,
gram positive bacteria, gram negative bacteria, and extremophiles),
yeast and/or mixtures of these. In some instances, microbial
biomass can be obtained from natural sources, e.g., the ocean,
lakes, bodies of water, e.g., salt water or fresh water, or on
land. Alternatively or in addition, microbial biomass can be
obtained from culture systems, e.g., large scale dry and wet
culture and fermentation systems.
[0045] In other embodiments, the biomass materials, such as
cellulosic, starchy and lignocellulosic feedstock materials, can be
obtained from transgenic microorganisms and plants that have been
modified with respect to a wild type variety. Such modifications
may be, for example, through the iterative steps of selection and
breeding to obtain desired traits in a plant. Furthermore, the
plants can have had genetic material removed, modified, silenced
and/or added with respect to the wild type variety. For example,
genetically modified plants can be produced by recombinant DNA
methods, where genetic modifications include introducing or
modifying specific genes from parental varieties, or, for example,
by using transgenic breeding wherein a specific gene or genes are
introduced to a plant from a different species of plant and/or
bacteria. Another way to create genetic variation is through
mutation breeding wherein new alleles are artificially created from
endogenous genes. The artificial genes can be created by a variety
of ways including treating the plant or seeds with, for example,
chemical mutagens (e.g., using alkylating agents, epoxides,
alkaloids, peroxides, formaldehyde), irradiation (e.g., X-rays,
gamma rays, neutrons, beta particles, alpha particles, protons,
deuterons, UV radiation) and temperature shocking or other external
stressing and subsequent selection techniques. Other methods of
providing modified genes is through error prone PCR and DNA
shuffling followed by insertion of the desired modified DNA into
the desired plant or seed. Methods of introducing the desired
genetic variation in the seed or plant include, for example, the
use of a bacterial carrier, biolistics, calcium phosphate
precipitation, electroporation, gene splicing, gene silencing,
lipofection, microinjection and viral carriers. Additional
genetically modified materials have been described in U.S.
application Ser. No. 13/396,369 filed Feb. 14, 2012, the full
disclosure of which is incorporated herein by reference. Any of the
methods described herein can be practiced with mixtures of any
biomass materials described herein.
Biomass Material Preparation--Mechanical Treatments
[0046] The biomass can be in a dry form, for example with less than
about 35% moisture content (e.g., less than about 20%, less than
about 15%, less than about 10% less than about 5%, less than about
4%, less than about 3%, less than about 2% or even less than about
1%). The biomass can also be delivered in a wet state, for example
as a wet solid, a slurry or a suspension with at least about 10 wt.
% solids (e.g., at least about 20 wt. %, at least about 30 wt. %,
at least about 40 wt. %, at least about 50 wt. %, at least about 60
wt. %, at least about 70 wt. %).
[0047] The processes disclosed herein can utilize low bulk density
materials, for example cellulosic or lignocellulosic feedstocks
that have been physically pretreated to have a bulk density of less
than about 0.75 g/cm.sup.3, e.g., less than about 0.7, 0.65, 0.60,
0.50, 0.35, 0.25, 0.20, 0.15, 0.10, 0.05 or less, e.g., less than
about 0.025 g/cm.sup.3. Bulk density is determined using ASTM
D1895B. Briefly, the method involves filling a measuring cylinder
of known volume with a sample and obtaining a weight of the sample.
The bulk density is calculated by dividing the weight of the sample
in grams by the known volume of the cylinder in cubic centimeters.
If desired, low bulk density materials can be densified, for
example, by methods described in U.S. Pat. No. 7,971,809 to Medoff,
the full disclosure of which is hereby incorporated by
reference.
[0048] In some cases, the pre-treatment processing includes
screening of the biomass material. Screening can be through a mesh
or perforated plate with a desired opening size, for example, less
than about 6.35 mm (1/4 inch, 0.25 inch), (e.g., less than about
3.18 mm (1/8 inch, 0.125 inch), less than about 1.59 mm ( 1/16
inch, 0.0625 inch), is less than about 0.79 mm ( 1/32 inch, 0.03125
inch), e.g., less than about 0.51 mm ( 1/50 inch, 0.02000 inch),
less than about 0.40 mm ( 1/64 inch, 0.015625 inch), less than
about 0.23 mm (0.009 inch), less than about 0.20 mm ( 1/128 inch,
0.0078125 inch), less than about 0.18 mm (0.007 inch), less than
about 0.13 mm (0.005 inch), or even less than about 0.10 mm ( 1/256
inch, 0.00390625 inch)). In one configuration the desired biomass
falls through the perforations or screen and thus biomass larger
than the perforations or screen are not irradiated. These larger
materials can be re-processed, for example, by comminuting, or they
can simply be removed from processing. In another configuration
material that is larger than the perforations is irradiated and the
smaller material is removed by the screening process or recycled.
In this kind of a configuration, the conveyor itself (for example a
part of the conveyor) can be perforated or made with a mesh. For
example, in one particular embodiment the biomass material may be
wet and the perforations or mesh allow water to drain away from the
biomass before irradiation.
[0049] Screening of material can also be by a manual method, for
example, by an operator or mechanoid (e.g., a robot equipped with a
color, reflectivity or other sensor) that removes unwanted
material. Screening can also be by magnetic screening wherein a
magnet is disposed near the conveyed material and the magnetic
material is removed magnetically.
[0050] For example, a portion of the conveying trough can be heated
by use of a heating jacket. Heating can be, for example, for the
purpose of drying the material. In the case of drying the material,
this can also be facilitated, with or without heating, by the
movement of a gas (e.g., air, oxygen, nitrogen, He, CO.sub.2,
Argon) over and/or through the biomass as it is being conveyed.
Optionally, pre-treatment processing can include cooling the
material. Cooling material is described in U.S. Pat. No. 7,900,857
to Medoff, the disclosure of which in incorporated herein by
reference. For example, cooling can be by supplying a cooling
fluid, for example water (e.g., with glycerol), or nitrogen (e.g.,
liquid nitrogen) to the bottom of the conveying trough.
Alternatively, a cooling gas, for example, chilled nitrogen can be
blown over the biomass materials or under the conveying system.
[0051] Another optional pre-treatment processing method can include
adding a material to the biomass. The additional material can be
added by, for example, by showering, sprinkling and or pouring the
material onto the biomass as it is conveyed. Materials that can be
added include, for example, metals, ceramics and/or ions as
described in U.S. Pat. App. Pub. 2010/0105119 A1 (filed Oct. 26,
2009) and U.S. Pat. App. Pub. 2010/0159569 A1 (filed Dec. 16,
2009), the entire disclosures of which are incorporated herein by
reference. Optional materials that can be added include acids and
bases. Other materials that can be added are oxidants (e.g.,
peroxides, chlorates), polymers, polymerizable monomers (e.g.,
containing unsaturated bonds), water, catalysts, enzymes and/or
organisms. Materials can be added, for example, in pure form, as a
solution in a solvent (e.g., water or an organic solvent) and/or as
a solution. In some cases the solvent is volatile and can be made
to evaporate e.g., by heating and/or blowing gas as previously
described. The added material may form a uniform coating on the
biomass or be a homogeneous mixture of different components (e.g.,
biomass and additional material). The added material can modulate
the optional subsequent irradiation step by increasing the
efficiency of the irradiation, damping the irradiation or changing
the effect of the irradiation (e.g., from electron beams to X-rays
or heat). The method may have no impact on the irradiation but may
be useful for further downstream processing. The added material may
help in conveying the material, for example, by lowering dust
levels.
[0052] Biomass can be delivered to the conveyor (e.g., the
vibratory conveyors used in the vaults herein described) by a belt
conveyor, a pneumatic conveyor, a screw conveyor, a hopper, a pipe,
manually or by a combination of these. The biomass can, for
example, be dropped, poured and/or placed onto the conveyor by any
of these methods. In some embodiments the material is delivered to
the conveyor using an enclosed material distribution system to help
maintain a low oxygen atmosphere and/or control dust and fines.
Lofted or air suspended biomass fines and dust are undesirable
because these can form an explosion hazard or damage the window
foils of an electron gun (if such a device is used for treating the
material).
[0053] The material can be leveled to form a uniform thickness
between about 0.0312 and 5 inches (e.g., between about 0.0625 and
2.000 inches, between about 0.125 and 1 inches, between about 0.125
and 0.5 inches, between about 0.3 and 0.9 inches, between about 0.2
and 0.5 inches between about 0.25 and 1.0 inches, between about
0.25 and 0.5 inches.
[0054] In some cases, the mechanical treatment may include an
initial preparation of the feedstock as received, e.g., size
reduction of materials, such as by comminution, e.g., cutting,
grinding, shearing, pulverizing or chopping. For example, in some
cases, loose feedstock (e.g., recycled paper, starchy materials, or
switchgrass) is prepared by shearing or shredding. Mechanical
treatment may reduce the bulk density of the
carbohydrate-containing material, increase the surface area of the
carbohydrate-containing material and/or decrease one or more
dimensions of the carbohydrate-containing material.
[0055] Alternatively, or in addition, the feedstock material can be
treated with another treatment, for example chemical treatments,
such as with an acid (HCl, H.sub.2SO.sub.4, H.sub.3PO.sub.4), a
base (e.g., KOH and NaOH), a chemical oxidant (e.g., peroxides,
chlorates, ozone), irradiation, steam explosion, pyrolysis,
sonication, oxidation, chemical treatment. The treatments can be in
any order and in any sequence and combinations. For example, the
feedstock material can first be physically treated by one or more
treatment methods, e.g., chemical treatment including and in
combination with acid hydrolysis (e.g., utilizing HCl,
H.sub.2SO.sub.4, H.sub.3PO.sub.4), radiation, sonication,
oxidation, pyrolysis or steam explosion, and then mechanically
treated. This sequence can be advantageous since materials treated
by one or more of the other treatments, e.g., irradiation or
pyrolysis, tend to be more brittle and, therefore, it may be easier
to further change the structure of the material by mechanical
treatment. As another example, a feedstock material can be conveyed
through ionizing radiation using a conveyor as described herein and
then mechanically treated. Chemical treatment can remove some or
all of the lignin (for example chemical pulping) and can partially
or completely hydrolyze the material. The methods also can be used
with pre-hydrolyzed material. The methods also can be used with
material that has not been pre hydrolyzed. The methods can be used
with mixtures of hydrolyzed and non-hydrolyzed materials, for
example, with about 50% or more non-hydrolyzed material, with about
60% or more non-hydrolyzed material, with about 70% or more
non-hydrolyzed material, with about 80% or more non-hydrolyzed
material or even with 90% or more non-hydrolyzed material.
[0056] In addition to size reduction, which can be performed
initially and/or later in processing, mechanical treatment can also
be advantageous for "opening up," "stressing," breaking or
shattering the carbohydrate-containing materials, making the
cellulose of the materials more susceptible to chain scission
and/or disruption of crystalline structure during the physical
treatment.
[0057] Methods of mechanically treating the carbohydrate-containing
material include, for example, milling or grinding. Milling may be
performed using, for example, a hammer mill, ball mill, colloid
mill, conical or cone mill, disk mill, edge mill, Wiley mill, grist
mill or other mill. Grinding may be performed using, for example, a
cutting/impact type grinder. Some exemplary grinders include stone
grinders, pin grinders, coffee grinders, and burr grinders.
Grinding or milling may be provided, for example, by a
reciprocating pin or other element, as is the case in a pin mill.
Other mechanical treatment methods include mechanical ripping or
tearing, other methods that apply pressure to the fibers, and air
attrition milling. Suitable mechanical treatments further include
any other technique that continues the disruption of the internal
structure of the material that was initiated by the previous
processing steps.
[0058] Mechanical feed preparation systems can be configured to
produce streams with specific characteristics such as, for example,
specific maximum sizes, specific length-to-width, or specific
surface areas ratios. Physical preparation can increase the rate of
reactions, improve the movement of material on a conveyor, improve
the irradiation profile of the material, improve the radiation
uniformity of the material, or reduce the processing time required
by opening up the materials and making them more accessible to
processes and/or reagents, such as reagents in a solution.
[0059] The bulk density of feedstocks can be controlled (e.g.,
increased). In some situations, it can be desirable to prepare a
low bulk density material, e.g., by densifying the material (e.g.,
densification can make it easier and less costly to transport to
another site) and then reverting the material to a lower bulk
density state (e.g., after transport). The material can be
densified, for example, from less than about 0.2 g/cc to more than
about 0.9 g/cc (e.g., less than about 0.3 to more than about 0.5
g/cc, less than about 0.3 to more than about 0.9 g/cc, less than
about 0.5 to more than about 0.9 g/cc, less than about 0.3 to more
than about 0.8 g/cc, less than about 0.2 to more than about 0.5
g/cc). For example, the material can be densified by the methods
and equipment disclosed in U.S. Pat. No. 7,932,065 to Medoff and
International Publication No. WO 2008/073186 (which was filed Oct.
26, 2007, was published in English, and which designated the United
States), the full disclosures of which are incorporated herein by
reference. Densified materials can be processed by any of the
methods described herein, or any material processed by any of the
methods described herein can be subsequently densified.
[0060] In some embodiments, the material to be processed is in the
form of a fibrous material that includes fibers provided by
shearing a fiber source. For example, the shearing can be performed
with a rotary knife cutter.
[0061] For example, a fiber source, e.g., that is recalcitrant or
that has had its recalcitrance level reduced, can be sheared, e.g.,
in a rotary knife cutter, to provide a first fibrous material. The
first fibrous material is passed through a first screen, e.g.,
having an average opening size of 1.59 mm or less ( 1/16 inch,
0.0625 inch), provide a second fibrous material. If desired, the
fiber source can be cut prior to the shearing, e.g., with a
shredder. For example, when a paper is used as the fiber source,
the paper can be first cut into strips that are, e.g., 1/4- to
1/2-inch wide, using a shredder, e.g., a counter-rotating screw
shredder, such as those manufactured by Munson (Utica, N.Y.). As an
alternative to shredding, the paper can be reduced in size by
cutting to a desired size using a guillotine cutter. For example,
the guillotine cutter can be used to cut the paper into sheets that
are, e.g., 10 inches wide by 12 inches long.
[0062] In some embodiments, the shearing of the fiber source and
the passing of the resulting first fibrous material through a first
screen are performed concurrently. The shearing and the passing can
also be performed in a batch-type process.
[0063] For example, a rotary knife cutter can be used to
concurrently shear the fiber source and screen the first fibrous
material. A rotary knife cutter includes a hopper that can be
loaded with a shredded fiber source prepared by shredding a fiber
source.
[0064] In some implementations, the feedstock is physically treated
prior to saccharification and/or fermentation. Physical treatment
processes can include one or more of any of those described herein,
such as mechanical treatment, chemical treatment, irradiation,
sonication, oxidation, pyrolysis or steam explosion. Treatment
methods can be used in combinations of two, three, four, or even
all of these technologies (in any order). When more than one
treatment method is used, the methods can be applied at the same
time or at different times. Other processes that change a molecular
structure of a biomass feedstock may also be used, alone or in
combination with the processes disclosed herein.
[0065] Mechanical treatments that may be used, and the
characteristics of the mechanically treated carbohydrate-containing
materials, are described in further detail in U.S. Pat. App. Pub.
2012/0100577 A1, filed Oct. 18, 2011, the full disclosure of which
is hereby incorporated herein by reference.
Radiation Treatment
[0066] The feedstock can be treated with radiation to modify its
structure to reduce its recalcitrance. Such treatment can, for
example, reduce the average molecular weight of the feedstock,
change the crystalline structure of the feedstock, and/or increase
the surface area and/or porosity of the feedstock. Radiation can be
by, for example electron beam, ion beam, 100 nm to 28 nm
ultraviolet (UV) light, gamma or X-ray radiation. Radiation
treatments and systems for treatments are discussed in U.S. Pat.
No. 8,142,620 and U.S. patent application Ser. No. 12/417,731, the
entire disclosures of which are incorporated herein by
reference.
[0067] Each form of radiation ionizes the biomass via particular
interactions, as determined by the energy of the radiation. Heavy
charged particles primarily ionize matter via Coulomb scattering;
furthermore, these interactions produce energetic electrons that
may further ionize matter. Alpha particles are identical to the
nucleus of a helium atom and are produced by the alpha decay of
various radioactive nuclei, such as isotopes of bismuth, polonium,
astatine, radon, francium, radium, several actinides, such as
actinium, thorium, uranium, neptunium, curium, californium,
americium, and plutonium. Electrons interact via Coulomb scattering
and bremsstrahlung radiation produced by changes in the velocity of
electrons.
[0068] When particles are utilized, they can be neutral
(uncharged), positively charged or negatively charged. When
charged, the charged particles can bear a single positive or
negative charge, or multiple charges, e.g., one, two, three or even
four or more charges. In instances in which chain scission is
desired to change the molecular structure of the carbohydrate
containing material, positively charged particles may be desirable,
in part, due to their acidic nature. When particles are utilized,
the particles can have the mass of a resting electron, or greater,
e.g., 500, 1000, 1500, or 2000 or more times the mass of a resting
electron. For example, the particles can have a mass of from about
1 atomic unit to about 150 atomic units, e.g., from about 1 atomic
unit to about 50 atomic units, or from about 1 to about 25, e.g.,
1, 2, 3, 4, 5, 10, 12 or 15 atomic units.
[0069] Gamma radiation has the advantage of a significant
penetration depth into a variety of material in the sample.
[0070] In embodiments in which the irradiating is performed with
electromagnetic radiation, the electromagnetic radiation can have,
e.g., energy per photon (in electron volts) of greater than 102 eV,
e.g., greater than 103, 104, 105, 106, or even greater than 107 eV.
In some embodiments, the electromagnetic radiation has energy per
photon of between 104 and 107, e.g., between 105 and 106 eV. The
electromagnetic radiation can have a frequency of, e.g., greater
than 1016 Hz, greater than 1017 Hz, 1018, 1019, 1020, or even
greater than 1021 Hz. In some embodiments, the electromagnetic
radiation has a frequency of between 1018 and 1022 Hz, e.g.,
between 1019 to 1021 Hz.
[0071] Electron bombardment may be performed using an electron beam
device that has a nominal energy of less than 10 MeV, e.g., less
than 7 MeV, less than 5 MeV, or less than 2 MeV, e.g., from about
0.5 to 1.5 MeV, from about 0.8 to 1.8 MeV, or from about 0.7 to 1
MeV. In some implementations the nominal energy is about 500 to 800
keV.
[0072] The electron beam may have a relatively high total beam
power (the combined beam power of all accelerating heads, or, if
multiple accelerators are used, of all accelerators and all heads),
e.g., at least 25 kW, e.g., at least 30, 40, 50, 60, 65, 70, 80,
100, 125, or 150 kW. In some cases, the power is even as high as
500 kW, 750 kW, or even 1000 kW or more. In some cases the electron
beam has a beam power of 1200 kW or more, e.g., 1400, 1600, 1800,
or even 3000 kW.
[0073] This high total beam power is usually achieved by utilizing
multiple accelerating heads. For example, the electron beam device
may include two, four, or more accelerating heads. The use of
multiple heads, each of which has a relatively low beam power,
prevents excessive temperature rise in the material, thereby
preventing burning of the material, and also increases the
uniformity of the dose through the thickness of the layer of
material.
[0074] It is generally preferred that the bed of biomass material
has a relatively uniform thickness. In some embodiments the
thickness is less than about 1 inch (e.g., less than about 0.75
inches, less than about 0.5 inches, less than about 0.25 inches,
less than about 0.1 inches, between about 0.1 and 1 inch, between
about 0.2 and 0.3 inches).
[0075] It is desirable to treat the material as quickly as
possible. In general, it is preferred that treatment be performed
at a dose rate of greater than about 0.25 Mrad per second, e.g.,
greater than about 0.5, 0.75, 1, 1.5, 2, 5, 7, 10, 12, 15, or even
greater than about 20 Mrad per second, e.g., about 0.25 to 2 Mrad
per second. Higher dose rates allow a higher throughput for a
target (e.g., the desired) dose. Higher dose rates generally
require higher line speeds, to avoid thermal decomposition of the
material. In one implementation, the accelerator is set for 3 MeV,
50 mA beam current, and the line speed is 24 feet/minute, for a
sample thickness of about 20 mm (e.g., comminuted corn cob material
with a bulk density of 0.5 g/cm3).
[0076] In some embodiments, electron bombardment is performed until
the material receives a total dose of at least 0.1 Mrad, 0.25 Mrad,
1 Mrad, 5 Mrad, e.g., at least 10, 20, 30 or at least 40 Mrad. In
some embodiments, the treatment is performed until the material
receives a dose of from about 10 Mrad to about 50 Mrad, e.g., from
about 20 Mrad to about 40 Mrad, or from about 25 Mrad to about 30
Mrad. In some implementations, a total dose of 25 to 35 Mrad is
preferred, applied ideally over a couple of passes, e.g., at 5
Mrad/pass with each pass being applied for about one second.
Cooling methods, systems and equipment can be utilized before,
after, during and/or between irradiations (e.g., cooled screw
conveyors and cooled vibratory conveyors).
[0077] Using multiple heads as discussed above, the material can be
treated in multiple passes, for example, two passes at 10 to 20
Mrad/pass, e.g., 12 to 18 Mrad/pass, separated by a few seconds of
cool-down, or three passes of 7 to 12 Mrad/pass, e.g., 5 to 20
Mrad/pass, 10 to 40 Mrad/pass, 9 to 11 Mrad/pass. As discussed
herein, treating the material with several relatively low doses,
rather than one high dose, tends to prevent overheating of the
material and also increases dose uniformity through the thickness
of the material. In some implementations, the material is stirred
or otherwise mixed during or after each pass and then smoothed into
a uniform layer again before the next pass, to further enhance
treatment uniformity.
[0078] In some embodiments, electrons are accelerated to, for
example, a speed of greater than 75 percent of the speed of light,
e.g., greater than 85, 90, 95, or 99 percent of the speed of
light.
[0079] In some embodiments, any processing described herein occurs
on lignocellulosic material that remains dry as acquired or that
has been dried, e.g., using heat and/or reduced pressure. For
example, in some embodiments, the cellulosic and/or lignocellulosic
material has less than about 25 wt. % retained water, measured at
25 C and at fifty percent relative humidity (e.g., less than about
20 wt. %, less than about 15 wt. %, less than about 14 wt. %, less
than about 13 wt. %, less than about 12 wt. %, less than about 10
wt. %, less than about 9 wt. %, less than about 8 wt. %, less than
about 7 wt. %, less than about 6 wt. %, less than about 5 wt. %,
less than about 4 wt. %, less than about 3 wt. %, less than about 2
wt. %, less than about 1 wt. %, or less than about 0.5 wt. %.
[0080] In some embodiments, two or more ionizing sources can be
used, such as two or more electron sources. For example, samples
can be treated, in any order, with a beam of electrons, followed by
gamma radiation and UV light having wavelengths from about 100 nm
to about 280 nm. In some embodiments, samples are treated with
three ionizing radiation sources, such as a beam of electrons,
gamma radiation, and energetic UV light. The biomass is conveyed
through the treatment zone where it can be bombarded with
electrons.
[0081] It may be advantageous to repeat the treatment to more
thoroughly reduce the recalcitrance of the biomass and/or further
modify the biomass. In particular the process parameters can be
adjusted after a first (e.g., second, third, fourth or more) pass
depending on the recalcitrance of the material. In some
embodiments, a conveyor can be used which includes a circular
system where the biomass is conveyed multiple times through the
various processes described above. In some other embodiments
multiple treatment devices (e.g., electron beam generators) are
used to treat the biomass multiple (e.g., 2, 3, 4 or more) times.
In yet other embodiments, a single electron beam generator may be
the source of multiple beams (e.g., 2, 3, 4 or more beams) that can
be used for treatment of the biomass.
[0082] The effectiveness in changing the molecular/supermolecular
structure and/or reducing the recalcitrance of the
carbohydrate-containing biomass depends on the electron energy used
and the dose applied, while exposure time depends on the power and
dose. In some embodiments, the dose rate and total dose are
adjusted so as not to destroy (e.g., char or burn) the biomass
material. For example, the carbohydrates should not be damaged in
the processing so that they can be released from the biomass
intact, e.g. as monomeric sugars.
[0083] In some embodiments, the treatment (with any electron source
or a combination of sources) is performed until the material
receives a dose of at least about 0.05 Mrad, e.g., at least about
0.1, 0.25, 0.5, 0.75, 1.0, 2.5, 5.0, 7.5, 10.0, 15, 20, 25, 30, 40,
50, 60, 70, 80, 90, 100, 125, 150, 175, or 200 Mrad. In some
embodiments, the treatment is performed until the material receives
a dose of between 0.1-100 Mrad, 1-200, 5-200, 10-200, 5-150, 50-150
Mrad, 5-100, 5-50, 5-40, 10-50, 10-75, 15-50, 20-35 Mrad.
[0084] In some embodiments, relatively low doses of radiation are
utilized, e.g., to increase the molecular weight of a cellulosic or
lignocellulosic material (with any radiation source or a
combination of sources described herein). For example, a dose of at
least about 0.05 Mrad, e.g., at least about 0.1 Mrad or at least
about 0.25, 0.5, 0.75, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, or at
least about 5.0 Mrad. In some embodiments, the irradiation is
performed until the material receives a dose of between 0.1 Mrad
and 2.0 Mrad, e.g., between 0.5 Mrad and 4.0 Mrad or between 1.0
Mrad and 3.0 Mrad. It also can be desirable to irradiate from
multiple directions, simultaneously or sequentially, in order to
achieve a desired degree of penetration of radiation into the
material. For example, depending on the density and moisture
content of the material, such as wood, and the type of radiation
source used (e.g., gamma or electron beam), the maximum penetration
of radiation into the material may be only about 0.75 inch. In such
instances, a thicker section (up to 1.5 inch) can be irradiated by
first irradiating the material from one side, and then turning the
material over and irradiating from the other side. Irradiation from
multiple directions can be particularly useful with electron beam
radiation, which irradiates faster than gamma radiation but
typically does not achieve as great a penetration depth.
Radiation Opaque Materials
[0085] The invention can include processing the material (e.g., for
some of the processing steps) in a vault and/or bunker that is
constructed using radiation opaque materials. In some
implementations, the radiation opaque materials are selected to be
capable of shielding the components from X-rays with high energy
(short wavelength), which can penetrate many materials. One
important factor in designing a radiation shielding enclosure is
the attenuation length of the materials used, which will determine
the required thickness for a particular material, blend of
materials, or layered structure. The attenuation length is the
penetration distance at which the radiation is reduced to
approximately 1/e (e=Euler's number) times that of the incident
radiation. Although virtually all materials are radiation opaque if
thick enough, materials containing a high compositional percentage
(e.g., density) of elements that have a high Z value (atomic
number) have a shorter radiation attenuation length and thus if
such materials are used a thinner, lighter shielding can be
provided. Examples of high Z value materials that are used in
radiation shielding are tantalum and lead. Another important
parameter in radiation shielding is the halving distance, which is
the thickness of a particular material that will reduce gamma ray
intensity by 50%. As an example for X-ray radiation with an energy
of 0.1 MeV the halving thickness is about 15.1 mm for concrete and
about 2.7 mm for lead, while with an X-ray energy of 1 MeV the
halving thickness for concrete is about 44.45 mm and for lead is
about 7.9 mm Radiation opaque materials can be materials that are
thick or thin so long as they can reduce the radiation that passes
through to the other side. Thus, if it is desired that a particular
enclosure have a low wall thickness, e.g., for light weight or due
to size constraints, the material chosen should have a sufficient Z
value and/or attenuation length so that its halving length is less
than or equal to the desired wall thickness of the enclosure.
[0086] In some cases, the radiation opaque material may be a
layered material, for example having a layer of a higher Z value
material, to provide good shielding, and a layer of a lower Z value
material to provide other properties (e.g., structural integrity,
impact resistance, etc.). In some cases, the layered material may
be a "graded-T" laminate, e.g., including a laminate in which the
layers provide a gradient from high-Z through successively lower-Z
elements. In some cases the radiation opaque materials can be
interlocking blocks, for example, lead and/or concrete blocks can
be supplied by NELCO Worldwide (Burlington, Mass.), and
reconfigurable vaults can be utilized.
[0087] A radiation opaque material can reduce the radiation passing
through a structure (e.g., a wall, door, ceiling, enclosure, a
series of these or combinations of these) formed of the material by
about at least about 10%, (e.g., at least about 20%, at least about
30%, at least about 40%, at least about 50%, at least about 60%, at
least about 70%, at least about 80%, at least about 90%, at least
about 95%, at least about 96%, at least about 97%, at least about
98%, at least about 99%, at least about 99.9%, at least about
99.99%, at least about 99.999%) as compared to the incident
radiation. Therefore, an enclosure made of a radiation opaque
material can reduce the exposure of equipment/system/components by
the same amount. Radiation opaque materials can include stainless
steel, metals with Z values above 25 (e.g., lead, iron), concrete,
dirt, and combinations thereof. Radiation opaque materials can
include a barrier in the direction of the incident radiation of at
least about 1 mm (e.g., 5 mm, 10 mm, 5 cm, 10 cm, 100 cm, 1 m or
even about 10 m).
Radiation Sources
[0088] The type of radiation determines the kinds of radiation
sources used as well as the radiation devices and associated
equipment. The methods, systems and equipment described herein, for
example for treating materials with radiation, can utilized sources
as described herein as well as any other useful source.
[0089] Sources of gamma rays include radioactive nuclei, such as
isotopes of cobalt, calcium, technetium, chromium, gallium, indium,
iodine, iron, krypton, samarium, selenium, sodium, thallium, and
xenon.
[0090] Sources of X-rays include electron beam collision with metal
targets, such as tungsten or molybdenum or alloys, or compact light
sources, such as those produced commercially by Lyncean.
[0091] Alpha particles are identical to the nucleus of a helium
atom and are produced by the alpha decay of various radioactive
nuclei, such as isotopes of bismuth, polonium, astatine, radon,
francium, radium, several actinides, such as actinium, thorium,
uranium, neptunium, curium, californium, americium, and
plutonium.
[0092] Sources for ultraviolet radiation include deuterium or
cadmium lamps.
[0093] Sources for infrared radiation include sapphire, zinc, or
selenide window ceramic lamps.
[0094] Sources for microwaves include klystrons, Slevin type RF
sources, or atom beam sources that employ hydrogen, oxygen, or
nitrogen gases.
[0095] Accelerators used to accelerate the particles (e.g.,
electrons or ions) can be DC (e.g., electrostatic DC or
electrodynamic DC), RF linear, magnetic induction linear or
continuous wave. For example, various irradiating devices may be
used in the methods disclosed herein, including field ionization
sources, electrostatic ion separators, field ionization generators,
thermionic emission sources, microwave discharge ion sources,
recirculating or static accelerators, dynamic linear accelerators,
van de Graaff accelerators, Cockroft Walton accelerators (e.g.,
PELLETRON.RTM. accelerators), LINACS, Dynamitrons (e.g.,
DYNAMITRON.RTM. accelerators), cyclotrons, synchrotrons, betatrons,
transformer-type accelerators, microtrons, plasma generators,
cascade accelerators, and folded tandem accelerators. For example,
cyclotron type accelerators are available from IBA, Belgium, such
as the RHODOTRON.TM. system, while DC type accelerators are
available from RDI, now IBA Industrial, such as the
DYNAMITRON.RTM.. Other suitable accelerator systems include, for
example: DC insulated core transformer (ICT) type systems,
available from Nissin High Voltage, Japan; S-band LINACs, available
from L3-PSD (USA), Linac Systems (France), Mevex (Canada), and
Mitsubishi Heavy Industries (Japan); L-band LINACs, available from
Iotron Industries (Canada); and ILU-based accelerators, available
from Budker Laboratories (Russia). Ions and ion accelerators are
discussed in Introductory Nuclear Physics, Kenneth S. Krane, John
Wiley & Sons, Inc. (1988), Krsto Prelec, FIZIKA B 6 (1997) 4,
177-206, Chu, William T., "Overview of Light-Ion Beam Therapy",
Columbus-Ohio, ICRU-IAEA Meeting, 18-20 Mar. 2006, Iwata, Y. et
al., "Alternating-Phase-Focused IH-DTL for Heavy-Ion Medical
Accelerators", Proceedings of EPAC 2006, Edinburgh, Scotland, and
Leitner, C. M. et al., "Status of the Superconducting ECR Ion
Source Venus", Proceedings of EPAC 2000, Vienna, Austria. Some
particle accelerators and their uses are disclosed, for example, in
U.S. Pat. No. 7,931,784 to Medoff, the complete disclosure of which
is incorporated herein by reference.
[0096] Electrons may be produced by radioactive nuclei that undergo
beta decay, such as isotopes of iodine, cesium, technetium, and
iridium. Alternatively, an electron gun can be used as an electron
source via thermionic emission and accelerated through an
accelerating potential. An electron gun generates electrons, which
are then accelerated through a large potential (e.g., greater than
about 500 thousand, greater than about 1 million, greater than
about 2 million, greater than about 5 million, greater than about 6
million, greater than about 7 million, greater than about 8
million, greater than about 9 million, or even greater than 10
million volts) and then scanned magnetically in the x-y plane,
where the electrons are initially accelerated in the z direction
down the accelerator tube and extracted through a foil window.
Scanning the electron beams is useful for increasing the
irradiation surface when irradiating materials, e.g., a biomass,
that is conveyed through the scanned beam. Scanning the electron
beam also distributes the thermal load homogenously on the window
and helps reduce the foil window rupture due to local heating by
the electron beam. Window foil rupture is a cause of significant
down-time due to subsequent necessary repairs and re-starting the
electron gun.
[0097] Various other irradiating devices may be used in the methods
disclosed herein, including field ionization sources, electrostatic
ion separators, field ionization generators, thermionic emission
sources, microwave discharge ion sources, recirculating or static
accelerators, dynamic linear accelerators, van de Graaff
accelerators, and folded tandem accelerators. Such devices are
disclosed, for example, in U.S. Pat. No. 7,931,784 to Medoff, the
complete disclosure of which is incorporated herein by
reference.
[0098] A beam of electrons can be used as the radiation source. A
beam of electrons has the advantages of high dose rates (e.g., 1,
5, or even 10 Mrad per second), high throughput, less containment,
and less confinement equipment. Electron beams can also have high
electrical efficiency (e.g., 80%), allowing for lower energy usage
relative to other radiation methods, which can translate into a
lower cost of operation and lower greenhouse gas emissions
corresponding to the smaller amount of energy used. Electron beams
can be generated, e.g., by electrostatic generators, cascade
generators, transformer generators, low energy accelerators with a
scanning system, low energy accelerators with a linear cathode,
linear accelerators, and pulsed accelerators.
[0099] Electrons can also be more efficient at causing changes in
the molecular structure of carbohydrate-containing materials, for
example, by the mechanism of chain scission. In addition, electrons
having energies of 0.5-10 MeV can penetrate low density materials,
such as the biomass materials described herein, e.g., materials
having a bulk density of less than 0.5 g/cm3, and a depth of 0.3-10
cm. Electrons as an ionizing radiation source can be useful, e.g.,
for relatively thin piles, layers or beds of materials, e.g., less
than about 0.5 inch, e.g., less than about 0.4 inch, 0.3 inch, 0.25
inch, or less than about 0.1 inch. In some embodiments, the energy
of each electron of the electron beam is from about 0.3 MeV to
about 2.0 MeV (million electron volts), e.g., from about 0.5 MeV to
about 1.5 MeV, or from about 0.7 MeV to about 1.25 MeV. Methods of
irradiating materials are discussed in U.S. Pat. App. Pub.
2012/0100577 A1, filed Oct. 18, 2011, the entire disclosure of
which is herein incorporated by reference.
[0100] Tradeoffs in considering electron beam irradiation device
power specifications include cost to operate, capital costs,
depreciation, and device footprint. Tradeoffs in considering
exposure dose levels of electron beam irradiation would be energy
costs and environment, safety, and health (ESH) concerns.
Typically, generators are housed in a vault, e.g., of lead or
concrete, especially for production from X-rays that are generated
in the process. Tradeoffs in considering electron energies include
energy costs.
The electron beam irradiation device can produce either a fixed
beam or a scanning beam. A scanning beam may be advantageous with
large scan sweep length and high scan speeds, as this would
effectively replace a large, fixed beam width. Further, available
sweep widths of 0.5 m, 1 m, 2 m or more are available. The scanning
beam is preferred in most embodiments described herein because of
the larger scan width and reduced possibility of local heating and
failure of the windows.
Electron Guns--Windows
[0101] The extraction system for an electron accelerator can
include two window foils. The cooling gas in the two foil window
extraction system can be a purge gas or a mixture, for example air,
or a pure gas. In one embodiment the gas is an inert gas such as
nitrogen, argon, helium and or carbon dioxide. It is preferred to
use a gas rather than a liquid since energy losses to the electron
beam are minimized. Mixtures of pure gas can also be used, either
pre-mixed or mixed in line prior to impinging on the windows or in
the space between the windows. The cooling gas can be cooled, for
example, by using a heat exchange system (e.g., a chiller) and/or
by using boil off from a condensed gas (e.g., liquid nitrogen,
liquid helium). Window foils are described in PCT/US2013/64332
filed Oct. 10, 2013 the full disclosure of which is incorporated by
reference herein
[0102] When using an enclosure, the enclosed conveyor can also be
purged with an inert gas so as to maintain an atmosphere at a
reduced oxygen level. Keeping oxygen levels low avoids the
formation of ozone which in some instances is undesirable due to
its reactive and toxic nature. For example the oxygen can be less
than about 20% (e.g., less than about 10%, less than about 1%, less
than about 0.1%, less than about 0.01%, or even less than about
0.001% oxygen). Purging can be done with an inert gas including,
but not limited to, nitrogen, argon, helium or carbon dioxide. This
can be supplied, for example, from a boil off of a liquid source
(e.g., liquid nitrogen or helium), generated or separated from air
in situ, or supplied from tanks. The inert gas can be recirculated
and any residual oxygen can be removed using a catalyst, such as a
copper catalyst bed. Alternatively, combinations of purging,
recirculating and oxygen removal can be done to keep the oxygen
levels low.
[0103] The enclosure can also be purged with a reactive gas that
can react with the biomass. This can be done before, during or
after the irradiation process. The reactive gas can be, but is not
limited to, nitrous oxide, ammonia, oxygen, ozone, hydrocarbons,
aromatic compounds, amides, peroxides, azides, halides, oxyhalides,
phosphides, phosphines, arsines, sulfides, thiols, boranes and/or
hydrides. The reactive gas can be activated in the enclosure, e.g.,
by irradiation (e.g., electron beam, UV irradiation, microwave
irradiation, heating, IR radiation), so that it reacts with the
biomass. The biomass itself can be activated, for example by
irradiation. Preferably the biomass is activated by the electron
beam, to produce radicals which then react with the activated or
unactivated reactive gas, e.g., by radical coupling or
quenching.
[0104] Purging gases supplied to an enclosed conveyor can also be
cooled, for example below about 25.degree. C., below about
0.degree. C., below about -40.degree. C., below about -80.degree.
C., below about -120.degree. C. For example, the gas can be boiled
off from a compressed gas such as liquid nitrogen or sublimed from
solid carbon dioxide. As an alternative example, the gas can be
cooled by a chiller or part of or the entire conveyor can be
cooled.
Heating and Throughput During Radiation Treatment
[0105] Several processes can occur in biomass when electrons from
an electron beam interact with matter in inelastic collisions. For
example, ionization of the material, chain scission of polymers in
the material, cross linking of polymers in the material, oxidation
of the material, generation of X-rays ("Bremsstrahlung") and
vibrational excitation of molecules (e.g. phonon generation).
Without being bound to a particular mechanism, the reduction in
recalcitrance can be due to several of these inelastic collision
effects, for example ionization, chain scission of polymers,
oxidation and phonon generation. Some of the effects (e.g.,
especially X-ray generation), necessitate shielding and engineering
barriers, for example, enclosing the irradiation processes in a
concrete (or other radiation opaque material) vault. Another effect
of irradiation, vibrational excitation, is equivalent to heating up
the sample. Heating the sample by irradiation can help in
recalcitrance reduction, but excessive heating can destroy the
material, as will be explained below.
[0106] The adiabatic temperature rise (.DELTA.T) from adsorption of
ionizing radiation is given by the equation: .DELTA.T=D/Cp: where D
is the average dose in kGy, Cp is the heat capacity in J/g.degree.
C., and .DELTA.T is the change in temperature in .degree. C. A
typical dry biomass material will have a heat capacity close to 2.
Wet biomass will have a higher heat capacity dependent on the
amount of water since the heat capacity of water is very high (4.19
J/g.degree. C.). Metals have much lower heat capacities, for
example 304 stainless steel has a heat capacity of 0.5 J/g.degree.
C. The temperature change due to the instant adsorption of
radiation in a biomass and stainless steel for various doses of
radiation is shown in Table 1.
TABLE-US-00001 TABLE 1 Calculated Temperature increase for biomass
and stainless steel. Dose (Mrad) Estimated Biomass .DELTA.T
(.degree. C.) Steel .DELTA.T (.degree. C.) 10 50 200 50 250,
Decomposition 1000 100 500, Decomposition 2000 150 750,
Decomposition 3000 200 1000, Decomposition 4000
[0107] High temperatures can destroy and or modify the biopolymers
in biomass so that the polymers (e.g., cellulose) are unsuitable
for further processing. A biomass subjected to high temperatures
can become dark, sticky and give off odors indicating
decomposition. The stickiness can even make the material hard to
convey. The odors can be unpleasant and be a safety issue. In fact,
keeping the biomass below about 200.degree. C. has been found to be
beneficial in the processes described herein (e.g., below about
190.degree. C., below about 180.degree. C., below about 170.degree.
C., below about 160.degree. C., below about 150.degree. C., below
about 140.degree. C., below about 130.degree. C., below about
120.degree. C., below about 110.degree. C., between about
60.degree. C. and 180.degree. C., between about 60.degree. C. and
160.degree. C., between about 60.degree. C. and 150.degree. C.,
between about 60.degree. C. and 140.degree. C., between about
60.degree. C. and 130.degree. C., between about 60.degree. C. and
120.degree. C., between about 80.degree. C. and 180.degree. C.,
between about 100.degree. C. and 180.degree. C., between about
120.degree. C. and 180.degree. C., between about 140.degree. C. and
180.degree. C., between about 160.degree. C. and 180.degree. C.,
between about 100.degree. C. and 140.degree. C., between about
80.degree. C. and 120.degree. C.).
[0108] It has been found that irradiation above about 10 Mrad is
desirable for the processes described herein (e.g., reduction of
recalcitrance). A high throughput is also desirable so that the
irradiation does not become a bottle neck in processing the
biomass. The treatment is governed by a dose rate equation:
M=FP/D*time, where M is the mass of irradiated material (Kg), F is
the fraction of power that is adsorbed (unit less), P is the
emitted power (KW=Voltage in MeV*Current in mA), time is the
treatment time (sec) and D is the adsorbed dose (KGy). In an
exemplary process where the fraction of adsorbed power is fixed,
the Power emitted is constant and a set dosage is desired, the
throughput (e.g., M, the biomass processed) can be increased by
increasing the irradiation time. However, increasing the
irradiation time without allowing the material to cool, can
excessively heat the material as exemplified by the calculations
shown above. Since biomass has a low thermal conductivity (less
than about 0.1 Wm.sup.-1K.sup.-1), heat dissipation is slow,
unlike, for example metals (greater than about 10
Wm.sup.-1K.sup.-1) which can dissipate energy quickly as long as
there is a heat sink to transfer the energy to.
Electron Guns--Beam Stops
[0109] In some embodiments the systems and methods include a beam
stop (e.g., a shutter). For example, the beam stop can be used to
quickly stop or reduce the irradiation of material without powering
down the electron beam device. Alternatively the beam stop can be
used while powering up the electron beam, e.g., the beam stop can
stop the electron beam until a beam current of a desired level is
achieved. The beam stop can be placed between the primary foil
window and a secondary foil window. For example the beam stop can
be mounted so that it is movable, that is, so that it can be moved
into and out of the beam path. Even partial coverage of the beam
can be used, for example, to control the dose of irradiation. The
beam stop can be mounted to the floor, to a conveyor for the
biomass, to a wall, to the radiation device (e.g., at the scan
horn), or to any structural support. Preferably the beam stop is
fixed in relation to the scan horn so that the beam can be
effectively controlled by the beam stop. The beam stop can
incorporate a hinge, a rail, wheels, slots, or other means allowing
for its operation in moving into and out of the beam. The beam stop
can be made of any material that will stop at least 5% of the
electrons, e.g., at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, at
least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or
even about 100% of the electrons.
[0110] The beam stop can be made of a metal including, but not
limited to, stainless steel, lead, iron, molybdenum, silver, gold,
titanium, aluminum, tin, or alloys of these, or laminates (layered
materials) made with such metals (e.g., metal-coated ceramic,
metal-coated polymer, metal-coated composite, multilayered metal
materials).
[0111] The beam stop can be cooled, for example, with a cooling
fluid such as an aqueous solution or a gas. The beam stop can be
partially or completely hollow, for example with cavities. Interior
spaces of the beam stop can be used for cooling fluids and gases.
The beam stop can be of any shape, including flat, curved, round,
oval, square, rectangular, beveled and wedged shapes.
[0112] The beam stop can have perforations so as to allow some
electrons through, thus controlling (e.g., reducing) the levels of
radiation across the whole area of the window, or in specific
regions of the window. The beam stop can be a mesh formed, for
example, from fibers or wires. Multiple beam stops can be used,
together or independently, to control the irradiation. The beam
stop can be remotely controlled, e.g., by radio signal or hard
wired to a motor for moving the beam into or out of position.
Sonication, Pyrolysis, Oxidation, Steam Explosion
[0113] If desired, one or more sonication, pyrolysis, oxidative, or
steam explosion processes can be used instead of or in addition to
irradiation to reduce or further reduce the recalcitrance of the
carbohydrate-containing material. For example, these processes can
be applied before, during and or after irradiation. These processes
are described in detail in U.S. Pat. No. 7,932,065 to Medoff, the
full disclosure of which is incorporated herein by reference.
Use of Treated Biomass Material
[0114] Using the methods described herein, a starting biomass
material (e.g., plant biomass, animal biomass, paper, and municipal
waste biomass) can be used as feedstock to produce useful
intermediates and products such as organic acids, salts of organic
acids, anhydrides, esters of organic acids and fuels, e.g., fuels
for internal combustion engines or feedstocks for fuel cells.
Systems and processes are described herein that can use as
feedstock cellulosic and/or lignocellulosic materials that are
readily available, but often can be difficult to process, e.g.,
municipal waste streams and waste paper streams, such as streams
that include newspaper, kraft paper, corrugated paper or mixtures
of these.
[0115] In order to convert the feedstock to a form that can be
readily processed, the glucan- or xylan-containing cellulose in the
feedstock can be hydrolyzed to low molecular weight carbohydrates,
such as sugars, by a saccharifying agent, e.g., an enzyme or acid,
a process referred to as saccharification. The low molecular weight
carbohydrates can then be used, for example, in an existing
manufacturing plant, such as a single cell protein plant, an enzyme
manufacturing plant, or a fuel plant, e.g., an ethanol
manufacturing facility.
[0116] The feedstock can be hydrolyzed using an enzyme, e.g., by
combining the materials and the enzyme in a solvent, e.g., in an
aqueous solution.
[0117] Alternatively, the enzymes can be supplied by organisms that
break down biomass, such as the cellulose and/or the lignin
portions of the biomass, contain or manufacture various
cellulolytic enzymes (cellulases), ligninases or various small
molecule biomass-degrading metabolites. These enzymes may be a
complex of enzymes that act synergistically to degrade crystalline
cellulose or the lignin portions of biomass. Examples of
cellulolytic enzymes include: endoglucanases, cellobiohydrolases,
and cellobiases (beta-glucosidases).
[0118] During saccharification a cellulosic substrate can be
initially hydrolyzed by endoglucanases at random locations
producing oligomeric intermediates. These intermediates are then
substrates for exo-splitting glucanases such as cellobiohydrolase
to produce cellobiose from the ends of the cellulose polymer.
Cellobiose is a water-soluble 1,4-linked dimer of glucose. Finally,
cellobiase cleaves cellobiose to yield glucose. The efficiency
(e.g., time to hydrolyze and/or completeness of hydrolysis) of this
process depends on the recalcitrance of the cellulosic
material.
Intermediates and Products
[0119] Using the processes described herein, the biomass material
can be converted to one or more products, such as energy, fuels,
foods and materials. Specific examples of products include, but are
not limited to, hydrogen, sugars (e.g., glucose, xylose, arabinose,
mannose, galactose, fructose, disaccharides, oligosaccharides and
polysaccharides), alcohols (e.g., monohydric alcohols or dihydric
alcohols, such as ethanol, n-propanol, isobutanol, sec-butanol,
tert-butanol or n-butanol), hydrated or hydrous alcohols (e.g.,
containing greater than 10%, 20%, 30% or even greater than 40%
water), biodiesel, organic acids (see below), hydrocarbons (e.g.,
methane, ethane, propane, isobutene, pentane, n-hexane, biodiesel,
bio-gasoline and mixtures thereof), co-products (e.g., proteins,
such as cellulolytic proteins (enzymes) or single cell proteins),
and mixtures of any of these in any combination or relative
concentration, and optionally in combination with any additives
(e.g., fuel additives). Other examples include carboxylic acids,
salts of a carboxylic acid, a mixture of carboxylic acids and salts
of carboxylic acids and esters of carboxylic acids (e.g., methyl,
ethyl and n-propyl esters), ketones (e.g., acetone), aldehydes
(e.g., acetaldehyde), alpha and beta unsaturated acids (e.g.,
acrylic acid) and olefins (e.g., ethylene). Other alcohols and
alcohol derivatives include propanol, propylene glycol,
1,4-butanediol, 1,3-propanediol, sugar alcohols (e.g., erythritol,
glycol, glycerol, sorbitol threitol, arabitol, ribitol, mannitol,
dulcitol, fucitol, iditol, isomalt, maltitol, lactitol, xylitol and
other polyols), and methyl or ethyl esters of any of these
alcohols. Other products include methyl acrylate, methyl
methacrylate, lactic acid, citric acid, formic acid, acetic acid,
propionic acid, lactic acid, tartaric acid, butyric acid, succinic
acid, valeric acid, caproic acid, 3-hydroxypropionic acid, palmitic
acid, stearic acid, oxalic acid, malonic acid, glutaric acid, oleic
acid, linoleic acid, glycolic acid, gamma-hydroxybutyric acid, and
mixtures thereof, salts of any of these acids, mixtures of any of
the acids and their respective salts. These acids include isomers
of the acids and where stereochemical isomers are possible are also
included (e.g. D- and L-lactic acid, D-, L-, and meso tartaric
acid
[0120] Any combination of the above products with each other,
and/or of the above products with other products, which other
products may be made by the processes described herein or
otherwise, may be packaged together and sold as products. The
products may be combined, e.g., mixed, blended or co-dissolved, or
may simply be packaged or sold together.
[0121] Any of the products or combinations of products described
herein may be sanitized or sterilized prior to selling the
products, e.g., after purification or isolation or even after
packaging, to neutralize one or more potentially undesirable
contaminants that could be present in the product(s). Such
sanitation can be done with electron bombardment, for example, be
at a dosage of less than about 20 Mrad, e.g., from about 0.1 to 15
Mrad, from about 0.5 to 7 Mrad, or from about 1 to 3 Mrad.
[0122] The processes described herein can produce various
by-product streams useful for generating steam and electricity to
be used in other parts of the plant (co-generation) or sold on the
open market. For example, steam generated from burning by-product
streams can be used in a distillation process. As another example,
electricity generated from burning by-product streams can be used
to power electron beam generators used in pretreatment.
[0123] The by-products used to generate steam and electricity are
derived from a number of sources throughout the process. For
example, anaerobic digestion of wastewater can produce a biogas
high in methane and a small amount of waste biomass (sludge). As
another example, post-saccharification and/or post-distillate
solids (e.g., unconverted lignin, cellulose, and hemicellulose
remaining from the pretreatment and primary processes) can be used,
e.g., burned, as a fuel.
[0124] Other intermediates and products, including food and
pharmaceutical products, are described in U.S. Pat. App. Pub.
2010/0124583 A1, published May 20, 2010, to Medoff, the full
disclosure of which is hereby incorporated by reference herein.
Biomass Processing after Irradiation
[0125] After irradiation the biomass may be transferred to a vessel
for saccharification. Alternately, the biomass can be heated after
the biomass is irradiated prior to the saccharification step. The
heated means can be created, for example, by IR radiation,
microwaves, combustion (e.g., gas, coal, oil, biomass), resistive
heating and/or inductive coils. The heat can be applied from at
least one side or more than one side, can be continuous or periodic
and can be for only a portion of the material or all the material.
The biomass may be heated to temperatures above 90.degree. C. in an
aqueous liquid that may have an acid or a base present. For
example, the aqueous biomass slurry may be heated to 90 to
150.degree. C., alternatively, 105 to 145.degree. C., optionally
110 to 140.degree. C. or further optionally from 115 to 135.degree.
C. The time that the aqueous biomass mixture is held at the peak
temperature is 1 to 12 hours, alternately, 1 to 6 hours, optionally
1 to 4 hours at the peak temperature. In some instances, the
aqueous biomass mixture is acidic, and the pH is between 1 and 5,
optionally 1 to 4, or alternately, 2 to 3. In other instances, the
aqueous biomass mixture is alkaline and the pH is between 6 and 13,
alternately, 8 to 12, or optionally, 8 to 11.
Saccharification
[0126] The treated biomass materials can be saccharified, generally
by combining the material and a cellulase enzyme in a fluid or
liquid medium, e.g., an aqueous solution. In some cases, the
material is boiled, steeped, or cooked in hot water prior to
saccharification, as described in U.S. Pat. App. Pub. 2012/0100577
A1 by Medoff and Masterman, published on Apr. 26, 2012, the entire
contents of which are incorporated herein.
[0127] The saccharification process can be partially or completely
performed in a tank (e.g., a tank having a volume of at least 4000,
40,000, or 500,000 L) in a manufacturing plant, and/or can be
partially or completely performed in transit, e.g., in a rail car,
tanker truck, or in a supertanker or the hold of a ship. The time
required for complete saccharification will depend on the process
conditions and the carbohydrate-containing material and enzyme
used. If saccharification is performed in a manufacturing plant
under controlled conditions, the cellulose may be substantially
entirely converted to sugar, e.g., glucose in about 12-96 hours. If
saccharification is performed partially or completely in transit,
saccharification may take longer.
[0128] It is generally preferred that the tank contents be mixed
during saccharification, e.g., using jet mixing as described in
International App. No. PCT/US2010/035331, filed May 18, 2010, which
was published in English as WO 2010/135380 and designated the
United States, the full disclosure of which is incorporated by
reference herein.
[0129] The addition of surfactants can enhance the rate of
saccharification. Examples of surfactants include non-ionic
surfactants, such as a Tween.RTM. 20 or Tween.RTM. 80 polyethylene
glycol surfactants, ionic surfactants, or amphoteric
surfactants.
[0130] It is generally preferred that the concentration of the
sugar solution resulting from saccharification be relatively high,
e.g., greater than 40%, or greater than 50, 60, 70, 80, 90 or even
greater than 95% by dry weight basis. Water may be removed, e.g.,
by evaporation, to increase the concentration of the sugar
solution. This reduces the volume to be shipped, and also inhibits
microbial growth in the solution.
[0131] Alternatively, sugar solutions of lower concentrations may
be used, in which case it may be desirable to add an antimicrobial
additive, e.g., a broad spectrum antibiotic, in a low
concentration, e.g., 50 to 150 ppm. Other suitable antibiotics
include amphotericin B, ampicillin, chloramphenicol, ciprofloxacin,
gentamicin, hygromycin B, kanamycin, neomycin, penicillin,
puromycin, streptomycin. Antibiotics will inhibit growth of
microorganisms during transport and storage, and can be used at
appropriate concentrations, e.g., between 15 and 1000 ppm by
weight, e.g., between 25 and 500 ppm, or between 50 and 150 ppm. If
desired, an antibiotic can be included even if the sugar
concentration is relatively high. Alternatively, other additives
with anti-microbial of preservative properties may be used.
Preferably the antimicrobial additive(s) are food-grade.
[0132] A relatively high concentration solution can be obtained by
limiting the amount of water added to the carbohydrate-containing
material with the enzyme. The concentration can be controlled,
e.g., by controlling how much saccharification takes place. For
example, concentration can be increased by adding more
carbohydrate-containing material to the solution. In order to keep
the sugar that is being produced in solution, a surfactant can be
added, e.g., one of those discussed above. Solubility can also be
increased by increasing the temperature of the solution. For
example, the solution can be maintained at a temperature of
40-50.degree. C., 60-80.degree. C., or even higher.
Saccharifying Agents
[0133] Suitable cellulolytic enzymes include cellulases from
species in the genera Bacillus, Coprinus, Myceliophthora,
Cephalosporium, Scytalidium, Penicillium, Aspergillus, Pseudomonas,
Humicola, Fusarium, Thielavia, Acremonium, Chrysosporium and
Trichoderma, especially those produced by a strain selected from
the species Aspergillus (see, e.g., EP Pub. No. 0 458 162),
Humicola insolens (reclassified as Scytalidium thermophilum, see,
e.g., U.S. Pat. No. 4,435,307), Coprinus cinereus, Fusarium
oxysporum, Myceliophthora thermophila, Meripilus giganteus,
Thielavia terrestris, Acremonium sp. (including, but not limited
to, A. persicinum, A. acremonium, A. brachypenium, A.
dichromosporum, A. obclavatum, A. pinkertoniae, A. roseogriseum, A.
incoloratum, and A. furatum). Preferred strains include Humicola
insolens DSM 1800, Fusarium oxysporum DSM 2672, Myceliophthora
thermophila CBS 117.65, Cephalosporium sp. RYM-202, Acremonium sp.
CBS 478.94, Acremonium sp. CBS 265.95, Acremonium persicinum CBS
169.65, Acremonium acremonium AHU 9519, Cephalosporium sp. CBS
535.71, Acremonium brachypenium CBS 866.73, Acremonium
dichromosporum CBS 683.73, Acremonium obclavatum CBS 311.74,
Acremonium pinkertoniae CBS 157.70, Acremonium roseogriseum CBS
134.56, Acremonium incoloratum CBS 146.62, and Acremonium furatum
CBS 299.70H. Cellulolytic enzymes may also be obtained from
Chrysosporium, preferably a strain of Chrysosporium lucknowense.
Additional strains that can be used include, but are not limited
to, Trichoderma (particularly T. viride, T. reesei, and T.
koningii), alkalophilic Bacillus (see, for example, U.S. Pat. No.
3,844,890 and EP Pub. No. 0 458 162), and Streptomyces (see, e.g.,
EP Pub. No. 0 458 162).
[0134] In addition to or in combination to enzymes, acids, bases
and other chemicals (e.g., oxidants) can be utilized to saccharify
lignocellulosic and cellulosic materials. These can be used in any
combination or sequence (e.g., before, after and/or during addition
of an enzyme). For example strong mineral acids can be utilized
(e.g. HCl, H.sub.2SO.sub.4, H.sub.3PO.sub.4) and strong bases
(e.g., NaOH, KOH).
Sugars
[0135] In the processes described herein, for example after
saccharification, sugars (e.g., glucose and xylose) can be
isolated. For example sugars can be isolated by precipitation,
crystallization, chromatography (e.g., simulated moving bed
chromatography, high pressure chromatography), centrifugation,
extraction, any other isolation method known in the art, and
combinations thereof.
Fermentation
[0136] Yeast and Zymomonas bacteria, for example, can be used for
fermentation or conversion of sugar(s) to alcohol(s). Other
microorganisms are discussed below. The optimum pH for
fermentations is about pH 4 to 7. For example, the optimum pH for
yeast is from about pH 4 to 5, while the optimum pH for Zymomonas
is from about pH 5 to 6. Typical fermentation times are about 24 to
168 hours (e.g., 24 to 96 hrs.) with temperatures in the range of
20.degree. C. to 40.degree. C. (e.g., 26.degree. C. to 40.degree.
C.), however thermophilic microorganisms prefer higher
temperatures.
[0137] In some embodiments, e.g., when anaerobic organisms are
used, at least a portion of the fermentation is conducted in the
absence of oxygen, e.g., under a blanket of an inert gas such as
N.sub.2, Ar, He, CO.sub.2 or mixtures thereof. Additionally, the
mixture may have a constant purge of an inert gas flowing through
the tank during part of or all of the fermentation. In some cases,
anaerobic condition, can be achieved or maintained by carbon
dioxide production during the fermentation and no additional inert
gas is needed.
[0138] In some embodiments, all or a portion of the fermentation
process can be interrupted before the low molecular weight sugar is
completely converted to a product (e.g., ethanol). The intermediate
fermentation products include sugar and carbohydrates in high
concentrations. The sugars and carbohydrates can be isolated via
any means known in the art. These intermediate fermentation
products can be used in preparation of food for human or animal
consumption. Additionally or alternatively, the intermediate
fermentation products can be ground to a fine particle size in a
stainless-steel laboratory mill to produce a flour-like substance.
Jet mixing may be used during fermentation, and in some cases
saccharification and fermentation are performed in the same
tank.
[0139] Nutrients for the microorganisms may be added during
saccharification and/or fermentation, for example the food-based
nutrient packages described in U.S. Pat. App. Pub. 2012/0052536,
filed Jul. 15, 2011, the complete disclosure of which is
incorporated herein by reference. In some cases, the food-based
nutrient source is selected from the group consisting of grains,
vegetables, residues of grains, residues of vegetables, residues of
meat (e.g., stock, extract, bouillon or renderings), and mixtures
thereof. For example, the nutrient source may be selected from the
group consisting of wheat, oats, barley, soybeans, peas, legumes,
potatoes, corn, rice bran, corn meal, wheat bran, meat product
residues, and mixtures thereof.
[0140] "Fermentation" includes the methods and products that are
disclosed in International App. No. PCT/US2012/071097 (which was
filed Dec. 20, 2012, was published in English as WO 2013/096700 and
designated the United States) and International App. No.
PCT/US2012/071083 (which was filed Dec. 20, 2012, was published in
English as WO 2013/096693 and designated the United States) the
contents of both of which are incorporated by reference herein in
their entirety.
[0141] Mobile fermenters can be utilized, as described in
International App. No. PCT/US2007/074028 (which was filed Jul. 20,
2007, was published in English as WO 2008/011598 and designated the
United States) and has a US issued U.S. Pat. No. 8,318,453, the
contents of which are incorporated herein in its entirety.
Similarly, the saccharification equipment can be mobile. Further,
saccharification and/or fermentation may be performed in part or
entirely during transit.
Fermentation Agents
[0142] The microorganism(s) used in fermentation can be
naturally-occurring microorganisms and/or engineered
microorganisms. For example, the microorganism can be a bacterium
(including, but not limited to, e.g., a cellulolytic bacterium), a
fungus, (including, but not limited to, e.g., a yeast), a plant, a
protist, e.g., a protozoa or a fungus-like protest (including, but
not limited to, e.g., a slime mold), or an alga. When the organisms
are compatible, mixtures of organisms can be utilized.
[0143] Suitable fermenting microorganisms have the ability to
convert carbohydrates, such as glucose, fructose, xylose,
arabinose, mannose, galactose, oligosaccharides or polysaccharides
into fermentation products. Fermenting microorganisms include
strains of the genus Saccharomyces spp. (including, but not limited
to, S. cerevisiae (baker's yeast), S. distaticus, S. uvarum), the
genus Kluyveromyces, (including, but not limited to, K. marxianus,
K. fragilis), the genus Candida (including, but not limited to, C.
pseudotropicalis, and C. brassicae), Pichia stipitis (a relative of
Candida shehatae), the genus Clavispora (including, but not limited
to, C. lusitaniae and C. opuntiae), the genus Pachysolen
(including, but not limited to, P. tannophilus), the genus
Bretannomyces (including, but not limited to, e.g., B. clausenii
(Philippidis, G. P., 1996, Cellulose bioconversion technology, in
Handbook on Bioethanol: Production and Utilization, Wyman, C. E.,
ed., Taylor & Francis, Washington, D.C., 179-212)). Other
suitable microorganisms include, for example, Zymomonas mobilis,
Clostridium spp. (including, but not limited to, C. thermocellum
(Philippidis, 1996, supra), C. saccharobutylacetonicum, C.
tyrobutyricum C. saccharobutylicum, C. Puniceum, C. beijernckii,
and C. acetobutylicum), Moniliella spp. (including but not limited
to M. pollinis, M. tomentosa, M. madida, M. nigrescens, M.
oedocephali, M. megachiliensis), Yarrowia lipolytica, Aureobasidium
sp., Trichosporonoides sp., Trigonopsis variabilis, Trichosporon
sp., Moniliellaacetoabutans sp., Typhula variabilis, Candida
magnoliae, Ustilaginomycetes sp., Pseudozyma tsukubaensis, yeast
species of genera Zygosaccharomyces, Debaryomyces, Hansenula and
Pichia, and fungi of the dematioid genus Torula (e.g., T.
corallina).
[0144] Additional microorganisms include the Lactobacillus group.
Examples include Lactobacillus casei, Lactobacillus rhamnosus,
Lactobacillus delbrueckii, Lactobacillus plantarum, Lactobacillus
coryniformis, e.g., Lactobacillus coryniformis subspecies torquens,
Lactobacillus pentosus, Lactobacillus brevis. Other microorganisms
include Pediococus penosaceus, Rhizopus oryzae.
[0145] Several organisms, such as bacteria, yeasts and fungi, can
be utilized to ferment biomass derived products such as sugars and
alcohols to succinic acid and similar products. For example,
organisms can be selected from; Actinobacillus succinogenes,
Anaerobiospirillum succiniciproducens, Mannheimia
succiniciproducens, Ruminococcus flaverfaciens, Ruminococcus albus,
Fibrobacter succinogenes, Bacteroides fragilis, Bacteroides
ruminicola, Bacteroides amylophilus, Bacteriodes succinogenes,
Mannheimia succiniciproducens, Corynebacterium glutamicum,
Aspergillus niger, Aspergillus fumigatus, Byssochlamys nivea,
Lentinus degener, Paecilomyces varioti, Penicillium viniferum,
Saccharomyces cerevisiae, Enterococcus faecali, Prevotella
ruminicolas, Debaryomyces hansenii, Candida catenulata VKM Y-5, C.
mycoderma. VKM Y-240, C. rugosa VKM Y-67, C. paludigena VKM Y-2443,
C. wills VKM Y-74, C. wills 766, C. zeylanoides VKM Y-6, C.
zeylanoides VKM Y-14, C. zeylanoides VKM Y-2324, C. zeylanoides VKM
Y-1543, C. zeylanoides VKM Y-2595, C. valida VKM Y-934,
Kluyveromyces wickerhamii VKM Y-589, Pichia anomala VKM Y-118, P.
besseyi VKM Y-2084, P. media VKM Y-1381, P. guilliermondii H-P-4,
P. guilliermondii 916, P. inositovora VKM Y-2494, Saccharomyces
cerevisiae VKM Y-381, Torulopsis candida 127, T. candida 420,
Yarrowia lipolytica 12a, Y. lipolytica VKM Y-47, Y. lipolytica 69,
Y. lipolytica VKM Y-57, Y. lipolytica 212, Y. lipolytica 374/4, Y.
lipolytica 585, Y. lipolytica 695, Y. lipolytica 704, and mixtures
of these organisms.
[0146] Many such microbial strains are publicly available, either
commercially or from depositories such as the ATCC (American Type
Culture Collection, Manassas, Va., USA), the NRRL (Agricultural
Research Service Culture Collection, Peoria, Ill., USA), or the
DSMZ (Deutsche Sammlung von Mikroorganismen and Zellkulturen GmbH,
Braunschweig, Germany), to name a few.
[0147] Commercially available yeasts include, for example, Red
Star.RTM./Lesaffre Ethanol Red (available from Red Star/Lesaffre,
USA), FALI.RTM. (available from Fleischmann's Yeast, a division of
Burns Philip Food Inc., USA), SUPERSTART.RTM. (Lallemand Biofuels
and Distilled Spirits, Canada), EAGLE C6 FUEL.TM. or C6 FUEL.TM.
(available from Lallemand Biofuels and Distilled Spirits, Canada),
GERT STRAND.RTM. (available from Gert Strand AB, Sweden) and
FERMOL.RTM. (available from DSM Specialties).
Distillation
[0148] After fermentation, the resulting fluids can be distilled
using, for example, a "beer column" to separate ethanol and other
alcohols from the majority of water and residual solids. The vapor
exiting the beer column can be, e.g., 35% by weight ethanol and can
be fed to a rectification column. A mixture of nearly azeotropic
(92.5%) ethanol and water from the rectification column can be
purified to pure (99.5%) ethanol using vapor-phase molecular
sieves. The beer column bottoms can be sent to the first effect of
a three-effect evaporator. The rectification column reflux
condenser can provide heat for this first effect. After the first
effect, solids can be separated using a centrifuge and dried in a
rotary dryer. A portion (25%) of the centrifuge effluent can be
recycled to fermentation and the rest sent to the second and third
evaporator effects. Most of the evaporator condensate can be
returned to the process as fairly clean condensate with a small
portion split off to waste water treatment to prevent build-up of
low-boiling compounds.
Hydrocarbon-Containing Materials
[0149] In other embodiments utilizing the methods and systems
described herein, hydrocarbon-containing materials can be
processed. Any process described herein can be used to treat any
hydrocarbon-containing material herein described.
"Hydrocarbon-containing materials," as used herein, is meant to
include oil sands, oil shale, tar sands, coal dust, coal slurry,
bitumen, various types of coal, and other naturally-occurring and
synthetic materials that include both hydrocarbon components and
solid matter. The solid matter can include rock, sand, clay, stone,
silt, drilling slurry, or other solid organic and/or inorganic
matter. The term can also include waste products such as drilling
waste and by-products, refining waste and by-products, or other
waste products containing hydrocarbon components, such as asphalt
shingling and covering, asphalt pavement, etc.
Conveying Systems
[0150] Various conveying systems can be used to convey the biomass
material, for example, to a vault and under an electron beam in a
vault. Exemplary conveyors are belt conveyors, pneumatic conveyors,
screw conveyors, carts, trains, trains or carts on rails,
elevators, front loaders, backhoes, cranes, various scrapers and
shovels, trucks, and throwing devices can be used. For example,
vibratory conveyors can be used in various processes described
herein, for example, as disclosed in US. Provisional Application
61/711,801 filed Oct. 10, 2012, the entire disclosure of which is
herein incorporated by reference.
Hydrogenation and Other Chemical Transformations
[0151] The processes described herein can include hydrogenation.
For example glucose and xylose can be hydrogenated to sorbitol and
xylitol respectively. Hydrogenation can be accomplished by use of a
catalyst (e.g., Pt/gamma-Al.sub.2O.sub.3, Ru/C, Raney Nickel, or
other catalysts know in the art) in combination with H.sub.2 under
high pressure (e.g., 10 to 12000 psi). Other types of chemical
transformation of the products from the processes described herein
can be used, for example production of organic sugar derived
products such (e.g., furfural and furfural-derived products).
Chemical transformations of sugar derived products are described in
U.S. Prov. App. No. 61/667,481, filed Jul. 3, 2012, the disclosure
of which is incorporated herein by reference in its entirety.
Lignin Derived Products
[0152] The spent biomass (e.g., spent lignocellulosic material)
from lignocellulosic processing by the methods described are
expected to have a high lignin content and in addition to being
useful for producing energy through combustion in a Co-Generation
plant, may have uses as other valuable products. For example, the
lignin can be used as captured as a plastic, or it can be
synthetically upgraded to other plastics. In some instances, it can
also be converted to lignosulfonates, which can be utilized as
binders, dispersants, emulsifiers or as sequestrants.
[0153] When used as a binder, the lignin or a lignosulfonate can,
e.g., be utilized in coal briquettes, in ceramics, for binding
carbon black, for binding fertilizers and herbicides, as a dust
suppressant, in the making of plywood and particle board, for
binding animal feeds, as a binder for fiberglass, as a binder in
linoleum paste and as a soil stabilizer.
[0154] As a dispersant, the lignin or lignosulfonates can be used,
e.g., concrete mixes, clay and ceramics, dyes and pigments, leather
tanning and in gypsum board.
[0155] As an emulsifier, the lignin or lignosulfonates can be used,
e.g., in asphalt, pigments and dyes, pesticides and wax
emulsions.
[0156] As a sequestrant, the lignin or lignosulfonates can be used,
e.g., in micro-nutrient systems, cleaning compounds and water
treatment systems, e.g., for boiler and cooling systems.
[0157] For energy production lignin generally has a higher energy
content than holocellulose (cellulose and hemicellulose) since it
contains more carbon than holocellulose. For example, dry lignin
can have an energy content of between about 11,000 and 12,500 BTU
per pound, compared to 7,000 an 8,000 BTU per pound of
holocellulose. As such, lignin can be densified and converted into
briquettes and pellets for burning. For example, the lignin can be
converted into pellets by any method described herein. For a slower
burning pellet or briquette, the lignin can be crosslinked, such as
applying a radiation dose of between about 0.5 Mrad and 5 Mrad.
Crosslinking can make a slower burning form factor. The form
factor, such as a pellet or briquette, can be converted to a
"synthetic coal" or charcoal by pyrolyzing in the absence of air,
e.g., at between 400 and 950.degree. C. Prior to pyrolyzing, it can
be desirable to crosslink the lignin to maintain structural
integrity.
[0158] Co-generation using spent biomass is described in U.S.
Provisional Application No. 61/774,773, filed Mar. 8, 2013, the
entire disclosure therein is herein incorporated by reference. The
spent biomass may be the lignin byproducts described above and/or
the fermentation solids from the first and/or the second
fermentation.
Other Embodiments
[0159] Any material, processes or processed materials described
herein can be used to make products and/or intermediates such as
composites, fillers, binders, plastic additives, adsorbents and
controlled release agents. The methods can include densification,
for example, by applying pressure and heat to the materials. For
example composites can be made by combining fibrous materials with
a resin or polymer. For example radiation cross-linkable resin,
e.g., a thermoplastic resin can be combined with a fibrous material
to provide a fibrous material/cross-linkable resin combination.
Such materials can be, for example, useful as building materials,
protective sheets, containers and other structural materials (e.g.,
molded and/or extruded products). Absorbents can be, for example,
in the form of pellets, chips, fibers and/or sheets. Adsorbents can
be used, for example, as pet bedding, packaging material or in
pollution control systems. Controlled release matrices can also be
the form of, for example, pellets, chips, fibers and or sheets. The
controlled release matrices can, for example, be used to release
drugs, biocides, fragrances. For example, composites, absorbents
and control release agents and their uses are described in U.S.
Serial No. PCT/US2006/010648, filed Mar. 23, 2006, and U.S. Pat.
No. 8,074,910 filed Nov. 22, 2011, the entire disclosures of which
are herein incorporated by reference.
[0160] In some instances the biomass material is treated at a first
level to reduce recalcitrance, e.g., utilizing accelerated
electrons, to selectively release one or more sugars (e.g.,
xylose). The biomass can then be treated to a second level to
release one or more other sugars (e.g., glucose). Optionally the
biomass can be dried between treatments. The treatments can include
applying chemical and biochemical treatments to release the sugars.
For example, a biomass material can be treated to a level of less
than about 20 Mrad (e.g., less than about 15 Mrad, less than about
10 Mrad, less than about 5 Mrad, less than about 2 Mrad) and then
treated with a solution of sulfuric acid, containing less than 10%
sulfuric acid (e.g., less than about 9%, less than about 8%, less
than about 7%, less than about 6%, less than about 5%, less than
about 4%, less than about 3%, less than about 2%, less than about
1%, less than about 0.75%, less than about 0.50%, less than about
0.25%) to release xylose. Xylose, for example that is released into
solution, can be separated from solids and optionally the solids
washed with a solvent/solution (e.g., with water and/or acidified
water). Optionally, the solids can be dried, for example in air
and/or under vacuum optionally with heating (e.g., below about 150
deg C, below about 120 deg C) to a water content below about 25 wt.
% (below about 20 wt. %, below about 15 wt. %, below about 10 wt.
%, below about 5 wt. %). The solids can then be treated with a
level of less than about 30 Mrad (e.g., less than about 25 Mrad,
less than about 20 Mrad, less than about 15 Mrad, less than about
10 Mrad, less than about 5 Mrad, less than about 1 Mrad or even not
at all) and then treated with an enzyme (e.g., a cellulase) to
release glucose. The glucose (e.g., glucose in solution) can be
separated from the remaining solids. The solids can then be further
processed, for example utilized to make energy or other products
(e.g., lignin derived products).
[0161] Other than in the examples herein, or unless otherwise
expressly specified, all of the numerical ranges, amounts, values
and percentages, such as those for amounts of materials, elemental
contents, times and temperatures of reaction, ratios of amounts,
and others, in the following portion of the specification and
attached claims may be read as if prefaced by the word "about" even
though the term "about" may not expressly appear with the value,
amount, or range. Accordingly, unless indicated to the contrary,
the numerical parameters set forth in the following specification
and attached claims are approximations that may vary depending upon
the desired properties sought to be obtained by the present
invention. At the very least, and not as an attempt to limit the
application of the doctrine of equivalents to the scope of the
claims, each numerical parameter should at least be construed in
light of the number of reported significant digits and by applying
ordinary rounding techniques.
Flavors, Fragrances and Colorants
[0162] Any of the products and/or intermediates described herein,
for example, produced by the processes, systems and/or equipment
described herein, can be combined with flavors, fragrances,
colorants and/or mixtures of these. For example, any one or more of
(optionally along with flavors, fragrances and/or colorants)
sugars, organic acids, fuels, polyols, such as sugar alcohols,
biomass, fibers and composites can be combined with (e.g.,
formulated, mixed or reacted) or used to make other products. For
example, one or more such product can be used to make soaps,
detergents, candies, drinks (e.g., cola, wine, beer, liquors such
as gin or vodka, sports drinks, coffees, teas), pharmaceuticals,
adhesives, sheets (e.g., woven, none woven, filters, tissues)
and/or composites (e.g., boards). For example, one or more such
product can be combined with herbs, flowers, petals, spices,
vitamins, potpourri, or candles. For example, the formulated, mixed
or reacted combinations can have flavors/fragrances of grapefruit,
orange, apple, raspberry, banana, lettuce, celery, cinnamon,
chocolate, vanilla, peppermint, mint, onion, garlic, pepper,
saffron, ginger, milk, wine, beer, tea, lean beef, fish, clams,
olive oil, coconut fat, pork fat, butter fat, beef bouillon,
legume, potatoes, marmalade, ham, coffee and cheeses.
[0163] Flavors, fragrances and colorants can be added in any
amount, such as between about 0.001 wt. % to about 30 wt. %, e.g.,
between about 0.01 to about 20, between about 0.05 to about 10, or
between about 0.1 wt. % to about 5 wt. %. These can be formulated,
mixed and or reacted (e.g., with any one of more product or
intermediate described herein) by any means and in any order or
sequence (e.g., agitated, mixed, emulsified, gelled, infused,
heated, sonicated, and/or suspended). Fillers, binders, emulsifier,
antioxidants can also be utilized, for example protein gels,
starches and silica.
[0164] In one embodiment the flavors, fragrances and colorants can
be added to the biomass immediately after the biomass is irradiated
such that the reactive sites created by the irradiation may react
with reactive compatible sites of the flavors, fragrances, and
colorants.
[0165] The flavors, fragrances and colorants can be natural and/or
synthetic materials. These materials can be one or more of a
compound, a composition or mixtures of these (e.g., a formulated or
natural composition of several compounds). Optionally the flavors,
fragrances, antioxidants and colorants can be derived biologically,
for example, from a fermentation process (e.g., fermentation of
saccharified materials as described herein). Alternatively, or
additionally these flavors, fragrances and colorants can be
harvested from a whole organism (e.g., plant, fungus, animal,
bacteria or yeast) or a part of an organism. The organism can be
collected and or extracted to provide color, flavors, fragrances
and/or antioxidant by any means including utilizing the methods,
systems and equipment described herein, hot water extraction,
supercritical fluid extraction, chemical extraction (e.g., solvent
or reactive extraction including acids and bases), mechanical
extraction (e.g., pressing, comminuting, filtering), utilizing an
enzyme, utilizing a bacteria such as to break down a starting
material, and combinations of these methods. The compounds can be
derived by a chemical reaction, for example, the combination of a
sugar (e.g., as produced as described herein) with an amino acid
(Maillard reaction). The flavor, fragrance, antioxidant and/or
colorant can be an intermediate and or product produced by the
methods, equipment or systems described herein, for example and
ester and a lignin derived product.
[0166] Some examples of flavor, fragrances or colorants are
polyphenols. Polyphenols are pigments responsible for the red,
purple and blue colorants of many fruits, vegetables, cereal
grains, and flowers. Polyphenols also can have antioxidant
properties and often have a bitter taste. The antioxidant
properties make these important preservatives. On class of
polyphenols are the flavonoids, such as Anthocyanidines,
flavanonols, flavan-3-ols, s, flavanones and flavanonols. Other
phenolic compounds that can be used include phenolic acids and
their esters, such as chlorogenic acid and polymeric tannins.
[0167] Among the colorants inorganic compounds, minerals or organic
compounds can be used, for example titanium dioxide, zinc oxide,
aluminum oxide, cadmium yellow (E.g., CdS), cadmium orange (e.g.,
CdS with some Se), alizarin crimson (e.g., synthetic or
non-synthetic rose madder), ultramarine (e.g., synthetic
ultramarine, natural ultramarine, synthetic ultramarine violet),
cobalt blue, cobalt yellow, cobalt green, viridian (e.g., hydrated
chromium(III)oxide), chalcophylite, conichalcite, cornubite,
cornwallite and liroconite. Black pigments such as carbon black and
self-dispersed blacks may be used.
[0168] Some flavors and fragrances that can be utilized include
ACALEA TBHQ, ACET C-6, ALLYL AMYL GLYCOLATE, ALPHA TERPINEOL,
AMBRETTOLIDE, AMBRINOL 95, ANDRANE, APHERMATE, APPLELIDE,
BACDANOL.RTM., BERGAMAL, BETA IONONE EPDXIDE, BETA NAPHTHYL
ISO-BUTYL ETHER, BICYCLONONALACTONE, BORNAFIX.RTM., CANTHOXAL,
CASHMERAN.RTM., CASHMERAN.RTM. VELVET, CASSIFFIX.RTM., CEDRAFIX,
CEDRAMBER.RTM., CEDRYL ACETATE, CELESTOLIDE, CINNAMALVA, CITRAL
DIMETHYL ACETATE, CITROLATE.TM., CITRONELLOL 700, CITRONELLOL 950,
CITRONELLOL COEUR, CITRONELLYL ACETATE, CITRONELLYL ACETATE PURE,
CITRONELLYL FORMATE, CLARYCET, CLONAL, CONIFERAN, CONIFERAN PURE,
CORTEX ALDEHYDE 50% PEOMOSA, CYCLABUTE, CYCLACET.RTM.,
CYCLAPROP.RTM., CYCLEMAX.TM., CYCLOHEXYL ETHYL ACETATE, DAMASCOL,
DELTA DAMASCONE, DIHYDRO CYCLACET, DIHYDRO MYRCENOL, DIHYDRO
TERPINEOL, DIHYDRO TERPINYL ACETATE, DIMETHYL CYCLORMOL, DIMETHYL
OCTANOL PQ, DIMYRCETOL, DIOLA, DIPENTENE, DULCINYL.RTM.
RECRYSTALLIZED, ETHYL-3-PHENYL GLYCIDATE, FLEURAMONE, FLEURANIL,
FLORAL SUPER, FLORALOZONE, FLORIFFOL, FRAISTONE, FRUCTONE,
GALAXOLIDE.RTM. 50, GALAXOLIDE.RTM. 50 BB, GALAXOLIDE.RTM. 50 IPM,
GALAXOLIDE.RTM. UNDILUTED, GALBASCONE, GERALDEHYDE, GERANIOL 5020,
GERANIOL 600 TYPE, GERANIOL 950, GERANIOL 980 (PURE), GERANIOL CFT
COEUR, GERANIOL COEUR, GERANYL ACETATE COEUR, GERANYL ACETATE,
PURE, GERANYL FORMATE, GRISALVA, GUAIYL ACETATE, HELIONAL.TM.,
HERBAC, HERBALIME.TM., HEXADECANOLIDE, HEXALON, HEXENYL SALICYLATE
CIS 3-, HYACINTH BODY, HYACINTH BODY NO. 3, HYDRATROPIC
ALDEHYDE.DMA, HYDROXYOL, INDOLAROME, INTRELEVEN ALDEHYDE,
INTRELEVEN ALDEHYDE SPECIAL, IONONE ALPHA, IONONE BETA, ISO CYCLO
CITRAL, ISO CYCLO GERANIOL, ISO E SUPER.RTM., ISOBUTYL QUINOLINE,
JASMAL, JESSEMAL.RTM., KHARISMAL.RTM., KHARISMAL.RTM. SUPER,
KHUSINIL, KOAVONE.RTM., KOHINOOL.RTM., LIFFAROME.TM., LIMOXAL,
LINDENOL.TM., LYRAL.RTM., LYRAME SUPER, MANDARIN ALD 10% TRI ETH,
CITR, MARITIMA, MCK CHINESE, MEIJIFF.TM., MELAFLEUR, MELOZONE,
METHYL ANTHRANILATE, METHYL IONONE ALPHA EXTRA, METHYL IONONE GAMMA
A, METHYL IONONE GAMMA COEUR, METHYL IONONE GAMMA PURE, METHYL
LAVENDER KETONE, MONTAVERDI.RTM., MUGUESIA, MUGUET ALDEHYDE 50,
MUSK Z4, MYRAC ALDEHYDE, MYRCENYL ACETATE, NECTARATE.TM., NEROL
900, NERYL ACETATE, OCIMENE, OCTACETAL, ORANGE FLOWER ETHER,
ORIVONE, ORRINIFF 25%, OXASPIRANE, OZOFLEUR, PAMPLEFLEUR.RTM.,
PEOMOSA, PHENOXANOL.RTM., PICONIA, PRECYCLEMONE B, PRENYL ACETATE,
PRISMANTOL, RESEDA BODY, ROSALVA, ROSAMUSK, SANJINOL,
SANTALIFF.TM., SYVERTAL, TERPINEOL, TERPINOLENE 20, TERPINOLENE 90
PQ, TERPINOLENE RECT., TERPINYL ACETATE, TERPINYL ACETATE JAX,
TETRAHYDRO, MUGUOL.RTM., TETRAHYDRO MYRCENOL, TETRAMERAN,
TIMBERSILK.TM., TOBACAROL, TRIMOFIX.RTM. O TT, TRIPLAL.RTM.,
TRISAMBER.RTM., VANORIS, VERDOX.TM. VERDOX.TM. HC, VERTENEX.RTM.,
VERTENEX.RTM. HC, VERTOFIX.RTM. COEUR, VERTOLIFF, VERTOLIFF ISO,
VIOLIFF, VIVALDIE, ZENOLIDE, ABS INDIA 75 PCT MIGLYOL, ABS MOROCCO
50 PCT DPG, ABS MOROCCO 50 PCT TEC, ABSOLUTE FRENCH, ABSOLUTE
INDIA, ABSOLUTE MD 50 PCT BB, ABSOLUTE MOROCCO, CONCENTRATE PG,
TINCTURE 20 PCT, AMBERGRIS, AMBRETTE ABSOLUTE, AMBRETTE SEED OIL,
ARMOISE OIL 70 PCT THUYONE, BASIL ABSOLUTE GRAND VERT, BASIL GRAND
VERT ABS MD, BASIL OIL GRAND VERT, BASIL OIL VERVEINA, BASIL OIL
VIETNAM, BAY OIL TERPENELESS, BEESWAX ABS N G, BEESWAX ABSOLUTE,
BENZOIN RESINOID SIAM, BENZOIN RESINOID SIAM 50 PCT DPG, BENZOIN
RESINOID SIAM 50 PCT PG, BENZOIN RESINOID SIAM 70.5 PCT TEC,
BLACKCURRANT BUD ABS 65 PCT PG, BLACKCURRANT BUD ABS MD 37 PCT TEC,
BLACKCURRANT BUD ABS MIGLYOL, BLACKCURRANT BUD ABSOLUTE BURGUNDY,
BOIS DE ROSE OIL, BRAN ABSOLUTE, BRAN RESINOID, BROOM ABSOLUTE
ITALY, CARDAMOM GUATEMALA CO2 EXTRACT, CARDAMOM OIL GUATEMALA,
CARDAMOM OIL INDIA, CARROT HEART, CASSIE ABSOLUTE EGYPT, CASSIE
ABSOLUTE MD 50 PCT IPM, CASTOREUM ABS 90 PCT TEC, CASTOREUM ABS C
50 PCT MIGLYOL, CASTOREUM ABSOLUTE, CASTOREUM RESINOID, CASTOREUM
RESINOID 50 PCT DPG, CEDROL CEDRENE, CEDRUS ATLANTICA OIL REDIST,
CHAMOMILE OIL ROMAN, CHAMOMILE OIL WILD, CHAMOMILE OIL WILD LOW
LIMONENE, CINNAMON BARK OIL CEYLAN, CISTE ABSOLUTE, CISTE ABSOLUTE
COLORLESS, CITRONELLA OIL ASIA IRON FREE, CIVET ABS 75 PCT PG,
CIVET ABSOLUTE, CIVET TINCTURE 10 PCT, CLARY SAGE ABS FRENCH DECOL,
CLARY SAGE ABSOLUTE FRENCH, CLARY SAGE C'LESS 50 PCT PG, CLARY SAGE
OIL FRENCH, COPAIBA BALSAM, COPAIBA BALSAM OIL, CORIANDER SEED OIL,
CYPRESS OIL, CYPRESS OIL ORGANIC, DAVANA OIL, GALBANOL, GALBANUM
ABSOLUTE COLORLESS, GALBANUM OIL, GALBANUM RESINOID, GALBANUM
RESINOID 50 PCT DPG, GALBANUM RESINOID HERCOLYN BHT, GALBANUM
RESINOID TEC BHT, GENTIANE ABSOLUTE MD 20 PCT BB, GENTIANE
CONCRETE, GERANIUM ABS EGYPT MD, GERANIUM ABSOLUTE EGYPT, GERANIUM
OIL CHINA, GERANIUM OIL EGYPT, GINGER OIL 624, GINGER OIL RECTIFIED
SOLUBLE, GUAIACWOOD HEART, HAY ABS MD 50 PCT BB, HAY ABSOLUTE, HAY
ABSOLUTE MD 50 PCT TEC, HEALINGWOOD, HYSSOP OIL ORGANIC, IMMORTELLE
ABS YUGO MD 50 PCT TEC, IMMORTELLE ABSOLUTE SPAIN, IMMORTELLE
ABSOLUTE YUGO, JASMIN ABS INDIA MD, JASMIN ABSOLUTE EGYPT, JASMIN
ABSOLUTE INDIA, ASMIN ABSOLUTE MOROCCO, JASMIN ABSOLUTE SAMBAC,
JONQUILLE ABS MD 20 PCT BB, JONQUILLE ABSOLUTE France, JUNIPER
BERRY OIL FLG, JUNIPER BERRY OIL RECTIFIED SOLUBLE, LABDANUM
RESINOID 50 PCT TEC, LABDANUM RESINOID BB, LABDANUM RESINOID MD,
LABDANUM RESINOID MD 50 PCT BB, LAVANDIN ABSOLUTE H, LAVANDIN
ABSOLUTE MD, LAVANDIN OIL ABRIAL ORGANIC, LAVANDIN OIL GROSSO
ORGANIC, LAVANDIN OIL SUPER, LAVENDER ABSOLUTE H, LAVENDER ABSOLUTE
MD, LAVENDER OIL COUMARIN FREE, LAVENDER OIL COUMARIN FREE ORGANIC,
LAVENDER OIL MAILLETTE ORGANIC, LAVENDER OIL MT, MACE ABSOLUTE BB,
MAGNOLIA FLOWER OIL LOW METHYL EUGENOL, MAGNOLIA FLOWER OIL,
MAGNOLIA FLOWER OIL MD, MAGNOLIA LEAF OIL, MANDARIN OIL MD,
MANDARIN OIL MD BHT, MATE ABSOLUTE BB, MOSS TREE ABSOLUTE MD TEX
II-RA 43, MOSS-OAK ABS MD TEC IFRA 43, MOSS-OAK ABSOLUTE IFRA 43,
MOSS-TREE ABSOLUTE MD IPM IFRA 43, MYRRH RESINOID BB, MYRRH
RESINOID MD, MYRRH RESINOID TEC, MYRTLE OIL IRON FREE, MYRTLE OIL
TUNISIA RECTIFIED, NARCISSE ABS MD 20 PCT BB, NARCISSE ABSOLUTE
FRENCH, NEROLI OIL TUNISIA, NUTMEG OIL TERPENELESS, OEILLET
ABSOLUTE, OLIBANUM RESINOID, OLIBANUM RESINOID BB, OLIBANUM
RESINOID DPG, OLIBANUM RESINOID EXTRA 50 PCT DPG, OLIBANUM RESINOID
MD, OLIBANUM RESINOID MD 50 PCT DPG, OLIBANUM RESINOID TEC,
OPOPONAX RESINOID TEC, ORANGE BIGARADE OIL MD BHT, ORANGE BIGARADE
OIL MD SCFC, ORANGE FLOWER ABSOLUTE TUNISIA, ORANGE FLOWER WATER
ABSOLUTE TUNISIA, ORANGE LEAF ABSOLUTE, ORANGE LEAF WATER ABSOLUTE
TUNISIA, ORRIS ABSOLUTE ITALY, ORRIS CONCRETE 15 PCT IRONE, ORRIS
CONCRETE 8 PCT IRONE, ORRIS NATURAL 15 PCT IRONE 4095C, ORRIS
NATURAL 8 PCT IRONE 2942C, ORRIS RESINOID, OSMANTHUS ABSOLUTE,
OSMANTHUS ABSOLUTE MD 50 PCT BB, PATCHOULI HEART N.sup.o 3,
PATCHOULI OIL INDONESIA, PATCHOULI OIL INDONESIA IRON FREE,
PATCHOULI OIL INDONESIA MD, PATCHOULI OIL REDIST, PENNYROYAL HEART,
PEPPERMINT ABSOLUTE MD, PETITGRAIN BIGARADE OIL TUNISIA, PETITGRAIN
CITRONNIER OIL, PETITGRAIN OIL PARAGUAY TERPENELESS, PETITGRAIN OIL
TERPENELESS STAB, PIMENTO BERRY OIL, PIMENTO LEAF OIL, RHODINOL EX
GERANIUM CHINA, ROSE ABS BULGARIAN LOW METHYL EUGENOL, ROSE ABS
MOROCCO LOW METHYL EUGENOL, ROSE ABS TURKISH LOW METHYL EUGENOL,
ROSE ABSOLUTE, ROSE ABSOLUTE BULGARIAN, ROSE ABSOLUTE DAMASCENA,
ROSE ABSOLUTE MD, ROSE ABSOLUTE MOROCCO, ROSE ABSOLUTE TURKISH,
ROSE OIL BULGARIAN, ROSE OIL DAMASCENA LOW METHYL EUGENOL, ROSE OIL
TURKISH, ROSEMARY OIL CAMPHOR ORGANIC, ROSEMARY OIL TUNISIA,
SANDALWOOD OIL INDIA, SANDALWOOD OIL INDIA RECTIFIED, SANTALOL,
SCHINUS MOLLE OIL, ST JOHN BREAD TINCTURE 10 PCT, STYRAX RESINOID,
STYRAX RESINOID, TAGETE OIL, TEA TREE HEART, TONKA BEAN ABS 50 PCT
SOLVENTS, TONKA BEAN ABSOLUTE, TUBEROSE ABSOLUTE INDIA, VETIVER
HEART EXTRA, VETIVER OIL HAITI, VETIVER OIL HAITI MD, VETIVER OIL
JAVA, VETIVER OIL JAVA MD, VIOLET LEAF ABSOLUTE EGYPT, VIOLET LEAF
ABSOLUTE EGYPT DECOL, VIOLET LEAF ABSOLUTE FRENCH, VIOLET LEAF
ABSOLUTE MD 50 PCT BB, WORMWOOD OIL TERPENELESS, YLANG EXTRA OIL,
YLANG III OIL and combinations of these.
[0169] The colorants can be among those listed in the Colour Index
International by the Society of Dyers and Colourists. Colorants
include dyes and pigments and include those commonly used for
coloring textiles, paints, inks and inkjet inks. Some colorants
that can be utilized include carotenoids, arylide yellows,
diarylide yellows, .beta.-naphthols, naphthols, benzimidazolones,
disazo condensation pigments, pyrazolones, nickel azo yellow,
phthalocyanines, quinacridones, perylenes and perinones,
isoindolinone and isoindoline pigments, triarylcarbonium pigments,
diketopyrrolo-pyrrole pigments, thioindigoids. Cartenoids include
e.g., alpha-carotene, beta-carotene, gamma-carotene, lycopene,
lutein and astaxanthinAnnatto extract, Dehydrated beets (beet
powder), Canthaxanthin, Caramel, .beta.-Apo-8'-carotenal, Cochineal
extract, Carmine, Sodium copper chlorophyllin, Toasted partially
defatted cooked cottonseed flour, Ferrous gluconate, Ferrous
lactate, Grape color extract, Grape skin extract (enocianina),
Carrot oil, Paprika, Paprika oleoresin, Mica-based pearlescent
pigments, Riboflavin, Saffron, Titanium dioxide, Tomato lycopene
extract; tomato lycopene concentrate, Turmeric, Turmeric oleoresin,
FD&C Blue No. 1, FD&C Blue No. 2, FD&C Green No. 3,
Orange B, Citrus Red No. 2, FD&C Red No. 3, FD&C Red No.
40, FD&C Yellow No. 5, FD&C Yellow No. 6, Alumina (dried
aluminum hydroxide), Calcium carbonate, Potassium sodium copper
chlorophyllin (chlorophyllin-copper complex), Dihydroxyacetone,
Bismuth oxychloride, Ferric ammonium ferrocyanide, Ferric
ferrocyanide, Chromium hydroxide green, Chromium oxide greens,
Guanine, Pyrophyllite, Talc, Aluminum powder, Bronze powder, Copper
powder, Zinc oxide, D&C Blue No. 4, D&C Green No. 5,
D&C Green No. 6, D&C Green No. 8, D&C Orange No. 4,
D&C Orange No. 5, D&C Orange No. 10, D&C Orange No. 11,
FD&C Red No. 4, D&C Red No. 6, D&C Red No. 7, D&C
Red No. 17, D&C Red No. 21, D&C Red No. 22, D&C Red No.
27, D&C Red No. 28, D&C Red No. 30, D&C Red No. 31,
D&C Red No. 33, D&C Red No. 34, D&C Red No. 36, D&C
Red No. 39, D&C Violet No. 2, D&C Yellow No. 7, Ext.
D&C Yellow No. 7, D&C Yellow No. 8, D&C Yellow No. 10,
D&C Yellow No. 11, D&C Black No. 2, D&C Black No. 3
(3), D&C Brown No. 1, Ext. D&C, Chromium-cobalt-aluminum
oxide, Ferric ammonium citrate, Pyrogallol, Logwood extract,
1,4-Bis[(2-hydroxy-ethyl)amino]-9,10-anthracenedione
bis(2-propenoic)ester copolymers,
1,4-Bis[(2-methylphenyl)amino]-9,10-anthracenedione,
1,4-Bis[4-(2-methacryloxyethyl)phenylamino]anthraquinone
copolymers, Carbazole violet, Chlorophyllin-copper complex,
Chromium-cobalt-aluminum oxide, C.I. Vat Orange 1,
2-[[2,5-Diethoxy-4-[(4-methylphenyl)thiol]phenyl]azo]-1,3,5-benzenetriol,
16,23-Dihydrodinaphtho[2,3-a:2',3'-i]naphth[2',3':6,7]indolo[2,3-c]carbaz-
ole-5,10,15,17,22,24-hexone,
N,N'-(9,10-Dihydro-9,10-dioxo-1,5-anthracenediyl)bisbenzamide,
7,16-Dichloro-6,15-dihydro-5,9,14,18-anthrazinetetrone,
16,17-Dimethoxydinaphtho (1,2,3-cd:3',2',1'-lm)
perylene-5,10-dione, Poly(hydroxyethyl methacrylate)-dye
copolymers(3), Reactive Black 5, Reactive Blue 21, Reactive Orange
78, Reactive Yellow 15, Reactive Blue No. 19, Reactive Blue No. 4,
C.I. Reactive Red 11, C.I. Reactive Yellow 86, C.I. Reactive Blue
163, C.I. Reactive Red 180,
4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-on-
e (solvent Yellow 18),
6-Ethoxy-2-(6-ethoxy-3-oxobenzo[b]thien-2(3H)-ylidene)benzo[b]thiophen-3(-
2H)-one, Phthalocyanine green, Vinyl alcohol/methyl
methacrylate-dye reaction products, C.I. Reactive Red 180, C.I.
Reactive Black 5, C.I. Reactive Orange 78, C.I. Reactive Yellow 15,
C.I. Reactive Blue 21, Disodium
1-amino-4-[[4-[(2-bromo-1-oxoally)amino]-2-sulphonatophenyl]amin-
o]-9,10-dihydro-9,10-dioxoanthracene-2-sulphonate (Reactive Blue
69), D&C Blue No. 9, [Phthalocyaninato(2-)]copper and mixtures
of these.
Examples
[0170] Concentrations were determined by HPLC in aqueous diluted
and filtered solutions with appropriate standards. Unless otherwise
noted the reactants were obtained from Sigma/Aldrich, St. Louis
Mo., Fisher Scientific, Waltham Mass. or equivalent reactant supply
house.
Saccharification
[0171] A cylindrical tank with a diameter of 32 Inches, 64 Inches
in height and fit with ASME dished heads (top and bottom) was used
in the saccharification. The tank was also equipped with a
hydrofoil mixing blade 16'' wide. Heating was provided by flowing
hot water through a half pipe jacket surrounding the tank.
[0172] The tank was charged with 200 kg water, 80 kg of biomass,
and 18 kg of Duet.TM. Cellulase enzyme available from Genencor,
Palo Alto, Calif. Biomass was corn cob that had been hammer milled
and screened to a size of between 10 and 40 mesh. The biomass was
irradiated with an electron beam to a total dosage of 35 Mrad. The
pH of the mixture was adjusted and maintained automatically
throughout the saccharification at 4.8 using Ca(OH).sub.2. This
combination was heated to 53.degree. C., stirred at 180 rpm for
about 24 hours after which the saccharification was considered
completed.
[0173] A portion of this material was screened through a 20 mesh
screen and the solution stored in an 8 gal carboy at 4.degree.
C.
Fermentation of Glucose to Ethanol
[0174] About 400 mL of the saccharified material was decanted into
a 1 L New Brunswick BioFlow 115 Bioreactor. The material was
aerated and heated to 30.degree. C. prior to inoculation. Stirring
was set at 50 rpm. The pH was measured at 5.2, which is acceptable
for fermentation so it was not adjusted. Aeration was discontinued
and the contents of the bioreactor were inoculated with 5 mg of
Thermosacc Dry Yeast (Lallemand, Inc., Memphis Tenn.)
(Saccharomyces cerevisiae). Fermentation was allowed to proceed for
about 24 hours.
[0175] After fermentation the glucose concentration was below the
detection limit, the ethanol concentration was about 25 g/L, and
the xylose concentration was about 30 g/L.
Preparation of Distillate Bottoms
[0176] Distillate bottoms were prepared by distilling the ethanol
from fermented material as described above. In addition, solids
were removed by centrifugation. The final amount of dissolved
solids was 5 to 10 wt. There also were fines in the suspended
solid. After the distillation the xylose concentration was about 40
g/L. These bottoms were designated as Distillate Bottoms Lot A. A
similarly prepared batch was designated as Lot R.
Fermentation of Xylose to Butyric Acid:
[0177] Distillate Bottoms Experiment (A)
[0178] Seven 1 L New Brunswick BioFlow 115 Bioreactor were utilized
in the experiment. All seven reactors were initially filled with
200 mL of 3.times. concentrate of P2 media (described below) and of
72 g Xylose (Danisco, Copenhagen, DE). Two of the reactors (BR2 and
BR4) were charged with 120 mL of distillate bottom prepared as
described above (Lot A). Two reactors (BR6 and BR8) were charged
with 240 mL of distillate bottom (Lot A). Two (BR18 and BR20) were
charged with 360 mL of distillate bottom (Lot A). One reactor
(BR22) was charged with 240 mL of distillate bottom (Lot R). All
the bioreactors were brought to total volume of 600 mL with DI
water. For example, BR2 had 200 mL of P2 media, 120 mL of
Distillate Bottoms Lot A, .about.72 grams of xylose and DI water to
make up to 600 mL. The Xylose concentration was 72 grams plus
.about.4.8 g from the Distillate Bottoms for a concentration of
about 128 g/L. The reactors were sparged with N.sub.2 gas and
inoculated with 7% (45 mL of C. tyrobutyricum (ATCC 25755). The
seed was grown overnight at 37.degree. C. in 300 mL of reinforced
clostridia media from 1 mL freezer stocks. The bioreactors were
sampled periodically submitted for GC and HPLC analysis. The
fermentations were maintained above 6.0 using 3.7N ammonium
hydroxide. Table 1 shows data collected for these experiments.
[0179] P2 based medium was made as described in U.S. Pat. No.
6,358,717 but as a 3 fold concentrate (3.lamda.), that is only 1/3
of the water was used to make the solutions. P2 medium is made as
follows. The medium is composed of the following separately
prepared solutions (in grams per 100 ml of distilled water, unless
indicated otherwise): 790 ml of distilled water (solution I), 0.5 g
of K.sub.2HPO.sub.4, 0.5 g of KH.sub.2PO.sub.4, 2.2 g of
CH.sub.3COONH.sub.4 (solution II), 2.0 g of MgSO.sub.4.7H.sub.2O,
0.1 g of MnSO.sub.4--H.sub.2O, 0.1 g of NaCl, 0.1 g of
FeSO.sub.4.7H.sub.2O (solution III), and 100 mg of p-aminobenzoic
acid, 100 mg of thiamine, 1 mg of biotin (solution IV). Solutions I
and II were filter sterilized and subsequently mixed to form a
buffer solution. Solutions III and IV were filter sterilized.
Portions (10 and 1 ml) of solutions III and IV, respectively, were
added aseptically to the buffer solution. The final pH of the P2
medium was 6.6.
TABLE-US-00002 TABLE 1 Time Distillate Butyric Acid Xylose Sample
(hr.) bottom (g/L) (g/L) A-BR2 17 20% Lot A 8.5 95.1 A-BR4 17 20%
Lot A 9.7 93.4 A-BR6 17 40% Lot A 7.9 90.4 A-BR8 17 40% Lot A 4.9
106.4 A-BR18 17 60% Lot A 4.8 94.8 A-BR20 17 60% Lot A 5.5 94.6
A-BR22 17 60% Lot R 7.8 115.4 A-BR2 24 20% Lot A 15.6 81.4 A-BR4 24
20% Lot A 16.3 79.1 A-BR6 24 40% Lot A 16.3 78.9 A-BR8 24 40% Lot A
8 91.5 A-BR18 24 60% Lot A 9.5 83.8 A-BR20 24 60% Lot A 11.2 81.9
A-BR22 24 60% Lot R 12.7 102 A-BR2 41 20% Lot A 29.6 40.4 A-BR4 41
20% Lot A 30.8 35.1 A-BR6 41 40% Lot A 31.3 44.4 A-BR8 41 40% Lot A
20.9 55.8 A-BR18 41 60% Lot A 27 54.5 A-BR20 41 60% Lot A 27.6 52.2
A-BR22 41 60% Lot R 28.7 60.9 A-BR2 48 20% Lot A 34 28.5 A-BR4 48
20% Lot A 36 22.4 A-BR6 48 40% Lot A 34.7 35.7 A-BR8 48 40% Lot A
27.5 44.8 A-BR18 48 60% Lot A 32.7 46.9 A-BR20 48 60% Lot A 33.2
44.6 A-BR22 48 60% Lot R 30.8 48.7 A-BR2 66 20% Lot A 48 5.6 A-BR4
66 20% Lot A 48.1 0.5 A-BR6 66 40% Lot A 39.1 19.1 A-BR8 66 40% Lot
A 36.4 23.1 A-BR18 66 60% Lot A 38.1 28.7 A-BR20 66 60% Lot A 36.1
27.7 A-BR22 66 60% Lot R 38.1 25.2 A-BR2 72 20% Lot A 43.5 1.8
A-BR4 72 20% Lot A 42.8 NF A-BR6 72 40% Lot A 41.3 14.9 A-BR8 72
40% Lot A 41 16.4 A-BR18 72 60% Lot A 39.3 23.6 A-BR20 72 60% Lot A
39 23.1 A-BR22 72 60% Lot R 48.9 18.2 A-BR2 138 20% Lot A 47.4 NF
A-BR4 138 20% Lot A 43.2 NF A-BR6 138 40% Lot A 49 2.1 A-BR8 138
40% Lot A 46.1 0.5 A-BR18 138 60% Lot A 48.4 3 A-BR20 138 60% Lot A
47.5 3.9 A-BR22 138 60% Lot R 47.9 0.7 NF: not found, below
detection limit
[0180] Distillate Bottoms Experiment (B)
[0181] Six bioreactors were used in this experiment. For a 600 mL
reactor charge, two reactors (B-BR2 and B-BR4) were filled with 72
g of xylose, 5 ppm FeSO.sub.4x7H.sub.2O, and 6 g/L Fluka brand
yeast extract and DI water added to obtain 600 mL. Two other
reactors (B-BR6 and B-BR8) were filled with 72 g of xylose, 5 ppm
FeSO.sub.4x7H.sub.2O, 40%240 mL distillate bottom and DI water
added to obtain 600 mL. One reactor (B-BR 18) was filled with 72 g
xylose. 200 mL of modified P2 supplemented with 240 mL distillate
bottom and DI water added to obtain 600 mL. Another reactor
(B-BR20) was filled with 72 g of xylose, 200 mL of modified P2
supplemented (as described above, but not as the 3.times.
concentrate) with 60 g/L yeast extract and DI water added to obtain
600 mL. All six reactors were sparged with N.sub.2 gas and then
inoculated with 5% (30 ml) of C. tyrobutyricum (ATCC 25755)). Table
2 shows this data.
[0182] The seed was grown overnight in a modified reinforced
clostridia media consisting per liter of 10 g peptone, 10 g beef
extract, 5 g NaCl, 0.5 g of L cysteine, 3 g of sodium acetate, 0.5
g of anhydrous agar and 5 g of xylose. The media was made up in 900
ml of di water without xylose; 270 ml was aliquoted into 500 ml
bottles. The bottles were sparged, autoclaved, and 30 ml of 50 g/L
xylose was injected through a 0.22 micron filter into each bottle.
The xylose solution was sparged with N.sub.2 gas prior to
injection. A 1 ml freezer stock was used per 300 ml bottle.
[0183] The pH of the fermentation was maintained above 6.0 using
3.7N NH.sub.4OH. Samples were taken periodically and analyzed with
GC and HPLC.
TABLE-US-00003 TABLE 2 Butyric Acid Xylose Sample Time (hr.) Media
(g/L) (g/L) B-BR2 17 6 g/L YE + 5 mg/L FeSO.sub.4 NF 94 B-BR4 17 6
g/L YE + 5 mg/L FeSO.sub.4 NF 95.4 B-BR6 17 40% DB + 5 mg/L
FeSO.sub.4 NF 117.8 B-BR8 17 40% DB + 5 mg/L FeSO.sub.4 NF 119.2 B-
17 P2 + 40% DB 0.3 104.4 BR18 B- 17 P2 + 60 g/L YE NF 98.2 BR20
B-BR2 24 6 g/L YE + 5 mg/L FeSO.sub.4 0.8 84.4 B-BR4 24 6 g/L YE +
5 mg/L FeSO.sub.4 1.2 83.1 B-BR6 24 40% DB + 5 mg/L FeSO.sub.4 0.8
113.2 B-BR8 24 40% DB + 5 mg/L FeSO.sub.4 0.7 113 B- 24 P2 + 40% DB
0.9 101 BR18 B- 24 P2 + 60 g/L YE 1.7 99 BR20 B-BR2 41 6 g/L YE + 5
mg/L FeSO.sub.4 5.5 51.9 B-BR4 41 6 g/L YE + 5 mg/L FeSO.sub.4 9.3
48.5 B-BR6 41 40% DB + 5 mg/L FeSO.sub.4 14.8 88 B-BR8 41 40% DB +
5 mg/L FeSO.sub.4 14 91.4 B- 41 P2 + 40% DB 7.9 73.7 BR18 B- 41 P2
+ 60 g/L YE 32.5 3.8 BR20 B-BR2 48 6 g/L YE + 5 mg/L FeSO.sub.4 7.1
44.1 B-BR4 48 6 g/L YE + 5 mg/L FeSO.sub.4 11 41.9 B-BR6 48 40% DB
+ 5 mg/L FeSO.sub.4 18.8 77.3 B-BR8 48 40% DB + 5 mg/L FeSO.sub.4
19.2 81.9 B- 48 P2 + 40% DB 16.8 66.2 BR18 B- 48 P2 + 60 g/L YE
37.1 NF BR20 B-BR2 66 6 g/L YE + 5 mg/L FeSO.sub.4 9.5 31.5 B-BR4
66 6 g/L YE + 5 mg/L FeSO.sub.4 15.2 30.1 B-BR6 66 40% DB + 5 mg/L
FeSO.sub.4 27.4 53.6 B-BR8 66 40% DB + 5 mg/L FeSO.sub.4 25.2 61 B-
66 P2 + 40% DB 28.7 43.9 BR18 B- 66 P2 + 60 g/L YE 41.3 NF BR20
B-BR2 72 6 g/L YE + 5 mg/L FeSO.sub.4 9.5 29 B-BR4 72 6 g/L YE + 5
mg/L FeSO.sub.4 17.8 27.8 B-BR6 72 40% DB + 5 mg/L FeSO.sub.4 27.6
47.8 B-BR8 72 40% DB + 5 mg/L FeSO.sub.4 26.7 52.4 B- 72 P2 + 40%
DB 30.6 36.5 BR18 B- 72 P2 + 60 g/L YE 36.2 NF BR20 B-BR2 137 6 g/L
YE + 5 mg/L FeSO.sub.4 9.8 19.4 B-BR4 137 6 g/L YE + 5 mg/L
FeSO.sub.4 20.6 16.6 B-BR6 137 40% DB + 5 mg/L FeSO.sub.4 41.9 24.1
B-BR8 137 40% DB + 5 mg/L FeSO.sub.4 42.6 16.6 B- 137 P2 + 40% DB
40.2 4.3 BR18 B- 137 P2 + 60 g/L YE 36.3 NF BR20 NF: not found,
below detection limit YE: yeast extract DB: distillate bottom P2:
modified P2 media
Isolation of Butyrate Using an Acidic Resin
[0184] Amberlite.TM. IRA 400 resin (500 g) was washed with water
(2.times.500 mL) in a 5 L round bottom flask. Excess water was
removed carefully with a pipette before adding a fermentation broth
to the wet resin. Fermentation broth (2 L) containing 44.7 g/L
butyric acid was added and the resulting mixture was stirred using
a magnetic stirrer for 1.5 h. A small analytical sample was removed
and was found to contain 32.5 g/L butyric acid (27% loss) by GC
head space analysis. This indicated that 24.5 g of butyric acid was
adsorbed onto the resin.
[0185] The supernatant solution was poured off and the wet resin
was loaded onto a glass column with a wire sieve at the bottom to
prevent clogging. Fermentation broth was rinsed off the resin with
a flow of water (2 L) until the eluent was clear. The resin was
then transferred to a 2 L round bottom flask containing a magnetic
stirring bar and then treated with 100 mL of 1 N HCl followed by 8
mL of 6 N HCl. The resulting mixture was stirred for 5 minutes and
the pH was found to be 2.5, which was then subjected to
distillation. A total of five bulb to bulb distillations gave
150-250 mL fractions. In between distillations more water and 1 N
HCl was added to the resin. Fractions were made basic with 20%
aqueous NaOH and concentrated by rotary evaporation. Drying in
vacuo at 120.degree. C. overnight gave 16.23 g as a combined crude
solid or 14.13 g of sodium butyrate in the sample. This amounts to
a 57.7% recovery for the five distillations. Additional
distillations would lead to a higher recovery.
Isolation of Butyrate Using a Basic Resin
[0186] To 400 mL of butyric acid fermentation broth (44.58 g/L) in
a 1 L round bottom flask 100 mL of Amberlite.TM. IRN 150 (basic
component) wet resin was added. The resulting mixture was stirred
at room temperature for 2 hours and then allowed to stand for 10
minutes. A small analytical sample (1/2 mL) was removed and placed
in a vial. This was found to have 24.29 g/L butyric acid (54.49%
reduction) by GC head space analysis. This indicated that 9.72 g
was adsorbed onto the resin.
[0187] The supernatant solution was poured off and the remaining
broth was removed with a 50 mL pipette. The resin was rinsed with
water (8.times.25 mL) and then treated with a 10% solution of
H.sub.2SO.sub.4 in EtOH (50 mL). The resulting mixture was stirred
at room temperature for 5 minutes and then the ethanolic solution
was removed by pipette. The resin was then rinsed with EtOH
(10.times.25 mL), followed by water (10.times.25 mL). The EtOH
rinse solutions were combined and basified with 20% NaOH (pH 11)
and then concentrated by rotary evaporation. The water rinse
solutions were treated similarly and both solids were dried further
in vacuo at 120.degree. C. to give 6.74 g (72.57% sodium butyrate
by LC analysis) from ethanol and 1.90 g (80.44% sodium butyrate by
LC analysis) from water. The total recovery from the resin was
66.1%.
Conversion of Butyrate to Ethyl Butyrate
[0188] A crude mixture of solids containing a total of 8.9 g of
sodium butyrate was treated with 50 mL of ethanol in a 250 mL round
bottom flask and the resulting mixture was cooled in a water bath
and slowly treated with concentrated sulfuric acid (16 g) while
stiffing with a magnetic stirring bar. The round bottom flask was
fitted with a reflux condenser and the reaction mixture was boiled
for 4 hours under N.sub.2. After cooling to room temperature the
reaction mixture was poured into a separatory funnel containing a
150 mL aqueous solution of Na.sub.2HPO.sub.4 (40 g). The final pH
of the solution after mixing was 7. The top layer was separated out
and filtered through glass wool to remove sludge giving 4.5 mL of
ethyl butyrate. This sample was combined with other similar samples
to give about 29 g of a crude liquid that was distilled to give
23.6 g (88% purity by LC analysis) ethyl butyrate. The impurities
were mostly ethanol (9.2%) and ethyl acetate (2%).
Hydrogenolysis of Ethyl Butyrate
[0189] Ethyl butyrate (20.8 g, 0.176 mol) in 225 mL of dry ethanol
was added to 0.5% Re on alumina (8.1 g, reduced) in a 1 L stainless
steel autoclave. After purging with N.sub.2 and evacuating, the
resulting mixture was filled with 116 psi H.sub.2 and then stirred
at 600 rpm and heated at 270.degree. C. for a total of 25.5 h over
a 4 day period. The autoclave was depressurized to room temperature
each morning and then more H.sub.2 was added (108-112 psi).
Pressures ranging from 1400-1500 psi were used for the
hydrogenation. Gas chromatography head space analysis indicated a
greater than 65% molar conversion of ethyl butyrate with a greater
than 90% selectivity to n-butanol.
Biomass Produced L-Lactic Acid and Xylose Stream with Lactobacillus
rhamnosus
[0190] Saccharified biomass made utilizing similar steps as
described above was used as the sugar source to produce an L-lactic
acid/xylose stream.
[0191] The glucose to L-Lactic acid fermenting organism
Lactobacillus rhamnosus NRRL B-445 was grown in 25 mL of MRS medium
(BD Diagnostic Systems No.: 288130) from 250 uL freezer stocks. The
culture was incubated overnight in a shaker incubator at 37.degree.
C. and 150-200 rpm.
[0192] Fermentation to produce the lactic acid was conducted in a
bioreactor equipped with stirring paddle, heating mantel, stirring
impellors, pH monitoring probes and temperature monitoring
thermocouples.
[0193] The production medium for an experiment used 11 L of
saccharified biomass, 22 g of yeast extract, 1.6 mL of antifoam
AFE-0010. The media was heated to 70.degree. C. for 1 hour and then
cooled to 37.degree. C. The pH of the media was raised to 6.5 using
12.5N NaOH solution. The media was then inoculated with 1% (110 mL)
of the Lactobacillus rhamnosus. Fermentation was allowed to proceed
at 37.degree. C. while the solution was stirred at 200 rpm and the
pH maintained above 6.5. Glucose was completely consumed by 48
hours. The product is L-lactic acid as the sodium salt. The xylose
is essentially unconverted during the biomass conversion.
Biomass Produced D-Lactic Acid and Xylose Stream with Lactobacillus
coryniformis
[0194] Saccharified biomass made utilizing similar steps as
described above was used as the sugar source to produce an L-lactic
acid xylose stream.
[0195] The glucose to D-Lactic acid fermenting organism
Lactobacillus coryniformis subspecies torquens B-4390 was grown in
25 mL of MRS medium (BD Diagnostic Systems No.: 288130) from 250
.mu.L freezer stocks. The culture was incubated overnight at
37.degree. C. without agitation.
[0196] The production medium for an experiment used 644 mL of
saccharified biomass, 5 g/L of tryptone, and 100 .mu.L of antifoam
ME-0010. The media was heated to 70.degree. C. for 1 hour and then
cooled to 37.degree. C. The pH was raised to 6.5 using 12.5N NaOH
solution and maintained thereafter using the same base solution.
The media was inoculated with 1% of the B-4390 and the fermentation
wall allowed to proceed at 37.degree. C. while the media was
stirred at 200 rpm and the pH maintained at about 6.5. Glucose
consumption was complete in 144 hours. The product is D-lactic acid
as the sodium salt. The xylose is essentially unconverted during
the biomass conversion.
Processing of Sodium Lactate Solution
[0197] Both the D-lactic acid and L-lactic acid derived sodium
lactate were decolorized as described here. Fermentations were run
repeatedly to provide larger quantities of material and facilitate
the decolorization.
[0198] Thirty liters of fermentation medium containing sodium
lactate prepared by fermentation as described above were
centrifuged at 4200 rpm for 60 minutes. The supernatant was
filtered through a 0.22 micron cartridge filter producing 26.5 L of
filtrate. Nineteen liters of the filtrate were percolated through a
column containing 2.7 L of a highly porous styrenic polymeric bead
type resin, Mitsubishi Diaion SP-700, at a flow rate of 1.5 BV/h.
The first 1.5 L of eluate are discarded and the rest of the medium
and an additional 1.5 L of water are eluted and pooled. The
remaining portion of the medium was decolorized in a similar manner
resulting in 7.5 L of pale colored solution. The two batches of
decolorized material were pooled and stored in the cold if not used
immediately.
Desalination Electro Dialysis of Decolorized Lactate Solution
[0199] The decolorized medium prepared as described above was
subjected to electro dialysis using a desalination membrane.
[0200] The a reservoir of the Electrodialysis apparatus was charged
with the decolorized sodium lactate medium and the Concentrate
reservoir of the apparatus was charged with 4 L of deionized water.
Electrodialysis was continued for 5 hours using a voltage of 40 V
and a maximum current of 5 A.
[0201] This procedure produced a concentrated lactate stream with a
typical concentration of around 66 g/L (starting at 38 g/L) and a
concentrated xylose stream with a typical conductivity of 5
.mu.S/cm (starting 34 .mu.S/cm).
Bipolar Electrodialysis
[0202] The liquid in the stream in sodium lactate produced as
described above can be subjected to a second electro dialysis using
a bipolar membrane to produce a lactic acid solution and a sodium
hydroxide solution. The procedure that can be followed is described
here.
[0203] Sodium lactate (1.6 L) solution prepared by desalination
electrodialysis is added to the Diluate reservoir. Deionized water
(1 L) is added to each reservoir for the lactic acid and sodium
hydroxide streams. The electrodialysis is carried out using a
4-chamber electro dialysis cell fitted with a bipolar membrane
stack. The voltage is set to 23 V and the maximum current is set to
6.7 A. The dialysis can be carried out for 5 hours or until the
conductivity of the dilute stream is <5% of its starting
value.
[0204] This procedure produced a concentrated lactate stream with a
typical concentration of around 66 g/L (starting at 38 g/L) and a
xylose stream with a typical conductivity of 5 .mu.S/cm (starting
34 .mu.S/cm) and concentration of 30 g/L. The lactate stream is
typically 96% lactic acid to 4% xylose after the bipolar membrane
dialysis. The xylose stream is typically 93% xylose to 7% lactic
acid after the bipolar membrane dialysis.
[0205] Notwithstanding that the numerical ranges and parameters
setting forth the broad scope of the invention are approximations,
the numerical values set forth in the specific examples are
reported as precisely as possible. Any numerical value, however,
inherently contains error necessarily resulting from the standard
deviation found in its underlying respective testing measurements.
Furthermore, when numerical ranges are set forth herein, these
ranges are inclusive of the recited range end points (i.e., end
points may be used). When percentages by weight are used herein,
the numerical values reported are relative to the total weight.
[0206] Also, it should be understood that any numerical range
recited herein is intended to include all sub-ranges subsumed
therein. For example, a range of "1 to 10" is intended to include
all sub-ranges between (and including) the recited minimum value of
1 and the recited maximum value of 10, that is, having a minimum
value equal to or greater than 1 and a maximum value of equal to or
less than 10. The terms "one," "a," or "an" as used herein are
intended to include "at least one" or "one or more," unless
otherwise indicated.
[0207] Any patent, publication, or other disclosure material, in
whole or in part, that is said to be incorporated by reference
herein is incorporated herein only to the extent that the
incorporated material does not conflict with existing definitions,
statements, or other disclosure material set forth in this
disclosure. As such, and to the extent necessary, the disclosure as
explicitly set forth herein supersedes any conflicting material
incorporated herein by reference. Any material, or portion thereof,
that is said to be incorporated by reference herein, but which
conflicts with existing definitions, statements, or other
disclosure material set forth herein will only be incorporated to
the extent that no conflict arises between that incorporated
material and the existing disclosure material.
[0208] While this invention has been particularly shown and
described with references to preferred embodiments thereof, it will
be understood by those skilled in the art that various changes in
form and details may be made therein without departing from the
scope of the invention encompassed by the appended claims.
* * * * *