U.S. patent application number 14/299000 was filed with the patent office on 2014-09-25 for filtration.
The applicant listed for this patent is Xyleco, Inc.. Invention is credited to John M. CAHILL, Randy LAVIGNE, Thomas Craig MASTERMAN, Marshall MEDOFF, Solomon I. RODITI.
Application Number | 20140287469 14/299000 |
Document ID | / |
Family ID | 51491991 |
Filed Date | 2014-09-25 |
United States Patent
Application |
20140287469 |
Kind Code |
A1 |
MEDOFF; Marshall ; et
al. |
September 25, 2014 |
FILTRATION
Abstract
Biomass feedstocks (e.g., plant biomass, animal biomass, and
municipal waste biomass) are processed to produce useful products,
such as fuels. For example, systems are described that can be
useful for separating solids from liquids of saccharified biomass
material slurries.
Inventors: |
MEDOFF; Marshall;
(Brookline, MA) ; MASTERMAN; Thomas Craig;
(Rockport, MA) ; RODITI; Solomon I.; (Framingham,
MA) ; CAHILL; John M.; (Burlington, MA) ;
LAVIGNE; Randy; (Seabrook, NH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Xyleco, Inc. |
Woburn |
MA |
US |
|
|
Family ID: |
51491991 |
Appl. No.: |
14/299000 |
Filed: |
June 9, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
PCT/US14/21584 |
Mar 7, 2014 |
|
|
|
14299000 |
|
|
|
|
61774684 |
Mar 8, 2013 |
|
|
|
61774773 |
Mar 8, 2013 |
|
|
|
61774731 |
Mar 8, 2013 |
|
|
|
61774735 |
Mar 8, 2013 |
|
|
|
61774740 |
Mar 8, 2013 |
|
|
|
61774744 |
Mar 8, 2013 |
|
|
|
61774746 |
Mar 8, 2013 |
|
|
|
61774750 |
Mar 8, 2013 |
|
|
|
61774752 |
Mar 8, 2013 |
|
|
|
61774754 |
Mar 8, 2013 |
|
|
|
61774775 |
Mar 8, 2013 |
|
|
|
61774780 |
Mar 8, 2013 |
|
|
|
61774761 |
Mar 8, 2013 |
|
|
|
61774723 |
Mar 8, 2013 |
|
|
|
61793336 |
Mar 15, 2013 |
|
|
|
Current U.S.
Class: |
435/99 |
Current CPC
Class: |
B01D 15/02 20130101;
C13K 1/02 20130101; H01J 2237/31 20130101; C10L 2200/0476 20130101;
C10L 2290/36 20130101; H01J 2237/3165 20130101; B01D 61/445
20130101; B01J 2219/0886 20130101; B65G 53/04 20130101; C10G 1/00
20130101; C12M 47/00 20130101; H01J 37/317 20130101; Y02E 50/30
20130101; C12P 7/04 20130101; Y02E 60/16 20130101; B01J 19/085
20130101; B65G 53/40 20130101; C07C 29/149 20130101; C10L 9/08
20130101; C10L 2200/0469 20130101; C13K 13/002 20130101; E04B
2001/925 20130101; C10L 1/026 20130101; C12P 7/52 20130101; C12M
47/10 20130101; C12P 19/14 20130101; Y02P 20/133 20151101; C10L
1/023 20130101; C12P 2201/00 20130101; D21C 9/007 20130101; G21F
7/00 20130101; Y02E 50/10 20130101; C12P 7/10 20130101; B01J
2219/0879 20130101; C12P 7/06 20130101; B01J 2219/0869 20130101;
Y02W 10/33 20150501; B65G 27/00 20130101; B01D 61/44 20130101; G21K
5/10 20130101; E04B 1/92 20130101; Y02W 10/37 20150501; H01J
2237/202 20130101; C12P 7/56 20130101; C12P 2203/00 20130101; C12P
19/02 20130101; Y02W 10/40 20150501; B01D 53/32 20130101; C07C
31/12 20130101; C07C 29/149 20130101; C07C 31/12 20130101 |
Class at
Publication: |
435/99 |
International
Class: |
C12P 19/02 20060101
C12P019/02 |
Claims
1. A method of separating solids from liquids of a slurry, the
method comprising: saccharifying a biomass and applying the
saccharified biomass to a surface of a filter device.
2. The method of claim 1, wherein the saccharified biomass
comprises sugars selected from the group consisting of glucose,
xylose and mixtures thereof.
3. The method of claim 1, wherein the saccharified biomass
comprises an aqueous solvent.
4. The method of claim 1, wherein the saccharified biomass includes
cells selected from the group consisting of yeast cells, bacterial
cells, fungal cells or mixtures thereof.
5. The method of claim 1, wherein the saccharified biomass includes
protein material.
6. The method of claim 5, wherein the protein material is
substantially denatured protein material.
7. The method of claim 5, wherein the protein material includes an
enzyme material.
8. The method of claim 1, wherein the saccharified biomass includes
a fermentation product.
9. The method of claim 1, wherein the saccharified biomass includes
an alcohol.
10. The method of claim 9, wherein the alcohol is ethanol or
butanol.
11. The method of claim 1, wherein the saccharified biomass is
substantially devoid of one or more soluble sugars from which the
biomass is composed.
12. The method of claim 11, wherein the saccharified biomass is
substantially devoid of glucose.
13. The method of claims 12, wherein the saccharide biomass is
substantially devoid of xylose.
14. The method of claim 1, wherein the biomass has been
saccharified using one or more saccharification agent.
15. The method of claim 14, wherein the saccharification agent is
selected from the group consisting of enzymes, acids, bases,
oxidants and mixtures thereof.
16. The method of claim 14, wherein the saccharification agent is a
cellulolytic enzyme.
17. The method of claim 1, wherein the biomass has been treated to
reduce its recalcitrance prior to saccharification.
18. The method of claim 17, wherein recalcitrance has been reduced
by the application of electron beam radiation to the biomass.
19. The method of claim 1, wherein the filter device comprises a
rotatable drum having a filter face through which liquid of the
saccharified material can pass, while retaining solids of the
saccharified material thereon.
20. The methods of claim 1, further comprising utilizing a
vibratory screener to remove solids from the saccharified biomass
prior to and/or after applying the saccharified biomass to the
outer portion of the filter device.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of PCT/US 14/21584 filed
on Mar. 7, 2014, which claimed priority to the following
provisional applications: U.S. Ser. No. 61/774,684, filed Mar. 8,
2013; U.S. Ser. No. 61/774,773, filed Mar. 8, 2013; U.S. Ser. No.
61/774,731, filed Mar. 8, 2013; U.S. Ser. No. 61/774,735, filed
Mar. 8, 2013; U.S. Ser. No. 61/774,740, filed Mar. 8, 2013; U.S.
Ser. No. 61/774,744, filed Mar. 8, 2013; U.S. Ser. No. 61/774,746,
filed Mar. 8, 2013; U.S. Ser. No. 61/774,750, filed Mar. 8, 2013;
U.S. Ser. No. 61/774,752, filed Mar. 8, 2013; U.S. Ser. No.
61/774,754, filed Mar. 8, 2013; U.S. Ser. No. 61/774,775, filed
Mar. 8, 2013; U.S. Ser. No. 61/774,780, filed Mar. 8, 2013; U.S.
Ser. No. 61/774,761, filed Mar. 8, 2013; U.S. Ser. No. 61/774,723,
filed Mar. 8, 2013; and U.S. Ser. No. 61/793,336, filed Mar. 15,
2013. The full disclosure of each of these applications is
incorporated by reference herein.
BACKGROUND
[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] In general, the filtering of materials, e.g., biomass
materials are disclosed herein. Processes are disclosed herein for
saccharifying or liquifying a biomass material, e.g., cellulosic,
lignocellulosic and/or starchy feedstocks, by converting biomass
material to low molecular weight sugars, e.g., saccharifying the
feedstock, e.g., using an enzyme, e.g., one or more cellulase
and/or amylase. The invention also relates to converting a
feedstock to a product, e.g., by bioprocessing, such as
fermentation or other processing, such as hydrogenation or
esterification. The processes include utilizing filtration to
remove solids before, during or after saccharification and/or
fermentation. The solids can then be, for example, used for energy
cogeneration, used as a fermentation additive (e.g., nutrient), or
used as another feed material.
[0005] Methods, such as the saccharification of biomass to produce
sugars, produce liquids that can be viscous due to various
oligomers and the high loading of solids. In order to further
process the materials, e.g., sugars or the solids in the slurries
themselves, it is often advantageous to separate the liquids from
the solids. Methods that involve dilution (e.g., with water) can be
utilized to aid in processing, but these methods can incur a
downstream cost associated with the removal of added diluents. Some
of the methods described herein allow for the filtration of these
highly loaded and viscous feed-streams without clogging and/or
without significant dilution.
[0006] Generally the invention features systems and methods for
separating solids from liquids of a slurry (e.g., containing solids
and dissolved solids suspended in a liquid) including applying a
saccharified biomass material slurry to a surface (e.g., to an
outer portion) of a filter device. Optionally, a vibratory screener
can be utilized to remove some of the solids prior to applying the
saccharified material to the surface (e.g., outer portion) of the
filter device. For example, the filter device can be a rotary drum
filter device (e.g., a rotary vacuum drum filter device).
Optionally the saccharified biomass material slurry comprises
saccharified sugars, such as sugars selected from the group
consisting of glucose, xylose and mixtures of these. For example,
the sugars can be dissolved in and/or suspended in a solvent, such
as water and/or a non-aqueous solvent. The saccharified material
can also include cells, such as cells selected from the group
consisting of yeast cells, bacterial cells, fungal cells and
mixture of these cells. Optionally the saccharified material can
include protein material, such as enzyme material, denatured
protein material, peptides, peptide residues, amino acids and/or
denatured enzyme material. The saccharified material can include an
acid (e.g., lactic acid, butyric acid and/or acetic acid) and/or an
alcohol (e.g., ethanol and/or butanol). The saccharified material
can include fermentation products. In some instances, the
saccharified material is devoid of one or more soluble sugars from
which the biomass is composed. For example, the saccharified
material can be devoid of, glucose and/or xylose, such where the
sugar has be removed by any means (e.g., selective fermentation of
one or more of the sugars, chemical separation and removal of one
or more of the sugars).
[0007] In some implementations, the biomass has been saccharified
using one or more saccharification agents. Optionally, the
saccharification agent is selected from the group consisting of
enzymes, acids, bases, oxidants and mixtures of these. Optionally,
the selected saccharification agents can be combined in any order
to saccharify the biomass, for example, the biomass can be treated
with an acid and then with an enzyme, or with an oxidant and then
with an enzyme. In some implementations, the saccharification agent
includes sulfuric acid and an enzyme. Optionally or additionally,
the saccharification agent is a cellulolytic enzyme.
[0008] In some implementations, the biomass has been treated to
reduce its recalcitrance prior to saccharification. For example,
the recalcitrance of the biomass can be reduced relative to biomass
(e.g., biomass feedstock) in its native state prior to
saccharification. In some instances, reducing the recalcitrance of
the feedstock includes treating the feedstock with a physical
treatment. The treatment can include, for example, irradiation
(e.g., electron beam radiation), sonication, pyrolysis, oxidation,
steam explosion, chemical treatment, mechanical treatment and
combinations of these treatments. The treatment can include the
application of any one or more of the treatments disclosed herein,
applied alone or in any desired combination, and applied once or
multiple times.
[0009] Optionally, the methods described herein utilize a filter
device e.g., a rotary drum filter device, that includes a rotatable
drum having a filter face through which liquid of the saccharified
material (e.g., liquids of the slurry) can pass, while retaining
solids of the saccharified material thereon. The filter face can
have a filter aid extending outwardly therefrom. Optionally the
filter aid covers substantially the entire filter face of the
rotatable drum. The filter aid can include, for example, a filter
aid selected from the group consisting of diatomaceous earth,
celite, silica, pumice, perlite, alumina, zeolites, sand,
cellulosic material, (e.g. SOLKA-FLOC.RTM., International Fiber
Corporation, North Tonawanda, N.Y.) lignocellulosic material, and
mixtures of these. Optionally, the filter aid extends from the
filter face a distance of from about 0.5 mm to about 250 mm, such
as between about 1 mm and about 100 mm or about 1 mm to about 50 mm
or between about 2 mm to about 25 mm. The rotatable drum includes
an inner portion wherein the inner portion is maintained at a lower
pressure than the filter face. For example, the pressure difference
between the inner portion and the filter face can be maintained
between about 20 and about 25 inches of Hg while separating solids
from liquids in the slurry (e.g., the saccharified biomass).
Optionally, the inner portion of the drum is in communication with
a vacuum pump and/or a vacuum source, e.g., for maintaining the
pressure as described above. Optionally, the filter face of the
filter device includes a filter cloth such as a woven cloth, e.g.,
having a weave selected from the group consisting of a twill weave,
a plain weave, a satin weave, a knot weave, a basket weave, an
oxford weave and combinations of these. Optionally, the filter
cloth has a porosity rating ranging from about 1 to 100
CFM/ft.sup.2 (e.g., about 1-3, about 1-10, about 10-30, about
15-20, about 30-50, about 30-40, about 50 to 70). Optionally, the
filter device includes a knife for continuously removing the solids
deposited on the drum face as the drum is rotated relative to the
knife. For example, the knife moves in a direction perpendicularly
towards the drum face at a rate adjusted to continuously removes an
interfacial region comprising the solids of the saccharified
material and the filter aid. The rate, for example, can be adjusted
to maintain a preset pressure difference between the inner and
outer portions of the drum. Filtering biomass materials that have
been processed, e.g., saccharified and/or fermented, can be
challenging and slow. The processed biomass includes particles of
various sizes and shapes (e.g., fibers, granular particles,
micro-particles, nano-particles, colloids and larger particles),
polymers (e.g., enzymes, proteins, polysaccharides, lignin), live
and/or dead cells (e.g., from yeast, bacteria or fungi used to
process the biomass), and small molecules (e.g., amino acids,
monomeric sugars, organic acids, alcohols). The biomass filtering
systems described herein generally resist clogging and allow for
clarification of even the thickest biomass slurries.
[0010] Implementations of the invention can optionally include one
or more of the following summarized features. In some
implementations, the selected features can be applied or utilized
in any order while in other implementations a specific selected
sequence is applied or utilized. Individual features can be applied
or utilized more than once in any sequence and even continuously.
In addition, an entire sequence, or a portion of a sequence, of
applied or utilized features can be applied or utilized once,
repeatedly or continuously in any order. In some optional
implementations, the features can be applied or utilized with
different, or where applicable the same, set or varied,
quantitative or qualitative parameters as determined by a person
skilled in the art. For example, parameters of the features such as
size, individual dimensions (e.g., length, width, height), location
of, degree (e.g., to what extent such as the degree of
recalcitrance), duration, frequency of use, density, concentration,
intensity and speed can be varied or set, where applicable as
determined by a person of skill in the art.
[0011] Features, for example, include: a method of separating
solids from liquids of a slurry; saccharifying a biomass and
applying the saccharified biomass to a surface of a filter device;
a method of separating solids from liquids of a slurry;
saccharifying a biomass and applying the saccharified biomass to an
outer portion of a filter device; utilizing a rotary drum filter
device; filtering a saccharified biomass comprising glucose;
filtering a saccharified biomass comprising xylose; filtering a
saccharified biomass comprising an aqueous solvent; filtering a
saccharified biomass comprising a non-aqueous solvent; filtering a
saccharified biomass that includes cells; filtering a saccharified
biomass that includes yeast cells; filtering a saccharified biomass
that includes bacterial cells; filtering a saccharified biomass
that includes fungal cells; filtering a saccharified biomass that
includes protein material; filtering a saccharified biomass that
includes substantially denatured protein material; filtering a
saccharified biomass that includes protein material; filtering a
saccharified biomass that includes enzyme material; filtering a
saccharified biomass that includes a fermentation product;
filtering a saccharified biomass that includes an alcohol;
filtering a saccharified biomass that includes ethanol; filtering a
saccharified biomass that includes butanol; filtering a
saccharified biomass that includes an organic acid; filtering a
saccharified biomass that includes butyric acid; filtering a
saccharified biomass that is substantially devoid of one or more
soluble sugars from which the biomass is composed; utilizing a
biomass composition that includes glucose and filtering the
saccharified biomass when it is substantially devoid of glucose;
utilizing a biomass composition that includes xylose and filtering
the saccharified biomass when it is substantially devoid of xylose;
utilizing a biomass that has been saccharified using one or more
saccharification agent; utilizing a biomass that has been
saccharified by a saccharification agent that includes enzymes;
utilizing a biomass has been saccharified by a saccharification
agent that includes acids; utilizing a biomass that has been
saccharified by a saccharification agent that includes bases;
utilizing a biomass that has been saccharified by a
saccharification agent that includes oxidants; utilizing a
saccharification agent that includes sulfuric acid; utilizing a
saccharification agent that includes a cellulolytic enzyme;
utilizing a biomass that has been treated to reduce its
recalcitrance prior to saccharification; reducing the recalcitrance
of a biomass by treating the biomass with electron beam irradiation
prior to saccharification; utilizing a filter device that comprises
a rotatable drum having a filter face through which liquid of a
saccharified material can pass, while retaining solids of the
saccharified material thereon; utilizing a filter device that
comprises a rotatable drum having a filter face and the filter face
has a filter aid extending outwardly therefrom; utilizing a filter
aid that covers substantially the entire filter face of a rotatable
drum filter device; utilizing a filter aid that includes
diatomaceous earth; utilizing celite on a filter face; utilizing
diatomaceous earth on a filter face; utilizing pumice on a filter
face; utilizing perlite on a filter face; utilizing alumina on a
filter face; utilizing zeolites on a filter face; utilizing sand on
a filter face; utilizing cellulosic material on a filter face;
utilizing lignocellulosic material on a filter face; a filter aid
that extends from a filter face a distance of from between about
0.5 mm to about 250 mm; a filter aid that extends from a filter
face a distance of from between about 1 mm and about 100 mm; a
filter aid that extends from a filter face a distance of from
between about 1 mm to about 50 mm; a filter aid that extends from
the filter face a distance of from between about 0.5 mm to about
250 mm; a filter aid that extends from the filter face a distance
of from between about 2 mm to about 25 mm; a filter device that
includes a rotatable drum with an inner portion and the inner
portion is maintained at a lower pressure than the filter face;
utilizing a filter device that includes a rotatable drum with an
inner portion and the pressure difference between the inner portion
and the filter face is maintained between about 20 and about 25
inches of Hg; utilizing a filter device that includes a rotatable
drum with an inner portion and the inner portion is in
communication with a vacuum pump; utilizing a filter device that
includes a rotatable drum with an inner portion and the inner
portion is in communication with a vacuum source; utilizing a
filter device that includes a filter cloth; utilizing a filter
device that includes a woven filter cloth; utilizing a filter
device that includes a twill weave woven filter cloth; utilizing a
filter device that includes a plain weave woven filter cloth;
utilizing a filter device that includes a satin weave woven filter
cloth; utilizing a filter device that includes a knot weave woven
filter cloth; utilizing a filter device that includes a basket
weave woven filter cloth; utilizing a filter device that includes
an oxford weave woven filter cloth; utilizing a filter device that
includes a filter cloth that has a porosity rating range from about
1 to 100 CFM/ft.sup.2; utilizing a filter device that includes a
filter cloth that has a porosity rating range from about 1 to 3
CFM/ft.sup.2; utilizing a filter device that includes a filter
cloth that has a porosity rating range from about 1 to 10
CFM/ft.sup.2; utilizing a filter device that includes a filter
cloth that has a porosity rating range from about 10 to 30
CFM/ft.sup.2; utilizing a filter device that includes a filter
cloth that has a porosity rating range from about 15 to 20
CFM/ft.sup.2; utilizing a filter device that includes a filter
cloth that has a porosity rating range from about 30 to 50
CFM/ft.sup.2; utilizing a filter device that includes a filter
cloth that has a porosity rating range from about 50 to 70
CFM/ft.sup.2; utilizing a filter device that comprises a rotatable
drum having a filter face and a knife for continuously removing the
solids deposited on the drum face as the drum is rotated relative
to the knife; utilizing a filter device that comprises a rotatable
drum having a filter face and a knife for continuously removing the
solids deposited on the drum face as the drum is rotated relative
to the knife and the knife moves in a direction perpendicularly
towards the drum face at a rate adjusted to continuously removes an
interfacial region comprising the solids of a saccharified material
and a filter aid; utilizing a vibratory screener to remove solids
from the saccharified biomass prior to and/or after applying the
saccharified biomass to the outer portion of the filter device.
[0012] All publications, patent applications, patents, and other
references mentioned herein or attached hereto are incorporated by
reference in their entirety for all that they contain.
DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a highly diagrammatic view of a rotary vacuum drum
filtration (RVDF) system.
[0014] FIG. 1A is an enlarged view of an area of the RVDF system of
FIG. 1, where solids are scraped from the drum.
[0015] FIG. 2 shows some filter cloths.
[0016] FIGS. 3A, 3B and 3C are flow diagrams illustrating examples
of processes for filtration and concentration.
[0017] FIG. 4A shows a perspective exploded view of Rotary Pressure
Filtration device. FIGS. 4B, 4C, 4D and 4E show side diagrammatic
views illustrating the method of processing materials utilizing the
filtration device.
[0018] FIG. 5A shows a side diagrammatic view of Belt filter. FIGS.
5B, 5C, 5D and 5E show detail views of various zones of the
filtration device.
DETAILED DESCRIPTION
[0019] Using the methods described herein, biomass (e.g., plant
biomass, animal biomass, paper, and municipal waste biomass) can be
processed 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.
[0020] Many of the methods disclosed herein involve
saccharification of biomass to produce sugars, and in some cases
fermentation (or other bioprocessing or chemical transformations)
of the resulting sugars to form other products and/or
intermediates. After saccharification and/or fermentation (or other
processing), it is often desirable to remove solids by a filtration
process and in some cases to concentrate the liquid filtrate. The
present disclosure pertains to techniques for accomplishing this
filtration generally without clogging even with a thick (or highly
loaded slurries).
[0021] FIG. 1 shows an example of a rotary vacuum drum filtration
(RVDF) system 10. RVDF system 10 includes a drum 12, the lower
portion of which is positioned in a tank 13. The interior of the
drum is placed under vacuum, e.g., by communication with vacuum
pump 34. A moisture trap or water air separator 32 may be provided
to reduce moisture drawn into the vacuum pump. In some
implementations, the drum includes channels that extend from the
surface of the drum to a central hollow axis (not shown), and the
outer surface of the drum is covered by a filter cloth (also not
shown). The filter cloth, when the drum is in use, forms the outer
surface of drum 12. Some details of the filter cloth will be
discussed below, referring to FIG. 2, after some more details of
FIG. 1 are discussed.
[0022] Due to the porosity of the filter cloth and the underlying
channels in the surface of the drum, the vacuum drawn on the
interior of the drum is applied to a material on the surface of the
filter cloth. Tank 13 has an inlet 14 through which filter aid,
slurry or saccharified material can be fed. In some embodiments
there can be separate inlets for the filter aid and saccharified
material. The filter aid slurry or saccharified material can be fed
from a slurry container and saccharified material container (not
shown). The containers can be, for example, a drum, a tank, a
fermenter, or a saccharifier e.g., that is 100-150,000 gal in
volume, such as 10,000-75,000 gal (described below). The container
for the filter aid can include an agitator, such as a mixer
equipped with a mixing propeller to aid in suspending the filter
aid in the liquid phase (water). The container for the saccharified
material and tank 13 can also include an agitator. Tank 13 is fed
by a pump (e.g., positive displacement pump) or by gravity. The
tank also includes an overflow outlet 16 through which material can
exit the tank in case of overfilling.
[0023] When in use for filtering biomass material, such as a
saccharified material, the drum is preferably initially coated with
a layer 17 of filter aid. The drum is coated by adding the filter
aid slurry to tank 13 and rotating drum 12 at a constant rate
through the slurry while placing the interior of the drum under
vacuum, for example 10-15 inches Hg. Water is drawn through the
filter cloth and the filter aid is deposited as a uniform layer on
this cloth. The thickness of the layer of filter aid can be varied
and optimized for the process of interest (e.g., depending on the
concentration and composition of the saccharified material to be
processed). For example a layer 17 of filter aid slurry having a
thickness between about 0.1 and 30 inches can be used (e.g., 0.5
and 20 inches, 1 and 20 inches, 5 and 20 inches, 0.5 and 10, 0.5 to
5, 1 to 5, or 1 to 3 inches).
[0024] The filter aid increases the surface area of the drum
presented to the material to be filtered and improves the filtering
ability and capacity of the RVDF, generally allowing more material
and/or smaller particles to be filtered. Filter aids can include
diatomaceous earth, such as celite, a glass, such as a silica
glass, such as volcanic amorphous glass, such as perlite, a
cellulosic or lignocellulosic material, silica, alumina, zeolite,
sand or mixtures of any of these filter aids.
[0025] Once the drum has been coated with filter aid, saccharified
material 15 is added to tank 13. This can be done by first
exchanging the filter aid with water and then adding the
saccharified material, or by simply adding the saccharified
material and inter-mixing it with the filter aid slurry which is
slowly diluted and replaced as the liquids are drawn through the
drum filter. Alternatively, filter aid can be continuously added
and the filter aid kept at a low concentration in the saccharified
material, which can increase the efficiency of the filtration but
which also tends to increase the cost of filtration.
[0026] The vacuum drawn is typically increased when filtering
saccharified material, for example to between 20 and 30 inches of
Hg (e.g., between about 20 and 25 inches or between about 25 and 30
inches). It is preferable not to allow the surface of the drum with
the filter aid and saccharified material to completely dry out,
since this can lead to channel formation through the filter aid
which may reduce filter efficiency. During use for filtering the
saccharified material, the drum 12 is continuously rotated in the
direction of arrow A, picking up a layer 18 of the saccharified
material from the tank 13. Optionally, the filter drum is passed
beneath one or more shower heads or bars 20, which spray a wash
liquid (e.g., water) 22 onto the layer 18. The wash liquid aids in
extracting out soluble material from the solids.
[0027] The vacuum generated by vacuum pump 34 draws liquid out of
the layer and into the inside of the drum 12 through the pores of
the filter cloth. A filtrate receiver 30 is connected by a tube to
a seal tank 26, which receives the filtrates (wash water and liquid
and dilute solids from the saccharified material). A filtrate pump
31 is engaged to move the filtrates from the system to a collection
tank or other receiving area (not shown). In an alternate
embodiment, the filtrate receiver is directly connected to pump 31
and the seal tank 26 is not used.
[0028] Vacuum pump 34 can be replaced by alternative vacuum
sources. For example, an injector (e.g., steam injector,
educator-jet pump) can be used.
[0029] Between layers 17 and 18 there is an interfacial region 40,
as shown in FIG. 1A. The interfacial region includes both
saccharified material and filter aid. The interfacial region can
include a concentration gradient of material, for example,
perpendicular towards the drum surface, transitioning from
substantially saccharified material solids to filter aid. Knife 28
removes a layer of solid from the surface of the drum, and in ideal
operation, removes the saccharified material and the interfacial
region. If the interfacial region is not removed, this interfacial
region grows and can impede the flow of fluids through the filter
drum. This impediment can cause foaming due to a pressure drop on
the inside of the drum, or even complete blockage of the
filtration. Thus, if the interfacial region and filter aid layer is
not removed, the amount of material that can be filtered is reduced
and filter aid material is wasted.
[0030] The knife 28 is slowly moved towards the drum at a rate to
continuously remove the saccharified material and the interfacial
region. The rate of movement of the knife can be adjusted manually
or can be adjusted automatically, and may be based on, for example,
the vacuum measured in the interior of the drum, or an optical
detector directed at layers 17, 18 and/or 40. For example, if
vacuum measurement is used to control the rate of knife movement,
an optimal vacuum of 20-25 inches Hg can be maintained by
increasing the knife speed if the vacuum rises above 25 inches Hg,
and reducing the knife speed if the vacuum drops to below 20 inches
of Hg. The solution of saccharified material that is filtered can
have between about 1 and 90 wt. % suspended solids (e.g., between
about 1 and 80 wt. %, between about 1 and 70 wt. %, between about 1
and 60 wt. %, between about 1 and 50 wt. %, between about 1 and 40
wt. %, between about 1 and 30 wt. %, between about 1 and 20 wt. %,
between about 5 and 80 wt. %, between about 5 and 60 wt. %, between
about 5 and 40 wt. %, between about 5 and 20 wt. %, between about
10 and 80 wt. %, between about 10 and 60 wt. %, between about 10
and 40 wt. %, between about 10 and 20 wt. %, between about 15 and
80 wt. %, between about 15 and 60 wt. %, between about 15 and 40
wt. %, between about 15 and 20 wt. %, between about 20 and 80 wt.
%, between about 20 and 60 wt. %, between about 20 and 40 wt. %,
between about 5 and 20 wt. %, between about 30 and 80 wt. %,
between about 30 and 60 wt. %, between about 30 and 40 wt. %,
between about 40 and 80 wt. %, between about 40 and 60 wt. %).
[0031] As the layer 18 travels as indicated by arrow A, it becomes
drier and drier due to the vacuum drawing liquid out of the layer
and into the drum. By the time it reaches knife 28 it is relatively
dry, e.g., having a moisture content of less than about 50% (less
than 40%, less than 35%, less than 30%, less than 25% or even less
than 20%), for example between 20 and 50%, between 20 and 40%, or
between 30 and 50%.
[0032] The choice of the filter cloth depends on the application,
e.g., the degree of saccharification and initial particle size of
the biomass. The filter cloth is porous (e.g., permeable), to allow
fluid to be drawn from material on its surface to the interior of
the drum by the vacuum. For example, the filter cloth may be in the
form of a wire screen, mesh, woven cloth or the like, and may be
made of metal, synthetic fiber (e.g., polypropylene, polyester,
polyamide, poly vinyl alcohol), natural fiber (e.g., cotton) or
combinations of these and/or other materials. Cloths with porosity
rating ranges from about 1 to 100 CFM/ft.sup.2 can be utilized
(e.g., about 1-3, about 1-10, about 10-30, about 15-20, about 30 to
50, about 30-40, about 50 to 70). The porosity rating,
CFM/ft.sup.2, for the cloth is determined by flowing air through
the cloth and is the cubic feet per minute of air passing through
one square foot of the media at 0.5 inches (water column) loss. The
filter cloth can be woven, for example, with a twill weave, a plain
weave, a satin weave, a knot weave, a basket weave, oxford weave
and combinations of these. Different filament types can also be
utilized, for example, spun, multifilament, monofilament,
calendared multifilament, and combinations of these. FIG. 2 shows
some types of filter cloths that can be used on the drum 12. For
example 210 is a polyester plain weave filter cloth with a porosity
of 45 Lm.sup.-2 sec.sup.-1 (228.60 CFM/ft.sup.2), 220 is a
polyester twill weave with a porosity of 54 Lm.sup.-2 sec.sup.-1
(274.32 CFM/ft.sup.2), 230 is a polyester satin weave with a
porosity of 22 Lm.sup.-2 sec.sup.-1 (111.76 CFM/ft.sup.2) and 240
is a polyester with a porosity of 22 Lm.sup.-2 sec.sup.-1 (111.76
CFM/ft.sup.2).
[0033] Three examples of how filtration and concentration can be
used in a feedstock conversion process are shown in FIGS. 3A, 3B
and 3C. In all three examples,
RVDF is used to separate a distillate bottom into a solid portion
and a liquid portion. After removal of the solids from the
distillate bottom, the filtrate can be subjected to further
processing. Other examples are recognized as inventive that have
not shown in the figures. For example, processes where filtration
using a RVDF is applied before fermentation are optional
embodiments of the invention.
[0034] In the process shown in FIG. 3A, RVDF 340 is used to filter
the distillate bottom (e.g., a concentrated mixture) that is
obtained by saccharification 310, fermentation 320, and then
distillation 330.
[0035] In the process shown in FIG. 3B, RVDF 340 is used to filter
a mixture that is obtained by saccharification 310, pre-filtration
with a centrifuge 350, and then distillation 330. The centrifuge
can be, for example, a continuous scroll decanter centrifuge.
[0036] In the process shown in FIG. 3C, RVDF 340 is performed after
the sequence of; saccharification 310, pre-filtration with a
vibratory screening 360, and then distillation 330. The vibratory
screener can have, for example, a mesh of between about 10-200
(e.g., between about 20-100, between about 20 and 90, between about
20 and 80, between about 20 and 70, between about 20 and 60,
between about 20 and 50, between about 20 and 40, between about 20
and 30, between about 30 and 90, between about 30 and 80, between
about 30 and 70, between about 30 and 60, between about 30 and 50,
between about 30 and 40, between about 40 and 90, between about 40
and 80, between about 40 and 70, between about 40 and 60, between
about 40 and 50, between about 50 and 90, between about 50 and 80,
between about 50 and 70, between about 50 and 60, between about 60
and 90, between about 60 and 80, between about 60 and 70, between
about 70 and 80, between about 70 and 90, between about 80 and 90,
between about 50 and 150, between about 80-180, between about
50-110, between about 60-120, between about 40 and 110, between
about 150 and 200).
[0037] In some embodiments, prior to fermentation, it is preferable
to remove a portion of the solids, leaving a suspension with
between about 0 and 20 wt. % solids, (e.g., between about 1 and 10
wt. %, between about 5 and 10 wt. %).
[0038] It may also be preferable to denature any proteins that may
be present after the saccharification and/or fermentation. For
example the proteins may be denatured by raising or lowering the pH
and/or heating the solutions.
[0039] In each case, the solids recovered by RVDF can, for example,
be burned in a co-generation process to generate energy, used as a
media additive in the fermentation processes discussed herein,
and/or used as feed or other products.
[0040] In some implementations, centrifugation or other filtration
techniques may be used instead of or in addition to RVDF. For
example, lignin and other solids may be removed at any desired
stage of the process by centrifugation, e.g., using a continuous
scroll decanter centrifuge.
[0041] Some more details and reiterations of processes for treating
a feedstock that can be utilized, for example, with the embodiments
already discussed above, or in other embodiments, are described in
the following disclosures.
Systems for Treating a Feedstock
[0042] Filtering systems, methods and equipment (e.g., RVDF) can be
applied to materials that have been processed as described above
and also as described anywhere herein.
[0043] For example, processes for conversion of a feedstock to
sugars and other products, in which the methods discuss above may
be used, can include, for example, optionally physically
pre-treating the feedstock, e.g., to reduce its size, before and/or
after this treatment, optionally treating the feedstock to reduce
its recalcitrance (e.g., by irradiation), and saccharifying the
feedstock to form a sugar solution. Saccharification can be
performed by mixing a dispersion of the feedstock in a liquid
medium, e.g., water with an enzyme, as will be discussed in detail
below. During or after saccharification, the mixture (if
saccharification is to be partially or completely performed en
route) or solution can be transported, e.g., by pipeline, railcar,
truck or barge, to a manufacturing plant. After saccharification
the solution can be filtered, for example utilizing RVDF. At the
plant, the solution can be bioprocessed, e.g., fermented, to
produce a desired product or intermediate, which can then be
processed further, e.g., by distillation, RVDF. The individual
processing steps, materials used and examples of products and
intermediates that may be formed will be described in detail
below
Radiation Treatment
[0044] 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 280 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.
[0045] 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.
[0046] 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.
[0047] Gamma radiation has the advantage of a significant
penetration depth into a variety of material in the sample.
[0048] 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 10.sup.3, 10.sup.4, 10.sup.5, 10.sup.6, or even
greater than 10.sup.7 eV. In some embodiments, the electromagnetic
radiation has energy per photon of between 10.sup.4 and 10.sup.7,
e.g., between 10.sup.5 and 10.sup.6 eV. The electromagnetic
radiation can have a frequency of, e.g., greater than 10.sup.16 Hz,
greater than 10.sup.17 Hz, 10.sup.18, 10.sup.19, 10.sup.20, or even
greater than 10.sup.21 Hz. In some embodiments, the electromagnetic
radiation has a frequency of between 10.sup.18 and 10.sup.22 Hz,
e.g., between 10.sup.19 to 10.sup.21 Hz.
[0049] 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.
[0050] 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.
[0051] 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.
[0052] 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).
[0053] 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/cm.sup.3).
[0054] 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).
[0055] 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.
[0056] 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.
[0057] 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.degree. 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. %.
[0058] 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.
[0059] 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.
[0060] 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.
[0061] 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.
[0062] 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.
[0063] 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
[0064] 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=Eulers 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.
[0065] 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-Z" 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.
[0066] 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
[0067] 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.
[0068] 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.
[0069] 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.
[0070] 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.
[0071] Sources for ultraviolet radiation include deuterium or
cadmium lamps.
[0072] Sources for infrared radiation include sapphire, zinc, or
selenide window ceramic lamps.
[0073] Sources for microwaves include klystrons, Slevin type RF
sources, or atom beam sources that employ hydrogen, oxygen, or
nitrogen gases.
[0074] 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.
[0075] 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 lmillion, 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.
[0076] 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.
[0077] 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.
[0078] 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/cm.sup.3, 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.
[0079] Electron beam irradiation devices may be procured
commercially or built. For example, elements or components such
inductors, capacitors, casings, power sources, cables, wiring,
voltage control systems, current control elements, insulating
material, microcontrollers and cooling equipment can be purchased
and assembled into a device. Optionally, a commercial device can be
modified and/or adapted. For example, devices and components can be
purchased from any of the commercial sources described herein
including Ion Beam Applications (Louvain-la-Neuve, Belgium), Wasik
Associates Inc. (Dracut, Mass.), NHV Corporation (Japan), the Titan
Corporation (San Diego, Calif.), Vivirad High Voltage Corp
(Billerica, Mass.) and/or Budker Laboratories (Russia). Typical
electron energies can be 0.5 MeV, 1 MeV, 2 MeV, 4.5 MeV, 7.5 MeV,
or 10 MeV. Typical electron beam irradiation device power can be 1
kW, 5 kW, 10 kW, 20 kW, 50 kW, 60 kW, 70 kW, 80 kW, 90 kW, 100 kW,
125 kW, 150 kW, 175 kW, 200 kW, 250 kW, 300 kW, 350 kW, 400 kW, 450
kW, 500 kW, 600 kW, 700 kW, 800 kW, 900 kW or even 1000 kW.
Accelerators that can be used include NHV irradiators medium energy
series EPS-500 (e.g., 500 kV accelerator voltage and 65, 100 or 150
mA beam current), EPS-800 (e.g., 800 kV accelerator voltage and 65
or 100 mA beam current), or EPS-1000 (e.g., 1000 kV accelerator
voltage and 65 or 100 mA beam current). Also, accelerators from
NHV's high energy series can be used such as EPS-1500 (e.g., 1500
kV accelerator voltage and 65 mA beam current), EPS-2000 (e.g.,
2000 kV accelerator voltage and 50 mA beam current), EPS-3000
(e.g., 3000 kV accelerator voltage and 50 mA beam current) and
EPS-5000 (e.g., 5000 and 30 mA beam current).
[0080] 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.
[0081] 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
[0082] 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
Heating and Throughput During Radiation Treatment
[0083] 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.
[0084] 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, C.sub.p 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. At high temperatures, deviation from
the calculated temperatures is expected due to decomposition of the
biomass.
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
[0085] 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.).
[0086] 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/Dtime, 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.times.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
[0087] 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.
[0088] 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).
[0089] 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.
[0090] 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.
Beam Dumps
[0091] The embodiments disclosed herein can also include a beam
dump when utilizing a radiation treatment. A beam dump's purpose is
to safely absorb a beam of charged particles. Like a beam stop, a
beam dump can be used to block the beam of charged particles.
However, a beam dump is much more robust than a beam stop, and is
intended to block the full power of the electron beam for an
extended period of time. They are often used to block the beam as
the accelerator is powering up.
[0092] Beam dumps are also designed to accommodate the heat
generated by such beams, and are usually made from materials such
as copper, aluminum, carbon, beryllium, tungsten, or mercury. Beam
dumps can be cooled, for example, using a cooling fluid that can be
in thermal contact with the beam dump.
Biomass Materials
[0093] Lignocellulosic materials, such as can be used in the
methods and equipment described herein 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.
[0094] In some cases, the lignocellulosic material includes
corncobs. Ground or hammermilled 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.
[0095] 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.
[0096] 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.
[0097] 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.
[0098] Cellulosic materials can also include lignocellulosic
materials which have been partially or fully de-lignified.
[0099] 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, cassaya,
kudzu, ocra, 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.
[0100] Microbial materials that can be used as feedstock can
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 femptoplankton), 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.
[0101] 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.
[0102] Any of the methods described herein can be practiced with
mixtures of any biomass materials described herein.
Other Materials
[0103] Other materials (e.g., natural or synthetic materials), for
example polymers, can be treated and/or made utilizing the methods,
equipment and systems described hererin. For example polyethylene
(e.g., linear low density ethylene and high density polyethylene),
polystyrenes, sulfonated polystyenes, poly (vinyl chloride),
polyesters (e.g., nylons, DACRON.TM., KODEL.TM.), polyalkylene
esters, poly vinyl esters, polyamides (e.g., KEVLAR.TM.)
polyethylene terephthalate, cellulose acetate, acetal, poly
acrylonitrile, polycarbonates (e.g., LEXAN.TM.), acrylics [e.g.,
poly (methyl methacrylate), poly(methyl methacrylate),
polyacrylnitriles], Poly urethanes, polypropylene, poly butadiene,
polyisobutylene, polyacrylonitrile, polychloroprene (e.g.
neoprene), poly(cis-1,4-isoprene) [e.g., natural rubber],
poly(trans-1,4-isoprene) [e.g., gutta percha], phenol formaldehyde,
melamine formaldehyde, epoxides, polyesters, poly amines,
polycarboxylic acids, polylactic acids, polyvinyl alcohols,
polyanhydrides, poly fluoro carbons (e.g., TEFLON.TM.), silicons
(e.g., silicone rubber), polysilanes, poly ethers (e.g.,
polyethylene oxide, polypropylene oxide), waxes, oils and mixtures
of these. Also included are plastics, rubbers, elastomers, fibers,
waxes, gels, oils, adhesives, thermoplastics, thermosets,
biodegradabile polymers, resins made with these polymers, other
polymers, other materials and combinations thereof. The polymers
can be made by any useful method including cationic polymerization,
anionic polymerization, radical polymerization, methathesis
polymerization, ring opening polymerization, graft polymerization,
addition polymerization. In some cases the treatments disclosed
herein can be used, for example, for radically initiated graft
polymerization and cross linking. Composites of polymers, for
example with glass, metals, biomass (e.g., fibers, particles),
ceramics can also be treated and/or made.
[0104] Other materials that can be treated by using the methods,
systems and equipment disclosed herein are ceramic materials,
minerals, metals, inorganic compounds. For example, silicon and
germanium crystals, silicon nitrides, metal oxides, semiconductors,
insulators, cements and or conductors.
[0105] In addition, manufactured multipart or shaped materials
(e.g., molded, extruded, welded, riveted, layered or combined in
any way) can be treated, for example, cables, pipes, boards,
enclosures, integrated semiconductor chips, circuit boards, wires,
tires, windows, laminated materials, gears, belts, machines,
combinations of these. For example, treating a material by the
methods described herein can modify the surfaces, for example,
making them susceptible to further functionalization, combinations
(e.g., welding) and/or treatment can cross link the materials.
Biomass Material Preparation--Mechanical Treatments
[0106] 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. %).
[0107] 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 published
Jul. 5, 2011, the entire disclosure of which is hereby incorporated
by reference.
[0108] 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, such as a vibratory
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.
[0109] 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.
[0110] Optional pre-treatment processing can include heating the
material. For example a portion of a conveyor conveying the biomass
or other material can be sent through a heated zone. The heated
zone 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. 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.
[0111] Optionally, pre-treatment processing can include cooling the
material. Cooling material is described in U.S. Pat. No. 7,900,857
published Mar. 8, 2011, 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.
[0112] Another optional pre-treatment processing method can include
adding a material to the biomass or other feedstocks. 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 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.
[0113] Biomass can be delivered to conveyor (e.g., vibratory
conveyors that can be 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).
[0114] 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, 0.100+/-0.025 inches, 0.150+/-0.025 inches,
0.200+/-0.025 inches, 0.250+/-0.025 inches, 0.300+/-0.025 inches,
0.350+/-0.025 inches, 0.400+/-0.025 inches, 0.450+/-0.025 inches,
0.500+/-0.025 inches, 0.550+/-0.025 inches, 0.600+/-0.025 inches,
0.700+/-0.025 inches, 0.750+/-0.025 inches, 0.800+/-0.025 inches,
0.850+/-0.025 inches, 0.900+/-0.025 inches, 0.900+/-0.025
inches.
[0115] Generally, it is preferred to convey the material as quickly
as possible through the electron beam to maximize throughput. For
example the material can be conveyed at rates of at least 1 ft/min,
e.g., at least 2 ft/min, at least 3 ft/min, at least 4 ft/min, at
least 5 ft/min, at least 10 ft/min, at least 15 ft/min, 20, 25, 30,
35, 40, 45, 50 ft/min. The rate of conveying is related to the beam
current, for example, for a 1/4 inch thick biomass and 100 mA, the
conveyor can move at about 20 ft/min to provide a useful
irradiation dosage, at 50 mA the conveyor can move at about 10
ft/min to provide approximately the same irradiation dosage.
[0116] After the biomass material has been conveyed through the
radiation zone, optional post-treatment processing can be done. The
optional post-treatment processing can, for example, be a process
described with respect to the pre-irradiation processing. For
example, the biomass can be screened, heated, cooled, and/or
combined with additives. Uniquely to post-irradiation, quenching of
the radicals can occur, for example, quenching of radicals by the
addition of fluids or gases (e.g., oxygen, nitrous oxide, ammonia,
liquids), using pressure, heat, and/or the addition of radical
scavengers. For example, the biomass can be conveyed out of the
enclosed conveyor and exposed to a gas (e.g., oxygen) where it is
quenched, forming carboxylated groups. In one embodiment the
biomass is exposed during irradiation to the reactive gas or fluid.
Quenching of biomass that has been irradiated is described in U.S.
Pat. No. 8,083,906 published Dec. 27, 2011, the entire disclosure
of which is incorporate herein by reference.
[0117] If desired, one or more mechanical treatments can be used in
addition to irradiation to further reduce the recalcitrance of the
carbohydrate-containing material. These processes can be applied
before, during and or after irradiation.
[0118] 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.
[0119] 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.
[0120] 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.
[0121] 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 bun 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.
[0122] 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.
[0123] 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.
[0124] 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.
[0125] 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.
[0126] 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.
[0127] 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.
[0128] 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.
[0129] 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.
Sonication, Pyrolysis, Oxidation, Steam Explosion
[0130] 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.
Intermediates and Products
[0131] Using the processes described herein, the biomass material
can be converted to one or more products, such as energy, fuels,
foods and materials. For example, 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 can be produced. 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.
[0132] 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, 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,
methylmethacrylate, D-lactic acid, L-Lactic acid, pyruvic acid,
polylactic acid, citric acid, formic acid, acetic acid, propionic
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.
[0133] 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.
[0134] 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, by
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.
[0135] 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.
[0136] 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.
[0137] 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.
Lignin Derived Products
[0138] 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.
[0139] 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.
[0140] When used 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.
[0141] When used as an emulsifier, the lignin or lignosulfonates
can be used, e.g., in asphalt, pigments and dyes, pesticides and
wax emulsions.
[0142] When used 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.
[0143] For energy production lignin generally has a higher energy
content than holocellulose (cellulose and hemicellulose) since it
contains more carbon than homocellulose. 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.
Saccharification
[0144] As previously described, 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.
[0145] As previously disclosed, 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.
[0146] 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).
[0147] 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.
[0148] Therefore, the treated biomass materials can be
saccharified, by combining the material and a cellulase enzyme in a
fluid 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.
[0149] 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.
[0150] 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.
[0151] 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.
[0152] 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 weight. 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.
[0153] 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.
[0154] 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
[0155] 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).
[0156] 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
[0157] In the processes described herein, for example, after
saccharification, sugars (e.g., glucose and xylose) can be isolated
and/or purified. For example, sugars can be isolated and/or
purified by precipitation, crystallization, chromatography (e.g.,
simulated moving bed chromatography, high pressure chromatography),
electrodialysis, centrifugation, extraction, any other isolation
method known in the art, and combinations thereof.
Hydrogenation and Other Chemical Transformations
[0158] 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. Ser. No. 13/934,704 filed Jul. 3, 2013, the entire disclosure
of which is incorporated herein by reference in its entirety.
Fermentation
[0159] 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.
[0160] 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.
[0161] 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.
[0162] 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.
[0163] "Fermentation" includes the methods and products that are
disclosed in applications No. PCT/US2012/71093 published Jun. 27,
2013, PCT/US2012/71907 published Jun. 27, 2012, and
PCT/US2012/71083 published Jun. 27, 2012 the contents of which are
incorporated by reference herein in their entirety.
[0164] 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 U.S. 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
[0165] 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.
[0166] 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 Sacchromyces 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).
[0167] 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.
[0168] 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,
Anaerobiospirillium 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. utilis VKM Y-74, C. utilis 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.
[0169] Many such microbial strains are publicly available, either
commercially or through depositories such as the ATCC (American
Type Culture Collection, Manassas, Va., USA), the NRRL
(Agricultural Research Sevice Culture Collection, Peoria, Ill.,
USA), or the DSMZ (Deutsche Sammlung von Mikroorganismen and
Zellkulturen GmbH, Braunschweig, Germany), to name a few.
[0170] 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. (available from
Alltech, now Lalemand), GERT STRAND.RTM. (available from Gert
Strand AB, Sweden) and FERMOL.RTM. (available from DSM
Specialties).
Distillation
[0171] As previously described, 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
[0172] In other embodiments utilizing the methods and systems
described herein, hydrocarbon-containing materials, for example
mixed with biomass 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
[0173] Various conveying systems can be used to convey the biomass
material, for example, as discussed, 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. Vibratory conveyors are described in
PCT/US2013/64289 filed Oct. 10, 2013 the full disclosure of which
is incorporated by reference herein.
[0174] Vibratory conveyors are particularly useful for spreading
the material and producing a uniform layer on the conveyor trough
surface. For example the initial feedstock can form a pile of
material that can be at least four feet high (e.g., at least about
3 feet, at least about 2 feet, at least about 1 foot, at least
about 6 inches, at least about 5 inches, at least about, 4 inches,
at least about 3 inches, at least about 2 inches, at least about 1
inch, at least about 1/2 inch) and spans less than the width of the
conveyor (e.g., less than about 10%, less than about 20%, less than
about 30%, less than about 40%, less than about 50%, less than
about 60%, less than about 70%, less than about 80%, less than
about 90%, less than about 95%, less than about 99%). The vibratory
conveyor can spread the material to span the entire width of the
conveyor trough and have a uniform thickness, preferably as
discussed above. In some cases, an additional spreading method can
be useful. For example, a spreader such as a broadcast spreader, a
drop spreader (e.g., a CHRISTY SPREADER.TM.) or combinations
thereof can be used to drop (e.g., place, pour, spill and/or
sprinkle) the feedstock over a wide area. Optionally, the spreader
can deliver the biomass as a wide shower or curtain onto the
vibratory conveyor. Additionally, a second conveyor, upstream from
the first conveyor (e.g., the first conveyor is used in the
irradiation of the feedstock), can drop biomass onto the first
conveyor, where the second conveyor can have a width transverse to
the direction of conveying smaller than the first conveyor. In
particular, when the second conveyor is a vibratory conveyor, the
feedstock is spread by the action of the second and first conveyor.
In some optional embodiments, the second conveyor ends in a bias
cross cut discharge (e.g., a bias cut with a ratio of 4:1) so that
the material can be dropped as a wide curtain (e.g., wider than the
width of the second conveyor) onto the first conveyor. The initial
drop area of the biomass by the spreader (e.g., broadcast spreader,
drop spreader, conveyor, or cross cut vibratory conveyor) can span
the entire width of the first vibratory conveyor, or it can span
part of this width. Once dropped onto the conveyor, the material is
spread even more uniformly by the vibrations of the conveyor so
that, preferably, the entire width of the conveyor is covered with
a uniform layer of biomass. In some embodiments combinations of
spreaders can be used. Some methods of spreading a feed stock are
described in U.S. Pat. No. 7,153,533, filed Jul. 23, 2002 and
published Dec. 26, 2006, the entire disclosure of which is
incorporated herein by reference.
[0175] Generally, it is preferred to convey the material as quickly
as possible through an electron beam to maximize throughput. For
example, the material can be conveyed at rates of at least 1
ft/min, e.g., at least 2 ft/min, at least 3 ft/min, at least 4
ft/min, at least 5 ft/min, at least 10 ft/min, at least 15 ft/min,
at least 20 ft/min, at least 25 ft/min, at least 30 ft/min, at
least 40 ft/min, at least 50 ft/min, at least 60 ft/min, at least
70 ft/min, at least 80 ft/min, at least 90 ft/min. The rate of
conveying is related to the beam current and targeted irradiation
dose, for example, for a 1/4 inch thick biomass spread over a 5.5
foot wide conveyor and 100 mA, the conveyor can move at about 20
ft/min to provide a useful irradiation dosage (e.g. about 10 Mrad
for a single pass), at 50 mA the conveyor can move at about 10
ft/min to provide approximately the same irradiation dosage.
[0176] The rate at which material can be conveyed depends on the
shape and mass of the material being conveyed, and the desired
treatment. Flowing materials e.g., particulate materials, are
particularly amenable to conveying with vibratory conveyors.
Conveying speeds can, for example be, at least 100 lb/hr (e.g., at
least 500 lb/hr, at least 1000 lb/hr, at least 2000 lb/hr, at least
3000 lb/hr, at least 4000 lb/hr, at least 5000 lb/hr, at least
10,000 lb/hr, at least 15, 000 lb/hr, or even at least 25,000
lb/hr). Some typical conveying speeds can be between about 1000 and
10,000 lb/hr, (e.g., between about 1000 lb/hr and 8000 lb/hr,
between about 2000 and 7000 lb/hr, between about 2000 and 6000
lb/hr, between about 2000 and 5000 lb/hr, between about 2000 and
4500 lb/hr, between about 1500 and 5000 lb/hr, between about 3000
and 7000 lb/hr, between about 3000 and 6000 lb/hr, between about
4000 and 6000 lb/hr and between about 4000 and 5000 lb/hr). Typical
conveying speeds depend on the density of the material. For
example, for a biomass with a density of about 35 lb/ft.sup.3, and
a conveying speed of about 5000 lb/hr, the material is conveyed at
a rate of about 143 ft.sup.3/hr, if the material is 1/4'' thick and
is in a trough 5.5 ft wide, the material is conveyed at a rate of
about 1250 ft/hr (about 21 ft/min). Rates of conveying the material
can therefore vary greatly. Preferably, for example, a 1/4'' thick
layer of biomass, is conveyed at speeds of between about 5 and 100
ft/min (e.g. between about 5 and 100 ft/min, between about 6 and
100 ft/min, between about 7 and 100 ft/min, between about 8 and 100
ft/min, between about 9 and 100 ft/min, between about 10 and 100
ft/min, between about 11 and 100 ft/min, between about 12 and 100
ft/min, between about 13 and 100 ft/min, between about 14 and 100
ft/min, between about 15 and 100 ft/min, between about 20 and 100
ft/min, between about 30 and 100 ft/min, between about 40 and 100
ft/min, between about 2 and 60 ft/min, between about 3 and 60
ft/min, between about 5 and 60 ft/min, between about 6 and 60
ft/min, between about 7 and 60 ft/min, between about 8 and 60
ft/min, between about 9 and 60 ft/min, between about 10 and 60
ft/min, between about 15 and 60 ft/min, between about 20 and 60
ft/min, between about 30 and 60 ft/min, between about 40 and 60
ft/min, between about 2 and 50 ft/min, between about 3 and 50
ft/min, between about 5 and 50 ft/min, between about 6 and 50
ft/min, between about 7 and 50 ft/min, between about 8 and 50
ft/min, between about 9 and 50 ft/min, between about 10 and 50
ft/min, between about 15 and 50 ft/min, between about 20 and 50
ft/min, between about 30 and 50 ft/min, between about 40 and 50
ft/min). It is preferable that the material be conveyed at a
constant rate, for example, to help maintain a constant irradiation
of the material as it passes under the electron beam (e.g., shower,
field).
[0177] The vibratory conveyors described can include screens used
for sieving and sorting materials. Port openings on the side or
bottom of the troughs can be used for sorting, selecting or
removing specific materials, for example, by size or shape. Some
conveyors have counterbalances to reduce the dynamic forces on the
support structure. Some vibratory conveyors are configured as
spiral elevators, are designed to curve around surfaces and/or are
designed to drop material from one conveyor to another (e.g., in a
step, cascade or as a series of steps or a stair). Along with
conveying materials conveyors can be used, by themselves or coupled
with other equipment or systems, for screening, separating,
sorting, classifying, distributing, sizing, inspection, picking,
metal removing, freezing, blending, mixing, orienting, heating,
cooking, drying, dewatering, cleaning, washing, leaching,
quenching, coating, de-dusting and/or feeding. The conveyors can
also include covers (e.g., dust-tight covers), side discharge
gates, bottom discharge gates, special liners (e.g., anti-stick,
stainless steel, rubber, custom steal, and or grooved), divided
troughs, quench pools, screens, perforated plates, detectors (e.g.,
metal detectors), high temperature designs, food grade designs,
heaters, dryers and or coolers. In addition, the trough can be of
various shapes, for example, flat bottomed, vee shaped bottom,
flanged at the top, curved bottom, flat with ridges in any
direction, tubular, half pipe, covered or any combinations of
these. In particular, the conveyors can be coupled with an
irradiation systems and/or equipment.
[0178] The conveyors (e.g., vibratory conveyor) can be made of
corrosion resistant materials. The conveyors can utilize structural
materials that include stainless steel (e.g., 304, 316 stainless
steel, HASTELLOY.RTM. ALLOYS and INCONEL.RTM. Alloys). For example,
HASTELLOY.RTM. Corrosion-Resistant alloys from Hynes (Kokomo, Ind.,
USA) such as HASTELLOY.RTM. B-3.RTM.ALLOY, HASTELLOY.RTM.
HYBRID-BC1.RTM. ALLOY, HASTELLOY.RTM. C-4 ALLOY, HASTELLOY.RTM.
C-22.RTM. ALLOY, HASTELLOY.RTM. C-22HS.RTM. ALLOY, HASTELLOY.RTM.
C-276 ALLOY, HASTELLOY.RTM. C-2000.RTM. ALLOY, HASTELLOY.RTM.
G-30.RTM. ALLOY, HASTELLOY.RTM. G-35.RTM. ALLOY, HASTELLOY.RTM. N
ALLOY and HASTELLOY.RTM. ULTIMET.RTM. alloy.
[0179] The vibratory conveyors can include non-stick release
coatings, for example, TUFFLON.TM. (Dupont, Del., USA). The
vibratory conveyors can also include corrosion resistant coatings.
For example, coatings that can be supplied from Metal Coatings Corp
(Houston, Tex., USA) and others such as Fluoropolymer, XYLAN.RTM.,
Molybdenum Disulfide, Epoxy Phenolic, Phosphate-ferrous metal
coating, Polyurethane-high gloss topcoat for epoxy, inorganic zinc,
Poly Tetrafluoro ethylene, PPS/RYTON.RTM., fluorinated ethylene
propylene, PVDF/DYKOR.RTM., ECTFE/HALAR.RTM. and Ceramic Epoxy
Coating. The coatings can improve resistance to process gases
(e.g., ozone), chemical corrosion, pitting corrosion, galling
corrosion and oxidation.
[0180] Optionally, in addition to the conveying systems described
herein, one or more other conveying systems can be enclosed. 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.
[0181] The enclosed conveyor 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.
[0182] 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.
Other Embodiments
[0183] Any material, processes or processed materials discussed
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
International Application 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.
[0184] 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).
[0185] An optional embodiment for filtering materials described
herein includes utilizing a Rotary Pressure Filter and/or a Vacuum
Belt Filter. The saccharified material is filtered using this
equipment where, in general, the product sugars are separated from
the solids. The equipment provides the means to wash retained
sugars from the filter solids. The filter cake can be used for
energy, utilized for valuable components such as lignin derived
products, or recycled for further bioprocessing.
[0186] FIG. 4A shows a perspective exploded view of a Rotary
Pressure Filter 400. Filter drum 410 rotates continuously in a
pressure-sealed housing 420 at infinitely variable speed, for
example, in the direction indicated by the curved dashed arrows.
The drum is covered with a filter cloth, for example, as previously
described for rotary vacuum drum filtration apparatus. Feedstock
(e.g., saccharified biomass) enters the interior of the drum
through ports (shown in FIGS. 4B-4E) disposed on the bottom of drum
housing. The annular space between drum and housing is sealed to
the sides by stuffing boxes and divided into pressure-tight segment
chambers by separating elements. The surface of the drum consists
of filter cells 430 in fluid connection to drainage pipes 440
through control head 450. The feedstock is forced through the
filter cells, to the drainage pipes and exits as filtered liquid
product at port 414 as indicated by arrow B (e.g., the arrow shows
the flow of a filtered sugar solution derived from the saccharified
material). Arrows A indicate a drying gas (e.g., air, nitrogen,
steam, including super heated steam) that enters through ports 412
as indicated by arrows A (e.g., arrows indicating the flow of the
gas which dries the solids on the surface of the drum while forcing
the liquids through the filter cells 430). Filter cake is removed
from the drum surface and exits through discharge 416.
[0187] Details of how the processing through the pressure filter
are shown in more detail by side view partial cross section FIGS.
4B, 4C, 4D and 4E. FIG. 4B shows a step of inputting the feedstock
and filtering using the filter device. A feedstock (e.g.,
saccharified material) is fed continuously through port 510 as
indicated by the straight arrow C. The material is fed continuously
and under pressure to the filter from below the drum. In the filter
cells, a filter cake 520 forms on the filter elements and is
carried into the flowing segment chambers by drum rotation (e.g.,
the rotation direction as indicated by the curved arrow). The
filtrate drains off the cells through the pipe system, including
pipes 440 to the control head. FIG. 4C shows a step of washing the
filter cake. Optionally, e.g., depending on the application,
washing, extraction or steaming can take place in one or more
stages. As each segment chamber rotates past port 522 a washing
fluid is forced through the cake and into the pipe system as
indicated by the solid arrow D. For example, the washing fluid can
be water, optionally with additives such as anti-foam agents,
chelates, viscosity modified, surfactants and/or pH modifiers
(e.g., acids, bases, buffers). The washing fluid can optionally be
heated or cooled to aid in the extraction process, for example,
steam can be used. The washing fluid is drained through the pipe
system to the control head. Although it can be desirable to extract
as much of the soluble components as possible (e.g., sugars), the
dilution of the components should be considered e.g., it may not be
practical to dilute components excessively. FIG. 4D shows a cake
drying step. As previously discussed a gas such as compressed air,
nitrogen or steam can be made to flow through port 412 so as to dry
the filter cake while forcing fluids into the tubing system and to
the control head. FIG. 4E shows a step of discharging the cake from
the drum surface. Discharging of the filter cake occurs in a
discharge zone that is non-pressurized. The discharge zone can
include a gas-tight hood if required. The cake is discharged by,
for example, back-blowing and optionally, by a movable scraper. The
filter cloth can then be washed. Filter cake 550 is removed through
port 416. A device for cleaning the cake, either continuously or on
demand, can also be included, e.g., washing with a washing fluid,
the fluid composition being as previously described.
[0188] Another optional embodiment for filtering materials
described herein includes utilizing an Indexing Belt Filter (e.g.,
a Vacuum Belt Filter). FIG. 5A shows a front schematic view of an
Indexing Belt Filter 600. This filtration system includes an
endless filter belt 602 (e.g., looped by tensioned rollers). The
filter belt includes or is a filter cloth (e.g., as previously
described for rotary vacuum drum filtering). The feedstock can be
fed continuously or stepwise to the belt. The belt moves in a
stepwise movement in the direction indicated by the arrows. Vacuum
trays 614 are fixed in place on a frame that provides support for
components of the apparatus (e.g., the rollers, the drive motors,
the trays and the filter belt). The filter belt with the feedstock
moves stepwise over the trays. Each time the belt stops, the
filtrate is sucked downwards. Subsequently, the vacuum is shut off,
releasing the filter belt which can be advanced (e.g., indexed or
stepped) again. A filter cake forms on top of the belt and can
undergo further treatment by washing (co-current or
counter-current), re-slurrying, steaming, extraction, vacuum drying
and pressing. The wash filtrates (e.g., sugar water) can be
recovered individually from each vacuum tray and further processed.
As shown and partially described, the filter system can be
segmented into zones or phases wherein different processes occur.
In phase 610 the feedstock is applied to the filter belt, phase 640
includes washing, phase 660 includes a drying step and phase 680 is
a cake discharging step. The details of each step are described
with reference to FIGS. 5B, 5C, 5D and 5E.
[0189] The filter trays 614 are fixed to a frame and do not move
with the belt. The trays are installed beneath the filter belt over
the full length from the feed area 610 to before the cake discharge
area 680. The trays supply a support to the belt but allow liquids
to pass through. For example, the surface in contact with the belt
can include a support grid 619 to allow liquids to pass through.
Located beneath the support grid are filtrate collecting channels
615.
[0190] FIG. 5B shows a step and zone wherein a feedstock 612 (e.g.,
saccharified biomass) is added to the surface of the belt filter
602. Filtration occurs by the action of gravity and optionally
vacuum applied under the belt as it is supported by each tray.
Liquids flow e.g., as shown by the empty arrow through grid surface
619 away from the trays and can be collected. A filter cake 617
forms as a layer on the filter belt and is incrementally carried
forward in the direction shown by the filled arrows once the
initial evacuation step is complete.
[0191] FIG. 5C shows a washing step or zone. In this phase, soluble
components in the filter cake that remain with the solid can be
washed out. For example, sugars can be extracted by applying an
aqueous solution. The solution can be water or water with
additives. For example, additives as described previously such as
anti-foam agents, chelates, viscosity modified, surfactants and/or
pH modifiers (e.g., acids, bases, buffers). The washing fluid can
optionally be heated or cooled to aid in the extraction process,
for example, even steam can be used. The fluid can be poured onto
the filter cake as depicted by 642 or it can be sprayed on (e.g.,
as droplets, a mist or even a vapor) as depicted by 644. Although
it can be desirable to extract as much of the soluble components as
possible (e.g., sugars), practical considerations may include not
to diluting collected components excessively. The washings can be
driven through the trays by a vacuum as in the previous phase. The
washings flow in the direction indicated by the empty arrows and
are collected for further processing (e.g., combined with the first
sugar water from the first phase, recycled and/or concentrated). In
some optional embodiments the washings from the second phase are
re-used for additional washings until a specific concentration of
extracted components is reached (e.g., sugars at least to 1 wt %, 2
wt %, 5 wt %, 10 wt %).
[0192] FIG. 5D shows a step and zone wherein drying can be done by
applying the vacuum to the underside of the belt as previously
described. Optionally, hot air or steaming hoods 662 can be used.
For example, hot steam can be injected through applicator 664.
Optionally, a mechanical means of drying can be utilized. For
example, pressing device 666 can be utilized. Optionally, the
pressing device can be a thermal pressing device, e.g., wherein the
pressing device surface in contact with the filter cake, is heated.
Liquids or fluids (e.g., gases such as vapor) can be made to flow
as indicated by the open arrows and collected for further
processing or recycling as previously discussed.
[0193] FIG. 5E shows a cake discharge and belt cleaning section.
The filter cake is discharged between the discharge rollers 682 and
684. A scraper can be installed 686 that strips off any cake
residue 688 still adhering to the belt at roller 684. The filter
cake 617 and residue 688 can be collected and further processed. A
washing station 690 can wash and/or condition the filter belt
before the belt loops back to the first zone 610.
[0194] Rotary Pressure Filters and Indexing Belt filters can be
purchased from BHS-Sonthofen Inc. (Charlotte, N.C.) and used as
designed or modified. One or more of each of these can be utilized
in the filtering methods described. For example, filtering aids can
be utilized. For example, one or more of each of these can be used
to replace any of the filtering elements described in FIG. 3A, 3B
or 3C. For example RVDF 340, centrifuge 350, screener 360 can be
replaced by a Rotary Pressure filter and/or an Indexing Belt
Filter. Optionally or additionally one or more Rotary Pressure
Filter and/or one or more Indexing Belt Filters can be used in
addition to the filtering elements discussed. For example, an
Indexing Belt Filter can be inserted between the screener 360 and
the distillation 330 described by FIG. 3C, or a Rotary Pressure
Filter can be inserted after the distillation 330 and before the
RVDF 340 described in FIG. 3B.
Flavors, Fragrances and Colorants
[0195] 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), syrups,
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.
[0196] 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.
[0197] 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.
[0198] 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.
[0199] 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.
[0200] 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.
[0201] 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, CITROLATET.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., CYCLEMAXT.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, HERBALIMET.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., LIFFAROMET.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, NECTARATET.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,
SANTALIFFT.TM., SYVERTAL, TERPINEOL, TERPINOLENE 20, TERPINOLENE 90
PQ, TERPINOLENE RECT., TERPINYL ACETATE, TERPINYL ACETATE JAX,
TETRAHYDRO, MUGUOL.RTM., TETRAHYDRO MYRCENOL, TETRAMERAN,
TIMBERSILKT.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
IFRA 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.degree. 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.
[0202] The colorants can be among those listed in the Color 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,
for example, 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-benzenetrio-
l,
16,23-Dihydrodinaphtho[2,3-a:2',3'-i]naphth[2',3':6,7]indolo[2,3-c]carb-
azole-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'-1m)
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-oxoallyl)amino]-2-sulphonatophenyl]ami-
no]-9,10-dihydro-9,10-dioxoanthracene-2-sulphonate (Reactive Blue
69), D&C Blue No. 9, [Phthalocyaninato(2-)]copper and mixtures
of these.
EXAMPLES
Saccharification
[0203] Saccharified batches were produced as described here and
used in the following examples 1 and 2.
[0204] 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.
[0205] The tank was charged with 200 Kg water, 80 Kg of biomass,
and 18 Kg of DUET.TM. Cellulase enzyme. Biomass was corn cob that
had been hammer milled and screened to a size of between 40 and 10
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)2. This combination was heated to 53.degree. C.,
stirred at 180 rpm (1.8 Amp at 460V) for about 24 hours after which
the saccharification was considered completed
Example 1
Centrifuge Followed by Rotory Vacuum Drum Filtration
[0206] Solids were separated from saccharified batches using a
continuous scroll decanter centrifuge with a 12 foot long drum.
Centrifugation was performed immediately after the completion of
saccharification at less than 60.degree. C. Rates of centrifugation
were 30 gallons per minute with solids loading at 15 wt. %. Solids
were free of standing liquid and tested at 50 wt. % (water) on
drying or less. The liquids were used for fermentation with yeast,
producing ethanol. Distillation was used to separate the ethanol
from the other products. The liquids sent to fermentation contained
about 5 wt. % solids.
[0207] A rotary vacuum drum filter (RVDF) was used for filtering
solid residues after the distillation. The 2 feet wide by 2 feet
diameter drum (with approximately 6 square feet of filter cloth)
was pre-coated with 2'' of filter-aid. The feed stream of the
distillation bottoms was 600 liters (5 wt. % solids) in 2 hours and
used less than 1/10.sup.th the filter-aid from the pre-coating. The
average knife advance speed was therefore less than 0.1''/hr. The
filtrate contained less than 0.1 wt % solids (total suspended
solids, TSS). Particles down to about 0.5 um (mean particle size)
were removed. The turbidity was also very low, estimated at below
about 5 NTU.
Example 2
Vibratory Screener Followed by Rotary Vacuum Drum
[0208] A vibratory screener with 60 mesh screens was used to remove
solids from a saccharified material. This method leaves a small
amount of fines in the stream. Solids were about 5 wt. % after this
step. The screened material was fermented and then distilled. The
distillation bottoms were filtered by RVDF under the same operating
conditions as outlined above, rendering a filtered product with
similar solids and turbidity relative to those given above.
[0209] 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.
[0210] 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 (e.g., end
points may be used). When percentages by weight are used herein,
the numerical values reported are relative to the total weight.
[0211] 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.
[0212] 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.
[0213] 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.
* * * * *