U.S. patent application number 13/768747 was filed with the patent office on 2013-08-15 for apparatus and low temperature process for producing dried distillers solubles.
This patent application is currently assigned to GS CLEANTECH CORPORATION. The applicant listed for this patent is GS Cleantech Corporation. Invention is credited to Forrest L. Dahmes, Kevin E. Kreisler, David J. Winsness.
Application Number | 20130206342 13/768747 |
Document ID | / |
Family ID | 47755060 |
Filed Date | 2013-08-15 |
United States Patent
Application |
20130206342 |
Kind Code |
A1 |
Dahmes; Forrest L. ; et
al. |
August 15, 2013 |
APPARATUS AND LOW TEMPERATURE PROCESS FOR PRODUCING DRIED
DISTILLERS SOLUBLES
Abstract
Low temperature process and apparatus generally includes
separating whole stillage into thin stillage and wet distillers
grains, wherein the thin stillage comprises water soluble proteins
in an amount greater than the wet distillers grains, and wherein
the wet distillers grains has a higher solid content than the thin
stillage; atomizing the thin stillage at an elevated temperature to
remove at least a portion of moisture in the thin stillage and form
particles and granules of the thin stillage; and removing
additional moisture from the particles and granules in a fluidized
bed to form dried distillers solubles. The apparatus includes an
atomization section and a fluidized bed section configured to dry
the thin stillage.
Inventors: |
Dahmes; Forrest L.; (Hawick,
MN) ; Winsness; David J.; (Alpharetta, GA) ;
Kreisler; Kevin E.; (Mount Arlington, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GS Cleantech Corporation; |
|
|
US |
|
|
Assignee: |
GS CLEANTECH CORPORATION
New York
NY
|
Family ID: |
47755060 |
Appl. No.: |
13/768747 |
Filed: |
February 15, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61599215 |
Feb 15, 2012 |
|
|
|
61614862 |
Mar 23, 2012 |
|
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Current U.S.
Class: |
159/4.01 ;
159/48.1 |
Current CPC
Class: |
C08J 11/04 20130101;
C09J 189/04 20130101; C08H 99/00 20130101; Y02E 50/10 20130101;
C08L 97/02 20130101; B01J 2/06 20130101; C08B 37/00 20130101; C08L
101/16 20130101; Y02E 50/17 20130101; C08H 1/00 20130101; B01J 2/04
20130101; C12F 3/10 20130101; B01D 1/18 20130101; C07K 14/415
20130101 |
Class at
Publication: |
159/4.01 ;
159/48.1 |
International
Class: |
B01D 1/18 20060101
B01D001/18 |
Claims
1. A process of forming dried distiller solubles, the process
comprising: separating whole stillage into thin stillage and wet
distillers grains, wherein the thin stillage comprises water
soluble proteins in an amount greater than the wet distillers
grains, and wherein the wet distillers grains has a higher solid
content than the thin stillage; atomizing the thin stillage at an
elevated temperature to remove at least a portion of moisture in
the thin stillage and form particles and granules of the thin
stillage; and removing additional moisture from the particles and
granules in a fluidized bed to form dried distillers solubles.
2. The process of claim 1, wherein the thin stillage is subject to
evaporation prior to spraying to reduce moisture content and form a
concentrated thin stillage.
3. The process of claim 1, wherein the particles and granules are
heated to a temperature less than about 200.degree. F.
4. The process of claim 1, further comprising kneading the dried
distillers solubles.
5. The process of claim 4, wherein kneading is provided by roller
mills, mixing mills, or extrusion processing.
6. The process of claim 1, further comprising extruding the dry
distillers solubles at a temperature less than 200.degree. F.
7. The process of claim 1, further comprising dry mixing at least
one additive with the kneaded dried distillers solubles.
8. The process of claim 1, further comprising subjecting the whole
stillage, the thin stillage, concentrated thin stillage and/or the
dried distillers solubles to an oil extraction process that removes
at least a portion of the oil contained therein.
9. The process of claim 1, further comprising wet mixing at least
one additive to the whole stillage or the thin stillage.
10. The process of claim 1, wherein the moisture content is greater
than 3 weight percent to less than 20 weight percent.
11. An apparatus for forming dried distillers solubles from a
corn-to-ethanol facility, comprising: an atomization section
comprising a housing including a top wall and sidewalls extending
therefrom, the top wall and/or sidewalls including an exhaust, and
an atomization nozzle within the housing; a fluidized bed section
comprising an elongated housing having a open end fluidly coupled
with the atomization chamber and configured for receiving atomized
condensed distillers solubles from the atomization nozzle, a
horizontally disposed conveyor belt disposed on a fluidized bed for
rotatably carrying the received atomized condensed distillers
soluble to a discharge end in the housing, the fluidized bed
including a perforated upper surface, a non-perforated lower
surface in fluid communication with a fluidized medium, and
non-perforated sidewalls extending therebetween, wherein the
fluidized bed is configured to fluidly dry the atomized condensed
distillers solubles with the fluidized medium to form dried
distillers solubles at the discharge end; and a source of condensed
distillers solubles and a compressed gas fluidly coupled to the
atomization nozzle.
12. The apparatus of claim 11, wherein the fluidized bed includes
at least two zones, wherein the fluidizing medium in each zone is
at a different temperature.
13. The apparatus of claim 11, wherein the fluidized bed includes
at least two zones, wherein the fluidizing medium is different in
at least one of the at least two zones.
14. The apparatus of claim 11, wherein the at least one zone that
is proximate to the discharge end is at a lower temperature than
the other zones.
15. The apparatus of claim 11, wherein the conveyor belt further
comprises drag bars spaced apart on a surface thereof in operative
communication with the fluidized bed such that as the conveyor belt
rotates the drag bars push the atomized condensed distillers
solubles along the perforated upper surface to the discharge
end.
16. The apparatus of claim 11, wherein the source of condensed
distillers solubles is from a multistage evaporator in the
corn-to-ethanol facility.
17. The apparatus of claim 11, wherein the source of condensed
distillers solubles is a holding tank.
18. The apparatus of claim 11, wherein the atomization section is
configured to expose the source to a temperature less than
300.degree. F. and the fluidized section is configured to cool the
atomized condensed distillers solubles so as to form the dried
distillers solubles at the discharge end.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of the
U.S. Provisional Patent Application Nos. 61/599,215, filed on Feb.
15, 2012 and 61/614,862 filed Mar. 23, 2012, which are fully
incorporated herein by reference.
BACKGROUND
[0002] The present disclosure generally relates to an apparatus and
low temperature process for producing dried distillers solubles
from byproducts produced in a corn-to-ethanol fermentation
facility.
[0003] Because of its relatively low investment and operational
requirements, dry milling has become the primary method for
converting starch within corn to ethanol. In the dry milling
process, corn is first screened and ground to a flour. The
resulting flour is combined with water and the starch within the
corn is conventionally hydrolyzed into sugar by liquefaction and
saccharification. The mixture is then fermented with yeast to
convert the sugar into ethanol and carbon dioxide. About 30% of the
mass of each kernel of corn accepted by corn ethanol producers is
converted into ethanol in this manner. The output of fermentation,
a mixture of ethanol, water, protein, carbohydrates, fat, minerals,
solids and other unfermented components, is then distilled to boil
off ethanol for recovery, purification and sale, leaving the
remainder of the mixture in the bottom of the distillation
stage.
[0004] The remainder at the bottom of the distillation stage is
referred to as whole stillage (WS) and is typically subjected to a
press or centrifugation process to separate the coarse solids from
the liquid. The liquid fraction is commonly referred to as
distillers solubles or thin stillage (TS). TS is frequently
concentrated in an evaporator to become condensed distillers
solubles (CDS), which is also commonly referred to as syrup. The
coarse solids, or wet cake, collected from the centrifuge or press
is known as wet distillers grains (WDG). Drying the WDG produces
dried distillers grains (DDG). The WDG can be combined with the CDS
to form what is commonly referred to as wet distillers grains with
solubles (WDGS), which can then be dried to form dried distillers
grains with solubles (DDGS). The DDG or DDGS typically has a
moisture content less than 15% by weight.
[0005] In some instances, the CDS is subjected to a high
temperature drying process to form dried distillers solubles, which
reportedly has been used as a thermoplastic additive with a metal
oxide and fiber in the preparation of extruded articles.
[0006] In other instances, the partially concentrated thin stillage
or condensed distillers solubles, prior to being combined with the
wet distillers grains, is subjected to a corn oil extraction
process to remove at least a portion of the oil contained therein.
The extracted crude corn oil can be used as a feedstock for the
production of biodiesel and other products. The remaining condensed
distillers solubles with at least a portion of the oil removed is
then typically combined with the wet distillers grains to form WDGS
and further dried as DDGS for use as animal feed. Exemplary corn
oil extraction processes are disclosed in U.S. Pat. Nos. 7,601,858,
7,608,729, 8,008,516, and 8,008,517, all of which are incorporated
by reference in their entireties.
[0007] The corn fermentation solids have been used to form
biopolymer compositions. As noted above, the solid fraction
includes the portion of solids deriving from the whole stillage.
For example, U.S. Pat. No. 7,625,961 to Riebel discloses
compositions that generally include the fermentation solids at 0.1
to 95% by weight and a thermoactive material at 0.1 to 95% by
weight. The thermoactive material is selected to have a melting
point less than the fermentation solid and generally serves as a
binder in which the fermentation material can be embedded.
Exemplary thermoactive materials include thermoplastics, thermoset
materials, resins and the like. The fermentation solids disclosed
by Riebel are generally selected from the group consisting of
fermented protein solid, distiller's dried grain, distiller's dried
grain-200, distiller's dried corn, distiller's dried fractionated
corn, distiller's dried starch root crop, distiller's dried tuber,
distiller's dried root, distiller's dried cereal grain, distiller's
dried wheat, distiller's dried rye, distiller's dried rice,
distiller's dried millet, distiller's dried oats, distiller's dried
potato, wet cake, and solvent washed wet cake.
[0008] The liquid fraction, which contains water soluble components
such as water soluble protein, may be further processed, e.g.,
concentration, oil extraction, and the like. The liquid fraction is
then typically added back to the DDG to form DDGS, i.e., dried
distillers grains with solubles.
[0009] Thus, it would be desirable for a more robust renewable
material. Accordingly, it is to solving this and other needs the
present disclosure is directed.
BRIEF SUMMARY
[0010] Disclosed herein are an apparatus and low temperature
process for forming dried distillers solubles from byproducts
produced in a corn to ethanol facility.
[0011] In one embodiment, the process of forming dried distiller
solubles comprises separating whole stillage into thin stillage and
wet distillers grains, wherein the thin stillage comprises water
soluble proteins in an amount greater than the wet distillers
grains, and wherein the wet distillers grains has a higher solid
content than the thin stillage; and atomizing the thin stillage at
an elevated temperature to remove at least a portion of moisture in
the thin stillage and form particles and granules of the thin
stillage; removing additional moisture from the particles and
granules in a fluidized bed to form dried distillers solubles.
[0012] The apparatus for forming dried distillers solubles from a
corn-to-ethanol facility comprises an atomization section
comprising a housing including a top wall and sidewalls extending
therefrom, the top wall and/or sidewalls including an exhaust, and
an atomization nozzle within the housing; a fluidized bed section
comprising an elongated housing having a open end fluidly coupled
with the atomization chamber and configured for receiving atomized
condensed distillers solubles from the atomization nozzle, a
horizontally disposed conveyor belt disposed on a fluidized bed for
rotatably carrying the received atomized condensed distillers
soluble to a discharge end in the housing, the fluidized bed
including a perforated upper surface, a non-perforated lower
surface in fluid communication with a fluidized medium, and
non-perforated sidewalls extending therebetween, wherein the
fluidized bed is configured to fluidly dry the atomized condensed
distillers solubles with the fluidized medium to form dried
distillers solubles at the discharge end; and a source of condensed
distillers solubles and a compressed gas fluidly coupled to the
atomization nozzle.
[0013] The disclosure may be understood more readily by reference
to the following detailed description of the various features of
the disclosure and the examples included therein.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0014] Referring now to the FIGURE wherein the like elements are
numbered alike:
[0015] The FIGURE illustrates an exemplary drying apparatus for
forming the dried distillers solubles in accordance with the
present disclosure.
DETAILED DESCRIPTION
[0016] The present disclosure is generally directed to dried
distillers solubles (DDS) based biopolymers, processes for making
the same, and articles of manufacture. As used herein, the DDS is
obtained from a specific byproduct feedstream resulting from
fermentation of biomass such as corn to produce whole stillage. As
noted above, the byproduct of fermentation, i.e., whole stillage,
is generally separated into a solids fraction and a liquid
fraction. It is the liquid fraction, also referred to as thin
stillage, which is used to form the DDS.
[0017] The solids fraction, also referred to as the wet cake or wet
distillers grains (WDG), is generally utilized to form the dried
distillers grains (DDG), which has a markedly different composition
than that of DDS. For example, the CDS precursor to DDS includes
water soluble components such as water soluble proteins that form
the basis of the biopolymer properties whereas the WDG fraction
generally lacks such soluble constituents.
[0018] Advantageously, the biopolymers formed from the DDS are
elastomeric, biodegradable, and can be made without the need for
additional binders. Further, the DDS are subjected to a multistep
low temperature drying process to form particles and granules. This
low temperature process provides DDS in a powder and/or granular
form with a moisture content of about 3% to about 20% by weight,
and in other embodiments, about 5% to about 12% by weight. In some
embodiment, the DDS can be dried to greater than about 1 percent
moisture to less than 20 percent by weight. The biopolymers and
articles of manufacture produced therefrom can be formed entirely
from the DDS as may be desired for some applications. The DDS can
be kneaded by various mechanical means as desired. Optionally, the
DDS can be admixed with various other components depending on the
intended application.
[0019] In one embodiment, prior to its use as a biopolymer, the DDS
is first subjected to an oil extraction process that removes at
least a portion of the oil contained therein. The particular oil
extraction process is not intended to be limited and can occur at
any stage of the process for forming the DDS. For example, the
whole stillage, thin stillage, concentrated thin stillage (also
referred to as condensed distillers solubles or CDS), or the DDS
itself may be subjected to an oil extraction process. Exemplary oil
extraction processes are disclosed in U.S. Pat. No. 8,168,037 to
Winsness et al., incorporated herein by reference in its
entirety.
[0020] The DDS materials derive exclusively from co-products of
fermentation and, as noted above, can be comprised of water-soluble
proteins, among other constituents. The use of DDS obtained from
the liquid fraction overcomes many of the problems noted in the
prior art as it relates to biopolymers in general and as it relates
to the prior art's use of dried distillers grains with or without
solubles, i.e., DDG or DDGS. Moreover, because of the uniqueness of
the DDS, the properties can be readily manipulated by additives
and/or by compositional changes as a function of processing. With
regard to compositional changes, because the DDS is ultimately
obtained from whole stillage (i.e., the residue remaining after
ethanol distillation), it should be apparent that modification,
physical or chemical, of the final biopolymer properties can be
made to any one of the product streams upstream from the DDS as
well as on the DDS itself. In another embodiment, the upstream
treatment can include the removal or partial removal of starch or
carbohydrates that remain in the non-fermented byproduct of the
corn-to-ethanol fermentation process. These methods can include but
are not limited to CO.sub.2 extraction, an additional fermentation
step, etc. Furthermore, the upstream treatment can include
filtration, membrane filtration or centrifugation technologies to
isolate and reduce additional components within such as but not
limited to suspended or selected dissolved solids.
[0021] The DDS resultant material by itself is generally in a
powder and/or granular form and, in some embodiments, can be used
neat as the biopolymer. For example, heat and pressure can be used
to form a profiled article of manufacture using DDS as a stand
alone material. By way of example, the DDS in the polymer and/or
granular form can be extruded with a single or twin screw extruder,
for example, to form a profiled article of manufacture.
Alternatively, the biopolymer can be compounded with other polymers
and/or monomers to tailor the desired properties of the biopolymer
blend to the desired end use. Still further, the DDS biopolymer can
be functionalized directly or upstream in the process of making the
DDS, wherein the particular functionalization is selected based on
the desired properties of the article of manufacture.
[0022] The resultant DDS material can also be used as a resin
extender, wherein the DDS is blended with another polymer to lower
its cost and provide various functional advantages in the final
blend.
[0023] The process for forming the DDS generally includes
separating the whole stillage into a solids fraction and a liquids
fraction; and drying the liquid fraction, i.e., thin stillage or
CDS, to form the DDS. In the corn fermentation process, the liquid
fraction that is first obtained after distillation and after
separation of the whole stillage residue, i.e., the thin stillage
feedstream, is typically first fed to an evaporator, e.g., a
multistage evaporator, to remove a portion of the water contained
therein to produce condensed distillers solubles (CDS), also
referred to by those in the art as thin stillage concentrate. In
ethanol production facilities, the evaporation temperatures for the
evaporators are typically about 100 to 230.degree. F. and more
typically about 110 to 200.degree. F. The CDS is then fed to a
drying apparatus to form the DDS. However, in some embodiments, it
may be desirable to form the DDS directly from the thin stillage.
In such embodiments, or where CDS is first formed by evaporation of
the thin stillage, it may be desirable in some applications to
remove at least a portion of the oil, water and/or other
constituents contained therein prior to drying to form the DDS. The
amount of oil and/or other constituents removed can be used to
tailor the biopolymer properties. In addition to the production of
DDS and its subsequent use as a biopolymer, the extracted corn oil
itself can be used for various applications including, but not
limited to, production of biodiesel, thereby transforming what was
previously considered as a low value product into a significant
revenue stream for ethanol plant operator.
[0024] Once a portion of the oil is removed from the CDS, in some
applications it may be desired to further concentrate the CDS and
subject this further concentrated CDS to an additional oil or water
extraction process to remove additional oil or water.
Alternatively, this concentrated CDS material may be dried in a
drier apparatus to produce the DDS. Again, doing so can be used to
manipulate the final biopolymer properties as may be desired for
different applications.
[0025] The drying process applied to the liquid fraction generally
includes a fluidized bed apparatus configured to heat CDS (or thin
stillage) to a temperature less than 300.degree. F. in most
embodiments, less than 250.degree. F. in other embodiments, and
less than 200.degree. F. in still other embodiments. In one
embodiment, the process generally includes spraying or conducting
CDS through one or more nozzles and subjecting the resultant output
to a flow of heated gases within a chamber to evaporate at least a
portion of the moisture from the CDS and form discrete particles
and granules. The discrete particles and granules are then carried
from the chamber by means of a fluidized bed to facilitate
additional drying and/or cooling that may include additional
moisture removal. The fluidized bed includes a perforated surface
in fluid communication with a fluidizing medium. The bed may
include a single or plurality of zones, where the first zone
introduces a heated inert fluidizing medium and additional zones
facilitates cooling of the particles and/or granules prior to
discharge from the apparatus. An exemplary apparatus is provided in
the FIGURE. The perforated surface of the fluidized bed can be a
fixed bed, perforated moving conveyor, a perforated vibrating bed,
a vibrating perforated moving conveyor or other.
[0026] Referring now to the FIGURE, the exemplary fluidized bed
apparatus generally designated by reference numeral 10 includes an
atomization section 12 and a fluidized bed section 14. The
atomization section 12 includes an elongated housing having a top
portion 16 and a bottom portion 18. The bottom portion 18 is
fluidly connected to the fluidized bed section 14. The top portion
16 includes an exhaust conduit 20 generally positioned to carry
exhaust gases from the atomization section 12. The exhaust gases,
which may be at an elevated temperature and may contain vaporized
water, solvent and/or other residuals, may be further treated or
discharged to the atmosphere, or the thermal energy contained
therein may be used in additional thermal processes. For example,
the exhaust could be fed to a heat exchanger to minimize the energy
requirements associated with operating the fluidized beds, the
ethanol production facility, and the like. Optionally, air adjusted
weirs and/or baffles (not shown) can be additionally incorporated
to manage residence times.
[0027] The atomization section 12 further includes at least one
inlet 22 for introducing CDS 30 into the drying chamber via conduit
24. The inlet 22 is fluidly connected to an atomization nozzle 26
for atomizing the CDS 30 within the drying chamber. A source of
compressed gas 27 is in fluid communication with the atomization
nozzle 26. The compressed gas can be fed into conduit 24 or may be
separately provided via a separate conduit to the atomization
nozzle 26. A positive displacement pump 28 may be employed to pump
the CDS 30 to the atomization nozzle 26. The CDS 30 source may be
plumbed directly from the fermentation facility, e.g., following
evaporation, or may be stored within a holding tank as may be
desired for some applications.
[0028] The fluidized bed section 14 includes an elongated housing
32 having an opening in fluid communication with the drying
chamber. A horizontally disposed conveyor belt 34 may be used and
if so, is seated within the fluidized bed section 14. In one
embodiment, the conveyor belt 34 further include drag bars 35
spaced apart on a surface thereof in operative communication with a
fluidized bed 14 such that as the conveyor belt 34 rotates, the
drag bars 35 push the DDS (dried CDS) to a discharge end 38.
[0029] The discharge end 38 can be configured for product
collection or may be configured to provide the discharged material
back to the drying chamber or the fluid bed section.
[0030] The fluidized bed 36 includes a perforated top surface 40 a
non-perforated bottom surface and sidewalls extending therefrom to
the perforated top surface 40. The fluidized bed 35 is in fluid
communication with one or more inert fluidized mediums, two of
which are shown, e.g., 42, 44. The bed includes at least one zone,
two of which are shown: zones 46, and 48. Zone 46 is distally
positioned from the discharge outlet and provides a fluidized
medium to the particles and granules carried by the conveyor belt
34 or moving perforated bed. The zone 48 is proximate to the
discharge outlet and provides inert fluidized medium that is
generally at a temperature less than the first zone but in some
embodiments it may be desired to be to cooler. Each additional zone
intermediate zone 48 and the discharge outlet 38 can be configured
to provide a reduced temperature relative to an adjacent zone so
that the particles and granules are at about room temperature upon
discharge from the discharge outlet 38 as may be desired for some
facilities. Optionally, the fluid bed zone(s) may be configured to
provide cooling, wherein the predominant drying of CDS can occur in
the atomization section. In another embodiment, the perforated
surface 40 is a belt conveyor such that it conveys the pressure
sensitive material while drying and/or cooling the particles and
granules. There may be multiple zones within this conveyor and
sealing surfaces or close tolerances within to minimize the air
loss between the moving perforated conveyor, the side walls and/or
the zone(s).
[0031] The apparatus 10 can be operated in batch or continuous
fashion, and can incorporate one or more devices for accomplishing
thermal treatment apart or in combination with that discussed
above, e.g., convection, conduction and/or radiation, in sequence
and/or concurrently. Likewise, the inert drying gases and fluidized
bed mediums can be metered to precisely control intermediate
temperature, residence time and other relevant process variables
such that, for example, moisture is removed while avoiding
undesirable particle deformation or reactions.
[0032] In one embodiment, the drying process is configured to
provide the DDS in a powder and/or granular form with a moisture
content of about 3 to about 20% by weight, and in other
embodiments, about 5 to about 12% by weight. The material can then
be kneaded by various mechanical means as may be desired, e.g.,
roller mills, mixing mills, and extrusion processing. The DDS is
elastomeric and partially or fully water soluble absent addition of
additional additives, e.g., crosslinkers, vulcanizing agents, and
the like. The various additives can be added by wet mixing prior to
the drying process or dry mixing with the kneaded material.
[0033] In other embodiments, one or more of the sources such as
thin stillage, thin stillage concentrate, partially de-oiled thin
stillage or partially de-oiled thin stillage concentrate can be
homogenized by subjecting the source to high shear. Shear can be
produced through the use of a high pressure pump and a fixed or
adjustable orifice but other devices can be used to create the same
effect as will be appreciated by those skilled in the art. This
process advantageously aides in milling the insoluble fractions to
a smaller size as well as creating uniform product. In another
embodiment, the residual starch and other carbohydrates that were
not converted to ethanol and remain in the byproduct feed stream
can be removed using known techniques such as CO.sub.2 extraction,
an additional fermentation step, and the like.
[0034] Advantageously, the drying apparatus provides a much less
thermally aggressive environment for drying the CDS to form DDS
granules. As previously discussed, DDS is obtained from the liquid
fraction of the separated whole stillage. Relative to the solids
fraction, i.e., wet cake or wet distiller grains, the liquid
fraction contains a significantly higher percentage of water
soluble components, e.g., water soluble proteins. Condensed
distillers solubles generally are more than 20% dissolved solids
and less than 80% suspended solids. In other embodiments, the
percentage of dissolved solids in the CDS is more than 40% of the
total solids in the CDS/DDS stream. In still other embodiments, the
percentage of dissolved solids in the CDS is more than 60% of the
total solids in the CDS/DDS stream.
[0035] Constituent proteins and carbohydrates can form insoluble
compounds (Maillard or browning products) when exposed to high
temperatures in the presence of moisture. Moreover, glutelin, which
comprises about 40% of the protein in corn, are known to form
disulfide bonds and crosslink with themselves and other proteins at
elevated temperatures, a result that can be attributed to oxidation
of constituent sulfhydryl groups to disulfides. The functionality
of the DDS can also be impaired with too much heat, for example, by
unwanted denaturation. Such outcomes can be decreased or avoided by
minimizing and controlling the application of heat in the manner of
the present invention.
[0036] Alternatively, the drying apparatus may be configured to
supplement the convective processes with conductive processes, such
as by incorporating an induction heater or intercooler into the
base of a fluid bed. Emissive methods can also be incorporated,
such as by adding infrared energy emitters into the housing walls,
or by adding a zone in which the feed material is treated by
electromagnetic radiation at wavelengths, intensities and times
sufficient to gently heat the interior of particles to enable more
efficient, lower temperature convection while avoiding excessive
surface dehydration and degradation, or other adverse reactions
that could impair functionality.
[0037] By way of a further example, any of the foregoing thermal
treatment methods could optionally involve introduction of one or
more additives, which may include liquid feedstream or any
co-product from a prior or subsequent stage of this invention or
the fermentation facility, during any stage of thermal treatment to
regulate the characteristics as desired to, for example, prevent
degradation or otherwise render the resulting DDS suitable for
further processing and/or its anticipated end use.
[0038] The thermal treatment processes described above may also be
utilized to facilitate targeted reactions, such as
functionalization, polymerization, crosslinking and the like, as
may be necessary to condition the DDS for its intended end use.
[0039] The CDS without oil extraction or with at least a portion of
the oil (i.e., fat) removed can be dried in the fluidized bed
drying apparatus to form the DDS. Table 1 provides a general
comparison on a dry matter basis of a CDS composition without oil
extraction and a CDS composition with at least a portion of the oil
removed (referred to as "CDS-F"). Reference to CDS-F is not
intended to infer that oil is completely removed from the dried
distillers solubles. In some embodiments, it may be beneficial to
subject the CDS to multiple oil and/or water extraction steps to
further decrease and manipulate the amount of oil and/or water
contained in the DDS product material. In most embodiments, the oil
content in the DDS product material is from 3 to 15% by weight
although higher or lower amounts of oil may be desired in certain
applications
TABLE-US-00001 TABLE 1 CDS CDS-F Protein (%) 18 21 Fat (%) 20 7
Carbohydrates (%) 48 56 Ash (%) 14 16 Total (%) 100 100
[0040] As demonstrated in Table 1, the amount of oil can easily be
varied.
[0041] In a similar manner, the other constituents defining the DDS
composition can be varied. For example, thin stillage or CDS can be
treated to remove a portion of the carbohydrates and/or a portion
of the low molecular weight proteins. Alternatively, the DDS can be
treated to modify one or more of the constituents within the
composition. For example, the proteins and/or carbohydrates can be
functionalized with different materials to provide further
manipulation of the biopolymer properties. By way of example,
protein modifications can include, for example, treating proteins
with an acid, base or other agent that alters the structure of one
or more of the amino acid side chains, which, in turn, alters the
character of the protein and/or amino acids. The net charge carried
by protein molecules is of significance presently since it affects
the behavior and functionality of the molecules. For example, the
high glutamine content of prolamines provides a means for
manipulating the charge characteristics of the protein by
deamidation, thereby providing a wide range of hydrophobicity. In
one embodiment, deamidation involves mild acid catalyzed
deamidation at a pH of about 1 at temperatures from about
25.degree. C. to about 65.degree. C. for a period of time
sufficient to accomplish the desired level of deamidation. In some
embodiments, acids that form stable dispersions and are useful
within these classes include, without limitation, lactic acid,
citric acid, malonic acid, phosphoric acid, fumaric acid, maleic
acid, maleic anhydride, maleated propylenes, glutaric acid,
transaconitic acid, acetic acid, propionic acid, sorbic acid,
cysteine and glycyl glycine. In one embodiment, lactic acid in the
form of polylactic acid is used. In another embodiment, maleated
propylenes, such as G-3003 and G-3015 manufactured by Eastman
chemicals are used.
[0042] The thin stillage and CDS feedstreams have conventionally
been viewed as low-value by-products, i.e., waste products.
Problematically, the chemical and physical characteristics of CDS
adversely affect (and dilute the value of) wet distillers grains
when combined therewith. The resulting product stream, i.e., the
precursor to DDGS, has reduced protein content and is stickier and
less tolerant to spoilage than it would be without addition of CDS
following evaporation. Consequently, producers have to burn more
fossil fuel-derived natural gas to dry DDGS longer than would
otherwise be required in order to vaporize more water and to avoid
handling and spoilage issues. Low moisture content translates
directly into extended storage life. Producers have generally had
little choice but to follow the standard industry practice of
combining CDS with wet distillers grains (WDG) prior to drying for
the want of an economically and technically feasible alternative.
An aspect of this disclosure is to provide such an alternative and
empower producers to reduce these inefficiencies by diverting and
separately processing CDS. As a result, the WDG does not require
the extended drying times since spoilage as a function of moisture
content is less of a concern.
[0043] Thin stillage and its more concentrated CDS form are
generally comprised of water, protein, fat, carbohydrates, ash, and
relatively minor amounts of other fermentation byproducts. At least
some of the protein in the feedstream has been hydrolyzed as a
function of the fermentation process conditions and is
water-soluble. The fat (oil) is substantially comprised of
glycerides and is present in a free, bound and/or emulsified state.
The carbohydrate fraction is further comprised of various sugars,
partially-hydrolyzed starch, and insoluble polysaccharides
(cellulose, hemicellulose and lignin). Ash includes residual
minerals. Fermentation byproducts include glycerol, lactic acid,
acetic acid, yeast, and the like.
[0044] By the time CDS exits the evaporators, its protein and other
constituents have changed significantly due to continuous treatment
during the fermentation process with hot water, enzymes, caustic,
acid, urea and/or other chemicals, at times under pressure and/or
vacuum, for more than two days. Many of these process conditions
are severe and are generally known to facilitate at least some
degree of hydrolysis, denaturation and other presently favorable
reactions and reactants.
[0045] By way of example, ethanol facilities using the method
taught by Winsness in U.S. patent application Ser. No. 11/908,891
incorporated herein by reference in its entirety, iteratively wash
the whole stillage with at least a portion of the thin stillage
after initial separation of whole stillage into wet distillers
grains and thin stillage. This step increases the content of lower
density, low molecular weight and soluble components in the thin
stillage to enhance derivative co-product value, e.g., DDS.
Moreover, as disclosed by Winsness, fat removal efficiencies can be
optionally increased by chemical addition and/or by increasing
temperature and/or concentrated thin stillage or CDS residence time
at targeted temperatures. Using such methods, CDS might be held at
an elevated temperature for an extended period of time at a pH of,
for example, 3.5 to 4.5, before removing at least some fat (oil)
and directing the CDS for final evaporation.
[0046] The DDS or any of the upstream intermediate product
feedstreams including, but not limited to, whole stillage, thin
stillage, condensed distillers solubles, defatted condensed
distillers soluble, and the like, can comprise at least another
component, to manipulate the properties of the biopolymer such as,
but not limited to, improving and/or controlling the viscosity,
shelf-life, and stability. Non-limiting examples of additional
components include tackifiers, plasticizers (plasticizing oils or
extender oils), waxes, antioxidants, UV stabilizers, colorants or
pigments, fillers, flow aids, biocides, lubricants, water, oil,
coupling agents, crosslinking agents, surfactants, catalysts
solvents, hydrolyzing agents, and combinations thereof.
[0047] In further embodiments, the DDS and/or DDS derivative or any
of the upstream product feedstreams disclosed herein optionally can
comprise or incorporate a plasticizer or plasticizing oil or an
extender oil that may reduce viscosity and/or improve extrusion
properties. Any plasticizer known to a person of ordinary skill in
the art may be used in the adhesion composition disclosed herein.
Non-limiting examples of plasticizers include olefin oligomers, low
molecular weight polyolefins such as liquid polybutene, phthalates,
mineral oils such as naphthenic, paraffinic, or hydrogenated
(white) oils (e.g. Kaydol oil), vegetable and animal oil and their
derivatives, petroleum derived oils, and combinations thereof. In
some embodiments, the plasticizers include polypropylene,
polybutene, hydrogenated polyisoprene, hydrogenated polybutadiene,
polypiperylene and copolymers of piperylene and isoprene, and the
like having average molecular weights between about 350 and about
10,000. In other embodiments, the plasticizers include glyceryl
esters of the usual fatty acids and polymerization products
thereof.
[0048] In some embodiments, a suitable insoluble plasticizer may be
selected from the group which includes dipropylene glycol
dibenzoate, pentaerythritol tetrabenzoate; polyethylene glycol
400-di-2-ethylhexoate; 2-ethylhexyl diphenyl phosphate; butyl
benzyl phthalate, dibutyl phthalate, dioctyl phthalate, various
substituted citrates, and glycerates.
[0049] In further embodiments, the DDS and/or DDS derivative or any
of the upstream product feedstreams disclosed herein optionally can
comprise a wax that may reduce the melt viscosity in addition to
reducing costs. Any wax known to a person of ordinary skill in the
art can be used in the adhesion composition disclosed herein.
Non-limiting examples of suitable waxes include petroleum waxes,
polyolefin waxes such as low molecular weight polyethylene or
polypropylene, synthetic waxes, paraffin and microcrystalline waxes
having melting points from about 55 to about 110.degree. C.,
Fischer-Tropsch waxes and combinations thereof. In some
embodiments, the wax is a low molecular weight polyethylene
homopolymer or interpolymer having a number average molecular
weight of about 400 to about 6,000 g/mole.
[0050] In further embodiments, the DDS and/or DDS derivative or any
of the upstream product feedstreams disclosed herein optionally can
comprise an antioxidant or a stabilizer. Any antioxidant known to a
person of ordinary skill in the art may be used in the adhesion
composition disclosed herein. Non-limiting examples of suitable
antioxidants include amine-based antioxidants such as alkyl
diphenylamines, phenyl-.alpha.-naphthylamine, alkyl or aralkyl
substituted phenyl-.alpha.-naphthylamine, alkylated p-phenylene
diamines, tetramethyl-diaminodiphenylamine and the like; and
hindered phenol compounds such as 2,6-di-t-butyl-4-methylphenol;
1,3,5-trimethyl-2,4,6-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)benzene;
tetrakis (methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane
(e.g., IRGANOX.TM. 1010, from Ciba Geigy, N.Y.);
octadecyl-3,5-di-t-butyl-4-hydroxycinnamate (e.g., IRGANOX.TM.
1076, commercially available from Ciba Geigy) and combinations
thereof.
[0051] In further embodiments, the DDS and/or DDS derivative or any
of the upstream product feedstreams disclosed herein optionally can
comprise an UV stabilizer that may prevent or reduce the
degradation of the compositions by UV radiation. Any UV stabilizer
known to a person of ordinary skill in the art may be used in the
adhesion composition disclosed herein. Non-limiting examples of
suitable UV stabilizers include benzophenones, benzotriazoles, aryl
esters, oxanilides, acrylic esters, formamidine, carbon black,
hindered amines, nickel quenchers, hindered amines, phenolic
antioxidants, metallic salts, zinc compounds and combinations
thereof.
[0052] In further embodiments, the DDS and/or DDS derivative or any
of the upstream product feedstreams disclosed herein optionally can
comprise a colorant or pigment. Any colorant or pigment known to a
person of ordinary skill in the art may be used in the adhesion
composition disclosed herein. Non-limiting examples of suitable
colorants or pigments include inorganic pigments such as titanium
dioxide and carbon black, phthalocyanine pigments, and other
organic pigments.
[0053] In further embodiments, the DDS and/or DDS derivative or any
of the upstream product feedstreams disclosed herein optionally can
comprise a filler. Any filler known to a person of ordinary skill
in the art may be used in the adhesion composition disclosed
herein. Non-limiting examples of suitable fillers include sand,
talc, dolomite, calcium carbonate, clay, silica, mica,
wollastonite, feldspar, aluminum silicate, alumina, hydrated
alumina, glass bead, glass microsphere, ceramic microsphere,
thermoplastic microsphere, barite, wood flour, magnesium carbonate,
calcium hydroxide, calcium oxide, magnesium oxide, aluminum oxide,
silicon oxide, iron oxide, boron nitride, titanium oxide, talc,
pyrophyllite clay, silicate pigment, polishing powder, mica,
sericite, bentonite, pearlite, zeolite, fluorite, dolomite, quick
lime, slaked lime, kaolin, chlorite, diatomaceous earth, soda ash,
and combinations thereof.
[0054] In further embodiments, the DDS and/or DDS derivative or any
of the upstream product feedstreams disclosed herein optionally can
comprise a catalyst. Suitable catalysts include without limitation,
metallic catalysts and non-metallic catalysts. Metal catalysts
include, without limitation, metal oxides, including, for example,
zinc oxide, titanium dioxide, copper oxides, (cuprous oxide and/or
cupric oxide), aluminum oxide, calcium oxide, stannous oxide, lead
oxide and other metal oxides; and metals, for example, zinc,
titanium, copper, iron, nickel, zirconium, and aluminum. Other
catalysts include, without limitation, fly ash and Portland
cement.
[0055] Some oxides also assist with odor reduction and increase the
shelf life. Without being bound by theory, oxides, such as titanium
dioxide, may reduce auto-oxidation.
[0056] In some embodiments, the DDS and/or DDS derivative or any of
the upstream product feedstreams disclosed herein optionally can
comprise a vulcanizing agent. Suitable vulcanizing agents include
sulfur, zinc oxides, MDI urethanes, and the like.
[0057] In further embodiments, the DDS and/or DDS derivative or any
of the upstream product feedstreams disclosed herein optionally can
comprise a crosslinker Crosslinking agents also have the ability to
increase the mechanical and physical performance of the present
biopolymer. As used herein, crosslinking generally refers to
linking at least two polymer chains comprised, for example, of
proteins, peptides, polysaccharides, and/or synthetic polymers of
the corn protein material.
[0058] Suitable crosslinking agents include one or more of metallic
salts (e.g., NaCl or rock salt) and salt hydrates (which may
improve mechanical properties), urea, formaldehyde,
urea-formaldehyde, polyesters, phenol and phenolic resins,
melamine, methyl diisocyanide (MDI), polymeric methyl diphenyl
diisocyanate (pMDI), polymeric hexamethylene diisocyanate (pHMDI),
amine-epichlorohydrin adducts, epoxides, zinc sulfate, aldehydes
and urea-aldehyde resins epoxides, aldehyde, aldehyde starch,
dialdehyde starch, glyoxal, urea glyoxal, urea-aldehyde, polyamine
epichlorohydrin resin, polyamidoamine-epichlorohydrin resin,
polyalkylene polyamine-epichlorohydrin, amine
polymer-epichlorohydrin resin epoxy, resin mixtures, combinations
thereof, and the like. The same or similar agents may also serve as
binders.
[0059] The amine-epichlorohydrin adducts are defined as those
prepared through the reaction of epichlorohydrin with
amine-functional compounds. Among these are
polyamidoamine-epichlorohydrin resins (PAE resins),
polyalkylenepolyamine-epichlorohydrin (PAPAE resins) and amine
polymer-epichlorohydrin resins (APE resins). The PAE resins include
secondary amine-based azetidinium-functional PAE resins, tertiary
amine polyamide-based epoxide-functional resins and tertiary amine
polyamidourylene-based epoxide-functional PAE resins. It is also
possible to use low molecular weight amine-epichlorohydrin
condensates.
[0060] Additional additives can include a fiber additive. Suitable
fibers include any of a variety of natural and synthetic fibers.
Cellulose fibers include, without limitation, those from wood,
agricultural fibers, including flax, hemp, kenaf, wheat, soybean,
switchgrass, and grass, fibers obtained from paper and other fiber
recycling, including, without limitation, household and industrial
paper recycling streams, fibrous waste from the paper or wood
industries, including paper mill sludge. Synthetic fibers include
fiberglass, Kevlar, carbon fiber, nylon; mixtures or combinations
thereof, and the like. Mineral or silica additives may also be
used. The fiber can modify the performance of the biopolymers. For
example, longer fibers can be added to impart higher flexural and
rupture modulus to the cured or dried biopolymer.
[0061] Nanomaterials may also be used as fillers, including
NanoCell (LDI Composites), which is a blend of cellulose, minerals
and clay that has been processed into a submicron material. It is
derived from paper mill sludge. NanoCell also contains small
percentages of metals and titanium dioxide. Other forms of
nanomaterials, such as nanofibers, nanotubes, nanocellulosics,
nanoclays and other forms of nanomaterials may also be included in
the DDS biocomposite additive and/or the biopolymer.
[0062] Other materials that can include components found in latex
paint, including, without limitation, latex compounds, including,
without limitation, acrylic latexes such as styrenated acrylic
latex; calcium carbonate, colorants, dispersants, such as, for
example, napthalene sulfonic acid condensation products; ammonium
hydroxide; surfactants; glycol ethers, including (propylene glycol)
methyl ether; 2,2,4-trimethylpentanediol-1,3-monoisobutyrate;
sodium nitrite; ethylene glycols, such as triethylene glycol
bis(2-ethylhexanoate); drying agents, such as metal oxides,
including, without limitation, zirconium oxides, cobalt oxides and
iron oxides, as well as ethylene oxides and ethylene oxide
derivatives and condensates, including, without limitation, fatty
alcohol ethoxylate, alkylphenol ethoxylate, fatty acid ethoxylate,
ethoxylated fatty amines, and the like; preservatives, emulsifiers
and thickeners.
[0063] Additional additives include citric acid including citric
acid monohydrate contains many carboxyl groups that are expected to
interact with both proteins and cellulosic based materials at
elevated temperatures.
[0064] The DDS can also be dry blended with a wide range of
additional powder resin as a bioextender to either lower the cost
of the petrochemical resin powder or provide functional advantages
to the overall blend. DDS can also be added to various formaldehyde
resins wherein the proteins can scavenge the residual formaldehyde
and increase the biobased content of the resulting product. Such
powder or liquid resins include but not limited to: phenol
formaldehyde, urea formaldehyde and melamine formaldehyde
adhesives.
[0065] As noted above, the DDS after being subjected to the drying
process is in powder and/or granular form. The resulting DDS is
elastomeric and can be injection molded to extruded to form a
stable profiled article of manufacture. The particular end use for
the article of manufacture is not intended to be limited. For
example, flat sheets can be readily formed or profiled structures
can be formed. Advantageously, low temperature extrusion processes,
typically less than 200.degree. F., can be used to form various
products such as, for example, baseboards, edgebanding, and other
flexible profiles.
[0066] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to make and use the invention. The patentable
scope of the invention is defined by the claims, and may include
other examples that occur to those skilled in the art. Such other
examples are intended to be within the scope of the claims if they
have structural elements that do not differ from the literal
language of the claims, or if they include equivalent structural
elements with insubstantial differences from the literal languages
of the claims.
* * * * *