U.S. patent number RE47,268 [Application Number 15/273,133] was granted by the patent office on 2019-03-05 for separation of biocomponents from ddgs.
The grantee listed for this patent is Aicardo Roa-Espinosa. Invention is credited to Aicardo Roa-Espinosa.
United States Patent |
RE47,268 |
Roa-Espinosa |
March 5, 2019 |
Separation of biocomponents from DDGS
Abstract
A multi stage process for the separation of bio-components from
a waste stream containing Dried Distillers Grains with Solubles is
disclosed. Targeted polymers are added to the source and separated
streams prior to passing the streams through separation equipment
including a rotary screen, a press, and a dissolved air floatation
in which the waste stream is separated into a stream containing
predominantly protein, a stream containing predominantly oil, a
stream containing predominantly water and a stream that contains
predominantly fibers.
Inventors: |
Roa-Espinosa; Aicardo (Madison,
WI) |
Applicant: |
Name |
City |
State |
Country |
Type |
Roa-Espinosa; Aicardo |
Madison |
WI |
US |
|
|
Family
ID: |
65496025 |
Appl.
No.: |
15/273,133 |
Filed: |
November 16, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
14190332 |
Feb 26, 2014 |
|
|
|
Reissue of: |
14518310 |
Oct 20, 2014 |
9051538 |
Jun 9, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C12F
3/10 (20130101); C02F 1/5272 (20130101); B03D
1/10 (20130101); B03D 1/01 (20130101); B03D
1/02 (20130101); C12F 3/10 (20130101); C08B
1/00 (20130101); C12F 3/00 (20130101); C08H
8/00 (20130101); C08L 91/00 (20130101); C08L
89/00 (20130101); C11B 13/00 (20130101); B30B
13/00 (20130101); A23K 10/38 (20160501); A23J
1/005 (20130101); C02F 3/10 (20130101); C02F
9/00 (20130101); C02F 1/24 (20130101); C08L
89/00 (20130101); C08L 91/00 (20130101); C08L
91/00 (20130101); C08L 89/00 (20130101); Y02W
30/74 (20150501); Y02W 30/74 (20150501); C07K
1/30 (20130101); Y02P 60/87 (20151101); C08L
89/00 (20130101); C02F 2103/32 (20130101) |
Current International
Class: |
A23J
1/00 (20060101); C11B 13/00 (20060101); A23K
10/38 (20160101); C08L 89/00 (20060101); B30B
13/00 (20060101); C12F 3/10 (20060101); C08B
1/00 (20060101); C07K 1/30 (20060101); C02F
9/00 (20060101); C02F 3/10 (20060101); C02F
1/52 (20060101); C02F 1/24 (20060101); B03D
1/10 (20060101); B03D 1/02 (20060101); B03D
1/01 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McKane; Elizabeth L
Attorney, Agent or Firm: Greenfield; Steven H Greenfield
Invention and Patent Consulting, Inc.
Parent Case Text
RELATED APPLICATIONS
This application is a continuation in part application claiming
priority from non-provisional application Ser. No. 14/190,332 filed
on Feb. 26, 2014.
Claims
I claim:
1. A multi-stage substantially continuous process for separating a
source stream .Iadd.comprising dried distillers grain with
solubles, .Iaddend.said source stream intermixedly containing
fibers, water, protein and oil, said process being configured for
separating the source stream into streams each containing
predominantly one component, .[.said source stream containing dried
distillers grains with solubles,.]. said process comprising the
stages of: .Iadd.(a) .Iaddend.providing a source stream comprising
.[.dried distillers grain with solubles, said dried distillers
grain stream containing.]. water, oil, protein and fibers;
.Iadd.(b) .Iaddend.separating said source stream into .[.a second
stream and a third stream, said second stream having.]. a
.Iadd.first .Iaddend.non-aqueous portion containing predominantly
fibers, .[.said third stream having.]. .Iadd.and .Iaddend.a
.Iadd.second .Iaddend.non-aqueous portion containing predominantly
a mixture of oil and protein.[., separating a fourth stream and a
fifth stream from said third stream, said fourth stream containing
about 99 percent water and said fifth stream containing between
about 15 percent to about 25 percent oil and protein,.]..Iadd.; (c)
.Iaddend..[.wherein separating the fourth stream and the fifth
stream from said third stream is accomplished by.]. passing said
.[.third stream.]. .Iadd.second non-aqueous portion
.Iaddend.through a .[.second.]. chemical additive pipe having a
.[.second.]. chemical addition inlet .[.and a third chemical
addition inlet,.]. said .[.second.]. chemical additive pipe leading
toward a .[.D.]..Iadd.d.Iaddend.issolved .[.A.]..Iadd.a.Iaddend.ir
.[.F.]..Iadd.f.Iaddend.loatation device.[., said third chemical
addition configured to occur about 15 seconds after the second
chemical addition based on an average volumetric flow rate through
the pipe; adding between about 5 to about 25 ppm of a cationic
acrylamide copolymer to the second chemical addition inlet; and
feeding said third stream into the a Dissolved Air Floatation
device wherein actions of said Dissolved Air Floatation device
separate said third stream into the fourth stream and the fifth
stream; and.]..Iadd.; (d) adding about 5 to about 25 ppm of a
cationic acrylamide copolymer to the second non-aqueous portion at
the chemical addition inlet of the chemical additive pipe, so as to
form a mixture of the cationic acrylamide copolymer and the second
non-aqueous portion, the chemical additive pipe having a second
chemical addition inlet and a third chemical addition inlet wherein
a third chemical addition is configured to occur about 15 seconds
after a second chemical addition based on an average volumetric
flow rate through the pipe; (e) separating said mixture of (d) into
a predominantly water fraction and a non-aqueous fraction including
oil, protein and water in the dissolved air flotation device, said
predominantly water fraction containing about 99 percent water,
said non-aqueous fraction containing between about 15 percent and
about 25 percent oil and protein; and (f) .Iaddend.separating from
the .[.fifth stream a stream containing.]. .Iadd.non-aqueous
fraction of step (e) a .Iaddend.predominantly oil .Iadd.fraction
.Iaddend.and a .[.stream comprising.]. predominantly protein
.[.through the steps of drying, size reduction, and pressing out
the oil.]. .Iadd.fraction, wherein separating the source stream
into the first non-aqueous portion and the second non-aqueous
portion comprises: adding 5 to about 25 ppm of cationic polyamine
to the source stream: separating the first non-aqueous portion and
the second non-aqueous portion from said source stream with a
rotary screen and wherein step (e) is accomplished by the steps of:
removing water from the non-aqueous fraction to achieve about 90
percent to about 95% solids content in the non-aqueous fraction,
said water removal being accomplished by a pressing step, a
vacuuming step and a drying step, said water removal step
generating a dried cake containing predominantly oil and protein
having particles; reducing a particle size of the dried cake by
passing the dried cake through a hammermill to generate a
fragmented dried cake said fragmented dried cake containing
predominantly oil and protein particles; and passing the fragmented
dried cake through a heated oil press to generate a dried fraction
containing predominantly oil and a dried fraction containing
predominantly protein.Iaddend..
.[.2. The process of claim 1, wherein separating the source stream
into the second stream and the third stream is accomplished by:
passing said source stream through a first chemical additive pipe
having a first chemical addition inlet, said first chemical
additive pipe leading toward a rotary screen; adding between about
5 to about 25 ppm of cationic polyamine to the first stream at said
first chemical addition inlet; and separating the second stream and
the third stream from said source stream in the rotary
screen..].
.[.3. The process of claim 1 wherein separating the fifth stream a
stream containing predominantly oil and a stream comprising
predominantly protein is accomplished by the steps of: removing
water from the fifth stream to achieve between about 90 percent and
about 95% solids, said water removal being accomplished by a
pressing step, a vacuuming step and a drying step, said water
removal step generating an eighth stream, said eighth stream
constituting of a dried cake containing predominantly oil and
protein having a particles ranging in size between about 0.2 inches
to about 0.5 inches; reducing the particle size of the eighth
stream by passing said eighth stream through a hammermill to
generate a ninth stream, said ninth stream constituting of a dried
cake containing predominantly oil and protein having particles
ranging in size from between about 0.05 inches to about 0.2 inches;
and separating the ninth stream into a tenth stream containing
predominantly oil and an eleventh stream containing predominantly
protein, said separating being accomplished by passing the ninth
stream through a heated oil press..].
4. The process of claim .[.3.]. .Iadd.1 .Iaddend.further comprising
passing the .[.tenth stream.]. .Iadd.dried fraction containing
predominantly oil .Iaddend.through a filter, while adding
.[.between.]. about 5 to about 25 ppm of cationic polyamine to said
filter .[.based on the average volumetric flow rate through the
pipe.]., said polyamine addition resulting in precipitating any
protein residual from said .[.tenth stream.]. .Iadd.dried fraction
containing predominantly oil.Iaddend..
5. The process of claim .[.3 further comprising.]. .Iadd.1 wherein
the .Iaddend.pressing .[.the fifth stream, said pressing being.].
.Iadd.step is .Iaddend.accomplished in either a multidisc press or
a screw press, .[.wherein.]. .Iadd.said .Iaddend.pressing
.[.separates.]. .Iadd.step separating .Iaddend.the .[.fifth
stream.]. .Iadd.non-aqueous fraction .Iaddend.into a .[.seventh
stream.]. .Iadd.first non-aqueous component .Iaddend.having a water
content .[.between.]. .Iadd.of .Iaddend.about 30 percent .[.and.].
.Iadd.to .Iaddend.about 40 percent and a .[.twelfth stream
containing.]. .Iadd.second non-aqueous component having .Iaddend.a
water content of above 40 percent, .[.said twelfth stream being
passed.]. .Iadd.and wherein the vacuuming step is accomplished by
passing said second non-aqueous component .Iaddend.through a vacuum
drum, said vacuum drum removing a water residue stream.[., said
water residue stream being combined with the fourth stream.]..
6. The process of claim 5, further comprising adding to the vacuum
drum .[.between.]. about 5 to about 25 ppm of anionic acrylamide
copolymer having a .[.MW.]. .Iadd.molecular weight .Iaddend.of
.[.between.]. about 18 million to about 24 million.
7. The process of claim .[.3.]. .Iadd.1 .Iaddend.wherein .Iadd.the
.Iaddend.drying .[.constitutes.]. .Iadd.step comprises
.Iaddend.passing the .[.seventh stream.]. .Iadd.first non-aqueous
component .Iaddend.through a dryer wherein water vapor in a
temperature range of .[.between.]. about 60.degree. C. and about
88.degree. C. is injected prior to drying.
8. The process of claim 1, further comprising passing said
.[.second stream.]. .Iadd.first non-aqueous portion containing
predominantly fibers .Iaddend.through a press to generate .[.a
sixth stream.]. .Iadd.an aqueous fraction.Iaddend., said .[.sixth
stream.]. .Iadd.aqueous fraction .Iaddend.containing predominantly
water, and combining the .[.sixth stream.]. .Iadd.aqueous fraction
.Iaddend.with the .[.third stream.]. .Iadd.second non-aqueous
portion .Iaddend.prior to .[.entering the Dissolved Air Floatation
device.]. .Iadd.step (e).Iaddend..
9. The process of claim 1 further comprising treating the .[.fourth
stream.]. .Iadd.predominantly water fraction .Iaddend.with
.[.between.]. about 5 to about 25 ppm of anionic acrylamide
copolymer .[.to reduce.]. .Iadd.thereby reducing .Iaddend.COD and
BOD levels of said .[.fourth stream.]. .Iadd.predominantly water
fraction.Iaddend..
10. The process of claim 1 further comprising .Iadd.measuring the
pH of said second non-aqueous portion and .Iaddend.adding
.[.between.]. about 5 to about 25 ppm of .[.an.]. anionic
acrylamide copolymer to said .[.third chemical addition inlet if.].
.Iadd.second non-aqueous portion when .Iaddend.the pH of the
.[.third stream.]. .Iadd.second non-aqueous portion .Iaddend.is
greater than 5.5.
11. The process of claim 1, wherein a charge of the cationic
acrylamide copolymer is in a range of .[.between.]. about 20
percent .[.and.]. .Iadd.to about .Iaddend.40 percent.
.Iadd.12. The process of claim 5, further comprising combining the
water residue fraction with the predominantly water
fraction..Iaddend.
.Iadd.13. The process of claim 1, wherein the predominantly water
fraction contains at least 97% water by weight..Iaddend.
.Iadd.14. A process of separating components of waste material from
ethanol production, the process comprising: providing a source
stream of waste material from ethanol production, the source stream
comprising dried distillers grain with solubles and including
water, fiber, protein, and oil components; and separating the
water, fiber, protein, and, oil components from the source stream
into a predominantly water fraction, a predominantly fiber
fraction, a predominantly protein fraction, and a predominantly oil
fraction by: (a) removing fiber components from the source stream
to produce the predominantly fiber fraction and a low solids stream
including water, protein, and oil; (b) treating the low solids
stream with a cationic acrylamide polymer to form a treated low
solids stream, said treating the low solids stream with a cationic
acrylamide polymer being accomplished through chemical addition to
a pipe containing a second chemical addition inlet and a third
chemical addition inlet wherein a third chemical addition is
configured to occur about 15 seconds after a second chemical
addition based on an average volumetric flow rate through the pipe;
(c) passing the treated low solids stream in (b) through a
dissolved air flotation device that separates the treated low
solids stream into the predominantly water fraction and a
non-aqueous fraction including oil, protein and water, the
predominantly water fraction containing about 99 percent water, the
non-aqueous fraction containing about 15 percent to about 25
percent oil and protein; (d) removing water from the non-aqueous
fraction in (c) to form a predominantly protein and oil mixture
fraction; and (e) separating the predominantly protein and oil
mixture fraction into the predominantly protein fraction and the
predominantly oil fractions; wherein removing fiber components from
the source stream to produce the predominantly fiber fraction
comprises: adding about 5 to about 25 ppm of cationic polyamine to
the source stream; separating the predominantly fiber fraction and
the low solids stream from said source stream with a rotary screen;
wherein separating the predominantly protein and oil mixture
fraction into the predominantly protein fraction and the
predominantly oil fraction comprises: removing water from the
non-aqueous fraction to achieve about 90 percent to about 95
percent solids content in the non-aqueous fraction, said water
removal being accomplished by a pressing step, a vacuuming step and
a drying step, said water removal step generating a dried cake
containing predominantly oil and protein particles; reducing a
particle size of the dried cake by passing the dried cake through a
hammermill to generate a fragmented dried cake, said fragmented
dried cake containing predominantly oil and protein particles; and
passing the fragmented dried cake through a heated oil press to
generate a dried fraction containing predominantly oil and a dried
fraction containing predominantly protein..Iaddend.
.Iadd.15. The process of claim 14, further comprising passing the
dried fraction containing predominantly oil through a filter, while
adding about 5 to about 25 ppm of cationic polyamine to said
filter, said polyamine addition resulting in precipitating any
protein residual from said dried fraction containing predominantly
oil..Iaddend.
.Iadd.16. The process of claim 14, wherein the pressing step is
accomplished in either a multidisc press or a screw press, said
pressing step separating the non-aqueous fraction into a first
non-aqueous component having a water content of about 30 percent to
about 40 percent and a second non-aqueous component having a water
content of above 40 percent, and wherein the vacuuming step is
accomplished by passing said second non-aqueous component through a
vacuum drum, said vacuum drum removing a water residue
fraction..Iaddend.
.Iadd.17. The process of claim 16, further comprising adding to the
vacuum drum about 5 to about 25 ppm of anionic acrylamide
copolymer..Iaddend.
.Iadd.18. The process of claim 16, further comprising combining the
water residue fraction with the predominantly water
fraction..Iaddend.
.Iadd.19. The process of claim 14, wherein the drying step
comprises passing the first non-aqueous component through a dryer
wherein water vapor in a temperature range of about 60.degree. C.
to about 88.degree. C. is injected prior to drying..Iaddend.
.Iadd.20. The process of claim 14, further comprising: passing said
predominantly fiber fraction through a press to generate an aqueous
fraction, said aqueous fraction containing predominantly water; and
combining the aqueous fraction with the low solids stream prior to
step (c)..Iaddend.
.Iadd.21. The process of claim 14, further comprising treating the
predominantly water fraction with about 5 to about 25 ppm of
anionic acrylamide copolymer, thereby reducing COD and BOD levels
of said predominantly water fraction..Iaddend.
.Iadd.22. The process of claim 14, further comprising measuring a
pH of the low solids stream and adding an anionic acrylamide
copolymer to said low solids stream when the pH of the low solids
stream is greater than 5.5..Iaddend.
.Iadd.23. The process of claim 14, wherein a charge of the cationic
acrylamide copolymer is in a range of between about 20 percent and
40 percent..Iaddend.
.Iadd.24. The process of claim 14, wherein the predominantly water
fraction contains at least 97% water by weight..Iaddend.
Description
FIELD OF THE INVENTION
The present invention relates generally to a process of recovering
useful materials from waste sources that include Dried Distillers
Grains with Solubles also known by the acronym DDGS, waste
materials from ethanol production and animal feed waste.
BACKGROUND OF THE INVENTION
Thin stillage and distillers' grains are byproducts remaining after
alcohol distillation from a fermented cereal grain mash. Both
byproducts are used as energy and protein sources for ruminants.
There are two main sources of these byproducts. The traditional
sources were from brewers. However, more recently, ethanol plants
such as corn, sugar cane, cassaya and potatoes have become a
growing source.
DDGS contain valuable bio-materials mainly fibers, oil and protein.
The oil in DDGS could be used either as cooking oil or as a
biofuel. The main protein in corn is Zein which has been used in
the manufacture of a wide variety of commercial products, including
coatings for paper cups, soda bottle cap linings, clothing fabric,
buttons, adhesives, coatings and binders, recently this protein has
been used as a coating for candy, nuts, fruit, pills, and other
encapsulated foods and drugs. Additionally Zein can be further
processed into resins and other bioplastic polymers. Fibers may be
used as raw materials in the production of lignocellulosic ethanol.
Residue materials from ethanol production contain fibers from which
ethanol has been extracted. However, only about 50-70% of the
ethanol in these materials is typically extracted leaving
substantial portion of ethanol that is available for further
extraction. Tables 1 and 2 provide a typical content breakdown of
the various materials in DDGS.
TABLE-US-00001 TABLE 1 Cellulosic biomass compositional analysis of
DDGS. Average Dry matter 88.8 Water extractives 24.7 Ether
extractives 11.6 Crude protein 24.9 Glucan (total) 21.2 Cellulose
16 Starch 5.2 Xylan and Arabinan 13.5 Xylan 8.2 Arab Man 5.3 Ash
4.5 Total dry matter 100.4
TABLE-US-00002 TABLE 2 Nutritional Compositional analysis of DDGS.
Nutritional Compositional analysis Dry matter 88.9 Crude at 14.5
Carbohydrates 53.5 Ash 4.7 Total 100
It would therefore be desirable to provide a process to separate
these materials in order to maximize their uses.
SUMMARY OF THE PRESENT INVENTION
In an aspect of the present invention, a multi-stage substantially
continuous process for separating a source stream said source
stream intermixedly containing fibers, water, protein and oil, said
process being configured for separating the source stream into
streams each containing predominantly one component, said source
stream containing dried distillers grains with solubles, said
process comprises the stages of: providing a source stream
comprising dried distillers grain with solubles, said dried
distillers grain stream containing water, oil, protein and fibers;
separating said source stream into a second stream and a third
stream, said second stream containing predominantly fibers, said
third stream containing predominantly a mixture of oil, protein and
water, said separating being accomplished through the treatment of
the first stream with; separating a fourth stream and a fifth
stream from said third stream, said fourth stream containing
predominantly water and said fifth stream containing predominantly
oil and protein; and separating from the fifth stream a stream
containing predominantly oil and a stream comprising predominantly
protein through the steps of drying, size reduction, and pressing
out the oil.
These and other features, aspects and advantages of the present
invention will become better understood with reference to the
following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart schematic of the process according to an
embodiment of the present invention; and
FIG. 2 is a flow chart schematic of the process according to
another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The following detailed description is of the best currently
contemplated modes of carrying out exemplary embodiments of the
invention. The description is not to be taken in a limiting sense,
but is made merely for the purpose of illustrating the general
principles of the invention.
The main components of Raw Dried Distillers Grains with Solubles
(DDGS) include water in the range of between about 70% to about
95%, but could also be higher or lower depending on the source.
It is desirable that the water content of the source DDGS stream be
consistent in order for the process to be stable. Therefore, water
is added as needed to ensure that the solids level in the DDGS
entering the process does not exceed 30%.
The process consists of mechanical separation steps aided by
polymeric additions to separate the DDGS into four streams each
containing predominantly one component: fibers, water, oil and
protein.
In the first step, the DDGS source stream is introduced into a
rotary screen through a 1'' pipe. Between 5-25 ppm of a cationic
polyamine having a 50% charge and a MW of about 800,000 are added
to the pipe. This helps precipitate a stream that contains water
and non-aqueous matter, predominantly fibers ranging in length from
some 0.01'' to as long as 0.5 inches, and having a non-aqueous
content of between about 25% and about 35%. This stream, labeled as
the 2.sup.nd stream in FIGS. 1 and 2 is passed through a press that
squeezes fluid from this stream and concentrates it to between
about 40% to about 50% solids. The fluid removed from the 2.sup.nd
stream by the press contains water and some protein and oil. It is
labeled as the 6.sup.th stream, and is further processed to
separate any oil and protein from it. The press may be a multidisc
press or a screw press; however other press types also fall within
the scope of this invention.
It is noted that the term "contains predominantly" refers to a
content of more than 50% in the context of the present
invention.
The low solids stream exiting the rotary screen contains
predominantly water at between 95 percent and 99 percent, and oil
and protein at between 1 to about 5 percent. It is labeled as the
third stream in FIGS. 1 and 2. The third stream is sent to a
Dissolved Air Floatation device (DAF) where it is separated into a
fourth stream containing predominantly water at >99% and a fifth
stream containing between about 75% to about 85% water and
non-aqueous matter containing mostly protein and oil. Helping with
the separation is polymer addition going into the pipe leading to
the Dissolved Air Floatation device using the 2.sup.nd and/or
3.sup.rd inlets. If the pH of the third stream is lower than 5.5,
between about 5 to about 25 ppm of a cationic acrylamide copolymer
are added to the 2.sup.nd inlet as shown in FIG. 1 which represents
the schematic of the process for a DDGS stream having a pH<5.5.
If the pH of the third stream is greater than 5.5, between about 5
to about 25 ppm of anionic acrylamide copolymer having a MW of
between about 18 million to about 24 million is also added to the
3.sup.rd inlet as shown in FIG. 2 which represent the schematic of
the process for a DDGS stream having a pH>5.5.
The cationic acrylamide copolymer has a Molecular Weight of between
about 8 million and about 19 million and between about 20 percent
to about 40 percent charge.
The sixth stream may be combined with the fourth stream prior to
entering the Dissolved Air Floatation device or combined with the
effluent water in the fourth stream, depending on the oil and
protein content of the sixth stream.
The 3.sup.rd inlet is set about 15 seconds below the second inlet
calculated based on the average volumetric flow rate through the
pipe.
Next, the fifth stream is passed through either a multidisc press
or a screw press that separates out of the fifth stream a low
moisture (<30%) stream labeled as the seventh stream and a high
moisture stream (>40%) labeled as the 12.sup.th stream in FIGS.
1 and 2. The 12.sup.th stream is passed through a vacuum drum to
reduce the moisture content of the 12.sup.th stream to between
about 20 percent and about 30 percent. To aid in the water removal,
about 5 to about 25 ppm of anionic acrylamide copolymer having a MW
of between about 18 to about 24 million are added to the vacuum
drum. The water removed from the vacuum drum is combined with the
fourth stream and the combined water stream is treated with between
about 5 to about 25 ppm of anionic acrylamide copolymer having a MW
of between about 18 million to about 24 million in order to reduce
the COD and BOD of the stream to dischargeable levels. The lower
moisture stream exiting the vacuum drum is labeled as the 13.sup.th
stream.
The seventh stream is passed through a dryer where most of the
moisture is removed leaving a cake of protein and oil having
relatively large material chunks generally from about 0.1 inches to
about 0.3 inches. This cake is labeled as the eighth stream. Also
entering the dryer is the 13.sup.th stream where it combines with
the seventh stream.
The eighth stream is passed through a hammermill that reduces the
particle sizes to generally less than 0.1'' thereby generating a
ninth stream. The ninth stream exiting the hammermill is pressed to
separate out a stream that is predominantly oil (10.sup.th stream)
from the cake and leaving the cake with a predominantly protein
content (11.sup.th stream). The predominantly oil stream is about
97% pure. The press may be a heated oil press or another type of
press suitable for this step. Water vapor in a temperature range of
between 60.degree. C. and about 88.degree. C. may optionally be
injected prior to the dryer to preheat the seventh stream and
increasing moisture uniformity in the stream. The tenth stream may
further be filtered and any residual protein precipitated out with
the aid of between about 5 ppm to about 25 ppm of a cationic
polyamine having a 50% charge and a MW of about 800,000 to bring
the purity of the tenth stream to around 99%.
The following represents the important characteristics of the
polymers used in the process.
Polyamines
Molecular weight between 10,000 and 1,000,000. Liquid form with 40
to 50% concentration. Cationic site on the main chain. Viscosity at
50% concentration of between 40 and 20,000 centipoises. Any
polyamine having two H.sub.2N groups may be used in this
application. An example may be 1,3-diaminopropane. Cationic
Acrylamide Copolymers
##STR00001## Sodium or Potassium Anionic Acrylate Acrylamide
Copolymer.
This polymer may be made from the reaction between an acrylamide
monomer and an acrylic acid monomer as shown below.
##STR00002##
The anionicity of these copolymers can vary between 0% and 100%
depending on the ratio of the monomers involved. The anionic
copolymers used in the process of the present invention may have a
molecular weight ranging between about 3 million to about 30
million, and a viscosity at a concentration of 5 g/l ranging from
about 200 centipoises to about 2800 centipoises. The preferred pH
range for making these copolymers is from 4.5 to 9. It is also
noted that potassium may be substituted for the sodium as the base
in the Acrylate Acrylamide copolymer.
It should be understood, of course, that the foregoing relates to
exemplary embodiments of the invention and that modifications may
be made without departing from the spirit and scope of the
invention.
* * * * *