Process for protein enrichment of dried distillers grains using a tribo-electrostatic separator device
A tribo-electrostatic separation process for fractionating a feed mixture derived from dried distiller's grains (DDG) or distiller's dried grains and mixed with solubles (DDGS) is disclosed.
1. A process for fractionating a feed mixture derived from dried distiller's grains (DDG) or distiller's dried grains and mixed with solubles (DDGS) using a single-step tribo-electrostatic separation process, comprising:
a. drying the DDG or DDGS feed mixture
b. milling the DDG or DDGS feed mixture to a median particle size of 225-250 microns;
c. supplying said milled DDG or DDGS feed mixture to a tribo-electrostatic separator; and
d. simultaneously tribo-electrically charging and separating said DDG or DDGS feed mixture into at least two subfractions, with one of the subfractions having a protein composition higher than the DDG or DDGS feed mixture.
2. The process of claim 1 , wherein the pre-drying moisture level for the feed mixture was greater than 10.3% and the feed mixture moisture content after drying was less than 7.9%.
3. The process of claim 1 , wherein the DDG or DDGS feed mixture is characterized by a protein level of between 30-45%, an oil content of less than 20%, and/or a moisture content of less than 30%.
4. The process of claim 3 , wherein the feed protein level is in a range of from 30% to 35%.
5. The process of claim 4 , wherein the protein level of one of the sub-fractions is enriched to be anywhere in a range of from 35% to 55%.
6. The process of claim 3 , wherein the feed moisture content is from 0% to 12%.
7. The process of claim 3 , wherein the feed oil content is from 0.7% to 12.0%.
8. The process of claim 1 , wherein the protein level of one of the subfractions is enriched by an absolute protein increase of 5% to 25%.
9. The process of claim 1 , wherein the feed mixture is processed at a rate of 40 to 17,000 kg per hour per meter of TBS electrode width.
10. The process of claim 1 , wherein a belt speed of the tribo-electrostatic separation process is from 10 to 70 feet per second.
11. The process of claim 1 , wherein an electric field strength of the tribo-electrostatic separation process is from 120 to 4,000 kV/m.
12. The process of claim 1 , wherein an absolute protein increase of at least 10% is achieved.
13. The process of claim 12 , wherein the DDG or DDGS feed mixture is dried in order to achieve a moisture content of 6.4% or less.
14. A process for fractionating a feed mixture derived from dried distiller's grains (DDG) or distiller's dried grains and mixed with solubles (DDGS) using a single-step tribo-electrostatic separation process, comprising:
a. milling the DDG or DDGS feed mixture to a median particle size of less than 150 microns;
b. supplying said milled DDG or DDGS feed mixture to a tribo-electrostatic separator; and
c. simultaneously tribo-electrically charging and separating said DDG or DDGS feed mixture into at least two subfractions, with one of the subfractions having a protein composition higher than the DDG or DDGS feed mixture; and
wherein the milled DDG or DDGS feed mixture need not be dried.
15. The process of claim 14 , wherein the milled feed mixture moisture content is less than 7.9%.
16. The process of claim 14 , wherein an absolute protein increase of at least 10% is achieved.
17. The process of claim 14 , wherein the DDG or DDGS feed mixture is milled to a particle size of 50-75 microns.
18. The process of claim 14 , wherein the DDG or DDGS feed mixture is characterized by a protein level of between 30-45%, an oil content of less than 20%, and/or a moisture content of less than 30%.
19. The process of claim 14 , wherein the feed protein level is in a range of from 30% to 35%.
20. The process of claim 14 , wherein the protein level of one of the subfractions is enriched by an absolute protein increase of 5% to 25%.
21. The process of claim 14 , wherein the feed moisture content is from 0% to 12%.
22. The process of claim 14 , wherein the feed oil content is from 0.7% to 12.0%.
23. The process of claim 14 , wherein the feed mixture is processed at a rate of 40 to 17,000 kg per hour per meter of TBS electrode width.
24. The process of claim 14 , wherein a belt speed of the tribo-electrostatic separation process is from 10 to 70 feet per second.
25. The process of claim 14 , wherein an electric field strength of the tribo-electrostatic separation process is from 120 to 4,000 kV/m.