Method for conditioning and processing whole or thin stillage to aid in the separation and recovery of protein and oil fractions

Patent metadata

Field	Value
Publication number	US-9776105-B2
Application number	US-94985010-A
Country	US
Kind code	B2
Filing date	Nov 19, 2010
Priority date	Nov 19, 2010
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

A method of processing thin stillage in an ethanol refining operation is provided. The method comprises treating thin stillage upstream of a concentration or evaporation step with an inverse emulsion comprising at least one anionic flocculant and an emulsifying agent selected from a sorbitan ester of a fatty acid, an ethoxylated sorbitan ester of a fatty acid, and combinations thereof, thereby forming treated thin stillage; clarifying the treated thin stillage via at least one of dissolved air flotation and induced air flotation, thereby forming clarified thin stillage and a float layer comprising oil and solids; separating the oil from the solids of the float layer; and recovering the oil.

First claim

The invention claimed is:

1. A method of processing thin stillage in an ethanol refining operation comprising:
treating thin stillage upstream of a concentration or evaporation step with an inverse emulsion comprising at least one anionic flocculant and an emulsifying agent selected from a sorbitan ester of a fatty acid, an ethoxylated sorbitan ester of a fatty acid, and combinations thereof, thereby forming treated thin stillage;
clarifying the treated thin stillage via at least one of dissolved air flotation and induced air flotation, thereby forming clarified thin stillage and a float layer comprising oil and solids;
separating the oil from the solids of the float layer; and
recovering the oil.

2. The method of claim 1 , wherein the emulsifying agent is polyoxyethylene sorbitan monostearate.

3. The method of claim 1 , wherein the thin stillage is treated with an amount of the inverse emulsion sufficient to provide a concentration of from about 50 ppm to about 500 ppm of total anionic flocculant in the thin stillage.

4. The method of claim 1 , wherein the separating the oil from the solids of the float layer is performed via heating and mechanical processing.

5. The method of claim 4 , wherein the mechanical processing is performed via at least one of a decanter, a tricanter, and a stacked disk centrifuge.

6. The method of claim 5 , wherein the mechanical processing is performed via a stacked disk centrifuge.

7. The method of claim 6 , wherein the beating and mechanical processing is performed at a temperature of from about 50° F. to 220° F.

8. The method of claim 7 , wherein the heating and mechanical processing is performed at a temperature of from about 150° F. to 212° F.

9. The method of claim 1 , wherein the emulsifying agent is sorbitan monooleate.

10. The method of claim 1 , wherein the emulsifying agent is polyoxyethylene sorbitan monolaurate.

11. The method of claim 1 , further comprising aging the treated thin stillage from 0.5 hours to 10 hours prior to the clarifying.

12. A method of processing thin stillage in an ethanol refining operation comprising:
inverting an inverse emulsion comprising at least one anionic flocculant and an emulsifying agent selected from a sorbitan ester of a fatty acid, an ethoxylated sorbitan ester of a fatty acid, and combinations thereof, by combining the inverse emulsion with water and an inverting surfactant, thereby forming a latex;
treating thin stillage upstream of a concentration or evaporation step with the latex, thereby forming treated thin stillage;
clarifying the treated thin stillage via at least, one of dissolved air flotation and induced air flotation, thereby forming clarified thin stillage and a float layer comprising oil and solids;
separating the oil from the solids of the float layer; and
recovering the oil.

13. The method of claim 12 , wherein the emulsifying agent is polyoxyethylene sorbitan monostearate.

14. The method of claim 13 , wherein the clarified thin stillage has a pH of from about 3 to about 6.

15. The method of claim 14 , wherein the thin stillage is treated with an amount of inverse emulsion sufficient to provide a concentration of from about 50 ppm to about 500 ppm of total anionic flocculant in the thin stillage.

16. The method of claim 12 , wherein the separating the oil from the solids of the float layer is performed via heating and mechanical processing.

17. The method of claim 16 , wherein the mechanical processing is performed via at least one of a decanter, a tricanter, and a stacked disk centrifuge.

18. The method of claim 17 , wherein the mechanical processing is performed via a stacked disk centrifuge.

19. The method of claim 18 , wherein the heating and mechanical processing is performed at a temperature of from about 150° F. to 220° F.

20. The method of claim 19 , wherein the heating and mechanical processing is performed at a temperature of from about 150° F. to 212° F.

21. The method of claim 12 , wherein the emulsifying agent is sorbitan monooleate.

22. The method of claim 12 , wherein the emulsifying agent is polyoxyethylene sorbitan monolaurate.

23. The method of claim 12 , further comprising aging the treated thin stillage from 0.5 hours to 10 hours prior to the clarifying.

Assignees

• Collins John H
• Scheimann David W
• Van'T Hul Jason S
• Eastin Philip M
• Nalco Co

Inventors

• Collins John H
• Scheimann David W
• Van'T Hul Jason S
• Eastin Philip M

Classifications

• Y02E50/10

  Biofuels, e.g. bio-diesel · CPC title

• C02F1/40

  Devices for separating or removing fatty or oily substances or similar floating material (cleaning or keeping clear the surface of open water from oil or like materials E02B15/04; devices in sewers for separating liquid or solid substances from sewage E03F5/14, e.g. for use in drains leading to the sewer E03F5/16) · CPC title

• C02F9/00

  Multistage treatment of water, waste water or sewage · CPC title

• B01D17/042

  by changing the temperature · CPC title

• C02F2303/10

  Energy recovery · CPC title