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