Recovery of co-products from fermentation stillage streams
Processes and methods of recovering desired products from fermentation stillage are presented, including processes and methods of recovering lipids and aqueous materials.
1. A method of recovering oil from stillage, comprising:
mechanically separating a mixture comprising a light phase oil material having an oil-in-water emulsion from the stillage, wherein the light phase oil material has a moisture content of greater than about 5% by weight;
adding at least one emulsion breaking additive to the light phase oil material to generate a chemically processed mixture, wherein the emulsion breaking additive is not a polar protic solvent and comprises at least one polymeric material; and
mechanically separating an oil product from the chemically processed mixture.
2. The method of claim 1 , wherein the emulsion breaking additive is present at a level of about 500 ppm to about 2000 ppm based on the weight of the light phase oil material.
3. The method of claim 1 , wherein the emulsion breaking additive does not substantially adjust the pH of the light phase oil material.
4. A method of recovering oil from stillage, comprising:
mechanically separating a mixture comprising a light phase oil material having an oil-in-water emulsion from the stillage, wherein the light phase oil material has a moisture content of greater than about 5% by weight;
adding at least one emulsion breaking additive to the light phase oil material to generate a chemically processed mixture, wherein the emulsion breaking additive increases the surface tension of the oil in the oil-in-water emulsion and is not a polar protic solvent; and
mechanically separating an oil product from the chemically processed mixture.
5. A method of recovering oil from stillage, comprising:
mechanically separating a mixture comprising a light phase oil material having an oil-in-water emulsion from the stillage, wherein the light phase oil material has a moisture content of greater than about 5% by weight;
adding at least one emulsion breaking additive to the light phase oil material to generate a chemically processed mixture, wherein the emulsion breaking additive is not a polar protic solvent and comprises at least one non-polymeric material; and
mechanically separating an oil product from the chemically processed mixture.
6. The method of claim 1 , wherein the emulsion breaking additive is a polysorbate.
7. The method of claim 1 , wherein the emulsion breaking additive is an anionic copolymer comprising acrylic acid sodium salt, methacrylic acid sodium salt or 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt.
8. The method of claim 1 , wherein the stillage is concentrated thin stillage.
9. The method of claim 1 , wherein mechanically separating the light phase oil material comprises centrifugation.
10. The method of claim 1 , wherein mechanically separating the oil product from the chemically processed mixture comprises centrifugation.
11. The method of claim 1 , wherein mechanically separating the mixture comprising the light phase oil material from the stillage further comprises mechanically separating an aqueous phase mixture and a solids phase mixture from the stillage.
12. The method of claim 1 , wherein the stillage is at a temperature of about 140° F. to about 212° F. when mechanically separated.
13. The method of claim 1 , wherein the light phase oil material is at a temperature of about 100° F. to about 212° F. when the at least one emulsion breaking additive is added.
14. The method of claim 1 , wherein the light phase oil material has a specific gravity of about 0.90 to about 0.98 at a temperature of about 25° C.
15. A system for recovering oil from stillage, comprising:
a first mechanical separator for separating a mixture comprising a light phase oil material having an oil-in-water emulsion from the stillage, wherein the light phase oil material has a moisture content of greater than about 5% by weight;
a dispenser for adding at least one emulsion breaking additive to the light phase oil material stream to generate a chemically processed mixture, wherein the emulsion breaking additive is not a polar protic solvent and comprises at least one polymeric material; and
a second mechanical separator for separating an oil product from the chemically processed mixture.
16. The system of claim 15 , wherein at least one of the first mechanical separator and the second mechanical separator is a centrifuge, wherein the dispenser is an injector, and wherein the emulsion breaking additive is an anionic copolymer comprising acrylic acid sodium salt, methacrylic acid sodium salt, or 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt.
17. A method for recovering oil from stillage, comprising:
mechanically separating a stillage to provide a light phase oil material having an oil-in-water emulsion, wherein the light phase oil material has a moisture content of about 5% by weight to about 50% by weight;
adding at least one emulsion breaking additive to the light phase oil material to produce a chemically processed mixture, wherein the emulsion breaking additive comprises an anionic copolymer comprising an acrylic acid sodium salt, a methacrylic acid sodium salt, or 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt; and
mechanically separating the chemically processed mixture to provide an oil product comprising greater than 95% by weight of oil.
18. The method of claim 17 , wherein:
the stillage is at a temperature of about 140° F. to about 212° F. when mechanically separated,
the light phase oil material has a specific gravity of about 0.90 to about 0.98 at a temperature of about 25° C.,
the light phase oil material is at a temperature of about 100° F. to about 212° F. when the at least one emulsion breaking additive is added,
the chemically processed mixture comprises about 500 ppm to about 2000 ppm of the emulsion breaking additive based on a weight of the light phase oil material, and
the oil product comprises less than 2% by weight of water.
19. The method of claim 18 , wherein:
the light phase oil material has a specific gravity of about 0.92 to about 0.98 at a temperature of about 25° C.,
mechanically separating the stillage further provides an aqueous phase mixture and a solids phase mixture,
the stillage comprises less than 10% by weight of the aqueous phase mixture and at least 10% by weight of the light phase oil material, and
the emulsion breaking additive does not contain a polar protic solvent.
20. The method of claim 5 , wherein the emulsion breaking additive is a diepoxide.