Systems and methods for stillage fractionation
View Patent ↗Systems and methods for fractionating whole stillage from an ethanol production facility are provided. Whole stillage undergoes a separation of its liquid portion (thin stillage) from the solid portion (fiber cake). In some embodiments, the solids and liquids in whole stillage may be separated utilizing a screening centrifuge. The fiber cake may be dried to generate a high fiber animal feed. The thin stillage may be provided to a three-phase separator for separation into an oil emulsion, an aqueous clarified stillage, and a protein paste. The protein paste may be dried to generate a high protein animal feed with greater than about 45% protein content. The clarified thin stillage is condensed to yield a syrup with greater than around 60% solids. The oil emulsion is subjected to a pH adjustment to liberate the oil from the emulsion, which is then separated.
1. A process for fractionating whole stillage comprising:
a first separator separating whole stillage to a solid portion and a thin stillage liquid portion, wherein the solid portion comprises a fiber cake;
a three phase separator receiving the thin stillage liquid portion and separating the thin stillage liquid portion to a clarified stillage, an oil emulsion and, a protein paste;
a first dryer drying the fiber cake to generate a fiber animal feed product;
a second dryer drying the protein paste to generate a protein animal feed product;
an evaporator condensing the clarified stillage to a syrup;
a second separator separating oil from the oil emulsion; and
a pH adjuster adjusting pH of the oil emulsion prior to separation by the second separator.
2. The process of claim 1 , wherein the pH adjuster adjusts the pH of the oil emulsion to about 8.0 to about 8.5.
3. The system of claim 1 , wherein the second separator separates at least 1.33 pounds of oil from the whole stillage generated from processing a bushel of corn for ethanol.
4. The system of claim 1 , wherein the evaporator condenses the clarified stillage to at least 60% solids.
5. The system of claim 1 , wherein the second dryer dries the protein paste to generate a protein animal feed product with at least 45% protein.
6. The system of claim 1 , wherein the second separator separates oil with at least 97% fat.
7. The system of claim 6 , wherein the second separator separates oil with less than 1% w/w moisture content and less than 1% w/w insolubles.
8. The process of claim 6 , wherein the second separator separates oil with less than 5% w/w free fatty acid content.
9. A method for fractionating stillage comprising:
separating whole stillage to a solid portion and a thin stillage liquid portion, wherein the solid portion includes a fiber cake;
separating the thin stillage into a clarified stillage, an oil emulsion, and a protein paste;
drying the fiber cake to generate a fiber animal feed product;
drying the protein paste to generate a protein animal feed product;
condensing the clarified stillage to generate a syrup;
separating oil from the oil emulsion; and
adjusting pH of the oil emulsion prior to separating the oil.
10. The method of claim 9 , wherein the adjusting comprises adjusting pH of the oil emulsion to about 8.0 to about 8.5.
11. The method of claim 9 , wherein at least around 1.33 pounds of oil is separated from the whole stillage generated from processing a bushel of corn for ethanol.
12. The method of claim 9 , further comprising combining at least some portion of the protein paste with the fiber cake.
13. The method of claim 9 , wherein the condensing comprises condensing the syrup to at least about 60% solids.
14. The method of claim 9 , wherein the protein animal feed product comprises at least about 45% protein.
15. The method of claim 9 , wherein the oil comprises at least about 97% fat.
16. The method of claim 15 , wherein the oil comprises less than 1% w/w moisture content and less than 1% w/w insolubles.
17. The method of claim 15 , wherein the oil comprises less than about 5% w/w free fatty acid content.
18. A process for fractionating whole stillage comprising:
a first separator separating whole stillage to a solid portion and a thin stillage liquid portion, wherein the solid portion comprises a fiber cake;
a three phase separator receiving the thin stillage liquid portion and separating the thin stillage liquid portion to a clarified stillage, an oil emulsion and a protein paste;
a first dryer drying the fiber cake to generate a fiber animal feed product;
a second dryer drying the protein paste to generate a protein animal feed product;
an evaporator condensing the clarified stillage to a syrup; and
a second separator separating oil from the oil emulsion,
wherein the evaporator condenses the clarified stillage to at least 60% solids.