Method and systems for enhancing oil recovery from ethanol production byproducts
View Patent ↗Methods and related systems efficiently and effectively recover a significant amount of valuable, useable oil from byproducts formed during a dry milling process used for producing ethanol. The method may include forming a concentrate from the byproduct and recovering oil from the concentrate. The step of forming the concentrate may comprise evaporating the byproduct using a multi-stage evaporator, as well as recovering the oil before the final stage of the evaporator. Further, the step of recovering oil from the concentrate may comprise using a centrifuge and, in particular, a disk stack centrifuge. Other aspects include related methods and subsystems for recovering oil.
1. A method for recovering oil in a dry milling process for producing ethanol from corn, the method comprising:
separating a whole stillage byproduct of the dry milling process with a separator into a distillers wet grains fraction, a thin stillage fraction, and an oily fraction;
combining the oily and thin stillage fractions;
evaporating the combined fractions of the oily fraction and the thin stillage fraction to remove moisture and form a concentrate of the oily and thin stillage fractions;
recovering oil from the concentrate with an additional separator;
evaporating the concentrate to further reduce the moisture content of the concentrate and form an evaporated concentrate; and
mixing the evaporated concentrate with the further reduced moisture content with the distillers wet grains fraction.
2. The method of claim 1 , further comprising adding a chemical additive during the step of recovering the oil from the concentrate.
3. The method of claim 2 , wherein adding the chemical additive comprises adjusting a pH of the concentrate.
4. The method of claim 2 , wherein adding the chemical additive comprises adding enzymes.
5. The method of claim 1 , wherein recovering oil from the concentrate with the additional separator further recovers an additional distillers wet grains fraction and an additional thin stillage concentrate fraction.
6. The method of claim 5 , wherein recovering oil from the concentrate with the additional separator comprises recovering the oil with a horizontal centrifugal three phase decanter.
7. The method of claim 5 , wherein recovering oil from the concentrate with the additional separator comprises recovering the oil with disc stack centrifuge.
8. The method of claim 5 , further comprising evaporating the additional distillers wet grains fraction and the additional thin stillage concentrate fraction to further reduce the moisture content therein.
9. A method for recovering oil in a dry milling process for producing ethanol from corn, the method comprising:
evaporating a thin stillage fraction to form a thin stillage concentrate with a reduced moisture content relative to the thin stillage fraction;
recovering oil from the thin stillage concentrate with a horizontal centrifugal three phase decanter;
evaporating the thin stillage concentrate to further reduce the moisture content of the thin stillage concentrate and form an evaporated thin stillage concentrate; and
mixing the evaporated thin stillage concentrate with a distillers wet grains fraction.
10. The method of claim 9 , further comprising adding a chemical additive during the step of recovering the oil from the concentrate.
11. The method of claim 10 , wherein adding the chemical additive comprises adjusting a pH of the concentrate.
12. The method of claim 10 , wherein adding the chemical additive comprises adding enzymes.