Processes and systems for recovering oil from fermentation products

Abstract

Processes and systems for recovering oil from a fermentation product are provided that optimize oil recovery during fermentation. The processes and systems described herein introduce a gas into the fermentation product in order to cause the oil within the fermentation product to separate therefrom, thereby facilitating its subsequent recovery. The processes and systems described herein can maximize the amount of oil that can be recovered during fermentation.

1 - 11 . (canceled) 
     
     
         12 . A method for recovering an oil from whole stillage the method comprising: (a) fermenting a whole stillage to thereby produce a fermentation product comprising an oil; (b) introducing a gas into the fermentation product to thereby form an oil-poor component and an oil-rich component; and (c) separating the oil-rich component from the oil-poor component to thereby produce a recovered oil-rich product. 
     
     
         13 . The method of  claim 12 , wherein the gas is introduced into the fermentation product at a rate of 5 to 1,000 cm.sup.3/min. 
     
     
         14 . The method of  claim 13 , wherein at least a portion of the introducing of step (b) occurs during at least a portion of the fermenting of step (a 
     
     
         15 . The method of  claim 14 , wherein the fermenting of step (a) and the introducing of step (b) occur in a container comprising an agitator, wherein the <agitator operates at a predetermined fermentation agitation rate during the fermenting of step (a) and a predetermined gas agitation rate during the introducing of step (b), wherein the gas agitation rate is at least 50 percent less than the fermentation agitation rate. 
     
     
         16 . The method of  claim 13 , wherein the gas is introduced over a period of 0.1 to 24 hours. 
     
     
         17 . The method of  claim 12 , wherein the recovered oil-rich product comprises at least about 75 weight percent of oil 
     
     
         18 . The method of  claim 12 , wherein the recovered oil-rich product comprises at least about 50 percent of the oil originally present in the fermentation product 
     
     
         19 . The method of  claim 12 , wherein at least a portion of the gas is produced by a gas sparger, gas diffuser, aeration turbine, venturi tube, or a combination thereof. 
     
     
         20 - 26 . (canceled) 
     
     
         27 . A system for recovering an oil from biomass, the system comprising: (a) a fermentation tank configured to ferment an oil-containing biomass feedstock into a fermentation product; (b) a gas injection system, in fluid communication with the fermentation tank, wherein the gas injection system is configured to introduce a gas into the fermentation product thereby separating it into an oil-poor component and oil-rich component; and (c) an oil recovery system in fluid communication with the fermentation tank, wherein the oil, recovery system is configured to recover the oil-rich component. 
     
     
         28 . The system of  claim 27 , further comprising an oil purification system in fluid communication with the oil recovery system, wherein the oil purification system is configured to remove solids and non-oil components from the oil-rich component. 
     
     
         29 . The system, of  claim 27 , further comprising a holding tank in fluid communication between the fermentation tank and the oil recovery system, wherein the holding tank is configured to hold the fermentation product from the fermentation tank 
     
     
         30 . The system of  claim 29 , wherein the gas injection system is in fluid communication with the holding tank and is configured to introduce the gas into the holding tank.