Process and method for the recovery of oil from the processing of grains into biofuels and other chemicals

Abstract

A method of recovering an extraction aid from distillers corn oil, by directing stillage containing distillers oil and an extraction aid to a centrifugal separator, recovering a light phase from the centrifugal separator, the light phase containing at least a portion of the distillers oil and at least a portion of the extraction aid, cooling the light phase and causing a precipitate to form, and recovering a precipitate from the cooled light phase containing at least a portion of the extraction aid. A method of recovering distillers oil.

What is claimed is: 
     
         1 . A method of recovering an extraction aid from a stream containing oil and an extraction aid, including the steps of:
 directing a stream containing oil and an extraction aid to a separator;   recovering a light phase from the separator, the light phase containing at least a portion of the oil and at least a portion of the extraction aid;   cooling the light phase and causing a precipitate to form; and   recovering the precipitate from the cooled light phase.   
     
     
         2 . The method of  claim 1 , further including the step of directing and recycling at least a portion of the recovered precipitate to the feed of a separator. 
     
     
         3 . The method of  claim 1 , wherein said cooling step is further defined as cooling the light phase to a temperature at or below about 120 degrees F. 
     
     
         4 . The method of  claim 3 , wherein said cooling step is further defined as cooling the light phase to a temperature at or below about 80 degrees F. 
     
     
         5 . The method of  claim 1 , wherein the stream containing oil is from a fermentation process that produces ethanol. 
     
     
         6 . The method of  claim 1 , wherein the feedstock to a fermentation process producing the stream is one or more of corn and milo. 
     
     
         7 . The method of  claim 1 , where the stream containing oil and an extraction aid is directed to a centrifugal separator. 
     
     
         8 . The method of  claim 7 , further including concentrating the stream containing oil before said directing step. 
     
     
         9 . The method of  claim 8 , wherein said concentrating step is performed by a method chosen from the group consisting of evaporation, filtration, dissolved air flotation, and combinations thereof. 
     
     
         10 . The method of  claim 1 , further including the step of concentrating the precipitate prior to directing at least a portion of concentrated precipitate to the feed of a centrifuge. 
     
     
         11 . The method of  claim 10 , wherein said concentrating step is performed by a method chosen from the group consisting of centrifugation, filtration, solvent extraction, and combinations thereof. 
     
     
         12 . The method of  claim 2 , wherein the separator is a centrifugal separator. 
     
     
         13 . The method of  claim 2 , wherein said recycling step improves the separation efficiency of the separator. 
     
     
         14 . The method of  claim 1 , wherein the stream containing oil is stillage from a grain process. 
     
     
         15 . The method of  claim 14 , wherein the grain process is a fermentation process. 
     
     
         16 . The method of  claim 15 , wherein the fermentation process produces ethanol. 
     
     
         17 . The method of  claim 14 , wherein the stillage is concentrated. 
     
     
         18 . The method of  claim 17 , wherein the stillage is concentrated by one of more of the following means: evaporation, dissolved air flotation, filtration, centrifugation and combinations thereof. 
     
     
         19 . A method of recovering an extraction aid from distillers oil, including the steps of:
 directing stillage containing oil and an extraction aid to a separator   recovering a light phase from the separator, the light phase containing at least a portion of the oil and at least a portion of the extraction aid.   cooling the light phase and causing a precipitate to form   recovering the precipitate from the cooled light phase containing at least a portion of the extraction aid.   
     
     
         20 . The method of  claim 19 , further including directing the recovered precipitate to the feed of the separator 
     
     
         21 . A method of recovering an extraction aid from distillers oil, including the steps of:
 directing whole stillage to a first separator   separating the whole stillage into wet cake and thin stillage   directing the thin stillage to a second separator   separating the thin stillage into a light phase containing oil and an extraction aid and heavy phase   cooling the light phase and causing a precipitate to form and   recovering the precipitate   
     
     
         22 . The method of  claim 21 , further including concentrating the thin stillage prior to directing to the second separator. 
     
     
         23 . The method of  claim 22 , wherein the thin stillage is concentrated by one of more of the following means: evaporation, dissolved air flotation, filtration, centrifugation and combinations thereof. 
     
     
         24 . The method of  claim 21 , further including directing the recovered precipitate to the whole stillage. 
     
     
         25 . The method of  claim 24 , wherein the addition of recovered precipitate increases the partitioning of oil to the thin stillage. 
     
     
         26 . The method of  claim 24 , wherein the method of the first separator is chosen from the following: centrifuge, decanting centrifuge, filtration, pressure screen, membrane, filter press, belt press, or combinations thereof. 
     
     
         27 . The method of  claim 24 , wherein the method of the second separator is chosen from the following: centrifuge, decanting centrifuge, solvent extraction, membrane, filtration or combinations thereof. 
     
     
         28 . A method of producing a distillers oil low in impurities, including the steps of:
 directing stillage containing oil to a separator,   separating the stillage into a light phase and a heavy phase,   cooling the light phase and causing a precipitate to form and   recovering an oil from the light phase.   
     
     
         29 . The method of  claim 28 , wherein the level of impurities in the oil is less than the level in the light phase. 
     
     
         30 . The method of  claim 29 , wherein said impurities include one or more of the following: water, sodium, calcium, magnesium, potassium, iron, nickel, silicon, phosphorous and sulfur. 
     
     
         31 . The oil of  claim 28 . 
     
     
         32 . A distillers oil with one or more of the following: phosphorous content of less than 10 ppm, a total content of sodium, potassium, magnesium, and potassium of less than 10 ppm, or combinations thereof.