Refining processes for a renewable oil

Abstract

The invention relates generally to methods of refining a renewable oil, such as a biofuel. In some embodiments, the invention relates to methods for the efficient removal of gums and waxes from a renewable oil.

1 . A method of reducing the cloud point of a renewable oil, the method comprising:
 providing a renewable oil, which comprises waxy impurities;   cooling the renewable oil;   adding a polymer to the cooled renewable oil:   mixing the cooled renewable oil and the polymer to form an oil-polymer mixture, which comprises solidified impurities; and   separating at least a portion of the solidified impurities from the oil-polymer mixture to form a refined renewable oil.   
     
     
         2 . The method of  claim 1 , wherein the renewable oil comprises a vegetable oil, an animal oil, or a mixture thereof. 
     
     
         3 . The method of  claim 1 , wherein the renewable oil comprises corn oil. 
     
     
         4 . The method of  claim 1 , wherein the renewable oil is a crude renewable oil. 
     
     
         5 . The method of  claim 1 , wherein the renewable oil is a renewable oil that is at least partially refined. 
     
     
         6 . The method of  claim 1 , wherein the waxy impurities comprise one or more phosphorus-containing compounds. 
     
     
         7 . The method of  claim 6 , wherein the one or more phosphorus-containing compounds comprise hydratable phosphatides, non-hydratable phosphatides, or a mixture thereof. 
     
     
         8 . The method of  claim 1 , wherein the cooling comprises cooling the renewable oil to a temperature below 5° C. 
     
     
         9 . The method of  claim 1 , wherein the cooling comprises cooling the renewable oil to a temperature below 3° C. 
     
     
         10 . The method of  claim 1 , wherein the cooling comprises cooling the renewable oil to a temperature below 1° C. 
     
     
         11 . The method of  claim 1 , wherein the polymer is an edible organic polymer. 
     
     
         12 . The method of  claim 1 , wherein the polymer is a polyvinyl polypyrrolidone polymer. 
     
     
         13 . The method of  claim 1 , wherein the separating comprises centrifuging the oil-polymer Mixture. 
     
     
         14 . The method of  claim 1 , wherein the cloud point of the refined renewable oil is at least 2° C. lower than the cloud point of the renewable oil. 
     
     
         15 . The method of  claim 1 , wherein the cloud point of the refined renewable oil is at least 4° C. lower than the cloud point of the renewable oil. 
     
     
         16 . The method of  claim 1 , wherein the cloud point of the refined renewable oil is at least 6° C. lower than the cloud point of the renewable oil. 
     
     
         17 . A method of reducing the cloud point of a renewable oil, the method comprising:
 providing a renewable oil, wherein the renewable oil comprises phosphorus-containing compounds, free fatty acids, or a combination thereof;   cooling the renewable oil;   adding a polymer to the cooled renewable oil;   binding the polymer to the phosphorus-containing compounds, the free fatty acids, or both the phosphorus-containing compounds and the free fatty acids; and   separating at least a portion of the polymer to form a refined renewable oil.   
     
     
         18 . The method of  claim 18 , wherein the renewable oil comprises a vegetable oil, an animal oil, or a mixture thereof. 
     
     
         19 . The method of  claim 18 , wherein the renewable oil comprises corn oil. 
     
     
         20 . The method of  claim 18 , wherein the renewable oil is a crude renewable oil. 
     
     
         21 . The method of  claim 18 , wherein the renewable of is a renewable oil that is at least partially refined. 
     
     
         22 . The method of  claim 18 , wherein the renewable oil comprises phosphorus-containing compounds, and the binding step comprises binding the polymer to the phosphorus-containing compounds. 
     
     
         23 . The method of  claim 23 , wherein the one or more phosphorus-containing compounds comprise hydratable phosphatides, non-hydratable phosphatides, or a mixture thereof. 
     
     
         24 . The method of  claim 18 , wherein the renewable of comprises free fatty acids, and the binding step comprises binding the polymer to the free fatty acids. 
     
     
         25 . The method of  claim 18  where the binding step comprises mixing the cooled renewable oil and the polymer to form an oil-polymer mixture. 
     
     
         26 . The method of  claim 18 , wherein the cooling comprises cooling the renewable oil to a temperature below 40° C. 
     
     
         27 . The method of  claim 18 , wherein the cooling comprises cooling the renewable oil to a temperature below 36° C. 
     
     
         28 . The method of  claim 18 , wherein the cooling comprises cooling the renewable oil to a temperature below 33° C. 
     
     
         29 . The method of  claim 18 , wherein the polymer is an edible organic polymer. 
     
     
         30 . The method of  claim 18 , wherein the polymer is a polyvinyl polypyrrolidone polymer. 
     
     
         31 . The method of  claim 18 , wherein the separating comprises centrifuging. 
     
     
         32 . The method of  claim 18 , wherein the cloud point of the refined renewable oil is at least 2° C. lower than the cloud point of the renewable oil. 
     
     
         33 . The method of  claim 18 , wherein the cloud point of the refined renewable oil is at least 4° C. lower than the cloud point of the renewable oil. 
     
     
         34 . The method of  claim 18 , wherein the cloud point of the refined renewable oil is at least 6° C. lower than the cloud point of the renewable oil.