Reducing insoluble deposit formation in ethanol production

Abstract

The present inventors have surprisingly discovered that phytic acid tenaciously precipitates with soluble metals in food or fuel ethanol-processing fluid, producing insoluble organometallic salt deposit or scale on the processing equipment that must be removed in order to facilitate further ethanol processing. The present invention relates to converting phytic acid salts or phytates to inorganic phosphates to improve metal solubility and reduce deposition within processing equipment.

The claimed invention is: 
     
         1 . A method of reducing formation of insoluble deposits of phytic acid or salts of phytic acid in a fuel ethanol-processing equipment, the method comprising:
 adding phytase to an ethanol processing fluid in the plant containing phytic acid or salts of phytic acid under conditions suitable for converting the insoluble phytic acid or phytic acid salts to soluble products; thereby reducing the formation of deposits of insoluble phytic acid or phytic acid salts in the equipment;   wherein the reduction in the formation of deposits of insoluble phytic acid or phytic acid salts in the equipment is accomplished substantially without the addition of an acid that can break down organic phosphates and phosphonates into soluble inorganic phosphates in the presence of an oxidizer, oxidizing agent, or ultraviolet light.   
     
     
         2 . The method of  claim 1 , wherein converting comprises partial conversion of phytate to phosphate and inositol. 
     
     
         3 . The method of  claim 2 , wherein converting further comprises reacting the insoluble phytic acid salts in the presence of polar protic solvents. 
     
     
         4 . The method of  claim 3 , wherein reacting the insoluble phytic acid salts in the presence of polar protic solvents comprises reacting in the presence of ethanol and water. 
     
     
         5 . The method of  claim 1 , wherein the ethanol processing fluid comprises fermentation slurry, beer, whole stillage, centrate, thin stillage, backset, or mixture thereof 
     
     
         6 . The method of  claim 1 , wherein adding comprises introducing the phytase into the ethanol processing fluid at a temperature from about 20° C. to about 80° C. 
     
     
         7 . The method of  claim 1 , wherein adding comprises introducing the phytase for a residence time sufficient for complete reaction of the phytase with the insoluble phytic acid salts. 
     
     
         8 . The method of  claim 1 , wherein adding comprises introducing the phytase for a residence time from about 2 minutes to about 1200 minutes. 
     
     
         9 . The method of  claim 1 , further comprising analyzing an insoluble deposit in the equipment. 
     
     
         10 . The method of  claim 9 , wherein analyzing comprises detecting phytic acid or phytate. 
     
     
         11 . The method of  claim 10 , wherein analyzing comprises detecting magnesium phytate. 
     
     
         12 . The method of  claim 1 , wherein equipment in which deposit formation is reduced comprises a beer column. 
     
     
         13 . The method of  claim 1 , comprising adding phytase to a concentration of 500 ppm or less in the ethanol processing fluid. 
     
     
         14 . The method of  claim 1 , comprising adding phytase to a concentration of 2500 U/L ppm or less in the ethanol processing fluid.