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 insoluble material formation in equipment that contacts food or fuel ethanol-processing fluids, the method comprising:
 adding an agent to the ethanol-processing fluids after fermentation;   converting the insoluble material to a soluble residue by action of the agent; and   removing the soluble residue from the equipment that contacts the ethanol-processing fluids.   
     
     
         2 . The method of  claim 1 , wherein the insoluble material comprises phytate; and
 adding comprises adding phytase to the ethanol-processing fluids after fermentation.   
     
     
         3 . The method of  claim 1 , wherein adding an agent comprises adding an enzyme to the ethanol-processing fluids. 
     
     
         4 . The method of  claim 3 , wherein the enzyme comprises an enzyme having phytase activity. 
     
     
         5 . The method of  claim 1 , wherein converting comprises partial conversion of phytate to phosphate and inositol. 
     
     
         6 . The method of  claim 5 , wherein converting further comprises reacting the insoluble material in the presence of polar protic solvents. 
     
     
         7 . The method of  claim 6 , wherein reacting the insoluble material in the presence of polar protic solvents comprises reacting in the presence of ethanol and water. 
     
     
         8 . The method of  claim 1 , wherein converting comprises acid specific digestion in the presence of a strong oxidizer. 
     
     
         9 . The method of  claim 1 , wherein converting comprises acid digestion in the presence of ultraviolet light. 
     
     
         10 . The method of  claim 1 , wherein adding an agent to the ethanol-processing fluid comprises adding the agent to fermentation fluid. 
     
     
         11 . The method of  claim 10 , wherein adding an agent to fermentation fluid further comprises adding the agent to thin stillage, backset, or mixture thereof. 
     
     
         12 . The method of  claim 10 , wherein adding an agent to fermentation fluid further comprises adding the agent to fermentation slurry, beer, whole stillage, thin stillage, backset, centrate, or mixture thereof. 
     
     
         13 . The method of  claim 1 , wherein adding comprises introducing the agent into the ethanol-processing fluid at a temperature from about 20° C. to about 80° C. 
     
     
         14 . The method of  claim 1 , wherein adding comprises introducing the agent into the ethanol-processing fluid at a pH of about 4.0. 
     
     
         15 . The method of  claim 1 , wherein adding comprises introducing the agent for a residence time sufficient for complete reaction of the agent with the insoluble material. 
     
     
         16 . The method of  claim 1 , wherein adding comprises introducing the agent for a residence time from about 2 minutes to about 1200 minutes. 
     
     
         17 . The method of  claim 1 , further comprising analyzing the insoluble deposit in the equipment. 
     
     
         18 . The method of  claim 17 , wherein analyzing comprises detecting phytic acid or phytate. 
     
     
         19 . The method of  claim 18 , wherein analyzing comprises detecting magnesium phytate. 
     
     
         20 . A method of reducing formation of insoluble deposits in equipment that contacts food or fuel ethanol-processing fluids, the method comprising:
 adding an enzyme with phytase activity to the ethanol-processing fluids after fermentation;   converting the phytate to orthophosphate by action of the enzyme; and   removing the soluble orthophosphate from the equipment.   
     
     
         21 . The method of  claim 20 , further comprising identifying the insoluble deposit in the ethanol-processing fluids as phytic acid or a salt of phytic acid. 
     
     
         22 . The method of  claim 20 , wherein adding an enzyme with phytase activity to fermentation fluid further comprises adding the enzyme to fermentation slurry, beer, whole stillage, thin stillage, backset, centrate, or mixture thereof. 
     
     
         23 . The method of  claim 20 , wherein adding comprises introducing the enzyme into the ethanol-processing fluid at a temperature from about 20° C. to about 80° C. 
     
     
         24 . The method of  claim 20 , wherein adding comprises introducing the enzyme into the ethanol-processing fluid at a pH of about 3.0 to 9.0. 
     
     
         25 . The method of  claim 1 , wherein adding comprises introducing the agent into the ethanol-processing fluid at a temperature from about 30° C. to about 55° C.