Materials and methods for converting biomass to biofuel

Abstract

This disclosure provides for materials and methods for converting biomass to biofuels. The materials include a colloid mill with or without cellulase enzymes, and the methods include the use of a colloid mill and optionally cellulose enzymes to pretreat biomass for use in a biomass to biofuel production process.

What is claimed is: 
     
         1 . A method of treating a biomass/water mixture comprising cellulose and starch, comprising:
 a) contacting the biomass/water mixture to at least one amylase to hydrolyze starch contained in the biomass;   b) milling the biomass/water mixture with a high shear milling/mixing device comprising a rotor and a stator to produce milled biomass, thereby reducing the size of biomass particles in the biomass/water mixture compared to pretreatment of the biomass with a hammer mill alone,   c) following the contacting and milling, adjusting the temperature of the amylase-treated milled biomass to a temperature suitable for fermentation; and   d) fermenting the amylase-treated milled biomass in the presence of at least one cellulase that hydrolyzes the cellulose contained in the biomass to sugar.   
     
     
         2 . The method of  claim 1 , wherein the contacting occurs prior to the milling. 
     
     
         3 . The method of  claim 1 , wherein the fermenting results from yeast added to the amylase-treated milled biomass, making biofuel from biomass. 
     
     
         4 . The method of  claim 1 , wherein the amylase comprises an alpha amylase. 
     
     
         5 . The method of  claim 1 , wherein the amylase comprises a beta amylase or glucoamylase. 
     
     
         6 . The method of  claim 1 , wherein the temperature is about 30° C. to about 55° C. 
     
     
         7 . The method of  claim 1 , wherein the high shear/milling mixing device is a colloid mill. 
     
     
         8 . The method of  claim 6 , wherein the gap between the rotor and stator is adjustable. 
     
     
         9 . The method of  claim 7 , wherein the gap setting can be dynamically adjusted. 
     
     
         10 . The method of  claim 1 , wherein the high shear/milling mixing device has a gap setting between the rotor and stator of between 0.104 and 0.728 millimeters. 
     
     
         11 . The method of  claim 1 , wherein the biomass comprises grain. 
     
     
         12 . The method of  claim 1 , wherein the biomass comprises cellulosic biomass. 
     
     
         13 . The method of  claim 12 , wherein the milled biomass comprises at least 15% bone dry solids (BDS). 
     
     
         14 . The method of  claim 1 , wherein the mixture comprises 21-46% bone dry solids (BDS). 
     
     
         15 . The method of  claim 12 , wherein the biomass comprises grain and cellulosic biomass. 
     
     
         16 . The method of  claim 10 , wherein the gap setting is between 0.2 and 0.3 millimeters and the biomass is grain. 
     
     
         17 . The method of  claim 16 , wherein the grain is hammer milled whole kernel corn. 
     
     
         18 . A method of treating corn comprising both cellulose and starch, the method comprising:
 a) hammer milling whole kernel corn and mixing with water thereby generating a biomass/water mixture having a particles size mostly ranging from 100 to 1600 microns,   b) contacting the biomass/water mixture to at least one amylase to hydrolyze starch contained in the biomass,   c) milling the biomass/water mixture with a high shear milling/mixing device comprising a rotor and a stator to produce milled biomass, thereby reducing the size of biomass particles so that the biomass has a particle size mostly ranging from 100 to 800 microns,   d) adjusting the temperature of the amylase-treated milled biomass to a temperature suitable for fermentation; and   e) fermenting the amylase-treated milled biomass in the presence of at least one cellulase that hydrolyzes the cellulose contained in the biomass to sugar.   
     
     
         19 . The method of  claim 18 , wherein the fermenting results from yeast added to the amylase-treated milled biomass, making biofuel from biomass. 
     
     
         20 . The method of  claim 18 , wherein the high shear/milling mixing device has a gap setting between the rotor and stator of between 0.104 and 0.728 millimeters.