MATERIALS AND METHODS FOR CONVERTING BIOMASS TO BIOFUEL
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.
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.