Cooling and processing materials

Abstract

Systems and methods for cooling and processing materials are disclosed.

What is claimed is: 
     
         1 . A method comprising:
 grinding or comminuting a biomass material;   cooling the ground or comminuted biomass material to 280° K (6.85° C.) or less to reduce the recalcitrance of the material;   after cooling, grinding or comminuting the cooled biomass material; and   after the second grinding or comminuting step, processing the material to produce a product that is chemically different from the biomass material.   
     
     
         2 . The method of  claim 1  wherein processing comprises contacting the material with an enzyme and/or a microorganism. 
     
     
         3 . The method of  claim 1  wherein the biomass material comprises a lignocellulosic material. 
     
     
         4 . The method of  claim 2  wherein the material comprises cellulose and contacting the material comprises utilizing an enzyme to saccharify the cellulose. 
     
     
         5 . The method of  claim 1  further comprising irradiating the biomass material. 
     
     
         6 . The method of  claim 5  wherein the biomass material has been irradiated prior to cooling. 
     
     
         7 . The method of  claim 1  wherein cooling is performed in a freeze grinding or freeze milling device. 
     
     
         8 . The method of  claim 2  wherein contacting the material comprises utilizing a microorganism to produce an alcohol. 
     
     
         9 . The method of  claim 8  wherein the alcohol comprises ethanol or n-butanol. 
     
     
         10 . The method of  claim 1  wherein cooling comprises cooling the material to a temperature below the brittle point of the material. 
     
     
         11 . The method of  claim 5  wherein cooling is performed prior to irradiating. 
     
     
         12 . The method of  claim 11  further comprising cooling again after irradiating. 
     
     
         13 . The method of  claim 1  wherein cooling comprises temperature cycling the starting material. 
     
     
         14 . The method of  claim 1  wherein the biomass material has a bulk density of less than 0.3 g/cm 3 . 
     
     
         15 . The method of  claim 6  wherein irradiating is performed using an electron beam. 
     
     
         16 . The method of  claim 6  wherein the biomass material receives a dose of radiation of from about 10 MRad to 100 Mrad. 
     
     
         17 . The method of  claim 6  wherein the biomass material receives a dose of radiation of from about 30 MRad to 90 MRad. 
     
     
         18 . The method of  claim 1  wherein the biomass material is selected from the group consisting of wood, grasses, rice hulls, bagasse, jute, hemp, flax, bamboo, sisal, abaca, straw, corn cobs, coconut hair, algae, seaweed, and mixtures of any of these. 
     
     
         19 . The method of  claim 1  wherein cooling comprises cooling the biomass material to 260° K (−13.2° C.) or less. 
     
     
         20 . The method of  claim 1  wherein the biomass material has a bulk density of less than 0.8 g/cm 3 .