Biomass pretreatment process

Abstract

The process for the treatment of ligno-cellulosic biomass comprises the steps of: A) Soaking a ligno-cellulosic biomass feedstock in vapor or liquid water or mixture thereof in the temperature range of 100 to 210° C. for 1 minute to 24 hours to create a soaked biomass containing a dry content and a first liquid; B) Separating at least a portion of the first liquid from the soaked biomass to create a first liquid stream and a first solid stream; wherein the first solid stream comprises the soaked biomass; and C) Steam exploding the first solid stream to create a steam exploded stream comprising solids and a second liquid.

We claim: 
     
         1 . A composition of ligno-cellulosic biomass comprising a solid, a liquid, furfural, an amount of C5's based upon the amount of arabinan and xylan and the monomers, dimers, oligomers and polymers of arabinose and xylose in the liquid and solid of the composition, an amount of C6's based upon the glucan content which includes the monomers, dimers, oligomers and polymers of glucan in the liquid and solid of the composition and wherein the ratio of the amount of C5's to the amount of C6's is less than 0.50 or 0.44 and the ratio of the amount of the furfural to the amount of C5's and C6's added together is less than a number selected from the group consisting of 0.0060, 0.0050, 0.0040, 0.0030, 0.0020, 0.0010, and 0.0009. 
     
     
         2 . The composition of  claim 1 , wherein the amount of the solids in the composition by percent weight of the composition are in a range selected from the group consisting of 11 to 99, 14 to 99, 16 to 99, 19 to 99, 21 to 99, 24 to 99, 26 to 99, 29 to 99, 31 to 99, 36 to 99, and 41 to 99. 
     
     
         3 . The composition of  claim 1 , wherein the amount of the solids in the composition are in the range of 3 to 85% by weight of the composition. 
     
     
         4 . A composition of ligno-cellulosic biomass comprising a solid, a liquid, furfural, an amount of C5's based upon the amount of arabinan and xylan and the monomers, dimers, oligomers and polymers of arabinose and xylose in the liquid and solid of the composition, an amount of C6's based upon the glucan content which includes the monomers, dimers, oligomers and polymers of glucan in the liquid and solid of the composition wherein the ratio of the amount of C5's to the amount of C6's is greater than 0.50 and the ratio of the amount of the furfural to the amount of C5's and C6's added together is less than a number selected from the group consisting of 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, 0.006, 0.005, 0.004, 0.003, 0.002, and 0.001. 
     
     
         5 . The composition of  claim 4 , wherein the amount of the solids in the composition by percent weight of the composition are in a range selected from the group consisting of 11 to 99, 14 to 99, 16 to 99, 19 to 99, 21 to 99, 24 to 99, 26 to 99, 29 to 99, 31 to 99, 36 to 99, and 41 to 99. 
     
     
         6 . The composition of  claim 4 , wherein the amount of the solids in the composition are in the range of 3 to 85% by weight of the composition.