Patent ID: 8563277

Claim:
A method of producing a composition comprising C5 and C6 saccharides and low levels of an inhibitor compound from a biomass composition comprising cellulose, hemicellulose, and/or lignocellulose, the method comprising: (a) pretreating the biomass composition comprising cellulose, hemicellulose, and/or lignocellulose to produce a pretreated biomass composition comprising a mixture of solid particles, wherein at least 50% of the solid particles are less than 1.5 mm in a dimension, and C5 monosaccharides and/or disaccharides in a yield that is at least 50% of a theoretical maximum, wherein pretreating produces low levels of the inhibitor compound and comprises: (i) hydration of the biomass composition in an acid medium to produce a hydrated biomass composition, (ii) mechanical size reduction of the hydrated biomass composition to produce the mixture of solid particles, and (iii) heating the hydrated biomass composition for a time sufficient to produce the pretreated biomass composition comprising C5 monosaccharides and/or disaccharides in the yield that is at least 50% of the theoretical maximum while producing low levels of the inhibitor compound; and (b) hydrolyzing the pretreated biomass composition with one or more enzymes for a time sufficient to produce the composition comprising C5 and C6 saccharides and low levels of the inhibitor compound.