Patent ID: 7585652
Filing Date: 2009-09-08
Classification: B01B,B01D,C01C,C01D,C05B,C05C,C05D,C05F,C12P,Y02E

Abstract:
1. A method for producing and recovering an inorganic salt slurry comprising one or more inorganic salts comprising ammonium sulfate salts, potassium sulfate salts, ammonium phosphate salts, potassium phosphate salts or mixtures thereof, and for producing alcohol from a lignocellulosic feedstock, said method comprising: a) pretreating the lignocellulosic feedstock by adding one or more than one acid selected from the group consisting of sulfuric acid and phosphoric acid to the lignocellulosic feedstock to produce a pretreated lignocellulosic feedstock product comprising xylose and cellulose; b) adding one or more than one soluble base selected from the group consisting of ammonium hydroxide, ammonia and potassium hydroxide to the pretreated lignocellulosic feedstock product, which pretreated lignocellulosic feedstock product has a pH of between about 0.4 and about 2.0, to adjust the pretreated lignocellulosic feedstock product to a pH of about 4.0 to about 6.0 to produce a neutralized feedstock product containing xylose, cellulose and one or more soluble inorganic salts, wherein said inorganic comprises salts comprise ammonium sulfate salts, potassium sulfate salts, ammonium phosphate salts, potassium phosphate salts or mixtures thereof; c) enzymatically hydrolyzing the neutralized feedstock product with cellulase enzymes to produce a hydrolyzed, neutralized product containing glucose, xylose, the inorganic salts and insoluble hydrolyzed residue; d) substantially separating the hydrolyzed, neutralized product into an inorganic salts glucose-xylose product and an insoluble hydrolyzed residue product; e) obtaining a glucose-xylose product comprising—glucose and xylose and a separate inorganic salts product comprising one or more of the inorganic salts from the inorganic salts glucose-xylose product of step d; f) producing an alcohol product by fermenting the glucose-xylose product with one or more microbes; and g) recovering the inorganic salt slurry from the inorganic salts product of step e, and concentrating the inorganic salts product.