Patent ID: 6063204
Filing Date: 2000-05-16
Classification: C13K

Abstract:
An improved hydrolysis system for effecting the conversions, with concentrated sulfuric acid, of pentosans in hemicellulose to pentose sugars and hexosans in cellulose and hemicellulose to hexose sugars, said system comprising an improved extruding/reacting means for effecting such hydrolysis, said extruding/reacting means comprising:housing means comprising an elongated hollow member generally closed at one end thereof and an aperture at the other end thereof, said aperture adapted for discharge of hydrolyzate and unreacted cellulose and lignin therefrom;inlet means juxtaposed the closed end of said housing means and in communication through the side wall thereof for introducing therethrough feedstock comprising cellulose and/or lignocellulose and for introducing therethrough concentrated sulfuric acid;inlet means near the end opposite the closed end thereof of said housing means and in communication through the side wall thereof for introducing therethrough steam and/or hot water;conveyor means for moving materials introduced near the closed end thereof through said housing means into contact with materials introduced through inlet means near the end opposite the closed end thereof and out through said aperture, said conveyor means comprising a twin screw, said twin screw adapted for rotation of each screw comprising same and partitioned into three zones wherein zone I is juxtaposed the closed end of said housing, zone III is juxtaposed the opposite end thereof, and zone II is between zones I and III, and wherein the degree of intermeshing between the flights of each respective screw is varied between said zones to provide for a ratio of screw conjugation between said third zone and said second zone, respectively, ranges between from about 1.056 to about 1.2, and wherein the ratio of screw conjugation between said second zone and said first zone ranges from between about 1.125 to about 1.25;driving means for causing said counter or corotation of said twin screws, said driving means juxtaposed the closed end of said housing means;means for supplying and feeding said cellulose and/or lignocellulose to the respective inlet means therefore through the wall of said housing;means for supplying and feeding said concentrated sulfuric acid to the respective inlet means therefore through the wall of said housing;means for supplying and feeding said steam to the respective inlet means therefore through the wall of said housing;means for supplying and feeding said hot water to the respective inlet means therefore through the wall of said housing; andcollection means for removal of said hydrolyzate and lignin from said aperture.