Process for the chemical conversion of cellulose waste to glucose

Claim 1

In a process for the conversion of waste cellulose to glucose of the type wherein an aqueous slurry of waste cellulose is contacted with a dilute sulfuric acid catalyst at elevated temperature and pressure, the improvement wherein the acid hydrolysis comprises the steps of: continuously feeding an aqueous slurry of waste cellulose into an inlet port of a twin screw extruder; continuously reacting the cellulose with water in the presence of the sulfuric acid catalyst at elevated temperature and pressure in a reaction zone disposed in the extruder between the inlet port and an outlet port while continuously conveying same to the outlet port by continuously injecting a dilute sulfuric acid catalyst and a reactant selected from the group consisting essentially of steam and superheated water at elevated pressure into the reaction zone; and at least quasi-continuously discharging the reacted cellulose from the extruder while maintaining the elevated temperature and pressure in the reaction zone by forming a dynamic seal zone at the upstream end of the reaction zone and valving the discharge downstream of the outlet port.