(57) A process and apparatus for the conversion of waste cellulose to glucose wherein waste cellulose is acid hydrolyzed includes continuously feeding waste cellulose into a inlet port with a twin screw extruder, continuously reacting the cellulose with water in the presence of an acid catalyst at elevated temperature and pressure in a reaction zone disposed in the extruder between the inlet port and an outlet port 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.