Patent ID: 6106888
Filing Date: 2000-08-22
Classification: A23K,A23P,B29C,B29K,C12P,Y10S

Abstract:
In a process for increasing availability of sugar content and digestibility of a lignocellulosic material by contacting the lignocellulosic material with a liquid ammonia which impregnates the lignocellulosic material and then rapidly reducing the pressure to thereby expand the lignocellulosic material by gaseous expansion of the liquid ammonia to a gas which increases availability of the sugar content and the digestibility of the lignocellulosic material, the improvement which comprises:(a) injecting the liquid ammonia and the lignocellulosic material into a screw in a heated barrel having a feed throat leading to the screw in rotating contact with the barrel along part of a length of the screw so that the screw is sealed in operation, with an inlet for feeding the liquid ammonia into the feed throat under pressure to the screw and with heated outlet from the barrel adjacent to the screw;(b) compacting the liquid ammonia and lignocellulosic material by rotation of the screw in the barrel;(c) removing the liquid ammonia and the lignocellulosic material from the barrel through the outlet from the extruder so that the liquid ammonia expands explosively from the liquid to the gas in the lignocellulosic material; and(d) recovering the liquid ammonia as the gas from the lignocellulosic material.