METHOD OF RENDERING LIGNIN SEPARABLE FROM CELLULOSE AND HEMICELLULOSE IN LIGNOCELLULOSIC MATERIAL AND THE PRODUCT SO PRODUCED

摘要

Lignocellulosic material is packed in particulate form in a pressure vessel, steam is passed into the pressure vessel at a pressure of at least 500 psi to bring the lignocellulosic material to a temperature in the range 185 to 240.degree.C (preferably in the range 200 to 238.degree.C, more particularly 234.degree.C) in less than 60 seconds (preferably less than 45 seconds) to plasticize the lignocellulosic material. As soon as the material is plasticized it is extruded through a die to atmosphere where abrasion in the die and explosive decompression forms a particulate material like potting soil that rapidly sinks in water and from which the cellulose content is largely utilizeable, e.g. as a feed for ruminants. During extrusion the softened material is subjected to severe deformation and then severe mechanical shock thus fracturing the linkages between lignin, the hemicellulose and the cellulose. The temperature range and rapid rise thereto by the material substantially minimizes degradation of the fragile hemicellulose. The process according to the present invention converts lignocellulosic material into a substrate which is extremely easy to treat by enzymes, either as a feed for ruminant animals or for conversion to sugars and alcohols and for the solvent extraction of lignin.