DELIGNIN WITH OXYGEN AND BLEACHING OF LIGNOCELLULOSE BY MEANS OF ENZYME TREATMENT

摘要

PURPOSE: To provide a method for bleaching a lignocellulosic material, capable of effectively delignifying and bleaching the lignocellulosic material without affecting an environment by treating the specific lignocellulosic material with oxygen or an oxygen-containing gas and then treating the product with xylanase. CONSTITUTION: This method for bleaching a lignocellulosic material comprises treating the lignocellulosic material having xyloside bonds capable of being hydrolyzed with xylanase with oxygen or an oxygen-containing gas in an alkaline medium and then treating the product with the substantially cellulase-free xylanase in an amount sufficient to hydrolyze the hydrolyzable xyloside bonds contained in the product. It is preferable to treat the lignocellulosic material in a concentration of about 3 wt.% to about 35 wt.% in the aqueous suspension with the oxygen or the oxygen-containing gas at an oxygen fractional pressure of about 30 to about 250 psi (gauge) at about 70 to 170 deg.C for about 10-90 min.