IMPROVED PROCESS AND COMPOSITION FOR DELIGNIFYING A LIGNOCELLULOSIC MATERIAL

摘要

A process for delignifying a lignocellulosic material comprising exposing the material at pH 6.0 to 9.5 to a mixture of monopersulfuric acid and a ketone of formula (I), wherein R<1> and R<2> are independently selected from the group consisting of alkyl and aryl, or R<1> and R<2> together form a carbocycle. Also disclosed is a kraft pulp delignification mixture comprising in combination: (a) water; (b) from about 0.05 to about 0.3 moles per liter of a ketone as above; (c) from about 0.0008 to about 0.50 moles per liter of monopersulfuric acid; and (d) sufficient buffer to maintain the pH between about pH 6 and about pH 9.5.