The use of green liquor and its derivatives in improving kraft pulping

In addition to white liquor, a portion of green liquor can be added to the early stages of kraft cooking as a new source of extra sulfide to improve kraft cooking selectivity. Pilot plant trials using displacement batch cooking showed positive results from using green liquor or mother liquor from carbonate crystallization in impregnation. Improved bleachability and pulp strength was achieved with green liquor charges that are practical for kraft mills. Application : green liquor can be used as extra cooking liquor in liquor-displacement kraft batch cooking to enhance pulp bleachability and strength using existing equipment and processes.