DIGESTION METHOD FOR PULP

摘要

A digestion method for producing pulp which comprises digesting a lignocellulose material by using an alkaline digesting liquor containing polysulfides in the presence of a quinone-hydroquinone compound having a value obtained by reducing an oxidation-reduction potential observed in a form being present during digestion to a standard oxidation-reduction potential (Ea), wherein an activity of hydrogen ion is 1, in the range of 0.12 to 0.25 V to the standard hydrogen electrode potential. The method can be used for digesting a lignocellulose material to a pulp having a low kappa value in high yield, and also for reducing the amount of chemicals to be used and for reducing a load on a boiler for recovery.