Modification of Alkaline Pulping to Facilitate the Isolation of Aliphatic Acids Part 2. Sodium Hydroxide Pretreatment of Birch Wood

Abstract

A modified pulping system of birch wood (Betula verrucosa / Betula pubesaena) involving alkaline pretreatment of the chips was studied as a possibility for a facilitated recovery of the carbohydrate degradation products (aliphatic acids). Although a proper pretreatment resulted in a fairly extensive formation of aliphatic acids compared with the lignin dissolution, delignification was retarded in the pulping stage (kraft or soda-anthraquinone) and the pulp yield was somewhat lower (0.5 – 1 % of wood). Data are reported for the composition of aliphatic acids in liquors after pretreatments.