Effects of Soluble Anthraquinone Application on Prehydrolysis Soda Cooking of Acacia crassicarpa Wood

Abstract

Acacia crassicarpa has a potential source as a renewable forest material in Indonesia. This research clarified the conditions to produce dissolving pulp with suitable properties from A. crassicarpa wood by prehydrolysis at 150℃ for 3 h and soda cooking at 160℃ for 3 h with application of 0.1％ soluble anthraquinone （SAQ：1,4-dihydro-9,10-dihydroxyanthracene sodium salt）. The presence of SAQ in soda cooking exhibited a significant increase in pulp yield （1.8％） compared to kraft cooking at a given kappa number （approximately 11）. The bleaching ability of the soda-SAQ pulp in elemental chlorine-free process with peroxymonosulfuric acid （O-D₀/P_sa-E_p-D₁ sequence） was sufficiently good for dissolving pulp properties. The α-cellulose content, brightness, viscosity and ash content were 94.1％, 88.1％ ISO, 10.3 mPa·s, and 0.02％, respectively.