Abstract:

Conditions of hemicellulose pre\|extraction  and the impact of it on sodaanthraquinone cooking pulp properties were discussed. The results shows temperature and extraction time influence the mass concentration of reducing sugar in hydrolyzate and the yield of rice straw. Based on  two points of the mass concentration of reducing sugar and the yield of rice straw, the optimum condition of preextraction was 1 h of heating time and 1.5 h of holding time at 150 ℃. The mass concentration of reducing sugar in hydrolyzate was 4.65 g/L. Under the same condition, Kappa number of rice straw pulping after preextraction was 2.56 higher than that of nonextracted rice straw pulping.

Key words: hemicellulose, preextraction, rice straw, pulp properties