Hemicelluloses Separation from Black Liquor

Abstract

The black liquor from NaOH-AQ pulping of bagasse was treated by conventional alcohol precipitation method to separate hemicelluloses. In the system of alcohol/methanol, some parameters which may affect the hemicelluloses precipitation were discussed, such as mixed alcohols charge, temperature, pH and time. The obtained hemicelluloses were analyzed by FT-IR. The results showed that compared with conventional separation system of hemicelluloses by alcohol, when the Valcohol : Vmethanol was 5:5 and pH was 4.5 at 45°C, the consumption of alcohols was decreased by 17% to 30%. Moreover, the addition of flocculants of PAC/A PAM in the process of hemicelluloses separation, the consumption of organic solvents would be further decreased.