Effect of hemicelluloses on pulp characteristics and use of ceramic membranes in the separation of hemicelluloses from highly alkaline industrial process stream

摘要

Effect of hemicelluloses on pulp swelling and reactivity characteristics was demonstrated. Pulp swelling, reactivity, porosity, absorption capacity were noted to decrease with increase in hemicelluloses of steeping lye. Performance of ultrafiltration ceramic membranes was studied for the separation of hemicelluloses from a highly alkaline stream of viscose process containing 17-18 wt% sodium hydroxide. Effect of process conditions like pressure and feed concentrations (hemicellulose and caustic) was studied to understand their correlation with hemicelluloses retention and permeate flux. Long-term performance of ceramic and polymeric membranes were also compared. This study indicates no adverse impact on retention of hemicelluloses with the use of ceramic membranes, however, significant increase in permeate flux could be obtained. Ceramic membranes were found to sustain the performance owing to their chemical stability.