Study On Technology Of Pre-Hydrolysis And Enzymatic Pretreament In Bagasse Dissolving Pulp Preparation Process

This research used bagasse as raw material, through sulfuric acid pre-hydrolysis and xylanase biological treatment process, combined with the conventional sulfate cooking and D0EpD1bleaching process, preparative bagasse dissolving pulp, yield was33.60%, a-cellulose content was93.47%, pentosan content was3.07%, ash content was0.08%, and brightness was85.18%ISO. The mechanism of pre-hydrolysis and xylanase biological treatment was studied by fiber quality analysis, infrared spectrum analysis, scanning electron microscopy (SEM) and high performance liquid chromatography (HPLC). This provided the theoretical foundation for the application of xylanase in dissolving pulp preparation process. The results were as follows:1.The optimum process conditions of sulfuric acid pre-hydrolysis were as below:Acid dosage0.10%,150℃,90min. After pre-hydrolysis, cellulose content of the raw materials increased18.45%,and pentosan decreased14.49%. 2.The optimum process conditions of enzyme biological treatment were as below:Enzyme dosage3FXU/g, pH5.0,45℃,120min. After enzyme biological treatment, cellulose content of the bagasse pulp increased4.13%, and pentosan content reduced2.25%.3. The fiber quality analysis showed fiber length and width were reduced, the tiny fiber content was decreased after acid pre-hydrolysis; HPLC analysis showed the optimum acid pre-hydrolysis process which can reduce the inevitable cellulose degradation effectively, hemicelluloses were hydrolyzed furthest at the same time; FTIR spectrum analysis showed acid pre-hydrolysis process can dissolve a lot of hemicelluloses; SEM observation revealed that the fiber surface was clean, the cell outline was clear, the grooves of fiber surface were obvious, cracks and holes were observed.4.The fiber quality analysis showed fiber length increased, width decreased, and tiny fiber content drooped after enzyme treatment; HPLC analysis showed the optimum xylanase biological treatment process which can further remove the residual xylan of pulp; FTIR spectrum analysis showed enzyme treatment process can destroy LCC structure thereby dissolve bits of lignin; SEM observation revealed that cracks and grooves on the fiber surface were obvious, fold degree were deepened, a large number of pitting were observed.