The Reed Ethanol Countercurrent Pulping Glycans Degradation Regulation And Application

This article presents the performance of the yield and, hardness of pulps, and properties of the waste liquor from each cooking stage of reed three-stage counter-current batch cooking with ethanol-water process. The SEM and IR-FT were employed to gain more understanding on the change of lignin on fiber surface and the structural change of lignin separated from waste liquor of each stage. The results show that by three-stage counter-current batch cooking with ethanol-water, the quality of the pulp has good performance. The screened pulp yield is49.72%and Kappa number is25.6. The degradation and removal of lignin and glycans occurs mainly in the first stage. The first stage played a major role, while Sec and third cooking stages play a supporting role. After the first stage cooking, most fibroblasts did not reach the fiber separation point. After the second and third stage cooking, the fiber separation change better and hardness of pulps decrease. Maximum insulation temperature reduce20℃, fine pulp yield increased by3.9percentage points, and the Kappa number decreased11.0than the single-stage digester. Countercurrent cooking can give full play to reuse catalysis of organic acids in the cooking liquid, play extraction washing slurry role, and resolves this problem of the ethanol pulping slurry washing difficult to achieve cooking-pulp washing integration.The delignification waste liquor from the first cooking stage of reed three-stage counter-current batch cooking with ethanol-water process recycled, using preliming, sulfitation and activated carbon absorption combination method decolor the waster liquor. The preliming temperature, calcium superphosphate consumption, pH, Na2SO3consumption for sulfitation, column height for activated carbon absorption and velocity have effects on decolorization. The results indicated that the50mL undecolorization waste liquor have the best decolorizing effect, when the preliming temperature was80℃, calcium superphosphate consumption were1g, pH=7, Na2SO3consumption were0.04mol, column height were14cm, velocity was2mL/min. The decolorization rate got to98.1%. The degradation of sugar precipitated of0.247g from decolorization waste liquor, distilled sugar0.292g, sugar recovery rate of53.9%.This article determined the reed ethanol slurry’s glucose and xylose content in different holding time by ion chromatography. The study showed that:the glucose and xylose of reed ethanol pulp degradation reactions are first-order reaction; Removal rate from the the glycan degradation of the process point of view, cellulose (polydextrose) is divided into two stages: the insulation began about90min to slow prime prolapse stage; quickly for90min to insulation endto prolapse stage; hemicellulose (xylan) removal rate is also divided into two stages:the insulation began about60min to slow prolapse stage; from the end of the insulation60min to insulation, for fast prolapse stage. Cellulose quick removal and slow removal of the activation energy difference is smaller, were17.76kJ·mol-1and26.32kJ· mol-1, hemicellulose rapid removal and slow removal of the activation energy difference were37.77kJ·mol-1and9.08kJ·mol-1. The insulation post-cellulose and hemicellulose degradation rate than fast, not too long insulation.