竹子EMCC蒸煮的研究

Study on EMCC process of bamboo

对福建丛生小径竹进行了实验室模拟EMCC深度脱木素蒸煮的研究.结果表明,在实验室条件下,适宜的深度脱木素蒸煮条件是:浸渍段和顺流段活性碱用量14%(Na2O计),逆流段置换温白液浓度30 g.L-1(Na2O计),蒸煮最高温度160℃,硫化度25%.在最佳工艺条件下,实验室模拟EMCC蒸煮结果为:竹浆卡伯值12.5,细浆得率44.8%,粘度1 031 mL.g-1,并且具有比常规蒸煮条件所得竹浆更好的强度性能.在实验中也发现,为了得到较低卡伯值的竹浆,用增加逆流段置换药液的浓度进行蒸煮比提高蒸煮最高温度进行蒸煮具有更好的脱木素选择性,浆的强度性能较好.

Laboratory simulated extended modified continuous cooking （EMCC） of bamboo with minor diameter in Fujian was carried out in this study. The results indicated that the optimal conditions of extended delignification at laboratory are： 14% （expressed as Na20） of active alkali charge at the impregnating stage and the current stage, 30 g·L^-1 of warm white liquor concentration at the countercurrent stage, 160 ℃ of maximum temperature, 25% of sulfidity. As a result, the Kappa number of the pulp was 12.5, the yield of screened pulp was 44. 8% and the viscosity was 1 031 mL·g^-1. Moreover, the pulp cooked by the optimal conditions has better strength property than that cooked by regular conditions. It was also found that the low Kappa number pulp cooked by the higher cooking liquor concentration in the counter-current stage has better strength property than that by the higher maximum temperature.