Pulping of Wheat Straw with Caustic Potash-Ammonia Aqueous Solutions and Its Kinetics  

作　　者：黄国林 张成芳 陈中胜 

机构地区：[1]Department of Chemical Engineering,East China Institute of Technology [2]Institute of Chemical Technology,East China University of Science and Technology

出　　处：《Chinese Journal of Chemical Engineering》2006年第6X期729-733,共5页中国化学工程学报（英文版）

基　　金：the Natural Science Foundation of Jiangxi Province (No.0520003).

摘　　要：A pulping technology of wheat straw with aqueous ammonia and diluent caustic potash was investigated. Because its strong alkalinity, the addition of caustic potash not only reduced the quantity of NH3 consumed and cooking time, but also enriched the black liquor with nutrients such as potassium and nitrogen, which could be used as fertilizer for agriculture. Various pulping conditions including composition of cooking liquor, liquor-to-solid ratio, maximum cooking temperature, time to reach the maximum temperature and time at the maximum temperature were studied systematically to determine the suitable pulping conditions. Results of the cooking course showed that there were three distinct delignification phases, namely, the bulk delignification phase from the beginning of cook- ing to 100℃, the supplementary delignification phase from 100℃ to 155℃ for 45min and the third delignification phase till the end of cooking. The rate of delignification was found to be first order with respect to residual lignin and 0.34 order with respect to [OH - ]. The activation energy of the delignification reaction was 29.75kJ·mol-1 and the rate equation of delignification was also obtained.A pulping technology of wheat straw with aqueous ammonia and diluent caustic potash was investigated. Because its strong alkalinity, the addition of caustic potash not only reduced the quantity of NH3 consumed and cooking time, but also enriched the black liquor with nutrients such as potassium and nitrogen, which could be used as fertilizer for agriculture. Various pulping conditions including composition of cooking liquor, liquor-to-solid ratio, maximum cooking temperature, time to reach the maximum temperature and time at the maximum temperature were studied systematically to determine the suitable pulping conditions. Results of the cooking course showed that there were three distinct delignification phases, namely, the bulk delignification phase from the beginning of cook- ing to 100℃, the supplementary delignification phase from 100℃ to 155℃ for 45min and the third delignification phase till the end of cooking. The rate of delignification was found to be first order with respect to residual lignin and 0.34 order with respect to [OH - ]. The activation energy of the delignification reaction was 29.75kJ·mol-1 and the rate equation of delignification was also obtained.

关 键 词：PULPING wheat STRAW KINETICS DELIGNIFICATION 

分 类 号：TS713[轻工技术与工程—制浆造纸工程]