改性介孔分子筛Zn-MCM-41对纤维素催化热解的影响

Effect of modified mesoporous zeolite of Zn-MCM-41 on catalytic pyrolysis of cellulose

采用热重分析，考察了不同硅锌比和晶化温度条件下制备的分子筛Zn—MCM一41对纤维素催化热解的催化作用效果．结果表明：在Zn—MCM-41催化作用下，纤维素热解温度降低，最大失重速率和失重率增加；硅锌比、晶化温度对纤维素热解影响明显；随硅锌比的增大，纤维素的最大失重速率和失重率呈现先升后降的趋势，当硅锌比为50时达到最大值；随晶化温度的升高，纤维素的最大失重速率和失重率同样呈现先增后减的趋势，当晶化温度在llO～120℃范围时为最大值．利用Ozawa动力学模型描述纤维素催化热解过程，表明Zn—MCM一41的存在改变了热解反应途径，表现出反应活化能的增加；制备Zn—MCM-41的最优条件是硅锌比50：1，晶化温度120℃．

Catalysis pyrolysis of cellulose was investigated over mesoporous zeolite of Zn-MCM-41 pre pared from different ratios of Si/Zn and crystallization temperatures by using a thermal gravimetric ana lyzer. The results show that the temperature of cellulose pyrolysis decreases and the maximum loss rate and weight loss percentage of cellulose increase under the condition of Zn-MCM-41 the catalytic pyrolysis of cellulose is influence there is a maximum value for the maximum we weight zeolite; by the ratio of Si/Zn and crystallization temperature; ht loss rate and weight loss percentage of cellulose with the change of the ratio of Si/Zn and crystallization temperature,which happens at a ratio of Si/Zn of 50 and crystallization temperatures ranging from 110 ℃ to 120 ℃. The kinetics study of cellulose catalytic pyrolysis described by Ozawa model shows that the path of cellulose pyrolysis has been changed with Zn-MCM-41,indicating activation energy of this reaction increasing,and the optimum process of pre- paring Zn-MCM-41 is Si/Zn of 50： 1,and crystallization temperature of 120 ℃.