脱墨污泥催化热解特性及动力学研究

Catalytic Pyrolysis Characteristics and Kinetics of Deinking Sludge

中文关键词:  脱墨污泥  热重分析  催化热解  动力学

Key Words:deinking sludge  thermogravimetric analysis  catalyzed pyrolysis  kinetics

中文摘要:

      利用热重分析法,对不同升温速率和催化剂条件下脱墨污泥的热解特性进行了研究,采用Coats-Redfern法对得到的热失重曲线进行模拟并建立动力学模型,计算了脱墨污泥热解的动力学参数。结果表明,脱墨污泥的热解反应为一级三段反应；在脱墨污泥催化热解的低温段(220～370℃),催化剂的催化作用由大到小的次序为：MgCl2＞CaCl2＞ZnCl2＞NaCl,MgCl2、CaCl2和ZnCl2的添加降低了低温段的活化能和最大失重速率；在高温段(600～750℃),4种催化剂的催化效果差别不大,均可使脱墨污泥热解曲线向低温区域移动,且最大失重速率明显降低。与未加催化剂的脱墨污泥相比,添加催化剂后脱墨污泥的低温段和高温段热解的活化能均有所降低,其中高温段的活化能降低50%以上。

Abstract:

      The pyrolysis characteristics of deinking sludge at different heating rates and with different catalysts were studied using thermogravimetric analysis (TG). The curves of TG & DTG were simulated using the method of Coats-Redfern integral, and the dynamical model was established,and dynamical parameters of pyrolysis of deinking sludge were calculated. The results showed that the dynamical model of the pyrolysis process was expressed by three stages parallel reaction in first-order. During the catalytic pyrolysis process of deinking sludge,for the low-temperature (220~370℃) stage,the catalytic role was∶MgCl2> CaCl2> ZnCl2>NaCl. The activation energy and the maximum value of DTG decreased by addition of MgCl2, CaCl2 and ZnCl2. MgCl2, CaCl2, ZnCl2 and NaCl presented the similar catalysis behavior in the high-temperature (600~750℃) stage, which made the pyrolysis curve of deinking sludge pyrolysis to move to the lower temperature region and the maximum value of DTG decreased obviously.Compared to the deinking sludge without catalysts,the activation energy of the deinking sludge added catalysts decreased in both low-temperature stage and high-temperature stage, the activation energy in high-temperature stage reduced by more than 50%.