School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, PR China.
School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Waste Manag. 2020 Jul 15;113:51-61. doi: 10.1016/j.wasman.2020.05.039. Epub 2020 Jun 4.
Much attention has been devoted to disposing traditional-sized poly(methyl methacrylate) (PMMA) waste by pyrolysis for methyl methacrylate (MMA). The pyrolysis of micron-sized PMMA waste, which may be different from that of traditional-sized PMMA waste, received little concern. The present study investigated the kinetics and volatile products of micron-sized PMMA waste pyrolysis in inert atmosphere using thermogravimetry and Fourier transform infrared analysis. A global optimization algorithm namely Shuffled Complex Evolution (SCE) was employed to simultaneously optimize the kinetic parameters. Results indicated that one shoulder and one peak occurred in the MLR variations with temperature. The values of the MLR at the shoulder and peak, the average MLR all increased with the heating rate. The optimized kinetic parameters by SCE can be utilized to well reproduce the experimental thermogravimetric data. The values of activation energy and natural logarithm of pre-exponential factor were in the range of 235.95-248.61 kJ/mol and 16.96-28.76 min, respectively. The value of activation energy of micron-sized PMMA waste pyrolysis under the present study was greater than that of the traditional-sized PMMA pyrolysis in the previous studies. MMA and CO were the major volatile products generated from the micron-sized PMMA waste pyrolysis. The volatile products yield at peak was much larger than that at shoulder. The MMA and CO yield were in the range of 87.98-93.54% and 6.46-12.02%, respectively. High MMA yield may be obtained from the pyrolysis of micron-sized PMMA waste in inert atmosphere by appropriately increasing the heating rate adopted in the reactors in the practical applications.
人们高度关注通过热解处理传统尺寸的聚甲基丙烯酸甲酯（PMMA）废料以回收甲基丙烯酸甲酯（MMA）。然而，人们对微尺寸 PMMA 废料的热解行为关注较少，而这可能与传统尺寸 PMMA 废料的热解行为有所不同。本研究采用热重分析和傅里叶变换红外分析，在惰性气氛中研究了微尺寸 PMMA 废料的热解动力学和挥发产物。采用全局优化算法 Shuffled Complex Evolution（SCE）对动力学参数进行了同时优化。结果表明，在 MLR 随温度的变化中出现了一个肩峰和一个峰值。肩峰和峰值处的 MLR 值、平均 MLR 值均随升温速率的增加而增加。SCE 优化的动力学参数可以很好地再现实验热重数据。通过 SCE 优化得到的活化能和指前因子自然对数的值分别在 235.95-248.61 kJ/mol 和 16.96-28.76 min 的范围内。本研究中微尺寸 PMMA 废料热解的活化能值大于之前研究中传统尺寸 PMMA 热解的活化能值。MMA 和 CO 是微尺寸 PMMA 废料热解生成的主要挥发性产物。在峰值处生成的挥发性产物产率远大于在肩峰处生成的产物产率。MMA 和 CO 的产率分别在 87.98-93.54%和 6.46-12.02%的范围内。在实际应用中，通过适当提高反应器中的升温速率，可以从惰性气氛中微尺寸 PMMA 废料的热解中获得较高的 MMA 产率。
