Kinetic and volatile products study of micron-sized PMMA waste pyrolysis using thermogravimetry and Fourier transform infrared analysis

Abstract

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−1, 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 CO2 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 CO2 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.