PET和关中麦秆共热解特性及其动力学研究

利用TG-FTIR技术研究陕西关中地区小麦秸秆（麦秆）、聚对苯二甲酸乙二醇酯（PET）及其两者混合物麦秆-PET（质量比1：1）在20 K/min的升温速率下的热解行为、主要热解产物、协同效应和动力学。研究结果表明：PET热解初始温度为375℃，最大热失重速率处的温度为454.9℃，失重率为62.87%，其热解残余质量为19.42%；麦秆-PET的热解DTG曲线表现为麦秆和PET主失重峰（339.9和444℃）的叠加，且混合试样在两个强峰处的失重率分别为22.9%和73.9%，最终热解残余质量为23.52%；PET和麦秆共热解过程中会出现两个协同效应（339.9和444℃），这使得共热解产物中的CO、CH₄以及芳香族、酸类、酮类、醛类、醇类、烷烃、酚类和醚类等轻质焦油组分含量高于麦秆和PET单独热解，共热解提高了热解产物的热值，改善了热解产物组成，提升了热解产物的稳定性和燃料品质；采用Coats-Redfern积分法计算得到PET在主热解区的表观活化能为355.48 kJ/mol，远高于麦秆的表观活化能（86.5 kJ/mol），麦秆-PET在低温区（258~363℃）的表观活化能为53.6 kJ/mol，在高温区（393~463℃）的表观活化能为81.6 kJ/mol。

Co-pyrolysis Characteristics and Kinetics of PET and Wheat Straw

Pyrolytic behaviors, main pyrolytic products, synergistic effect and kinetics of Guanzhong wheat straw, polyethylene Terephthalate(PET) sample and its blends(mass ratio 1:1) were investigated by TG-FTIR system at heating rate of 20 K/min. The results demonstrated that the initial pyrolysis temperature of PET sample was 375℃ and the maximum weight loss rate(62.87%) occured at the temperature of 454.9℃ and the residual amount was about 19.42%.The weight loss rates of the mixture were 22.9% and 73.9% at the two weight loss peak(339.9 and 444℃), respectively. At that time, the final prolysis residual amount was about 23.52%. There were two synergistic effects(339.9 and 444℃) in the process of co-pyrolysis which enhanced the amount of pyrolysis products of CO, CH₄, aromatics, acids, ketones, aldehydes, alcohols, alkanes, phenols and ethers. The heating value and fuel quality of the raw material were enhanced a lot by the co-pyrolysis process. The apparent activation energy of PET in higher than that of wheat straw(86.5 kJ/mol). And the apparent activation energies of the mixture calculated by Coats-Redfern method were 53.6 kJ/mol at low pyrolysis temperature region(258-363℃) and 81.6 kJ/mol at the high pyrolysis temperature region(393-463℃).