Study On Co-pyrolysis Of Low Metamorphic Coal And Plastic With Microwave

Aiming at changing the present situation of domestic "deficient oil, lean gas, richcoal" energy structure and solving the increasingly serious white pollution,co-pyrolysis of low metamorphic coal and plastic generating solid, liquid and gasproducts will be a new technology which has a wide application foreground, which issignificantly important to the reasonable utilization of low metamorphic coal resourcesand ease up the increasingly serious white pollution.In this paper, the characteristic of microwave-assisted co-pyrolysis of the lowmetamorphic coal and plastic was investigated, which was focused on the effects ofmicrowave powers, proportion of added plastic, particle sizes of raw coal, pyrolysisreaction time, and condensing temperature etc. on the co-pyrolysis process andproducts based on the dynamics analysis of microwave-assisted pyrolysis. Whiledetermined the optimal technological process and technical parameters.Kinetic studies suggested that the pyrolysis process perfectly met the model offirst-order decomposition reaction under the experimental conditions. During theconventional pyrolysis, the values of E, namely the apparent activation energy, of SunJiacha coal （SJC）, polypropylene plastics （PP） and the mixture of the former two were29.3kJ·mol^-1,234.7kJ·mol^-1and133.3kJ·mol^-1separately.During the co-pyrolysis of the low metamorphic coal and plastic, the more plasticwas added, the higher yields of tar and gas would be gained. When the proportion ofadded plastic increased to10%, the content of tar and gas would increase to17%and19%respectively and the light oil would increase to70.9%, while the intermediate oilwoule decrease to20.8%, causing the convertion to the light fraction. Partical sizes silightly affected the co-pyrolysis products. Condensing temperature could greatlyaffect the yields of tar and gas, but not the solid coke. Tar yield increased and gas yielddecreased when the condensing temperature became lower. When the condensingtemperature decreased to-10℃, the tar yield would increase to16.8%, in which thecontent of medium oil would decrease to23%and the heavy oil would increase to51.4%. The higher microwave power is, the shorter time the material takes to get to thehighest reaction temperature. When the microwave power decreased to480W, thecontents of CO, H₂and CH₄were13.1%,35.6%and21.9%respectively, indicatingthat the appropriate microwave power is greatly important to the pyrolysis products.