Abstract
Polyethylene is the type of waste plastic that accounts for the most significant proportion of municipal solid waste.Waste polyethylene can be valorized via pyrolysis and produce value-added oil,gas,and char.On the other hand,self-sustaining smoldering is an emerging technical means to deal with sand/soil contaminated by organic matter.The high-temperature heat generated by smoldering can be used as a heat source for pyrolyzing waste polyethylene.Therefore,this study investigates numerically the pyrolysis of waste polyethylene driven by self-sustaining smoldering.A novel 4-step lumped kinetic model is proposed for simulating the pyrolysis of waste polyethylene.The results indicate that the operating parameters can determine the pyrolysis product yields by regulating the pyrolysis temperature and the volatile residence time.Note that higher temperatures and longer residence times favor the generation of shorter-chain pyrolysis products because of the intensified volatiles'sec-ondary cracking.It can be concluded that a high interface-wall heat transfer coefficient(400 W m-2 K-1),a low PE content(0.20),a high char concentration(2.4％),and a moderate air velocity(0.040 m s-1)are beneficial to oil yield.To some extent,this study may broaden the boundaries for the application of self-sustained smoldering-driven pyrolysis.
基金项目
China National Key Research and Development Plan Project(2018YFA0702300)
National Natural Science Foundation of China(51950410590)
National Natural Science Foundation of China(52227813)
维普
万方数据