Pyrolysis characteristics and kinetics of municipal solid wastes

The large variety in municipal solid waste (MSW) composition and difference s in thermal degradation behaviour of MSW components makes modelling, desig n and operation of thermal conversion systems a challenge. The pyrolysis ch aracteristics of 11 different components, representing the dry cellulosic f raction and plastics of MSW, have been investigated. The aim of this study is to obtain detailed information on the pyrolysis characteristics and chem ical kinetics of the most important components in MSW. A thermogravimetric analysis including determination of kinetic parameters are performed at a c onstant heating rate of 10 degreesC/min in an inert atmosphere. The cellulo sic fraction of MSW was modelled by three independent parallel reactions de scribing the degradation of hemicellulose, cellulose and lignin. The plasti cs polystyrene, polypropylene, low-density polyethylene and high-density po lyethylene were all modelled as single reactions describing the degradation of hydrocarbon polymers. The degradation of PVC was modelled with three pa rallel reactions describing the release of benzene during dehydrochlorinati on, dehydrochlorination reaction and degradation of remaining hydrocarbons. Possible interactions between different paper and plastic components in mi xtures were also investigated. It was found that the reactivity of cellulos ic matter was increased in a mixture with PVC. (C) 2001 Elsevier Science Lt d. All rights reserved.