LINEAR PYROLYSIS OF CELLULOSIC AND PLASTIC WASTE

Numerical simulations of the linear pyrolysis of cellulose and polyeth ylene are presented. Depolymerization and melting are followed, in the first case, by a competition between the formation of tar vapors and char (with some gas), and in the second case, by complete devolatiliza tion. Surface regression, property variation, heat convection and cond uction through the virgin solid and the molten layer are properly take n into account. The dependence of process dynamics, regression rate, s urface temperature and thickness of the reaction zone on the heating c onditions is simulated. The results are important in order to clarify the role of internal and external heat transfer mechanisms and the dif ferences between the two fuels, with a view of energy recovery through MSW pyrolysis. (C) 1997 Elsevier Science B.V.