Operating parameters of autothermal pyrolosis of plastic waste in a fluidized bed

Abstract

In this study, polyethylene was pyrolysed in the fluidized-bed pyrolysis system in a limited oxygen supply. Thus, the heat to pyrolyse the polyethylene was made available by partial incineration of the polyethylene, which can be referred to as autothermal pyrolysis. The fluidized bed was selected as the reactor owing to its high capacity, homogeneity and low tar content. Experimental parameters evaluated included the effect of: (1) the pyrolysis temperatures; (2) the air factors; and (3) the catalyst on the liquid hydrocarbon (gasoline, die sel, fuel oil, residual) formation, and B. T. X. (benzene, tolu ene, xylene) concentration in gasoline. Moreover, the pri mary composition in gasoline was analyzed. The results indi cated that it is practical to recover oil from plastic waste using the autothermal pyrolysis system.

Keywords

Plastic autothermal pyrolysis fluidized bed

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References

Agrawal, R.K. (1988) Kinetic of reactions involved in pyrolysis of cellulose I. Three reaction model. The Canadian Journal of Chemical Engineering 66, 403-412.

Cheng, Y.Y. (1992) Thermal oxidation of polypropylene containing hindered piperidine compounds. Polymer Degradation and Stability 37, 11-17

Dodson, B. & McNeil, I.C. (1976) Degradation of polymer mixture. VI Blends of poly(vinylchloride) with polystyrene. Journal of Applied Polymer Science 20, 353-364.

Dung, N.V. (1990) Yield and chemical characteristics of Products from Fluidized Bed Steam Retorting of Condor and Satuart Oil Shales: Effect of Pyrolysis Temperature. Fuel 69, 200-209.

Guyot, A. (1986) Recent developments in the thermal degradation of polystyrene - A review. Polymer Degradation and Stability 15, 219-235.

Hjertberg, T. & Sorvik, E.M. (1978) On the influence of HCI on the thermal degradation of poly (vinylchloride). Journal of Applied Polymer Science 22, 2415-2426.

Kansa, E.J. (1977) Mathematical model of wood pyrolysis including internal forced convection. Combustion and Flame 29, 311-324.

Kathekakis, I.E. , Lm, L.S. , Bartle, K.D. & Kandiyoti, R. (1990) Effect of Freeboard Residence Time on the Molecular Mass Distributions of Fluidized Bed Pyrolysis Tars. Fuel 69, 172-176.

Levenspiel, O. (1972) Chemical Reaction Engineering (second edition). New York, NY, USA: John Wiley and Sons.

10.

Littlewood, K. (1977) Gasification Theory and Application. London, UK Pergamon Press.

11.

Maloney, D.J. & Jenkins, D.J. (1984) Couple heat and mass transport and chemical kinetic rate limitations during coal rapid pyrolysis. Twentieth Symposium on Combustion The Combustion Institute, Pittsburgh, PA, USA, pp. 1435-1443

12.

Nelson, W. L. (1987) Petroleum Refinery Engineering. New York, NY, USA. McGraw-Hill.

13.

Nunn, T.R. , Howard, J.B. , Lomgwell, J.P. & Peter, B.A. (1985) Product compositions and kinetics in the rapid pyrolysis of sweet gum hardwood. Industry Engineering Chemistry Process Design & Development 24, 836-844.

14.

Roy, C. , Labrecque, B. & de Canmia, V (1990) Recycling of scrap tires to oil and carbon black by vacuum pyrolysis. Resources, Conservation and Recycling 4, 203-213.

15.

Schoeters, J. (1983) The Fluidized Bed Gasification of Charcoal. Ph. D. Thesis. Vrije Unversity, Brussels , Belgium.

16.

Serio, M.A. , Hamblen, D.G. , Markham, J.R. & Solomon, P.R. (1987) Kinetics and volatile product evolution in coal pyrolysis: experiment and theory. Energy Fuel 1, 138.

17.

Takarada, T. , Tonishi, T. , Takezawa, H. & Kato, K. (1992) Pyrolsis of yallourn coal in a powder-particle fluidized bed. Fuel 71, 1087-1092.

18.

Wall, L.A. (1972) Pyrolysis of polymer. National bureau of standards special publication 357, the mechanisms of pyrolysis, oxidation, and burning of organic materials. Proceedings of The 4th Materials Research Symposium. October 26-19, 1970, Gaithersburg, MD., USA.

19.

Wey, M.Y. & Chang, C.L. (1995) Kinetic study of polymer material incineration . Polymer Degradation and Stability 48, 25-33.

20.

Wilcox, C.F. (1987) Experimental Organic Chemistry. New York, NY, USA. Macmillan. pp. 17-54.

21.

Williams, P.T. , Besler, S. & Taylor, D.T. (1990) The pyrolysis of scrap automotive tyres: the influence of temperature and heating rate on product composition. Fuel 69, 1474-1482.