CFD Modeling of Devolatilization and Combustion of Shredded Tires and Pine Wood in Rotary Cement Kilns
American Journal of Energy Engineering
Volume 1, Issue 5, November 2013, Pages: 51-55
Received: Sep. 25, 2013;
Published: Nov. 10, 2013
Views 3241 Downloads 250
Peter Mtui, College of Engineering and Technology, University of Dar es Salaam, ar es Salaam, Tanzania
Computational fluid dynamics (CFD) has been used to study the devolatilization and combustion of large particles of shredded scrap tire “rubber” and pulverized pine wood “biomass” in a rotary cement kilns. The CFD model constitutes of modeling the hydrodynamics within the rotary kiln, heat transfer, devolatilization and co-combustion of rubber and biomass blends. Equivalent particle diameters of 1 mm and 2 mm for biomass and rubber, respectively, were used to simulate the process conditions and co-combustion in cement rotary kilns. The ratios of biomass substitution were varied from 5% to 20% on mass basis. The effect of the percentage of biomass content on the temperature distribution and devolatilization rate as well as wall heat transfer rate are presented. Results indicate that up to 20% biomass blend provides improved combustion characteristics compared with combustion of scrap tire alone. Further, the devolatilization rate was found to improve remarkably when scrap tire is blended with biomass. Most importantly, the biomass blend was found to increase the flame spreading and penetration, consequently improving the wall heat transfer rate, therefore providing favorable conditions for heat transfer to the cement clinker. The present study provides additional knowledge for future investigations on the use of biomass residues and some industrial wastes as alternative fuels for rotary cement kilns. That is, the use of alternative fuels in rotary cement kilns has a potential for economic improvement and environmental sustainability.
CFD Modeling of Devolatilization and Combustion of Shredded Tires and Pine Wood in Rotary Cement Kilns, American Journal of Energy Engineering.
Vol. 1, No. 5,
2013, pp. 51-55.
BP Statistical Review of World Energy; June 2009, http://www.bp.com.
Cembureau,: Alternative Fuels in Cement Manufacture; 1997, http://www.cembureau.be
R.C. Poller, Reclamation of waste plastics and rubber recovery of materials and energy, J. Chem. Tech. Biotechnol. 30_1980.152–160.
G. Genon and E. Brizio, "Perspectives and limits for cement kilns as a destination for RDF," Waste Management, Vol. 28, no. 11, pp. 2375–2385, Nov. 2008.
U. Kaantee, R. Zevenhoven, R. Backman and M. Hupa, "Cement manufacturing using alternative fuels and the advantages of process modelling," Fuel Processing Technology, Vol. 85, no. 4, pp. 293-301, Mar. 2004.
Conesa J.A., Font R., Marcilla R. Mass spectrometry validation of a kinetic model for the thermal decomposition of tyre wastes. Journal of Analytical and Applied Pyrolysis 43; pp. 83-96; 1997.
Yang J., Tanguy P. A., Roy C. Heat transfer, mass transfer and kinetics study of the vacuum pyrolysis of a large used tire particle. Chemical Engineering Science 50; pp. 1909-1922; 1995.
Larsen, M. B.; Schultz, L.; Glarborg, P.; Skaarup-Jensen, L.; Dam-Johansen, K.; Frandsen, F.; Henriksen, U. Fuel 2006, 85, 1335−1345.
Chinyama, M. P. M; Lockwood, F. C. J. Energy Inst. 2007, 80 (3), 162−167
Atal, A.; Levendis, Y. A. Fuel 1995, 74 (11), 1570−1581
de Diego L. F., F. García-Labiano, A. Abad, P. Gayán, J. Adánez Coupled drying and devolatilization of non-spherical wet pine wood particles in fluidized beds. Journal of Analytical and Applied Pyrolysis 65 (2002) 173–184
Di Blasi, C.; Branca, C. Energy Fuels 2003, 17, 247−254
C. Di Blasi, Modeling chemical and physical processes of wood and biomass pyrolysis, Progress in Energy and Combustion Science 34 (2008) 47–90
J.E. White, W.J. Catallo, B.L. Legendre, Biomass pyrolysis kinetics: a comparative critical review with relevant agricultural residue case studies, Journal of Analytical and Applied Pyrolysis 91 (2011) 1–33.
M. Juma, Z. Koreňová, J. Marks, J. Annus, L. Jelemensky. Pyrolysis and Combustion of Scrap Tires Petroleum & Coal 48 (1), 15-26, 2006
H. Kobayashi, J. B. Howard, and A. F. Saro Coal Devolatilization at High Temperatures. In 16th Symp. (Int'l.) on Combustion. The Combustion Institute, 1976
Braum M. M. and P. J. Street. Predicting the Combustion Behaviour of Coal Particles. Combustion Science and Technology, 3(5), 231-243. (1971)
Field M. A. Rate of Combustion of Size-Graded Fractions of Char from a Low Rank Coal between 1200K and 2000K. Combustion and Flame, 13, 237-252. (1969)
Elaine S. Oran and Jay P. Boris Numerical Simulation of Reactive Flow, Cambridge University Press, Second Edition, Second edition (2001)
Fluent 12 User Guide Copyright @2009 by ANSYS, Inc.