Euler-Lagrange Modeling of Entrained Flow Gasification of Coke-Biomass Slurry Mixture
American Journal of Energy Engineering
Volume 1, Issue 4, September 2013, Pages: 43-50
Received: Sep. 25, 2013;
Published: Oct. 20, 2013
Views 3085 Downloads 235
Peter Mtui, College of Engineering and Technology, University of Dar es Salaam, P. O. Box 35131, Dar es Salaam, Tanzania
An Euler-Lagrange CFD method for co-gasification simulation of slurry mixture of pulverized petroleum coke and up to 20% biomass (wheat straw) in a pressurized entrained flow gasifier is proposed to increase the biomass contribution to green electricity generation. The gas phase is modeled as a continuum and the solid phase is modeled by a Discrete Phase Modeling (DPM) using a soft sphere approach for the particle collision dynamic. The model takes into account detailed gas phase chemistry, modeling of the pyrolysis and gasification of each individual particle, particle shrinkage, and heat and mass-transfer between the gas phase and the dispersed phase. The coke was blended with 5–20% wheat straw on mass basis. The effect of the percentage of biomass blended with coke on the flow field, gas and temperature distribution, syngas composition and particles trajectories are presented. Most important result is the quality and quantity of syngas produced when blended up to 20% biomass is similar to that of coke gasification. Additional observation is that the reactivity of coke was greatly improved by the presence of biomass. The overall conclusion of this his study is that co-gasification is possible provided that operation is properly adapted.
Euler-Lagrange Modeling of Entrained Flow Gasification of Coke-Biomass Slurry Mixture, American Journal of Energy Engineering.
Vol. 1, No. 4,
2013, pp. 43-50.
Radmanesh, R, J. Chaouki, and C. Guy. Biomass gasification in a bubbling fluidized bed reactor: Experiments and modeling. AIChE Journal, 52(12):4258–4272, 2006.
Zhou H, G. Flamant, and D. Gauthier. DEM-LES of coal combustion in a bubbling fluidized bed. Part I: Gas-particle turbulent flow structure. Chemical Engineering Science, 59:4193–4203, 2004.
Rong D and M. Horio. DEM simulation of char combustion in a fluidized bed. In 3rd Int. Conf. on CFD in the Minerals and Process Industries, pages 469–474. CSIRO, Melbourne, Australia, 1999.
Lathouwers D. and J. Bellan. Modelling of dense gas-solid reactive mixtures applied to biomass pyrolysis in a fluidized bed. Int. J. of Multiphase Flow, 27:2155–2187, 2001.
Agrawal K, Loezos P. N. , Syamlal, M and S. Sundaresan: The role of meso-scale structures in rapid gas-solid flows. J. of Fluid Mechanics, 445:151–185, 2001.
Bockelie M, Denison M, Chen Z. Linjewile T, Senior C and A. Sarofim: Modeling of Entrained Flow Gasifiers, Gasification Technology Conference 2002, October 27-29, 2002, San Francisco, CA USA
Furimsky, E., Gasification of oil sand coke: Review. Fuel Processing Technology, 1998. 56(3): p. 263-290.
Chunggen Yin, Soren Knudsen, Lasse Rosendahl and Soren Lovmand: Modeling of Pulverized Coal Biomass Co-firing Swirling-Stabilized Burner and Experimental Validation Proceedinds of the International Conference on Power Engineering-09 (ICOPE-9) 16-20, 2009, Kobe, Japan
Fluent 12 User Guide Copyright @2009 by ANSYS, Inc.
Ferziger, J. and M. Peric. Computational Methods for Fluids Dynamics. Springer Verlag, 1999.
Chung T. J., Computational Fluid Dynamics. Cambridge University Press, 2002.
Badzioch, S., and Hawksley, P. G. W. (1970). Kinetics of Thermal Decomposition of Pulverized Coal Particles, Ind. Eng. Chem. Process Des. Develop. , 9(4), 521-530.
Baum, M. M., and Street, P. J. (1971). Predicting the Combustion Behaviour of Coal Particles. Combustion Science and Technology, 3(5), 231-243.