A Kinetic Model for a Stratified Downdraft Gasifier

A Kinetic Model for a Stratified Downdraft Gasifier

S. PedrazziG. Allesina P. Tartarini  

Dipartimento di Ingegneria Enzo Ferrari, Università degli studi di Modena e Reggio Emilia Via Vignolese, 905 – 41125 Modena, Italia.

Corresponding Author Email: 
30 June 2012
| Citation



A model for a stratified downdraft gasifier has been developed. It has been adapted from two different models from literature with appropriate modifications and improvements. The new “interacting” model is able to predict the syngas composition, input and output flow rates and the gasifier cold efficiency under different working condition and with different biomass input. It works assuming a constant biomass consumption. The results of the model has been compared to experimental data taken from a downdraft gasifier power plant system with nominal power output of 200 kWel. The plant has been set at 160 kWel in order to avoid system instabilities related to high power runs.

1. Introduction
2. Mathematical Modeling
3. Simulation And Results
4. Conclusion

The authors gratefully acknowledge the project support from Regione Emilia Romagna and En.Cor. S.r.l.


[1] T.B. Reed, A. Das, Handbook of Biomass Downdraft Gasifier Engine Systems. U.S. Department of Energy: Solar Energy Research Institute, 1988. 

[2] FAO, Wood gas as engine fuel, Rome: Publication Division, Food and Agriculture of the United Nations, ISBN 92-5-102436-7, 1986. 

[3] G. Galeno, Modellizzazione di un micro cogeneratore basato sulla tecnologia MCFC accoppiata ad un gassificatore di biomassa, Ph.D. thesis Università degli Studi di Napoli Federico II, 2007. 

[4] A. Duvia, M. Gaia, Cogenerazione a biomassa mediante Turbogeneratori ORC Turboden: tecnologia, efficienza, esperienze pratiche ed economia. Energia prodotta dagli scarti del legno: opportunità di cogenerazione nel distretto mobile, 11 novembre 2004. 

[5] F. Martelli et al., Technical study and environmental impact of an external fired gas turbine power plant fed by solid fuel. Proc. 1st World Conference of Biomass, Sevilla 2000. 

[6] V. Naso, La macchina di Stirling. CEA, 1991. 

[7] C. Souleymane, Motori a combustione interna e turbine a gas di piccola taglia per gas di sintesi. Bachelor thesis Università degli Studi di Padova, 2011-2012. 

[8] F. Marini, Monitoraggio e valutazione delle prestazioni di un impianto di cogenerazione a cippato di legno con gassificatore e motore Stirling, Centro Cisa website: http://www.centrocisa.it/ImpiantiRealizzati/stirlingCasteldaiano.php [25/04/2012]. 

[9] M.P. Arnavat, J.C. Bruno, A. Coronas, Review and analysis of biomass gasification models, Renewable and Sustainable Energy Reviews, vol. 14 (2010), pa. 2841-2851. 

[10] T.B. Reed, M.L. Markson, A predictive model for stratified downdraft gasifier, Progress in Biomass Conversion, vol. 4 (1983), pag. 219-254. 

[11] T.B. Reed, B. Levie, A simplified model of the stratified downdraft gasifier, International Bio-Energy Directory and Handbook (1984), pag. 379-389. 

[12] T.B. Reed, B. Levie, M.L. Markson, M.S. Graboski, A mathematical model for stratified downdraft gasifier, Symposium on Mathematical Modeling of Biomass Pirolysis Phenomena, 1983. 

[13] Y. Wang, C.M. Kinoshita, Kinetic model of biomass gasification, Solar Energy, vol. 51 (1993), pag.19-25. 

[14] A.Kr. Sharma, Equilibrium modeling of global reduction reactions for a downdraft (biomass) gasifier, Energy Conversion and Management, vol. 49 (2008), pag. 832–842. 

[15] A.Kr. Sharma, Modeling and simulation of a downdraft biomass gasifier 1. Model development and validation, Energy Conversion and Management, vol. 52 (2011), pag. 1386–1396. 

[16] E.R. Huff, Effect of size, shape, density, moisture and furnace wall temperature on burning time of wood pieces. In: Fundamentals of thermochemical biomass conversion: An International conference, Estes Park, CO; 1982. 

[17] K.J. Laidler, Chemical kinetics. Harper & Row Publishers, New York; 1987. 

[18] L. Waldheim, T. Nilsson, Heating value of gases from biomass gasification. Report prepared for: IEA Bioenergy Agreement, Task 20 – Thermal Gasification of Biomass, 2001. 

[19] S.A. Channiwala, P.P Parikh, A unified correlation estimating HHV of solid, liquid and gaseous fuels, Fuel, vol. 81 (2002), pag.1051-1063. 

[20] G. Allesina, C. Cattini, S. Pedrazzi, P. Tartarini. Sperimentazione di metodi non invasisi per il monitoraggio di un impianto di gassificazione a biomasse legnose, La Termotecnica, marzo 2012. 

[21] R.C. Everson, H.W.J.P. Neomagus, H. Kasaini, D. Njapha, Reaction kinetics of pulverized coal-chars derived from inertinite-rich coal discards: Gasification with carbon dioxide and steam, Fuel, vol. 85 (2006), pag. 1076-82.