International Science Index


16863

Modeling Moisture and Density Behaviors of Wood in Biomass Torrefaction Environments

Abstract:

Worldwide interests for the renewable energy are increasing due to environmental and climate changes from traditional petroleum related energy sources. To account for these social needs, ligneous biomass energy is considered as one of the environmentally friend energy solutions. The wood torrefaction process is a feasible method to improve the properties of the biomass fuel and makes the wood have low moisture, lower smoke emission and increased heating value. In this work, therefore, the moisture evaporation model which largely affects energy efficiency of ligneous biomass through moisture contents and heating value relative to its weight is studied with numerical modeling approach by analyzing the effects of torrefaction furnace temperature. The results show that the temperature and moisture fraction of wood decrease by increasing the furnace temperature. When the torrefaction temperature is lower than 423K, there were little changes of the moisture fraction in the wood. Also, it can be found that charcoal is produced more slowly when the torrefaction temperature is lower than 573K.

References:
[1] Blasi, C., "Modeling and Simulation of Combustion Processes of Charring and Non-charring Solid Fules," Progress in Energy and Combustion Science, Vol. 19, No. 5, pp. 71-104, 1993.
[2] Blasi, C., "Heat, Momentum and Mass Transport through a Shrinking Biomass Particle exposed to Thermal Radiation," Chemical Engineering Science, Vol. 51, No. 7, pp. 1121-1132, 1996.
[3] Lee, C. K., Chaiken, R. F., and Singer, J. M., “Charring pyrolysis of wood in fires by laser simulation,” Symposium on Combustion, Vol. 16, No. 1, pp. 1459-1470, 1976.
[4] Morel, J. I., Amundson, N. R., and Park, S. K., “Dynamics of a Single Particle during Char Gasification,” Chemical Engineering Science, Vol. 45, No. 2, pp. 387-401, 1990.
[5] Chan, W. C. R., Kelbon, M., and Krieger, B. B., "Modelling and Experimental Verification of Physical and Chemical Processes during Pyrolysis of a Large Biomass Particle," Fuel, Vol. 64, No. 11, pp. 1505-1513, 1985.
[6] Prins, M. J., Ptasinski, K. J., and Janssen, F. J. J. G., "Torrefaction of Wood. Part 1: Weight Loss Kinetics," Journal of Analytical and Applied Pyrolysis, Vol. 77, No. 1, pp. 28-34, 2006.
[7] Turner, I., Rousset, P., Rémond, R., and Perré, P., "An Experimental and Theoretical Investigation of the Thermal Treatment of Wood (FagusSylvatica L.) in the Range 200-260°C," International Journal of Heat and Mass Transfer, Vol. 53, No. 4, pp. 715-725, 2010.
[8] Felfli, F. F., Soler, P. B., and Rocha, J. D., "MathmaticalModelling of Wood and Briquettes Torrefaction," Proceedings of the 5th Encontro de Energia no Meio Rural, Campinas, Spain, October 19-21, 2004.
[9] Thurner, F. and Mann, U., "Kinetic Investigation of Wood Pyrolysis," Industrial & Engineering Chemistry Process Design and Development, Vol. 20, No. 3, pp. 482-488, 1981.