Co-Gasification of Mesquite and Coal Blend in an Updraft Fixed Bed Gasifier

Wei Chen, Siva Sankar Thanapal, Kalyan Annamalai, Robert James Ansley, Mustafa Mirik

Department of Mechanical Engineering, Texas A&M University, College Station, USA.
Texas AgriLife Research, Vernon, USA.

DOI: 10.4236/jsbs.2013.33032                

Abstract

In order to reduce the emission of NO_x, SO_x, and CO₂ and mitigate the dependence on the fossil fuel, the use of renewable energy, especially the biomass energy, has been explored. Since most biomass fuels are hard to grind to the very fine size, gasification is the preferred technology of energy conversion. Updraft fixed bed gasification using partial oxidation process is adopted where air less than the stoichiometric quantity is admitted to oxidize the char to CO. The temperature profile within the bed reveals a characteristic temperature peak. The results reveal a correlation between the higher heating value (HHV) of producer gas and the peak gasification temperature (T_peak). Coal with higher char content (~45%) is blended with biomass of low char content (~20%) in order to produce high quality gas. In this study, the Texas-based mesquite fuel was blended with Wyoming Power River Basin (PRB) coal with mass ratios of 100:0, 90:10, and 80:20 and fired downward into the gasifier. It was found that at a given mesquite to the coal mass ratio, the peak gasification temperature decreased with the increase in ER. With the increase of the coal ratio in the mesquite: coal blend and the peak temperature increased significantly; more combustible gases such as CO, CH₄ were generated at the end of product gas, and the HHV of the product gas increased by 10%-20%.  

Keywords

Gasification; Bioenergy; Coal; Heating Value; Sustainability

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	G. Morris, “The Value of the Benefits of US Biomass Power,” Subscontractor Report for DOE, 1999.
[2]	R. N. Brian Murray, M. Ross, T. Holloway and S. Patil, “Biomass Energy Consumption in the Forest Products Industry,” Final Report for US Department of Energy, 2006.
[3]	G. gordillo, “Fixed Bed Counter Current Low Temperature Gasification of Dairy Biomass and Coal-Dairy Biomass Blends Using Air-Steam as Oxidizer,” PhD Dissertation, Mechanical Engineering, Texas A&M University, College Station, 2009.
[4]	W. Chen, K. Annamalai, J. Ansley and M. Mirik, “Updraft Fixed Bed Gasification of Mesquite and Juniper Wood Samples,” Energy, Vol. 41, No. 1, 2012, pp. 454-461. doi:10.1016/j.energy.2012.02.052
[5]	K. Kumabe, T. Hanaoka, S. Fujimoto, T. Minowa and K. Sakanishi, “Co-Gasification of Woody Biomass and Coal with Air and Steam,” Fuel, Vol. 86, No. 5-6, 2007, pp. 684-689. doi:10.1016/j.fuel.2006.08.026
[6]	Y. G. Pan, E. Velo, X. Roca, J. J. Manya and L. Puigjaner, “Fluidized-Bed Co-Gasification of Residual Biomass/ Poor Coal Blends for Fuel Gas Production,” Fuel, Vol. 79, No. 11, 2000, pp. 1317-1326. doi:10.1016/S0016-2361(99)00258-6
[7]	X. L. W. Yan, “Effect of Equivalence Ratio on Co-Gasification of Pine Sawdust and Coal,” Kezaisheng Nengyuan/Renewable Energy Resources, Vol. 27, No. 5, 2009, pp. 42-47.
[8]	W. Chen, K. Annamalai, R. J. Ansley and M. Mirik, “Updraft Fixed Bed Gasification of Mesquite and Juniper Wood Samples,” Energy, Vol. 41, No. 1, 2012, pp. 454-461. doi:10.1016/j.energy.2012.02.052
[9]	G. Ariza, “Fixed Bed Counter Current Low Temperature Gasification of Dairy Biomass and Coal-Dairy Biomass blends Using Air-Steam,” PhD Dissertation, Mechanical Engineering, Texas A&M University, College Station, 2009.
[10]	http://blogs.princeton.edu/chm333/f2006/biomass/comparison/sustainability/
[11]	http://en.wikipedia.org/wiki/Mesquite
[12]	R. J. Ansley, M. Mirik and M. J. Castellano, “Structural Biomass Partitioning in Regrowth and Undisturbed Mesquite (Prosopis glandulosa): Implications for Bioenergy Uses,” Global Change Biology Bioenergy, Vol. 2, No. 1, 2010, pp. 26-36. doi:10.1111/j.1757-1707.2010.01036.x
[13]	http://uts.cc.utexas.edu/~gilbert/mesquite/nitrofixation.html
[14]	P. Srinivasan and M. Y. Liu, “Comparative Potential Therapeutic Effect of Sesame Oil and Peanut Oil against Acute Monocrotaline (Crotalaria) Poisoning in a Rat Model,” Journal of Veterinary Internal Medicine, Vol. 26, 2012, pp. 491-499. doi:10.1111/j.1939-1676.2012.00909.x
[15]	W. Xu, Y. Li and A. B. Carraway, “Estimation of Woody Biomass Availability for Energy in Texas,” Texas Forest Service Report, College Station, 2008.
[16]	G. Gordillo and K. Annamalai, “Adiabatic Fixed Bed Gasification of Dairy Biomass with Air and Steam,” Fuel, Vol. 89, No. 2, 2010, pp. 384-391. doi:10.1016/j.fuel.2009.07.018
[17]	W. Chen, “Fixed Bed Counter Current Gasification of Mesquite and Juniper Biomass Using Air-Steam as Oxidizer,” PhD Dissertation, Mechanical Engineering, Texas A&M University, College Station, 2012.
[18]	K. Annamalai and I. K. Puri, “Combustion Science and Engineering,” Taylor & Francis Group, London, 2007.