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Conflict of Interest: In relation to this article, we declare that there is no conflict of interest.

Publication history: Received November 26, 2007
Accepted January 14, 2009

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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CO2 gasification of Thai coal chars: Kinetics and reactivity studies

Supaporn Sawettaporn¹ Kunchana Bunyakiat^{1 2†} Boonyarach Kitiyanan^{2 3}

¹Fuels Research Center, Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Thailand ²Centers of Excellence for Petroleum, Petrochemicals, and Advanced Materials, Chulalongkorn University, Thailand ³The Petroleum and Petrochemical College, Chulalongkorn University, Thailand

Kunchana.b@chula.ac.th

Korean Journal of Chemical Engineering, July 2009, 26(4), 1009-1015(7), 10.1007/s11814-009-0168-9

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Abstract

Abstract.Two sized fractions (<75 μm and 150-250 μm) of Ban Pu lignite A and Lampang subbituminous B coals were pyrolyzed in a drop tube fixed bed reactor under nitrogen atmosphere at 500-900 ℃. Gasification of coal chars with excess carbon dioxide was then performed at 900-1,100 ℃. The result was analyzed in terms of reactivity index, reaction rate and activation energy. It was found that chars at lower pyrolysis temperature had highest carbon conversion, and for chars of the same sized fraction and at the same pyrolysis temperature, reactivity indices increased with gasification temperature. The lower rank Ban Pu lignite A had higher Rs values than higher rank Lampang subbituminous B coals. Smaller chars from both coals had higher Rs values, due to the higher ash content. At present, it can be concluded that, within the gasification temperature range studied, gasification rates of chars obtained at various pyrolysis temperatures showed a linear correlation with temperature. However, additional experiment is needed to verify the correlation.

Keywords

Coal Chars Reactivity Kinetics Gasification

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