TY - JOUR
T1 - Kinetics of steam gasification of nascent char from rapid pyrolysis of a Victorian brown coal
AU - Bayarsaikhan, Bazardorj
AU - Hayashi, Jun Ichiro
AU - Shimada, Taihei
AU - Sathe, Chirag
AU - Li, Chun Zhu
AU - Tsutsumi, Atsushi
AU - Chiba, Tadatoshi
N1 - Funding Information:
The authors gratefully acknowledge the financial support provided by the New Energy and Industrial Technology Development Organization (NEDO), Japan, and the Japan Society for Promotion of Science (JSPS). The authors also gratefully thank Dr. Shohei Takeda for useful discussion on the kinetics of coal char gasification. Bazardorj Bayarsaikhan expresses personal gratitude to the Ministry of Education, Culture, Sports, Science and Technology of Japan for the scholarship provided during his participation in this research work.
PY - 2005/9
Y1 - 2005/9
N2 - Steam gasification of nascent char from rapid or slow pyrolysis of a Victorian brown coal was performed at 1073-1173 K in a novel drop-tube/ fixed-bed reactor, in which steam-containing gas was forced to pass through an extremely thin bed of nascent char particles at sufficiently high velocity and large flux. The nascent char underwent parallel reactions consisting of non-catalytic gasification and catalytic one. The non-catalytic gasification followed first-order kinetics with respect to the fraction of unconverted carbon, and the rate constant was hardly influenced by operating variables such as heating rate for the pyrolysis, total pressure and even period of isothermal heating between the pyrolysis and gasification. The overall activity of inherent catalysts, alkali and alkaline earth metallic species, diminished due to volatilization and intra-particle deactivation, both of which were induced by the gasification. As a result, the catalytic gasification took place within a limited range of the char conversion up to 60-80%. The initial catalyst activity and the kinetics of activity loss largely depended on the operating variables as above and also partial pressure of steam.
AB - Steam gasification of nascent char from rapid or slow pyrolysis of a Victorian brown coal was performed at 1073-1173 K in a novel drop-tube/ fixed-bed reactor, in which steam-containing gas was forced to pass through an extremely thin bed of nascent char particles at sufficiently high velocity and large flux. The nascent char underwent parallel reactions consisting of non-catalytic gasification and catalytic one. The non-catalytic gasification followed first-order kinetics with respect to the fraction of unconverted carbon, and the rate constant was hardly influenced by operating variables such as heating rate for the pyrolysis, total pressure and even period of isothermal heating between the pyrolysis and gasification. The overall activity of inherent catalysts, alkali and alkaline earth metallic species, diminished due to volatilization and intra-particle deactivation, both of which were induced by the gasification. As a result, the catalytic gasification took place within a limited range of the char conversion up to 60-80%. The initial catalyst activity and the kinetics of activity loss largely depended on the operating variables as above and also partial pressure of steam.
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U2 - 10.1016/j.fuel.2005.02.008
DO - 10.1016/j.fuel.2005.02.008
M3 - Article
AN - SCOPUS:18844382147
VL - 84
SP - 1612
EP - 1621
JO - Fuel
JF - Fuel
SN - 0016-2361
IS - 12-13
ER -