TY - JOUR
T1 - Effect of SiO2 on loss of catalysis of inherent metallic species in CO2 gasification of coke from lignite
AU - Choi, Cheolyong
AU - Ashik, U. P.M.
AU - Kudo, Shinji
AU - Uebo, Kazuya
AU - Norinaga, Koyo
AU - Hayashi, Jun ichiro
N1 - Funding Information:
A part of this work was financially supported by the Japan Society for the Promotion of Science ( JSPS ) for Grant-in-Aid for Scientific Research A (Grant 17H01340 ). The authors are grateful to Cooperative Research Program of Network Joint Research Center for Materials and Devices that has been supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. Cheolyong Choi acknowledges the Kyushu University Program for Leading Graduate Schools: Global Strategy for Green Asia for his financial support.
Publisher Copyright:
© 2019
PY - 2019/4
Y1 - 2019/4
N2 - Inherent metallic species retained by coal char or coke, such as Na and Ca, behave as catalysts in gasification. The char/coke normally contains inherent SiO2, which can react with the inherent catalysts to form silicates, resulting in catalyst deactivation over the range of pyrolysis, carbonization and gasification, and thereby reducing the char/coke reactivity. The present authors simulated the inherent catalyst deactivation experimentally by blending a Victorian lignite with SiO2, briquetting the SiO2/lignite blend, carbonizing the briquette, and then gasifying the coke with CO2. The kinetic analysis of the gasification employed a comprehensive model, which assumed progress in parallel of non-catalytic and catalytic gasification. The model quantitatively described the measured kinetics of the coke gasification with different SiO2 contents over a range of coke conversion up to 99.9%. The kinetic analysis revealed that the SiO2 deactivated substantial and entire portions of the most active catalyst and its precursor, respectively, before the gasification (i.e., during the carbonization). The catalyst deactivation also occurred during the gasification, but mainly following a self-deactivation mechanism that involved no silicates formation.
AB - Inherent metallic species retained by coal char or coke, such as Na and Ca, behave as catalysts in gasification. The char/coke normally contains inherent SiO2, which can react with the inherent catalysts to form silicates, resulting in catalyst deactivation over the range of pyrolysis, carbonization and gasification, and thereby reducing the char/coke reactivity. The present authors simulated the inherent catalyst deactivation experimentally by blending a Victorian lignite with SiO2, briquetting the SiO2/lignite blend, carbonizing the briquette, and then gasifying the coke with CO2. The kinetic analysis of the gasification employed a comprehensive model, which assumed progress in parallel of non-catalytic and catalytic gasification. The model quantitatively described the measured kinetics of the coke gasification with different SiO2 contents over a range of coke conversion up to 99.9%. The kinetic analysis revealed that the SiO2 deactivated substantial and entire portions of the most active catalyst and its precursor, respectively, before the gasification (i.e., during the carbonization). The catalyst deactivation also occurred during the gasification, but mainly following a self-deactivation mechanism that involved no silicates formation.
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U2 - 10.1016/j.crcon.2018.09.002
DO - 10.1016/j.crcon.2018.09.002
M3 - Article
AN - SCOPUS:85068145096
VL - 2
SP - 13
EP - 22
JO - Carbon Resources Conversion
JF - Carbon Resources Conversion
SN - 2588-9133
IS - 1
ER -