LIU Jiamin;GU Sumin;ZHANG Rong;LI Weiwei;QU Xuan;

• 1:School of Chemistry and Chemical Engineering
• 2:North University of China
• 3:State Key Laboratory of Coal Conversion
• 4:Institute of Coal Chemistry

Abstract：

The coal catalytic hydrogasification is a highly promising technology for converting coal to natural gas. It consists of coal catalytic hydropyrolysis and char catalytic hydrogasification. The char catalytic hydrogasification is the rate-controlling step of the whole process because its rate is much less than that of coal catalytic hydropyrolysis. Therefore, it is critical to establish a reasonable kinetic model of Co-Ca catalyzed char hydrogasification in pressurized fluidized bed for the technology′s future development. The variations of particle density and pore characteristics with carbon conversion were investigated during Co-Ca catalyzed char hydrogasification in a lab-scale pressurized fluidized bed. The results show that the char particle density decrease as the carbon conversion, and there is linear correlation between the total pores specific surface area and reaction rate. These phenomena confirm that the conversion of char should follow the random pore model during Co-Ca catalyzed char hydrogasification. The effects of reaction temperature, hydrogen pressure, and Co loading on the carbon conversion were researched. It is found that the reaction is controlled by dynamics in the range of 650-850 ℃. The reaction rate is dramatically increased when the temperature is over 750 ℃, and the carbon conversion increase from 16.32% to 95.32% when reaction temperature is elevated from 650 ℃ to 850 ℃. The carbon conversion is elevated to 94.11% with increasing the hydrogen partial pressure from 0.6 MPa to 2.5 MPa. Raising the Co loading from 1% to 3% resultes in the continous increase in carbon conversion, but it has little change when the Co loading is furtherly increased to 5%. The experiment data was analyzed adopting an extended random pore model with the introduction of empirical parameters c and p. The results indicate that the activation energy of coal char catalytic hydrogasification is 122.7 kJ/mol, and the reaction order is 1.54. The average deviation between the predicted and experimental reaction rate is 4.81%.

Key Words： coal char;catalytic hydrogasification;pressurized fluidized bed;reaction kinetic;random pore model

Abstract:

Keywords:

Foundation: 山西省重点研发计划资助项目(202102090301029);; 山西省基础研发计划青年资助项目(202303021212379,20210302124357);; 省部共建煤基能源清洁高效利用国家重点实验室开放课题资助项目(SKL202103)

Authors: LIU Jiamin;GU Sumin;ZHANG Rong;LI Weiwei;QU Xuan;

DOI: 10.13226/j.issn.1006-6772.YS24010402

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