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Investigation on Reaction Rate of Bituminous Coal-Char Particlesin O2/CO2 Atmosphere in a Fluidized Bed(PDF)

南京师范大学学报（工程技术版）[ISSN:1006-6977/CN:61-1281/TN]

Issue:
2017年04期
Page:
53-
Research Field:
能源与机械工程
Publishing date:

Info

Title:
Investigation on Reaction Rate of Bituminous Coal-Char Particlesin O2/CO2 Atmosphere in a Fluidized Bed
Author(s):
Wang Wenkang1; Bu Changsheng1; Xiong Jinqin1; Wang Xinye1; Zhang Jubing1; Piao Guilin1; Zhang Xiaoyong2
1.School of Energy and Mechanical Engineering,Nanjing Normal University,Nanjing 210042,China)(2.China Datang Corporation Science and Technology Research Institute,Beijing 102206,China
Keywords:
fluidized Bed; O2/CO2 combustion; bituminous coal; combustion; gasification
PACS:
TQ534.2
DOI:
10.3969/j.issn.1672-1292.2017.04.009
Abstract:
Oxy-fuel fluidized bed(FB)combustion is one of the promising technologies achieving the clean utilization of coal and nearly zero emission of CO2 from coal fired power plants. To obtain the oxy-fuel combustion characteristics of coal particles in the industry FB conditions,experimental study of combustion of bituminous coal particles is conducted in a bench-scale FB in O2/CO2 and O2/N2 atmospheres through continuously measuring the concentrations of O2 and CO in the exit gas at the bed temperatures of 800～900 ℃,the O2 concentrations of 4%～10% and the coal particle sizes of 2-8 mm. Results indicate that the combustion rate of bituminous coal-char particle increases with the increase of bed temperature,O2 concentration and the decrease of the coal-char size in O2/CO2 atmosphere. Oxidation of coal-char is controlled by the diffusion of O2,whereas gasification of coal-char is limited by the reaction kinetics. Compared with coal-char combustion in the O2/N2 atmosphere,the decreased diffusivity of O2 in CO2 is the main reason for the changed reaction rate of coal-char particle in O2/CO2 atmosphere at a low bed temperature. However,at a high bed temperature,in spite of the low diffusion rate of O2,the effect of gasification on the coal-char reaction could not be ignored as consequence of the increased gasification rate.

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Last Update: 2017-12-30