煤焦气化反应动力学研究

气流床气化技术是煤炭清洁、高效转化的重要途径和发展方向之一。利用热天平,采用等温热重法对抽样选出的煤种在800℃～1 400℃温度范围内进行了煤焦CO2气化反应动力学特性研究。研究结果表明:高温下煤焦的气化反应特性不同于低温时的反应特性,在900℃～1 000℃时气化反应逐步由化学反应控制过渡到过渡区控制,在1 100℃～1 300℃时气化从反应过渡区控制逐步到扩散区控制;不同粒径的煤粉气化反应,在相同的时间内,1 000℃时的碳转化率、气化反应速率比950℃时的碳转化率、气化反应速率高很多,950℃时的碳转化率、气化反应速率比900℃时的碳转化率、气化反应速率高。

Study on Reaction Kinetics of Char Gasification

The entrained flow coal gasification technology with high pressure and large scale has become one of the important means and directions in clean coal and coal conversion technology in the future.Based on the extensive investigation of coal ash fusion characteristics of main coal mining area in China,the coal char CO₂ gasification reaction characteristics of selected coal samples were studied with isothermal thermo-gravimetry method by using TGA in 800 ℃～1 400 ℃.The results were shown that the coal char gasification reaction characteristics at high temperature were different from the condition of at low temperature,the reaction control step is transferred from chemical reaction control zone to transition zone at around 900 ℃～1 000 ℃ and from transition zone to pore diffusion control zone at around 1 100 ℃～1 300 ℃.The carbon conversion and reaction rate is higher in 1 000 ℃ than in 950 ℃ and the carbon conversion and reaction rate is higher in 950 ℃ than in 900 ℃.