摘要
为了深入研究CO2对煤低温氧化反应的影响,利用程序升温油浴实验装置,研究在不同CO2浓度下煤样的自燃特性.采集南屯矿煤样,破碎并筛分出混合平均粒径为4.18 mm的煤样,向试验管煤样中通入不同配比的混合气体,实验控制升温速度为0.3℃/min,供气量为190 mL/min.测定在6种不同浓度CO2气氛下的煤样低温氧化特性,实验结果表明：CO2浓度越高,煤样耗氧速率越小,CO产生率降低.在起始阶耗氧速率相差不大,煤氧复合作用以物理吸附和化学吸附为主,后期阶段以化学反应为主,变化明显.相比于空气气氛下,CO2气氛下煤样活化能有所提高,在40 ～100℃的温度范围内煤氧作用的活化能值由17.85 kJ/mol升高至22.71 kJ/mol,氧化反应速率降低,表明CO2的加入降低了煤的氧化反应速率,抑制了煤的氧化反应.
In order to study the effect of CO2 on low temperature oxidation of coal, the characteristics of coal spontaneous combustion under different CO2 concentrations were studied using the experiment device of temperature programming oil bath. Nantun coal sample was collected, the coal sample of mixed average particle size of 4.18 mm was crushed and sieved. The different proportion of mixed gas was passed into the test tube of coal samples, test control temperature is 0.3 ℃ /min, gas supply is 190 mL/ min. The low temperature oxidation characteristics of coal samples under six different concentrations of CO2 atmosphere were measured. The experimental results show that： The higher the CO2 concentration, the smaller coal sample oxygen consumption rate, the lower CO production rate. There is little difference in the initial stage,the effects of coal and oxygen mainly include physical adsorption and chemical adsorption, there are significant changes in the later stage, this stage is mainly dominated by chemical reactions. Compared to the air atmosphere, the activation energy of coal sample increased under CO2 atmosphere. The activation energy of the effects of coal and oxygen was elevated from 17.85 kJ/mol to 22.71kJ/mol in the range of 40 - 100 ℃ temperature, the rate of oxidation reaction reduced. This shows that adding CO2 reduces the rate of coal oxidation reaction and inhibits the oxidation reaction.
出处
《西安科技大学学报》
CAS
2014年第4期379-383,共5页
Journal of Xi’an University of Science and Technology
基金
国家自然科学基金资助项目(51204135)
973计划前期研究项目(2011CB411902)
陕西省自然科学基金资助项目(2011JY018)
关键词
CO2
煤自燃
低温氧化
耗氧速率
CO
CO2
coal spontaneous combustion
low temperature oxidation
oxygen consumption rate
