一种炼焦煤尾煤热重动力学分析及热解产富氢气体  

Characteristics and kinetics of the pyrolysis of coke-tailings

作　　者：刘海兵[1] 郭战英[1] 惠贺龙[1] 付兴民[1] 柳树成[1] 李成[1] 舒新前[1] 

机构地区：[1]中国矿业大学化学与环境工程学院,北京100083

出　　处：《安全与环境学报》2012年第5期77-81,共5页Journal of Safety and Environment

基　　金：国家自然科学基金项目(90610014;51108453)

摘　　要：基于热重分析试验和固定床热解试验,研究了升温速率和温度对高矿物质含量的炼焦煤尾煤热解特性的影响。尾煤热解过程可分为室温～400℃、400～600℃及600～950℃3个阶段。采用Coats-Redfern积分法拟合计算了尾煤热解的动力学参数,表明炼焦煤尾煤热解反应过程可以用3个二级反应进行描述,其热解反应活化能介于22.6～66.2 kJ/mol。固定床试验结果表明,温度对尾煤挥发分的析出有重要影响,高温有利于尾煤中高分子有机组成裂解和挥发分析出,最终决定了尾煤的热解反应进程。600℃前气体缓慢析出,之后,随温度升高,气体产量和热值增加显著,H2和CO随温度升高而增加,CH4和CO2先增加后减少。H2在600℃前析出缓慢,600℃后大量析出,在900℃左右达到最大析出量,贯穿整个反应过程。CO在900℃左右达到最大析出量;CH4和CO2在800℃左右达到最大值,之后开始下降。终温950℃时,30 g尾煤热解产气4 300 mL,H2产量1 722mL;焦煤产气7 950mL,H2产量2716mL。尾煤热解富H2体产量达焦煤热解气产量的54%,具有较高的再利用价值。The paper is aimed at introducing our investigation results of the influence of heating rate and high temperature on the characteristic features of the mineral content of the coke-coal tailings on the basis of thermogravimetric analysis and the fixed bed pyrolysis experiments. The TG results have shown that the pyrolysis process of tailings can be divided into three stages： the initial heating from 400℃, and the next stage at the temperature range from 400℃ to 600℃, and the third stage, the stage of pyrolysis from 600-950℃.According to the tailing pyrolysis kinetics model, we have worked out the Coats-Redfern equation, hoping to prove that the activation energy of the pyrolysis of the coking coal tailings is 22.6-66.2 kJ/mol and the process of pyrolysis can be taken as three second-order reactions. The fixed bed experimental results show that the strong heating temperature serves as an important influential factor on the evolution of the tailings volatile. In addition, it is also a decisive factor that can conduce to the decomposition of the metal under work and the precipitation of organic polymers and volatile in the tailings. The reaction process is naturally determined by the final extremely high temperature. In the pyrolysis of the tailings, the volatile matter wouldn＆rsquo;t be precipitated quickly until 600℃, but beyond it, with the continuous temperature rising, the yield and calorific value of the melted gases tend to increase abruptly. With the quick rise of temperature, hydrogen increases, with carbon monoxide, methane and carbon dioxide first rising and then dropping. The actual process goes in the way that hydrogen precipitates slowly at about 600℃, it would precipitate violently and soon reach the maximum at 900℃ through the entire reaction process. As to carbon monoxide, it tends to reach its maximum at about 900℃ and methane at about 800℃ as well as carbon dioxide. The yields of gas and hydrogen are respectively 4 300 mL and 1 722 mL, at the finial temperature of 950℃ by 30

关 键 词：环境工程学 炼焦煤尾煤 热解 动力学 

分 类 号：X705[环境科学与工程—环境工程]