低温阶段煤吸附C_(2)H_(4)的吸附特性研究  

Investigation of adsorption characteristics of C_(2)H_(4) from coal in low-temperature stage

作　　者：文虎 李倬锋[1,2] 张铎 唐瑞 黎杰[1,2] WEN Hu;LI Zhuofeng;ZHANG Duo;TANG Rui;LI Jie(College of Safety Science and Engineering,Xi'an University of Science and Technology,Xi'an Shaanxi 710054,China;Shaanxi Key Laboratory of Prevention and Control of Coal Fire,Xi'an University of Science and Technology,Xi'an Shaanxi 710054,China)

机构地区：[1]西安科技大学安全科学与工程学院,陕西西安710054 [2]西安科技大学陕西省煤火灾防治重点实验室,陕西西安710054

出　　处：《中国安全科学学报》2024年第1期94-105,共12页China Safety Science Journal

基　　金：国家自然科学基金资助(51904234)。

摘　　要：为研究煤矿采空区封闭区遗煤吸附C_(2)H_(4)的演化特征,以宁夏灵新煤矿不粘煤为研究对象,采用容量法进行煤吸附C_(2)H_(4)试验,分析温压与粒径对煤吸附C_(2)H_(4)过程中的吸附量、吸附速率和吸附热力学等特征变化的影响。研究表明:当温度为30~60℃、压力为0.15~0.45 MPa、粒径为20~120目时,无论是温度降低、压力升高还是粒径减小,C_(2)H_(4)的吸附量均增加;吸附过程随时间由快变慢,进而趋于平衡,吸附速率快速趋于0;温度与粒径不变,平衡压力越大吸附速率越大;温度与压力不变,粒径越小吸附速率越快。吸附量相同,粒径越小等量吸附热越低;各粒径煤样吸附C_(2)H_(4)的等量吸附热为0.69~40.23 kJ/mol,属于物理吸附。引入压力修正系数进行拟合,温度不变,压力和粒径与吸附自由能降低值呈正比关系;粒径不变,温度与吸附自由能降低值呈反比关系。各粒径煤样吸附C_(2)H_(4)的吸附熵均为负值,吸附量增大,温度降低,吸附熵值均增大;吸附量相同条件下,粒径越大,吸附熵值越大。In order to study the evolution characteristics of adsorption of C_(2)H_(4)by residual coal in closed area of coal mine goaf,taking non-cohesive coal in Lingxin Coal Mine of Ningxia as the research object,the adsorption of C_(2)H_(4) by coal was tested by volumetric method.The effects of temperature,pressure and particle size on the adsorption capacity,adsorption rate and adsorption thermodynamics were analyzed.The results show that when the temperature is 30-60℃,the pressure is 0.15-0.45 MPa and the particle size is 20-120 mesh,the adsorption capacity of C_(2)H_(4) increases with the decrease of temperature,the increase of pressure and the decrease of particle size.The adsorption process changes from fast to slow with time,then tends to equilibrium,and the adsorption rate rapidly tends to 0.When the temperature and particle size are constant,the adsorption rate increases with the increase of equilibrium pressure.When the temperature and pressure are constant,the adsorption rate increases with the decrease of particle size.At the same adsorption capacity,the smaller the particle size is,the lower the equilibrium adsorption heat is.The equivalent adsorption heat of C_(2)H_(4) adsorbed by coal samples with different particle sizes is 0.69-40.23 kJ/mol,which belongs to physical adsorption.The pressure correction coefficient is introduced to fit,and the pressure and particle size are proportional to the reduction of adsorption free energy when the temperature is constant.Under the condition of constant particle size,the temperature is inversely proportional to the decrease of adsorption free energy.The adsorption entropy of C_(2)H_(4) for coal samples with different particle sizes is negative,and the adsorption entropy increases with the increase of adsorption capacity and the decrease of temperature.Under the same adsorption capacity,the larger the particle size,the greater the adsorption entropy.

关 键 词：低温阶段 C_(2)H_(4) 吸附特性 吸附速率 煤自燃 吸附热 

分 类 号：X936[环境科学与工程—安全科学] TD752[矿业工程—矿井通风与安全]