超临界状态下中高阶变质煤吸附甲烷特性研究  

Study on supercritical methane adsorption characteristics of coal with medium and high rank

作　　者：张明杰[1,2,3] 杨明鑫 闫江伟 解帅龙[2] 梁锡明 李哲 ZHANG Mingjie;YANG Mingxin;YAN Jiangwei;XIE Shuailong;LIANG Ximing;LI Zhe(State Key Laboratory Cultivation Base for Gas Geology and Gas Control,Henan Polytechnic University,Jiaozuo Henan 454003,China;School of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo Henan 454003,China;Collaborative Innovation Center of Coalbed Methane and Shale Gas for Central Plains Economic Region,Jiaozuo Henan 454003,China)

机构地区：[1]河南理工大学河南省瓦斯地质与瓦斯治理重点实验室-省部共建国家重点实验室培育基地,河南焦作454003 [2]河南理工大学安全科学与工程学院,河南焦作454003 [3]中原经济区煤层(页岩)气河南省协同创新中心,河南焦作454003

出　　处：《中国安全科学学报》2021年第8期53-61,共9页China Safety Science Journal

基　　金：国家科技重大专项(2011ZX05040-005);教育部创新团队计划项目(IRT16R22);河南理工大学博士基金资助(B2017-04)。

摘　　要：为揭示中高阶变质煤对超临界甲烷的吸附特性,更准确预测深部煤层气资源量和评判煤层气(瓦斯)抽采效果,选取4个矿区不同变质程度中高阶煤样,采用重量法进行等温吸附试验,并基于过剩吸附理论和Langmuir单层吸附理论,分析甲烷超临界状态下煤吸附甲烷的吸附相密度、吸附甲烷层数和吸附量等吸附特性。结果表明:试验得到的过剩吸附量随压力增大出现峰值;低压状态下,绝对吸附量随压力增加而增大,甲烷在煤表面表现为单分子层排列,接近临界压力4.59 MPa时,增量变缓并趋于稳定,超临界状态下甲烷在煤颗粒表面以单分子层吸附为主,局部逐渐出现2层吸附;同温同压下绝对吸附量与变质程度正相关,无烟煤极限吸附量为中阶烟煤的2倍左右。In order to reveal supercritical methane adsorption characteristics of coal with medium and high rank,more accurately predict coalbed gas resources and evaluate coalbed gas(gas)extraction effect in deep coal seam,four coal samples with different metamorphic degrees were selected to carry out isothermal adsorption tests by gravimetric method.Based on excess adsorption theory and Langmuir monolayer adsorption theory,adsorption phase density,number of adsorption methane layers and adsorption capacity of methane adsorbed by coal were studied under supercritical state of methane.The results show that excess adsorption capacity of coal appears a maximum value with increase of pressure,methane appears in monolayer arrangement on coal surface,absolute adsorption capacity increases with increase of adsorption pressure,and it increases slowly and tends to be stable when adsorption pressure is close to supercritical pressure 4.59 MPa.In supercritical state,methane adsorption on the surface of coal particles is dominated by monolayer,and two layers of adsorption gradually appear locally.Absolute adsorption capacity of anthracite is positively correlated with metamorphic degree at the same temperature and pressure,and ultimate adsorption capacity of anthracite is about twice that of middle-rank bituminous coal.

关 键 词：超临界状态 甲烷吸附 中高阶变质煤 吸附相密度 吸附层数 

分 类 号：X936[环境科学与工程—安全科学]