摘要
文章通过对长焰煤、气煤、焦煤和无烟煤分别吸附CH4、N2和CO2单组分气体的研究,探讨了不同煤 级煤吸附3种单组分气体的特征以及相互间的差异性,发现CO2/CH4和CH4/N2值随煤级和平衡压力的变化而变 化,并非简单的2倍关系。之后评价了几种常用吸附模型模拟煤吸附不同气体的效果,所选模型包括Langmuir方 程、BET方程、D—A方程和D—R方程,优选出了更适合于描述煤吸附气体行为的吸附模型。研究结果表明,n=1 时的D—A方程更适合于描述煤吸附CH4行为,Frendulich方程和Henry方程则适合于描述低煤级煤吸附N2行为, 而所选用的模型都不能合理解释无烟煤吸附CO2的等温线在高压时出现的上翘现象。研究成果在煤层气的资源 评价、产能预测、注气提高煤层气采收率技术以及CO2在煤层中的封存技术等领域具有一定的科学意义。
Through studying the single component gases (CH4, N2 and CO2)' being adsorbed by long flame coal, gas coal, coking coal and anthracite respectively, their characteristics and diversities among them are discussed in the paper. It was found that the ratios of CO 2/CH4 and CH4 /N2 didn' t show a simple relation of two times but changed along with the changes in coal rank and equilibrium pressure. The results of simulating distinct gases' being adsorbed by coals by use of several conventional adsorption models, including Langmuir, BET, D-A and D-R equations, were evaluated, and the adsorption models being more suitable for describing the behaviours of gas' being adsorbed by coal were optimized. The research results indicated that the D-A equation (n = 1) was more suitable for describing the behaviours of the adsorption of coal to CH4; the Frendulich and Henry equations were suitable for describing the behaviours of the adsorption of low-rank coal to N2; but all the selected models couldn' t be used for interpreting reasonably the upwarping phenomenon of the isothermal line of CO2 ' s being adsorbed by anthracite at high pressure. These research results are of great importance to the resource evalua tion and productivity prediction of coalbed methane, the technique of enhancing coalbed methane recovery by gas injection and the technique of CO2 's being sealed in coal beds, etc.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2005年第1期61-65,共5页
Natural Gas Industry
基金
"973"国家重点基础研究发展规划项目"中国煤层气成藏机制及经济开采基础研究"(2002CB11700)资助~~
关键词
长焰煤
气煤
焦煤
无烟煤
CH4
N2
CO2
吸附
Carbon dioxide
Coal
Computer simulation
Engineering research
Fracture
Mathematical models
Methane
Nitrogen
