温度对煤吸附甲烷的影响实验

Experiment of the influence of temperature on coalbed methane adsorption

为了研究温度对煤吸附甲烷的影响,实验测定了不同温度下煤对甲烷的吸附等温线,并对实验数据进行了拟合,同时对覆盖度与压力、温度、吸附量以及孔隙类型的关系进行了分析。结果表明:随着温度的增高,饱和吸附量和吸附速率明显降低,并且含气量与覆盖度呈正相关关系;同一压力下,随着温度升高,覆盖度降低;相对覆盖度概念可以解释高温覆盖度高而吸附量小于低温阶段的现象;结合孔隙度和液氮分析结果发现,随着温度的增高,小孔和微孔的吸附能力强于中孔和大孔;甲烷在煤上的等量吸附热随吸附量的增大而增大,但无规律可循,且由Clausius-Clapeyron方程预测出的等温吸附曲线与实测值有偏差,表明煤表面能量的不均匀性和表面离子的复杂性。

Using adsorption experiment we measure adsorption isotherms of coalbed methane at different tempera- tures and fit the experimental data. We discuss the coverage rate and pressure, temperature, pore types and adsorp- tion capacity. The results showed that as the temperature increases, the adsorption capacity and adsorption rate de- crease significantly, and the saturated extent of adsorption has a positive correlation with coverage rate; and as the temperature increases, coverage rate decreases under the same pressure point; the concept of the relative coverage was put forward which can be used to explain the phenomenon that the coverage is higher and the adsorption ca- pacity is less at high temperature than at low-temperature; micropore and mesopore take a leading role in the ad- sorption as the temperature increases; it does not comply with moral law that the adsorption isosteric heat increases as the adsorption capacity increases and the adsorption isotherm predicted by the Clausius-Clapeyron equation was different from the measured value, which indicates the heterogeneity of the coal surface energy and the complexity of the coal surface ions.