煤对CH_4/CO_2二元气体等温吸附特性及其预测

Characteristics and predictions for adsorption isotherms of methane/carbon dioxide binary gas on coals

研究了晋城煤和潞安煤对CO2和CH4及其二元混合气体的等温吸附特性,利用扩展Langmuir和理想吸附溶液理论结合纯气体等温吸附模型Langmuir,DA,DR,BET对吸附实验数据进行预测,并检验了实验数据的预测准确度.研究结果表明,煤对混合气体的吸附量介于CH4和CO2吸附量之间;煤对混合气体中CH4的吸附量并不是随压力的增加而增加;理想吸附溶液理论结合纯气体吸附等温线对CO2/CH4二元混合气体实验数据预测的准确度要高于扩展Lang-muir,理想吸附溶液理论对混合气体吸附预测的准确度取决于所用的纯气体的等温吸附方程和所预测的煤样煤质指标.

The adsorption isotherms of CH4/CO2 experimental data were predicted with expended tion with pure gas tal data was inves dioxide binary gas on Jincheng and Lu＇an coal were studied, and Langmuir and ideal adsorbed solution theory （IAST） in conjuncisotherm models viz. Langmuir, DA, DR, BET, and the prediction accuracy for the experimentigated. The study results show that the adsorption capacity of mixed gas on coals is between that of pure CH4 and CO2, the adsorbed quantity of methane for binary gas on coals do not increase with the increase of pressure, IAST combined with pure gas isotherm equations are more accurate for the prediction of mixed gas adsorption isotherms than extended Langmuir, that prediction accuracy for IAST are dependent upon the choice of pure gas isotherm equation employed and the coal quality indexes of coal samples predicted.