基于空位溶液与DA理论的多组分气体吸附方法及验证

Method of multi-component gas adsorption based on vacancy solution and DA theory and its verification

为准确预测煤层气中多组分气体的吸附性能,将空位溶液与Dubinbin-Astakhov(DA)理论相结合,提出1种适用于煤层气吸附系统的多组分混合吸附模型。在模型中,吸附体系被视为气体与假设的“空位溶质”的多元混合物,吸附体系视为气相和吸附相空位溶质之间的平衡。结果表明:根据单组分气体吸附等温线,采用D-A方程计算分析了生成二元(吸附质+空位)混合物中纯组分气体的活度系数,并优化吸附参数;模型能够根据在单一温度下收集的纯组分吸附数据预测不同温度下的多组分气体吸附;模型计算结果与实测结果吻合良好,误差在10%以内,充分说明模型是切实可靠的。

In order to accurately predict the adsorption performance of multi-component gas in the coalbed methane,a multi-component mixed adsorption model suitable for the coalbed methane adsorption system was proposed by combining the bacancy solution and the Dubinbin-Astakhov(DA)theory.In the new model,the adsorption system was regarded as the multi-component mixture of gas and hypothetical“vacancy solute”,and the adsorption system was regarded as the equilibrium between the gas phase and the vacancy solute in the adsorption phase.The results showed that according to the adsorption isotherm of single component gas,the DA equation was used to calculate and analyze the activity coefficient of pure component gas in the generated binary(adsorbate+vacancy)mixture,and the adsorption parameters were optimized.The model could predict the multi-component gas adsorption under different temperatures according to the pure component adsorption data collected under single temperature.The calculated results of the new model were in good agreement with the measured results,and the error was within 10%,which fully presented that the new model was practical and reliable.