甲烷在石墨化炭黑上吸附平衡的分子模拟

Gcmc simulation of methane adsorption equilibria on graphitized carbon black

采用GCMC法对不同温度和压力下纯CH4在石墨化炭黑上的吸附平衡进行了分子模拟研究，选用Lennard-Jones 12—6势能函数和联合原子力场参数（TraPPE）对体系进行势能计算，并将吸附平衡预测结果与实验数据进行了比较分析。结果表明，在所研究的温度范围内，除了在低压的一定区间外，GCMC模拟结果在中压和高压条件下与实验数据基本吻合，表明采用GCMC方法模拟甲烷分子在石墨化炭黑上的吸附平衡数据是可以进行准确预测的。在此基础上，利用模拟的吸附平衡数据计算不同温度下CH4的Henry常数进而到得极限吸附热，计算结果与实验数据接近。

The adsorption equilibria of pure methane on the graphitized carbon black were simulated using the GCMC（grand canonical ensemble Monte Carlo） method with wide ranges of temperature and pressure. The potential energy of this system was calculated according to the 12-6 Lennard-Jones potential function and Transferable Potentials for Phase Equilibria Force Field（TraPPE） parameters. The predicted adsorption isotherms have been analyzed with the experiment data. The investigation demonstrates that the adsorption prediction by the GCMC is in good agreement with experimental data at various temperatures except in the low-pressure range, which shows the GCMC method is valid for prediction of methane adsorption on the graphitized carbon black. In addition, the Henry constants have been calculated to obtain the isosteric heat at zero loading. The comparison between the predicted value and the experimental value is satisfactory.