水合物生成条件下甲烷在水中的吸附

采用悬滴法系统地测定了温度274.2 ~ 282.2 K、压力0.1 ~ 10.1 MPa下甲烷/纯水间界面张力。实验结果表明在恒定温度下界面张力随压力的增加而增大。在高压条件下，压力对界面张力有很大的影响。不同温度和压力下计算出的甲烷在水中的表面过剩浓度结果表明，压力越高，温度越低，甲烷在水溶液中的吸附浓度越高。同时，计算出的甲烷在水溶液中的表面吸附自由能结果表明，在水合物生成条件下，甲烷在水中的吸附比298.2 K更容易。

Adsorption of Methane on Water under Hydrate Formation Conditions

The variation of interfacial tension with pressure has been determined systemically for water in equilibrium with compressed methane at temperature from 274.2 to 282.2 K in the range of pressure from 0.1 to 10.1 MPa using the pendant‐drop method. The results show that the interface tension decreased with increasing pressure when temperature was specified. Pressure has a great influence upon the interface tension at higher pressure. The surface excess concentrations of methane on water at different temperatures and pressures were calculated. The results showed that higher pressure and lower temperature corresponded to higher adsorption concentration of methane. At the same time, the surface adsorption free energies of methane were also calculated, indicating that the adsorption of methane on water under hydrate formation condition is more preferable than that at 298.2 K.