利用量子力学势能数据预测温度、压力、盐度和沉积物孔径对甲烷水合物形成和分解的影响

A thermodynamic model based on ab initio intermolecular potential to predict the equilibrium condition of methane hydrate under the influence of temperature,pressure,salinity and capillary force

介绍一个预测不同温度、压力、盐度和沉积物毛细管孔径条件下甲烷水合物-溶液-气体多相平衡模型。该模型以VanderWaals和Platteeuw热力学模型、量子力学从头算粒子相互作用势能、DMW-92状态方程和Pitzer电解质理论为基础,能在很宽广温压范围内预测温度、压力、盐度和毛细管力对甲烷水合物形成和分解的影响。通过对比本模型的预测结果与实验数据,可知本模型能够准确地预测海水和多孔介质中甲烷水合物的相平衡条件。对于一定盐度下多孔介质中甲烷水合物的形成温压条件的在线计算可浏览:www.geo-chem-model.org/models.htm。

A thermodynamic model is presented for predicting the multi-phase equilibria of methane hydrate,liquid and vapor phases under conditions of different temperature,pressure,salinity and pore sizes.The model is based on Van der Waals-Platteeuw model,angle-dependent ab initio intermolecular potentials,DMW-92 equation of state and Pitzer theory.Comparison with the experimental data shows that this model can predict the equilibrium p-T condition of CH4 hydrate in seawater and porous media with high accuracy.Online calculations of the p-T condition for the formation of methane hydrate at a given salinity and pore sizes of sediments is available on：www.geochem-model.org/models.htm.