Papadimitriou N I, Tsimpanogiannis I N, Stubos A K
Environmental Research Laboratory, National Center for Scientific Research Demokritos, 15310 Agia Paraskevi, Greece.
J Chem Phys. 2009 Jul 28;131(4):044102. doi: 10.1063/1.3160767.
We develop a methodology to calculate the gas storage capacity of binary hydrates stabilized by promoters. This model utilizes equilibrium experimental data of both hydrates (i.e., the hydrate of pure promoter and the binary hydrate of gas and promoter) in order to calculate the gas occupancy in the small cavities that are not occupied by the promoter. The new approach, although based on the traditional van der Waals-Platteeuw theory, has two significant advantages. The hypothetical state of an empty hydrate for the calculation of the chemical potential of water is replaced by the hydrate of the pure promoter whose properties can be determined through simple thermodynamic calculations. In addition, the computational difficulties related to the complete occupancy of the large cavities by the promoter are removed. The proposed methodology is applied to calculate the gas storage capacity of hydrates of two energy-carrier gases (methane and hydrogen) stabilized by tetrahydrofuran. Excellent agreement is observed between the proposed-model predictions and published experimental values for the gas content of hydrates.
我们开发了一种方法来计算由促进剂稳定的二元水合物的储气容量。该模型利用水合物（即纯促进剂的水合物以及气体与促进剂的二元水合物）的平衡实验数据，以计算未被促进剂占据的小空腔中的气体占有率。这种新方法虽然基于传统的范德华 - 普拉特奥理论，但有两个显著优点。用于计算水的化学势的空水合物的假设状态被纯促进剂的水合物所取代，其性质可通过简单的热力学计算确定。此外，消除了与促进剂完全占据大空腔相关的计算困难。所提出的方法被应用于计算由四氢呋喃稳定的两种能量载体气体（甲烷和氢气）水合物的储气容量。在所提出的模型预测与已发表的水合物气体含量实验值之间观察到了极好的一致性。
