Structure-H hydrate of mixed gases: Phase equilibrium modeling and experimental validation
Structure-H hydrate of mixed gases: Phase equilibrium modeling and experimental validation
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DOI：
10.1016/j.molliq.2021.117605
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发表时间：
2021-10-04
影响因子：
6
通讯作者：
Jana, Amiya K.
中科院分区：
文献类型：
--
作者：
Dhamu, Vikas;Thakre, Niraj;Jana, Amiya K.
笼形水合物是一种固态的冰状化合物，它能将气体或液体分子困在由氢键水分子组成的空腔中。与常用的sI和sII结构的笼形水合物相比，sh型具有更高的稳定性和气体吸收能力。尽管混合气体的sh型水合物在气体储存和分离中具有丰富的意义，但由于对客组分之间相互作用的估计不准确，用于预测其形成条件的相平衡模型在文献中很少可用。在这种观点下，我们开发了一种新的方法，使用扩展到三参数Patel-Teja状态方程的Wong-Sandler混合规则，结合基于统计热力学的van der Waals和Platteeuw模型来定义水合物相。除此之外，使用Patel-Teja模型而不是经验相关性来估计辅助气体在水中的溶解度。结果表明，该公式能够在1.389- 2.812%的AARD范围内预测以甲烷、氮或二氧化碳为共客体的各种水合物（即新己烷、甲基环戊烷、异戊烷、2,2-二甲基戊烷和最近发现的第一气相重原四氟环丁烷）的实验相平衡数据。(C) 2021年由Elsevier B.V.出版
Clathrate hydrates are solid ice-like compounds that entrap the gas or liquid molecules into their cavities of hydrogen-bonded water molecules. As compared to commonly available sI and sII structures of clathrate hydrate, the sH-type is reported to possess more stability and gas uptake capacity. Despite copious implications of the sH-type hydrates of mixed gases in gas storage and separation, the phase equilibrium modeling to predict their formation condition is rarely available in the literature due to inaccurate estimation of the interactions between the guest components. In this view, we develop a novel methodology using the Wong-Sandler mixing rule extended for the three-parameter Patel-Teja equation of state, in association with the statistical thermodynamics based van der Waals and Platteeuw model to define the hydrate phase. This apart, the solubility of the help gases in water is estimated using the Patel-Teja model instead of the empirical correlations. It is observed that the proposed formulation is capable of predicting the experimental phase equilibrium data with a range of 1.389-2.812 %AARD for a variety of sH hydrates (i.e., neohexane, methylcyclopentane, isopentane, 2,2-dimethylpentane and a recently discovered first vapor phase heavy former tetrafluorocyclobutane) having methane, nitrogen or carbon dioxide as their co-guest. (C) 2021 Published by Elsevier B.V.