Abstract Liquid storage is a potential method for low-pressure storage of natural gas. In this work, octamethylcyclotetrasiloxane (OMCTS) was selected as a solvent for methane storage. Experimental measurements were carried out in a Cailletet apparatus, according to the synthetic method, from low to high pressures. One hundred experimentally-measured phase equilibrium data points are presented for methane + OMCTS in the form of bubble-points. The pressure, temperature, and methane mole fraction ranges are (0.61–8.07) MPa, (287.73–368.25) K, and (0.0534–0.4038), respectively. Furthermore, phase equilibrium calculations based on the φ − φ approach were carried out to model the methane + OCMTS binary system. In this regard, the Peng-Robinson EoS (PR EoS), coupled with the classical van der Waals (vdW) mixing rule, was applied. The vdW mixing rule was used in three modes: a) with no binary interaction parameters ( k i j = 0 , l i j = 0 ), b) with one constant binary interaction parameter ( k i j = c o n s t a n t ), and c) with one temperature-dependent binary interaction parameter ( k i j = a + b T ). It was concluded that both modes (b) and (c) give accurate results for methane solubility in OMCTS, with A A D ( M P a ) values of 0.11 and 0.10, respectively.

中文翻译：

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八甲基环四硅氧烷中甲烷的溶解度：实验测量和热力学建模

摘要 液体储存是天然气低压储存的一种潜在方法。在这项工作中，八甲基环四硅氧烷（OMCTS）被选为甲烷储存的溶剂。根据合成方法，在 Cailletet 装置中进行实验测量，从低压到高压。甲烷 + OMCTS 的一百个实验测量的相平衡数据点以泡点的形式呈现。压力、温度和甲烷摩尔分数范围分别为 (0.61–8.07) MPa、(287.73–368.25) K 和 (0.0534–0.4038)。此外，还进行了基于 φ - φ 方法的相平衡计算，以模拟甲烷 + OCMTS 二元系统。在这方面，应用了 Peng-Robinson EoS (PR EoS) 以及经典的范德华 (vdW) 混合规则。vdW 混合规则用于三种模式：a) 没有二元相互作用参数（ kij = 0 , lij = 0 ），b）有一个常数二元相互作用参数（ kij = constant ），和 c) 有一个温度相关的二元相互作用参数交互参数（ kij = a + b T ）。得出的结论是，模式 (b) 和 (c) 都给出了 OMCTS 中甲烷溶解度的准确结果，AAD ( MP a ) 值分别为 0.11 和 0.10。