Abstract Vapor-liquid equilibrium (VLE) measurements of the (CO2 + CH4) system are reported along seven isotherms at temperatures varying from just above the triple point to just below the critical point of CO2 at pressures from the vapor pressure of pure CO2 to approximately 9 MPa, including near-critical states. From these data, the critical locus has been determined and correlated over its entire length. The VLE data are correlated with the Peng-Robinson equation of state (PR-EoS), using a temperature-dependent binary interaction parameter, and also compared with the predictions of the GERG-2008 equation of state. The former represents the phase compositions across all isotherms with a root-mean-square mole-fraction deviation of S = 0.0075 while, for the latter, S = 0.0126. Measurements of the three-phase solid-vapor-liquid equilibrium (SVLE) line are reported at temperatures from approximately (204 to 216) K and a new correlation is developed which is valid from 145 K to the triple point of CO2. Additionally, we report the partitioning of trace levels of H2S between coexisting liquid and vapor phases of the (CO2 + CH4) system and compare the results with the predictions of the PR-EoS.

中文翻译：

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气液平衡、固气液平衡和 H2S 分配系数 (CO2 + CH4) 在 (203.96 和 303.15) K 之间的温度和压力高达 9 MPa

摘要 (CO2 + CH4) 系统的汽液平衡 (VLE) 测量报告沿七个等温线在温度从刚好高于 CO2 的三相点到刚好低于 CO2 的临界点，压力从纯 CO2 的蒸气压到大约9 MPa，包括接近临界状态。从这些数据中，关键基因座已被确定并在其整个长度上相关联。VLE 数据与 Peng-Robinson 状态方程 (PR-EoS) 相关，使用与温度相关的二元相互作用参数，并与 GERG-2008 状态方程的预测进行比较。前者代表所有等温线上的相组成，均方根摩尔分数偏差为 S = 0.0075，而对于后者，S = 0.0126。三相固-汽-液平衡 (SVLE) 线的测量报告在大约 (204 到 216) K 的温度下进行，并且开发了新的相关性，该相关性在 145 K 到 CO2 的三相点之间有效。此外，我们报告了 (CO2 + CH4) 系统共存液相和气相之间痕量 H2S 的分配，并将结果与​​ PR-EoS 的预测进行了比较。