Abstract The present study aims to implement an electrolyte EoS developed in our previous work [A. Raeispour Shirazi, M. N. Lotfollahi, Fluid Phase Equilib., 502 (2019) 112289] to model the vapor-liquid equilibria (VLE) of CO2 solubility in aqueous N-methyldiethanolamine (MDEA) solution (CO2+MDEA+H2O ternary mixture) as well as H2O+MDEA+CO2-CH4 quaternary mixture. The proposed electrolyte PC-SAFT+MSA+Born equation of state ((ePC_SAFT-MB) consists of PC-SAFT equation of state, the mean spherical approximation (MSA) term and the Born term. First, an appropriate association scheme for water is specified via performing VLE calculations for H2O-CO2 binary mixture and without any adjustment in binary interaction parameter (BIP). By determining the proper association scheme for water (4C), the BIPs of H2O-CO2, MDEA-CH4 and CH4-H2O binary mixtures are adjusted with binary VLE experimental data. In what follows, the nonelectrolyte PC-SAFT EoS is applied considering the obtained BIPs to predict 162 selected data points of bubble pressure for H2O-MDEA-CO2 ternary system in a wide range of temperature (298-413 K), MDEA concentration (18.7-48.8 wt.%) and CO2 loading (0.0001-1.5). The average absolute relative deviation (AAD%) for the calculation results is obtained 25.9%. In order to consider the ions interactions in the solution and to improve the precision of calculations, Born and MSA contributions are added to PC-SAFT EoS. By adjusting two BIPs ( k M D E A H + − − C O 2 and k M D E A H + − H C O 3 − ) and without any readjustment of other BIPs, the AAD% is obtained 15.3%. Finally, the obtained BIPs between the molecular and ionic species for proposed ePC_SAFT-MB EoS are employed to predict the VLE of H2O-MDEA-CO2-CH4 quaternary mixture without any readjustment in BIPs. For this case, the AAD% of 28.05% indicates the reliability of proposed ePC_SAFT-MB EoS for the prediction of H2O-MDEA-CO2-CH4 quaternary VLE results.

中文翻译：

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ePC_SAFT-MB EoS 在预测 CO2+MDEA+H2O 三元和 H2O+MDEA+CO2-CH4 四元混合物 VLE 中的应用

摘要本研究旨在实施我们之前工作中开发的电解质 EoS [A. Raeispour Shirazi, MN Lotfollahi, Fluid Phase Equilib., 502 (2019) 112289] 模拟 CO2 在 N-甲基二乙醇胺 (MDEA) 水溶液（CO2+MDEA+H2O 三元混合物）中溶解度的汽液平衡 (VLE)作为 H2O+MDEA+CO2-CH4 四元混合物。提出的电解质 PC-SAFT+MSA+Born 状态方程 ((ePC_SAFT-MB) 由 PC-SAFT 状态方程、平均球面近似 (MSA) 项和 Born 项组成。首先，水的适当关联方案是通过对 H2O-CO2 二元混合物执行 VLE 计算而不对二元相互作用参数 (BIP) 进行任何调整来指定。通过确定水 (4C) 的适当关联方案，H2O-CO2 的 BIP，MDEA-CH4 和 CH4-H2O 二元混合物使用二元 VLE 实验数据进行调整。在下文中，考虑获得的 BIP，应用非电解质 PC-SAFT EoS 来预测 162 个选定的 H2O-MDEA-CO2 三元系统气泡压力数据点在很宽的温度范围 (298-413 K)、MDEA 浓度 (18.7 -48.8 wt.%) 和 CO2 负载 (0.0001-1.5)。计算结果的平均绝对相对偏差 (AAD%) 为 25.9%。为了考虑溶液中的离子相互作用并提高计算精度，PC-SAFT EoS 中添加了 Born 和 MSA 贡献。通过调整两个 BIP（k MDEAH + - - CO 2 和 k MDEAH + - HCO 3 - ）并且没有对其他 BIP 进行任何重新调整，AAD% 为 15.3%。最后，所提出的 ePC_SAFT-MB EoS 的分子和离子物种之间获得的 BIP 用于预测 H2O-MDEA-CO2-CH4 四元混合物的 VLE，而无需在 BIP 中进行任何重新调整。对于这种情况，28.05% 的 AAD% 表明所提出的 ePC_SAFT-MB EoS 用于预测 H2O-MDEA-CO2-CH4 四元 VLE 结果的可靠性。