超临界二氧化碳与二苯醚相平衡研究

为了解决煤焦油及其轻质化产物中二苯醚的萃取精馏分离问题以及为后续的高效分离过程提供工程数据，本文自行设计并搭建了一套流动法可视化高温高压相平衡测定装置，对二苯醚-二氧化碳体系的相平衡数据进行了测定，测定温度为313.15K、333.15K和353.15K，测定压力为8～18MPa，并使用Peng-Robinson (PR)和Soave-Redlich-Kwong（SRK）状态方程结合Quadratic、Adachi-Sugie、Mathias-Klotz-Prausnitz混合规则对的超临界二氧化碳与二苯醚相平衡数据进行了关联计算，关联结果表明PR和SRK状态方程结合AS混合规则可以获得较为准确的关联结果，而传统二次型混合规则得到的计算结果误差相对较大。此外，关联计算还表明，选择合适的混合规则后，不同状态方程的关联结果相差不大。这表明，对于低挥发性的液体与二氧化碳这类非对称混合物体系，相平衡模拟计算的关键在于选取合适的混合规则。

Phase equilibrium for binary system of diphenyl ether-supercritical carbon dioxide

In order to solve the problem of separating diphenyl ether in tar and its upgrading products, the phase equilibrium for diphenyl ether-carbon dioxide were measured at 313.15—353.15K in the pressure ranges of 8—18MPa, which provided fundamental information for designing separation process. The phase equilibrium data were measured by a flow-type visualization apparatus at high pressure. The measured data were correlated using the Peng-Robinson (PR) and Soave-Redlich-Kwong (SRK) equations of state (EOS) in combination with the mixing rules of Quadratic, Adachi-Sugie (AS) and Mathias-Klotz-Prausnitz (MKP). The correlation results demonstrated that PR and SRK equations of state with the AS mixing rule can obtain relatively accurate correlation results, whereas the traditional quadratic mixing rule lead to relatively large errors in the ranges investigated. In addition, the correlation also showed that after selecting the appropriate mixing rule, the selection of the EOS had little effect on the correlation result. It can be concluded that as for the asymmetric mixtures such as low volatility liquids and carbon dioxide, the key to simulate the phase equilibrium was the selection of appropriate mixing rules.