Development of new activity coefficient equation for correlation to estimation equation for multi-component systems

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05195
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 27010:Transport phenomena and unit operations-related
• Research Institution: Kyushu University
• Principal Investigator: IWAI Yoshio 九州大学, 工学研究院, 准教授 (80176528)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 新しいGEモデル / CPGE / Cubic Plus GE / 状態方程式 / 活量係数モデル / 気液平衡 / 第二ビリアル係数制限条件満足

Outline of Final Research Achievements

The excess Gibbs energy term obtained from interaction contributions of activity coefficient models is added to a cubic equation of state. A simple mixing rule was applied to the constants in the equation of state, and the coefficients of the additional term were obtained by dimensional analysis. In the low-pressure liquid-phase state, the coefficients are set to the same form as the commonly used activity coefficient models, and in the gas-phase, the limiting condition of second virial coefficient is satisfied. The temperature dependence of vapor-liquid equilibria of binary systems are well correlated by setting the remaining constant s to 1.15 in the dimensional analysis. Furthermore, the parameters obtained from the vapor-liquid equilibria of binary systems are shown to provide a good estimation of the vapor-liquid equilibria of the multi-component system.

Free Research Field

化学工学

Academic Significance and Societal Importance of the Research Achievements

活量係数モデルより求められる過剰ギブスエネルギー項を3次型状態方程式に結びつけるモデルは今まで存在したが、それらのモデルは、気相で第二ビリアル係数の制限条件を満足していないか、満足していても状態方程式中の定数の混合則が不自然なくらい複雑か、のどちらかであった。本研究で提案したモデルは、気相で第二ビリアル係数の制限条件を満足し、かつ状態方程式中の定数の混合則が単純である新しいモデルであり、学術的意義は大きい。さらに、このモデルにより気液平衡計算が良好に行えることから、蒸留塔などの分離装置の設計に応用でき、社会的意義も大きい。