New Model to Predict Infinite Dilution Activity Coefficients Based on (∂p/∂x)

Area of Science:

• Thermodynamics
• Physical Chemistry
• Chemical Engineering

Background:

• Accurate prediction of infinite dilution activity coefficients (γ^∞) is crucial for molecular thermodynamics.
• Existing models face challenges in predicting γ^∞ for aqueous systems.

Purpose of the Study:

• To develop a novel, accurate model for predicting infinite dilution activity coefficients (γ^∞) in aqueous solutions.
• To establish a model applicable across various temperatures.

Main Methods:

• Utilized a group contribution method to estimate (∂p/∂x)_T.
• Established a relationship between (∂p/∂x)_T and γ^∞ at low pressure.
• Validated the model using extensive experimental data (46 systems, >450 data points).

Main Results:

• Achieved a total average relative deviation of 4.73% for training data.
• Demonstrated satisfactory predictive performance on unseen data.
• Outperformed UNIFAC, modified UNIFAC, and other predictive models for aqueous systems.

Conclusions:

• The developed model provides accurate predictions of γ^∞ in aqueous solutions.
• The model's simplicity facilitates its application in engineering practices.
• This approach offers a superior alternative to existing models for thermodynamic property calculations.