Henry's Law Constants of Methane, Nitrogen, Oxygen and Carbon Dioxide in Ethanol from 273 to 498 K: Prediction from Molecular Simulation

TL;DR

This study predicts Henry's law constants for methane, nitrogen, oxygen, and carbon dioxide in ethanol across a temperature range using molecular simulation, achieving good agreement with experimental data.

Contribution

The paper introduces a new rigid anisotropic united atom model for ethanol and demonstrates accurate prediction of Henry's law constants without extensive binary data.

Findings

Predictions agree within 20% for most gases

Deviations reach 70% for CO2 without modifications

Modified combining rule improves accuracy significantly

Abstract

noindent Henry's law constants of the solutes methane, nitrogen, oxygen and carbon dioxide in the solvent ethanol are predicted by molecular simulation. The molecular models for the solutes are taken from previous work. For the solvent ethanol, a new rigid anisotropic united atom molecular model based on Lennard-Jones and Coulombic interactions is developed. It is adjusted to experimental pure component saturated liquid density and vapor pressure data. Henry's law constants are calculated by evaluating the infinite dilution residual chemical potentials of the solutes from 273 to 498K with Widom's test particle insertion. The prediction of Henry's Law constants without the use of binary experimental data on the basis of the Lorentz-Berthelot combining rule agree well with experimental data, deviations are 20%, except for carbon dioxide for which deviations of 70% are reached. Quantitative agreement is achieved by using the modified Lorentz-Berthelot combining rule which is adjusted to one experimental mixture data point.