Prediction of Liquid–Liquid Equilibria for Biofuel Applications by Quantum Chemical Calculations Using the Cosmo-SAC Method

Abstract

Currently, there is a great interest in the production of biofuels such as biodiesel, bioethanol and biobutanol. These processes involve liquidÀliquid equilibria, which are important for the overall design of the process. However, suitable experimental data are often scarce. The Cosmo-SAC model provides a method to predict liquidÀliquid equilibrium data from quantum chemical calculations without any experimental data. Hence, it can be used to provide initial estimates where experimental data are not available. In this work, we have evaluated the Cosmo-SAC model for the liquidÀliquid equilibria involved in biodiesel production and bioalcohol extraction using ionic liquids, and we have compared it with the currently available experimental data. THE COSMO-SAC METHOD2.1. Introduction. The Cosmo-SAC method uses quantum chemical calculations for the determination of thermodynamic Special Issue: Ananth Issue

Experiments and COSMO-SAC Modeling of Methyl Isobutyl Ketone + Dimethylphenols + Water Mixtures

“…However, the COSMO-SAC model predicts LLE experiments requiring only initial feed point data, which saves the experiment time and difficulty. Previously, many papers reported prediction of LLE experiments using COSMO-SAC model and achieved good results. ,, On the basis of COSMO-SAC theory, the activity factor of solute i in solvent S (γ i/S ) can be calculated by where Δ G * res denotes the restoring free energy from the chemical potential of segment in the COSMO-RS model, γ i/S SG is calculated by the Staverman–Guggenheim combinatorial term.…”

“…Hydrogen-bonding atoms were defined as nitrogen, oxygen, fluorine atoms, and hydrogen atoms combined with oxygen, nitrogen, fluorine atoms in a pure substance, and others were non-hydrogen bond atoms . A detailed description of COSMO-SAC model was published in refs. ,,,, …”

Measurement, correlation and COSMO-SAC prediction of liquid-liquid equilibrium for the ternary systems, mesityl oxide + o-, m-, p-cresol + water, at 333.2K and 353.2 K

“…Second, calculate the activity coefficients of each pure compound and mixture by using the σ-profile p(σ). The details of the COSMO-SAC model can be found in other publications [32,40,41] and in the Appendix. The COSMO-SAC universal parameter for the effective contact area a eff in this work is 6.55Å 2 , while the hydrogen bonding coefficient c hb is 100 kcalÅ 4 mol -1 e -2 .…”

Prediction of sorption in polymers using quantum chemical calculations: Application to polymer membranes

“…They have been applied to a wide range of compounds ranging from simple nonpolar solvents to ionic liquids [35][36][37][38][39][40][41][42] and have shown significant promise in prediction of phase equilibria of these compounds. However, the application of these models to polymer phase equilibria is scarce [43,44], mainly because the quantum chemical calculations for polymers are computationally very intensive.…”