Solvent effects on esterification equilibria

Abstract

Solvents are known to have strong impacts on the yields of equilibrium reactions. This work focuses on the thermodynamic investigation of these solvent effects on esterification reactions of acetic acid and propionic acid with ethanol. Esterification of acetic acid was performed in the solvents acetone, acetonitrile (ACN), dimethylformamide (DMF), and tetrahydrofurane as well as in mixtures thereof. ACN promotes the esterification of acetic acid, whereas it is strongly suppressed by DMF. The esterification of propionic acid was investigated with various reactant concentrations in acetone. The experimental equilibrium data in pure solvents and solvent mixtures were modeled using the thermodynamic equilibrium constant Ka and the reactant/product activity coefficients predicted by the perturbed chain‐statistical associating fluid theory (PC‐SAFT). For a given Ka, PC‐SAFT is able to predict the influence of the solvent and even solvent mixtures on the equilibrium concentrations of esterification in almost quantitative agreement with the experimental data. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3000–3011, 2015

Predicting the Solvent Effect on Esterification Kinetics

“…The resulting values are k 1;R1 = 2.45 10 À5 L/(mol s) and k 1;R2 = 1.45 10 À5 L/(mol s). Using K a and k 1 for both reactions, the reactionk ineticso ft he remaining solvent-free systems (1:3, 3:1) and for the reactions in different solvents were predicted via Equations (1) and (2). The activity coefficients g i were predicted using PC-SAFT withoutf itting any model parameters to reaction data.…”

“…A predictive approach for describing solvent effects on reaction equilibria was presented in a previous work of our group by Riechert et al., who investigated the esterification equilibrium of acetic acid (HAc) and of propionic acid (HProp) with ethanol (EtOH) at different reactant ratios and in different solvents. The proposed thermodynamic approach considers the interactions between the reacting species and the different solvents via activity coefficients predicted using the Perturbed‐Chain Statistical Associating Fluid Theory (PC‐SAFT).…”

“…[1] Besides experimental results, they presented at heoretical framework based on the Gibbs energy of solvation that allowed for correlating experimentally obtained apparent equilibrium constants and rate constants with the solvent polarity scale E T (30). However, as these correlations are empirical and specific for ag iven reaction, they cannot be used to predict solvente ffectso no ther reactions than the ones used for obtaining the correlations.Ap redictive approachf or describing solvente ffects on reaction equilibria was presentedi naprevious work of our group by Riechert et al, [2] who investigated the esterification equilibrium of acetic acid (HAc)a nd of propionic acid (HProp) with ethanol (EtOH) at different reactant ratios and in different solvents. The proposed thermodynamic approachc onsiders the interactions between the reacting speciesand the differentsolvents via activity coefficients predictedu sing the Perturbed-Chain Statistical Associating Fluid Theory( PC-SAFT).…”

Predicting solvent effects on the 1‐dodecene hydroformylation reaction equilibrium

“…those involved in the carbon dioxide absorption in aqueous amine solutions 20 . Moreover, PC-SAFT has been shown earlier to be able to predict the solvent effect on esterification reaction equilibria in very good agreement with experimental data 21 .…”

Thermodynamics of Bioreactions

“…Lipases are particularly worthwhile catalysts for esterification reactions, as the presence of a high amount of water dramatically decreases product yield due to equilibrium limitations. Thus, esterifications are usually performed in solvents other than water (e.g., in alcohols) (30,31,117).…”