Influence of solvent and salt on kinetics and equilibrium of esterification reactions. (14th December 2022)

• Record Type: Journal Article
• Authors: Pabsch, Daniel; Lindfeld, Johanna; Schwalm, Janika; Strangmann, Alexander; Figiel, Paul; Sadowski, Gabriele; Held, Christoph
• Is Part Of: Chemical engineering science. Volume 263(2022)
• Publication Date: 2022-12-14
• Subjects: Electrolyte thermodynamics -- Reaction equilibrium -- Reaction kinetics -- ATR-FTIR spectroscopy -- Thermodynamic modeling -- Predictions; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2022.118046
• Languages: English
• ISSNs: 0009-2509

Abstract

Graphical abstract: Highlights: New data on the esterification of acetic acid and of propionic acid with ethanol. Development of an activity-based kinetic approach using thermodynamic modeling. Activity-based rate constants and equilibrium constants were determined. Kinetics and equilibrium were predicted as function of solvent and salt addition. The activity coefficient of the acid explained the effects on the reaction kinetics. Abstract: The influence of the solvent N -methyl-2-pyrrolidone (NMP) and the salt LiCl on the esterification of acetic acid (HAc) or propionic acid (HProp) with ethanol (EtOH) was investigated. Reaction kinetics were measured at T = 323 K and p = 1.01325 bar using in situ FTIR spectroscopy. Further, a thermodynamic activity-based kinetic approach was applied to predict the influences of NMP and LiCl on kinetics and equilibrium using ePC-SAFT advanced. The mole-fraction-based 'intrinsic' reaction-rate constants and the thermodynamic equilibrium constants were determined using the activity-based kinetic approach. These reaction constants allowed predicting the influences of the reactant ratio, NMP, and LiCl on homogeneity, reaction kinetics, and equilibrium in good agreement with the experimental data. The activity coefficients of the acid allowed understanding the experimental findings: they decreased upon NMP addition, which explains the slower reaction kinetics with NMP and they increased upon LiCl addition, which explains the faster kinetics with LiCl.