Kinetic and Nonideal VLE Modeling for Transesterification Reactions from FFA and Methyl Acetate at High Temperature and Pressure Considering Volatilization Effects/Influence

Abstract

A model has been proposed considering the compounds’ volatilization influence in simultaneous nonideal phase equilibrium, reaction kinetics, and chemical equilibrium for batch transesterification reactions from free fatty acids at high pressure and temperature. Phase nonideality was modeled using the “φ – φ” method. Different kinetic and thermodynamic modeling approaches were applied and tested, and their parameters were estimated from the reaction data of oleic acid with methyl acetate catalyzed by niobium phosphate. Kinetic data at conditions of the liquid–vapor system were measured/obtained by varying the temperature, molar ratio, and initial reaction volume. The hypothesis of volatilization influence was evaluated and proved to be very relevant to ensure the model fitting, which its use proved necessary mainly for experiments with different initial ratios of the reaction volume/headspace or scale-up process. Auxiliary model hypotheses were evaluated. For the applied transesterification system, a study of volatilization influence was carried out and the simultaneous proposed model proved to fit data very well.