No abstract

The esterification of valeric acid with n-butanol was studied with homogeneous and heterogeneous catalysts. The activity and performance of homogeneous ptoluenesulfonic acid and heterogeneous cation exchange resin catalysts Amberlyst 36, Indion 190, and Amberlite IRC-50 were evaluated. The pseudo-homogeneous kinetic model was used to investigate the kinetic parameters of homogeneous-and heterogeneous-catalyzed esterification. The UNIFAC (universal functional activity coefficient) approach was used to study the nonideality of the esterification reaction.The reaction was statistically modeled and optimized by the application of response surface methodology. The effects of independent variables such as reaction temperature, initial molar ratio, and catalyst loading on the conversion of valeric acid were investigated. The optimized conditions for the esterification reaction catalyzed by Amberlyst-36 were found as temperature 360.4 K, initial molar ratio 3.8, and catalyst loading 6.7 wt%. The predicted conversion (89%) at these optimized conditions is in good agreement with the experimental conversion (87.3 ± 1.6%). K E Y W O R D Sesterification, ion exchange resins, kinetics, p-toluenesulfonic acid, response surface methodology, UNI-FAC Int J Chem Kinet. 2018;50:710-725.wileyonlinelibrary.com/journal/kin

No abstract

Butyl butyrate was synthesized by esterification of butyric acid with n-butanol using homogeneous catalyst methanesulfonic acid (MSA). The esterification process was optimized by the application of response surface methodology (RSM) and artificial neural network (ANN). 3 level-4 variables central composite design (CCD) of RSM and MLP 4-9-1 network of ANN was chosen for the experimental design and analysis. The quadratic response model of RSM was optimized using desirability function approach. Effects of independent variables on the yield of butyl butyrate were investigated. Various training algorithm such as IBP, QP, GA, LM, BFGS, and CG was used for training experimental response data for the ANN study. By sensitivity analysis, the relative significance of 36.98 % confirmed that the molar ratio was the main affecting parameter on the yield of butyl butyrate. In prediction comparative study, ANN model was found better than the RSM model with high values of R2 (0.9998) and lower values of RMSE (0.2435), SEP (0.324 %), and AAD (0.0086 %) compared to RSM (R2=0.9862, RMSE=2.3095, SEP=3.076 %, AAD=0.6459 %). The accuracy of the RSM and ANN models were judged by validation test by performing unseen data experiments.

The liquid phase esterification of butyric acid with benzyl alcohol was studied using homogenous catalyst p-toluenesulfonic acid. The reversible second order rate equation was used to investigate the kinetic parameters of the reaction. The L9 orthogonal array of Taguchi methodology was employed to study the parametric effect independent variables on the responses equilibrium constant (Keq) and conversion (Xeq) of butyric acid. The parameters and their range such as catalyst concentration (0.5–1.5 wt%), temperature (333–363 K) and molar ratio (1–3) was used and considered as independent parameters for parametric sensitivity analysis. Non-ideal behavior of the reaction was studied using UNIFAC group contribution method. The effect of reaction temperature on the overall activity factor was studied. The relative parametric effect on the Keq and Xeq was found. In sensitivity analysis, temperature and molar ratio was the most influencing parameter on the Keq and Xeq. The regression model was developed and validate by performing unknown experiments.