South African Journal of Chemical Engineering (Jan 2024)
Melon seed oil epoxidation: Kinetics and neuro-fuzzy evaluation
Abstract
Melon seed oil (MSO) is characterized by unsaturated triglycerides, making it a suitable candidate for epoxidation. This work explored the kinetic and Optimization of MSO epoxidation by the in-situ generation of peroxyacetic acid. The formation of the epoxide group was studied over the reaction time at various temperatures. With catalyst concentration, time, and temperature as the process variables and oxirane value as the response, Box Behnken design with Response Surface Methodology (RSM) was used to simulate and optimize the epoxidation process of MSO. The in situ epoxidation process obtained the highest oxirane of 3.4 and 3.45 % at 70 °C and 500 rpm with significantly less oxirane cleavage. The rate constants ranged from 0.0119 to 0.0341 lmol−1.s−1 for the temperature range of 50 to 90 °C. Thermodynamic parameters such as a change in enthalpy and entropy were calculated to be 22.21 KJ/mol and -32.744 cal.mol−1.K−1, respectively. The results of the ANOVA revealed a second-order polynomial model, with R2 values of 0.9996, Adj R2 (0.9992), and Pred R2(0.9944) of 0.9992 and 0.994, showing a high significance level between the experimental and predicted results. The 3D plots revealed that the process variables considerably impacted the oxirane value. The optimal oxirane value of 3.96348 % was obtained at a stirring speed of 597.821 rpm, a reaction time of 3.96348 h, reaction temperature of 71.7146 °C with a desirability of 1.000. Adaptive neuro-fuzzy inference system (ANFIS) optimum result with tri membership function gave an MSE of (1.99E-6), and the models demonstrated significant predictive behavior with R2 (0.9996) and (0.9653) for RSM and ANFIS, respectively. The FT-IR and physicochemical characterization of the MSO confirmed a high degree of unsaturated fatty triglycerides that were suitably epoxidized.; hence the novelty of this study dwells on the kinetics and ANFIS modeling of the MSO epoxidation process, which explains the reaction mechanism and non-linear behaviours of the epoxidation process.
