Methyl Oleate Synthesis by TiO ₂ Photocatalytic Esterification of Oleic Acid: Optimisation by Response Surface Quadratic Methodology, Reaction Kinetics and Thermodynamics

Methyl oleate, an example of a FAME (fatty acid methyl ester), was produced by oleic (OA) photoesterification with TiO2 and UVA light. Different parameters were evaluated optimised: catalyst pretreatment, temperature (25–65 °C), loading (1–30 % w/wOA) : alcohol molar ratio (1 3–1 55). Response surface quadratic methodology obtained central composite rotational design (RSM-CCRD) used to evaluate the main operational conditions process. A high conversion 98 (±0.8) at 55 °C, 20 (w/wOA), 1(OA) 55(methanol) achieved. The mechanism is furthermore proposed. Langmuir-Hinshelwood kinetic model considered forward backward reaction as first-order fits best accuracy (R2 0.997). thermodynamic results (ΔG338.15K=−20.75 kJ/mol, ΔH=13.75 ΔS=0.47 kJ/mol.K) indicate that operating are important, both supply energy requirement reaction, but also increase miscibility reactants.