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Industrially important di‐carboxylic acids are synthesized from mono‐carboxylic unsaturated and unsaturated fatty acids. In this study, the aim is to perform the simultaneous catalytic oxidative C=C cleavage of oleic acid (OA) to azelaic acid and pelargonic acid, and oxidation of the terminal methyl group in pelargonic acid to azelaic acid using cobalt‐ and manganese‐acetate as catalyst, hydrogen bromide as co‐catalyst and air in acetic acid at elevated pressure (2.8–5.8 barg) and temperature (353–383 K). Oxygen solubility is determined under varying pressure, temperature and OA loading. The effect of OA loading, pressure and temperature on OA conversion and azelaic acid selectivity is studied by varying one variable at a time; however, the presence of the synergistic effect of the catalyst and co‐catalyst is investigated by central composite design assisted response surface methodology. Oxidation of terminal methyl group in saturated fatty acid is also confirmed by the oxidation of stearic acid to octadecanedioic acid using identical oxidation conditions of OA. Oxidation products of fatty acids are quantified by gas chromatographic analysis. The innovation of the work is thus the ability of the catalytic system to perform a total oxidation of a terminal methyl group of the hydrocarbon chain. OA oxidation kinetics relating to catalyst and co‐catalyst concentration along with oxygen solubility at elevated temperature and pressure is established. The frequency factor and activation energy for OA oxidation is determined using the Arrhenius equation.

Fresh and recycled bentonite nanoclay was used as a basic catalyst for the optimal synthesis of sal oil methyl ester biodiesel at high temperature. Bulk and surface properties of fresh and recycled catalyst were determined to check the recyclability. A catalyst concentration dependent lumped-parameter kinetic model was proposed for the transesterification of sal oil, and a simple genetic algorithm was used to determine the rate constants. Proposed rate constants were able to predict the experimental conversion of sal oil accurately under varying catalyst and methanol concentrations. A multiobjective optimization problem involving conflicting objectives (i.e., minimization of transesterification time, and minimization of undesirable intermediates) was formulated and solved using a nondominated sorting genetic algorithm. The temperature trajectory over the entire transesterification period was considered as a decision variable to obtain the fixed conversion of sal oil. A set of nondominated optimal Pareto solutions was obtained for the problem studied. For optimal synthesis, a higher isothermal temperature trajectory (≥503 K) was preferred for a short transesterification time (i.e., ≤35 min), whereas a nonisothermal temperature trajectory with lower reaction temperature (446.7–470.7 K) was required to keep undesirable intermediates at a minimum level (i.e., ≤0.0825 mol L–1) for 96.5% conversion of sal oil.

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