Three acid zeolites (H-ZSM-5, H-Beta, and H-FER) were evaluated in the oleic acid isomerization to branched-chain fatty acids (bc-FA). Understanding its kinetic behavior is essential to develop new technologies regarding biofuels, lubricants, and cosmetics. The catalysts were characterized through XRD, N2 physisorption, and NH3-TPD. Preliminary reactions demonstrated that Ferrierite shows better yields in the reaction, which is associated with its higher Brønsted acidity. Optimal reaction pressure and time were 10 bar and 10 h, respectively. A full factorial design of experiments was used to evaluate the reaction temperature and the use of the cocatalysts, water and triphenylphosphine (TPP). The maximum yield (59%) was achieved using 8% of water and 10% of TPP at 300 °C. A reaction mechanism in which the oleic acid turns into its trans isomer before bc-FA formation was proposed, and the kinetic modeling of the process was carried out with reproducible results.

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