Preparation and application of Ce/ZrO2 - TiO2/SO42- as solid catalyst for the esterification of fatty acids

摘要

To develop heterogeneous and reusable catalyst for the esterification of fatty acids, in presence of tri-glycerides, sulfate species has been incorporated over Ce/ZrO2-TiO2 support. The catalyst activity was found to be a function of its Bronsted acidic sites which in turn depends on the cerium concentration in catalyst. The esterification of oleic acid with methanol or ethanol in presence of prepared catalyst has followed the first order kinetics and Koros-Nowak test has demonstrated that reaction rates are independent from diffusion limitations. An increase in acid or alcohol alkyl chain length (steric factor) was found to show negative effect on the esterification activity of catalyst. Although, the catalyst was able to catalyze the esterification even in presence of up to 12 wt% moisture (with respect to fatty acids), however, a decrease in turn over frequency (TOF) was observed. The catalyst has shown excellent stability as negligible sulfate leaching was observed and recovered catalyst was reused in five successive runs without significant loss in activity.