Clean and efficient production of biodiesel using barium cerate as a heterogeneous catalyst for the biodiesel production; kinetics and thermodynamic study

Barium cerate, a novel solid base catalyst was employed in transesterification reaction for biodiesel production. The catalyst was characterized by Thermogravimetric analyses, powder X-ray Diffraction, Scanning Electron Microscopy attached with energy dispersive unit, Fourier Transform Infrared Spectroscopy. Karanja oil was used as non-edible feedstock for biodiesel production. The fatty acid profile of feedstock was analyzed by Gas Chromatography-Mass Spectrometry. In the present study, calcination temperature was optimized for synthesis of perovskite barium cerate with highest phase purity. Additionally, various Ba/Ce stoichiometric ratios were also checked to evaluate the active metal phase of catalyst. Ultimately, perovskite structure with 1:1 Ba/Ce was found to be most efficient one to catalyze the transesterification. This owed to the higher basicity value as well as compact and well-arranged perovskite crystal system which facilitate the catalysis on its surface. It produced the karanja oil methyl ester with 98.4% conversion at following experimental conditions: catalyst dose (1.2 wt %), oil to methanol molar ratio (1:19), reaction temperature (65 degrees C), reaction time (100min), and agitation speed (600 rpm). The pseudo-first order kinetic model was also successfully established for transesterification reaction. Green chemistry metrics (E-factor) and turn over frequency were also evaluated for methanolysis reaction. Barium cerate exhibited sixth cycle reusability with 81% methyl ester conversion. Therefore the prepared catalyst was ascertained as a sustainable heterogeneous catalyst for transesterification reaction. The physicochemical properties of the synthesized karanja oil methyl ester were measured according to ASTM D 6751 and were found to be within the permissible range. It ensured the compatibility of produced biodiesel with existing CI engines without any further modification. (C) 2019 Elsevier Ltd. All rights reserved.