Modifications in the kinetics of transesterification of sunflower oil over strontium supported on silica by barium doping

Document Type : Original Article

Authors

Chemistry department, Faculty of Science, Ain Shams university 11566 Abbassia, Cairo, Egypt

Abstract

The effect of doping of strontium/silica (Sr40/ Si-Aocta) catalyst by barium on its kinetics of methanol transesterification of sunflower oil (MTSFO) to biodiesel was investigated. The experimental data of MTSFO over Sr40/Si-Aocta appear to be good fit into pseudo first order kinetic mechanism. However, the zero-order rate equation is the best fit model for MTSFO over BaSr40/Si-Aocta, compared with the pseudo-first order and second-order rate kinetic models. On the other hand, the intraparticle diffusion kinetics model may also play an important role in the MTSFO over BaSr40/Si-Aocta. In addition, a significant change was observed in Arrhenius activation energy of MTSFO over Sr40/Si-Aocta when it dopped by Ba. Where, Arrhenius activation energy values were found to be 16.6 and 49.6 kJ mol-1 for Sr40/Si-Aocta and BaSr40/Si-Aocta , respectively. These results can be suggested that addition of Ba toSr40/Si-Aocta can enhance its catalytic performance in selective MTSFO.
 

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