Sodium zirconate (Na2ZrO3) as a catalyst in a soybean oil transesterification reaction for biodiesel production

Sodium zirconate (Na2ZrO3) was tested as a basic catalyst for the production of biodiesel using a soybean oil transesterification reaction. Initially, Na2ZrO3 was synthesized via a solid-state reaction. The structure and microstructure of the catalyst were characterized using X-ray diffraction, scanning electron microscopy and N-2 adsorption. Various transesterification reactions were then conducted using soybean oil and methanol under differing reaction conditions. The influence of some parameters, such as the reactant concentrations (molar ratios), catalyst percentage, reaction time, temperature and re-use of the catalyst, on the transesterification process in the presence of Na2ZrO3 was investigated. The maximum FAME conversion efficiency was 98.3% at 3 h of reaction time and 3% of catalyst. Additionally, the produced biodiesel was characterized using infrared spectroscopy, gas chromatography coupled to mass spectrometry and proton nuclear magnetic resonance. The resulting biodiesel showed good purity, composition and degree of unsaturation in comparison to previous reports. According to these results, Na2ZrO3 could become an alternative solid base catalyst for scalable and cost-effective biodiesel production. (C) 2013 Elsevier B.V. All rights reserved.