Esterification of oleic acid with ZrO2/SO42-@MIL-101(Cr) catalyst for biodiesel production

Biodiesel production is one of the promising ways of saving fossil fuels as it’s a renewable and environmentally friendly source of energy which can be produced domestically [1]. In addition to lowering the risk of global warming, biofuel can lead the world to a stable economy while reducing health problems [2]. Esterification and transesterification are two consecutive reactions that can produce FAME or biodiesel from FFA content of edible and non-edible oils such as vegetable oils, animal fats, Karanja, jatropha, and even waste cooking oil. The most common alcohol that is used widely for this process is methanol, which is a short chain and polar and it’s relatively cheaper than other alcohols [1]. Esterification is a reversible reaction and it’s catalyzed by different kind of homogenous and heterogeneous catalysts. This study aims to present a composite as a solid acid catalyst. MIL-101(Cr) is used as a support for sulfated zirconia in order to improve the %FFA Conversion and also to prevent leaching of sulfate groups. Different factors such as temperature, time, oil to methanol molar ratio, the concentration of catalyst that affect this reaction have been observed and the optimum condition is provided. MIL-101(Cr) and ZrO2/SO42- have shown less catalytic activity compared to synthesized composite under atmospheric pressure. No significant reduction in catalyst activity is seen up to the third cycle.