Spent groundnut oil for biodiesel production using supported heteropolyacids

Continuous use of petroleum sourced fuels is now widely recognized as unsustainable because of depleting supplies and contribution of these fuels to the accumulation of carbon dioxide in the environment. Renewable, carbon neutral, transport fuels are necessary for environmental and economic sustainability. Raw and spent vegetable oils have attracted attention as a potential renewable resource for the production of an alternative for petroleum-based diesel fuel. Supported heteropolyacids mainly Cesium Tungstophosphoric acid catalysts are an excellent alternate to the existing homogeneous catalysts for transesterification reaction in biodiesel production. CsTPA was supported externally and as a composite (internal and external) onto the support SBA15 and the parameters were optimized. It was found that the composite loaded catalyst system gave a maximum yield of 90.5% for 0.3% catalyst concentration, 6.6:1 methanol:oil molar ratio for 1 hour and 60°C. The methyl esters obtained from WCO were found to meet the ASTM standards for bio diesel. Performance characteristics of bio diesel with diesel were studied on a four stroke diesel engine under loaded conditions. Mechanical (67.79%), Brake and Indicated thermal efficiencies are better for biodiesel obtained from WCO than diesel (64.3%) thus making it a promising candidate as an alternate fuel.