Transesterification of Degummed Jatropha curcas Oil Using Tri-potassium Phosphate as Base Catalyst

oil and methanol are transesterified using potassium triphosphate as base catalyst. The effects of methanol to oil molar ratio, reaction temperature, stirring speed, catalyst concentration, solubility and its reusability on the yield of biodiesel are investigated. The base catalyst tri-potassium phosphate (K PO ) is found to be highly suitable for oils having less than 1.5% free fatty acids (FFA). Highest biodiesel yield (approximately 92%) is acquired under optimum conditions of 9:1 methanol to oil molar ratio, 2% catalyst at 70°C reaction temperature at a stirring speed of 650 rpm. The chemical activity of K PO is found to be similar to that of base catalyst potassium hydroxide (KOH) and the catalyst solubility in biodiesel as determined by atomic absorption spectra is only 4.81 ppm. It has been found that K PO is highly hygroscopic and its reusability drastically decreases upon further usage and it can be reused only in wetted condition for three continuous usages with drastic reduction in catalytic strength. The biodiesel samples prepared were tested for several physicochemical properties and compared with the values of European biodiesel standards. The fatty acid methyl esters (FAME), also referred to as jatropha methyl esters (JME) in this paper, have been analyzed by gas chromatography and thermogravimetric analysis.