Production of biodiesel as a renewable energy source from castor oil

The constantly increasing demand for energy can result in a huge crisis at the end of fossil fuels era. To prevent such an awkward situation, studies on finding alternatives have been seriously undertaken since the first oil crisis in the 1970s. Biodiesel, with a history of more than a century, has always been a potential candidate. In this research, the process of producing biodiesel from castor oil, which is a highly adaptable plant to Iran’s climates was studied. Methanol and castor oil as reactants with 10:1 molar ratio and sulfuric acid as catalyst with mass percent of 3 were allowed to react through trans-esterification reaction under mild conditions. The results from gas chromatography–mass spectrometry (GC–MS) showed the purity of more than 94 % esters for any conducted experiments which count as a success for an oil with more complicated structure than other raw vegetable oils. GPC analysis illustrated that the castor oil has a molecular weight of 1,068, which is almost three times that of colza oil. Some significant chemical and physical properties of the product, such as kinematic viscosity, flash point, pour point, etc. were calculated to approve conformity to ASTM D6751 standards. Eventually, the polluted emissions were measured by an Orsat gas analyzer. The outcomes completely corroborate the assumption which claims that adding biodiesel to conventional diesel fuels has a strong influence on lowering CO₂, CO, HC, and smoke.