Non Catalytic Transesterification of Non-Edible, Edible and Waste Cooking Oils Under Super Critical Ethanol Conditions

In this comparative study, Camelina sativa oil (non-edible vegetable oil), Palm oil (edible vegetable oil) and Waste cooking oil were transesterified under supercritical ethanol conditions to produce high yields of Fatty Acid Ethyl Esters (FAEE).Hexane was used as a co-solvent, which helped to increase the mutual solubility of alcohol and vegetable oil and thus increased the yield of the biodiesel. Different process parameters like oil to alcohol molar ratio, reaction temperature, reaction time and the co-solvent ratio are optimized using Response Surface Methodology (RSM). This catalyst free process enables the transesterification of the oils to ethyl esters in short reaction times followed by simple separation and purification steps. The FAEE samples were analyzed using analytical instruments like FTIR and GC-MS. The thermal stability of final product was determined by Thermo Gravimetric Analysis (TGA). The fuel properties of biodiesel produced were compared with American Society for Testing and Materials (ASTM) standards for biodiesel.