(63e) Biodiesel Synthesis, Characterizaton and Emissions Testing Using Chromatographic Methods

Biodiesel, also known as fatty acid alkyl esters, which is derived from triglycerides by transesterification with an alcohol, has attracted considerable attention during the past decade as a biodegradable, non-toxic fuel. Because of its environmental benefits and the fact that it can be used in any diesel engine without modification, biodiesel is technically competitive and offers advantages compared to conventional petroleum diesel fuel. Besides being a renewable resource, biodiesel reduces polycyclic aromatic hydrocarbons while engine performance and fuel economy are nearly identical to those of conventional fuels. Several processes have been developed, among which transesterification using alkali-catalysis gave high levels of conversion of triglycerides to their corresponding methyl esters in a short reaction time.

Transesterification of four commercial grade vegetable oils: canola oil, corn oil, peanut oil, and soybean oil, was carried out using methanol and three catalysts: sodium hydroxide (NaOH (s) pellets), liquid sodium hydroxide (1 N NaOH (l) and sodium methoxide (NaOCH3 (s)) as catalysts. The methyl esters of the corresponding oils were separated from the glycerol by-product, purified, and characterized by different methods to evaluate their densities, yields, and composition. From the qualitative analyses performed, it was determined that based on density, yield, and emissions testing, corn biodiesel had most potential for being an alternative for diesel fuel.