Biodiesel is a direct substitute for petroleum derived fules and can be utilized in diesel equipment with few or no modication (Ma, Hanna, 1999). Traditional sources for biodiesel include plant oils (such as soybean or canola) that are also important food sources; biodiesel derived from plants might therefore not result in substantial
displacement of petroleum feedstocks. Algae may present itself as an alternate feedstock for biodiesel production that does not compete with the vital land and water resources needed for traditional agriculture. However, the production of fuels from algae is currently economically unviable due to several technological hurdles, including availability of efficient methods of converting cellular lipids to biodiesel.
The research described herein describes the in-situ transesterification of soy flour triglycerides (surrogate for algal biomass) with methanol to fatty acid methyl esters using a novel ionic liquid (IL) comprised of 1-Ethyl-3-methylimidazolium chloride (EMIMCl) and the metal halide AlCl3. This IL exhibits Lewis acidity and has been shown to be an excellent nonvolatile solvent and catalyst for many chemical reactions including acylations, condensations, esterications, and polymerizations. However, it is now proposed that this IL catalyst is able to perform esterication reactions with the addition of an organic solvent that solubilizes the ionic liquid yet allows it to retain its catalytic properties. This method enables the reaction to experience the benefits of homogeneous catalysis while providing an opportunity for catalyst recovery and reuse.
The influences of biomass concentration, catalyst volume, organic solvent/methanol ratios, reaction time, and temperature on the generation of the desired reaction products has been studied. A traditional mechanistic pathway to account for the observed production of fatty acid methyl esters is proposed and the triglyceride carbon mass balance is closed. The sustained catalytic ability of the ionic liquid was explored and the importance of ionic liquid recovery and reuse will be discussed. In addition, preliminary findings regarding the production of acrylates from biomass and Lewis acidic ionic liquids will be presented.