Application of ectoine as a co-solvent in esterification reactions in biodiesel synthesis Alfina Marwiyah, Rukman Hertadi
Chemistry, Faculty of Matemathics and Natural Sciences, Bandung Institute of Technology
Abstract
Biodiesel is an alternative fuel produced from renewable natural materials such as vegetable and animal oils, specially formulated for diesel engine fuel, with the advantages of high lubricating power, being environmentally friendly, safe, and non toxic. Biodiesel synthesis involves an esterification process with the help of a lipase enzyme catalyst. Lipase (triacylglycerol hydrolase) catalyzes the reaction of ester group formation to produce monoalkyl esters of fatty acids. The synthesis process requires a lipase that has stability against extreme conditions and organic solvents, especially alcohols. Ectoine is one of the osmolytes found in several types of halophilic bacteria that can protect proteins from heating, freezing, and chemical contact. This research will study the esterification activity with the addition of ectoine as a co solvent in the esterification reaction in biodiesel synthesis. Ectoine production from the halophilic bacteria Halomonas elongata BK AG25 was optimized by the osmotic shock technique grown on MM63 media. The bacteria were then inoculated on the same media with a high salt concentration (osmotic upshock) to produce ectoine and then transferred into distilled water with a low salt concentration (osmotic downshock) to release the ectoine produced. The ectoine obtained was then analyzed for its structure using NMR and HPLC. The success of ectoine as a lipase coprocessor was tested using the titration method to determine the esterification activity between oleic acid and ethanol in n hexane solvent by varying the concentration of ectoine used. Ectoine was successfully produced and was able to increase the esterification activity in the ratio of 2:1 to ethanol. Ectoine is also known to be able to maintain lipase stability at temperatures up to 50oC and at a more alkaline pH.
