Andinet Ejigu

Moringa stenopetala seed oil as a potential feedstock for biodiesel production in Ethiopia

Moringa stenopetala seed oil was evaluated as a potential sustainable feedstock for biodiesel production in Ethiopia. Base catalyzed transesterification of M. stenopetala seed oil was carried out with methanol, ethanol and a mixture of methanol and ethanol (1:1 molar ratios) with an alcohol to oil molar ratio of 6:1. The physiochemical characteristics of the esters were assessed to evaluate their suitability for use in standard diesel engines. The study indicated that M. stenopetala seeds yield 45% w/w of oil. The oil contains 78% mono-unsaturated fatty acid and 22% saturated fatty acid. Oleic is the dominant fatty acid, about 76%. When mixtures of alcohols were used, the amount of ethyl ester formed was 30% that of methyl ester. The physicochemical properties of M. stenopetala oil methyl ester and mixture of esters (methyl and ethyl) were found to comply with both the American ASTM D6751 and the European standard EN 14214. Overall, the physicochemical properties of the ester mixture of M. stenopetala oil were better than that of methyl ester. The recommended way to use the oil as a fuel is as a mixture of esters. The study indicates that compared to biodiesel fuels derived from other vegetable oils, M. stenopetala has a number of advantages. Furthermore, the use of M. stenopetala seed oil for the production of biodiesel will not compete with food as neither the seeds nor the oil are used for food in Ethiopia.

Electrocatalysis in Room Temperature Ionic Liquids

Electrocatalytic reactions are those in which the reaction rate is sensitive to the nature of the electrode material. Such reactions, which include the oxygen reduction reaction (ORR), hydrogen oxidation reaction (HOR), and hydrogen evolution reaction (HER), often play key roles in electrochemical energy conversion and have been studied for decades, primarily using aqueous electrolytes. In recent years, the study of electrocatalytic reactions has extended to room temperature ionic liquid (RTIL)-based systems. In many cases, these developments have been driven by a desire to fabricate new RTIL-based fuel cells and batteries that can operate at higher temperatures, or are safer, than conventional systems. Other studies have focussed on the fundamental electrocatalytic processes at play in RTILs. In this chapter, we provide an overview of the work that has been done in this area to date with a particular emphasis on processes relevant to electrochemical energy conversion. The chapter begins with an introduction, in which the rationale for performing electrocatalytic measurements in RTILs is described. As much of the work done in this area has been carried out in protic ionic liquids (PILs), a brief description of PIL chemistry is then given. This is then followed by a discussion of the electrocatalytic work that has been performed to date. As we will see, the insights obtained from this work impact not only on fundamental electrochemistry and electrocatalysis in the broader sense, but may also impact on next-generation energy-conversion technologies.