Show simple item record

dc.creatorLukić, Ivana
dc.creatorKesić, Željka
dc.creatorZdujić, Miodrag
dc.creatorSkala, Dejan
dc.description.abstractIncreased environmental concern and awareness of limited reserves of fossil fuels gave a great importance to alternative and renewable energy sources over the past couple decades. An excellent substitute for mineral diesel fuels is biodiesel, a mixture of fatty acid methyl esters (FAME), made by alcoholysis of different triacylglycerols (TAG) from various renewable sources (vegetable oils or animal fats) in the presence of a homogeneous or heterogeneous catalyst. Drawbacks of homogeneously catalyzed alcoholysis, to-day the most commonly used commercial biodiesel production process, have shifted the research focus on technologies based on utilization of solid catalyst. Heterogeneously catalyzed alcoholysis is more environmentally friendly, offers simplified production and improved process efficiency, allowing the possibility of catalyst’s regeneration, too. This technology of biodiesel synthesis is also the base for the continuous process development. Although great attention has been paid to the development of a catalyst that will have good activity and stability, followed by cheap method of synthesis, this task is still a challenge and needs further intensive research. Solid base catalysts have been characterized by high activity under mild reaction conditions and short reaction times, however, due to their sensitivity to the presence of impurities in the oil, primary the presence of free fatty acids (FFA) and water, they were not suitable, according to results of many investigations, for transesterification of lower-cost feedstock, such as non-edible plant oils and the waste cooking oils. For these feedstocks heterogeneous biodiesel synthesis should be performed applying solid acid catalyst. Despite the generally lower activity compared to solid base catalysts and higher reaction temperatures required for transesterification of oils into biodiesel, the main advantage of solid acids is their ability to simultaneously carry out esterification of FFA and transesterification of TAG. It is the main reason why application of solid acids for biodiesel production became a growing field of research during the last few years. In the present chapter, a comprehensive review of different solid acids used for biodiesel synthesis is presented. The method of catalyst preparation, type of precursor and employed calcination temperature greatly affect the acid catalyst activity and its final properties. The concentration of catalytic sites along with other characteristics, like surface area and catalyst porosity, are of great importance for catalytic activity of solid acids. The solid acids synthesis procedures and main catalyst’s characteristics are also analyzed in details, as well as the activity of solid acid catalysts in transesterification of different feedstock, with the emphasis on the lower-quality materials with high FFA content. One of the problems associated with heterogeneous catalysts is their deactivation with time due to poisoning, sintering or leaching of the active components, thus the attention in this review is also devoted to this issue. Furthermore, the transesterification process kinetics, being fundamental to reactor design and optimization of operational conditions in order to achieve maximum yield and lower cost of the process, is discussed.en
dc.sourceHeterogeneous Catalysts: Design, Applications and Research Insights
dc.subjectHeterogeneous catalysisen
dc.subjectSolid aciden
dc.titleSolid acids as catalysts for biodiesel synthesisen
dc.citation.other: 21-136

Files in this item


There are no files associated with this item.

This item appears in the following Collection(s)

Show simple item record