Enabling Catalysts for Biodiesel Production via Transesterification

Abstract

With the rapid development of industry and the increasing demand for transportation, traditional sources of energy have been excessively consumed. Biodiesel as an alternative energy source has become a research focus. The most common method for biodiesel production is transesterification, in which lipid and low carbon alcohol are commonly used as raw materials, in the presence of a catalyst. In the process of transesterification, the performance of the catalyst is the key factor of the biodiesel yield. This paper reviews the recent research progress on homogeneous and heterogeneous catalysts in biodiesel production. The advantages and disadvantages of current homogeneous acid catalysts and homogeneous base catalysts are discussed, and heteropolyacid heterogeneous catalysts and biomass-derived base catalysts are described. The applications of the homogeneous and heterogeneous catalyst derivatives ionic liquids/deep eutectic solvents and nanocatalysts/magnetic catalysts in biodiesel production are reviewed. The mechanism and economic cost of current homogeneous acid catalysts and homogeneous base catalysts are also analyzed. The unique advantages of each type of catalyst are compared to better understand the microscopic details behind biodiesel. Finally, some challenges of current biodiesel catalysts are summarized, and future research directions are presented. This review will provide general and in-depth knowledge on the achievements, directions, and research priorities in developing novel homogeneous/heterogeneous catalysts for the green and cost-effective production of biodiesel.

Biodiesel Production from Waste Cooking Oil: A Perspective on Catalytic Processes

“…Nevertheless, it is also possible to find bio-based catalysts [204,205]. Additionally, it is precisely these catalysts based on biomass that have gained more attention in recent years due to their economic origin and because they are friendly to the environment [206].…”

Avocado Waste Biorefinery: Towards Sustainable Development

“…It is produced from vegetable oils such as soybean, canola, rapeseed, cottonseed, and maize, among others, and can also be obtained from animal fats or algae [12,48]. Biodiesel is a carbon-neutral fuel; this means that the amount of carbon produced by the combustion of biodiesel in engines is the same amount of carbon fixed by the plant during its growth [49]. The most common method for biodiesel production is the transesterification of triacylglycerides with alcohol [49,50].…”

“…Biodiesel is a carbon-neutral fuel; this means that the amount of carbon produced by the combustion of biodiesel in engines is the same amount of carbon fixed by the plant during its growth [49]. The most common method for biodiesel production is the transesterification of triacylglycerides with alcohol [49,50]. Despite the many advantages of biodiesel production from vegetable oils, this process has the disadvantage of using food as a feedstock source; therefore, the use of vegetable oil from non-food sources is preferable.…”

Biodiesel from Waste Cooking Oil: Highly Efficient Homogeneous Iron(III) Molecular Catalysts

“…Second, the reaction must be catalyzed to ensure adequate production rates. Although Brønsted's bases have undeniable good performance [11], their use is compromised or complicated by the presence of free fatty acids [12], whose concentration increases upon cooking [13]. For this reason, Lewis acid catalysts based on cheap metals have been proposed as an alternative, both homogeneous (e.g., complexes of Zn(II) [14][15][16][17], Sn(IV) [18,19] or Fe(III) [20]) or heterogeneous (metal oxides [21][22][23][24], their mixtures or salts) that simultaneously promote transesterification of triglycerides (Scheme 1) and esterification of free fatty acids (Scheme 2).…”