Challenges of Phosphate and Carbonate Salts as Catalysts for Biodiesel Synthesis

Influence of acid–base properties of Mg-based catalysts on transesterification: role of magnesium silicate hydrate formation

“…Phosphate is often used for transesterification with sodium or potassium as a counter-ion, which are leached in the reaction mixture. [11,12] When the counterion used is magnesium, the solubility of the solid is much smaller. Therefore, most of the catalysis carried out by these solids in those studies is eventually mostly done homogeneously by leached chemical species.…”

“…[9,10] Alkaline earth materials exhibit strong basic sites, but it has also been shown that other solids with weaker surface basicity are able to catalyze this reaction. For instance, biodiesel production can be achieved using potassium carbonate or phosphate, [11,12] barium hydroxide, [5] or zinc based materials [13,14] while calcium and barium acetate enable the transesterification of lactones. [15] Moreover, silicates are good catalysts for transesterification, used directly combined with magnesium [16] or as clay minerals, combined with aluminum, calcium and sodium.…”

Role of Water on the Activity of Magnesium Silicate for Transesterification Reactions

“…Catalysts with strong basic properties, such as calcium and magnesium oxides or zeolites, were reported to catalyze transesterification reactions. Additionally, some other solids with weaker surface basicity are also able to catalyze these reactions, that is, hydrotalcites, potassium carbonate or phosphate, barium hydroxide, or zinc based materials . In a previous publication, we worked on a model transesterification reaction, the conversion of ethyl acetate with methanol to compare the activities of a series of magnesium‐based catalysts in both liquid and gas phases.…”

The efficient and green synthesis of biodiesel from crude oil without degumming catalyzed by sodium carbonate supported MoS2

“…Britton et al employed silica and alumina as supports for the loading of phosphate and carbonate salts. 12 Martínez-Klimov et al supported sodium carbonate on sodium titanate nanotubes for the transesterification of soybean oil with methanol. 13 Although many works have focused on the transesterification of refined oil (degummed oil), less attention has been paid to the transesterification of phospholipids, which limits the application of alkaline salts in the production of biodiesel from crude oil (without degumming).…”