State of Art of Alkaline Earth Metal Oxides Catalysts Used in the Transesterification of Oils for Biodiesel Production

Abstract

Biodiesel produced through catalytic transesterification of triglycerides from edible and non-edible oils and alcohol is considered an alternative to traditional petro-diesel. The interest in the use of alkaline earth metal oxides as heterogeneous basic catalysts has increased due to their availability, non-toxicity, the capacity to be reused, low cost, and high concentration of surface basic sites that provide the activity. This work is a compilation of the strategies to understand the effect of the source, synthesis, and thermal treatment of MgO, CaO, SrO, and BaO on the improvement of the surface basic sites density and strength, the morphology of the solid structure, stability during reaction and reusability. These parameters are commonly modified or enhanced by mixing these oxides or with alkaline metals. Also, the improvement of the acid-base properties and to avoid the lixiviation of catalysts can be achieved by supporting the alkaline earth metal oxides on another oxide. Additionally, the effect of the most relevant operation conditions in oil transesterification reactions such as methanol to oil ratio, temperature, agitation method, pressure, and catalysts concentration are reviewed. This review attempts to elucidate the optimum parameters of reaction and their application in different oils.

Nano-architecture of CaO/Ag-chitosan nanocomposite by sol gel process: formation and characterization

“…To evolve the metalorganic composites as good platforms for various applications, alkaline metal oxides have been well purposed as organic linkers with metal-organic composites because of their excellent structural, catalytic, and antimicrobial activities. The alkaline earth metal oxides working for the various chemical reaction and transesterification reaction survey the mandate of their activity:-BaO, AgO, CaO, SrO, MgO; …etc [16][17][18][19]. Unique metal oxides either establish low activity and/or leaked out into the reaction combination to cause the uniform contribution in the catalytic activity [16].…”

“…The alkaline earth metal oxides working for the various chemical reaction and transesterification reaction survey the mandate of their activity:-BaO, AgO, CaO, SrO, MgO; …etc [16][17][18][19]. Unique metal oxides either establish low activity and/or leaked out into the reaction combination to cause the uniform contribution in the catalytic activity [16]. To improve both the reactivity well as stability, mixed metal oxides of various alkali earth Egyptian Journal of Chemistry http://ejchem.journals.ekb.eg/ ________________________________________________ Egypt.…”

“…12 (2021) oxides were synthesized and employed for the active chemical reactions. The active centers in the catalysts reactions are either oxide ion or permeated metal oxide or the different defects created because of metal impregnation [16]. Silver is probably considered the most noteworthy material in biological and plasmonics.…”

A study on the chemical profile and the derived health effects of heavy-duty machinery aerosol with a focus on the impact of alternative fuels

“…For RME, we found mainly alkali and alkaline earth metals showing the highest abundance compared to the elemental composition of PM 0.25 of B0 and GTL. The higher concentrations of alkali and alkaline earth metals in the PM of RME could be explained by their expected occurrence in natural sources such as rapeseed oil and by their common use as catalysts in the transesterification process of biofuels (Arzamendi et al 2008;Mohadesi et al 2014;Tavizón-Pozos et al 2021) (Arzamendi et al 2008). Recently, Tavizón-Pozos et al concluded that the combined use of alkaline earth oxides with alkaline metals might enhance their basicity so that more active sites would be available and a higher resistance to environmental factors could be achieved (Tavizón-Pozos et al 2021).…”

Trends in Widely Used Catalysts for Fatty Acid Methyl Esters (FAME) Production: A Review

“…Alkaline earth metals oxides such as Mg, Ba, Sr, Ca and Be, have been used for the production of biodiesel via the transesterification process [68].…”