Preparation of heterogeneous catalysts from limestone for transesterification of vegetable oils—Effects of binder addition

Calcium oxide as a promising heterogeneous catalyst for biodiesel production: Current state and perspectives

“…Packed-bed reactors are used in biodiesel synthesis from different oily feedstocks over various catalysts such as shell-core Ca (C 3 H 7 O 3 ) 2 /CaCO 3 [125], activated limestone [132], calcined quicklime [127], porous zirconia, titania and alumina [126], as well as anion-exchange [133,134] and cation-exchange [124,135] resins. The advantages of this reactor are flexibility and simple operation, prolonged use of catalysts, easy product separation from catalyst and continuous reaction mixture discharge from the reactor.…”

“…Calcium-based catalysts were used in packed-bed reactors in a few studies. Good ester yields were obtained in a simple packed-bed reactor filled with activated limestone-based catalysts (atomic ratio Ca:Mg:Al ¼4:3:1) using different oily feedstocks (bleached deodorized palm, food grade palm olein and waste cooking oils) and alcohols (methanol and ethanol) [132]. Continuous methanolysis of sunflower oil in a packed-bed tubular reactor with activated quicklime bits under optimal reaction conditions (methanol-to-oil molar ratio of 13.75:1, 333 K, residence time of 2 h) resulted in a yield of 98.6 71.1% within 30 h [127].…”

Calcium oxide based catalysts for biodiesel production: A review

“…Kawashima et al [29] prepared different kinds of mixed metal oxide catalysts using a simple physical mixing method, followed by calcination at high temperatures, while Ngamcharussrivichai et al [30] synthesized a series of catalysts through a wet mixing of ground limestone with different divalent and trivalent metal precursors, as binders, followed by drying and calcination.…”

Enhanced visible light-mediated photocatalysis, antibacterial functions and fabrication of a 3-chlorophenol sensor based on ternary Ag2O·SrO·CaO

“…8 Ag 2 O nanoparticles have been widely used in the eld of oxidation catalysis, 9,10 fuel cells, 11 sensors, 12 photovoltaic cells, 13 all-optical switching devices, and optical data storage systems 14 and as diagnostic biological probes. 15 CaO is an alkaline earth metal oxide and has many applications as a catalyst, 16 toxic-waste remediation agent, doped material to modify electrical and optical properties, 17 refractory additive, 18,19 and crucial component in CO 2 capture [20][21][22] as well as in ue gas desulfurization and pollutant emission control. 23 The purication of hot gases is possible by alkaline-earth oxides, mostly calcium and barium-based oxides.…”