Efficient Catalytic Production of Biodiesel with Acid-Base Bifunctional Rod-Like Ca-B Oxides by the Sol-Gel Approach

Abstract

The search for acid-base bifunctional catalysts has become a hot topic in the preparation of biofuels from renewable resources. In the present work, a series of novel acid-base bifunctional metal-boron catalysts were successfully prepared by a sol-gel method and characterized by XRD, IR, SEM, TEM, TGA, BET, and TPD. Among those bifunctional solid materials, the Ca-B(700) catalyst had the highest density of both acid and base sites and showed excellent catalytic performance in the production of biodiesel from nonedible oils with high acid value. Under the optimal reaction conditions of 20/1 methanol/oil mole ratio and 4 wt % catalyst dosage at 105 °C for 2 h, a high biodiesel yield of 96.0% could be obtained from Jatropha curcas oil in one-pot. In addition, Ca-B(700) was also applicable to producing biodiesel from Firmiana platanifolia L.f. oil in a relatively low acid value, with an almost quantitative yield (98.5%) at 65 °C after 2 h. The Ca-B(700) catalyst had good stability and reusability, which is a promising acid-base bifunctional catalytic material for the preparation of biodiesel.

Supermagnetic Nano-Bifunctional Catalyst from Rice Husk: Synthesis, Characterization and Application for Conversion of Used Cooking Oil to Biodiesel

“…Briefly, 1 µm of prepared biodiesel sample was injected into the injection port; the GC oven temperature was fixed to increase from 100 • C-250 • C with 10 • C min −1 of the temperature ramp rate. The FAME yield (%) was measured using the formula stated below [11]:…”

“…Recently, the major drawbacks of homogeneous catalyst have been overcome by the development of heterogeneous catalyst which can be easily recovered from the reaction mixture by filtration, is recyclable, eco-friendly, and cuts off the need for neutralization which can reduce the cost of production [10]. Heterogeneous catalysts can be categorized into solid acid catalyst such as AC-Fe (5) -SO 3 Cl [3], SO 3 H-ZnAl 2 O 4 [11], Go-Fe 2 O 3 -SO 3 H [12] and basic solid catalyst, for example, Sr/MgO [13], MgO/MgAl 2 O 4 [14] and K 2 O-KCl alkaline catalyst [15]. Although heterogeneous catalysts have many advantages, the application of solid catalysts for transesterification reaction is still limited, owing to the low availability of active sites for the catalytic activity to occur [16].…”

Efficient Production of Methyl Oleate Using a Biomass-Based Solid Polymeric Catalyst with High Acid Density

“…Oleate. NMR 1 H spectroscopy is an e ective and simple method for quick detection of methyl oleate yields [29][30][31][32]. Generally, TMS is used as the internal standard marker for 0 point, and CDCl 3 is used as the solvent.…”

“…When the contact angle is greater than 90°, it is generally considered that catalyst has good hydrophobic properties. While the contact angle is between 30° and 90°, it is thought that the material has certain wettability, but the wettability is not good [8,29]. However, in the process of preparing methyl oleate, a certain contact angle can meet the needs of production.…”

Progress of Catalytic Valorization of Bio-Glycerol with Urea into Glycerol Carbonate as a Monomer for Polymeric Materials

“…It is worth noting that effective catalysis is usually demanded to generate monomers, to facilitate selective polymerizations and to enable recycling or upcycling of waste materials [13][14][15]. e increasing demands of biofuels and fuel additives, among which biodiesel has caused a considerable surplus of glycerol to the market that will create new threats in terms of their sustainable exploitation [16][17][18][19]. Stoichiometrically (Scheme 1), for the transesterification of triglycerides with methanol into biodiesel and glycerol, each tonne of biodiesel along with 100 kg of by-product crude glycerol are simultaneously generated [20,21].…”