Highly Efficient and Recyclable Metal Salt Catalyst for the Production of Biodiesel: Toward Greener Process

Abstract

A highly reactive and recyclable metal catalyst was reported for the transesterification of model vegetable oil with methanol to produce fatty acid methyl esters (FAMEs) under microwave condition. Among the screened catalysts, Al2(SO4)3 provided the highest FAME yield of 98.1 % at 130 oC within 30 min. Different reaction parameters were fully investigated which were found to have great influences on the product yields. Microwave energy showed a remarkable accelerated reaction rate as compared to that from the conventional oil heating way. The catalytic system also showed good tolerance to water and free fatty acids. The catalyst can be easily recovered through a simple extraction/evaporation, which still posed good reactivity in the recycling runs. The characters of the obtained biodiesel was also characterized. Mechanistic studies revealed that the hydrolysis of the metal salt to generate the corresponding cationic and acidic species were responsible for the good catalytic activity of the reaction.

Insight into Aluminum Sulfate‐Catalyzed Xylan Conversion into Furfural in a γ‐Valerolactone/Water Biphasic Solvent under Microwave Conditions

“…As presented in Figure , a sharp peak at 0.5 ppm was observed immediately after the introduction of Al 2 (SO 4 ) 3 to the D 2 O solvent, which was assigned to the formation of hexa‐coordinated Al species . Furthermore, a weak resonance peak at −2.8 ppm was also observed, which was attributed to the partial coordination of SO 4 2− instead of D 2 O, which shielded the Al center . As the hydrolysis reaction proceeded, the resonance peak center at 0.5 ppm remained unchanged, which indicated that the Al center was in the hexa‐coordinated form throughout the reaction.…”

Highly Active MgP Catalyst for Biodiesel Production and Polyethylene Terephthalate Depolymerization

“…For the biodiesel production some heterogeneous catalysts have been tested, [7–9] and the alkaline metal oxides like BaO, CaO, MgO, and SrO have proven to be efficient due to their basicity, low activation temperature, and shorter reaction times [10,11] . From these groups of metal oxides, magnesium oxide has attracted the attention of the scientific community, due to its considerable basicity, stability, and not dissolution in the reaction medium [12,13] …”

“…[5] In this respect, biodiesel can be used as a green replacement for Petro diesel due to its low sulfur content, no harmful aromatics, improved combustion (10-11 % of oxygen content), higher flash point, inherent lubricity, and reduced carbon dioxide emissions. [6] For the biodiesel production some heterogeneous catalysts have been tested, [7][8][9] and the alkaline metal oxides like BaO, CaO, MgO, and SrO have proven to be efficient due to their basicity, low activation temperature, and shorter reaction times. [10,11] From these groups of metal oxides, magnesium oxide has attracted the attention of the scientific community, due to its considerable basicity, stability, and not dissolution in the reaction medium.…”

Microwave‐mediated noncatalytic synthesis of ethyl levulinate: A green process for fuel additive production

“…30,32 Because of these benefits, MW could be a potential technique for promoting esterification reactions. 33 Although MW has been extensively used as an assisted technique in catalytic organic synthesis, [34][35][36][37][38] no study has reported its use in the noncatalytic esterification of levulinic acid. Noncatalytic levulinic acid esterification with ethanol using MW can facilitate an energy-efficient and ecofriendly process for preparing ethyl levulinate.…”