Esterification of Fatty Acids Using a Bismuth-Containing Solid Acid Catalyst

Abstract

The conversion of lauric acid and fatty acid mixtures to methyl esters was investigated using bismuth-containing solid catalysts obtained from Bi 2 O 3 . When the reaction was carried out at 140 °C for 2 h using a methanol:fatty acid molar ratio of 2:1 and 5 wt % of Bi 2 O 3 in relation to the mass of fatty acids, conversions up to 87 wt % were achieved even after four consecutive reaction cycles. Besides the observed catalytic activity, the bismuth-containing solid catalyst was also amenable to recycling for at least four reaction cycles without significant loss of its catalytic performance. However, the analysis of the recovered solids by X-ray diffraction and Fourier transform infrared spectroscopy demonstrated that Bi 2 O 3 was converted to layered bismuth carboxylates, which acted as the actual esterification catalyst. On the basis of these, layered bismuth carboxylates unfold as a suitable catalytic system for the esterification of fatty acids and lipid sources of high acid number.

Fabrication of a Bi2O3 Surface-Modified Polyvinylidene Fluoride Membrane via an Ultraviolet Photografting Method: Improving Hydrophilicity and Degree of Acrylic Acid Grafting

“…As displayed in Figure , with the addition of TBA, the degree of AA grafting increases slightly in comparison to no scavenger added membrane. This phenomenon may be caused by esterification of acrylic monomers with alcohols . In addition, in this Bi 2 O 3 photocatalytic system, no hydroxyl radicals were identified through EPR spectra (Figure S3 in the Supporting Information) because holes photogenerated on the photocatalyst surface could not react with H 2 O to produce • OH.…”

“…This phenomenon may be caused by esterification of acrylic monomers with alcohols. 30 In addition, in this Bi 2 O 3 photocatalytic system, no hydroxyl radicals were identified through EPR spectra (Figure S3 in the Supporting Information) because holes photogenerated on the photocatalyst surface could not react with H 2 O to produce • OH. This result may be attributed to the lesser standard redox potential of Bi 5 + /Bi 3 + (E 0 = 1.59 V at pH 0) compared to • OH/OH − (E 0 = 1.99 V at pH 0).…”

Reusable Heterogeneous Tungstophosphoric Acid-Derived Catalyst for Green Esterification of Carboxylic Acids

“…In this respect, acidic solids have been investigated as heterogeneous catalysts. 12,13 A wide range of solid acids has already been explored in esterification reaction including chalcogenides, 14 acid clays, 15,16 oxides, 10,17,18 modified silica, 19,20 polymers, 21 and activated carbon. 22−24 Heteropolyacids (HPAs) have been effectively employed to catalyze the esterification of free fatty acids (FFAs).…”

“…Green synthetic approaches to prepare esters and overcome the present drawbacks have received much attention. In this respect, acidic solids have been investigated as heterogeneous catalysts. , A wide range of solid acids has already been explored in esterification reaction including chalcogenides, acid clays, , oxides, ,, modified silica, , polymers, and activated carbon. − Heteropolyacids (HPAs) have been effectively employed to catalyze the esterification of free fatty acids (FFAs). − These extremely acidic compounds are anionic metal–oxygen clusters based on polyoxometalates (POMs) . The HPAs are environmentally friendly alternatives to the use of mineral acids (H 2 SO 4 , HCl, or HF) .…”

Analysis of recycled poly (styrene-co-butadiene) sulfonation: a new approach in solid catalysts for biodiesel production

“…Solid-acid catalysts, such as Dowex monosphere 550A, Dowex upcore Mono A-625, Amberlyst-15, Amberlyst-16, Amberlyst-35, Dowex HCR-W2, mesoporous aluminosilicates, Amberlyst 131, Relite CFS, ZrO 2 -supported metal oxide and mesoporous organosilicas, have also been considered (Özbay et al 2008, Carmo et al 2009, Tesser et al 2010, Morales et al 2010, Kim et al 2011). More recently layered bismuth carboxylates, has also been used in esterification of fatty acids (Rosa da Silva et al 2013). Compared with sulfuric acid, solid-acid catalysts have lower reaction rates, but they are often preferred over sulfuric acid because they are easily separated from the product, prevent corrosion (Silva and Rodrigues 2006) and can be reused (Vieira Grossi et al 2010).…”