Determination of the kinetics of biodiesel saponification in alcoholic hydroxide solutions

Eze, Valentine C.; Harvey, Adam P.; Phan, Anh N.

doi:10.1016/j.fuel.2014.10.001

Cited by 41 publications

(13 citation statements)

References 24 publications

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“…The results showed that, there were numerous floccules floating on the top of the reaction mixture when using 2 mL of methanol, while a clear homogeneous solution was obtained when using 2 mL of ethanol. It was reported that the saponification rate of fatty acid methyl esters in ethanol/hydroxide was higher than that in methanol/hydroxide, whether in the presence of water or not . This was probably due to the lower acidity of ethanol, leading to a higher concentration of hydroxide ions in the ethanol/hydroxide solutions, thus accelerating saponification reaction .…”

Section: Resultsmentioning

confidence: 99%

“…It has been reported that saponification is a bimolecular reaction: hydroxide ions attack the carbonyl of the ester, and protic solvents such as water or simple alcohols provide hydrogen bonding, resulting in the formation of the stable tetrahedral intermediate, which then decomposes to products [23]. In previous reports, the saponification reaction of oils is conducted in alcoholic alkali to increase the reaction rate [16,17]; it not only consumes a large volume of organic solvents but also impacts the application of microextraction in the subsequent step.…”

Section: Saponification Conditionsmentioning

confidence: 99%

“…It was reported that the saponification rate of fatty acid methyl esters in ethanol/hydroxide was higher than that in methanol/hydroxide, whether in the presence of water or not [23]. This was probably due to the lower acidity of ethanol, leading to a higher concentration of hydroxide ions in the ethanol/hydroxide solutions, thus accelerating saponification reaction [23]. The effect of the ethanol volume was then evaluated.…”

Section: Saponification Conditionsmentioning

confidence: 99%

See 2 more Smart Citations

Determination of benzo[a]pyrene in edible oils using phase‐transfer‐catalyst‐assisted saponification and supramolecular solvent microextraction coupled to HPLC with fluorescence detection

Wang

Liu

Shi

et al. 2016

J of Separation Science

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For the analysis of edible oils, saponification is well known as a useful method for eliminating oil matrices. The conventional approach is conducted with alcoholic alkali; it consumes a large volume of organic solvents and impedes the retrieval of analytes by microextraction. In this study, a low-organic-solvent-consuming method has been developed for the analysis of benzo[a]pyrene in edible oils by high-performance liquid chromatography with fluorescence detection. Sample treatment involves aqueous alkaline saponification, assisted by a phase-transfer catalyst, and selective in situ extraction of the analyte with a supramolecular solvent. Comparison of the chromatograms of the oil extracts obtained by different microextraction methods showed that the supramolecular solvent has a better clean-up effect for the unsaponifiable matter from oil matrices. The method offered excellent linearity over a range of 0.03- 5.0 ng mL (r > 0.999). Recovery rates varied from 94 to 102% (RSDs <5.0%). The detection limit and quantification limit were 0.06 and 0.19 μg kg , respectively. The proposed method was applied for the analysis of 52 edible oils collected online in China; the analyte contents of 23 tested oil samples exceeded the maximum limit of 2 μg kg for benzo[a]pyrene set by the Commission Regulation of the European Union.

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Section: Resultsmentioning

confidence: 99%

Section: Saponification Conditionsmentioning

confidence: 99%

Section: Saponification Conditionsmentioning

confidence: 99%

See 1 more Smart Citation

Determination of benzo[a]pyrene in edible oils using phase‐transfer‐catalyst‐assisted saponification and supramolecular solvent microextraction coupled to HPLC with fluorescence detection

Wang

Liu

Shi

et al. 2016

J of Separation Science

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“…Correspondingly, there were free carboxyl, residual carboxyl, unilateral ester, and bilateral ester groups in the PVA membrane. The carboxyl group could be neutralized by aqueous NaHCO 3 , Na 2 CO 3 , and NaOH solutions, whereas the ester group could only be saponified by an aqueous NaOH solution . As a result, the content of carboxyl groups and the content of ester groups in the PVA membrane could be obtained by acid–base titration.…”

Section: Resultsmentioning

confidence: 99%

Experimental investigation of the effects of crosslinking processes on the swelling and hygroscopic performances of a poly(vinyl alcohol) membrane

Gao

Wang

et al. 2016

J of Applied Polymer Sci

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Poly(vinyl alcohol) (PVA) membranes crosslinked with L-malic acid were prepared, and the effects of the heat-treatment temperature and crosslinker concentration on their swelling and hygroscopic performances were investigated. Both the swelling and hygroscopic performances of the PVA membranes decreased with increasing heat-treatment temperature; while the former decreased, the latter increased with increasing crosslinker concentration. The PVA membranes were characterized with differential scanning calorimetry (DSC), acid-base titration, and Fourier transform infrared spectrometry. The DSC results indicated that there was freezing and nonfreezing water in the swollen membranes, whereas there was only nonfreezing water in the moistened membranes. In addition, acid-base titration analysis revealed that both increased heat-treatment temperature and increased crosslinker concentration increased the bilateral ester group levels (crosslinking degree) and decreased the content of freezing water. By contrast, the content of hydrophilic groups decreased and increased with increasing heat-treatment temperature and crosslinker concentration, respectively; this resulted in decreased and increased levels of nonfreezing water, respectively.

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“…Compared to the methanolysis, ethanolysis produces fatty acids ethyl esters (FAEE) and the obtained solutions have a larger miscibility region of the reaction products [3]. Even low water amounts in EtOH produces highly stable emulsions due to more content of soaps formed during the reaction [4]. Membrane technology can be used to ensure an efficient and sustainable way to purify BD made from ethanol.…”

Section: Introductionmentioning

confidence: 99%

Application of a composite ultrafiltration membrane for biodiesel purification

et al. 2018

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This study was carried out to investigate the potentialities of the application of membrane technology in biodiesel purification without need of the decantation step. A new composite UF membrane was prepared from poly(vinylidene fluoride) casting solution (17 wt%) containing a sulfonated Carbon (20 wt%). The assays were performed in a dead-end filtration cell with synthetic mixtures of the transesterification reaction products. The influence of two operational variables was analyzed, transmembrane pressure (ΔP = 4-8 bar) and temperature (T = 50-60°C). The membrane performance was evaluated determining the flux and the permeate compositions. Temperature resulted to be the most important operational variable. An increase in 10°C duplicated the permeate flux at 6 and 8 bar. The best performance was obtained at 60°C and 8 bar, with a flux of 12.6 Lm-2 h-1. In this operative conditions, the influence of the added acidified water (W add = 0-20 %v/v) in the synthetic mixture was evaluated, which increased considerably permeate fluxes. Finally, the impact of synthetic mixture composition was determined for the assayed best operational conditions. The higher flux value was measured in the mixture with less glycerol and without soaps. In all assays the biodiesel retention was complete and the permeates were composed mainly of glycerol and ethanol.

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Determination of the kinetics of biodiesel saponification in alcoholic hydroxide solutions

Cited by 41 publications

References 24 publications

Determination of benzo[a]pyrene in edible oils using phase‐transfer‐catalyst‐assisted saponification and supramolecular solvent microextraction coupled to HPLC with fluorescence detection

Determination of benzo[a]pyrene in edible oils using phase‐transfer‐catalyst‐assisted saponification and supramolecular solvent microextraction coupled to HPLC with fluorescence detection

Experimental investigation of the effects of crosslinking processes on the swelling and hygroscopic performances of a poly(vinyl alcohol) membrane

Application of a composite ultrafiltration membrane for biodiesel purification

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