Oil transesterification

Transesterification has a number of important commercial uses. Methyl esters of fatty acids are produced from fats and oils. Transesterification is also the basis of recycling technology to break up poly(ethylene terephthalate) [25038-59-9] to monomer for reuse (29) (see Recycling, plastics). Because vinyl alcohol does not exist, poly(vinyl alcohol) [9002-89-5] is produced commercially by base-cataly2ed alcoholysis of poly(vinyl acetate) [9003-20-7] (see Vinyl polymers). An industrial example of acidolysis is the reaction of poly(vinyl acetate) with butyric acid to form poly(vinyl butyrate) [24991-31-9]. 

G.F. Ghesti, J. Lemos de Macedo, I.S. Resck, J.A. Dias and S.C.L. Dias, ET-Raman spectroscopy quantification of biodiesel in a progressive soybean oil transesterification reaction and its correlation with H NMR spectroscopy methods, Energ. Fuel, 21, 2475-2480 (2007). 

A byproduct of vegetable oil transesterification to make biodiesel fuel, glycerol (GO) has captured our attention for several reasons, in aqueous medium, GO itself can be converted to value-added commodity products such as propylene glycol (PG), lactic acid (LA) and ethylene glycol (EG) in the presence of a metal catalyst at mild conditions (2-7). An array of metals deposited on various supports have been examined as catalysts for the above reaction (6, 7). 

The effect of temperature on rapeseed oil transesterification reaction was investigated at 60, 45, and 30°C using the conditions of 1% (w/w), KOH as a catalyst and a methanokoil molar ratio of 6 1 (Fig. 2). Reaction equilibrium was reached within 10 min at each temperature studied. After 10 min of reaction, the conversion yields were 87.1,84.5, and 81.2% at 60,45, and 30°C, respectively. The conversion yield of rapeseed oil had only a small difference at lower temperatures. Freedman et al. (8) reported the effect of temperature on transesterification of refined soybean oil using a molar ratio of 1 6 and 1% NaOH. After 0.1 h, conversion yields were 94,87, and 64% at 60,45, and 32°C, respectively (8). Another study showed that the conversion of rapeseed oil at different temperature conditions (65,50, and 40°C) with an oiFMeOH molar ratio of 1 6, and 1.7% NaOH began at 40,20, and 5 min, respectively (9). This study used longer reaction times than our experiments. 

New Catalytic Systems for Vegetable Oil Transesterification Based on Tin Compounds... 

Tin oxide was tested as a catalyst for the soybean oil transesterification reaction (Abreu et al., 2005). Conversion of up to 56 % and 94.7 % were obtained, respectively, after one and five hours. At the end of the reaction it was possible to recover the catalyst by simple filtration of the mixture. The recovered solid was used three more times, under the same reaction conditions, and the catalytic activity was conserved. 

This book is composed of 32 chapters divided into three sections. The first 10 chapters describe the world s newest biodiesel research. Included is biodiesel research at NCAUR, USDA, production of biodiesel fuel through bioprocesses, a biodiesel cost optimizer-least cost raw material blending for standard quality biodiesel, new catalytic systems for vegetable oil transesterification... 

It is worth noting that differences in acid strength between anhydrous Keggin heteropolyacids (H3PW12O40 > H4SiWi2O40 > H3PM012O40 > H4SiMoi204o) measured by ammonia adsorption calorimetry did not correlate simply with the catalytic activity in the reaction of rapeseed oil transesterification with methanol and ethanol [102]. 

An alternative to the integrated processing of oilseeds and seed-oil transesterification is to purchase the oils on the open market and transform them into biodiesel. This eliminates the by-product meal, simplifies the process, and lowers the capital and operating costs. In this case, the principal economic barrier in the United States is the direct purchase cost of 0.53 to S0.79/L ( 2 to 3/gal) for triglyceride oils. This is acceptable in certain European regions... 

Fats/oils Transesterification hydrolysis Cocoa butter, margarine fatty acids, mono diglycerides... 

Abreu, F.R. M.B. Alves C.C.S. Macedo L.F. Zara P.A.Z. Suarez. New multi-phase catalytic systems based on tin compounds active for vegetable oil transesterification reaction. J. Mol. Catal. A Chemical 2005,227, 263—267. 

Encinar, J.M. J.F. Gonzalez J.J. Rodriguez A. Tejedor. Biodiesel fuels from vegetable oils transesterification of cynara cardunculus 1. oils with ethanol. Energy dr FueL 2002, 16, 443—450. 

Apart form wine and juices the method has been successfully applied to issues such as the authentication of sugars of various origins, origin of glycerol (sugar fermentation versus edible oil transesterification),... 

The conversion of microalgae to fuels takes the following steps harvesting, dewatering, extraction and oil transesterification. 

Biodiesel production using the biocatalyst lipase avoids the disadvantages of the alkaline process without the need for subsequent wastewater treatment (Taher et al., 2011). Additionally, lipases can operate in mild conditions with a high substrate selectivity. M. miehei, R. oryzae, C. antarctica, and P. cepacia are all common lipases found to be capable of catalyzing oil transesterification in order to produce biodiesel. 

Noncatalytic Vegetable Oils Transesterification Using Supercritical Alcohols for Biodiesel Production... 

Numerous studies have reported that pretreatment of an immobilized lipase affects its activity and stability. Samukawa et al. (2000) studied the effect of Novozym 435 preincubation in methyl oleate on soybean oil transesterification with methanol. Immobilized lipase was incubated in methyl oleate for 0.5 h and then in the oil for 12 h. The use of an incubated enzyme resulted in a 20% higher yield in 1 h, compared to only 13.6% achieved by the nonincubated enzyme. The stability of immobilized lipase was also enhanced by incubation in tert-butanol. The high catalytic activity and stability of the incubated immobilized lipase have been confirmed by several researchers (Li et al., 2006 Royon et al., 2007). The positive effect might be due to terf-butanol s ability to shield the enzyme from being inhibited by methanol or by immersion in tert-butanol. 

Peterson, G., and W. Scarrah. 1984. Rapeseed Oil Transesterification by Heterogeneous Catalysis. Journal of the American Chemical Society 61 (10) 1593-1597. 

FIGURE 12.4 Experimental and simulated concentrations during mustard oil transesterification at 60°C (a) triglyceride concentration (b) diglyceride concentration (c) monoglyceride concentration (d) methyl ester concentration (e) glycerol concentration (f) methanol concentration. 

Encinar, J. M., Gonzalez, J. F., Pardal, A., and Martinez, G. Rape oil transesterification over heterogeneous catalysts. Fuel Processing Technol 91,1530-1536 (2010). 

Yang, Z., and Xie, W. Soybean oil transesterification over zinc oxide modified with alkali earth metals. Fuel Processing Technol 88,631-638 (2007). 

Damoko, D., Cheryan, M., 2000. Kinetics of palm oil transesterification in a batch reactor. Journal of the American Oil Chemists Society 77 (12), 1263—1267. 

Micic, R.D., Kiralj, M.S.B., et al., 2015. Activation temperature imposed textural and surface synergism of CaO catalyst for sunfiower oil transesterification. Fuel 159, 638—645. 

Madhuvilakku, R., Piraman, S., 2013. Biodiesel synthesis by Ti02—ZnO mixed oxide nanocatalyst catalyzed palm oil transesterification process. Bioresource Technology 150, 55—59. Available at http //www.sciencedirect.com/science/article/pii/S096085241 3015198 (accessed 22.06.14.). 

Xie, W., Wang, T., 2013. Biodiesel production from soybean oil transesterification using tin oxide-supported WO3 catalysts. Fuel Processing Technology 109, 150—155. Available at http //www.scienceditect.eom/science/article/pii/S0378382012003797 (accessed 11.05.15.). 

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