Esterification oleic acid

The esterification of -butyl alcohol and oleic acid with a phenol—formaldehydesulfonic acid resin (similar to amberHte IR-100) is essentially second order after an initial slow period (52). The velocity constant is directiy proportional to the surface area of the catalyst per unit weight of reactants. 

Microemulsion media can be adopted for biotransformations lipases have been used and large difference in rates of esterification, e.g. I-pentanol vs 2-pentanol with oleic acid, have been observed (Stamatis et al., 1993). 

Lipase from Aspergillus niger Esterification of 1-butanol and oleic acid Oil-deionized water (96.6/3.4) 49.7 103... 

Experimental procedure for the enzymatic esterification of oleic acid with... 

Continuous lipase catalysed esterification of oleic acid... 

In a first experiment, the esterification of oleic acid with 1-butanol catalysed by a Rhizomucor miehei lipase was investigated (Scheme 4.3). Lipases usually function at the water/organic interface, which make them extremely suitable for use in the CCS. 

Figure 4.4 Continuous two-phase hpase catalysed esterification of oleic acid in the CCS (a) Both phases once through, (b) Aqueous phase full recycle organic phase 90% recycle.

There are a few reported cases of esterases that catalyze not only hydrolysis but also the reverse reaction of ester formation, in analogy with the global reaction described for serine peptidases (Fig. 3.4). Thus, cholesterol esterase can catalyze the esterification of oleic acid with cholesterol and, more importantly in our context, that of fatty acids with haloethanols [54], Esterification and transesterification reactions are also mediated by carboxyleste-rases, as discussed in greater detail in Sect. 7.4. 

A second esterification of this type leads to a phosphatidate (enzyme l-acylglycerol-3-phosphate acyltransferase 2.3.1.51). Unsaturated acyl residues, particularly oleic acid, are usually incorporated at C-2 of the glycerol. Phosphatidates (anions of phosphatidic acids) are the key molecules in the biosynthesis of fats, phospholipids, and glycolipids. 

CRL, HLL AOT-isooctane Regioselective esterification of butane-1,3-diol with oleic acid [32]... 

Esterification between oleic acid and oleyl alcohol, catalyzed by the Mucor miehei immobihzed hpase in a batch-stirred tank reactor with supercritical carbon dioxide as solvent produced higher reaction rates at supercritical conditions than in the solvent-free system (Knez et al., 1995). 

Fig. 3 Hydrolysis and esterification by modified lipase (1mg) at 37°C. (a) was obtained at triolein (3mL) and (7mL). (b) was obtained at oleic acid (0.2mL) and glycerol (5mL). Conversion was defined as the decrement of oleic acid concentration.

The modified lipase catalyzed the esterification of oleic acid and glycerol without solvent. It showed higher activity than the unmodified lipase within the first SO hr of reaction (Figure 3b). While conversion reached 90% for all lipases, the initial rate of reaction using the modified lipase was about twice that of the unmodified lipase. 

A comparison between SCC02 and n-hexane for the esterification of oleic acid showed that in SCC02 inhibition by ethanol was less important but that vmax in n-hexane was about an order of magnitude higher. Enzyme stability was comparable and satisfactory in both cases (Marty, 1990). 

Esterification of oleic acid with methanol Sulfonic macroporous ion exchange resin Increased activity Vieville et al. (1993, 1994)... 

Marty et al. (1990) Batch Esterification of oleic acid by ethanol Lipase from Mucor miehei... 

Knez and Habulin (1992) Batch Esterification of oleic acid with oleyl alcohol Lipozyme IM... 

Esterification of oleic acid using ethanol to make ethyl oleate... 

Miller et al. (1991) demonstrated the effect of increased hydrolysis once an optimal amount of water has been added when they studied the inter-esterification of the triglycerides trilaurin and myristic acid. The observed rate of inter-esterification decreased to approximately one-third of its original rate when the water content was reduced from 1.75 (grams water per kilogram carbon dioxide) to zero. They also showed that the amount of hydrolysis increased about 10% as the water content increased. Knez et al. (1998) also found that the addition of small amounts of water increased the conversion rate when they studied the esterification of oleic acid with oleyl alcohol. 

The molar ratio of methanol to fatty acids is also an important parameter that controls the reaction. Figure 6 shows the obtained yields of methyl esters from oleic acid, a model of fatty acids, treated at various molar ratios of methanol to fatty acid. Interestingly, compared with the transesterification reaction shownby the dashed line (13), methyl esterification proceeded more at the lower molar ratio, and it is apparent that at a molar ratio of 3, oleic acid was mostly converted to its methyl ester. This result is important in designing the production process, since a reaction with a low molar ratio requires less energy for the process. 

As a simulation example we treat the production of biodiesel from rapeseed in a plant capacity of 200 ktonne per year. The feedstock has a high content of oleic acid triglyceride, around 65%, such that the kinetic data from Section 14.6 can be used for sketching the design of the reaction section. For simplification, we consider that the oil was pretreated for removing impurities and gums, as well as FFA by esterification over solid catalyst. The free fatty acids and water content in oil feed should be less than 0.5%w. NaOH and KOH in 0.5 to 1.5% w/w are used as catalysts. 

Calculate AH°S for the esterification of oleic acid with methanol using the appropriate heats of formation for the compounds. 

For the esterification of terephthalic acid with ethylene glycol at 473 K, SO /TiCh calcined at 773 K is much more active than SiC -A Ch as shown in Fig. 6 [60]. The SO /TiCh showed a maximum activity when calcined at 573 K for the esterification of oleic acid with glycerol and of propionic acid with butanol at 403 K [61], where the active sites were attributed to Bronsted acid sites from a correlation between the activity and the Bronsted acidity. The esterification of phthalic anhydride with 2-ethylhexanol to form dioctyl phthalate is also efficiently catalyzed by solid super-acids, the selectivity being more than 90% [62]. The... 

Interestingly, for maximum TAG synthesis, a preference was shown for palmitoyl-CoA as substrate for the initial acylation of glycerol-3-phosphate (Kinsella and Gross, 1973), apparently accelerating the rate of supply of substrate as acceptor for de novo-synthesized fatty adds, whereas oleic acid reduced total de novo synthesis, apparently by competing with butyryl CoA for the esterification of diacylglycerol (Hansen and Knudsen, 1987). 

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