Production ethyl-oleate

A novel method for production of paraffinic hydrocarbons, suitable as diesel fuel, from renewable resources was illustrated. The fatty acid ethyl ester, ethyl stearate, was successfully converted with high catalyst activity and high selectivity towards formation of the desired product, heptadecane. Investigation of the impact of catalyst reduction showed that the reduction pretreatment had a beneficial effect on the formation of desired diesel compound. The non-pretreated catalyst dehydrogenated ethyl stearate to ethyl oleate. The experiments at different reaction temperatures, depicted that conversion of ethyl stearate was strongly dependent on reaction temperature with Eact=69 kj/mole, while product selectivities were almost constant. Complete conversion of ethyl stearate and very high selectivity towards desired product (95%) were achieved at 360°C. 

In order to increase the sustainability of chemical processes, environmentally friendly solvents such as supercritical fluids (SCFs) are widely investigated. Han and coworkers studied the ethenolysis of ethyl oleate in SC C02 in relation with the phase behavior of the reaction mixture [62]. They carried out the ethenolysis reaction at 35°C in the absence of C02 and in the presence of C02 at three different pressures (50, 82, and 120 bar). The reaction in the absence of C02 reached equilibrium in 1 h at 80% conversion. The reaction rate in the presence of 50 bar of C02 was higher than without C02 and, at 82 bar, again increased with respect to 50 bar. However, when the pressure was increased to 120 bar, the reaction rate decreased. This effect was explained according to the variations on the phase behavior with the pressure an increase in the C02 pressure carried an increase of solubility of reactants, products, and C02, which produced a decrease of the viscosity of the reaction mixture. This positive effect was enhanced at 82 bar and was accompanied by an increase of selective solubility of the products in the vapor phase that further increased both reaction rate and conversion. The decrease of efficiency at 120 bar was related to an increase of the solubility of the reactants in the C02 phase. 

The catalyst system [Rh(acac)(CO)2]/biphephos shows high activity for isomerization with yields of 60% of branched isomers at 20 bar CO/H2 pressure and 115°C [10]. With this catalyst system, a 26% selectivity of linear aldehyde from ethyl oleate was observed. The selectivity for the n-aldehvde was higher at 34% for linoleic acid. A hydrogenation side product was observed in the reaction due to the isomerization of the double bond toward the ester group, where hydrogenation is favored. 

A rhodium catalyst [Rh(cod)Cl]2 was applied at 140°C and 100 bar to achieve a yield of 99% in hydroaminomethylation of ethyl oleate and morpholine. Several amines were tested in the reaction with fatty compounds hexylamine, benzylamine, aspartic diethyl acid, valinol, and diisopropylamine are further amines which can be employed in hydroaminomethylation. The conversion with primary amines showed that hydroaminomethylation can proceed twice on the amine. The dimer fatty acid ester bridged with an amine is a highly functionalized molecule with various applications. An excess of the primary amine during the reaction prohibits the reaction of the hydroformylation product with a secondary amine which is the product of hydroaminomethylation with the primary amine (Scheme 19). 

The products of lipid oxidation in monolayers were also studied. Wu and coworkers (41) concluded that epoxides rather than hydroperoxides might be the major intermediates in the oxidation of unsaturated fatty acids adsorbed on silica, presumably because of the proximity of the substrate chains on the silica surface. In our work with ethyl oleate, linoleate and linolenate which were thermally oxidized on silica, the major decomposition products found were those typical of hydroperoxide decomposition (39). However, the decomposition patterns in monolayers were simpler and quantitatively different from those of bulk samples. For example, bulk samples produced significantly more ethyl octanoate than those of silica, whereas silica samples produced more ethyl 9-oxononanoate than those of bulk. This trend was consistent regardless of temperature, heating period or degree of oxidation. The fact that the same pattern of volatiles was found at both 60°C and 180°C implies that the same mode of decomposition occurs over this temperature range. 

A membrane cell recycle reactor with continuous ethanol extraction by dibutyl phthalate increased the productivity fourfold with increased conversion of glucose from 45 to 91%.249 The ethanol was then removed from the dibutyl phthalate with water. It would be better to do this second step with a membrane. In another process, microencapsulated yeast converted glucose to ethanol, which was removed by an oleic acid phase containing a lipase that formed ethyl oleate.250 This could be used as biodiesel fuel. Continuous ultrafiltration has been used to separate the propionic acid produced from glycerol by a Propionibacterium.251 Whey proteins have been hydrolyzed enzymatically and continuously in an ultrafiltration reactor, with improved yields, productivity, and elimination of peptide coproducts.252 Continuous hydrolysis of a starch slurry has been carried out with a-amylase immobilized in a hollow fiber reactor.253 Oils have been hydrolyzed by a lipase immobilized on an aromatic polyamide ultrafiltration membrane with continuous separation of one product through the membrane to shift the equilibrium toward the desired products.254 Such a process could supplant the current energy-intensive industrial one that takes 3-24 h at 150-260X. Lipases have also been used to prepare esters. A lipase-surfactant complex in hexane was used to prepare a wax ester found in whale oil, by the esterification of 1 hexadecanol with palmitic acid in a membrane reactor.255 After 1 h, the yield was 96%. The current industrial process runs at 250°C for up to 20 h. 

Cross-metathesis reactions are useful for the production of fine chemicals such as synthetic perfumes, prostaglandin intermediates, and insect pheromones. An example of the last is the cross-metathesis of ethyl oleate with 5-decene in the presence of a MoCl5/Si02/Me4Sn catalyst at 90 °C [14], or a Mo03/Si02/cyclopropane catalyst at 50 °C [16], resulting in a cisitrans mixture of ethyl 9-tetradecenoate, an insect pheromone precursor (Eq. 12). 

Because the free enthalpy change in this type of reaction is virtually zero, the result at equilibrium is a random distribution of the alkylidene groups. Thus, starting with methyl oleate, the equilibrium mixture consists of 50 mol% of the starting material and 25 mol% of each of the products 9-octadecene and dimethyl 9-octadecene-1,18-dioate. The cis/trans ratio of the reaction products is also in accordance with thermodynamics. This demonstrates that - in the presence of a suitable catalyst - the metathesis of unsaturated fatty acid esters provides a convenient and highly selective route to unsaturated diesters. Unsaturated diesters are important intermediates for the production of useful chemical products such as macrocyclic compounds. For instance, the diester obtained by metathesis of ethyl oleate has been subjected to a two-step reaction sequence, i.e. a... 

Figueiredo K C S, SaUm VMM and Borges C P (2010), Ethyl oleate production by means of pervaporation-assisted esterification using heterogeneous catalysis ,... 

The turnover rates (Table 3) are lower than those obtained with 1 in the metathesis of 2-pentene or ethyl oleate, suggesting a reversible coordination of the sulfur compound to the metallocarbene leading to a partial deactivation of the catalyst. Nevertheless, the reaction is highly selective (only the expected metathesis products are detected) and the conversion of 4 can reach a high value when an excess of the co-reactant olefin is used. 

In 1993, Okamoto et al. studied the reactive pervaporation process for the production of ethyl oleate starling from oleic acid and ethanol. An ESU configuration was used together with a noncatalytic asymmetric PEF4,4-oxydiphenylene pyromelliti-mide and p-toluene sulfonic acid as catalyst. A model was set by the authors (coupling reaction kinetics with the pervaporafion permeate flux relation) to evaluate all critical parameters to tune PVMR parameters and obtain a conversion of 98%. 

Ethyl docosahexaenoate-treated foetal rat brain preparations exhibited an almost 70 % decrease in the amount of 5,5 -dimethyl-l.pyrroline-N-oxide-OH adducts compared to those from ethyl oleate-treated animals (Green et al. 2001). The decreased lipid peroxide production, as well as increased production of prostaglandin Ej and nitric oxide by the foetal brain following ethyl docosahexaenoate administration could be mimicked by a synthetic qui-none possessing both hydroxyl radical producing and lipid peroxide propagation inhibiting properties. 

In comparison to methyl oleate, somewhat higher yields of monoformyl product were observed in the hydroformylation of ethyl linoleate (Scheme 6.83) [26]. Under the same conditions, besides isomeric aldehydes, ethyl oleate and ethyl stearate were formed. Higher syngas pressure reduced the degree of hydrogenation. 

Butanol, which at one time was an unwanted by-product in the preparation of acetone, is now the most important product of the fermentation. The building of a large new factory in Puerto Rico using 10,000 tons of molasses per annum for its production is an indication of this importance. Butanol is probably still the best solvent for cellulose nitrate lacquers. Dibutyl phthalate is certainly the most widely used plasticizer for synthetic resins, and butyl oleate, tributyl citrate and dibutyl tartrate have also been described as plasticizers. Another important use of butanol is as a source of butadiene, which serves as an intermediate in the conversion of sucrose into a synthetic rubber. Although in recent years other methods have been described for the preparation of butanol (for example, from ethyl alcohol and from acetylene), yet the fermentation of carbohydrates is still the cheapest process. 

The hydrogenation of an unsaturated ester to an unsaturated alcohol may be possible over zinc-chromium oxide as catalyst, although the catalyst is known to be much less active for the usual ester hydrogenations than copper-chromium oxide. Ethyl or butyl (eq. 10.25) oleates were hydrogenated to octadecenol in yields of over 60% with a zinc-chromium oxide at 280-300°C and 20 MPa H2.16 The butyl ester was much preferred to the ethyl ester, since it was difficult to separate the ethyl ester from the alcohol product because of their similar boiling points. 

Such catalysts include potassium acetate, sodium benzoate, certain basic inorganic salts (IS, 21, 22), lead oleate and other lead salts (23), alkali soaps (23), and metal naphthenates (2Ji). Also at 125°, trimers of phenyl isocyanate form in high yield catalyzed by A-methylmorpholine in the presence of ethyl alcohol (26). Epoxides have been reported to be active for trimerization in the presence of a small amount of amine (26, 27). Ethylene carbonate also is effective in production of trimer (28). Recently... 

In situ product separation by distillation offers applications in esterification (e.g., for ethyl acetate), trans-esterification (e.g., for butyl acetate), hydrolysis (e.g., for ethylene glycol, isopropyl alcohol), metathesis (e.g., for methyl oleate), etherification (e.g., for MTBE, ETBE, TAME), and alkylation reactions (e.g., for cumene). 

A large proportion of the volatiles identified in vegetable oils are derived from the cleavage reactions of the hydroperoxides of oleate, linoleate, and linolenate (Section D). A wide range of hydrocarbons (ethane, propane, pentane and hexane) appears to be formed in soybean oil oxidized to low peroxide values. A number of volatiles identified in vegetable oils that are not expected as primary cleavage products of monohydroperoxides include dialdehydes, ketones, ethyl esters, nonane, decane, undecane, 2-pentylfuran, lactone, benzene, benzaldehyde and acetophenone. Some of these volatiles may be derived from secondary oxidation products, but the origin of many volatiles still remains obscure. However, studies of volatile decomposition products should be interpreted with caution, because the conditions used for isolation and identification may cause artifacts, especially when fats are subjected to elevated temperatures. 

Table X. Composition of transesterification products of sucrose chelates and alcoholates with ethyl acetate, methyl caprinate, laurate, stearate, oleate, and ethyl methacrylate in DMF, 3 h, 80°-120°C, mole-%.

The addition of such electrolytes as KCl and BaCl2 in quantities not exceeding 0.1 mole/liter to solutions of propyl, ethyl, and methyl alcohols leads to an increased adhesion. We noted something rather similar (Fig. IV.18) when studying adhesion in solutions of surface-active substances (commercial products containing small quantities of electrolytes). The fact that the adhesive forces in solutions of T Duomin, NT Armak, and sodium oleate exceed the expected values may clearly be attributed to the presence of such electrolytes. 

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