Methyl stearate catalyst

Bancquart, S., Vanhove, C., Pouilloux, Y. and Barrault, J. Glycerol transesterification with methyl stearate over solid basic catalysts. I. Relationship between activity and basicity, Appl. Catal., A, 2001, 218, 1-11. 

Derivation By reaction of sugar and methyl stearate in a suitable solvent and with potassium carbonate catalyst. 

Fig. 4.3. (A) Analytical catalytic reactor with bypass. 1 = Catalyst 2 = glass-wool 3 = stainless-steel capillary. (B) Chromatograms of methyl esters of Cj, acids after hydrogenation using the analytical catalytic reactor with bypass. Peaks 1 = methyl stearate 2 = methyl oleate 3 = methyl linoleate 4 = methyl linolenate. Reprinted with permission from ref. 79.

Changing particle size can provide experimental evidence about the internal and external catalyst resistances. For small particles, varies with, whereas rjk may vary with d to depending on the value of the Thiele modulus. Figures 8.7 and 8.8 show data for the hydrogenation of methyl linoleate using Pd-carbon as a catalyst [10]. The two steps in the reaction are the conversion of doubly unsaturated linoleate, L, to oleate, O, and the reaction of oleate to saturated methyl stearate, S ... 

The hydroformylation reaction converts the unsaturation into a carbonyl moiety, as illustrated in the example of Scheme 2.6, in which methyl oleate is converted into methyl-9-stearate with methyl stearate as a byproduct, under the action of a rhodium-based catalyst. 

Keep the temperature of the reaction mixture at about 40°C imtil you perform the centrifugation otherwise, the methyl stearate may crystallize and interfere with removal of the catalyst. There should not be any white solid (product) in the round-bottom flask. If there is a white solid, add more methanol and stir until the solid dissolves. 

Continuous reactor. Stearic acid allowed to react at 90-120° with methanol in the presence of ferric sulfate as catalyst in a column or cascade reactor during less than 5 hrs. methyl stearate. Y almost 100%. J. Broniarz and J. Szymanowski, Przem. Chem. 52(1), 30 (1972) (Pol) C. A. 76, 112623. 

Table 13.10 Catalyst properties and their catalytic performance for the transesterification of methyl stearate with glycerol. Reaction conditions temperature 220°C glycerol/methyl stearate 1 time on stream 6 h weight of catalyst 0.5 g Nj atmospheric pressure.

Metal phthalocyanine complexes are also frequently used as autoxidation catalysts (see Section II.B.2). They have generally been found to be more active than the corresponding stearates or acetylacetonates. Thus, Uri145 compared the catalytic activity of a series of transition metal stearates with the corresponding metal phthalocyanines in the autoxidation of methyl linoleate. The phthalocyanine complexes afforded faster rates of oxidation. In addition, the phthalocyanine ligand is stable and is not easily destroyed under autoxidizing conditions. Interest in metal phthalocyanine catalysts has also been stimulated by their resemblance to the metal-porphyrin structures contained in many oxidative enzymes (see Sections II.B.2 and V). 

After these experiments, concerning the oxidative cleavage of aliphatic ketone, the methyl-keto fatty adds, prepared by direct oxidation of co-unsaturated fatty acids, were put to use. The oxidations were carried out in a bubble column reactor at 115 °C over a retention time of 60 min with 2 mol-% Mn(stearate)2 as catalyst. Afterwards the reaction mixture was cooled to room temperature and the solvent acetic acid was removed at 30 °C in vacuum. 

ROP is carried out in solution, in the melt, in the bulk or in suspension. The involved mechanism can be ionic (anionic or cationic), coordination-insertion or free-radical polymerization [19].The cationic pol)rmerization is initiated by only two catalysts, trifluoromethane-sulphonic acid and its methyl ester [10, 15]. Initiators such as potassium methoxide, potassium benzoate, zinc stearate, n-, sec-, fer-butyl lithium or 18-crown-6-ether complexes are added for the anionic polymerization to induce a nucleophilic reaction on the carbonyl to lead to an acyl-oxygen link cleavage. According to Jedkinski et al. only the primary alkoxides, such as the first mentioned catalyst, can yield polymers with negligible racemization, transesterification and termination [10]. 

The oxidation of cyclohexanone is a reaction which has been the subject of considerable study over the years. Continued research in this area has given rise to many recent patents and papers. The product of the oxidation reaction is rather dependent on the metal complex which is used as a catalyst. When manganese(III) complexes are used the major reaction product is adipic acid [280-288]. Selectivity to adipic acid is about 70% in most cases. When copper(II) complexes are used, 5-formylvaleric acid predominates [289, 290] whereas iron complexes catalyze the formation of e-caprolactone [291,292] in up to 56% yield. In fact, liquid phase air oxidation of 2-methyl-cyclohexanone at 100 °C in the presence of copper stearate gave e-methyl- -caprolactone [292a]. Reaction scheme (190) shows the predominant reaction pathways. 

By the effect of a Rh/C catalyst modified with PPhg at 140 bar syngas pressure and 110 °C on a complex substrate mixture of fatty acid methyl esters with one or more double bonds, besides the formation of monoformyl stearate, some diformy-lated products were found [34]. Moreover, unsaturated monoformyl esters were detected together with triformyl esters derived from methyl linolenate. The formation of 1,4-diformyl esters in the hydroformylation of methyl linoleate over the 1,3-diformyl isomers was explained by the thermodynamic stability of the transient Rh-acyl complex A over the chelate B with a smaller ring size. 

Biodiesel, a mixture of fatty acid methyl esters, is manufactured by transesterification of natural glycerides by MeOH. Zinc laurate, palmitate, and stearate are effective catalysts in this process and a theoretical and experimental study showed that the mechanism involves initial coordination of MeOH followed by a carboxylate ion acting as a general base to generate an incipient alkoxide-like moiety that attacked the coordinated triglyceride. ... 

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