Hydrogenation of methyl linoleate

Table I. The Homogeneous Hydrogenation of Methyl Linoleate (4 g) in the Presence of 0.65 mmol [ML2CL2] and 5.7 mmol SnCl2 in a Mixture of Benzene (30 mL) and Methanol (20 mL) at 90°C...

TABLE 3.9 Effects of Additives on the Hydrogenation of Methyl Linoleate over Palladium Catalysts 1 ... 

The bis-triphenylphosphine nickel halides are not activated by tin (II) halides. However, the iodide, (03P)2Nil2, is an effective catalyst for the hydrogenation of methyl linoleate to the monoene stage. The bromide is less effective, and the chloride has very little catalytic power. None of these nickel compounds has much ability to bring about isomerization. The nickel compounds are unstable in alcoholic solutions, and the experiments reported in Table III were carried out in either benzene, tetrahydro-furan, or toluene. 

Figure 12-11 Slurry reactor for the hydrogenation of methyl linoleate.

To illustrate the principles of slurry operation, we shall consider the hydrogenation of methyl linoleate, L, to form methyl oleate, O ... 

The catalytic hydrogenation of methyl linoleate was carried out in a laboratory-scale slurry reactor in which hydrogen gas was bubbled up through the liquid and catalyst. Unfortunately, the pilot-plant reactor did not live up to the laboratory reactor expectations. The catalyst particle size normally used was between 10 and 100 pm. In an effort to deduce the problem, the experiments listed in Table E12-5.1 were carried out on the pilot plant slurry reactor at 121°C. 

P12-19 The following table was obtained from the data taken in a slurry reactor for the hydrogenation of methyl linoleate to form methyl oleate. 

The mechanism for homogeneous hydrogenation of methyl linoleate by Fe(CO)s based on kinetic evidences and radioactive tracers involves monoene- and diene-Fe(CO)4 and diene-Fe(CO)3 complexes as important intermediates. Contrary to our previous postulate (7) the free conjugated diene is only a minor intermediate. Confirmatory evidence is needed for the occurrence of oleate- and linoleate-Fe(CO)4 complexes during hydrogenation and isomerization with Fe(CO)r>. Also, the species of iron carbonyl hydrides formed during hydrogenation should be elucidated. 

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 ... 

Figure 8.7 Hydrogenation of methyl linoleate with catalyst size 1 at 121 °C. (From Ref. 10 with permission from Elsevier Science.)...

J. C. Bailar, Jr., and Hiroshi Itatani, Homogeneous Catalysis in the Reactions of Olefinic Substances. VI. Selective Hydrogenation of Methyl Linoleate and Isomerization of Methyl Oleate by Homogeneous Catalysis with Platinum Complexes Containing Triphenylphosphine, Arsine or Stibine, J. Am. Chem. Soc. 89 1592 (1967). 

Scheme 4-330. Hydrogenation of methyl linoleate catalyzed by pentacarbonyliron.

---