Studies on kinetics of catalytic isomerization of methyl linoleate

Abstract

12 53 35 21 50 29 Olein Oil Stearin 37.5 38 45 41.5 39.5 50.5The free fatty acids do have the approximately random distribution that would be expected by random hydrolysis of the triglycerides. In contrast, the mono-and diglycerides have a distribution which is different from random. As previously noted, detergent fractionation concentrates FFA and diglyceride in the olein and monoglyceride in the stearin. The results given in Figure 3 also show that the proportion of P and 0 and of PP, PO and 00 change, with the more unsaturated partial glycerides, like the triglycerides, concentrating in the olein.On bleaching, FFA increases slightly, monoglycerides are reduced and diglycerides are unchanged.After steam refining and deodorization FFA is reduced almost to zero. For palm stearin, the proportions of P and o seem to have altered, but since P (mainly palmitic acid) would be expected to be more volatile, this may be due to experimental error at these very low levels. Monoglycerides also are substantially reduced, with 0 (mainly monoolein) being the only detectable monoglyceride. Total diglycerides show no significant change, but the proportions of PP, PO and 00 do change in the direction of increased random distribution. ABSTRACTKinetics of isomerization of methyl linoleate are studied on ruthenium (5%) on carbon in the temperature range 200-270 C with different solvents. Some equilibrium experiments also are carried out with rhodium and ruthenium catalysts. The reactions taking place are isomerization, hydrogenation and polymerization. The activities and the selectivities are dependent on the nature of the solvent used. Highly protic solvents like methanol or isopropyl alcohol exhibited very high activity and selectivity for hydrogenation, whereas aprotic solvents like hexane or cyclohexane showed very high selectivities for isomerization reaction. The reaction kinetics were found to be further complicated by polymer formation at low solvent concentrations. The effects of temperature, solvent concentration, catalyst quantity and time of reaction also were investigated.

Catalytic Transformations for Production of Fine Chemicals and Pharmaceuticals from Wood‐Derived Raw Materials

“…2.2). On the other hand, the isomerization of methyl linoleate over heterogeneous catalysts has been reported earlier, and the catalysts applied were rhodium and ruthenium on activated carbon [32,33], as well as bimetallic supported ruthenium nickel catalysts [34].…”

Catalytic Production of Conjugated Fatty Acids and Oils

“…The reaction network is further complicated by polymer formation, which is most pronounced at high temperature, low solvent content, and high catalyst concentration. [89] Polymerization competes with the isomerization reaction and is also metal-catalyzed. Addition of small quantities of Ni to Ru/C increases the catalyst activity due to higher Ru dispersion, and it favors the formation of cis/trans CLA in expense of trans/trans CLA isomers.…”

Current Knowledge on Source and Synthesis of Conjugated Linoleic Acid (CLA): A Review

“…Hence, heterogeneous catalysts are advised for isomeriation reaction of linoleic acid. Solvents containing hydrogen transfer agents are used for isomeriation of methyl linoleate and rhodium and ruthenium supported with carbon was used as catalysts between 200 and 270 ˚C in different solvents [60,61].…”