Kinetic peculiarities of cis/trans methyl oleate formation during hydrogenation of methyl linoleate over Pd/MgO

Deliy, Irina V.; Maksimchuk, Nataliya V.; Psaro, Rinaldo; Ravasio, Nicoletta; Santo, Vladimiro Dal; Recchia, Sandro; Паукштис, Е. А.; Golovin, A. V.; Semikolenov, V. A.

doi:10.1016/j.apcata.2004.10.017

Cited by 23 publications

(21 citation statements)

References 34 publications

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“…This indicates that the full hydrogenation of linoleic or oleic acid did not occur, whereas partial hydrogenation to mono‐unsaturated fatty acids and conjugated and cis – trans geometric isomerization activities increased with time 58. These observations were confirmed by the experimental data in Table 3.…”

Section: Resultssupporting

confidence: 65%

Sulfur Promotion in Conjugated Isomerization of Safflower Oil over Bifunctional Structured Rh/SBA‐15 Catalysts

et al. 2013

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The sulfur effect on conjugated linoleic acid isomer (CLA) formation during the combined hydrogenation/directed isomerization of safflower oil over a bifunctional (hydrogenation and isomerization) highly structured rhodium‐based catalyst (Rh/SBA‐15) was investigated either by direct addition of increased concentrations of 3‐mercapto‐1,2‐propanediol to the reaction medium or by doping Rh/SBA‐15 with the same sulfur‐based compound yielding the sulfur‐doped Rh‐catalyst (S–Rh/SBA‐15). These catalysts exhibited interesting activity, stability, and recyclability. The maximum CLA contents obtained during the combined reactions with 0, 0.2, 1, 2, 5, and 10 ppm sulfur additions were 73, 99, 131, 110, 105, and 68 mgCLA goil−1, respectively, whereas the amount of harmful trans monoenes remained below 8 %. The safflower oil after partially hydrogenation under the same conditions over S–Rh/SBA‐15 catalyst contained up to 110 mgCLA goil−1. These results showed clear evidence of the sulfur promotion effect on CLA formation during the dual hydrogenation/directed isomerization of safflower oil. A mechanism for the sulfur promotion of the heterogeneous catalyst Rh/SBA‐15 for the conjugated isomerization activity during hydrogenation/directed isomerization of safflower oil was determined by solid‐state 1H NMR analysis of the fresh and spent catalysts. This was also confirmed by liquid‐state 2H NMR analysis of deuterium‐labeled product aliquots withdrawn throughout the reaction. The sulfur promotion towards the double bond conjugation of linoleic acid to form CLA isomers could be explained mechanistically through the preferable formation of the more nucleophilic rhodium sulfide (RhSH) over that of the hydride (RhH). However, both types of Rh clusters constituted distinct catalytic sites leading to the formation of hydrogenation as well as conjugated and geometric isomerization products. The lumped kinetics model described the experimental data well and complied simply with the proposed mechanism.

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Section: Resultssupporting

confidence: 65%

Sulfur Promotion in Conjugated Isomerization of Safflower Oil over Bifunctional Structured Rh/SBA‐15 Catalysts

et al. 2013

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“…5c shows that a higher temperature slightly enhanced the formation of fatty acid trans-isomers at cis-C18:2 conversion >50%. Deliy et al [61] suggested this effect was related to a reduction of concentration of hydride modes on the catalyst surface that led to an increased contribution of isomerisation.…”

Section: Hydrogenation Of Soybean Oilmentioning

confidence: 98%

“…S1 and S2). At the reaction onset, it is likely that the catalyst surface is saturated with the cis-C18:3 and cis-C18:2 components due to the strong multi-site adsorption via multiple C C double bonds and the C O bond of carbonyl groups [61]. Fig.…”

Section: Hydrogenation Of Soybean Oilmentioning

confidence: 99%

Selective hydrogenation using palladium bioinorganic catalyst

Zhu

Wood

Deplanche

et al. 2016

Applied Catalysis B: Environmental

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a b s t r a c tPalladium bioinorganic catalyst (bio-Pd) was manufactured using bacteria (Desulfovibrio desulfuricans and Escherichia coli) via the reduction of Pd(II) to bio-scaffolded Pd(0) nanoparticles (NPs). The formed Pd NPs were examined using electron microscopy and X-ray powder diffraction methods: a loading of 5 wt% Pd showed an average particle size of ∼4 nm. The catalytic activities of the prepared bio-Pd NPs on both bacteria were compared in two hydrogenation reactions with that of a conventionally supported Pd catalyst (Pd/Al 2 O 3 ). Concentration profiles of the different hydrogenation products were fitted using a Langmuir-Hinshelwood expression. In 2-pentyne hydrogenation, 5 wt% Pd E.coli achieved 100% of 2-pentyne conversion in 20 mins and produced 10.1 ± 0.7 × 10 −2 mol L −1 of desired cis-2-pentene; in contrast 5 wt% Pd/Al 2 O 3 yielded 6.5 ± 0.4 × 10 −2 mol L −1 of cis-2-pentene after 40 mins. In the solvent-free hydrogenation of soybean oil, the use of 5 wt% Pd E.coli yielded cis-C18:1 of 1.03 ± 0.04 mol L −1 and trans-C18:1 of 0.26 ± 0.03 mol L −1 (∼50% less of the latter than 5 wt% Pd/Al 2 O 3 ) after 5 h. Similar results were obtained using bio-Pd E.coli and bio-Pd D.desulfuricans . Bio-Pd was concluded to have the advantage of a lower cis-trans isomerisation in hydrogenation of alkyne/alkenes. Hence biomanufacturing is an environmentally attractive, scalable and facile alternative to conventional heterogeneous catalyst for application in industrial hydrogenation processes. D. desulfuricans is inconvenient to grow at scale but wastes of E. coli are produced from various industrial processes. 'Second life' (i.e. recycled from a pilot scale biohydrogen production process) E. coli cells were used to make bio-Pd catalysts. Although 'bio-Pd secondlife gave a slower conversion rate of 2-pentyne and soybean oil compared to bio-Pd from purpose-grown cells it showed a higher selectivity to the cis-isomer product.

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“…Nevertheless, the selected model did not consider the distinct dependency on hydrogen for the saturation and isomerization reactions. Deliy et al [30] proposed a qualitative explanation of the hydrogenation of methyl linoleate into cis or trans methyl oleate which was taken over by Murzin and Simakova [31] later on: following the first addition of H on the methyl linoleate, the authors assumed the presence of either a pro-cis or pro-trans intermediate preceding the second addition of H and giving either the methyl oleate (cis) or the methyl elaidate (trans), respectively. Kinetic laws were derived but parameters values were not given.…”

Section: Contextmentioning

confidence: 99%

Sunflower oil hydrogenation mechanisms and kinetics

Albrand

Julcour-Lebigue

Veyrine

et al. 2021

Chemical Engineering Journal

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A kinetic model for sunflower oil hydrogenation on a palladium catalyst is proposed based on Horiuty-Polanyi type mechanism and considering either a dissociative or associative adsorption of hydrogen. The derived kinetic laws allow to explain the distinct dependency of saturation and isomerization reactions on hydrogen pressure.Kinetic parameters are identified based on batch slurry hydrogenations carried out at 60-160 • C and 2-31 bar with a powdered Pd/Al 2 O 3 catalyst. A statistical analysis is used to select the most suitable adsorption mechanism for H 2 . Evaluation of the Weisz-Prater modulus reveals that limitations to intraparticle diffusion occur despite the particle diameter does not exceed 40 μm.

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Kinetic peculiarities of cis/trans methyl oleate formation during hydrogenation of methyl linoleate over Pd/MgO

Cited by 23 publications

References 34 publications

Sulfur Promotion in Conjugated Isomerization of Safflower Oil over Bifunctional Structured Rh/SBA‐15 Catalysts

Sulfur Promotion in Conjugated Isomerization of Safflower Oil over Bifunctional Structured Rh/SBA‐15 Catalysts

Selective hydrogenation using palladium bioinorganic catalyst

Sunflower oil hydrogenation mechanisms and kinetics

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