Catalytic behavior of palladium in the hydrogenation of edible oils

Hsu, Nathan Sung Yuan; Dlosady, L. L.; Rubin, L.J.

doi:10.1007/bf02663075

Cited by 48 publications

(31 citation statements)

References 5 publications

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“…→ stearic [7] The relative rates of the individual reactions were quantitated in terms of three selectivities, [8] The rate constants in the above equations were determined by combining the fatty acid compositions of the starting oil and final product, for a given SPE reactor experiment, with the following first-order rate expressions: [9] Soybean oil fatty acid selectivities in the SPE reactor were comparable to those from chemical catalytic hydrogenations in a slurry reactor with H 2 gas and a Pt/Al 2 O 3 catalyst, where SLn = 1.35 and SLo = 0.85 at 60°C and 145 psig (20). On the other hand, the SPE selectivities were not as high as those from a Pd/C or nickel catalyst slurry reactor.…”

Section: Resultsmentioning

confidence: 99%

The electrochemical hydrogenation of edible oils in a solid polymer electrolyte reactor. I. Reactor design and operation

Hong

Pintauro

et al. 1998

J Americ Oil Chem Soc

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A new electrochemical method has been devised and tested for the moderate temperature/atmospheric pressure hydrogenation of edible oils, fatty acids, and fatty acid methyl esters. The method employed a solid polymer electrolyte (SPE) reactor, similar to that used in H 2 /O 2 fuel cells, with water as the source of hydrogen. The key component of the reactor was a membrane-electrode-assembly, composed of a RuO 2 powder anode and either a Pt-black or Pd-black powder cathode that were hot-pressed as thin films onto the opposing surfaces of a Nafion cation-exchange membrane. During reactor operation at a constant applied current, water was back-fed to the RuO 2 anode, where it was oxidized electrochemically to O 2 and H + . Protons migrated through the Nafion membrane under the influence of the applied electric field and contacted the Pt or Pd cathode, where they were reduced to atomic and molecular hydrogen. Oil was circulated past the back side of the cathode and unsaturated triglycerides reacted with the electrogenerated hydrogen species. The SPE reactor was operated successfully at a constant applied current density of 0.10 A/cm 2 and a temperature between 50 and 80°C with soybean, canola, and cottonseed oils and with mixtures of fatty acids and fatty acid methyl esters. Reaction products with iodine values in the range of 60-105 were characterized by a higher stearic acid content and a lower percentage of trans isomers than those produced in a traditional hydrogenation process. JAOCS 75, 917-925 (1998). FIG. 1. Principles of operation of a solid polymer electrolyte (SPE) reactor during the electrohydrogenation of an oil.

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Section: Resultsmentioning

confidence: 99%

The electrochemical hydrogenation of edible oils in a solid polymer electrolyte reactor. I. Reactor design and operation

Hong

Pintauro

et al. 1998

J Americ Oil Chem Soc

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“…However, changes in hydrogen pressure (1-3 bar) did not result in the same effects, which is because of the low hydrogen pressure range used in this work. Other researchers [6,7] stated that application of high pressure reduces trans formation at significant levels.…”

Section: Resultsmentioning

confidence: 97%

“…Hydrogenation reactions have more selective characters at higher temperatures but lower hydrogen pressures and stirring speeds [5], and more selective reactions produce fats with higher trans contents. However, very high hydrogen pressure (750 psi) and low temperature (70 7C) not only decreased trans formation but also the selectivity ratios, despite using a highly selective catalyst, 5% Pd on Al 2 O 3 [6]. Similar findings were found by List et al [7] where the trans content decreased from 17.8 to 10.4% at about 80 IV by increasing the pressure from 50 to 500 psi at 120 7C, a Ni content of 0.25% and high-speed stirring.…”

Section: Introductionmentioning

confidence: 98%

Effects of hydrogenation parameters on trans isomer formation, selectivity and melting properties of fat

Musavi¹,

Çizmeci

Tekin

et al. 2008

Euro J Lipid Sci & Tech

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Effects of hydrogenation conditions (temperature, hydrogen pressure, stirring rate) on trans fatty acid formation, selectivity and melting behavior of fat were investigated. To this aim, soybean oil was hydrogenated under various conditions and fatty acid composition, trans isomer formation, slip melting point (SMP), solid fat content (SFC) and iodine number (IV) of the samples withdrawn at certain intervals of the reactions were monitored. A constant ratio (0.03%) of Nysosel 222 was used in the various combinations of temperature (150, 165 and 180 7C), stirring speed (500, 750 and 1000 rpm) and hydrogen pressure (1, 2 and 3 bar). Raising the temperature increased the formation of fatty acid isomers, whereas higher stirring rates decreased this formation, while changes in hydrogen pressure had no effect or slightly reduced it, depending on other parameters. Results also indicated that the trans fatty acid ratio increased with IV reduction, reached the highest value when the IV was about 70 and decreased at IV , 70 due to saturation. Selectivity values (S 21 ) at that point ranged between 5.78 and 11.59. Lower temperatures and higher stirring rates decreased not only the trans isomer content but also the S 21 values at significant levels. However, same effects were not observed with the changes in hydrogen pressure. It was determined that a high SMP does not necessarily mean a high SFC. Selective conditions produced samples with higher SFC but lower SMP, which is possibly because of higher trans isomer formation as well as lower saturation.

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“…This important area of catalytic chemistry has been the foundation for the development of numerous diverse, small-and large-scale commercial hydrogenation processes, which include synthesis of fine and specialty chemicals such as agrochemicals 1,2 , flavours and fragrances [3][4][5][6][7][8] , food additives [9][10][11][12][13][14][15][16] and pharmaceuticals [17][18][19][20][21] . The hydrogenation of 2-((1-benzyl-1,2,3,6-tetrahydropyridin-4-yl)methylene)-5,6-dimethoxy-2,3--dihydroinden-1-one hydrochloride (1) to 2-((1-benzylpiperidin-4-yl)methyl)-5,6-dimethoxy-2,3-dihydroinden-1-one hydrochloride (4), which is the last production step for the preparation of (4), is one such industrial important reaction.…”

Section: Introductionmentioning

confidence: 99%

reKinetics and Mass Transfer in the Hydrogenation of 2-((1-benzyl-1,2,3,6-tetrahydropyridin-4-yl)methylene)-5,6-dimethoxy- -2,3-dihydroinden-1-one hydrochloride over Pt/C Catalyst

Zrnčević¹

2015

Chem.Biochem.Eng.Q.

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The liquid phase hydrogenation of 2-((1-benzyl-1,2,3,6-tetrahydropyridin-4-yl) methylene)-5,6-dimethoxy-2,3-dihydroinden-1-one hydrochloride (1) over a 5 % Pt/C industrial catalyst was studied experimentally in a batch slurry reactor using methanol as a solvent. The catalyst was characterized by the adsorption techniques for specific surface area and pore volume, and by XRD for crystallinity. To investigate the intrinsic kinetics of the reaction, the effect of temperature, catalyst loading, hydrogen partial pressure and (1) concentration on the initial rate of hydrogenation was studied. The analysis of initial rate data showed that the gas-liquid, liquid-solid, and intraparticle mass-transfer resistances were not significant. The reaction scheme of (1) hydrogenation was proposed for the kinetic modelling. Apparent rate constants for all hydrogenation steps were calculated using a first order kinetic approach resulting in good agreement between the experimentally obtained and predicted concentrations. From the temperature dependence of rate constants, the activation energies of various reaction steps were calculated. The averaged activation energy of these steps was found to be 31.1 kJ mol -1 .

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Catalytic behavior of palladium in the hydrogenation of edible oils

Cited by 48 publications

References 5 publications

The electrochemical hydrogenation of edible oils in a solid polymer electrolyte reactor. I. Reactor design and operation

The electrochemical hydrogenation of edible oils in a solid polymer electrolyte reactor. I. Reactor design and operation

Effects of hydrogenation parameters on trans isomer formation, selectivity and melting properties of fat

reKinetics and Mass Transfer in the Hydrogenation of 2-((1-benzyl-1,2,3,6-tetrahydropyridin-4-yl)methylene)-5,6-dimethoxy- -2,3-dihydroinden-1-one hydrochloride over Pt/C Catalyst

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