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

Abstract

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.

Selectivity in sorption and hydrogenation of methyl oleate and elaidate on MFI zeolites

“…elaidate (tC18:1), are legally restricted for dietary reasons [3][4][5]. Main efforts from industry to obtain products low in trans include: (1) changes of the hydrogenation parameters [2,6], (2) use of noble metal catalysts containing Pt and Pd [7,8], (3) use of catalytic transfer [9,10], electrocatalytic hydrogenation [11][12][13] and hydrogenation in supercritical conditions [14][15][16][17], (4) use of alternative processes and feeds, including chemical [18,19] and enzymatic interesterification [20], fractionation [21], and (5) use of naturally stable oils low in linolenic acid [22,23].…”

Low‐trans Shortening and Spread Fats Produced by Electrochemical Hydrogenation

“…Although electrochemical hydrogenation has been studied in the laboratory [5][6][7][8][9][10], little information has been published on the functional and physical properties of oils produced by this technology. Electrochemical hydrogenating edible oils employs a proton-exchange membrane (PEM) reactor, similar to that used in H 2 /O 2 fuel cells, with water or H 2 gas as the source of hydrogen [5][6][7][8][9].…”

“…Electrochemical hydrogenating edible oils employs a proton-exchange membrane (PEM) reactor, similar to that used in H 2 /O 2 fuel cells, with water or H 2 gas as the source of hydrogen [5][6][7][8][9]. The key component of the reactor is a membrane-electrode-assembly (MEA), composed of catalytic precious metal powders for the anode and cathode that are hot-pressed as thin (fixedbed) films onto the opposing surfaces of a Nafion Ò cationexchange membrane (Nafion is a registered trademark of E. I.…”

Production of Low‐trans Fatty Acids Edible Oil by Electrochemical Hydrogenation in a Diaphragm Reactor Under Controlled Conditions

“…Compared with other types of catalytic hydrogenation, electrochemical hydrogenation is regarded as a more efficient modification of the gas hydrogenation process. Electrochemical hydrogenation of oils at low operating temperatures (\70°C) has been extensively investigated, and TFAs can be reduced to less than 10% of the oil content while increasing selectivity for unsaturated fatty acids [6][7][8].…”