The electrocatalytic hydrogenation of soybean oil

Soybean oil has been hydrogenated electrocatalytically at a moderate temperature, without an external supply of pressurized H₂ gas. In the electrocatalytic reaction scheme, atomic hydrogen is produced on an active Raney nickel powder cathode surface by the electrochemical reduction of water molecules from the electrolytic solution. Adsorbed hydrogen then reacts with an oil’s triglycerides to form a hydrogenated product. Experiments were carried out at 70°C with a flow-through electrochemical reactor operating in a batch recycle mode. The reaction medium was a two-phase mixture of soybean oil in a water/t-butanol solvent containing tetraethylammoniump-toluenesulfonate as the supporting electrolyte. In all experiments the reaction was allowed to continue for sufficient time to synthesize a brush hydrogenation product. The effects of oil content, applied current, solvent composition, and supporting electrolyte concentration on the efficiency of hydrogen addition to the oil and on the chemical properties of the hydrogenated oil product were determined. The electrohydrogenated oil is characterized by a high stearic acid content and a low percentage of totaltrans isomers, as compared to that produced in a traditional hydrogenation process.