Overcoming mass-transfer limitations in partial hydrogenation of soybean oil using metal decorated polymeric membranes

Abstract

The conventional soybean oil hydrogenation process (metal catalyst on solid support particles slurried in oil, H2 bubbled through the oil) is compared to metal-decorated integral-asymmetric polyetherimide (PEI) membranes, as far as changes in temperature and pressure are concerned. Using metal decorated-polymeric membranes, H2 is supplied to the catalytic sites by permeation from the membrane substructure. As opposed to the slurry process, metal-decorated membranes show only slightly increased trans fatty acid (TFA) formation when the temperature is raised (50-90°C) to accelerate the process. This is likely due to the efficient and to some extent self-regulating H2 supply directly to the catalytic sites on the membrane skin. The hydrogenation rate and TFA formation of the metal decorated membrane process show a minor dependence on pressure.