The Hydrogenation of Fats and Oils

Poisoning is not always bad. There are situations where a catalyst is intentionally poisoned to decrease activity towards an undesirable reaction. In the hydro-desulfurization and -demetallization of a petroleum feedstock the catalyst is presulfided prior to introducing the feed to decrease its activity and minimize cracking reactions that will produce unwanted gases. Another is the use of ammonia to slightly poison a Pt catalyst used in the hydrogenation of fats and oils to decrease undesirable oversaturation. 

The hydrogenation of fats and oils is a very old technology. It was invented in... 

Formation of the high-melting unsaturated fats or isomerization accompanies hydrogenation and appears to be in proportion to the selectivity of the reaction. Therefore, compromises must be made between selectivity and isomer formation when determining the best hydrogenation conditions for the various basestocks. Control of the operating variables that affect the hydrogenation of fats and oils is necessary to produce the desired product functionality (Calsicat, 1992). 

Several examples of research and development in conducting hydrogenations in SCF media are included herein. In one of the earliest papers on this topic (11), Pickel and Steiner report application of a continuous fixed-bed reactor using supercritical CO2, ethane, and propane for an unspecified hydrogenation reaction of pharmaceutical interest. Other applications include the hydrogenation of fats and oils for the food industry, demonstration of hydrogenation of a variety of organic substrates, and enantioselective synthesis. 

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