Convenient and Environmentally Friendly Production of Isostearic Acid with Protonic Forms of Ammonium Cationic Zeolites

Abstract

Three ammonium-cationic zeolites (ferrierite, ZSM5, and zeolite β) are individually analyzed to produce branched-chain fatty acid (i.e., isostearic acid) from unsaturated linear-chain fatty acid (ulc-FA) with up to 98% conversion and 80% selectivity. The SiO₂/Al₂O₃ molar ratio of zeolite, amount of water and choice of additive are found to be the key factors for the efficiency of zeolites in this particular reaction. Detailed characterization of zeolites supports the optimization parameters to produce the best results. Large scale production of isostearic acid achieving a 76% selectivity and 96% conversion demonstrates the potential of this systems' capability at the pilot scale. Variation in isomeric composition of branched-chain fatty acid (bc-FA) product is observed for the three different catalytic methods. Dimer production due to interaction with the external acidic surface of these zeolites has been observed, but it can be suppressed.

http://ift.tt/2x16q9Q