Mesoporous sulfonic acids as selective heterogeneous catalysts for the synthesis of monoglycerides

Glycerol was esterified with an equimolar amount of lauric acid to monolaur in using zeolites, sulfonic resins, and sulfonic mesoporous materials as ca talysts. The latter were obtained by immobilization of 3-mercaptopropyl gro ups and oxidation with H2O2. In particular, fatty acid conversions, monogly ceride yields, and selectivities obtained with mesoporous (ordered, amorpho us) sulfonic catalysts were compared with those of other heterogeneous or h omogeneous catalysts. When using silica gel coated with propylsulfonic acid s, high reaction rates are coupled to high monoglyceride yields, e.g., 53% mono yield for a 1:1 glycerol:lauric acid ratio. Minimizing the autocatalyt ic contribution of the fatty acid reactant is a critical issue. The influen ce of a number of reaction parameters is investigated. The mesoporous sulfo nic catalysts are also employed in the esterification of propanediols and m eso-erythritol, and for reactions with other fatty acids. (C) 1999 Academic Press.