Heterogeneously-catalyzed glycerolysis of fatty acid methyl esters: reaction parameter optimization.

C. A. FERRETTI; R.N. OLCESE; C.R. APESTEGUÍA; J.I. DI COSIMO

INDUSTRIAL & ENGINEERING CHEMICAL RESEARCH

American Chemical Society

Año: 2009 vol. 48 p. 10387 - 10394

0888-5885

The synthesis of glycerol monoesters (monoglycerides) by fatty acid methyl ester glycerolysis is efficiently achieved on MgO catalysts, thereby offering an alternative technology to the current commercial processes that use environmentally unfriendly liquid bases. Our results show that on MgO the heterogeneous monoglyceride synthesis is a four-phase reaction that may be conducted in kinetic control regime and produces high monoglyceride yields provided that appropriate operative conditions were used, namely: relatively high stirring rates (500-700 rpm), temperatures between 490 and 530 K, glycerol/methyl oleate ratios higher than one, and mean catalyst particle sizes of up to 250 µm.  In particular, oleic acid methyl ester glycerolysis on MgO at 523 K gave in 2h monoglyceride yields of 75 %, a value higher than that those typically obtained via the homogeneously-catalyzed process (60 %). Regarding the heterogeneous process selectivity, the á-isomer is the main monoglyceride isomer obtained under the reaction conditions noted above. Moreover, no triglycerides are formed, being 1,2 and 1,3-diglycerides the only reaction byproducts.