VAPOR-PHASE ESTERIFICATION CATALYZED BY IMMOBILIZED DODECATUNGSTOSILICIC ACID (SIW12) ON ACTIVATED CARBON

The vapor phase esterification of acetic acid with ethanol and n-butan ol catalyzed by SiW12 supported on activated carbon was studied in a f low fixed-bed reactor in the range of 358 to 433 K. The effects of the reaction temperature, liquid hourly space velocity (LHSV) as well as the molar ratio on the catalytic activity have been investigated. The kinetic studies showed that the rate of esterification was dependent o n the partial pressures of the reactants and the addition of argon, an inert diluent in the system when the total pressure was kept at 1 atm . Also the alcohol structure has a profound effect on not only the rat e of esterification, but also on the mechanism of esterification chang ing from a dual site mechanism for ethanol to a single site mechanism for n-butanol.