ABSTRACT
The condensation of glycerol with acetone was performed using silicotungstic acid (SiW) immobilized in SBA-15, at 70°C. The main product of glycerol acetalization was solketal. Different techniques were used to characterize the catalysts. A series of catalysts with different heteropolyacid loading were prepared. It was observed that the catalytic activity increases with the amount of SiW immobilized in SBA-15, being the SiW2@SBA-15 (with 7.8 wt.%) the most active sample. All catalyst exhibited good values of selectivity to solketal (about 99% near complete conversion). To optimize the reaction conditions, the effect of different reaction parameters (catalyst loading, molar ratio of glycerol to acetone and temperature), on the glycerol acetalization over the SiW2@SBA-15 catalyst, was studied. Catalytic stability of the SiW2@SBA-15 was evaluated by performing consecutive batch runs with the same catalyst sample. It was observed that, after the third use, the catalytic activity stabilized.
