SYNTHESIS OF METHYL TERT-BUTYL ETHER ON SULFUR-PROMOTED ZRO2

The synthesis of methyl tert-butyl ether (MTBE) from methanol and isob utylene in a gas-solid heterogeneous system over sulfur-promoted zirco nias calcined at different temperatures between 400 and 700 degrees C was studied. The reaction temperature was varied in the range 90-110 d egrees C, and methanol to isobutylene molar ratios were changed from 1 .0 to 1.3. The catalyst acidity was a direct function of the sulfur lo ad, in turn a consequence of the calcination temperature. Temperature programmed reduction experiments allowed us to observe that the sulfur reduction process is different according to the calcination temperatu re. The highest activity was observed on the sample calcined at 600 de grees C, which was comparable with that of the reference catalyst Ambe rlyst 15 under the same conditions. A direct relationship between cata lyst acidity and conversion was not observed. The injection of water c ompletely poisoned the catalyst activity in a reversible manner. (C) 1 997 Elsevier Science S.A.