SELECTIVITY BEHAVIOR DURING THE EQUILIBRIUM-LIMITED HIGH-TEMPERATURE FORMATION OF MTBE ON ACID ZEOLITES

The synthesis of MTBE was studied in the gas phase at elevated temperatures (up to 175-degrees-C) and low pressures (150 kPa) where the MTBE formation rate is limited by thermodynamic equilibrium, using various solid acid catalysts (Amberlyst-15 resin, silica-alumina, HY and H-ZSM-5 zeolites). All the zeolites studied were found to exhibit better selectivities to MTBE than the commercially used Amberlyst-15 resin catalyst. The formation of by products increased with increasing temperature and appeared to have a strong enhancing effect on catalyst deactivation. H-ZSM-5 seems to be more suitable for high temperature formation of MTBE because of its excellent selectivity towards MTBE and low deactivation behavior.