Active zeolite catalysts of improved stability for producing gasoline from methanol

摘要

A feedstock of low molecular weight oxygenates such as methanol and/or dimethylether is contacted with a mildly presteamed or hydro-thermally treated zeolite catalyst in a reaction zone to produce liquid hydrocarbons in the gasoline boiling range. The pretreated zeolite catalyst has an alpha -value (acid cracking activity) substantially the same as the alpha -value of fresh unsteamed catalyst and shows increased stability and resistance to aging under oxygenate conversion conditions of elevated temperature and pressure.