Control of CO emissions in a process for producing gasoline from methanol

Claim 1

In a process for the catalytic conversion of methanol to produce products boiling in the motor fuel range, wherein said methanol is contacted with a porous acidic solid catalyst comprising a crystalline aluminosilicate zeolite having a pore diameter greater than about 5 Angstroms, a silica-to-alumina ratio of at least 12, and a constraint index within the range of 1-12 at elevated temperatures, in a reaction vessel at conversion conditions including elevated temperatures and the absence of added hydrogen so as to convert said methanol to lower molecular weight products with deposit on said catalyst of a deactivating solid carbonaceous contaminant resulting from said conversion, the so deactivated catalyst being transferred to a regeneration vessel in which oxidation of said carbonaceous deposit proceeds in the presence of air with generation of carbon monoxide and carbon dioxide and the regenerated catalyst at elevated temperature is transferred from said regeneration vessel to said reaction vessel to catalyze further conversion, the improvement which comprises: conducting said conversion and said regeneration with an inventory of said solid, porous, acidic solid catalyst particles and particles of an oxidation catalyst selected from the group consisting of copper chromite, cobalt chromite, or mixtures thereof and limiting the concentration of said oxidation catalyst to an amount great enough to promote oxidation of CO and inadequate to substantially affect the dealkylation of aromatics in said reaction vessel as compared with a like catalyst free of such metal, said amount being less than 500 ppm based on total catalyst inventory.