Hydrocarbon conversion process including acidic zeolite reactivation

Claim 1

In a hydrocarbon conversion process in which a hydrocarbon is subjected to contact with an acidic intermediate or large pore size zeolite catalyst to produce conversion products and in which the catalyst undergoes a significant loss in acid catalytic activity as a result of accumulating carbonaceous matter during the conversion, the improvement comprising: subjecting the zeolite catalyst with the accumulated carbonaceous material to a burning operation in the presence of an oxygen-containing gas to remove at least a major part of the accumulated carbonaceous material, contacting the catalyst with an effective amount of an aqueous liquid solution of an alkali metal carbonate and/or aqueous alkaline earth metal carbonate at a temperature from 100° to 370° C. for a period of from 1 to 24 hours, subjecting the catalyst to ammonium ion exchange followed by calcination to convert the zeolite to the hydrogen form, under conditions sufficient to restore at least a significant amount of the acid catalytic activity of the fresh zeolite prior to reusing the catalyst in the conversion process.