Abstract: Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst system comprising a zeolite having the topology of ZSM-5 and a zeolite sorbing 10 to 40 mg 3-methylpentane at 90.degree. C., 90 torr, per gram dry zeolite in the hydrogen form, e.g., ZSM-22, ZSM-23, or ZSM-35. The treatment over the acidic catalyst system in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha.

Abstract: Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst comprising a zeolite sorbing 10 to 40 mg 3-methylpentane at 90.degree. C., 90 torr, per gram dry zeolite in the hydrogen form, e.g., ZSM-22, ZSM-23, or ZSM-35. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. The use of the specified zeolite provides greater desulfurization, gasoline selectivity, and octane than obtained using ZSM-5.