Cascaded pretreater for removal of nitrogen

Claim 1

IN THE METHOD FOR REFORMING IN CONTACT WITH A NITROGEN-SENSITIVE SOLID CATALYST A STRAIGHT RUN NAPHTHA IN ADMIXTURE WITH A THERMAL NAPHTHA WHICH INITIALLY CONTAINS A RELATIVELY HIGH CONCENTRATION OF ORGANIC NITROGEN COMPOUNDS EQUIVALENT TO AT LEAST ABOUT 30 P.P.M. NITROGEN, THE IMPROVEMENT WHICH COMPRISES CONTACTING IN AN AUXILIARY REACTION ZONE SAID NITROGEN CONTAINING THERMAL NAPHTHA WITH HYDROGEN IN THE PRESENCE OF A NITROGENINSENSITIVE CATALYST UNDER SEVERE HYDRODENITROGENIZING CONDITIONS WHEREBY THE CONTENT OF ORGANIC NITROGEN COMPOUNDS WITHIN THE BOILING RANGE OF SAID THERMAL NAPHTHA IS SUBSTANTIALLY REDUCED, MIXING THE EFFLUENT FROM SAID AUXILIARY REACTION ZONE WITH A MAJOR PROPORTION OF SAID STRAIGHT RUN NAPHTHA, CONTACTING IN A PRIMARY REACTION ZONE SAID MIXTURE WITH HYDROGEN IN THE PRESENCE OF A NITROGEN-SENSITIVE SOLID CATALYST UNDER CONDITIONS LESS SEVERE THAN IN SAID AUXILIARY REACTION ZONE TO OBTAIN A PRIMARY REACTION ZONE EFFLUENT COMPRISING C1+ HYDROCARBONS, HYDROGEN, AND HYDROGEN COMPOUNDS OF NITROGEN AND SULFUR DERIVED FROM THE ORGANIC NITROGEN AND SULFUR COMPOUNDS PRESENT IN SAID THERMAL NAPHTHA AND STRAIGHT RUN NAPHTHA, SEPARATING SAID EFFLUENT INTO PLURALITY OF FRACTION INCLUDING A C5+ HYDROCARBON FRACTION OF SUBSTANTIALLY REDUCED NITROGEN CONTENT AND REFORMING SAID C5+ HYDROCARBON FRACTION IN CONTACT WITH A NITROGENSENSITIVE SOLID CATALYST.