Naphtha hydrofining to remove nitrogen

Claim 1

A HYDROFINING PROCESS FOR PREPARING CATALYTIC REFORMER FEED CONTAINING LESS THAN 1 P.P.M. NITROGEN FROM OLEFINIC NAPHTHA CONTAINING NITROGEN COMPOUNDS IN CONCENTRATION DELETERIOUS TO PLATIUM REFORMING CATALYSTS, SAID NAPHTHA CONTAINING AT LEAST 20% BY VOLUME OLEFINS SUCH THAT EXOTHERMIC REACTIONS INCLUDING HYDROGENATION OF OLEFINS WILL CAUSE A TEMPERATURE RISE GREATER THAN 75*F. WHEN NAPHTHA AND HYDROGEN ARE PASSED INTO CONTACT WITH A HYDROFINING CATALYST AT REACTION CONDITIONS INCLUDING A TEMPERATURE INITIALLY ABOVE 550*F. AND A PRESSURE BETWEEN 300 AND 1000 P.S.I.G., WHICH PROCESS COMPRISES THE STEPS: (1) PASSING A PREHEATED MIXTURE OF SAID OLEFINIC NAPHHA AND AT LEAST SUFFICIENT EXCESS HYDROGEN TO MAINTAIN SAID NAPHTHA TOTALLY VAPORIZED AT SAID REACTION CONDITIONS INTO CONTACT WITH A HYDROFINING CATALYST AT AN INLET TEMPERATURE SUFFICIENTLY ABOVE 550*F. SUCH THAT THE TEMPERATURE INCREASES TO ABOVE 700* F. DURING SAID CONTACTING; (2) COOLING THE MIXTURE OF HYDROGEN AND PARTIALLY HYDROFINED NAPHTHA EFFLUENT OF SAID CONTACTING BY AT LEAST 50*F. TO A TEMPERATURE BETWEEN 575*F. AND 700*F., SAID NAPHTHA REMAINING TOTALLY VAPORIZED; (3) PASSING THE COOLED MIXTURE OF HYDROGEN AND PARTIALLY HYDROFINED NAPHTHA INTO CONTACT WITH A HYDROFINING CATALYST OF SEVERAL-FOLD HIGHER ACTIVITY FOR DENITRIFICATION THAN COBALT-MOLYBDENUM HYDROFINING CATALYST, USING AS A STANDARD THE COBALT-MOLYBDENUM CATALYST DESCRIBED IN EXAMPLE 1 OF THE FOREGOING SPECIFICATION, TO CONVERT DELETERIOUS NITROGEN COMPOUNDS REMAINING IN SAID PARTIALLY HYDROFINED NAPHTHA SUBSTANTIALLY COMPLETELY TO AMMONIA, THE COOLING IN STEP (2) ABOVE BEING TO A TEMPERATURE SUFFICIENTLY BELOW 700*F. SUCH THAT THE MAXIMUM TEMPERATURE DOES NOT EXCEED 700*F. DURING CONTACTING WITH THE HIGHER ACTIVITY CATALYST; AND (4) REMOVING THE AMMONIA RESULTING FROM THE CONTACTING OF THE ABOVE STEPS (1) AND (3) FROM THE EFFLUENT OF THE SECOND-MENTIONED CONTACTING.