Catalytic conversion process and apparatus with improved temperature control of the reaction

Claim 1

A PROCESS FOR THE CATALYTIC REFORMING OF LOW ANTIKNOCK RATING NAPHTHAS WHICH COMPRISES PROVIDING A PLURALITY OF SUPERIMPOSED CATALYTIC REFORMING ZONES AND AN ELONGATED SEALING ZONE OF RESTRICTED CROSS SECTION ADAPTED TO THE FLOW OF CATALYST WHILE RESTRICTING THE FLOW OF VAPOR THERETHROUGH INTERPOSED BETWEEN ADJACENT REFORMING ZONES, PASSING A MOVING BED OFF COMPACT UNFLUIDIZED REFORMING CATALYST DOWNWARDLY BY GRAVITY SUCCESSIVELY THROUGH SAID REFORMING AND SEALING ZONES AT A CATALYST TO NAPHTHA RATIO OF BETWEN ABOUT 0.2 AND ABOUT 1.50 POUNDS PER POUND, PASSING A COUNTERCURRENT FLOW OF NAPHTHA VAPOUR AND BETWEEN ABOUT 2000 S.C.F. AND ABOUT 6000 S.C.F. OF A HYDROGEN-CONTAINING RECYCLE GAS PER BARREL TWEEN ABOUT 850*F. AND ABOUT 950*F. AND A PRESSURE OF BETWEEN ABOUT 250 P.S.I.G. AND ABOUT 800 P.S.I.G. UPWARDLY SUCCESSIVELY THROUGH SAID REFORMING ZONES IN EACH OF WHICH A TEMPERATURE DECREASE OCCOURS DUE TO ENEACH OF WHICH A TEMPERATURE DECREASE OCCURS DUE TO ENDOTHERMIC AROMATRIZATION AND REFORMING REACTIONS TAKING PLACE THEREIN, PASSING A MINOR PORTION OF THE THUS COOLED REACTANT VAPOR FROM ALL BUT THE UPPERMOST OF SAID PLURALITY OF REFORMING ZONES THROUGH THE NEXT SUPERJACENT SEALING ZONE INTO THE NEXT SUPERJACENT REFORMING ZONE THERE BY ESTABLISHING AND MAINTAINING A PRESSURE DIFFERENTIAL THEREIN SUFFICIENT TO FORCE A MAJOR PORTION OF SAID COOLED REACTANT VAPOR FROM EACH OF THE SAME REFORMING ZONES INTO AND THROUGH AN INTERHEATER ZONE EXTERNAL TO SAID REFORMING ZONE, REHEATING SIAD MAJOR PORTION OF REACTANT VAPOR IN SAID INTERHEATER ZONE OUT OF CONTACT WITH SAID REFORMING CATALYST TO AT LEAST FULLY COMPENSATE FOR THE TEMPERATURE DECREASE OCCURING IN THE REFORMING ZONE FROM WHICH SAID MAJOR PORTION WAS REMOVED, FLOWING THE REHEATED MAJOR PORTION UNDER THE INFLUENCE OF SAID PRESSURE DIFFERENTIAL INTO CONTACT WITH THE REFORMING CATALYST IN THE NEXT SUPERJACENT REFORMING ZONE FOR ADMIXTURE WITH SAID MINOR PORTION AND SUBSEQUENT PASSAGE OF THE COMBINED REHEATED REACTANT VAPOR STREAM THROUGH SAID NEXT SUPERJACENT REFORMING ZONE, REMOVING THE REACTED VAPOR STREAM FROM THE UPERMOST OF SAID PLURALITY OF REFORMING ZONES AS A REACTOR EFFLUENT, COOLING AND PARTIALLY CONDENSING SAID EFFLUENT, SEPARATING THE CONDENSED PHASE FROM THE UNCONDENSED PHASE OF SAID EFFLUENT, FRACTIONATING THE CONDENSED PHASE TO PRODUCE REFORMED AROMATIC HYDROCARBON-CONTAINING HIGH ANTI-KNOCK NAPHTH STREAM OF DESIRED BOILING RANGE, SEPARATING A SUBSTANTIAL PROPORTION OF THE HYDROCARBONS AS A GAS PRODUCT FROM SAID UNCONDENSED PHASE LEAVING SAID HYDROGEN-CONTAINING RECYCLE GAS, AND RECIRCULATING AT LEAST A PART OF SAID RECYCLE GAS FOR PASSAGE WITH FURTHER QUANTITIES OF SAID LOW ANTIKNOCK RATING NAPHTHA THROUGH SAID REFORMING ZONES.