Naphtha reforming and recycle gas system

Claim 1

IN A CONTINUOUS HYDROCARBON CONVERSION PROCESS WHEREIN A HYDROCARBON FEED IS CONTACTED IN A CONVERSION ZONE WITH A CATALYST AND HYDROGEN-CONTAINING GAS AT AN ELEVATED TEMPERATURE TO PRODUCE VAPOROUS REACTION PRODUCTS, THE IMPROVEMENT WHICH COMPRISES CONTACTING SAID VAPOROUS REACTION PRODUCTS LEAVING SAID HYDROCARBON CONVERSION ZONE WITH A MOLECULAR SIEVE MATERIAL CONTAINED IN A FIRST SIEVE ZONE TO SELECTIVELY ADSORB ONE GROUP OF HYDROCARBONS PRESENT IN THE VAPOROUS REACTION PRODUCTS, COOLING AT LEAST PART OF THE UNADSORBED VAPOROUS REACTION PRODUCTS TO CONDENSE NORMALLY LIQUID HYDROCARBONS, SEPARATING HYDROGEN-RICH GAS FROM SAID LIQUID HYDROCARBONS, RECOVERING THE SEPARATED LIQUID HYDROCARBONS AS PRODUCT, PASSING THE SEPARATED HYDROGEN RICH GAS OVER SPENT MOLECULAR SIEVE MATERIAL CONTAINED IN A SECOND SIEVE ZONE PREVIOUSLY USED IN A SELECTIVE ADSORPTION STEP FOR THE SAME TYPE OF REACTION PRODUCTS TO DESORB SELECTIVELY ADSORBED HYDROCARBONS THEREFROM AND CARRYING OUT THE DESORPTION STEP AT A HIGHER TEMPERATURE THAN SAID ADSORPTION STEP, CHARGING THIS MIXTURE OF DESORBED HYDROCARBONS AND HYDROGEN RICH GAS ALONG WITH FRESH HYDROCARBON FEED TO SAID HYDROCARBON CONVERSION ZONE, CONTINUING THIS PROCEDURE UNTIL THE ADSORPTIVE POWER OF THE MOLECULAR SIEVE MATERIAL IN THE FIRST SIEVE ZONE IS SUBSTANTIALLY SPENT AND EXCHANGING SAID SIEVE ZONES AND PROCEEDING WITH THE PROCESS AS AFOREMENTIONED.