Method and apparatus for the catalytic reforming of naphthas in series

Claim 1

IN A PROCESS FOR CATALYTICALLY REFORMING A NAPHTHA HYDROCARBON CHARGE STOCK WHEREIN A NAPHTHA HYDROCARBON STREAM AND HYDROGEN ARE PASSED THROUGH A SERIES OF REACTION ZONES CONTAINING SEPARATE FIXED BEDS CONTAINING GIVEN AMOUNTS OF A PLATINUM-CONTANING CATALYST UNDER REFORMING CONDITIONS OF TEMPERATURE, PRESSURE, SPACE VELOCITY AND HYDROGEN TO HYDROCARBON RATIO, HEATING THE NAPHTHA HYDROCARBON STREAM TO REFORMING TEMPERATURE PRIOR TO ITS INTRODUCTION TO EACH OF SAID ZONES, THE IMPROVEMENT WHICH COMPRISES CONTINUING THE REFORMING UNTIL THERE IS DECREASE IN HYDROCARBON CHARGE NAPHTENE CONTENT AND THEN PASSING THE NAPHTHA HYDROCARBON STREAM THROUGH A LESSER PORTION OF SAID GIVEN AMOUNT OF CATALYST IN AT LEAST THE LAST REACTION ZONE TO OPTIMIZED WEIGHT HOURLY SPACE VELOCITY FOR MAXIMUM LIQUID PRODUCT YIELD WHILE MAINTAINING THE OPERATING CONTINUITY OF THE PROCESS, INTRODUCING RECYCLY GAS FROM SAID REFORMING PROCESS TO THE PORTION OF CATALYST THROUGH WHICH THE NAPHTHA STREAM IS NOT FLOWING, SAID LESSER PORTION OF CATALYST IN AT LEAST THE LAST REACTION ZONE BEING EQUAL TO (FR/WHSV)-"K, WHERE FR IS THE NAPHTHA FEED RATE BEING EMPLOYED, WHSV IS THE PREDETERMINED OPTIMUM WEIGHT HOURLY SPACE VELOCITY AND CK IS THE QUANTITY OF CATALYST CONTAINED IN ALL THE REACTION ZONES OTHER THAN THOSE IN WHICH THE QUANTITY OF CATALYST THROUGH WHICH THE NAPHTHA STREAM FLOWS IS BEING VARIED.