Pebble circulating reaction system

Claim 1

A PROCESS FOR EFFECTING DEALKYLATION OF AN ALKYLATED AROMATIC WHICH COMPRISES PASSING A FEED STOCK COMPRISING AN ALKYLATED AROMATIC HYDROCARBON AND HYDROGEN IN VAPOR PHASE TO THE LOWER PORTION OF A PREHEAT ZONE, FLOWING SAID FEED STOCK UPWARDLY THROUGH SAID PREHEAT ZONE COUNTERCURRENTLY TO A FIRST MASS OF DOWNWARDLY MOVING HEATED PEBBLES CONTAINED WITHIN SAID PREHEAT ZONE WHILE ABSORBING SUFFICIENT HEAT THEREFROM TO RAISE THE TEMPERATURE OF THE FEED STOCK TO A POINT AT WHICH THE HYDROGEN AND THE ALKYLATED AROMATIC HYDROCARBON WILL EXOTHERMICALLY INTERREACT TO FORM A DEALKYLATED AROMATIC HYDROCARBON, DISENGAGING SAID FEED STOCK FROM SAID FIRST MASS OF PEBBLES AND PASSING IT TO A REACTION ZONE, REACTING SAID FEED STOCK IN SAID REACTION ZONE FOR A PERIOD OF TIME SUFFICIENT TO AT LEAST PARTIALLY CONVERT THE ALKYLATED AROMATIC HYDROCARBON COMPONENT OF THE FEED TO AN AROMATIC HYDROCARBON HAVING AT LEAST ONE LESS ALKYL GROUP ATTACHED THERETO THAN THE ALKYL AROMATIC HYDROCARBON IN THE FEED STOCK, PASSING THE REACTION PRODUCTS TOGETHER WITH UNCONVERTED COMPONENTS OF THE FEED TO THE LOWER PORTION OF A COOLING ZONE, FLOWING SAID UNCONVERTED FEE COMPONENTS AND REACTION PRODUCTS UPWARDLY CONTERCURRENTLY TO A SECOND DOWNWARDLY MOVING MASS OF RELATIVELY COOL PEBBLES CONTAINED WITHIN SAID COOLING ZONE WHILE IMPARTING HEAT THERETO IN AN AMOUNT SUFFICIENT TO RAISE THE TEMPERATURE OF THE PEBBLES IN THE LOWER PART OF THE COOLING ZONE TO A TEMPERATURE APPROACHING THAT OF THE REACTION PRODUCTS, RECOVERING SUBSTANTIALLY COOLED UNREA CHED FEED COMPONENTS AND REACTION PRODUCTS FROM THE UPPER PORTION OF SAID COOLING ZONE, CONTINUOUSLY PASSING PEBBLES FROM THE BOTTOM OF SAID FIRST MASS TO THE TOP OF SAID SECOND MASS, AND CONTINUOUSLY PASSING PEBBLES FROM THE BOTTOM OF SAID SECOND MASS TO THE TOP OF SAID FIRST MASS, THE HEAT REQUIRED TO RAISE THE FEED FROM THE TEMPERATURE AT WHICH IT ENTERS THE PREHEAT ZONE TO THE REACTION TEMPERATURE BEING SUPPLIED BY THE HEAT GIVEN OFF BY THE OXETHERMIC REACTION OF ALKYL AROMATIC HYDROCARBON WITH HYDROGEN IN THE REACTION ZONE.