Hydrodealkylation

Claim 1

THE PROCESS OF DEALKYLATING ALKYLATED AROMATIC HYDROCARBONS AT A CONVERSION RATE OF AT LEAST 60% PER PASS TO PRODUCE AROMATIC HYDROCARBONS OF A LOWER MOLECULAR WEIGHT WHICH COMPRISES CONTACTING THE ALKYLATED AROMATIC HYDROCARBONS IN A REACTION ZONE AT A TEMPERATURE BETWEEN 1100*F. AND 1500*F. AND AT A PRESSURE BETWEEN ABOUT 500 P.S.I.G. AND 800 P.S.I.G. WITH A HYDROGEN RICH GAS, SAID CONTACTING BEING CARRIED OUT IN THE SUBSTANTIAL ABSENCE OF SOLIDS OR SURFACES WHICH WOULD TENT TO CATALYZE THE REACTION, QUENCHING THE REACTION WITH HYDROGEN TO MAINTAIN A TEMPERATURE DIFFERENT IN THE REACTION ZONE BETWEEN MAXIMUM AND MINIMUM REACTION TEMPERATURES OF NOT TO EXCEED ABOUT 200*F., COOLING THE REACTION EFFLUENT FROM THE REACTION ZONE TO STOP THE REACTION, SEPARATING UNREACTED ALKYLATED AROMATIC HYDROCARBONS AND IMPURE HYDROGEN FROM THE REACTION EFFLUENT, RETURNING THE UNREACTED ALKYLATED AROMATIC HYDROCARBONS BACK TO THE REACTION ZONE TO INCREASE THE ULTIMATE YIELD OF AROMATIC HYDROCARBONS, AND PASSING IMPURE FEED HYDROGEN IN COUNTERCURRENT CONTACT WITH ALKYLBENZENE AT TEMPERATURES BELOW AMBIENT THEREBY REMOVING HYDROCARBONS AND REDUCING HYDROGEN CONSUMPTION IN THE REACTION ZONE.