Process for dealkylation and recovery of hydrogen from refinery gases

Claim 1

A HYDRODEALKYLATION OPERATION WHEREIN TOLUENE IS HYDRODEALKYLATED TO PRODUCE BENZENE WHICH COMPRISES HYDRODEALKYLATING TOLUENE IN A HYDRODEALKYLATION REACTION ZONE IN THE PRESENCE OF HYDROGEN, RECOVERING BENZENE FROM THE REACTION ZONE EFFLUENT, RECOVERING A GASEOUS STREAM CONTAINING HYDROGEN, UNREACTED TOLUENE, METHANE, ETHANE AND SOME BENZENE AND PASSING THE SAME TO A HEAT EXCHANGER, THEREIN COOLING SAID STREAM TO LIQUEFY A PORTION THEREOF, SEPARATING AS A LIQUID FROM SAID STREAM HYDROCARBONS BOILIN HIGHER THAN METHANE, FURTHER COOLING NOW-REMAINING GBASEOUS STREAM TO LIQUEFY A SUBSTANTIAL PORTION OF METHANE THEREIN CONTAINED, SEPARATING A LIQUEFIED METHANE STREAM FROM THE THUS-COOLED REMAINING GASES, EXPANDING TH LIQUEFIED METHANE STREAM AND USING THE EXPANDED LIQUEFIED METHANE STREAM TO COOL THE INCOMING GASES, AS WELL AS SAID REMAINING GASES; RECOVERING HYDROGEN-CONTAINING GASES FROM THE SEPARATION OF THE LIQUEFIED METHANE STREAM FROM THE COOLED REMAINING GASES, AND PASSING SAID HYDROGEN, WITHOUT PRESSURE REDUCTION INTO HEAT EXCHAGE WITH THE INCOMING GASES AND SAID REMAINING GASES, AND THENCE TO SAID REACTION ZONE AS THE HYDROGEN USED IN THE HYDRDEALKYLATION OPERATION EFFECTED IN SAID REACTION ZONE; AND RECOVERING METAHNE FROM THE OPERATION.