Patent GB-790493-A (GB)
Title: Process for regenerating platinum catalyst in a reforming process
IPC: B01J23/96
Filed: 1955-04-27
Abstract: In a hydrocarbon reforming process in which vaporized hydrocarbon and hydrogen are passed into a reaction zone containing a bed of platinum catalyst, the catalyst is regenerated by a process comprising the following steps: (a) treatment with hydrogen-containing gas to remove hydrocarbons; (b) passage of a purge gas substantially free from hydrogen, carbon oxides and oxygen to remove hydrogen; (c) introducing combustion-supporting gas to burn off carbonaceous deposits at a temperature not above 1100 DEG  F.; (d) purging with a gas substantially free from hydrogen, carbon oxides and oxygen to remove the combustion-supporting gas; (e) treatment with hydrogen-containing gas.  In this way simultaneous contact of hydrogen and carbon dioxide with the catalyst is prevented.  The purge gas may be steam, nitrogen, or helium, but preferably is flue gas which has been scrubbed with a solution of caustic alkali to remove carbon dioxide.  The flue gas may result from burning methane or natural gas, or it may be the gas obtained from step (c).  After step (b) flue gas which has not been scrubbed may be passed over the catalyst.  The combustion-supporting gas may be formed by adding oxygen or air to scrubbed or unscrubbed flue gas used in the previous step.  Step (c) may be followed by treatment at elevated temperature with a gas having an oxygen partial pressure of at least 1 atmosphere. The preferred catalyst is platinum supported on gamma alumina derived from boehmite.  The reforming process described involves treatment of naphthenic hydrocarbons boiling at 150-500 DEG F. at a reactor inlet temperature of 850-1000 DEG  F. and a pressure of 50-700 lb. per sq. in.  The liquid space velocity may be 1-4 V/V/Hr. and the amount of hydrogen 1000-10,000 cubic feet per barrel of feed.ALSO:In a hydrocarbon reforming process in which vaporized hydrocarbon and hydrogen are passed into a reaction zone containing a bed of platinum catalyst (see Group IV (b)), the catalyst is regenerated by a process comprising the following steps: (a) treatment with hydrogen-containing gas to remove hydrocarbons; (b) passage of a purge gas substantially free from hydrogen, carbon oxides, and oxygen to remove hydrogen; (c) introducing combustion-supporting gas to burn off carbonaceous deposits at a temperature not above 1100 DEG  F.; (d) purging with a gas substantially free from hydrogen, carbon oxides, and oxygen to remove the combustion-supporting gas; (e) treatment with hydrogen-containing gas.  In this way simultaneous contact of hydrogen and carbon dioxide with the catalyst is prevented.  The purge gas may be steam, nitrogen or helium, but preferably is flue gas which has been scrubbed with a solution of caustic alkali to remove carbon dioxide.  The flue gas may result from burning methane or natural gas, or it may be the gas obtained from step (c).  After step (b) flue gas which has not been scrubbed may be passed over the catalyst.  The combustion-supporting gas may be formed by adding oxygen or air to scrubbed or unscrubbed flue gas used in the previous step.  Step (c) may be followed by treatment at elevated temperature with a gas having an oxygen partial pressure of at least 1 atmosphere.  The preferred catalyst is platinum supported on gamma alumina derived from boehmite.