| 摘要 |
Method for the regeneration of a catalytically active coating on the inner surface of a gap tube which was previously used in a gap tube furnace to generate ethylene-containing cracked gas, wherein the cracked gas is maintained in the gap tube at a cracked gas discharge temperature in the range from 750 through 1000 ºC by thermal fission of a hydrocarbon or a hydrocarbon mixture in the presence of steam, characterized in that an oxygen-containing gas mixture is initially supplied through the gap tube at a temperature in the range from 600 to 1000 ºC (step a), wherein a partial or complete removal of carbon-containing deposits takes place, and afterwards, at a temperature in the range from 500 to 850 ºC, wherein the temperature at the inlet of the gap tube lies in the range from 500 to 750 ºC and in the outlet of the gap tube in the range from 650 through 850 ºC, a gas mixture containing steam and hydrogen is supplied through the gap tube at a load in the range from 0.01 to 0.4 kg H2/(m2 of catalytically active coating • h) (step b). |
