| 摘要 |
The invention relates to a method for producing cracked gas containing ethylene by thermally cracking a hydrocarbon or hydrocarbon mixture in the presence of water vapor in a cracking tube at temperatures in the range of 600 to 1000 °C and at a cracked-gas outlet temperature in the range of 750 to 1000 °C, wherein the cracking tube comprises a steel in the region through which flow passes first, which steel is an alloy containing 25 – 35 wt% chromium, 25 – 55 wt% nickel, 2 – 6 wt% aluminum, and 10 – 30 wt% iron, whereby deposits containing carbon are avoided in the tube, and the cracking tube has a catalytically active coating on the inner surface in the region through which flow passes thereafter, which catalytically active coating avoids deposits containing carbon in the tube, wherein the cracking tube does not have the catalytically active coating on the inner surface in the region through which flow passes first. The invention further relates to a cracking tube for use in the method. |
