(78d) Decoke Tutorial

When a cracking furnace reaches its end of run (EOR) condition, an online steam/air decoke will be conducted to gain back the performance of the radiant coils and primary quench exchangers. Decoke is a short-term operation and it has some unique features compared to normal cracking operation. During decoke, steam, air and heat are introduced into the system to burn off or carry away coke. Depending on the disposal method for the decoking effluent (decoke to firebox or to decoke drum), particulate matter (PM), NOx and CO emissions will be quite different. In this tutorial, procedures unique to the decoking operation and their impact on furnace equipment and components will be reviewed.