Delayed coker
![A 4-drum delayed coking unit in a petroleum refinery](/Images/godic/202501/08/Delayed_Coker3100.jpg")
![A typical schematic flow diagram of a delayed coking unit](/Images/godic/202501/08/Delayed_Coker3100.png")
A delayed coker is a type of coker whose process consists of heating a residual oil feed to its thermal cracking temperature in a furnace with multiple parallel passes. This cracks the heavy, long chain hydrocarbon molecules of the residual oil into coker gas oil and petroleum coke.