Pretreatments of Coils to Minimize Coke Formation in Ethylene Furnaces

Numerous techniques have been considered on how to reduce coke formation and/or coke collection on the inner surfaces of the coils in furnaces producing ethylene, propylene, etc. Such reduction would lead to several beneficial events including much reduced production costs. The techniques tested by Nova Chemical in several of their furnaces have resulted in a major reduction of coke. They have tested several pretreatments of the coils in their furnaces using several oxidizing gases at 800−1200 °C. For example, hydrogen/steam mixtures have been employed. Various pretreatments have been employed in the current study that suggest improved pretreatments are now possible.