Coke in the Quench Oil loop causes many operational and maintenance problems. These problems include premature or unexpected plant shut downs, frequent heat exchanger, valve, and circulating pump maintenance, Quench Tower fouling as well as the health and environmental hazard while cleaning conventional standard and nonstandard filters.

The plant needed to improve its' run length and minimize maintenance. Removing the coke in the QO loop in an effective, safe and environmentally friendly method was the motivation for this project. The coke had to be removed without solvents and be clean, dry, and odor free when removed from the QO Loop.

The first reliable design to remove Coke from the QO was developed and implemented at Unipetrol RPA in 1997. There have been further improvements at other installations. The authors will discuss the operational and maintenance problems experienced before they started up the Coke Removal Unit and will also show how the Coke Removal Unit has improved the run length and almost eliminated maintenance on the heat exchangers and pumps.

Paper will be jointly written with Unipetrol in Litvinov Czech Republic, Slovnaft Petrochemicals in Slovak Republic, Facet Deutschland, and Intecha in Prague.