Inhibition of Coke Formation in Heavy Oil Hydrotreating by Hydroaromatic Type Additives Derived from Petroleum

Coke formation in heavy oil treating has close relation with very many problems. It was found that the hydrocarbons which have high radical scavenging abilities can be obtained from petroleum through the studies to apply the pure hydrocarbon type radical scavengers to various purposes. Based on these facts, the tests to use this type of hydrocarbons were conducted for the purpose of the inhibition of coke formation in heavy oil hydrotreating. Kuwait and Arabian Heavy atmospheric residues were severely hydrotreated (desulf urization: 94%) with the pilot plant equipped with a downflow fixed bed reactor (catalyst: 400ml). By the addition of 3wt% of HHAP (hydroaromatic type additive derived from petroleum) to the feed, dry sludge formation was reduced to 1/5 and 1/16, respectively, and the stabilities by spot tests were also remakably improved.These results suggest that this type of additive could be a effective method to alleviate the many problems caused by coke formation in heavy oil hydrotreating.