An Investigation of Coke Reduction on Stainless Steel 304 Alloy in the Steam Cracking of Heavy Naphtha Using Sulfide Inhibitors

The thermal cracking of hydrocarbons is one of the most important industrial processes producing olefin products including ethylene and propylene as desirable products. The undesirable process is coke formation, which causes several problems in thermal cracking reactors such as heat transfer reduction, increasing the pressure drop in the reactor, increasing fuel consumption, shortening the life of the reactor, and so on. Consequently, such undesirable affects can be decreased by choosing a proper alloy in reactor construction, using right feed, or some inhibitors. To prevent the formation of coke, some inhibitors were investigated. The variety of experiments showed that inhibitors like dimethyl disulfide and carbon disulfide could strongly decrease the coke formation. In this article, the reduction of coke formation and structural changes were investigated by using heavy naphtha as the normal feedstock entering the reactor, the above sulfide inhibitors, and stainless steel 304 as well as employing scanning electron microscope (SEM/EDAX) as an analysis technique.