Regeneration of an aged hydrodesulfurization catalyst : Conventional thermal vs non-thermal plasma technology
Abstract
This study compares the regeneration efficiency of an aged industrial hydrodesulfurization catalyst (CoMoP/Al2O3) by conventional and alternative routes: thermal oxidation versus non-thermal plasma technology (NTP). Spent, partially, and fully regenerated catalysts have been characterized by XRD, XPS, and toluene hydrogenation to measure hydrogenating activity. Complete regeneration of the HDS catalyst via NTP requires the heating of the dielectric barrier discharge plasma reactor. Total removal of coke is obtained from 250 °C by applying only 8.6 W/gcatalyst, against 400 °C by conventional thermal treatment. The hydrogenation activity of the regenerated catalyst by NTP assisted by temperature is higher than that obtained by traditional thermal regeneration practiced industrially. Plasma treatment mitigates the oxide sintering but leads to the formation of cobalt oxide species preventing Co of fully playing its role as MoS2 slabs promoter. HDS catalyst regeneration using non-thermal plasma assisted by low temperature appears as a promising alternative to thermal combustion.