Regeneration of the Industrially Deactivated Dehydrogenation Catalysts

Abstract

The loss of catalyst activity over time is a serious challenge in the industry and therefore performing the regeneration process is essential, especially for the catalysts that contain rare and expensive metals with adverse environmental impacts. This work focuses on the recovery of the Pt-based catalysts deactivated in the alkanes’ industrial dehydrogenation process. The Pt re-dispersion process on the catalyst surface was successful in the case of the regenerated catalyst. While fresh catalysts stayed intact when exposed to water during H₂ reduction, the regenerated catalysts were sensitive to hydrogen humidity throughout the reduction period. This could be related to the kinetic inhibiting effect of water molecules due to chlorine stripping. The design of experiments (DOE) technique was applied to statistically evaluate the factors that affect the activity of the regenerated catalysts. The optimum levels for the operating variables such as purity, flow rate, the humidity of hydrogen, as well as temperature and duration of the reduction were found to be 99%, 13 L/h, 20 ppm, 460 °C, and 4 h, respectively. These findings are very important as they are obtained based on realistic conditions, close to those applied in the industrial process. Consequently, this study offers new opportunities for the industrial dehydrogenation of long-chain alkanes from a practical, economic, and environmental point of view.