Catalytic oxidative desulfurization (ODS) is emerging as a potential alternative to deep hydroprocessing due to its milder operating conditions and no hydrogen requirements. In this study, ODS catalysts based on mesoporous TUD-1 support were developed to overcome the diffusion limitation of zeolite-based catalysts in oxidizing large-size organosulfur compounds present in real petroleum feedstocks. Different mesoporous oxidation catalysts were formed by substituting Ti in the TUD-1 framework and impregnating Keggin molybdenum heteropoly acid (HPA) on TUD-1 support. The mesoporosity of TUD-1, and the presence of Ti (IV) and Mo Keggin units in the prepared catalysts were confirmed from the characterization results of XRD, XPS, XANES, and BET-N2. The ODS performance of catalysts was studied using a mild hydrotreated bitumen derived heavy gas oil feedstock. The HPA dispersed Ti-TUD-1 catalyst was found to be most active for desulfurizing the heavy gas oil feedstock due to a strong synergy effect of Ti and Mo Keggin ions on catalyzing oxygen transfer from an oxidant to a substrate. Oxidants such as hydrogen peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, and molecular oxygen were screened in this study. The first two oxidants were better than others and equally efficient. The HPA /Ti-TUD-1 catalyst was found to be suitable for oxidative desulfurization and oxidative denitrogenation (ODN) both in the batch stirred tank reactor and continuous fixed-bed reactor systems.
|Original language||English (US)|
|Journal||Energy & Fuels|
|State||Published - Aug 20 2020|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The authors are thankful to King Abdullah University of Science and Technology (KAUST), Saudi Arabia for providing the financial support for this study through the center partnership funds, Canadian Light Source Inc for the XANES study and Ms. Rosa Do Phuong for assistance in analytical studies.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.