Elimination of Coke in an Aged Hydrotreating Catalyst via a Non-Thermal Plasma Process: Comparison with a Coked Zeolite

Hawraa Srour (1) , Ammar Alnaboulsi (1) , Amir Astafan (1) , Elodie Devers (2) , Joumana Toufaily (3) , Tayssir Hamieh (3) , Ludovic Pinard (1) , Catherine Batiot-Dupeyrat (1)

1 IC2MP - Institut de Chimie des Milieux et Matériaux de Poitiers
2 IFPEN - IFP Energies nouvelles
3 MCEMA - Laboratoire de Matériaux, Catalyse, Environnement et Méthodes Analytiques

The removal of coke from an aged industrial hydrodesulfurization catalyst, using dielectric barrier discharge (DBD) non-thermal plasma with a pin to plate geometry, was investigated. The aged catalyst was introduced into the plasma reactor as a thin wafer. After 130 minutes of plasma treatment, with P = 30 W, 70% of the coke was removed while more than 40% of the sulfur was still present. Characterization of catalyst at different locations of the wafer showed that the coke was more easily removed at the center, close to the pin electrode where the electric field was more intense. The formation of an unexpected phase, under the plasma discharge, was highlighted, it corresponded to the family of Keggin HPA PMo12O403−, which could be an interesting precursor of catalyst for the hydrodesulfurization (HDS) process. Compared with a coked zeolite, the rate of regeneration is lower for the HDS catalyst under plasma discharge, while a lower temperature is required under conventional thermal oxidation. This is explained by the presence of metal particles, which could be responsible for the limitation in O-atom formation under plasma.

Keywords: non-thermal plasma; coked HDS catalyst; elimination of coke

Domains: Catalysis

Hawraa Srour, Ammar Alnaboulsi, Amir Astafan, Elodie Devers, Joumana Toufaily, et al.. Elimination of Coke in an Aged Hydrotreating Catalyst via a Non-Thermal Plasma Process: Comparison with a Coked Zeolite. Catalysts, 2019, 9 (9), pp.783. ⟨10.3390/catal9090783⟩. ⟨hal-02413177⟩