Kinetics of Thiophene Hydrodesulphurization: Pore Diffusional Effects

Abstract

Hydrodesulfurization (HDS) of straight‐run naphtha (SRN) reformer feed significantly improves reformer catalyst life, gasoline yield, and its stability. HDS of SRN helps in protecting the expensive platinum‐based reforming catalyst. HDS is usually catalyzed by sulphided Co–Mo/Al2O3 or sometimes Ni–Mo/Al2O3. The design of naphtha HDS units requires the development develop a kinetic model. It is well‐known that among the sulphur types present in naphtha, the most persistent sulphur compound is thiophene. Therefore, the design of naphtha HDS units is governed by thiophene HDS rates. It is essential to have experimental conditions free from intraparticle diffusional limitations in order to obtain intrinsic kinetics data. This Communication discusses the calculation procedures involved in ensuring experimental conditions free from pore diffusional resistances before conducting detailed kinetics studies. The pore diffusional resistance was quantified in terms of Thiele modulus (Φ).