Effect of catalyst and feed properties on the deactivation parameters of an ARDS process model for HDS and HDM reactions

Abstract

A mathematical model for the atmospheric residue desulfurization (ARDS) process was used to estimate the deactivation parameters for the hydrodesulfurization (HDS) and hydrodemetalation (HDM) reactions. These parameters, namely Thiele moduli and contact efficiency, were assessed for three commercial ARDS catalyst systems and three atmospheric residues. The model’s deactivation parameters were validated with the literature, even though the model’s structure did not explicitly model these free parameters mathematically. It was demonstrated that the Thiele modulus had a positive correlation with the pore volume of the fresh catalyst and a negative correlation with its bulk density for the HDS reaction. The lighter feed, in comparison to the other feeds, contacted the catalysts more efficiently under the current operating conditions. Metal removal depended on the catalyst pore structure, and vanadium removal seemed to be controlled by diffusion.

Keywords:

• Atmospheric residue
• catalyst system
• deactivation parameters
• hydrodesulfurization
• hydrodemetalation
• process modeling