Deactivation of hydrodemetallization catalyst by pore plugging

✍ Scribed by R. Galiasso; R. Blanco; C. Gonzalez; N. Quinteros

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 701 KB
• Volume: 62
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(83)90034-0

✦ Synopsis

The activity of hydrodemetallization catalysts was studied as a function of the time on stream. Three periods of deactivation were analysed, measuring the properties of the catalyst after each period. The activity in the first period decreased because of deposition of coke in the micro and meso pores, then vanadium deposition produced a progressive decrease in activity as a function of time. Vanadium being located in the mesa-macro pores. Finally, the catalyst was rapidly deactivated by coke and vanadium deposition in the exterior pores. The pores were plugged by large molecules using only the accessible mesa-macro structure. When the reaction was increased thermally and catalytically, the efficacy factor decreased. At the same time, multilayer deposition of vanadium in pore entrances reduced the effective diffusivity and the accessibility of large molecules to the interior of the particle. Both effects produced a heterogeneous distribution of metal through the particle.