Abstract: The HDM activity stability and suitability of guard catalysts and main reaction catalysts for residues were tested in a pilot plant. The test device consists of fixed-beds with asymmetric switching guard reactors specially developed for residue hydrotreating process. The results showed that the layered main catalyst bed exhibits good activity stability and can run smoothly for 3 years in the case of feed in test. The developed residue hydrotreating system with asymmetric guard reactor shows a satisfied suitability for residue with different metal content, high impurities removal rate and good product distribution.

Key words: residue hydrotreating, guard reactor, operation cycle, fixed bed