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I recently heard that passivation of Hydrotreating catalyst before shutdown will reduce the hazards by reducing the time of Inert entry in the reactors during shutdown. A process called Catnap passivation is used for the same. Can anyone brief whether it is useful and beneficial...?
08/07/2016 A: Saleh Daryabari, Senior Process Engineer of RCD and RFCC, Arak Refinery, daryabari@gmail.com
Some refineries apply passivation chemicals and unload catalysts into Big Bags. There are some problems applying liquid passivation; Catalyst is wet during unloading, which increased the unloading time; LEL is high at some points during the unloading; For reactors having maldistribution there are non-wetted catalysts which show pyrophoric behaviour; Also liquid might collect in the bottom of the Big Bags and leak to environment.
Taken the above into account it would be difficult to decide whether passivation chemical is beneficial or not.