Methods for replacing a spent catalyst of a reactor train of an operating hydroprocessing system

A method for replacing a catalyst of a reactor train of an operating hydroprocessing system, the operating hydroprocessing system comprising a plurality of reactor trains, each reactor train comprising at least one reactor comprising a catalyst and each reactor train configured to receive a feed fluid and combine a portion of the feed fluid with the catalyst to generate a hydrotreated fluid, the method comprising:

• (a) activating a valving system of the operating hydroprocessing system to disrupt operation of a select reactor train comprising a spent catalyst to form a disrupted reactor train while maintaining operation of at least one other reactor train of the plurality of reactor trains,
• wherein each of the plurality of reactor trains is fluidly connected to the valving system such that when activated the valving system can independently disrupt operation of each of the plurality of reactor trains,
• wherein each of the plurality of reactor trains is further connected to a gas processing system configured to remove a contaminant from the spent catalyst;
• (b) activating the gas processing system to remove the contaminant from the spent catalyst to form a decontaminated catalyst,
• (c) removing the decontaminated catalyst from the disrupted reactor train to form a catalyst free reactor train;
• (d) loading the catalyst free reactor train with a fresh catalyst to produce a charged reactor train;
• and
• (e) restoring operation of the charged reactor train.