Catalyst regeneration system utilization for heat exchanger decoking

A method for decoking a heat exchanger, the method comprising:

• switching operation of a catalyst regeneration system from a catalyst regeneration operation to a decoking operation, wherein switching operation of the catalyst regeneration system from the catalyst regeneration operation to the decoking operation comprises:
• closing a first flow path of a regeneration gas of the catalyst regeneration system, wherein the regeneration gas comprises oxygen;
• diverting the regeneration gas from the first flow path to a second flow path coupled to the heat exchanger;
• and
• circulating the regeneration gas through the heat exchanger via the second flow path while the first flow path is closed to remove coke from the heat exchanger.

A system comprising:

• a catalyst regeneration loop comprising:
• a regeneration gas comprising nitrogen and oxygen;
• a burn zone configured to burn off coke from a catalyst using the regeneration gas;
• and
• an oxychlorination/calcination zone configured to chlorinate and dry the catalyst from the burn zone using the regeneration gas;
• a heat exchanger comprising an inlet and an outlet;
• a first flowline branching from the catalyst regeneration loop upstream of the burn zone and connecting to the inlet of the heat exchanger;
• a second flowline connecting the outlet of the heat exchanger to the catalyst regeneration loop downstream of the burn zone;
• and
• a flow subsystem comprising:
• a first flow element configured to control flow of the regeneration gas to the burn zone;
• a second flow element configured to control flow of the regeneration gas from the oxychlorination/calcination zone;
• a third flow element configured to control flow of the regeneration gas to the oxychlorination/calcination zone;
• and
• a fourth flow element configured to control flow of the regeneration gas through the heat exchanger via the first and second flowline, wherein:
• in a first operating mode:
• the flow subsystem is configured to divert flow of the regeneration gas from the catalyst regeneration loop to circulate through the heat exchanger by preventing, by the first flow element, flow of the regeneration gas to the burn zone, preventing, by the second flow element, flow of the regeneration gas from the oxychlorination/calcination zone, preventing, by the third flow element, flow of the regeneration gas to the oxychlorination/calcination zone, and allowing, by the fourth flow element, flow of the regeneration gas through the heat exchanger;
• and
• in a second operating mode:
• the flow subsystem is configured to circulate flow of the regeneration gas through the catalyst regeneration loop while prevent flow of the regeneration gas through the heat exchanger by allowing, by the first flow element, flow of the regeneration gas to the burn zone, allowing, by the second flow element, flow of the regeneration gas from the oxychlorination/calcination zone, allowing, by the third flow element, flow of the regeneration gas to the oxychlorination/calcination zone, and preventing, by the fourth flow element, flow of the regeneration gas through the heat exchanger.