Have anyone use platforming continuous catalyst circulation technology experience catalyst plugged in the bottom of Reforming reactor after turnaround? What may inhibit the catalyst flow to the regeneration section from bottom of reactor (catalyst collector)?
Peter Marsh, XBP Refining Consultants Ltd, email@example.com
You don't say whether this is a UOP or Axens type unit. I will assume UOP. Are you sure that the blockage is at the bottom of the stacked reactors? If so it could be a physical blockage such as construction debris blocking catalyst withdrawal funnels or it could be a problem with purge gas flow or temperature (too high a flow may cause catalyst hangup, too low a temperature may cause condensation of the reactor effluent stream making catalyst pills "sticky").
Have you considered that there could be a blockage within the Lift Engager (Atmospheric or Pressurised CCR) or L-Valve (Cyclemax CCR) or that primary and secondary lift gas flow meters may have been incorrectly calibrated? Have you considered that valve internals on Lift Engager inlet or outlet isolation valves may have separated from the valve stem such that the PLC logic thinks the valve is open when it is actually closed?