CATFLOW™ Success Story

Partager sur :

CATFLOW™ is a technology developed and patented by Petroval, for the unloading of a reactor catalyst bed via a horizontal dump pipe in the absence of a sloped dump nozzle (45°). The process uses an extraction tube that is inserted into the horizontal dump pipe. A fluidized region is created inside the extraction tube, and the catalyst is able to flow out by applying a delta P over the tube.

The top bed of reactor R01 had previously always been unloaded by vacuuming it out from the top. This year, in order to save time and catalyst, Spanish refinery decided to use the CATFLOW™ system during their July 2016 shutdown.


  • Increased safety by reducing inert entry.
  • Time saving by reducing the duration of the unloading phase.
  • Maximizing the amount of catalyst suitable for regeneration by avoiding breakage.

The unloading process using the CATFLOW™ method can be divided into 3 phases: gravity flow via CATFLOW™, easy dig-out via CATFLOW™, and final catalyst removal by vacuuming or dig-out (shoveling). The following table shows the pertinent information about the various phases:



  • No inert entry of personnel during catalyst free-flow unloading


  • Unloading rate: 10-12 m3 per hour
  • Transportable and fast installation on site


  • Quantity and quality of the recovered catalyst
  • Less attrition


2 beds (top bed unloading with CATFLOW™)
Internal diameter: 3,962 m
Catalyst volume: 88,82 m3
Catalyst unloaded with CATFLOW™: 64,99 m3


  • Safety: The exposure of technicians to nitrogen atmosphere was reduced by a factor of 4. For an unloading with vacuuming, inert entry into the vessel is required. To unload the whole bed by vacuuming would typically take about 30 hours. After the unloading with CATFLOW™, only 7½ hours of vacuuming was required to remove the remaining catalyst.
  • Time saving: The time needed to unload the top bed was reduced by 50%.
  • Catalyst recovery: Catalyst particles unloaded with CATFLOW™ does not suffer the breakage and attrition that is associated with catalyst unloaded by vacuuming. Thus, the amount of dust and fines is severely reduced, thereby leaving a larger amount of catalyst for regeneration (see here below photos).

news catflow 1

news catflow 2

This CATFLOW™ application was a great success. Inert entry time was reduced by 5%, the unloading duration was reduced by 50% and much more catalyst was recovered for regeneration.


The CARBODUMP® technology was not on site during this unloading operation. The association of this technology with CATFLOW™ could further reduce the vacuuming time and thus the duration of inert entry activities.