There are two avenues available to the refiner for the activity recovery of spent hydroprocessing catalysts

  1. a conventional thermal regeneration or
  2. a rejuvenation, also referred to as revitalization or reactivation.

Porocel announces new Excel® Rejuvenation Technology - MORE INFORMATION


The choice depends primarily on the type of catalyst and the desired amount of activity recovery.

A thermal regeneration involves the controlled application of heat to the spent catalyst. Sufficient heat is applied to remove volatile hydrocarbons, carbon and sulfur from the catalyst pores without thermally damaging the catalyst. Thermal regeneration is typically performed on older generation catalysts known as Type I, with recovered activity in the range of 70-85% of fresh activity, depending on the degree of metals contamination and surface area. Rejuvenation technology is not applied to Type I catalysts.

For more recent generation catalysts containing the highly active Type II sites, rejuvenation of the spent catalyst offers a means to restore greater than 90% of fresh catalyst activity, provided the spent catalyst meets certain physical and chemical criteria. In contrast, the application of conventional thermal regeneration to Type II catalysts results in only mediocre activity recovery.

There are several rejuvenation technologies available, depending on the catalyst manufacturer. In general, the rejuvenation process consists of two steps: an initial thermal regeneration to remove the carbon and sulfur, followed by a proprietary chemical treatment to redisperse the metals and restore/stabilize the Type II active sites for maximum activity recovery.

Criterion offers ENCORE revitalization on Centinel, Centinel Gold and Centera catalysts: Porocel provides the service under contract to Criterion.  Porocel is also approved by Haldor Topsoe for spent catalyst regeneration.



Porocel has independently developed Excel rejuvenation which restores the catalytic activity of a broad range of types of catalyst to greater than 90% of the catalyst's original activity for Type I and Type II catalysts.



As of November 3, 2020 Porocel is part of Evonik.
  • Evonik successfully completes acquisition of Porocel
  • All Porocel's products and services will be integrated into the Evonik Catalysts portfolio
  • Porocel sales channels will remain in place for the time being

Evonik is one of the world leaders in specialty chemicals. The company is active in more than 100 countries around the world. Evonik goes far beyond chemistry to create innovative, profitable and sustainable solutions for customers. More than 32,000 employees work together for a common purpose: We want to improve life today and tomorrow.