Core activities


Hydrotreating catalysts are active once in a sulfided form. Until recently, fresh or regenerated catalysts were delivered to the end users in oxide form, and the sulfiding step was performed once the catalysts had been loaded into the reactor (in-situ). Various sulfiding agents could be used: feedstock, H2S, spiking agents such as DMDS. Ex-situ sulfiding avoids many potential problems that in-situ sulfiding creates (smell, malfunctioning DMDS injection pumps, dosage problems). Apart from it being safer and easier, ex-situ sulfiding is also better than in-situ sulfiding. The sulfur level on the catalyst is analysed continuously during the process, so there is no underdosing and no overdosing. Our sulfiding facilities have been designed such that the sulfur is distributed very uniformly, such that the sulfur distribution problems that you can have in-situ are avoided.


Last but not least, ex-situ sulfiding is a considerable time gain, especially in the case of the new TOTSUCAT, process offers a ready-to-use activated catalyst. As catalyst already contains the metal sulfided phase, the start-up procedure now only requires the heating up of the unit to start-of-run conditions.

In other words: the startup is done as if no catalyst changeout had occurred.

Catalyst once passivated

  • Is non-pyrophoric
  • Is self-heating catalyst
  • Is classified as UN 3190
  • Can be transported in UN-Y approved metallic drums or containers.

Both fresh and regenerated catalysts are TOTSUCAT'ed by us on a routine basis.

There are different TOTSUCAT varieties for different types of units and catalysts. We will provide you with more specific information on request.


Eco-Rigen is able to carry out different kinds of customised sulfiding (preconditioning) processes, which can be specific for each catalyst.