Ex-situ catalyst presulfiding

Porocel’s proprietary process of presulfiding is known as actiCAT pre-sulphurization process. Hydrotreating and hydrocracking catalysts are typically supplied with the active metals in the oxide form.

These metal oxides must be converted to metal sulfides (the active state of the catalyst) prior to use.

This is done in the process of catalyst sulfiding, when the catalyst is heated in the presence of hydrogen.

Technology description and benefits

Activity consideration

Since each catalyst pellet is treated with sulfur, actiCAT catalyst provides high levels of catalyst activity with minimal chance for metals reduction. In contrast, in-situ sulfiding requires excellent temperature control and flow distribution to avoid metals reduction and achieve full activity.

The activation of actiCAT presulfurized catalyst is fast and easy. There is no need for a dry-out step because the actiCAT catalyst is dried prior to processing, and its pores are filled with sulfiding chemicals, thus reducing its affinity for water. Once oil flow is established, the catalyst is simply heated to 315°C (600°F) in the presence of hydrogen to complete the activation. For a typical hydrotreater start-up, actiCAT saves about 18 hours compared with in-situ sulfiding. For hydrocrackers and very large hydrotreaters starts-up, the time savings can reach several days.

In addition to time savings, actiCAT presulfurized catalyst eliminates the handling of toxic, odorous sulfiding chemicals and the need for temporary pumping stations. In comparison with in-situ presulfiding the use of actiCAT catalyst is more convenient for the refiner in terms of health safety, environment and quality.

The use of dimethyl sulfide is excluded, due to that the risk of negative influence on the environment and staff (usually dealing with in-situ presulfiding) is also excluded.

Porocel’s actiCAT presulfiding is a unique, proprietary process in which sulfiding agent (sulfur) is tightly bound to the catalyst in an organic matrix. During the presulfiding process a range of sulfiding chemicals are generated. These chemicals react with hydrogen over a broad temperature range resulting in a gradual and controlled activation.

Time saving in comparison with in-situ sulfiding

The presence of sulfur in each catalyst granule and unique actiCAT technology, when the recovery of the metal oxide is impossible, can lead to an enormous saving of time compared with other methods sulfiding. All the necessary sulfur is already in the catalyst and there is no need to spend time spraying a sufficient amount of a sulfur-containing reagent or injecting sulfiding agent. Moreover, there is no need to make a break to check its proper distribution, which makes the activation process faster. Treatment period is limited only by the time during which the plant can be heated.

With actiCAT®ShieldSM refiner can work on cracked material immediately after heating without a 3-day break period.

Testing showed that the activity of catalysts treated with actiCAT®ShieldSM technology is equal or better than the activity of in-situ sulfided catalyst after a 3-day break period with 100% of straight-run gas oil (SRGO).

Technical services

In order to maximize the advantage of actiCAT, our company provides refiners with technical services, which includes:

  • general recommendations for storage, loading and handling the catalyst;
  • review of analytical reports (certificate of analysis) of the catalyst;
  • detailed examination of the start-up procedures specific for a unit;
  • possible participation in the start-up procedure if necessary.

The company offers five types of actiCAT presulfiding:

  • actiCAT®HT – for hydrotreating catalysts;
  • actiCAT®HC – for hydrocracking catalysts;
  • actiCAT®ShieldSM – to finish up the cracking feedstock up to required parameters (*);
  • actiCAT®PG – for Pygas catalysts (selective hydrogenation);
  • actiCAT®TG – for TailGas catalysts.

The company takes samples of the catalyst before and after the presulfiding, prepares the material balance, packing list, and certificate of analysis of actiCAT treated catalyst. The catalyst after actiCAT treatment shall be packed in sealed drums or containers. Presulfided catalyst is classified as a self-heating substance and must be transported in accordance with the 3190 UN.

The company provides MSDS and labels for marking of presulfided catalyst.

All the formalities related to packaging, transportation and customs clearance of the catalyst the company OptimLine Technologies shall settle on its own.

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