Mechanical treatment is carried out on catalysts to prepare them for their next cycle by selective removal of undesirable material.

1. Inerts and lumps removal

Due to gravity unloading, inert material is often mixed to the catalyst. In the EURECAT regeneration process, the catalyst/inert material mixture is screened through different sizes of sieves in order to remove the inerts, and sort them according to their diameter. Lumps which are resulting from catalyst particles agglomeration can also be sieved out from the catalyst during this process.
Broken material can be sorted out from the recovered inerts, with a specialized equipment.

2. Fines and dust removal

Catalyst fines are frequently the cause of pressure drop problems, and the off-site regeneration is often a good opportunity to carry out fines & dust removal.
Depending on the unit sensitivity to pressure drop, the size of the fines to be removed can be adjusted by mesh size selection.

Standard Sieving A communication with the process engineer in charge of the unit allows EURECAT to adapt the size of the sieves. Material quality is checked during the whole processing to give the customer the assurance the final product will present properties similar to the fresh catalyst.

Length Grading Sometimes, the unit pressure drop is not only due to the presence of fines in the catalyst load. It can be also due to the general shortening of the catalyst batch. In such a case, a single sieving would be insufficient to bring the catalyst batch back to the quality of the fresh corresponding batch. Particularly, it is sometimes necessary to remove also small particles that cannot be removed by the standard sieving. The EURECAT Length Grading technique is then the Solution to improve the particle size distribution significantly.

3. Density Grading

Density Grading is typically used when it is necessary to separate material with different densities.

This technique is mostly used to separate "heel" reforming catalyst in CCR units. During its operation, the CCR catalyst usually circulates in the reforming unit and undergoes a coking in the reaction section and then a decoking in the regeneration section, followed by an oxychlorination. However, there are specific zones in the unit reaction section where the catalyst cannot circulate, and remains immobile. The catalyst blocked in these zones is called heel catalyst and undergoes an important coking (up to 40 % of coke can be deposited on the catalyst). When the unit is cleaned up, there is a zone where the circulating catalyst is mixed up with the heel catalyst. Separation of both qualities of catalyst can only be carried out by Density Grading.