Regeneration

Regeneration is basically a controlled oxidation which eliminates coke and other combustible elements.

During the operating cycle the Hydroprocessing catalysts used in oil refineries and petrochemical plants get deactivated due to 3 major reasons such as coke deposit, sintering and metal contaminations. The first two can be eliminated by regeneration and the ex-situ method is becoming practise nowadays for a better performance recovery. The limits to regeneration often come from catalysts poisoning by various contaminants such as Vanadium, Arsenic or Silicon. This impact can be minimized by a careful management of the three actions "Sample, Analyze, Segregate"(SAS). This effort allows to maximize the quantity of catalyst recovery with the best possible quality assurance.

Regeneration consists in a controlled oxidation which eliminates coke and other combustible elements. Extensive analytical programs are needed in order to verify the properties of the spent catalysts and their suitability for reuse after regeneration. The industrial regeneration process most employed by Eurecat is based on the use of a Roto-louvre oven technology, which enables an excellent contact between gas and solids (Figure above). A high degree of homogeneity and excellent temperature control are achieved from the contact between hot air, passing through the spaces between the louvres and the thin layer of catalyst rotating slowly inside this conical inner shell. This process results in a very homogeneous and thorough regeneration while causing very little catalyst attrition and reducing catalyst breakage to a base minimum of <1%.

During the regeneration samples are taken at regular intervals and tested in the laboratory by specially trained operators ensuring proper quality control. The catalysts are sieved before and after the regeneration in order to eliminate the dust & fines and to ensure that regenerated catalyst will not induce any excessive pressure drop in the reactor.