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The fluidized catalytic cracking catalysts are disabled for purposes of regeneration, pollutant load and the process of coking. The deactivation may be temporary or permanent depending on the cause of it.

Thermal deactivation occurs at high temperatures and is permanent, is usually caused by a reverse flow in the structure or an excessive use of torch oil. This loss of activity occurs by the fusion of active structures of the catalyst. This deactivation is more severe than the hydrothermal deactivation.

The analysis of thermally deactivated catalyst balance shows a significant presence of structures such as cristobalite and mullite, which are formed at temperatures above 1800 0 F.

Hydrothermal deactivation originates .- desaluminización of the zeolite and therefore cristanilidad loss and surface area, as well as changing the size of the pores. Desaluminización The mechanism is similar to that performed during manufacture of the catalyst, the difference is that there is no control over it. The vapor is always present in the catalytic cracking regenerator, representing about 15 to 25% V of the gas phase.

Deactivation by coking coke .- is responsible for providing the fuel or energy for the cracking process, but this causes the decrease of catalyst activity because of its deposition in the same as for his generation as a byproduct of the reactions cracking. However, this is a temporary loss of activity during the time when the load is in contact with the catalyst. After the coal is burned in the regenerator, the activity is recovered, unless otherwise occur at the same time off. This kind of deactivation can be decreased by limiting the contact time between the load and the catalyst.

Deactivation by Pollutant Load .- all crudes contain undesirable chemicals which are harmful to the process. Among the most damaging are:

Vanadium increases the hydrogen yield and delta coke. The dehydrogenation catalyst contributes to the formation of heavy olefinic compounds, which in turn form coke by reactions of condensation.

Nickel catalyst dehydrogenated about four times stronger than vanadium, yet does not cause loss of activity in it.

The alkali metals such as sodium form eutectics with fluidized catalytic cracking, these eutectics may melt causing the loss of activity and in extreme cases the collapse of structure.