Deactivation of reforming catalyst

As time goes by, the activity of catalyst will gradually decrease, the selectivity will become worse, the aromatics yield and the octane number of generated oil will decrease. The main reasons for catalyst deactivation are as follows:

1）Catalyst carbon deposition. Because the carbon generated by the reaction covers the active component of the catalyst, the active component loses its function.

2）Condensation and fusion of active metals. Under the action of high temperature, the grains of the active metal components (mainly platinum) become large or dispersed unevenly, leading to the decrease of catalyst activity.

3）Poisoning. The feedstock contains sulfur, nitrogen, metal and other poisons. Although they are within the allowable target range, with the extension of operation time, the accumulation of poisons will lead to the contamination of the active components of the catalyst and poisoning.

4）Change of catalyst structure. At high temperature, the structure of catalyst itself changes, and the pore distribution deteriorates and the surface area decreases.

Except for metal poisoning and structural changes that permanently deactivate reforming catalysts, the first two types of deactivation can be restored or partially restored through the catalyst regeneration process.