catalyst regeneration

In the process of using catalytic hydrogenation catalyst, its activity will gradually decrease until it cannot meet the process requirements or it is economically unreasonable to continue to operate, which is called deactivation. The deactivation rate of catalyst is related to the nature of raw materials, operating conditions and the quality of catalyst. For hydrogenation catalyst, its total life is generally 3~5 years. If the raw oil is light, less impurities and reasonable use, the total life of catalyst can reach 7~8 years, or even longer.

Catalyst deactivation is classified into two categories, renewable temporary deactivation and non-renewable permanent deactivation. The main cause of temporary deactivation of hydrogenation catalyst is carbon accumulation or coking. In the hydrogenation process, the olefins, diolefins, thick cyclic aromatic hydrocarbons, colloids, asphaltenes and sulfur, nitrogen and oxygen compounds in the raw oil are prone to polymerization, condensation and other side reactions to form carbon deposits, and gradually deposited on the catalyst, covering the active center of the catalyst, resulting in inactivation. Generally, when the carbon accumulation on the hydrogenation catalyst reaches 10%~15%, it needs to be regenerated. The deposition of metal elements on the catalyst causes the permanent deactivation of the catalyst.

The regeneration of hydrogenation catalyst is to burn the carbon on the catalyst with oxygenated gas and burn it off from the catalyst. Due to the carbon combustion, will release a lot of heat, at the same time, hydrogenation catalyst is used in the vulcanization state, metal sulfide in the regeneration, will also burn, release heat. Therefore, taking away the heat generated by regeneration in time and controlling the regeneration temperature is the key to affect the regeneration effect.