The role of the nitrogen seal tank in UOP catalyst regeneration
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The deactivated catalyst is displaced from the bottom of the fourth reactor by hydrogen to remove the hydrocarbons it contains, then lifted by nitrogen to the separation hopper; there, the powder in the catalyst is blown off before it enters the regenerator. After reacting in the regenerator, the raw catalyst is sent to the lockhopper via a nitrogen-sealed tank. . . I would like to ask, in this process, what other functions does the nitrogen-sealed tank have besides serving as a buffer? I saw in another post that it mentioned the oxygen and hydrogen environments during catalyst regeneration in isolation. Here, the catalyst first passes through the regenerator and then goes to the nitrogen-sealed tank.
Regenerator---------------oxygen environment; Closed hopper-------------hydrogen environment. The nitrogen-sealing tank is located in between, creating nitrogen bubbles to isolate hydrogen from oxygen
The regenerator is in an oxygen-rich environment, while the sealed hopper is in a hydrogen-rich environment; nitrogen helps to separate the gases from these two different environments, thereby preventing dangerous situations such as explosions Considered from a safety perspective!
The pressure in the nitrogen-sealed tank is higher than that in both the regenerator and the lockhopper, serving to isolate it from both oxygen-rich and hydrogen-rich environments.
The regenerator is in an oxygen environment, while the lockhopper is in a hydrogen environment; the combination of these two gases can cause an explosion. Therefore, a nitrogen seal tank is needed to separate the two gases, with its pressure being slightly higher than that of the regenerator and the lockhopper.
Nitrogen seal tube pressure – Regenerator pressure = 5 KPa. Nitrogen seal tube pressure – Lockhopper pressure = 5 KPa. In short, a certain amount of nitrogen should flow upward and downward to prevent hydrogen and oxygen from mixing with each other
The simplest concept of a nitrogen bubble is to maintain a region filled with pure N2 gas between hydrogen-containing equipment and oxygen-containing equipment, thereby separating hydrogen/hydrocarbons from oxygen using the \"nitrogen bubble\". The distribution of process media in the CYCLEMAX reaction regeneration system is shown in Figure 55; hydrogen/hydrocarbons and oxygen are separated using \"nitrogen bubbles\". To achieve this, the pressure in the pure N2 area must be higher than the pressure of the equipment on both sides. The nitrogen bubbles in the reaction section are maintained just below the reactor, that is, in the feed catalyst delivery system and the separation hopper ； The nitrogen bubbles in the regeneration system are just below the regenerator, that is, the nitrogen seal tank. The pressure difference between the reactor and the regenerator is created by the pressure gradient present throughout the catalyst riser. The airflow moves from high pressure to low pressure, with the resistance of the catalyst bed maintaining the pressure drop. This pressure gradient must be maintained between the separation hopper and the regenerator, as well as between different sections within the lumpy material hopper. The more obvious \"nitrogen bubbles\" are: the nitrogen seal tank, the raw catalyst lifting system, and the separation hopper.
1. Nitrogen addition point 2. Catalyst replacement during operation