Alkylation reactor pressure control
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Why is the pressure in the sulfuric acid alkylation reactor controlled by the sulfuric acid circulation rate? Seeking help from experts
I’m not entirely sure; sulfuric acid acts as a catalyst, and it seems that its purity needs to be around 95%, with continuous replacement of the sulfuric acid being necessary
The pressure in the reactor is controlled through feed and discharge; generally, it is regulated by the pressure at the top of the acid sedimentation tank
But here, is it the sulfuric acid circulation rate that controls the reactor pressure, or is it the pressure difference across the reactor filler?
In a vertical reactor, liquefied gas and acid flow downward through the bed; since sulfuric acid has a much higher viscosity than liquefied gas, it is the sulfuric acid that primarily maintains the pressure drop across the bed, with the pressure difference being controlled by sulfuric acid
Yes, but I still don’t understand why the amount of sulfuric acid controls the reactor pressure
Sulfuric acid is not used to control the pressure of the reactor; rather, it is used to control the pressure drop in the reactor, and it is through this pressure drop that heat release and absorption by the bed layer take place. The contact area of the reactor bed is designed in advance; that is, there is a specific range for the olefin space velocity. The bed pressure drop cannot be adjusted using liquefied gas. If attempts are made to adjust it via liquefied gas, it will affect the reaction rate and the pressure at the lower part of the reactor, and it is also necessary to increase the amount of circulating sulfuric acid in order to maintain the proper ratio of acid to hydrocarbons. Therefore, adjustment can only be carried out using sulfuric acid.
Is the heat release and absorption in the bed layer controlled by the amount of isobutane? I still don’t understand what you mean; could you explain it again?