Pump selection

The question is a bit too simple – what is the medium, is the vacuum level high or low, and what is the required head? If it is water, under the same system pressure, a regular centrifugal pump will suffice.

Hydrochloric acid absorption unit: Hydrogen chloride is generated in the production equipment and enters the falling film absorber under vacuum, where it is absorbed by water (dilute hydrochloric acid). It then flows into the hydrochloric acid storage tank. A circulation pump is connected to the outlet at the bottom of the tank, pumping the dilute hydrochloric acid from the tank back up into the falling film absorber, and this cycle repeats continuously to produce hydrochloric acid. My current conditions are: the vacuum level is greater than -0.097 MPa, approaching -0.099 MPa; the liquid level in the storage tank is about 1.5 m higher than the inlet of the circulation pump; and the height of the falling film absorber is approximately 10 m. The centrifugal pump I am using currently has a head of 30 m and a flow rate of 20 m3; it can function in low-vacuum conditions and is capable of pumping the liquid from the storage tank into the falling-film absorber. However, it cannot deliver the liquid to the falling-film absorber under high-vacuum conditions, which prevents the absorption of hydrogen chloride for acid production. Therefore, I would like to ask the experts: what type of pump should be used in a high-vacuum environment to transfer the liquid from the storage tank to the absorber above? Thank you!