PROCESS FOR CONTROLLING THE PH VALUE OF AN ACID SCRUBBING LIQUID

摘要

The acid scrubbing liquid which has a pH value below 3 and is used in a scrubbing zone to remove acid components from a gas. At least part of the scrubbing liquid is circulated. A partial stream of the scrubbing liquid at a constant rate is mixed with an alkaline solution stream which has a constant concentration and is supplied at a constant volume rate, the pH value of the resulting mixture is continually measured, a setpoint in the range from 5 to 9 is selected for the pH value of the mixture, and a neutral or alkaline correcting liquid is added to the scrubbing liquid in response to a decrease of the measured pH value below said setpoint. The scrubbing liquid may mainly consist of water.