Reasons for the excessively high pH of the quench water

Since the pyrolysis gas contains acidic gases such as hydrogen sulfide, organic sulfur, and carbon dioxide, the quench water is generally acidic. Alkalis and ammonia are typically added to adjust the pH of the quench water in order to prevent corrosion of the equipment. However, when PH is greater than 9, quench water tends to emulsify easily. There are generally two types of emulsification issues: one is an excessive amount of alkali being injected, which can be caused by an inappropriate stroke length of the plunger pump or a high concentration of the new alkali; the other is the alkali from the cleaning system leaking to the front end. Even due to the separation tank at the alkali washing outlet, the interface meter became distorted, which caused the alkali solution to enter the quench water and led to an increase in the pH of the quench water!

Most of the aqueous waste liquids need to be returned to the quench tower; check whether the returned waste liquids have an excessively high pH value. Especially the condensate from the torch tank.