Gas or Liquid Waste - High Levels of SOx or Cl₂/HCl

The quench section cools the flue gas to its saturation temperature by directly contacting it with water; the adiabatic absorbers remove inorganic acids and chlorine. Water is used in the first absorber to remove a majority of the HCl from the flue gas. The residual HCl and virtually all the entering Cl₂ leaves the absorber with the flue gas. A second absorber with caustic is used when either the Cl₂ or HCl in the flue gas exiting the first absorber exceeds allowable levels. This occurs when excessive Cl₂ is formed in the thermal oxidizer or when the first absorber is used to make acid.