Avoiding the Discharge of Dissolved Solids from a Wet Gas Scrubber

Most refiners remove SO2 from flue gas using wet scrubbing technology. This technology dissolves SO2 in water, creating a salt. These sulfur salts are eventually purged from the scrubber and then passed through the refinery wastewater treatment plant before being discharged with the final outfall. Although direct discharge of these salts is currently common in the United States, it is often not permissible in other countries where new wet scrubbers are currently being built. This paper summarizes current US practices, reviews alternate technologies to reduce the discharge of dissolved solids, and concludes with a case study of an innovative wet scrubbing system Norton Engineering Consultants has designed for a Chinese refiner.