Removal of Sulfur Dioxide From Stack Gases: Recent Developments in Lime-Limestone Wet Scrubbing Technology

Processes utilizing lime-limestone wet scrubbing technology are generally considered by the utility industry to be the best candidates for control of sulfur dioxide emissions from existing plants. Operating reliability is of prime concern and development work by several organizations is being conducted in an effort to find solutions to several major problems which are a deterrent to application of the processes. The problems include chemical scaling, process control, waste disposal, mist elimination, solids deposition in the scrubber circuit, and operation at reduced capacity. Results of experimental work in pilot and full-scale studies that bear on these problem areas are reported. Also, the status of plans for commercial application of lime-limestone wet scrubbing processes is summarized.