Alternative flue gas treatment technologies for integrated SO{sub 2} and NO{sub x} control

Enactment of the 1990 Clean Air Act Amendments, as well as passage of legislation at the state level has raised the prospect of more stringent nitrogen oxides (NO{sub x}) emission regulations and has fueled research and development efforts on a number technologies for the combined control of sulfur dioxide (SO{sub 2}) and NO{sub x}. The integrated removal of both SO{sub 2} and NO{sub x} in a single system can offer significant advantages over the use of several separate processes, including such factors as reduced system complexity, better operability, and lower costs. This paper reviews the status of a number of integrated flue gas cleanup systems that have reached a significant stage of development, focusing on post-combustion processes that have been tested or are ready for testing at the pilot scale or larger. A brief process description, a summary of the development status and performance achieved to date, pending commercialization issues, and process economics (when available) are given for each technology