Chemistry of a flue gas combined NOX and SO2 scrubber employing ferrous cysteine additives
✍ Scribed by Tu, M. D. ;Chang, S. G.
- Publisher
- American Institute of Chemical Engineers
- Year
- 1987
- Tongue
- English
- Weight
- 543 KB
- Volume
- 6
- Category
- Article
- ISSN
- 0278-4491
No coin nor oath required. For personal study only.
✦ Synopsis
Use of ferrous cysteine additives infEue gas scrubbing -systems creates a dqferent and simpler scrubber chemistry compared to Japanese processes using ferrous chelates such as Fe2+ (EDTA).
Instead of being concerted to nitrous oxide, nitric oxide in flue gus can be concentrated andlor reduced to nitrogen gas. Also, production of dithionate ions and nitrogen-sulfur compounds in scrubbing systems can be avoided. Fixation of nitric oxide occurs by a rapid reaction with the ferrous cysteine complex, at p H between 7.5 and 6.5, to form solid cystinatodinitrosyl iron (ZZ), which releases NO upon heating. Most of the NO is reduced to gaseous species, primarily N2, in ferrous cysteine solutions at pH 10. Cysteine can rapidly reduce ferric ion to ferrous ion while being oxidized to cystine. Cystine can be reduced back to cysteine by SO2.