Development of combined nitrogen oxide/sulfur oxide environmental-control technology

Technical Report · Fri Aug 23 04:00:00 EDT 1985

OSTI ID:5257521

Harkness, J B.L.; Doctor, R D

Using a statistically designed series of batch experiments, we investigated simultaneous desulfurization and denitrification of flue gas from coal-fired boilers. Our results were consistent with mechanisms in which NO (nitrogen monoxide) and NO/sub 2/ (nitrogen dioxide) are coscrubbed as HNO/sub 2/ (nitrous acid), which reacts with SO/sub 2/ (sulfur dioxide) as (HSO/sub 3//sup -/) (the bisulfite ion) to form hydroxylamine-N-sulfonates. Significant pathways for aqueous-phase denitrification were available at pH values between 4 and 9, with an optimum at a pH value of 6.9. This report shows how these mechanisms operated in a variety of scrubber technologies, so that successful control strategies can be developed. Four desulfurization chemistries were ranked in terms of their denitrification potential, in the following order: double-alkali > lime > citrate > Dowa. A synthetic flue gas containing nitrogen blended with carbon dioxide (14.5%), oxygen (5.1%), SO/sub 2/ (1500 or 3000 ppM), NO (475 or 450 ppM), NO/sub 2/ (25 or 50 ppM), and water vapor (8%) was fed at 100 L/min (standard) to a 3.6-L batch sparger. Additives investigated included FeSO/sub 4/ (ferrous sulfate), Fe(II)EDTA, Cu(II)EDTA, Fe(II)NTA, Fe(OH)/sub 2/ (ferrous hydroxide), NH/sub 4/OH (ammonium hydroxide), and N/sub 2/H/sub 4/ (hydrazine), where EDTA signifies ethylenediaminetetraacetic acid and NTA signifies nitrilotriacetic acid. Of these additives, Fe(II)EDTA performed best as an enhancer of NO/sub x/ (nitrogen oxides) removal.

• Research Organization: Argonne National Lab., IL (USA)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5257521
• Report Number(s): ANL/ECT-14; ON: DE86001301
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200200 -- Fossil-Fueled Power Plants-- Waste Management
500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION CONTROL
AMINO ACIDS
AMMONIUM COMPOUNDS
CARBOXYLIC ACIDS
CHALCOGENIDES
CHELATING AGENTS
CHEMICAL REACTIONS
CONTROL
DENITRIFICATION
DESULFURIZATION
EDTA
FLUE GAS
GASEOUS WASTES
HYDRAZINE
HYDROGEN COMPOUNDS
HYDROXIDES
IRON COMPOUNDS
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POLLUTION CONTROL
SCRUBBING
SULFATES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
TRANSITION ELEMENT COMPOUNDS
WASTES