Combined SO sub 2 /NO sub x control using ferrouster dot EDTA and a secondary additive in a lime-based aqueous scrubber system. [Sodium ascorbate]

• Main Authors: Mendelsohn, M.H., Livengood, C.D., Harkness, J.B.L.
• Language: unknown
• Published: 2008
• Subjects: 01 COAL; LIGNITE; AND PEAT; 20 FOSSIL-FUELED POWER PLANTS; 54 ENVIRONMENTAL SCIENCES; ANTIOXIDANTS; FLUE GAS; DESULFURIZATION; NITROGEN OXIDES; AIR POLLUTION CONTROL; SULFUR DIOXIDE; ADDITIVES; CALCIUM HYDROXIDES; COMBINED SOXNOX PROCESSES; EDTA; IRON; PYROGALLOL; SCRUBBERS; SODIUM CARBONATES; UREA; ALKALI METAL COMPOUNDS; ALKALINE EARTH METAL COMPOUNDS; AMIDES; AMINO ACIDS; AROMATICS; CALCIUM COMPOUNDS; CARBON COMPOUNDS; CARBONATES; CARBONIC ACID DERIVATIVES; CARBOXYLIC ACIDS; CHALCOGENIDES; CHELATING AGENTS; CHEMICAL REACTIONS; CONTROL; DEVELOPERS; ELEMENTS; EQUIPMENT; GASEOUS WASTES; HYDROGEN COMPOUNDS; HYDROXIDES; HYDROXY COMPOUNDS; METALS; NITROGEN COMPOUNDS; ORGANIC ACIDS; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; OXIDES; OXYGEN COMPOUNDS; PHENOLS; POLLUTION CONTROL; Carbonic acid
• Online Access: http://www.osti.gov/servlets/purl/6025595; https://www.osti.gov/biblio/6025595

Integration of NO{sub x} control into existing flue-gas desulfurization (FGD) systems addresses site-specific control requirements while minimizing retrofit difficulties. Argonne has studied the use of the metal-chelate additives, such as ferrous{center dot}EDTA in various wet FGD chemistries, to promote combined SO{sub 2}/NO{sub x} scrubbing. A major process problem is oxidation of the iron to the ferric species, leading to a significant decrease in NO{sub x}-removal capability. Argonne discovered a class of organic compounds that, when used with ferrous{center dot}EDTA in a sodium carbonate chemistry, could maintain high levels of NO{sub x} removal. However, those antioxidant/reducing agents are not effective in a lime-based chemistry, and a broader investigation of antioxidants was initiated. This paper discusses results of that investigation, which found a practical antioxidant/reducing agent capable of maintaining NO{sub x} removals of about 50% (compared with about 15% without the agent) in a lime-based FGD chemistry with FE(II){center dot}EDTA. 5 refs., 10 figs.