Use of immobilized iron chelate catalysts for the combined removal of NO/sub x/ and SO/sub x/ from combustion flue gases. Final technical report, August 15, 1984-May 14, 1985

Technical Report · Wed Jul 31 00:00:00 EDT 1985

OSTI ID:5474506

Case, G D; Dalal, N S; Calmon, C; Gold, H

This report covers a laboratory-scale feasibility analysis on the use of immobilized iron chelate catalysts to simultaneously remove NO/sub x/ and SO/sub x/ from combustion flue gases. A large number of iron chelate wet absorption processes, mostly originating in Japan, have been implemented over the past 15 years, but were abandoned because of inefficient gas-liquid mass transfer, complex treatment and disposal of process by-products, and catalysts losses during blowdown or due to iron oxidation. The immobilization of iron chelates on a solid substrate would overcome many of the deficiencies encountered by the Japanese. Five metal chelate compounds were evaluated in aqueous phase tests and compared against an Fe-EDTA chelate, a catalyst used in some of the Japanese processes. The test chelates were selected to cover a wide range of bonding structures and oxidation-reduction characteristics relative to NO/sub x//SO/sub x/ removal. An iron phthalocyanine (FePc) catalyst was found to give enhanced NO mass transfer with a minimum of oxidation interference. The catalyst immobilization work focused on the absorption or binding of specified iron chelates to test substrates and the reactivity of each test material with nitrogen oxide and sulfur oxide derivatives. The most promising catalyst was FePc immobilized on a divinylbenzenechloromethyl polymer. This polymer is used as an intermediate in the synthesis of ion exchange resins. A loading of 4 percent by weight was achieved, which was stable against leaching in 0.1N acid media. Oxidation appears not to be a factor and its catalytic activity is adequate to support a process. The presence of dithionates, sulfates and nitrates in the by-products will greatly simplify by-product handling.

• Research Organization: Foster-Miller, Inc., Waltham, MA (USA)
• DOE Contract Number: AC22-84PC70266
• OSTI ID: 5474506
• Report Number(s): DOE/PC/70266-1; ON: DE85016122
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
20 FOSSIL-FUELED POWER PLANTS
54 ENVIRONMENTAL SCIENCES
DENITRIFICATION
CATALYSTS
DESULFURIZATION
FLUE GAS
IRON COMPLEXES
CATALYTIC EFFECTS
CHELATES
NITROGEN OXIDES
REMOVAL
SULFUR OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COMPLEXES
GASEOUS WASTES
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPLEXES
WASTES
010800* - Coal
Lignite
& Peat- Waste Management
200202 - Fossil-Fueled Power Plants- Waste Management- Noxious Gas & Particulate Emissions
500200 - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)