Combined NO sub x /SO sub 2 removal in spray-dryer FGD systems

Conference · Tue Jan 01 04:00:00 EST 1991

OSTI ID:6146414

Livengood, C D

A combination of modified process conditions and addition of caustic soda to a lime-based spray-dryer system was evaluated for its value in promoting combined NO{sub x}/SO{sub 2} removal from flue gas resulting from the combustion of high-sulfur coal. Small-scale tests at the Pittsburgh Energy Technology Center identified key process parameters. Subsequently, two test series, each about one month in duration, were carried out at Argonne National Laboratory in 1986 and 1988 using a commerical-scale (20 MW electric equivalent) spray-dryer/fabric-filter system. Sprayer-dryer outlet temperature was identified as a key factor, with NO{sub x} removal becoming significant above about 180 F and gradually increasing up to the maximum temperature investigated (210 F). No upper limit on removal with increasing temperature was observed. Removal of NO{sub x} was strongly proportional to baghouse filter-cake thickness; nearly all NO{sub x} removal occurred in the baghouse, with a small net production of NO{sub 2}(<15 ppm). The NO{sub x} removal was also proportional to the SO{sub 2}/NO{sub x} ratio, with little NO{sub x} observed at SO{sub 2}/NO{sub x} ratios less than 2:1. Caustic soda addition improved NO{sub x} removal, at least partially through creation of a more porous and reactive filter cake. Steady-state removals of 70% for SO{sub 2} and 35% for NO{sub x} were easily attained. 10 refs., 9 figs., 3 tabs.

• Research Organization: Argonne National Lab., IL (USA)
• Sponsoring Organization: DOE; USDOE, Washington, DC (USA)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6146414
• Report Number(s): ANL/CP-72548; CONF-910331--1; ON: DE91008835
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010800 -- Coal
Lignite
&amp; Peat-- Waste Management
20 FOSSIL-FUELED POWER PLANTS
200202* -- Fossil-Fueled Power Plants-- Waste Management-- Noxious Gas &amp; Particulate Emissions
ADDITIVES
AIR POLLUTION CONTROL
ALKALI METAL COMPOUNDS
BAGHOUSES
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
COAL
COMBINED SOXNOX PROCESSES
CONTROL
DENITRIFICATION
DESULFURIZATION
DRYING
ENERGY SOURCES
EQUIPMENT
FILTRATION
FLUE GAS
FOSSIL FUELS
FUELS
GASEOUS WASTES
HOT GAS CLEANUP
HYDROGEN COMPOUNDS
HYDROXIDES
MATERIALS
OXYGEN COMPOUNDS
POLLUTION CONTROL
POLLUTION CONTROL EQUIPMENT
PURIFICATION
SEPARATION PROCESSES
SODIUM COMPOUNDS
SODIUM HYDROXIDES
SPRAY DRYING
TEMPERATURE EFFECTS
WASTES