Nitrogen oxides removal by pulsed corona enhanced wet electrostatics precipitation

Conference · Thu Jul 01 04:00:00 EDT 1999

OSTI ID:20002210

Tseng, C H; Keener, T C; Khang, S J

This paper presents the results of a bench-scale pulsed-corona enhanced wet electrostatic precipitator (wESP) application for removal of nitrogen oxides. This wESP is designed to operate wet/dry, positive/negative, and pulsed/non-pulsed conditions. The applied pulsed voltage is varied from 0 to 60 kV at 70 Hz. Gas flow rate is a nominal 7 m{sup 3}/hr and the collecting electrode area is 0.20 m{sup 2}. A simulated flue gas with NO concentration up to 1,200 ppm{sub v} has been used to determine the feasibility of NO{sub x} removal in the wESP. NO has to be oxidized to N{sub 2} before any removal takes place. NO{sub x} removal efficiency increased with gas residence time, inlet NO concentration and applied corona power. In the air stream with 10 seconds gas residence time, up to 20% of 1,000 ppm NO (or 22% NO{sub x}) was removed from an air stream of 1.9x10{sup {minus}3} m{sup 3}/s with a water flow of 6.3 x 10{sup {minus}5} m{sup 3}/sec and 20 W, 70 Hz pulsed corona. Both ammonia and ozone injections improve the NO{sub x} removal for both the corona and non-corona cases. With the inclusion of NH{sub 3} (NH{sub 3}/NO{sub x} ratio 1.3) and 25 watts corona power, NO removal efficiency was increased from 28% to 57%. The amount of in-situ ozone is not enough to be considered as a major NO{sub x} removal mechanism in this wESP. However, the additional injection of ozone improves the NO removal from 29% to 38% for both the corona and non-corona cases. When the oxygen concentration is dropped to 3% in a simulated flue gas with 12% CO{sub 2} and 800 ppm NO and 70% relative humidity at 11.5 s of gas residence time, the removal efficiency of NO is only 5%. Adding NH{sub 3} (NH{sub 3}/NO{sub x} ratio 1) at 76 watts corona power, NO removal is increased to 13%.

• Research Organization: Univ. of Cincinnati, OH (US)
• OSTI ID: 20002210
• Report Number(s): CONF-990608--
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
AIR POLLUTION ABATEMENT
DESIGN
ELECTROSTATIC PRECIPITATORS
FLUE GAS
INDUSTRIAL WASTES
NITROGEN OXIDES
PERFORMANCE
WASTE PROCESSING