Reactive absorption of NO and SO₂ into aqueous NaClO in a counter‐current spray column

Abstract

The experiments were performed in a spray column to study the simultaneous absorption of NO and SO2 using NaClO solution from simulated gas stream under various experimental conditions. The effects of various influencing parameters, such as absorbent concentration, reaction temperature, initial SO2 and NO concentration, and initial pH of NaClO solution on simultaneous removal of SO2 and NO, were emphatically investigated in regard to coal‐fired thermal power plant stack gas emission control. The maximum removal efficiencies of SO2 and NO were found as 97% and 87.8%, respectively, at 313 K, initial NaClO solution pH 5.4 and 0.024 M NaClO concentration. The addition of CO2 in simulated gas stream was also carried out to see its influence on removal efficiency of SO2 and NO. The results using a spray column showed that NaClO can be used effectively for simultaneous removal of NO and SO2from coal‐fired thermal power plant simulated gas stream. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.

Removal and recovery of SO2 and NO in oxy-fuel combustion flue gas by calcium-based slurry

“…Thereupon, oxidizing insoluble NO to soluble NO 2 before wet scrubbing method is necessary. In this oxidizing process, many oxidation-absorption combined processes have been studied extensively to oxidize NO to NO 2 for the purpose of simultaneous removal of NO and SO 2 , including strong oxidizing agent injection [9], selective catalytic oxidation [10,11], and photo-catalytic oxidation [12].…”

Performance of a Monofiber Optical Probe in Determining the Droplet Size and Velocity in Spray Systems Compared with a High-Speed Camera

“…Gas absorption using spray columns is now a frequently applied process in various applications, including the removal of volatile organic compounds (VOCs), hydrogen sulfide (H 2 S), nitrogen oxide (NO X ) , sulfur dioxide (SO 2 ), and carbon dioxide (CO 2 ) from contaminated gases (Bashipour et al, 2015;Raghunath and Mondal, 2016;Tamhankar et al, 2015;Tatin et al, 2015). In spray systems, the hydrodynamics of droplets play an important role in controlling the absorption efficiency of the sprays because the droplet sizes and velocities directly affect the interfacial area available for absorption (Roustan, 2003).…”

“…Gas absorption using spray columns is now a frequently applied process in various applications, including the removal of volatile organic compounds (VOCs), hydrogen sulfide (H 2 S), nitrogen oxide (NO x ) , sulfur dioxide (SO 2 ), and carbon dioxide (CO 2 ) from contaminated gases. − In spray systems, the hydrodynamics of droplets play an important role in controlling the absorption efficiency of the sprays because the droplet sizes and velocities directly affect the interfacial area available for absorption . If a spray system is to be understood and utilized efficiently, then droplet size and velocity distributions need to be characterized. , Various studies have proposed their mechanisms of droplet formation, including droplet sizes and velocities, , and have been further used for simulation, optimization, and design of the processes. , So far, the optical techniques of phase-doppler anemometry (PDA), droplet tracking velocimetry (DTV), or high-speed cameras have been successfully used to determine droplet sizes and velocities. − However, most of the optical techniques encounter difficulties when used with dense spray or in conditions of poor visibility; only a few techniques showed promising results, for instance, optical flow estimation …”

Evaluation of FeIIEDTA‐NO reduction by thiourea dioxide in NO removal with FeIIEDTA

“…So far, SO 2 can be readily caught by wet process because of its higher solvability in solution. So adding oxidizing agents like KMnO 4, 5 NaClO 2, 6,7 NaClO, 8 and H 2 O 2, 9 for oxidizing NO into more soluble NO 2 and chelating agents 10,11 to unite NO, draws more interest, in which the removal of NO and SO 2 could be simultaneously finished off in a single process or equipment in wet process. For this reason, several approaches have been refined to improve NO absorption; one of which is selective catalytic reduction (SCR).…”

“…4 But it is difficult for SCR to achieve the purpose of desulfurization. So adding oxidizing agents like KMnO 4,5 NaClO 2,6,7 NaClO, 8 and H 2 O 2, 9 for oxidizing NO into more soluble NO 2 and chelating agents 10,11 to unite NO, draws more interest, in which the removal of NO and SO 2 could be simultaneously finished off in a single process or equipment in wet process. Fe II EDTA, an efficient absorbent of NO wet absorption from exhaust gas, is extensively investigated since 1970s by many research groups because of the fast complexing ability on NO.…”