Simultaneous Removal of SO2 and NOx From Flue Gas

LIAN+Xu　WANG+Shu-bo　GUO+Yuan-feng　LIANG+Xiao

【Abstract】In this paper，the recent progress of simultaneous removal of SO2 and NOx process at home and abroad is reviewed.We mainly introduced calcium based absorbent catalytic oxidation method，complexation absorption process，Electron beam method et al，principle of each technology are described，and the development direction was put forward in the future.

【Key words】SO2；NOx；Simultaneous removal of SO2 and NOx

SO2 and NOx is the main cause of acid rain， so simultaneous removal of SO2 and NOx from flue gas is inevitable trend in the control of atmospheric pollution[1].

1 Simultaneous removal of SO2 and NOx using calcium absorbent

The most mature，stable operation and widely used of the desulfurization process is limestone-gypsum method. Replacing limestone with slaked lime as the main absorbent can remove SO2 and NOx[2]. 2 Complexation absorption method

Sada[3] and Chang[4] et al have found that some metal complex（Fe（EDTA）and Fe（NTA））can react with dissolved NOx quickly and form ferrous nitrosyl chelate，thus promotes the dissolved of NO in water. 3 Electron beam method

The principle is using high energy electron beam irradiation on flue gas，generated a lot of active material，the flue gas of SO2 and NOx oxidated into SO3 and NO2，further generate H2SO4 and NaNO3， and absorbed by NH3 or CaCO3[5-7]..

4 Expectation

At present，the desulfurization technology at home and abroad has been mature，but the denitration technology is still in the study and preliminary stage.From the future development trend，a lot of waste water and residue produced by wet method can cause secondary pollution. Considering the process and simple operation and recovery of sulfur resources，dry process desulphurization is the direction of future development.So we should step up research of dry desulfurization denitration technology，including the development of more efficient adsorption/catalyst.

【References】

[1]WANG R.The Research of Simultaneous Desulfurization and Denitration and Industrial Application[J].Applied Energy Technology，2013（3）：14-16.

[2]ZHANG H，TONG H L，WANG J Y，et al.Simultaneous Removal of SO2 and NO by Using Calcium Absorbent with KMnO4 as Additive[J].Journal of Chemical Industry and Engineering， 2007，58（7）：1810-1815.

[3]Sada E，Kumazawa H，Kudo I，et al.Individual and Simultaneous Absorption of Dilute NO and SO2 in Aqueous Slurries of MgSO4 with Fe2+-EDTA[J].Ind.Eng. Chem.Proc.Des.Dev，1980，19：377-382.

[4]Chang S G，Littlejohn D，Lynn S.Effects of Metal Chelates on Wet Flue Gas Scrubbing Chemistry[J].Environ.Sci.Technol，1983，17：649-655.

[5]WANG X H， FANG X C.Progress in Simultaneous Removal of SO2 and NOx From Flue Gas[J].Contemporary Chemical Industry，2008，37（2）：197-200.

[6]Ighigeanu D，Martin D，Zissulescu E，et al.SO2 and NOx removal by electron beam and electrical discharge induced non-thermal plasmas[J].VACUUM，2005，77：493-500.

[7]Ahmed A.Osama I.Noushad.K，et al.Electron beam flue gas treatment（EBFGT） technology for simultaneous removal of SO2 and NOx from combustion of liquid fuels[J]. Fuel.2008，87：1446-1452.

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