Oxidation of NOX and SOX in Fossil Fuel Flue Gas by Atmospheric Oxygen with Nanocomposite Catalyst

Alon Khabra alonkh@gmail.com Tomer Zidki Haim Cohen
Department of Chemical Science, Ariel University, Ariel, Israel

Nitrogen oxides (NOx x=1,2) and sulphur oxides (SOx x=2,3) are the main air pollutants emitted in large scale from fossil fuels combustion. These gases are toxic and can cause many health and environmental problems. The environmental regulations limit the pollutants concentrations emitted to the atmosphere. Existing technologies used to decrease the pollutants concentrations are FGD (Flue-Das Desulfurization) and SCR (Selective Catalytic Reduction).1,2 However, these technologies use expensive catalysts and high working temperatures (350-400oC).

Some new wet scrubbing processes use ozone or hydrogen peroxide as oxidation reagents and produce fertilizers (ammonium sulfate and ammonium nitrate).

Here, we suggest a new heterogeneous nanocomposite catalyst of Co(OH)2 hydrolyzed on silica nanoparticles which can oxidize NOx and SOx using atmospheric oxygen. This catalyst (Co(OH)2)/Silica) has been used to oxidize water. 3

Using a wet scrubber concept, the catalyst dispersed in water slurry can oxidize SOx to SO4-2 and NOx to NO3- anions and upon ammonia (NH4OH) injection to the system, NH4NO3 and (NH4)2SO4 are produced in the catalyst solution. The decreasing of SOx and NOx emissions at 60˚C are >99% and 74%, respectively. The production of the nanocomposite catalyst and of the wet scrubbing process are discussed in detail.

References

  1. Busca, G., Lietti, L., Ramis, G., & Berti, F. (1998). Chemical and mechanistic aspects of the selective catalytic reduction of NOx by ammonia over oxide catalysts: A review. Applied Catalysis B: Environmental, 18(2), 1–36.
  2. Srivastava, R. K., & Jozewicz, W. (2001). Flue gas desulfurization: The state of the art. Journal of the Air and Waste Management Association, 51(12), 1676–1688.
  3. Zidki, T., Zhang, L., Shafirovich, V., & Lymar, S. V. (2012). Water oxidation catalyzed by cobalt(II) adsorbed on silica nanoparticles. Journal of the American Chemical Society, 134(35), 14275–14278.








Powered by Eventact EMS