Oxidation and absorption of nitric oxide in a packed tower with sodium hypochlorite aqueous solutions

The oxidation and absorption of nitric oxide (NO) with sodium hypochlorite aqueous (NaClO) solutions were studied to develop a two-stage chemical scrubbing system for NOx control. In the second stage, the most practical medium for NO2 absorption is sodium sulfite aqueous solution. Although a few two-stage systems have been installed, there are major gaps in developing NaClO aqueous solutions for NO oxidation in the first stage. Of particular importance is the lack of reliable information on rates of the chemical oxidation. A pilot-scale research program is initiated to evaluate the oxidation rate of NO with NaClO aqueous solutions in a packed tower. The research is directed toward obtaining the height of a transfer unit (HTU) for NO oxidation and acquiring reasonable operating conditions for the packed-bed scrubbing system. At pH 5.3, NaClO is an excellent scrubbing medium. The results are consistent with hypochlorous acid (HClO) being the oxidizing agent in the solution. The results also indicate that the liquid mass flow rate is a minor parameter that affects the NO oxidation and absorption in the scrubber. A NaClO concentration of >0.8% is crucial for high NO oxidation. © 2005 American Institute of Chemical Engineers Environ Prog, 2005

[1]  H. Shaw,et al.  Aqueous absorption of nitric oxide induced by sodium chlorite oxidation in the presence of sulfur dioxide , 1998 .

[2]  Towards ideal NO/sub x/ control technology using plasma-chemical hybrid process , 1999, Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370).

[3]  Masaaki Okubo,et al.  Towards ideal NO/sub x/ control technology using a plasma-chemical hybrid process , 2001 .

[4]  C. Cooper,et al.  Control of Nitrogen Oxide Emissions by Hydrogen Peroxide-Enhanced Gas-Phase Oxidation Of Nitric Oxide. , 1996, Journal of the Air & Waste Management Association.

[5]  Yusuf G. Adewuyi and,et al.  Aqueous Absorption and Oxidation of Nitric Oxide with Oxone for the Treatment of Tail Gases: Process Feasibility, Stoichiometry, Reaction Pathways, and Absorption Rate , 2003 .

[6]  T. Overcamp,et al.  Hydrogen Peroxide Scrubber for the Control of Nitrogen Oxides , 2002 .

[7]  E. Sasaoka,et al.  Simultaneous Removal of SOx and NOx Using Slaked Lime at Low Temperature , 2002 .

[8]  C. Yang,et al.  Oxidation of nitric oxide in a two-stage chemical scrubber using dc corona discharge. , 2000, Journal of hazardous materials.

[9]  C. Brogren,et al.  Absorption of NO in an Aqueous Solution of NaClO2 , 1998 .

[10]  Chen-Lu Yang,et al.  Absorption of NO2 in a packed tower with Na2SO3 aqueous solution , 2002 .

[11]  Y. A. Liu,et al.  Use of Simulation To Optimize NOx Abatement by Absorption and Selective Catalytic Reduction , 2001 .

[12]  S. M. Cho,et al.  Properly apply selective catalytic reduction for NOx removal , 1994 .

[13]  Chen-Lu Yang.  Aqueous absorption of nitrogen oxides induced by oxychlorine compounds : a process development study for flue gas treatment , 1993 .

[14]  H. Chu,et al.  Kinetic study on absorption of SO2 and NOX with acidic NaClO2 solutions using the spraying column , 2003 .

[15]  Moo Been Chang,et al.  Simultaneous Removal of Nitrogen Oxide/Nitrogen Dioxide/Sulfur Dioxide from Gas Streams by Combined Plasma Scrubbing Technology , 2004, Journal of the Air & Waste Management Association.

[16]  Jordan M. Haywood,et al.  The Economic Feasibility of Using Hydrogen Peroxide for the Enhanced Oxidation and Removal of Nitrogen Oxides from Coal-Fired Power Plant Flue Gases. , 1998, Journal of the Air & Waste Management Association.