NOx - offgasing

CO - Air 8 NOx offgasing Insensitive to radical source parameters but O3 formation is very sensitive to O3 offgasing rates. Formaldehyde data can also be used to derive formaldehyde offgasing rates. 

The NOx offgasing rates that fit the results of relevant experiments carried out in the first eight months of operation of this chamber are shown as the diamond symbols on Figure... 

Comparison of Radical Source and NOx Offgasing with Other Chambers... 

Figure 4. Plots of ratios of NOx offgasing or radical source to flie NO2 photolysis rates derived fi om modelling characterization rans for various chambers.

Therefore, the radical source and NOx offgasing rates indicated by the characterization data for the first series of experiments for this chamber is probably as low as one can obtain for reactors constructed of FEP Teflon film, which is generally believed to be the most inert material that is practical for use as chamber walls. Although die radical source and NOx offgasing rates for the second series of experiments is higher (see also Figure 3), they are still about an order of magnitude lower than observed for the UCR and UNC chambers previously used for mechanism evaluation. 

Evolved gases were monitored continuously for 02, C02, NOx, CO, and total hydrocarbons (THC) by a continuous emission monitoring system (CEMS). Batch samples of the offgases were also taken and analyzed for NH3, HCN, residual energetic materials, volatile organic compounds, and N2. The batch samples were collected over the entire duration of each run, and the single value reported represents the average concentration for the whole run. 

In order to avoid the unfavorable process conditions, different flue-gas treatment processes for combustion plants based on catalytic filters were developed, which combine fly-ash removal with SCR of ISKh with NH3 [4—8], The advantages of these processes are space and treatment-cost savings, reduced internal and external mass transfer resistances compared to honeycomb SCR catalysts, heat recovery from offgases with good efficiency, and low corrosion problems due to the removal of both dust and NOx at high temperatures. 

Where ki is the light intensity as measured by the NO2 photolysis rate, and RN is the NOx (and radieal) offgasing parameter, which is derived by model simulations of the appropriate characterization experiments to determine which value best fits the data. 

Figure 4. Plots of the mechanism under prediction bias for model simulations UCR EPA ambient surrogate - NOx experiments against normalized ROG/NOx ratios for the SAPRC-99 and Carbon Bond mechanisms. The SAPRC-99 calculations show effects of varying the MONO offgasing chamber effect parameters and using a lower OH + NO2 rate constant.

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