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  2. Selective catalytic reduction - Wikipedia

    en.wikipedia.org/wiki/Selective_catalytic_reduction

    Selective catalytic reduction (SCR) means converting nitrogen oxides, also referred to as NO x with the aid of a catalyst into diatomic nitrogen (N 2), and water (H 2 O). A reductant, typically anhydrous ammonia (NH 3), aqueous ammonia (NH 4 OH), or a urea (CO(NH 2) 2) solution, is added to a stream of flue or exhaust gas and is reacted onto a ...

  3. Selective non-catalytic reduction - Wikipedia

    en.wikipedia.org/wiki/Selective_non-catalytic...

    Selective non-catalytic reduction (SNCR) is a method to lessen nitrogen oxide emissions in conventional power plants that burn biomass, waste and coal.The process involves injecting either ammonia or urea into the firebox of the boiler at a location where the flue gas is between 1,400 and 2,000 °F (760 and 1,090 °C) to react with the nitrogen oxides formed in the combustion process.

  4. Diesel exhaust - Wikipedia

    en.wikipedia.org/wiki/Diesel_exhaust

    [not verified in body] While total nitrogen oxides from petrol cars have decreased by around 96% through the adoption of exhaust catalytic converters as of 2012, diesel cars still produce nitrogen oxides at a similar level to those bought 15 years earlier under real-world tests; hence, diesel cars emit around 20 times more nitrogen oxides than ...

  5. NOx adsorber - Wikipedia

    en.wikipedia.org/wiki/NOx_adsorber

    A NO x adsorber is designed to reduce oxides of nitrogen emitted in the exhaust gas of a lean burn internal combustion engine.Lean burn engines, particularly diesels, present a special challenge to emission control system designers because of the relatively high levels of O 2 (atmospheric oxygen) in the exhaust gas.

  6. Exhaust gas recirculation - Wikipedia

    en.wikipedia.org/wiki/Exhaust_gas_recirculation

    EGR valve the top of box on top of the inlet manifold of a Saab H engine in a 1987 Saab 90. In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide (NO x) emissions reduction technique used in petrol/gasoline, diesel engines and some hydrogen engines. [1]

  7. Nitrogen Oxide Protocol - Wikipedia

    en.wikipedia.org/wiki/Nitrogen_Oxide_Protocol

    Protocol to the 1979 Convention on Long-Range Transboundary Air Pollution Concerning the Control of Emissions of Nitrogen Oxides or Their Transboundary Fluxes, opened for signature on 31 October 1988 and entered into force on 14 February 1991, was to provide for the control or reduction of nitrogen oxides and their transboundary fluxes.

  8. Plasma cleaning - Wikipedia

    en.wikipedia.org/wiki/Plasma_cleaning

    Plasma cleaning is the removal of impurities and contaminants from surfaces through the use of an energetic plasma or dielectric barrier discharge (DBD) plasma created from gaseous species. Gases such as argon and oxygen, as well as mixtures such as air and hydrogen/nitrogen are used. The plasma is created by using high frequency voltages ...

  9. Nitriding - Wikipedia

    en.wikipedia.org/wiki/Nitriding

    In salt bath nitriding the nitrogen donating medium is a nitrogen-containing salt such as cyanide salt. [citation needed] The salts used also donate carbon to the workpiece surface making salt bath a nitrocarburizing process. [citation needed] The temperature used is typical of all nitrocarburizing processes: 550 to 570 °C.