Search results
Results From The WOW.Com Content Network
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 ...
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.
The sulfur is recovered as concentrated sulfuric acid and the nitrogen oxides are reduced to free nitrogen. The process is based on the well-known wet sulfuric acid process (WSA), a process for recovering sulfur from various process gasses in the form of commercial quality sulfuric acid (H 2 SO 4 ).
Selective catalytic reduction (SCR) injects a reductant such as ammonia or urea — the latter aqueous, where it is known as diesel exhaust fluid (DEF) — into the exhaust of a diesel engine to convert nitrogen oxides (NO x) into gaseous nitrogen and water.
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.
Within the SCR catalyst, the NO x are reduced by the ammonia into water and nitrogen, which are both nonpolluting. The water and nitrogen are then released into the atmosphere through the exhaust. [7] SCR was applied to automobiles by Nissan Diesel Corporation, and the first practical product "Nissan Diesel Quon" was introduced in 2004. With ...
From 2001 to 2005, Vectren installed four selective catalytic reduction (SCR) devices on all of the coal-fired units, which successfully cut nitrogen oxide (NO x) emissions by 80 percent. In 2004, Vectren replaced an existing electrostatic precipitator at Unit 1 with a fabric filter.
Emission rates for nitrogen oxides during the 2011 and 2012 ozone seasons reverted to essentially what they had been prior to SCR start up in 2003, resulting in the release of approximately 9,000 additional tons of NO x per season over what could have been achieved with full operation of this pollution control technology.