Selective Catalytic Reduction For Flower Plants
Selective catalytic reduction is the process used to lessen NOx emissions hence controlling air pollution rates. The process involves the conversion of emissions into water and nitrogen gas. The process uses a catalyst in the form of ammonia or air, which is injected into the exhaust pipes hence holding the NOx gases. Once the gases have mixed thoroughly as the emissions pass through the catalytic bed NOx is reduced. The catalysts used are only meant to reduce the NOx but do not affect it. The by-product resulting from the reaction between urea and the emissions is carbon dioxide. Selective catalytic reduction usually reduces NOx emissions by 70 to 95%.
Power plants usually discharge huge volumes of the NOx gases as the power that is used is acquired from ignition of fuels. With this technique, these emissions have been reduced considerably. The process is made up of the reactor chamber, the catalyst bed, which holds the catalyst modules as well as an Ammonia injection grid system.
The moment the Ammonia steam gets fed into the exhaust pipes containing the emissions, it then passes all the way through the catalyts . This reduces the oxides of Oxygen as well as the toxic Nitrogen gas. This system makes use iof Urea, aqueous Ammonia together with anhydrous ammonia. Though all the catalysts used have their own disadvantages, urea is more popular. This technique has been accredited for its capability in reducing these toxic emissions at a great percentage.
Although the technique helps in elimination of a large percentage of harmful emissions, it has one major disadvantage. This is known as ammonia slips which releases unused ammonia from the system. This happens if proper maintenance of the necessary temperature is not carried out once the ammonia is injected into the reaction chamber. There have also been cases of ammonium sulfate and bisulphate emissions from these systems. This usually results from combinations of sulfates found in the air with excess ammonia. Sulfates have been linked to coughs and respiratory inflammations.
It has been proven that the correct use of these catalysts can be accredited for successfully removing 90% or more levels of these toxic gases. Various coal fired boilers in Virginia, which possess these catalyst systems, are capable of reducing the discharges by 60% to 65 %. On the other hand those fired by gas have managed to reduce more that 90%.
The system originated in the USA, founded by the Engelhard Corporation. It was yet to be tested by then. Later developments of the system were made in Japan and the US during the early 60s’. By then the research laid more focus on the agents of catalyzation that could be more durable and cheaper. The first system was then installed by the IHI Corporation in 1978.
The catalysts are produced from different ceramic materials that are used as carriers. These include Titanium Oxide. Usually, the active catalytic components are either oxides obtained from base metals like vanadium, zeolites or from precious metals. Catalysts obtained from base metals may be cheap, but they are not durable once subjected to high thermal. Zeolite catalysts are capable of withstanding higher temperatures. Plate type can withstand extreme temperatures, but they are quite expensive.
Best content writer in association with Cormetech Inc., the leading producer of titania-based ceramic honeycomb catalyst for NOx emissions control and NOx reduction used in Selective Catalytic Reduction (SCR) systems for air pollution control.
