Selective Catalytic Reduction How NOx Reduction Make the World Go Green

One of those toxins is called NOx. NO is nitric oxide and NO2 isnitrogen dioxide. Both of these are components of NOx in differentconcentrations. Typically, people have no idea that there is NOx aroundbecause not only is it colorless, it also has no odor. Because of this,it can unwittingly be released into the environment.

There are a plethora of places that have nitrogen oxide emissions.Almost half of all these emissions come directly from automobiles. Atthe turn of the century, a lot of people were driving around in large,gas guzzling SUVs that did nothing more than produce an increase inthese emissions. Ironically, the economic downturn has shaped thesociety into a more green-friendly nation. However, anything that usessome sort of a hydrocarbon for its gas will produce some form of NOx.Typically, most are found to be NO.

Often times, people question why this matters. They don't appreciatethe environmental concerns connected to NOx. The most important concernis the effect NOx has on the human respiratory system. NO combines withammonia which leads to the formation of nitric acid which is anincredibly strong acid that can do a serious amount of damage to thebody. Small particles get into the lungs and puncture holes in themwhich can lead to a potentially fatal result.

There are things that are being done to try and prevent this NOx frombecoming too much of an issue. In some areas, one of the big toolsbeing used is selective catalytic reduction. What this does innon-technical terms is create elemental nitrogen and water. Neither ofthese is harmful on the environment. In more technical terms, urea isused in the engine and then broken down into ammonia. The products ofthis reaction, after it has gone through a catalyst are those elementalnitrogen and water.

The SCR Catalyst has been shown to do a significant amount of work onthe NOx reduction. However, there are other routes, as well, that canbe used to try and reduce the NOx concentrations in the environment.One of these is the use of engine management which, as the namesuggests, is the control of the amount of emissions in an engine. Thereare fewer emissions released, but then the engine runs less effectivelywhich results in the build-up of soot.

One final method is a NOx trap which catches the NOx and thencatalytically converts that stored NOx, through acts of reduction, intobasic N2 and CO2. Nitrogen in its elemental form is not damaging to theenvironment. While CO2 can be damaging to the environment, it is notnearly as damaging as the NOx gases that are released by theautomobiles. CO2 is the lesser of two evils.

What these three techniques have in common is that they all are tryingto reduce the NOx levels. However, SCR catalyst is the one that hasbeen shown to have the most effect on the reduction of NOxconcentration levels. There is no concern of a lower effectiveness ofthe automobile and there is no need for a "lesser of two evils"approach because most of the NOx is converted into water and elementalnitrogen. The only downfall is that there needs to be some way ofgetting the urea into the system. If that occurs, this is definitely aneffective tool.

Each technique has its ups and downs. Some work better than others(SCR), but even that has its negatives. It is important to determinewhat the cost to productiveness ratio is that automobile companies arewilling to spend. What is too much? What is clear, though, is that theenvironment is not getting any stronger and if people are trulyconcerned about it, they need to take the necessary steps to preventagainst further degradation, if that means spending a little moremoney, that might be the necessary course of action.