| ign="center"> | | | | used in the engine and then broken down into |
| With the turn of the century, there has been an | | | | ammonia. The products of this reaction, after it |
| increase in concern over the health of the planet. | | | | has gone through a catalyst are those elemental |
| Scientist and the government work hard to try | | | | nitrogen and water. |
| and make changes to the environment. There | | | | The SCR Catalyst has been shown to do a |
| was a realization that without the world, there | | | | significant amount of work on the NOx reduction. |
| was no life and therefore, it was imperative to | | | | However, there are other routes, as well, that |
| save the world. With nations continuing to | | | | can be used to try and reduce the NOx |
| industrialize, it has become increasingly difficult to | | | | concentrations in the environment. One of these |
| curb the greenhouse gases and dangerous toxins | | | | is the use of engine management which, as the |
| that are destructive to the world. | | | | name suggests, is the control of the amount of |
| One of those toxins is called NOx. NO is nitric | | | | emissions in an engine. There are fewer emissions |
| oxide and NO2 is nitrogen dioxide. Both of these | | | | released, but then the engine runs less effectively |
| are components of NOx in different | | | | which results in the build-up of soot. |
| concentrations. Typically, people have no idea that | | | | One final method is a NOx trap which catches the |
| there is NOx around because not only is it | | | | NOx and then catalytically converts that stored |
| colorless, it also has no odor. Because of this, it | | | | NOx, through acts of reduction, into basic N2 and |
| can unwittingly be released into the environment. | | | | CO2. Nitrogen in its elemental form is not |
| There are a plethora of places that have nitrogen | | | | damaging to the environment. While CO2 can be |
| oxide emissions. Almost half of all these emissions | | | | damaging to the environment, it is not nearly as |
| come directly from automobiles. At the turn of | | | | damaging as the NOx gases that are released by |
| the century, a lot of people were driving around in | | | | the automobiles. CO2 is the lesser of two evils. |
| large, gas guzzling SUVs that did nothing more | | | | What these three techniques have in common is |
| than produce an increase in these emissions. | | | | that they all are trying to reduce the NOx levels. |
| Ironically, the economic downturn has shaped the | | | | However, SCR catalyst is the one that has been |
| society into a more green-friendly nation. | | | | shown to have the most effect on the reduction |
| However, anything that uses some sort of a | | | | of NOx concentration levels. There is no concern |
| hydrocarbon for its gas will produce some form | | | | of a lower effectiveness of the automobile and |
| of NOx. Typically, most are found to be NO. | | | | there is no need for a "lesser of two evils" |
| Often times, people question why this matters. | | | | approach because most of the NOx is converted |
| They don't appreciate the environmental concerns | | | | into water and elemental nitrogen. The only |
| connected to NOx. The most important concern | | | | downfall is that there needs to be some way of |
| is the effect NOx has on the human respiratory | | | | getting the urea into the system. If that occurs, |
| system. NO combines with ammonia which leads | | | | this is definitely an effective tool. |
| to the formation of nitric acid which is an | | | | Each technique has its ups and downs. Some |
| incredibly strong acid that can do a serious | | | | work better than others (SCR), but even that |
| amount of damage to the body. Small particles | | | | has its negatives. It is important to determine |
| get into the lungs and puncture holes in them | | | | what the cost to productiveness ratio is that |
| which can lead to a potentially fatal result. | | | | automobile companies are willing to spend. What is |
| There are things that are being done to try and | | | | too much? What is clear, though, is that the |
| prevent this NOx from becoming too much of an | | | | environment is not getting any stronger and if |
| issue. In some areas, one of the big tools being | | | | people are truly concerned about it, they need to |
| used is selective catalytic reduction. What this | | | | take the necessary steps to prevent against |
| does in non-technical terms is create elemental | | | | further degradation, if that means spending a little |
| nitrogen and water. Neither of these is harmful on | | | | more money, that might be the necessary course |
| the environment. In more technical terms, urea is | | | | of action. |