Diesel Exhaust Pollutants

Basics

• This page lists the various directly harmful (ie not: nitrogen, oxygen, argon, co2) emmissions from diesel engines (and many other ice's)
• This is mainly as a lead in for Catalytic Converters , Diesel Particulate Filters, and Diesel Exaust Fluid systems
• Isn't too much of a small scale issue, but with a highway full of cars etc, it builds up
• IS FIXABLE, but there are many issues involving a Developer-User Disconnect Issues (may need better name) where it works on paper, but not i certain real life situations, or logistical issues of the supplies/maitnence needed, or hard to maintain systems etc

Emmissions

Nitrogen Oxides

• Nitrogen Oxides
• Often Abbreviated as NOx
• Caused by nitrogen and un-combusted oxygen being heated in the combustion chamber and reacting to form nitrogen dioxide, tridoxide etc\
• Main solution is Catalytic Converters, although others can be implemented depending on the predicted amounts produced (a sort of balancing act for the others)
  • The type of catalytic converter that does this "three way converter" doesn't work with high exhaust oxygen, as it would react with the catalysy

Soot

• Caused by incomplete combustion due to too little oxygen
• Mainly Carbon Black , but due to the impure nature of the fuel, and the combustion enviroment, it can often contain heavy metals, and other pollutants
• Balancing act here is lower oxygen in the ratio means less "pre-treatment system" NOx but more soot etc
• Thus either a perfect to lean fuel-oxygen ratio, or a Diesel Particulate Filter is needed
• For more in depth information on this, see Atmospheric Particulate Matter

Misc

• Other combustion products
• Various hydrocarbons

Solutions

Catlytic Converter

• Uses catalysts to convert Carbon Monoxide, or uncombusted hydrocarbons into water and carbon dioxide
  • This is reffered to as a "Two-way" converter, although 3 way is mandatory in most places, and thus should be easier to find?
  • May be cheaper due to less catalysts?
• More recent ones add the additional capability on NOx emmission conversion via the following reactions being catalysed

2 CO + 2 NO → 2 CO2 + N2 hydrocarbon + NO → CO2 + H2O + N2 2 H2 + 2 NO → 2 H2O + N2

• This may have higher cost, and also must alternate between lean and rich to have the right amount of oxygen for each reaction
• These also tend to not work well with diesel engines due to the exhaust oxygen percentage

DEF Based Scrubber

• Essentially a Gas Scrubber but scaled down to car etc sized
• Some SERIOUS logistical issues (no nearby places to buy the fluid, no "emergency" mode due to softwware locking etc)
• Some design issues (design allowing for easy accidental mixing, little storage, no way of knowing if the fluid is "not expired" ie all the amonia has evaporated off)
• If improperly managed can emit ammoonia gas (this is an issue of managment of the system however)
• Educational Issues (people don't know what it does, think it's a gimmick, using expired fluid etc)
• It is a workable solution, just needs better design (WITH user feedback), logistical fixes, and ease of use (that or use another system if this proves to be the more difficult option)

Exaust Gas Recirculation

• Does work, is commonplace, main issue is lower efficiency?

Internal Links

• Biodiesel
• Diesel Engines
• Diesel Exhaust Fluid

External Links

• The Wikipedia Page on Diesel Exhaust Pollutants
• On why three way converters are hard to use in diesel engines
• Moreso A Testament to the tech in said pickup truck, BUT "Leaf Blower's Emissions Dirtier than High-Performance Pick-Up Truck's, Says Edmunds' InsideLine . com"