Re: reducing nitrogen pollution?

Nitrogen is a byproduct of the combustion process!

I think the physicist C.E. White can correct me if I'm wrong?

Refinish King

I see where you're confused now. We're talking about two things that are related, but entirely different in regards to air pollution. Nitrogen, N2, makes up the vast majority of the air we breath. Oxygen, O2, is the next most plentiful gas, after which CO2 and AR and other trace elements fill out the mix. Nitrogen Oxides, NOx (a mix of NO3, NO4, etc) are pollutants that result from the combustion process. When the air*fuel mixture burns, the heat, if it gets excessive, can cause N2 to combine with O2, producing the various flavors of NOx. EGR is one way to reduce the heat, which is why it comes on many cars. N2 is relatively inert and has no effect on the environment, it's only when it's combined with O2 that it becomes poisonous.

JazzMan

Ref>

nitrogen is almost always inert as far as 'the combustion process' is concerned

before EGR, however, combustion chamber temps over a certain level (2100 degrees sticks in my mind, don't have the book here) would tend to fuse Nitrogen and Oxygen into oxides of nitrogen (gnerally rreferred to as 'NOx') which are the prime ingredient of smog

thus was born the EGR system, and the 'two-stage' catalytic converter; the first stage breaks down NOX's to N and O, the second stage uses the O to burn CO to CO2

Not really, nitrogen is just an innocent bystander. Combustion (strictly speaking) only involves gasoline and oxygen. But since air actually contains MORE nitrogen than oxygen (along with CO2, noble gasses, and a bunch of other trace elements) most of the air in the combustion chamber is made of nitrogen. When the gasoline and oxygen burn, the temperature shoots up high enough that a small portion of the nitrogen breaks down and recombines with oxygen to form nitrogen oxides, which are "smog precursor" chemicals. Lowering the peak combustion temperature a few hundred degrees goes a LONG way on preventing nitrogen oxide formation, which is why EGR is used. Introducing some exhaust gas slows the burn rate down and lowers peak temperatures.

A centrifuge couldn't separate oxygen from nitrogen. The molecular weights of O2 and N2 just aren't different enough. Impractical, even if you neglect all the added horsepower that would be required to spin the centrifuge....