大家要先搞清楚major species 和minor species 的區別

Major species follow simple calculation using mass balance; minor species do not. All smog-forming pollutants are minor species. For example, burning natural gas can be expressed globally as CH4 + 2O2 = 2H2O + CO2. So CO2 is a major species, and you cannot reduce emission of CO2 other than burning less NG.

But NO formation can be expressed globally as N2 + O2 = 2 NO. NO is a minor species created only by the right combination of conditions: high temperature, residence time etc. With the wrong conditions, you create a lot of them. With the right combustion technology, you creates very little.

The same is true for soot and CO. You can make 10,000 ppm of them, or close to none.

So don't say it is not possible to reduce them by 95%. Depending on where you start (how badly controlled the current burner is), you may be able to reduce it by 99.9%.