Quote:

Catalytic converters have nothing to do with it. H2O is a natural byproduct of burning any hydrocarbon (e.g. gasoline).



A small amount of water is the byproduct of combustion, the majority of which comes from water vapor already in the air used in combustion process. However the vast majority does come from the catalytic conversion process!

A catalytic convertor removes the pollutant gases from the exhaust by reducing or oxidising them. Precious metals are used as catalysts in the process, like an alloy of platinum and rhodium (35% and 73% respectively in US). Palladium metal may also be the choice.

Reactions (heterogenous catalysis) take place in the convertor. Both NOx and CO are eliminated together by a redox reaction on rhodium catalyst. NOx oxidises CO to CO2, and is reduced to harmless nitrogen gas (N2).
2NO(g)+ 2CO(g) pasing over rhodium= N2(g)+2CO2(g) (reduction and oxidation process)


CO and CxHy are oxidised by air on platinum catalyst. (C7H16 is used to represent the unburnt hydrocarbon)
2CO(g)+O2(g)passing over platinum= 2CO2(g) (oxidation process)
C7H16(g)+11O2(g) passing over platinum= 7CO2(g)+8H2O(g) (also oxidation process)

For all these reactions to happen, the convertor is designed as a 'three-way convertor' and has an oxygen monitor fitted to the engine. The monitor checks the quantity of oxygen into the engine to make sure there is enough oxygen in carrying out oxidation reactions.

The overall result of passing exhaust gases through the catalytic chamber is to convert the harmful CO, NOx and CxHy to relatively harmless N2, CO2 and H2O . Though the exhaust gases are in contact with the catalyst for only 100 to 400 ms, 96% of hydrocarbons and CO are converted to CO2 and H2O . The emission of nitrogen oxides is reduced by 76%.


Quote:

Drug store rubbing alcohol will not work because it's been saturated with water.



No, it is not saturated with water at that point. To prove it, put some in a glass and add water!








Former, now returned CEG'er! 95SE MTX, (AKA "The Road Rat"). Stock except for:TH fix, B.A.T. big brake kit, tranny cocktail and lots of re-insulated wiring! May yet be a 3.0! "Speed doesn't kill, stupidity does!"