> From: btufts@keps.kodak.com (Bob Tufts)
> bill comments:
>
> >the catalytic converter. If I'm correct so far, then the "pellets"
> >you see are probably the platinum balls which are a part of the
> >chemical process that "treats" the exhaust gases to lower the noxious
> >emmissions level.
>
> I append to the last sentence ",by creating obnoxious sulphur fumes!" :-)
> From: phile@pwcs.StPaul.GOV (Philip J Ethier)
> [...] In my experience, they are a fraud on the American people, and polute
> worse than an uncontrolled engine, but not with the polutants which are
> regulated. They probably are a major cause of acid rain.
Whoa!! Boy! Does this sound like anti-federal-gummint-don't-regulate-my-
car bashing!!
Think about it - platinum and ceramic are pretty inert materials. So, how
can they "create obnoxious sulphur fumes" or be "a major cause of acid rain?"
The answer is they can't - the sulphur has to come from the fuel! 'Tis true,
an improperly tuned or broken engine can run too rich, which will cause
more fuel to be oxidized in the catalytic converter, which also oxidizes
the sulphur into sulphur dioxide. The only difference is that with an
improperly running engine there is enough SO2 generated that you can smell
it - a properly running engine doesn't produce enough to notice (except
during warmup). But the point is: the sulphur is there, in a non-catalyst
car as well, whether you can smell it or not. (Some may argue here that
a non-catalyst car will not oxidize the sulphur to form SO2 directly,
which is true, but don't worry, sunlight and ozone will perform the conversion
eventually.)
So, Bob & Phil, my claim to you is that catalytic converters are a Good
Thing. The main purpose of the catalyst is to reduce the amount of
unburnt hydrocarbons that get emitted from imperfect gasolene engines -
unburned hydrocarbons being the major component of photochemical smog.
A catalyst does a much better job of this than any of the other means of
reducing hydrocarbons - allowing "modern" engines to run much better,
be much more efficient, and have much more power than an equivalently
"clean" (or "dirty," if you prefer) engine without a catalyst. (To
become a beliver in this, go out and find a '75 Crysler product with
a pre-catalyst "lean burn" engine and *try* to drive it - though you will
probably have a problem finding one - they were so undrivable that the
previous owners have probably run them off of a cliff or pounded them into
oblivion by now.)
Sheesh!
Pat Vilbrandt John Fluke Mfg. Co., Inc. Everett, Washington USA
UUCP: pwv@tc.fluke.COM or: { uunet, uw-beaver, sun, microsoft }!fluke!pwv
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