Jon Senior jon_AT_restlesslemon_DOTco_DOT_uk said:Andy Hewitt [email hidden] opined the
following...
Quoted message said:It's even worse than that for cars. Catalystic
converters are one of the biggest loads of [censored] there
are for reducing emissions. For a start CO2 is
*increased* by the cat, as it's one of the main
byproducts in getting rid of the other gasses (NOx is
one of them). Oxygen is *consumed* by the cat in order
to create the CO2. Indeed the only good byproduct of the
cat is pure H2O. Although that only increases corrosion
in the exhaust, and therefore increased need for
replacements.
I can't help feeling that you've missed the point of Cat
converters here. Of course they create more of one gas
while reducing another. It'd be impossible to get rid of
them altogether. The main aim however, is to remove the
more immediately toxic gases (CO - for example) by
conversion to less toxic ones (C02). The aim was never to
make them better for the environment as a whole, just for
people (And other animals in passing). The immediate harm
of carbon monoxide far outweighs the oxygen shortage
created.
Actually, it's not impossible to eliminate emissions, it's
just not cost effective.
FWIW, catalysts are nothing more than a convenient way to
reduce emissions at a very localised level. However, we now
have chemicals in use that we *know* are
poisonous/carcenogenic - i.e. benzine, instead of the ones
that simply *might* have been poisonous, but nobody had any
hard facts to prove - i.e. lead.
It is in fact possible to produce a car that has emissions
that are not toxic without a cat fitted at all.
I have a bit of knowledge of Honda cars, and IMHO they are
the pinnacle of engine design, and have some of the cleanest
engines around.
In 1972 they designed, and used in mass production an engine
(CVCC) that produced emissions to exceed the Californian
regulations of the time. It didn't have a cat fitted.
In 1991 they produced a derivative of the VTEC engine (VTEC-
E) that produced gasses that were cleaner than *any* other
car with a cat fitted. Indeed, the EU regulations that
followed meant they had to fit a cat, which actually
*increased* the poisonous emissions from this engine.
Both of these were standard production family cars that were
priced at competitive levels, so were available to all.
Quoted message said:Quoted message said:To cap it all, there is more pollution caused in simply
finding the precious metals used in the cat than it will
ever save in its entire life on the car, and that's even
before we go into the pollution caused during
manufacture.
This I agree with entirely. Although precious metal
(singular) since when I learnt about them, the catalyst
was platinum. ISTR that they can be recycled, but presume
that the cost is higher than simply using raw materials.
That's almost certainly the case, I would suspect the
benefits of using new are two fold: they are mined in third
world countries where labour is cheap, and it may be
politically beneficial to help these countries with some
foreign trade.
However, three precious metals are used in a modern cat, so
the pollution is actually three fold.
--
Andy Hewitt ** FAF#1, (Ex-OSOS#5) - FJ1200 ABS Honda
Concerto 16v: Windows free zone (Mac G5 Dual Processor)
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