Date:         Mon, 30 Aug 2004 08:23:52 -0700
Reply-To:     gary hradek <hradek@YAHOO.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         gary hradek <hradek@YAHOO.COM>
Subject:      emissions data
Comments: cc: jhecht@ALUM.MIT.EDU
Content-Type: text/plain; charset=us-ascii

Joy,
    It is interesting to consider that most cars do
most of their polluting in the first 5-10 minutes of
the drive.   I think if you give people knowledge you
can let them use it to make their choices.
   I think we can easily misrepresent things.
"Fuel cells are worse
because
synthesizing the hydrogen consumes more energy than
driving a regular
car
would."
There appears to be several forms of fuel cell
technology.   My current understanding is that one
uses gasoline as fuel and stips off hydrogen from the
hydrocarbon chain.   It does this at a relatively low
temperature by using a catalysis.   There is very
little waste heat which means more of the fuel is used
to produce force or movement.   No burning occurs so
there is no need for a radiator.
   Imagine that, a vanagon with a fuel cell, electric
motor and no bleeding.   Someone on the list will do
this someday.   Someone younger with imagination,
             regards gary

Date:    Mon, 30 Aug 2004 08:24:27 -0400
From:    Joy Hecht <jhecht@ALUM.MIT.EDU>
Subject: Re: emissions data

:::-----Original Message-----
:::From: Vanagon Mailing List
[mailto:vanagon@GERRY.VANAGON.COM] On
Behalf
:::Of gary hradek
:::Sent: Monday, August 30, 2004 12:26 AM
:::To: vanagon@GERRY.VANAGON.COM
:::Subject: emissions data
:::
:::Jon,
:::   No numbers for you just concepts.   Most fuel
:::injection engines run about the same.   It is the
Cat
:::that scrubs out the pollutants.   The nuber of
valves
:::an engine has also helps clean thing up a bit.
New
:::engines have a new rating of low emission and ultra
:::low emission largely do to the newer controls.
:::None of this will change the amount of co2
emission.

Actually, that's not quite right.  CO2 emissions are a
linear function
of
gasoline burned, so improving fuel efficiency reduces
CO2 emissions.
So
diesels are better than regular engines - but they
emit a lot more
particulates and other pollutants.  That's why hybrids
 - the SULEVs
(super
low emissions vehicles) - are looking good these days,
pending concerns
about life cycle impacts (battery disposal).  Fuel
cells are worse
because
synthesizing the hydrogen consumes more energy than
driving a regular
car
would.


Joy




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