Re: Older motorcycles and ethanol

On Mar 7, 12:08 am, Timberwoof <timberwoof.s...@xxxxxxxxxxxxxxx>
wrote:
In article
<3b36b48e-83e9-43d1-9521-4ba572a9f...@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
 Bruce Richmond <bsr3...@xxxxxxxxxxx> wrote:





On Mar 6, 9:07 am, Bob Mann <B...@xxxxxxxxxxx> wrote:
On Wed, 5 Mar 2008 20:34:38 -0800 (PST), Bruce Richmond

<bsr3...@xxxxxxxxxxx> wrote:

Back when they first mandated oxygenated fuels the idea was that the
extra oxygen would lean out the mixture on the old carborated bombs
that generally ran rich to begin with.  That would result in fewer
unburnt hydrocarbons in the exhaust.  Modern fuel injected cars have
an oxygen sensor in the exhaust that allows the adjustment of the fuel/
air mixture on the fly.  In recent years the reason for ethanol has
shifted to displacing fossil fuel.  IMHO it is PC BS.  In practice as
much CO2 is put into the atmosphere distilling the ethanol as would
have been put in by burning gasoline in the first place.  The ethanol
just makes it a PITA for those that were properly jetted for straight
gasoline.

Bruce

I'm not sure what the net effect on the envirinment is but alcohol
does burn cleaner and while the future fuel is growing it does add
oxygen to the atmoshpere as long as trees aren't displaced to grow it.

Unless you are using some unusual definition for cleaner alcohol does
not burn much if any cleaner than gasoline.  Both result in CO2, CO,
H2O, and NOx.  Ethanol has less carbon in it so there will be less CO2
and CO, but neither makes any soot when mixed in the correct fuel/air
ratio.  An engine optimized for E85 has a higher compression ratio
than used for gasoline and will result in an *increase* of NOx
output.  NOx is the primary cause of acid rain.

Higher peak temperatures are what cause increased NOx emissions.

Yes, and a higher compression ratio gives higher peak tempertures.

Current practice is to use fossile fuels to produce the heat for
distilation of ethanol.  So long as that practice continues ethanol
does nothing to reduce our dependence on fossil fuel or the build up
of CO2 in the air.  There are other ways of distilling it, but they
are currently the exception not the rule.

The question also becomes one of whether you displace food grade corn
with fuel grade corn.

Corn stinks for ethanol production.  By the time you get done you only
get out 1.3 times the energy you put in.  

That sucks.

Sugar cane puts out 8 times
the energy put in.  There are wild grasses that put out better than
the 1.3 figure, and they don't require cultivation like corn.  There
is no question that the diversion of corn has caused food prices
including meat to go up.

There is an argument to reduce import duties on sugar so that it can be
used for this purpose.


If we are going to import why not just import the ethanol? Brazil
will sell it to us for less than it costs us to make it. They use the
waste from the cane as fuel for the distilation process. There are
currently high duties on the importation of ethanol. We have a sugar
cane crop in the US, but because of current laws it can't compete with
corn. Go figure.




I think they should be looking at ways to make methanol more
environmentally friendly.

Why?  It is less of a solution than ethanol.  The primary means of
producing it is by reacting natural gas and steam with a catalyst.
IOW you are still burning a fossil fuel.  If you have ever been around
an engine burning methanol you would know that it brings tears to your
eyes.  It is nasty stuff and very corrosive.  It also gives *** for
fuel mileage.  A stochiometric mixture for methanol is 6.4:1 meaning
you would get less than half the miles per gallon you get with
gasoline.  Ethanol has a stochiometric mixture of 9:1 resulting in 34%
fewer mpg than gasoline.

http://en.wikipedia.org/wiki/Stochiometric

http://en.wikipedia.org/wiki/Methanol

http://en.wikipedia.org/wiki/Ethanol

I'm not certain I believe your correlation between fuel mixture and fuel
consumption. Can you provide a link for that?

You will find the 34% less for ethanol here

http://en.wikipedia.org/wiki/Ethanol_fuel

just below "Ethanol-based engines"

For methanol go to

http://en.wikipedia.org/wiki/Ethanol

and find the chart about half way down that gives energy content for
various fuels. It lists gasoline at 34.8 MJ/L, ethanol at 23.5 MJ/L
and methanol at 17.9 MJ/L. Divide 23.5 by 34.8 and you get 67.5% or
32.5% less energy for ethanol vs gasoline. That is close to the the
34% mentioned above. Do the same for methanol and you get 17.9
divided by 34.8 equals 51.4% or 48.6% less than gasoline. It takes
the same energy to go a mile reguardless of the fuel, so methanol will
get about half the mpg.

<snip>

--
Timberwoof <me at timberwoof dot com>
faq:  http://www.timberwoof.com/motorcycle/faq.shtml
Ten Steps to Fascism:http://www.guardian.co.uk/usa/story/0,,2064157,00.html- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

.

Loading