Gas with ethanol

Can we use gas with alcohol added in our aircooled bike engines?

 

You're quite right. Perhaps people get these weird ideas because Ethanol
is hygroscopic, and has been known to cause corrosion in fuel system
components -- esp. on older vehicles which were designed before it became
a common fuel additive.

 

Champ/IRL cars have run on methanol since the stone age. YMMV.

When you say the heads pitted, where precisely? Water and
its electrolytes are probably more corrosive than alcohol.

 

What is the actual difference between Methanol and Ethanol in application?
-----
First up Methanol is toxic and Ethanol is basically grain alcohol but
denatured (made mildly toxic trying to keep people from drinking it).
Next is the ratio of air to fuel. Pure ethanol runs about 200% or twice
as much liquid as regular gas. Methanol runs about 300%. For fixed jet
(normal carbs) engine the change to adding alcohols (to gasoline) has
both increased the octane rating (pressure/temperature when detonation
occurs assuming a correct mixture) and leaned your engine (you need
more liquid fuel for a given amount of air).

If you have fuel injection and an oxygen sensor no worries just your
mileage went down. For us early bike owners we've jetted with bigger
jets. Now for people with cars and bikes with fixed jets, well if you
were running rich you might be fine, but otherwise your power is off
and you find yourself buying supreme to avoid detonation even at 8.5:1
compression ratios.

 

Interesting articles on that site. I was strolling around Hollywood one
day and noticed a smaller gas pump with an "out of service" sign
sitting on a pad by itself, so I was curious and went over to look at
it. It was a methanol pump! The octane sticker said that it was only
108 octane though. Maybe it was a blend of a little methanol with a lot
of gasoline? I dunno. It seems like a few of the major manufacturers
had "alternative fuels" cars several years ago. and the service
stations had to supply fuel at certain stations. It was the only
methanol pump I've ever seen.

 

Pearson Ford in San Diego has a service station that sells all kinds of
fuels, including ethanol. Some cars can take it -- if you open your gas
tank cover and there's a wheat symbol, your car can use it. IIRC, it
was mostly recent model Ford cars that were ethanol-compatible.

Rich, Urban Biker

 

IIRC: the biggest problem with alcohols as fuels is they cost so much
energy to produce and don't store
energy as effectively as gasoline. (I am not an expert at energy
management, so I will defer to any
experts in the group). We tend to think of fuels as energy 'sources'
because ... well, at the time of
buring them there are. But they had to be made -which requires
energy... this includes petroleum:
it was made by biological and geological processes (ie. biomass getting
buried and cooked in the
absence of oxygen). Earth's petroleum reserves contain the results of
millions of years of
photosynthesis - and although they are technically 'renewable' we are
using up the petroleum faster
than nature makes it.

Anyway onto alcohols: they can be made by chemical or biologucla
processess. The latter being better
because all we have to do is feed some microbes and have them churn out
fuel. Right? Wrong. The
food has to be produced (which uses chemicals and energy) and then the
alcohol has to be extracted.
Ironically, most comercial fertilizers are made with/from petroleum so -
it takes oil to grow the corn
to be used to replace gasoline! If you consider corn ethanol as a
fuel - the energy to fertilize, grow,
harvest and transport the corn is considerable - and currently these
rely heavily on oil!

OK, let's ignore the growing of the corn: there is a 'free'
fermentation process - well yeast eat the sugars
in the corn and produce alcohol. Still, we have to distill the liquid
to extract ethanol. If we assume the
left over liquid is 20% ethanol by volume (which is very hard to do in
mass production) then you have
to boil 5 gallons of liquid to extract 1 gallon of ethanol (this is a
best case scenario - 10-20 gallons are
more likely!) Go to your chem books and see how much energy is rquired
to boil 1 gallons of water
(OK, this isn't exactly right but it gives you an idea of how energy
expensive it is to extract ethanol).
[Cracking oil is a comparable process, insofar as it requires a bunch of
heat, but unlike distilling
alcohol, there are uses for the other petroleum products. No one wants
the boiled waste water.]

Now, consider that the energy content in Ethanol is considerable less
(by this I mean, BTUs/Gallon)
so you need a bigger gas tank to go as far as with Gasoline. There is
a reason that Ethanol is not a
viable fuel today. In fact, there is a reason that the oil execs
aren't pushing us toward Ethanol fuel!


Now, if you think alcohol is bad - Hydrogen as a fuel is even worse!!
It isn't grown by sunlight,
we have to break apart molecules to make Hydrogen. OTOH: if we're smart
we break the molecules and
extract H2 all in one go. If we use solar power to do this, we may be
able to 'store' solar energy with
Hydrogen (but remember the amount of sunlight falling on the Earth is
about 1.3 kW/m^2 - IOW one
square meter of sunlight, if used 100% efficiently, could power a hair
dryer. It will take an awfull lot
of solar cells to collect enough energy to power our cars)

The problem is the energy content in a scuba tank full of compressed
Hydrogen (stuff as much
as you can in there) isn't all that much. Plus, your 'gas tank' weighs
more than the fuel. (never mind the
danger of getting into an accident with a flammable compressed gas in
every car). If you could safely
store liquid Hydrogen - THEN we'd have a great solution (but that has
other problems)

BTW: I found this table on-line. Energy content per kilogram of certain
fuels

Net Energy Content
MJ/kg
Hydrogen 120
Methanol 19.95
Ethanol 26.68
MTBE 35.18
Gasoline 42 - 44




IIRC: 1 MJ = 1,000 BTU = 0.29 kWh = .4 Hp hours