[mdlug-discuss] Ethanol vs gasoline economy [Was: [mdlug] Automotive technical info ...]

[Robert Meier]

Aaron,

>>      Ethanol is a wonderful fuel - provided that it is recognized for 
>> what it is, designed for, and budgeted for. ...
> Wrong. [Ethanol is] designed for gasoline, ...

If I understand your context,
you are stating that ethanol is converted to gasoline and the gasoline
used as fuel.

I understand ethanol (C2H5OH) is not
gasoline (a mixture of CxHx, approximating C8H18)



So far as I am aware,
the debate described by the United States major media during the last year
is:
     to what extent our transportation system components should be
        converted/replaced to use ethanol as fuel,
and is not:
     to what extent ethanol should be converted to gasoline.

Positives:
It is my understanding that converting engine designs to ethanol is relatively
inexpensive and consists mostly of selecting insoluble materials,
designing components for a broader range of speed and torque,
and adjusting timings.
Because ethanol can be distilled/refined from local waste products,
incremental energy consumed in acquisition, transport, and delivery
to customer is less than gasoline.

Negatives:
I understand that because ethanol contains less chemical energy
(Gibbs Free Energy?) per unit volume, it theoretically can only provide
about 65% of the energy per volume that gasoline does.
I understand burning ethanol produces formaldehyde, a known toxin,
and it is difficult/expensive to avoid producing formaldehyde from ethanol.

Unknowns:
I understand there is disagreement on the economical methods and
incremental energy cost of ethanol distillation/refinement,
as well as disagreement on the cost and efficacy of reducing pollutants
like formaldehyde from burning ethanol.



I have not heard any debate on chemically converting ethanol to gasoline
but as a physicist, my uninformed (e.g. non-chemist) intuition
suggests that chemically converting local waste into gasoline (CxHx)
would be the most energy positive system, though still not enough
to supply projected transportation needs from terrestrial sources.



Inquiring minds want to know,
-- 
Dr. Robert J. Meier