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

[Aaron Kulkis]

Robert Meier wrote:
> 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, ...
>>     
>
>   

Ethanol makes a great gasoline additive.
It makes a lousy motor vehicle fuel in  and of itself.

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

No.  There are some engines optimized for ethanol as opposed to 
gasoline, but you have
all the attendant problems of ethanol (adsorbs water like crazy; even 
when dry, has much
lower energy density (BTU/gallon) than gasoline, etc).

> 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 think it's based on a lot of wishful thinking by people who don't 
understand the
thermodynamics, (i.e. McFuel is McFuel mentality), nor the economics (corn
prices are going through the roof -- to the point at which livestock 
farmers can't
afford it for cattle and pigs anymore, and well, burning food as vehicle 
fuel is just
plain crazy.

>
> I have not heard any debate on chemically converting ethanol to gasoline
>   

I'm not sure why you thought I suggested such a thing ...   oh well.


> 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,
>