[ExI] Liquid fuel

[Eugen Leitl]

On Mon, Jan 28, 2008 at 08:46:06PM -0700, hkhenson wrote:

> have come up with an interesting twist.  They make synth gas (a mix 
> of H2 and CO) out of anything organic.

You throw away most of enthalpy at that stage.
 
> Then they feed the gas to microbes in a bioreactor.  The bugs turn 
> the synth gas into ethanol.  There are other ways to turn synth gas 

You throw even more away here for bug metabolism, and destillation.

> into liquid fuels, but this method seems to be a significant improvement.

If you want liquid fuels, go for direct methane oxidation, and make
methanol (which can be directly convereted to electricity via
a non-Carnot process).

Humanity taps some one fourth to one half of entire planetary biomass.
This is a heavy burden already, and we can't afford to usurp even more
of the matter and energy flows.

In contrast to that, PV has no additional footprint, vastly higher
efficiency, and can power things directly, or be used to make fuels.
 
> An interesting aspect is that this method might lend itself to rather 
> small plants, down perhaps to the neighborhood scale or even a farm 
> family using crop waste.

I can see biogas plants from domestic waste. But the synthesis gas route
is a really stupid idea.

-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
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