[Harry vdG]

Potentially, Europe could be covered with efficient wind turbines. Electricity would then
be redundant. We still need fuel for heavy transport, airplanes, and auxiliary power stations
in case of (unlikely windless periods over a (too) large part of Europe.

Hydrogene is well known in this respect. But it is by no means an efficient fuel: it either
must be compressed, or cooled to turn it in its liquid phase.

It would be much better to turn electricity, water and air into a hydrocarbon, or even NH3.
Could one think of electrolysis, in the presence of a catalyst, to create Methylal or Ethylal
from CO2 in the air, combined with water? If fuel could be created this way with a reasonable
efficiency, the use of fossil fuels could be halted in 2030.

This post has been edited by Harry vdG: 17 December 2011 - 09:49 PM

[DrRocket]

Harry vdG, on 17 December 2011 - 09:47 PM, said:

If fuel could be created this way with a reasonable
efficiency, the use of fossil fuels could be halted in 2030.

If frogs had wings they wouldn't bump their ass.

[mississippichem]

Harry vdG, on 17 December 2011 - 09:47 PM, said:

Potentially, Europe could be covered with efficient wind turbines. Electricity would then
be redundant. We still need fuel for heavy transport, airplanes, and auxiliary power stations
in case of (unlikely windless periods over a (too) large part of Europe.

Hydrogene is well known in this respect. But it is by no means an efficient fuel: it either
must be compressed, or cooled to turn it in its liquid phase.

It would be much better to turn electricity, water and air into a hydrocarbon, or even NH3.
Could one think of electrolysis, in the presence of a catalyst, to create Methylal or Ethylal
from CO2 in the air, combined with water? If fuel could be created this way with a reasonable
efficiency, the use of fossil fuels could be halted in 2030.

That chemistry is impossible. If it was possible, the thermodynamics are going the wrong direction, meaning you're doing work or putting energy in the system for no energy benefit. That process would be highly thermodynamically disfavored.

[John Cuthber]

Strictly speaking the chemistry is perfectly possible.
He explicitly states that we can use electricity to provide the energy.
I don't think it will be more efficient than using hydrogen as a fuel though.
Capturing CO2 from the air is expensive in energy terms.

Perhaps more importantly, as someone who lives in Europe, I'd not be happy seeing it covered with wind turbines.

What he means by "Methylal" and "Ethylal" is anyone's guess.
Probably not
http://en.wikipedia....imethoxymethane
and the corresponding diethoxy compound.

[Horza2002]

By methyal i guess he means methanal and ethanal...

[CaptainPanic]

The topic title mentions alcohols, so maybe he just means methanol and ethanol?

Making methanol from excess hydrogen is already commercial (see below), so if we assume that we are all happy with the windturbines (which is NOT the topic, so let's bicker about that in another thread), this is perfectly feasible and even economically interesting.

from wikipedia:

Quote

It is worth noting that the production of synthesis gas from methane produces three moles of hydrogen gas for every mole of carbon monoxide, while the methanol synthesis consumes only two moles of hydrogen gas per mole of carbon monoxide. One way of dealing with the excess hydrogen is to inject carbon dioxide into the methanol synthesis reactor, where it, too, reacts to form methanol according to the equation:

I totally agree with John Cuthber that extracting CO₂ from the air is extremely expensive and inefficient.

[immijimmi]

People are saying it's useless because there's no energy gain, but isnt it an alternative to electricity-powered planes? Plus, you're using greenhouse gases to make the HC in the first place so no net pollution! Basically, It means keeping fuel-powered engines, but with the benefits of electicity.

[CaptainPanic]

immijimmi, on 5 January 2012 - 07:52 AM, said:

People are saying it's useless because there's no energy gain, but isnt it an alternative to electricity-powered planes?

Assuming that (1) the fossil sources of energy run out, (2) the biomass technologies all fail, (3) energy density in batteries make only few advances, or none at all and (4) a plentiful supply of electricity from something sustainable... then yes, this would be an alternative to electricity powered planes.

immijimmi, on 5 January 2012 - 07:52 AM, said:

Plus, you're using greenhouse gases to make the HC in the first place so no net pollution! Basically, It means keeping fuel-powered engines, but with the benefits of electicity.

But if you power this reaction with electricity from a fossil source, you will put more CO2 back into the atmosphere than you remove from it, resulting in a net increase.

[Sorcerer]

I'm out of beer, I'm sticking my tounge in a light socket to see if you have something.

No but seriously, methanol could be a source of energy, but it would be far easier and far more efficient to perform electrolysis on water and produce hydrogen. I guess if u then combined this with CO^2 and a catalyst it could make methanol. But this would be heavier to transport.

IMO the most efficient way of using electricity as a fuel would be to just plug an electric car into the grid.

[Suxamethonium]

Actually, A more interesting way to think of this would be to apply it in bio-genetics. Plant cells that could produce alcohol by photosynthesis alone, cultivated using "solar farms" which could just as easily be the unused roof space of apartments and skyscrapers. The cells could also be used to fix nitrogen at the same time (also, provides nutrients for the cells as well as economical nitrogenous products). Would be more economical than fermenting corn/sugarcane especially grown for the fuel.

A little bit of a diversion, but I never quite understood where the thread was going in the first place. lol