Topic: Turning water into gasoline? (Read 969 times)
This could be a good way to store and transfer "excess" energy. For everything else it's too expensive.
If you're going to produce fuel from energy, you might as well produce hydrogen -- it's more efficient and burns more cleanly.
It's neither. Compressed hydrogen gas has 5-10 times less energy density than liquid hydrocarbon fuels, and is more dangerous to store. Even liquid hydrogen has a lower energy density than any liquid hydrocarbon, and you'd have to be crazy to keep it lying around. When it comes to efficiency of storing and transporting energy, hydrocarbons can't be beat (except by nuclear power, but that has its own problems).While it is technically true that hydrogen burns more cleanly, producing it is definitely not clean. Methane reformation (the most common industrial method) produces both carbon monoxide and carbon dioxide. ....
In general, LIQUID fuels have far greater utility than gaseous fuels. Which is why I like the potential of methanol produced through methane reformation.
And that is likely the most cost effective method of producing a useful liquid fuel.
But "gas from water" certainly sounds cooler.
If you're going to produce fuel from energy, you might as well produce hydrogen -- it's more efficient and burns more cleanly.
It's neither. Compressed hydrogen gas has 5-10 times less energy density than liquid hydrocarbon fuels, and is more dangerous to store. Even liquid hydrogen has a lower energy density than any liquid hydrocarbon, and you'd have to be crazy to keep it lying around. When it comes to efficiency of storing and transporting energy, hydrocarbons can't be beat (except by nuclear power, but that has its own problems).While it is technically true that hydrogen burns more cleanly, producing it is definitely not clean. Methane reformation (the most common industrial method) produces both carbon monoxide and carbon dioxide. Water electrolysis (the other method) requires vast amounts of energy. By contrast, the Fischer-Tropsch process consumes carbon oxides, though of course the carbon is released when the fuel is burned, making the whole process carbon-neutral except for the energy input. In both cases, the manufactured fuel is exactly as clean as the energy source that produced it.
For the very same reason we find it so useful to convert fuels into water and carbon dioxide, the reverse is not particularly useful. If you're going to produce fuel from energy, you might as well produce hydrogen -- it's more efficient and burns more cleanly.
Though it was some sort of error, but if it possible from that particular combination due simply to chemistry impressive.
The chemistry is not impressive at all. Water and carbon dioxide are the products of hydrocarbon combustion, along with energy. Reversing that process by putting energy back in (on an industrial scale, as opposed to a laboratory experiment) is certainly an impressive feat of engineering, but there's nothing special or exciting about the chemistry. (Emphasis added because I guarantee some people are going to misunderstand this point and think this is a source of free energy or free fuel. It isn't. You have to put in more energy to make the fuel than you get by burning it.)That said I wonder if it would work for space colonies, that said I think the modest Solar Panel doesn't get the props it deserves.
It would work, but what use would a space colony have for hydrocarbon fuel? Hydrocarbon fuels are useful on Earth because they have a high energy density and are easily transported in bulk over vast distances, but a space colony has no need to transport its energy anywhere, except perhaps as rocket fuel, but pure hydrogen has higher specific impulse, which is more important in rocketry than energy density. 
There is one big lesson that this article teaches. The media is mostly wrong.
http://rt.com/news/209619-sunfire-water-synthetic-fuel/
Quote
The German company says it has developed an engineering installation capable of synthesizing petroleum-based fuels from water and carbon dioxide. The ‘power-to-liquid’ rig converts gases extracted from water into liquid hydrocarbon fuels.
Though it was some sort of error, but if it possible from that particular combination due simply to chemistry impressive.
However, the F-T fuel technology “will always be more expensive” than getting conventional liquid hydrocarbon fuels from oil or coal, Aldag warned.
“What is important is that the value creation happens at the place where you use the fuel,” he said. So there will be no crude oil transportation costs and expensive infrastructure. “You are producing the fuel right where you are actually going to use it,” Aldag stressed.
That said I wonder if it would work for space colonies, that said I think the modest Solar Panel doesn't get the props it deserves.
As usual the press gets it wrong, while interesting this is the kind of thing you do with hydrogen fuel cells and to a lesser extent it has also been done with micro-organisms that absorb sunlight and excrete ethanol etc. I do think we're going to see a lot more of this technology that can take out hydrogen from water because it's extremely common, it just needs to be cheaper.
http://rt.com/news/209619-sunfire-water-synthetic-fuel/
Quote
The German company says it has developed an engineering installation capable of synthesizing petroleum-based fuels from water and carbon dioxide. The ‘power-to-liquid’ rig converts gases extracted from water into liquid hydrocarbon fuels.
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