Daily Mail: US Navy Invents Process For Turning Sea Water into Jet Fuel for... $3-$6 per Gallon?!?

You can read all the "game changing" type hype at the article.

Here's how it works, supposedly:

The [Navy Research Labs] process begins by extracting carbon dioxide and hydrogen from seawater.

As seawater passes through a specially built cell, it is subjected to a small electric current.

This causes the seawater to exchange hydrogen ions produced at the anode with sodium ions.

As a result, the seawater is acidified.

Meanwhile, at the cathode, the water is reduced to hydrogen gas and sodium hydroxide is formed.

The end product is hydrogen and carbon dioxide gas, and the sodium hydroxide is added to the leftover seawater to neutralize its acidity.

In the next step, the hydrogen and carbon dioxide are passed into a heated reaction chamber with an iron catalyst.

The gases combine and form long-chained unsaturated hydrocarbons with methane as a by-product.

The unsaturated hydrocarbons are then made to form longer hydrocarbon molecules containing six to nine carbon atoms.

Using a nickel-supported catalyst, these are then converted into jet fuel.

Hydrocarbons -- fossil fuel molecules -- are basically just chains or rings of carbon atoms, say 6 to 18 carbon atoms long, each carbon atom in turn connected to 2-3 hydrogen atoms.

Ummm... it seems so game-changing as to be paradigm-shifting -- suddenly we have as much high-power jet fuel as we have gallons of ocean -- that it's hard, bordering on impossible, to believe.

Here's the harder to believe part: This process would be almost carbon dioxide neutral. It's true, of course, that upon burning the jet fuel, you'd turn it into carbon dioxide and water atoms (as you do whenever you burn a fossil fuel).

However, in this process, the carbon in the fuel is being extracted from sea water in the first place. That carbon dioxide gas is just atmospheric carbon dioxide, dissolved into liquid.

So while you are liberating carbon dioxide gas at the end of the process, it's just carbon dioxide gas you previously sucked out of the hydrosphere in the first place.

More or less a neutral, one carbon dioxide atom liberated for each carbon dioxide atom consumed process. I'm sure that you'd add some carbon dioxide, as you'd have to burn some energy to catalyze this whole process. (I suppose you could avoid that by setting up nuclear reactors that did nothing but provide electricity for this jetfuel-from-seawater process.)

I don't particularly care about that. I guess maybe that makes me extra-special-skeptical -- I know that any energy source claiming to be nearly carbon-neutral is going to get extra hype and lots of funding.

But who knows. I don't.

via @rdbrewer4.

posted by Ace at 05:59 PM

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