If you’re getting twitchy about the uptick in petrol prices, spare a thought for the US Navy: fighter jets don’t just fuel themselves while parked on those aircraft carriers, y’know. But what if those same aircraft carriers could suck up seawater and catalyse it into aviation fuel?
Navy chemists have processed seawater into unsaturated short-chain hydrocarbons that with further refining could be made into kerosene-based jet fuel. But they will have to find a clean energy source to power the reactions if the end product is to be carbon neutral.
Nuclear-powered carrier? Sorted. So how does it work?
The process involves extracting carbon dioxide dissolved in the water and combining it with hydrogen – obtained by splitting water molecules using electricity – to make a hydrocarbon fuel.
In the conventional Fischer-Tropsch process, carbon monoxide and hydrogen are heated in the presence of a catalyst to initiate a complex chain of reactions that produce a mixture of methane, waxes and liquid fuel compounds.
Dorner and colleagues found that using the usual cobalt-based catalyst on seawater-derived CO2 produced almost entirely methane gas. Switching to an iron catalyst resulted in only 30 per cent methane being produced, with the remainder short-chain hydrocarbons that could be refined into jet fuel.
Heather Willauer, the navy chemist leading the project, says the efficiency needs to be much improved, perhaps by finding a different catalyst.
There you go – once those niggling little details are out of the way, you’ve got yourself an aircraft carrier that doesn’t need to pick up fuel for itself or its complement of aircraft, and hence doesn’t need to return to base for years (provided they can scrounge up food for the sailors and pilots in whatever theatre of operations they’re in at the time, natch).
But now imagine that it goes rogue… or someone manages to hijack it, Somali pirate style, only with no intention of ransoming it – why get rid of your own private strike-force-equipped floating nation-statelet, after all? [image by Serendigity]
Regular readers may note I’m becoming vaguely obsessed with the intersection of the oceans, geopolitics and sustainable technologies. I’m no Bruce Sterling, but I’m still confident in my assertion that plenty of weird stuff will be happening on the high seas in our not-so-distant future.