Slashdot Mirror

← Back to Stories (view on slashdot.org)

US Navy Tries To Turn Seawater Into Jet Fuel

Posted by samzenpus on from the ocean-in-the-tank dept.

Hugh Pickens writes "New Scientist reports that, faced with global warming and potential oil shortages, the US Navy is experimenting with making jet fuel from seawater by processing seawater into unsaturated short-chain hydrocarbons that with further refining could be made into kerosene-based jet fuel. 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, a variant of a chemical reaction called the Fischer-Tropsch process, which is used commercially to produce a gasoline-like hydrocarbon fuel from syngas, a mixture of carbon monoxide and hydrogen often derived from coal. The Navy team have been experimenting to find out how to steer the CO2-producing process away from producing unwanted methane by finding a different catalyst than the usual one based on cobalt. 'The idea of using CO2 as a carbon source is appealing,' says Philip Jessop, a chemist at Queen's University adding that to make a jet fuel that is properly 'green,' the energy-intensive electrolysis that produces the hydrogen will need to use a carbon-neutral energy source; and the complex multi-step process will always consume significantly more energy than the fuel it produces could yield. 'It's a lot more complicated than it at first looks.'"

6 of 402 comments (clear)

  1. But the beauty is by Brett+Buck · · Score: 5, Insightful

    the energy-intensive electrolysis that produces the hydrogen will need to use a carbon-neutral energy source; and the complex multi-step process will always consume significantly more energy than the fuel it produces could yield. '

            But it's easy to put a nuclear reactor in a ship, and not so easy to put one in a fighter jet.

            Brett

    1. Re:But the beauty is by lgw · · Score: 5, Insightful

      The obvious application here is for a (nuclear-powered) aircraft carrier to make fuel for the aircraft that it carries. So wave power and the like might be interesting in a civilian offshoot of this tech, but the Navy has nuclear power to start with.

      In civilian use, many of the most efficient engines in commercial use are diesel-electric. Gas-electric hybrids aren't quite as efficient yet, but probably will be soon. Turning non-fossil-fuel-based electric power (whether nuclear, wave power, unicorn giggles, or whatever the hippies will finally accept) plus CO2 into gas or diesel fuel, then burning that fuel in a car in a normal way to drive around is carbon neutral, and works with existing cars and existing refueling stations.

      This would seriously kick ass as a way to break dependency on non-renewable fossil fuels but still use the same cars we drive today. 100% win IMO. Of course, there are people whe really just hate gas engines, and only pretend to care about CO2 and renewable resources and so on, but you can never make everyone happy.

      --
      Socialism: a lie told by totalitarians and believed by fools.
    2. Re:But the beauty is by Rogerborg · · Score: 5, Insightful

      fighter jets don't have easy access to seawater anyway..

      Carrier based jets have very easy access to seawater. Once.

      --
      If you were blocking sigs, you wouldn't have to read this.
  2. Makes sense by seifried · · Score: 5, Insightful

    Nuclear powered aircraft carrier, so you've got a pretty good supply of energy there, being able to convert electricity into jet fuel would save them money and reduce the amount of fuel they have to carry (reducing the amount of flammable liquids held in a ship that might get hit by a missile), and could end the need to resupply fuel, all in all very sexy if you're going in to combat.

  3. You're missing the point. by Anonymous Coward · · Score: 5, Insightful

    This has got nothing to do with creating free energy, and it's got nothing to do with environmentalism. It's all about military strategy.

    Your nuclear-powered carrier fleet is on patrol in a war zone. Resupply convoys are a risky business. How do you keep your planes in the air without a constant supply of jet fuel?

    You make your own on board. Who cares if it's "thermodynamically a huge waste"? You've got a freaking NUCLEAR REACTOR. It's got plenty of energy to spare, all you gotta do is repackage that energy into a form that can be poured into an aircraft fuel tank.

  4. Re:Cost effective? by pluther · · Score: 5, Insightful

    By the time there is no oil left for navy ships, I am betting another fuel source will have come along

    You mean, like maybe the Navy might find a way of turning seawater into jet fuel?

    --
    If the masses can keep you down, you're not the Ubermensch.