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Power The Military Science

US Navy Tries To Turn Seawater Into Jet Fuel 402

Posted by samzenpus 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.'"
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US Navy Tries To Turn Seawater Into Jet Fuel More

US Navy Tries To Turn Seawater Into Jet Fuel

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  • Or... (Score:3, Funny)

    by detox.method() ( 1413497 ) on Thursday August 20, 2009 @12:53AM (#29129631)
    ...they could just hire Jesus.

  • But the beauty is (Score:5, Insightful)

    by Brett Buck ( 811747 ) on Thursday August 20, 2009 @12:57AM (#29129647)

    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

    • Re:But the beauty is (Score:4, Interesting)

      by Manip ( 656104 ) on Thursday August 20, 2009 @01:21AM (#29129761)

      Plus low carbon energy isn't that much of a fools dream...
      I mean there are some really great designs for wave power floating around right now (yes, pun intended). Plus wind has some potential.

      But even if we fed all the countries of the world on carbon free electricity and all had electric cars, we'd still need planes and jet engines in particular.

      We could potentially build an electric jet engine-replacement (giant air compressor?), but until batteries become a lot lighter that would obviously be very counter-productive.

      • Re:But the beauty is (Score:4, Interesting)

        by digitalunity ( 19107 ) <(digitalunity) (at) (yahoo.com)> on Thursday August 20, 2009 @01:55AM (#29129927) Homepage

        Weight itself isn't the issue, it's energy density and max instantaneous energy output.

        Even if you could make a 1,000,000 amp-hour battery, it's useless if it's internal serial resistance is too high to provide the amperage needed. Conversely, a low ESR capacitor can deliver quite a punch, but not for long enough to drive a jet across the country.

        A gazillion dollars a year are spent on developing new battery technologies. One day they might rival the density of gasoline but I'm not holding my breath any time soon.

        • Well, the main difference between batteries and gasoline is that once you've spent all the energy in the gasoline, it's really not that easy refilling it. After all, you've consumed it. Not so much with the batteries.

          No clue what kind of energy you could extract from a fully loaded battery pack if you were allowed to consume the battery itself, but it'd be higher than otherwise.

          • Re:But the beauty is (Score:5, Funny)

            by Anonymous Coward on Thursday August 20, 2009 @03:05AM (#29130231)

            Yeah, but I've come up with this brilliant idea for that. See, up until now, gasoline powered devices come with all their gasoline installed at the factory, like you said, and once the gasoline is gone, you have to throw out your car/lawnmower/Molotov cocktail and get a new one. But, my brilliant idea involves a hole in the gas tank through which you can pour more gasoline. I know, I know, it sounds crazy. Who would want a hole in the side of their car? Plus, all your gas would evaporate, it would be dangerous, etc. But the hole is only part of my ingenious plan. I've come up with a threaded stopper for the hole that you can screw into it to seal it. Plus, a little door to go on the side of the car with the gas-hole behind it, to make it unobtrusive. There are some big obstacles to my plan though. This revolutionary idea is going to require a huge investment. We're going to need to put gasoline pumps everywhere, at what I call a "filling station". It's going to take some time to get everything set. Still, I think it will be worth it.
            On a side note, the obvious advantage that volatiles like gasoline have over batteries in terms of energy density is free oxygen. The energy density of gasoline isn't worth squat in space, for example. It needs plenty of oxygen to work, but you don't have to carry the oxygen with you. If you had to lug around an oxygen canister with the gasoline to make it work, batteries might become much more attractive. This is why fuel air explosives give so much bang for the buck. It's harder to make the process work than conventional explosives, but you don't have to pack the fuel air bomb with its own oxidant.

            • I like the humor in your post but I think the parent comment wasn't really concerning not being able to refill the gas tank, it was about the density of the batteries compared to the bulk of the containment. If batteries could be consumed completely much like Gasoline could be, then the energy density could increase greatly. Again, your concept of a hole with a door covering it comes in real hand for refueling the batteries too.

              Now to make sure you understand this concept, I'm going to ask you to imagine so

        • Re: (Score:3, Interesting)

          by lupine ( 100665 ) *

          The cool thing about electric cars is that they are so much more efficient that you don't need batteries that are as energy dense as gasoline. The tesla roadster has a range of 240miles with a battery pack that holds 53kWh. A gallon of gas has the energy equivelent of about 35kWh. So a tesla can go 240 miles on only 1.5 gallons of gas. This is because the battery and motor are so much more efficient than an internal combustion engine which wastes most of the gasoline energy as heat.

          So in order to build awes

      • Re:But the beauty is (Score:5, Insightful)

        by lgw ( 121541 ) on Thursday August 20, 2009 @02:04AM (#29129977) Journal

        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.

        • Can't that "non-fossil-fuel-based electric power" alone propel the car? Why do we need to make more fuel, resulting in more emissions, and poor energy conversion efficiency?

          • Re:But the beauty is (Score:5, Informative)

            by Rogerborg ( 306625 ) on Thursday August 20, 2009 @03:40AM (#29130407) Homepage

            Can't that "non-fossil-fuel-based electric power" alone propel the car? Why do we need to make more fuel, resulting in more emissions, and poor energy conversion efficiency?

            What part of "works with existing cars and existing refueling stations" is confusing you hippes?

            There's only recently been an announcement [gas2.org] of a standard plug for electric cars. Note that an "announcement" is not manufacturing, or even a commitment to manufacturing. We've still got the inevitable patent wrangles, the embrace-extend debacles, breakaway standards, and the litigation and class action suits to go before we'll have a standard plug, and then we have to build the charging infrastructure, on top of a creaking already over-strained electrical grid.

            Sorry, I put far too much thought into that. Try to read it really slowly.

            • Re: (Score:3, Insightful)

              by Chris Burke ( 6130 )

              What part of "works with existing cars and existing refueling stations" is confusing you hippes?

              The part where you act like this seawater-into-fuel tech is fully developed and deployed instead of just a Navy experiment, or like the "existing" auto fleet isn't already changing.

              There's only recently been an announcement of a standard plug for electric cars.

              And there was only just an announcement that the Navy is experimenting with creating jet fuel from seawater. But you're still arguing that EVs are in th

        • Re: (Score:3, Funny)

          by SnarfQuest ( 469614 )

          Yes, but they are going to need enormous amounts of water to plit off the hydrogen. Where are they going to get all this out in the middle of the ocean? They will need constant resupply ships just to supply all the needed water. You might just as well have the supply ships carry finished fuel instead of water.

    • Re:But the beauty is (Score:5, Insightful)

      by mpe ( 36238 ) on Thursday August 20, 2009 @05:03AM (#29130807)
      But it's easy to put a nuclear reactor in a ship, and not so easy to put one in a fighter jet.

      A nuclear powered aircraft carrier needs regular supplies of jet fuel, via ships which are easier to sink than a warship.
      Having a carrier able to produce fuel for its aircraft solves a major logistics issue as well as potentially freeing ships from escort/guard duty.

  • Makes sense (Score:5, Insightful)

    by seifried ( 12921 ) on Thursday August 20, 2009 @12:58AM (#29129649) Homepage
    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.
    • Even without cheap hydrocarbons. this has got to be a logistics wet dream. Carrier groups are hopelessly dependent on regular resupply.

    • Nuclear powered aircraft carrier, so you've got a pretty good supply of energy there

      Plenty of energy - not so much to spare once you account for propulsion, hotel loads, steam for the catapults, etc...

      being able to convert electricity into jet fuel would save them money and reduce the amount of fuel they have to carry

      Carriers are big, but they are stuffed full of what they need to fight - and fuel tanks are tucked into odd corners well below the water line. Not much spare room for the major

      • Re:Makes sense (Score:5, Informative)

        by NewbieProgrammerMan ( 558327 ) on Thursday August 20, 2009 @04:11AM (#29130575)

        Plenty of energy - not so much to spare once you account for propulsion, hotel loads, steam for the catapults, etc...

        Actually, most of the time the plant isn't loaded heavily at all--most of its capacity is there solely for moving at high speed. Since you don't do that very often (you get to wherever you're going and then putt around in little rectangles), there's plenty of power available for doing something like this.

        Carriers are big, but they are stuffed full of what they need to fight - and fuel tanks are tucked into odd corners well below the water line. Not much spare room for the major industrial plant required to produce sufficient fuel in a reasonable amount of time.

        For what it's worth, the one I was on had several not-too-small empty spaces, certainly enough to install small test plants. I'm sure if this turns out to be viable, newer ships could be designed with plenty of room for fuel generators.

      • So, Newport News will make them a hair bigger to accomodate.

        • Re: (Score:3, Insightful)

          by SDF-7 ( 556604 )

          Considering they're planning to try to get linear induction catapults in the Ford class -- I wouldn't be at all surprised if part of the A1B specification is a good chunk of surplus capacity. (Isn't the Navy also planning on moving to lasers for CIWS and railguns to replace 5"? Granted, not all that would come about -- but you'd have to think the Ford designers are complete morons not to plan a 50-year life span ship [and who knows how long in service class design as a whole] with surplus power for the proj

  • Trying to avoid Methane? (Score:3, Insightful)

    by MichaelSmith ( 789609 ) on Thursday August 20, 2009 @01:08AM (#29129695) Homepage Journal

    Methane is a good fuel in its own right. Using solar power this could be a good general source of transportable energy.

    • Indeed it is, but not as jet fuel; as a couple of other posters have pointed out, almost certainly what the Navy has in mind for this is a plant that could be put on board an aircraft carrier, and used to make fuel while at sea. Methane is waste in this scenario.

      • Re:Trying to avoid Methane? (Score:5, Interesting)

        by afidel ( 530433 ) on Thursday August 20, 2009 @01:33AM (#29129819)
        Exactly, it removes one of the biggest and most vulnerable pieces of the supply chain to a carrier group, fuelers for the aircraft. If this becomes a reality soon I think good old CVN-65 (Enterprise) may get a reprieve from retirement. There's nothing quite like the spare capacity in those 8 reactors to power something like this =)

  • Naval waste (Score:3, Insightful)

    by harvey the nerd ( 582806 ) on Thursday August 20, 2009 @01:29AM (#29129789)
    Thermodynamically a huge waste.

  • You're missing the point. (Score:5, Insightful)

    by Anonymous Coward on Thursday August 20, 2009 @01:48AM (#29129897)

    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.

    • Re:You're missing the point. (Score:5, Informative)

      by im_thatoneguy ( 819432 ) on Thursday August 20, 2009 @02:26AM (#29130069)

      And by my Google search estimates a carrier only has enough fuel for about 1,000 flights before exhausting its supply and needing a tanker.

      I imagine during combat operations that doesn't last terribly long. And having to pull along side another vessel and safely pumping that fuel has got to provide some pretty serious tactical limitations.

  • Energy intensive industry and wind power (Score:4, Interesting)

    by Michael Woodhams ( 112247 ) on Thursday August 20, 2009 @02:55AM (#29130187) Journal

    Wind power has lots of advantages, but one major drawback - it is intermittent. If you have an industry which is very energy intensive but has low capital cost, this presents an opportunity: build your plant, and run it only when the wind is blowing and power is very cheap. This works especially well if your product is easily storable.
    This process is clearly energy intensive and produces an easily storable product - whether it has the required low capital cost is much less clear. (Although the interest of the navy suggests they're wanting to use aircraft carrier nuclear power, but once developed it could find wind-powered civilian use.)
    Water desalination and aluminium smelting might also qualify (I don't know the capital costs of these). Recharging electric cars certainly does (given that you're buying the car anyhow), except that you have a very limited storage capacity.
    Despite not being low capital, data centres are even starting to go this way, being built with the intention of only running them when electricity is cheap (or less is required for air conditioning.) In this case the product is extremely transportable rather than easily storable.

    • Re:Energy intensive industry and wind power (Score:4, Interesting)

      by c6gunner ( 950153 ) on Thursday August 20, 2009 @03:18AM (#29130281) Homepage

      This process is clearly energy intensive and produces an easily storable product - whether it has the required low capital cost is much less clear. (Although the interest of the navy suggests they're wanting to use aircraft carrier nuclear power, but once developed it could find wind-powered civilian use.)

      The navy has to worry about delivery costs and operational advantages. Don't make the mistake of equating military feasibility with civilian cost-efficiency. After all, for civilian use a nuclear bomb would be a very costly and inefficient way of clearing a large chunk of land, whereas for the military it's quite effective.

    • Wind power has lots of advantages, but one major drawback - it is intermittent.

      We're talking about aircraft carriers here. I think the major disadvantage will be that masts and rigging will obstruct the flight deck to some extent.

  • Jet Fuel?

    Pfffft.

    I can turn large amounts of beer in to even larger amounts of urine, so what?

  • Produce the fuel on board? (Score:3, Insightful)

    by macraig ( 621737 ) <[moc.liamg] [ta] [giarc.a.kram]> on Thursday August 20, 2009 @03:48AM (#29130457)

    Perhaps they plan to build carriers with larger reactors that have greater output than the needs of the ship itself, so that the excess output can be used to power a small on-board jet fuel production plant? In that scenario, who cares if the energy required outweighs the work done by the resulting fuel?

  • More complicated than it looks (Score:3, Funny)

    by Grashnak ( 1003791 ) on Thursday August 20, 2009 @07:33AM (#29131533)
    Really? Turning sea water into jet fuel is more complicated than it looks? Cause from here it looks pretty freaking complicated.

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