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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

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

    by Brett Buck (811747) on Thursday August 20, 2009 @01:57AM (#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

  • Makes sense (Score:5, Insightful)

    by seifried (12921) on Thursday August 20, 2009 @01:58AM (#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.
  • Cost effective? (Score:1, Insightful)

    by NewsWatcher (450241) on Thursday August 20, 2009 @02:07AM (#29129691)

    For the life of me I can't see how this will be cost effective or environmentally friendly.
    I know sometime in the future there will be scarcity of oil, or peak oil (if we aren't there yet) but no-one seriously thinks that there will be so little fuel that a navy ship won't be supplied for many decades.
    Oil will become relatively more scarce through time, but at some point I think it will cease being used in cars and turbines, and used only for niche machinery and for making plastics. By the time there is no oil left for navy ships, I am betting another fuel source will have come along.
    Also, from TFA:
    "CO2's abundance, combined with concerns about global warming, make it an attractive potential feedstock, Dorner says. Although the gas forms only a small proportion of air - around 0.04 per cent - ocean water contains about 140 times that concentration, he says."
    Can someone smarter than me explain how it addresses concerns about global warming to get the highly CO2-concentrated sea water, convert it into fuel, that presumably is then sent via an exhaust stack into the air? Isn't it just like mining coal and sending it into the air, except this plan uses carbon in the oceans?

  • by MichaelSmith (789609) on Thursday August 20, 2009 @02:08AM (#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.

  • Naval waste (Score:3, Insightful)

    by harvey the nerd (582806) on Thursday August 20, 2009 @02:29AM (#29129789)
    Thermodynamically a huge waste.
  • by Anonymous Coward on Thursday August 20, 2009 @02:48AM (#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.

  • by lgw (121541) on Thursday August 20, 2009 @03:04AM (#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.

  • Re:Naval waste (Score:3, Insightful)

    by Daniel Dvorkin (106857) * on Thursday August 20, 2009 @03:06AM (#29129981) Homepage Journal

    Everything that every living thing does is thermodynamically a huge waste.

  • Re:Cost effective? (Score:5, Insightful)

    by serviscope_minor (664417) on Thursday August 20, 2009 @03:08AM (#29129999) Journal

    I mean, forget about all the CO2 produced when vast amounts of energy are expended to obtain, store, ship, and heat all that non-naturally occurring hydrogen - you don't need to know about THAT CO2

    Indeed. You don't need to know about it because it doesn't exist. The energy source is nuclear, not carbon based. If you didn't know that the US has nuclear powered ships, then you are clearly not a geek. Please hand in you card on the way out.

  • by Anonymous Coward on Thursday August 20, 2009 @03:11AM (#29130005)

    This isn't about making "gas" though. It's about making a kerosene-like jet fuel (also known as diesel). So not quite the same cars that most people drive.

  • Re:Cost effective? (Score:5, Insightful)

    by pluther (647209) <pluther@@@usa...net> on Thursday August 20, 2009 @03:30AM (#29130091) Homepage

    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?

  • Re:Closed Loop (Score:3, Insightful)

    by Rocketship Underpant (804162) on Thursday August 20, 2009 @03:40AM (#29130131)

    Not only that, you could use nuclear power to perform the operation, making it a carbon-neutral way of producing and using oil. Heck, if this ever ended up being an economical way to produce chemicals for plastics, it would actually sequester carbon.

  • by Rogerborg (306625) on Thursday August 20, 2009 @04:42AM (#29130425) Homepage

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

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

  • by macraig (621737) <mark.a.craig@g[ ]l.com ['mai' in gap]> on Thursday August 20, 2009 @04:48AM (#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?

  • Re:Or... (Score:2, Insightful)

    by Anonymous Coward on Thursday August 20, 2009 @04:50AM (#29130465)

    Actually, we CAN run planes on booze. It's just not very good for the fuel system, and it costs an arm and a leg.

    Not to mention the fact that it's a waste of perfectly good booze.

  • by Hognoxious (631665) on Thursday August 20, 2009 @04:52AM (#29130479) Homepage Journal
    Time for flying boats to make a comeback?
  • by mad flyer (589291) on Thursday August 20, 2009 @05:44AM (#29130721)

    Jet fuel is nearly the same as heating fuel. (depend on the jet...) And I like this smell of flight deck in winter when I turn the heater on...
    Heating fuel is the same as diesel fuel. (You can run your heater or your old benz)
    So yeah... jet fuel is not diesel... but it's damn close enough to be used as an emergency fuel in military helo even if the MTBF free fall make it a costly measure (somebody will have to quote tom clancy for me on this one)

  • Re:Makes sense (Score:3, Insightful)

    by Loligo (12021) on Thursday August 20, 2009 @05:58AM (#29130785) Homepage

    That is likely the reason they are considering this because if things
    continue to degrade with Israel and Iran

    Color me naive, but I imagine that things will go bad with EITHER Israel or Iran... one leads to the other. We'd have to REALLY fuck things up for things to go bad with both.

    Then again, I still don't fully understand what Obama's got planned...

  • by mpe (36238) on Thursday August 20, 2009 @06:03AM (#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.
  • Re:Hydrogen (Score:3, Insightful)

    by dltaylor (7510) on Thursday August 20, 2009 @06:04AM (#29130813)

    Hydrogen is a stupid fuel, except for fusion (and, maybe fuel cells).

    Storage is a royal pain, since hydrogen molecules are very small and simply wander off from containers, surrounding them with a highly flammable gas. If pressurized and cooled to liquid, they wander off less, but you have added costs of weight to the vehicle and compression/cooling to the production side.

    Per weight/volume, hydrogen generates relatively little power compared with hydrocarbon fuels . In general, the more carbon in the fuel molecules, the more energy available in combustion (you're not going to run high-performance aircraft on fuel cells). The C-C bonds are cheap to break compared to H-H bonds and C-O bonds provide decent return, so the net output is more. Diesel cars/trucks generate more useful power and better fuel efficiency than gasoline cars or hybrids. Similarly, there's a lot of energy in the long-chain molecules of kerosene/paraffin used as jet fuels.

  • by mpe (36238) on Thursday August 20, 2009 @06:43AM (#29130975)
    This isn't about making "gas" though. It's about making a kerosene-like jet fuel (also known as diesel). So not quite the same cars that most people drive.

    So is potentially useful for ships, aircraft (plenty of commercial airports located on or near to the sea), trucks, buses, construction, agriculture, etc, etc.
  • by Anonymous Coward on Thursday August 20, 2009 @06:52AM (#29131023)

    I was just having a fun jab with the first paragraph, but I do get the idea. The thing is, in the example you give where you have the two chemicals that mix, you're lugging around both chemicals, just like my example with the oxygen canister. With fuel based systems like internal combustion engines and fuel cells, you only have to carry around one of the chemicals. It's pretty hard to beat that chemically (at least for applications that aren't in space or underwater and therefore don't get oxygen for free), in fact, it may even be impossible.
    I think it's probably impossible chemically to beat the oxygen burning fuels for energy density in that case, however, it might be possible to beat them for _usable_ energy density. For example there are absolute physical limits on efficiency that internal combustion engines can achieve. Fuel cells also waste energy as heat. Maybe someone can find a method with two chemicals that combine and near 100% efficiency at converting their stored energy to electricity, or motion, or whatever, without all that waste heat.
    Or, maybe chemical won't be the way to go, maybe someone will figure out some way to store slow light laser pulses in a mirrored chamber for years or create some sort of superdense magnetic field storage, etc. Plus there's always nuclear, antimatter, etc. I remember reading something about micro-mechanical piezoelectric levers that generate electricity by capturing the impulse from alpha particles, for trickle charging tiny batteries for small devices like watches from a radioactive source. Sounds like a neat idea

  • Re:Or... (Score:4, Insightful)

    by Sj0 (472011) on Thursday August 20, 2009 @08:13AM (#29131375) Homepage Journal

    I did always find it odd that people who didn't have sex were judged based on their sexual preference.

  • Re:Makes sense (Score:3, Insightful)

    by SDF-7 (556604) on Thursday August 20, 2009 @09:16AM (#29131899)

    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 projected peak draws. This may fit just fine since you'd presumably only be making fuel in the "off" times (i.e. when you aren't in direct combat operations, steaming at cruise instead of flank, etc.) If this gets worked out -- I'd presume enough tanks on board to handle N days worth of expected worst-case flight ops and the plant keeps that tank topped off as needed, not a "must use the plant to launch planes" only model).

  • by gtall (79522) on Thursday August 20, 2009 @09:48AM (#29132229)

    Incidentally, the U.S. Military has a standing directive to reduce its enviro-footprint wherever possible.

  • by Chris Burke (6130) on Thursday August 20, 2009 @03:16PM (#29137107) Homepage

    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 the future and using the fleet of today to argue for continuing to use fuels. That doesn't make sense.

    Tell you what, you root for seawater-into-fuel processing to grow enough to supply all the hydrocarbon needs of our fleet and I'll root for our fleet to switch to electric and we'll see who wins. Hey maybe we'll get the best of both worlds, and most cars will be electric, and those that aren't will be able to use carbon-neutral artificial gasoline.

    on top of a creaking already over-strained electrical grid.

    Lol, right. So we don't have the electrical infrastructure for electric vehicles, but we do have it for electrically-generated-liquid-fuel, even though that is going to take a lot more electricity since the conversion of that fuel source into kinetic energy is so much less efficient than an electric motor. That makes tons of sense.

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