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The Military Transportation Science Technology

Navy Creates Fuel From Seawater 256

Posted by Soulskill
from the no-blood-for-seawater dept.
New submitter lashicd sends news that the U.S. Naval Research Laboratory has announced a successful proof-of-concept demonstration of converting seawater to liquid hydrocarbon fuel. They used seawater to provide fuel for a small replica plan running a two-stroke internal combustion engine. "Using an innovative and proprietary NRL electrolytic cation exchange module (E-CEM), both dissolved and bound CO2 are removed from seawater at 92 percent efficiency by re-equilibrating carbonate and bicarbonate to CO2 and simultaneously producing H2. The gases are then converted to liquid hydrocarbons by a metal catalyst in a reactor system. ... NRL has made significant advances in the development of a gas-to-liquids (GTL) synthesis process to convert CO2 and H2 from seawater to a fuel-like fraction of C9-C16 molecules. In the first patented step, an iron-based catalyst has been developed that can achieve CO2 conversion levels up to 60 percent and decrease unwanted methane production in favor of longer-chain unsaturated hydrocarbons (olefins). These value-added hydrocarbons from this process serve as building blocks for the production of industrial chemicals and designer fuels."
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Navy Creates Fuel From Seawater

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  • by Anonymous Coward on Wednesday April 09, 2014 @02:39AM (#46702377)

    This looks like you get both worlds: nuclear and solar fuel.

    You need a nuclear plant to power the converter, and you use the sea as a solar panel to get the H2 in it.

    The only nice point would be: CO2 sink. The world has too much CO2, that could consume a few part of it to make back long hydrocarbon.

    The new plane are to be electric... the new electricity storage is to be done in fuel. Forget NiCd and other Nickel based product.

  • Re:They do. (Score:5, Interesting)

    by Demonantis (1340557) on Wednesday April 09, 2014 @03:55AM (#46702587)
    Aircraft carriers are like a space limited island villages with a nuclear power plant. The power goes to more than just propulsion so its built into the design plans. Desalination, waste water treatment, and machine shops for sure. There is probably a tiny factory on board for as many products as they can have one for. Manufacturing on demand is highly desirable. Not only is resupply is a massive pain, but it takes up valuable storage space.
  • by Dave Emami (237460) on Wednesday April 09, 2014 @04:16AM (#46702661) Homepage
    What I'm wondering is, can they modify this process to produce edible hydrocarbons? Probably not something you'd enjoy eating, but the primary limitation on a nuclear submarine's endurance is the food supply for the crew.
  • That depends (Score:2, Interesting)

    by DeathToBill (601486) on Wednesday April 09, 2014 @05:11AM (#46702789) Journal

    Depends on where in the supply chain that $3/gal is. $3/gal supplied to the US Navy is probably more like $7 or $8 at the pump for putting in your car - not so viable.

  • Not trivial at all (Score:5, Interesting)

    by sjbe (173966) on Wednesday April 09, 2014 @08:34AM (#46703579)

    At sea refueling is trivially easy, all you need is a ship that can carry a lot of fuel, a pump, and a hose.

    "Trivially easy"? I think the Navy would disagree strongly with you on that. There are a huge number of non-trivial logistics issues. You have the expense of maintaining a second ship. You have to have that ship transport the fuel to an arbitrary location on the globe. You have to keep the fuel supply safe and ensure that the fuel tender isn't tracked back to the ship it is refueling. You have a ship with a large amount of potentially explosive fuel on board with all the attendant safety hazards that causes. It means your ships are limited in where they can go and how long by their fuel supplies rather than mission parameters.

    The fact that they're fairly good at doing it doesn't mean it is something they find easy or useful. Cut of a military's fuel supply and they are effectively helpless. Fuel logistics are a HUGE and expensive problem for the military. It supposedly costs something like $16 to transport $1 worth of fuel. Also bear in mind that a lot of fuel comes from pretty volatile locations that we are likely to engage in hostile action with. There is a reason our military is putting a LOT of money into alternative fuel research. It's a huge cost and a huge tactical/strategic problem for them.

    And realistically, when is a carrier or other ship likely to be far from supply lines?

    Middle of the Pacific perhaps? Or any other ocean? Or when near hostiles? You don't really want to be refueling anywhere close to the people you are fighting if you can avoid it.

  • Re:They do. (Score:2, Interesting)

    by Anonymous Coward on Wednesday April 09, 2014 @09:04AM (#46703731)

    Thorium fuel is highly available, and the fuel is a natural neutron-absorber, so the natural state of the reactor should you need to SCRAM is to shut down the neutron chain reaction and push the molten salt fuel out of the reactor core, where it is cooled. And the fuel byproduct is only dangerously radioactive for a couple hundred years, and after that, it is safer to handle than Uranium ore. And it can't be weaponized.

    So, do we have a requisite $40 billion to earmark to this program and get it up and running? I'm sure we could have pocket plants up and down the seaboard, churning out electricity and converting seawater to long chain hydrocarbons for use in industry and as a stored fuel source. I would predict energy independence in under a decade if we were to fund this like another Manhattan Project and recruit the best minds from various industries and share the results with the rest of the world.

    Right now, this seems more promising than investing more money into plants that use Uranium-cycle fuel. These plants have proven to be too vulnerable to human error and natural disaster, and the expensive long-term storage of spent fuel that has to be kept away for several thousand years. And this spent fuel can very easily become a weapon in the wrong hands.

  • Energy inputs (Score:4, Interesting)

    by FishTankX (1539069) on Wednesday April 09, 2014 @10:21AM (#46704437)

    Assuming that this process is 10% efficent let's take a look at the numbers.

    Let's say you can dedicate half of the 1.1GWT (thermal) of the nimitz to aviation fuel production, if you're holding off coast.

    And let's assume conservativley that the process is 20% efficent.

    Diesel (pretty close to JP1) has an energy density of 35 MJ/L. This means at 20% efficency you'll be needing 175mj to create 1 liter of JP1.

    At 1/2 1GWT you're looking at about 3 liters of fuel per second, or about 172,000 liters a day, or about 40,000 gallons. The nimitz has about 3 million gallons of fuel capacity so the refueling time of the entire tank from 0 would be around 2 months. According to this article here

    http://large.stanford.edu/cour... [stanford.edu] (Also about marine jet fuel fabrication, provides some of the hard numbers) 3 million gallons is enough to refuel the onboard fleet about 20 times. So onboard fuel production would provide 1/3 of a full tank of gas for each aircraft onboard per day. Not terribly good, or bad.

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