US Navy Tries To Turn Seawater Into Jet Fuel

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.'"

Comments

Re:Cost effective?

[Dunbal]

oceans absorb CO2

CO2 + H20 H2CO3

H2CO3 ==> HC03- + H+ with a pKa of 3.6

This means that we will eventually turn the oceans into Coca Cola. Not too good for the flora and fauna, I can imagine. There's a practical limit to the CO2 that the oceans can absorb.

Of course if we could create some sort of genetically engineered algae that happened to produce carbonic anhydrase, you'd be able to degas huge amounts of ocean water just by pouring it into your algae tank...

Re:Trying to avoid Methane?

[afidel]

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 =)

60% of a nuclear reactor is "waste" heat

[Colin Smith]

So it may actually be more efficient thermodynamically.

Re:Or...

[WED Fan]

Nuclear planes? This was tried way back when. They never really got to a full test but their biggest problem was once you actually got a working reactor on an aircraft, what did you do when they crashed? Not a good idea. The few bombs we've lost over the years, most no in populated areas, have been enough of a public relations disaster.