The US Navy has apparently worked out how to take CO2 & hydrogen from seawater and turn it into a useable fuel for about 3-6 bucks/gallon.
Should we be excited?
I doubt it. There is no difficulty getting fuel from seawater – you can, for example, simply electrolyze the water and produce all the H2 and O2 you want. The problem is cost. It would consume way more energy to electrolyze water, for example, than you would get back by burning it.
The same appears true here, although details are scant. The vague quote in the article is that jet fuel would cost $3-$6 per gallon (which I’m sure in addition to being a WAG is a wildly optomistic WAG, involving all kinds of hopeful assumptions about economies of scale). That’s something like twice to four times the current cost. Only the Navy would be interested in this kind of thing, because they don’t mind paying way more for fuel in order to have it more conveniently available. Their priorities are speed and convenience, with cost far down the list. That’s how we get $500 military hammers.
One hates to put one’s faith in press releases, eh?
Should we be excited? It depends. If you’re the Navy and you want to some day not have to maintain a tanker fleet, then yes.
If you’re expecting this to solve world energy problems, no. This solves* a problem fairly specific to the use case for the Navy and not a general problem.
It takes more energy to produce the fuel than is in the fuel that is actually produced. That’s why it couldn’t solve global energy needs. But it can often, locally, be worthwhile to go down such a route. The reason is, if you’re on a big Navy ship maybe with a nuclear reactor powering it, it might make sense to just be able to produce your own jet fuel at sea instead of going to the expense of staffing, maintaining and etc an entire fleet of fuel tankers that follow you around. Not to mention the cost of buying those tankers and the cost of fueling the tankers themselves.
It’s not net energy positive, but it could actually be cheaper than sailing around the ocean with a large fleet of ships bobbing along after you full of fuel, only there for the purposes of refueling.
Additionally it’s a ready way to make energy dense fuel, which if you need energy dense fuel because that’s what your warships and Naval planes are designed to use do you really care that you’re using 1.5x of energy to produce 0.85x of liquid fuel? Maybe, maybe not. It depends on the specifics, but in theory I could imagine a scenario where you prefer that inefficient conversion versus the current expense of the tanker fleet. Plus, it theoretically makes the Navy able to run its planes and I guess its fuel powered warships independent of petroleum access (again, in theory, as this process would have to be scaled up massively.)
*By solves I mean this is a small scale demonstration that demonstrates some minimal proof of feasibility for technology that could many many years down the road maybe solve this problem for the Navy.
I believe most experts feel our solution to world energy problems will involve a rich mix of technologies, not a panacea fusion tech or something.
Right, but this isn’t so much an energy problem being solved so much as it is a fuel problem. Our Naval ships and planes (aside from nuclear powered ships) are fueled by petroleum based fuels and there are real concerns with say, making a fighter jet that runs on solar power or something.
It’s sort of like Germany in WWII, they needed fuel to run their tanks and trucks, but what they had was coal. Those vehicles couldn’t be ran directly as coal fired, and Allied efforts against German shipping made petroleum fuels difficult to keep in good supply in Germany. So, they converted coal to fuel, a process that is an energy loser, but when coal is what you have it makes sense.
Ships at sea are in a similar boat so to speak, it’s expensive and logistically difficult to maintain a whole fleet of fuel tankers just to keep a fleet of warships and its planes on the open seas. The Navy has basically unlimited access to sea water, though, so maybe some day this technology would allow fleets to produce all their own fuel and not need the tanker ships.
That’s the fanciful, far off scenario. The reality is I suspect the energy constraints will always make it so you need some tanker fleet infrastructure. And of course the process needs external power, too, I’d think most likely a nuclear reactor.
This could, in principle, someday become practical for the private sector, depending on how other technologies progress. I can envision the development of a cheap, abundant source of energy that only really works in fixed power plants: Maybe something exotic like fusion, maybe something as mundane as really efficient windmills, the details don’t matter. But to use that energy to propel a vehicle, you probably need to store it somehow, especially for aircraft. And given that we live in an oxygen-heavy atmosphere anyway, hydrocarbons are a really, really good way to store energy: The energy density is much higher than any other current tech, and it’s very safe against accidents.
It’s no guarantee that this will happen, of course. Maybe batteries or capacitors will advance to the point where they can do an even better job. Maybe we’ll switch to catenary wires or third rails or the equivalent to power our land vehicles, with high-speed trains taking up most of the airplane niche, and what natural fossil fuels we have will be adequate for the few planes remaining. Maybe we’ll focus on telecommuting and such to the point where we mostly won’t even need vehicles. But it certainly could happen.
The article doesn’t explain where the carbon in the co2 comes from. Doesn’t make sense.
CO2 = 2 Oxygen atoms bound with one carbon atom.
Edit: Sorry, if you were asking where the CO2 itself came from (and not where the carbon came from), there is abundant CO2 naturally in the seas.
Supposedly it will free ships from dependency on tankers; but that wouldn’t help much if the process is dependent on an external energy source like a nuclear-powered vessel devoted to fuel production, that ships would have to rendezvous with. And I can’t think of any chemical reaction (like calcium carbide plus water yields acetylene) that wouldn’t be less energy-dense then just carrying the fuel. I keep just finding clones of the same basic article, with no explanation whatsoever of just how it works. If a known admiral’s name wasn’t associated with this, I’d think it was a hoax.
(bolding mine)
Actually, this site says the price of jet fuel is currently about $6/gallon, give or take depending on location.
This site shows prices from $5.37 to $6.28/gallon.
So it looks like the cost is about the same or less than jet fuel costs right now… and you wouldn’t have to carry as much fuel, so displacement for water craft could maybe be less, which would increase efficiency, etc.
I saw it on my Facebook newsfeed, googled the Admiral’s name and traced it back to Defense News in hopes I was avoiding libro-glurg.
Those are retail prices, what you’d pay if you were filling up your private plane at an airport, and include federal and local taxes, markup by the retailer, etc. The USN would pay much less due to tax exemptions and significant economies of scale.
From this article it describes it as a patented process. So I would assume if we can find out which patent it is, it would have to detail the process.
That article explains it briefly as:
There is abundant dissolved co2 but the concentration is low. There is more dissolved nitrogen. Why would the researchers be interested in isolating a highly oxidised for of carbon and why would the article even mention something that is present in such small concentrations?
That explains the article. Carbonates provide the carbon for gas to liquid synthesis. Still sounds energy intensive and more like an energy storage system.
Well, we can’t forever have net positive energy sources, so looking for “more or less affordable” energy is okay isn’t it? Charging my multimedia phone is a net drain, but it’s worth the while.
Yeah, I think I had already made it clear–the intent for this is to produce an energy dense fuel. It isn’t to produce net energy. Fighter jets for example only run on jet fuel, the Navy has made the reckoning that they might want the ability to produce jet fuel from sea water because it frees them from dependence on a non-renewable resource, but they aren’t saying it’s a mechanism for generating energy, only converting one type of energy into a more energy dense form suitable for powering jet planes. Energy is lost in this process so it is not net energy positive.
I still would like to know how they hell they’re getting “H2” from seawater, other than nuclear-powered hydrolysis; non-nuclear ships would still be dependent on rendezvous and fuel transfer which the article implied this would eliminate. Nuclear carriers being able to make their own jets’ fuel on demand would be a big step, but I don’t see how this helps the rest of the Navy.
ETA: Unless they meant that the carrier would supply all the fuel needs for it’s task group, which makes a little more sense.
It seems to me that if the Navy ever gets a viable rail gun that would mesh well with this technology. A nuclear-powered cruiser with a rail gun and the ability to produce fuel for smaller escorts would seem to be a good match.