

Scale Model WWII Craft Takes Flight With Fuel From the Sea Concept - omegaworks
http://www.nrl.navy.mil/media/news-releases/2014/scale-model-wwii-craft-takes-flight-with-fuel-from-the-sea-concept

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TrainedMonkey
At best this technology would allow capital ships with nuclear reactors
(mostly carriers) to produce hydrocarbon fuel in order to resupply nearby
craft. In theory this would help to optimize naval supply chain.

~~~
bpodgursky
I think that's simplistic. It lets any energy source with access to seawater
store energy in a very energy-dense medium, eg gasoline. Oceanic wind-
turbines, solar panels, nuclear generators on the ocean, etc. Certainly more
useful short-term for the navy, but could definitely be extended to civilian
uses.

~~~
aaron695
Yes, but given the huge demand for energy everywhere there is absolutely no
point wasting so much energy converting it except in locations where/when
transporting a energy-dense medium to is difficult but highly valuable.

IE The middle of the ocean during a war.

~~~
dredmorbius
The cost for this energy is $3-$6/gallon according to the US Navy's estimate.
I get about $9/gallon if you include the costs of solar power provisioning. Or
$126 - $378/bbl.

That's not cheap, but it's a damned sight better than pretty much any biofuel
alternative, which runs about $1000/bbl.

And fuel is essential for transportation. Some transport can be liberated --
you can run passenger cars on batteries (for a price). Within cities, buses
and even delivery vehicles can be electrified (possibly with on-board
batteries for short off-grid excursions). Rail absolutely can be electrified.

But a lot of uses cannot be.

It's difficult to run power cords across oceans (though you _might_ be able to
electrify some barge and river traffic). Especially if you want to tap into
them at sea. An electrified marine cargo business isn't an option. Your
primary alternatives are sail power, biofuel (including possibly pelletized
wood ships, an existing proposal), or electrically-generated synfuels as here.

Airplanes handle electric cords even worse than boats do. There are numerous
airline industry initiatives looking at biofuels, but Boeing's "biggest
breakthrough there is" bet really doesn't pan out. Unless you want to cover
_all_ of Oklahoma and Kansas, as well as parts of Louisiana, Texas, New
Mexico, Colorado, Nebraska, and Missouri, _just_ to supply fuel to the
aviation industry.

Worldwide, shipping and aviation account for about 5% each of total petroleum
consumption.

Or you could create the fuel. Yes, shipping prices, airfares, and air cargo
rates would increase. But you'd still have them.

~~~
anigbrowl
And while that's expensive by the standards of fossil fuel extraction (with
oil at an unusually low price of ~$75/bbl right now), the cost of solar
generation keeps falling and seemingly has further to fall, whereas the costs
of fossil fuel extraction seem set to keep rising - both because of the
increasing difficulties of access and because of increasing pressure to
account for externalities, whether at the point of production (like wastewater
injection) or consumption (CO2 and soot pollution). We should probably be
looking at $126/bbl (at $3/gal) for fossil fuel so as to include the refining
costs that would be obviated by this technology (and which have unaccounted-
for externalities of their own).

I don't see what's not to like here. You could even use relatively inefficient
solar harvester arrays anchored offshore to do most of the processing, and in
the event of a spill it would still be substantially cleaner and easier to
manage than crude.

~~~
dredmorbius
I'm generally pessimistic about the future. This is among the most interesting
and positive things I've run across in years.

There are still limitations, as I noted. Solar costs are falling, but if you
look at _total installed system_ costs remain high. EROEI and other metrics of
net positive energy are perilously close to minimums necessary to sustain
civilization.

I'm not a fan of marine-based installations just based on weathering and
corrosion. But a number of industrially-large plants would work. For the U.S.,
a single facility 4.5 km x 4.5 km x 10 m high would suffice based on USNRL's
scaling factors. Split that among a number of regional facilities and you've
got distributed capacity at a large industrial scale.

It's the solar collection that's the big and pricey part of this.

~~~
anigbrowl
Thanks for your very interesting analysis here and above - I will certainly
dig through your Reddit posts on the subject as I want to learn more about
where the manufacturing barriers would be and what sort of private
partnerships the Navy would enter into over the projected 7-10 year deployment
timeframe, not least because I'm struck by the fact that the basic technology
must be unencumbered by patents to the extent that it originates with the
government.

While agreeing that solar collection is no slamdunk (see for example this
story about the SoCal Ivanpah plant running at only half the hoped-for
capacity at present: [http://www.mercurynews.com/business/ci_26954832/huge-
mojave-...](http://www.mercurynews.com/business/ci_26954832/huge-mojave-solar-
plant-lags-energy-production)) I'm personally OK with nuclear, geothermal and
hydroelectric dams as potential power sources notwithstanding their own
externalities.

~~~
dredmorbius
The part that's likely _not_ to be unencumbered is the CO2 extraction itself.
But otherwise, yes, much of this is public-domain tech.

I'm on the fence regarding nuclear for at least two main reasons: safety
(particularly the hard-to-quantify-of-guarantee long-term safety), and fuel
availability. The picture on both strikes me as less than clear. Near term,
perhaps useful as a bridge fuel.

Geothermal is actually pretty awesome, but much more profoundly limited than
most people suspect (tide and wave power are also overestimated -- the San
Francisco Bay, for example, represents less total tidal power than the bay
region uses in electricity, and only a small fraction of that potential could
be extracted). Enhanced geothermal (basically, injection wells) have proven
expensive and low-benefit, see Australia's Habanero project and its
challenges.

Hot, wet-field geo though is proven, and a high-yield resource in Iceland,
Japan, the Philippines, Kenya, New Zealand, the US, and a few other regions.
In developing regions (particularly Kenya) it could dramatically increase
total electrical generation capacity.

Hydro is largely built out and has environmental issues, though it also works
quite well.

It's a sticky problem.

------
dredmorbius
I've been looking into the research on this process for a few months. In a
world with a lot of bleak news on energy fronts, it offers some promise -- not
of "free energy" (it isn't), but of a sustainable, abundant, predictable,
carbon-neutral liquid fuel provisioning option.

First: liquid hydrocarbon fuels are hugely useful for a number of
characteristics.

They're very energy dense, by both weight _and_ volume. They've over ten times
the energy storage density of batteries, and while they have lower energy
density by unit weight than hydrogen, have over seven times the density by
_volume_ with vastly fewer handling constraints. They're easily handled (no
high pressures, low temperatures, corrosion, embrittlement, or other issues).
They're generally really safe -- many liquid hydrocarbons won't explode unless
specifically induced to do so. They're a drop-in replacement for existing
fossil fuels. They could be blended with these, and can utilize the same
processing, transport, and utilization infrastructure. Engines would not have
to be modified. At the same time, for those who see efficiencies in electric
drives, they're amenable to hybrid-drive technologies. And we've got well over
a century of expertise in utilizing them.

For transportation, liquid hydrocarbons are very hard to beat, and for certain
modes, all but essential, especially heavy land cargo, marine shipping, and
air travel.

The research that the US Naval Research Lab is conducting is based on over 50
years of work on the concept, with the first studies undertaken by nuclear
physicist Meyer Steinberg at the Brookhaven National Laboratory in 1964.
Steinberg continued his research through the 1990s, with further work at
M.I.T. under Michael J. Driscoll and more recently as USNRL (who peculiarly
fail to cite the earlier research -- it's rather like an evolutionary
biologist failing to credit Darwin). Steinberg's work generally considered
nuclear power as the electricity source, though any generating option could be
substituted. More recent research considers nuclear, solar, and OTEC, an ocean
thermal power system.

The basic concept was suggested by M. King Hubbert, the petroleum geologist
who predicted peak oil in the 1950s, in a 1962 report (though he suggested
mining carbon from limestone).

In terms of process, there are two very-well understood processes operating at
industrial scale presently, hydrogen electrolysis and Fischer Tropsch
synthesis. The third stage is where most research is focused: on finding means
to sequester carbon from seawater. A small fraction is present as dissolved
CO2, but most (about 96%) is in the form of dissolved carbonate and
bicarbonate.

Since carbon is being drawn from the biosphere (seawater), it's overall carbon
neutral, though it might tend to bias balance slightly toward the atmosphere
as compared to the oceans. If run in excess of human energy needs (a very
expensive proposition), it could sequester additional carbon from the
atmosphere.

The primary energy cost is in the electrolysis, which returns hydrogen with
about 60% of the energy capacity as the input electricity -- so your
conversion costs you energy. Fischer Tropsch processing is exothermic (more
energy is released than consumed). Energy usage of the CO2 separation phase is
comparatively low, much of it is in the water handling -- you've got to move a
_lot_ of seawater to get the carbon necessary. I suspect overall efficiency
will be roughly 50%.

Though the Navy research is looking at this for their own purposes, it could
just as well be used for civilian purposes. The 100,000 gallon/day capacity
seen for a carrier task force would be roughly appropriate for a city of
100,000. My own cost estimates, including solar power provisioning, are higher
than the Navy's, about $9/gallon. But that would be a stable price going
forward -- with a renewable liquid fuels source, there are no oil embargoes,
supply shocks, or imports.

At a national scale for the United States, supplying 20 million barrels/day,
you'd require 2TW of power -- a solar collection region about 180 miles on a
side. That's quite large, but as compared with biofuel-based alternatives,
downright reasonable -- most plant-based fuel proposals if scaled out would
require a sizeable fraction, or several multiples, of total US land area to
provide an equivalent of present petroleum usage.

On the "bad news" front: the fact that research has been conducted in this
area for 50 years _without_ significant implementation suggests that there may
be engineering or other challenges which are frustrating broader application.
Or it could be that fossil fuel prices have simply been too low to allow
larger-scale demonstrations.

I've explored a few other aspects of this in a series of reddit posts covering
the USNRL's work and other historical background.

Search on "fischer tropsch":
[http://www.reddit.com/r/dredmorbius/search?q=fischer+tropsch...](http://www.reddit.com/r/dredmorbius/search?q=fischer+tropsch&restrict_sr=on&sort=relevance&t=all)

USNRL research and papers:
[http://www.reddit.com/r/dredmorbius/comments/22k71x/us_navy_...](http://www.reddit.com/r/dredmorbius/comments/22k71x/us_navy_electricitytofuel_synthesis_papers_and/)

BNL/MIT history and papers:
[http://www.reddit.com/r/dredmorbius/comments/28nqoz/electric...](http://www.reddit.com/r/dredmorbius/comments/28nqoz/electrical_fuel_synthesis_from_seawater_older/)

M. King Hubbert connection:
[http://www.reddit.com/r/dredmorbius/comments/298a4l/seawater...](http://www.reddit.com/r/dredmorbius/comments/298a4l/seawater_fischertropsch_fuel_synthesis_the_m_king/)

And for comparison, limitations on biofuel potential:

[http://www.reddit.com/r/dredmorbius/comments/28k1w5/prospect...](http://www.reddit.com/r/dredmorbius/comments/28k1w5/prospects_for_biofuels_limited_additional/)

[http://www.reddit.com/r/dredmorbius/comments/2cvap7/the_intr...](http://www.reddit.com/r/dredmorbius/comments/2cvap7/the_intractable_problem_of_biomass_for_fuels_is/)

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jkaunisv1
I guess the output of the fuel after use is still greenhouse gas, but would
this reduce net CO2 emissions?

~~~
xxgreg
The carbon in the fuel comes from CO2 which is captured out of sea water.

The problem with fossil fuels is that they transfer old carbon which used to
be stored underground into the atmosphere.

This process only uses carbon that is already part of the active carbon cycle,
so it is carbon neutral as long as the electricity source is.

~~~
jkaunisv1
Yeah, that's what I was thinking. It's not eliminating carbon in the
atmosphere, but it's avoiding adding more from fossils.

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magd
It can't get worse.

