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Generating hydrogen from seawater to power boats

By | October 26, 2010, 4:00 AM PDT

Scientists have been exploring how to best produce hydrogen from water for use as a fuel, without using electricity to do so. At Purdue University, they are looking to the sea. The chemical engineers have discovered a way to take the hydrogen from seawater using bulk aluminum and a metal alloy.

Their work stems from previous research enlisting aluminum-based alloys to generate hydrogen from freshwater. Freshwater, however, is in short supply (not that we should go haywire with seawater). But the researchers are thinking big. In addition to storing energy from wind and solar farms, they hope their process might eventually power seafaring ships, even tankers, cruise ships, and the sort.

Purdue’s Jerry Woodall in a statement:

The method makes it unnecessary to store or transport hydrogen, two major challenges in using hydrogen for ships and vehicles. We generate the hydrogen on demand, as you need it. It also eliminates the need to store freshwater when used for marine applications.

Should the method prove seaworthy at that scale, the end products of hydrogen fuel combustion are water vapor and heat. The shipping industry emitted 847 million tons of carbon dioxide in 2007. The amount was almost 3 percent of human-made CO2 emissions that year, according to the International Maritime Organization.

Their hydrogen-releasing formula, which is patent-pending, is 90 percent bulk aluminum and 10 percent liquid metal alloy, consisting of gallium, indium and tin. The gallium dissolves the aluminum, allowing it to react with the oxygen in the seawater. The hydrogen atoms break free from the water molecule. The end product is aluminum hydroxide, which can be recycled back into aluminum.

Despite their seawater hydrogen recipe calling for indium, which has supply issues, the researchers contend it could be cost-competitive.

Related on SmartPlanet:

Images: Flickr/AA <α>photography.tw and Purdue University photo/Mark Simons

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Melissa Mahony

About Melissa Mahony

Melissa Mahony was a contributing editor for SmartPlanet from 2010 to 2011.

Melissa Mahony

Melissa Mahony

Contributing Editor, Energy

Melissa Mahony has written for Scientific American Mind, Audubon Magazine, Plenty Magazine and LiveScience. Formerly, she was an editor at Wildlife Conservation magazine. She holds degrees from Boston College and New York University's Science, Health, and Environmental Reporting Program. She is based in New York.

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Melissa Mahony

Melissa Mahony

Melissa does not have financial holdings that would influence how or what she covers. She currently works for the Wildlife Conservation Society as an editor. Should Melissa cover a topic in which the WCS is involved, she will disclose this fact in her writing.

She writes for SmartPlanet and is not an employee of CBS.

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+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
This explains why making aluminum requires so much energy. You're basically making a fully-charged battery. I have to wonder, though, if you get enough energy out of aluminum to make carrying all that weight around practicable. It's probably another reason why this is best suited for ships.

Of course, you still have the original problem of where are you going to get the energy in the first place. "Wind and solar farms" are the standard answer, but the economics are still far from proven -- especially in an application such as this.
Posted by zackers
26th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
A long term problem that might develop could consist of an industrial extraction process of Hydrogen that disrupts the natural equilibrium of sea-water chemical content, hence, contributing to Hydrogen-Oxygen-Deuterium-Salt disequilibrium affecting evaporation rates conducive to rain production, which could then have a negative impact upon weather systems. In addition, by-products might not interface with the environment in a reactive way that sustains extant element stock in the atmosphere and hydrosphere for ecological efficiency. In other words, Entropy dictates that for every action that ultimately amounts to resource depletion (e.g., Hydrogen extraction) there is a reaction (e.g., non-sustainable unrecyclable waste). The Earth is a closed system in which all resources are finite via predetermined chemo-physical processes bounded by the laws of Thermodynamics. In a bounded state of finite resources and elements, Entropy is inescapable. Thus, in the same way that petrochemicals will eventually be exhausted, ocean waters will be destructively impacted in their elemental composition, chemical resources and ecological processes.
Posted by lion of paradise
26th Oct 2010
+1 Vote
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RE: Generating hydrogen from seawater to power boats
Of course, there are two questions not addressed in this article:

1) How much hydrogen can be produced by how much aluminum ? Only then can any analysis be made about whether the weight issues of the Aluminum. Why do I suspect that there isn't anywhere near the energy density necessary?
2) How much energy is needed restore the aluminum hydroxide. That isn't going to be free.

Why doesn't the article recognize that the energy in creating the aluminum and then restoring the aluminum from the hydroxide back to elemental aluminum are the energy inputs necessary in this process. Instead, she perpetuates the myth that there is free hydrogen in the water waiting to be filtered out that will solve all our energy needs. The author should be ashamed of herself for perpetuating "anti-science." This is simply bad reporting.
Posted by Steve70638
26th Oct 2010
+1 Vote
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RE: Generating hydrogen from seawater to power boats
Why can't they just use solar and wind power to generate the electricity to liberate the hydrogen from the sea water?
Posted by stefanis
26th Oct 2010
+1 Vote
+ -
Conservation of ENERGY
I'm with Steve 70638: "The author should be ashamed of herself for perpetuating "anti-science." This is simply bad reporting."

So, you want to liberate some hydrogen from its oxygen, recombine it with oxygen in the air to move a ship, then ship the sequestered oxygen (with the aluminum it's attached to) back to the factory for reprocessing.

It's a shell game. You're just moving around the source of energy production. There's no "clean" anywhere in this equation unless the reprocessing plant (the ultimate source of the energy in the whole scheme) is run on geothermal, wind, or hydroelectric.
Posted by bromikl
26th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
The simplest and cheapest way to make a lot of hydrogen, was invented in the 40's, by a man from Bolivia. Check this article : http://www.rexresearch.com/pacheco/pacheco.htm
Posted by aleader@...
26th Oct 2010
+1 Vote
+ -
The old free lunch trick
Would-be green energy fans need to get it through their heads that breaking the hydrogen-oxygen bond to "produce hydrogen" from water CANNOT consume less energy than will be released when the bond is restored by burning the hydrogen. It's the same hydrogen-oxygen bond, whichever way you are conducting the reaction. You want enough energy to push an ocean-going freighter across the Atlantic, then somewhere you must put in enough energy to push an ocean-going freighter across the Atlantic. Put it in at an aluminum plant if you like, but what you won't get is "free clean energy."
Posted by Robert Hahn
26th Oct 2010
+1 Vote
+ -
A tiny correction
The earth is not a closed system. Every day we get loads of energy
from the sun. It is absorbed by the earth, plants, seas, everything. A
lot of this energy escapes to space again, but the existense of oil
proves that we get a little more energy than what has escaped.
Apart from this the laws of thermodynamics apply.
Posted by Dukhalion
26th Oct 2010
+1 Vote
+ -
Generating hydrogen to power SHIPS also
Dear Melissa Mahony,
To a reporter, words are strong, because they convey not only ideas, but convey how knowledgeable the speaker is on a subject. People that use the word 'boat' with a picture of an oil tanker or freighter do not know much. 'Ship' is an ocean-going vessel, while 'boats' are made for short voyages along the coast, for lakes and rivers. Ships can carry boats. Unfortunately, when one says that seawater can be used to power 'boats', one implies that ships are left out.

I enjoy your articles. Keep writing and I'll keep reading!
Posted by markpowers80@...
26th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
There is no bad reporting or anti-science here from Ms. Mahony, just poor reading comprehension from people posting critical reactions. The problem is to store energy generated elsewhere - such as wind farms & solar powerplants - in a manner that can be used by boats & ships. It's not about generating energy, it's about storing it within the limitations of certain vehicles.
The limitations of battery technology make storing the energy as electricity impractical. If you could store enough electricity, you wouldn't need to extract hydrogen from seawater, you'd use it directly in electric motors to propel the boat or ship.
Posted by hoodedswan
26th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
Boys and girls, please stop throttling the author. She is reporting on a technical subject and not representing herself as an engineer. The hydrogen generating properties of Aluminum alloys in the presence of a Galium catalyst have been known since the early 1900's, when they were first used in Germany. More recent research has been undertaken at Duke University. There are some materials science challenges being explored (probably what can be patented), since the principles behind generating hydrogen using an aluminum alloy have been around for over 100 years and cannot be patented. Restoring the alloy to a reusable form simply requires heating (to the best of my recollection). Perhaps "simply" is an oversimplification. I'm not particularly well versed in all of the details. My nephew (a Phd Engineer working on stuff for the government he can't tell me about) clued me in to this aluminum process a few years ago. The weight of the aluminum allow is not a problem, nor is recycling the materials, especially on a ship. The whole point of generating hydrogen (beyond using it on demand) is the ability to store all of that potential energy (not in a tank, but in a special ceramic like material that releases it upon heating), which would be far more efficient than any battery technology, real or imagined. As far as using the hydrogen to power the boat, I'm pretty sure that the intent is to use hydrogen cells as a power plant for one or more electric motors. It's not likely that anybody would want to use it in an internal combustion engine (although BMW produces a car that can use it this way) on a ship, since it would make sense to have one or more back-up generators working with other technology (diesal, etc), when the hydrogen power plant is on the fritz. That way, it would not matter how the electricity was sourced, since the power to turn the screws would always come from electric motors, which are far more reliable than the Rube Goldberg technology we use in our cars.
Posted by PSFTGURU@...
26th Oct 2010
+1 Vote
+ -
Bah! Humbug! A pox on Hydrogen snake-oil salesmen!
And why is it that these Hydrogen snake-oil salesmen always seem to come out of universities? Particularly American ones.
Government grants.
Private industry grants.
Tenure (or promises thereof)
And... making it out of ALUMINUM now! One of the most energy-intensive process is needed just to MAKE aluminum! And now some dorks wish to return it to ash, just so the non-scientific hoi-polloi will throw dollars at them.
Obviously no one has ever read his Kelvin.
I'm reminded of the passage in Swift's 'Gullivers Travels', where the idiot scientists are trying to extract sunbeams from cucumbers.
Will not these Hydrogen scams ever die?
Good luck, gentlemen. I hope you get your tenure.
Posted by PercySludge
26th Oct 2010
+1 Vote
+ -
No one here understands
Recyclable energy storage medium. No carbon. So much for the dorks in the nasty peanut gallery. Of course it costs energy and then releases energy then can be recycled again and again by reconverting and so on. Lion quit the BS this does recycle. Energy intensive *good* so there is energy to be released and then input then released etc. Intensive energy is better than low energy where massive amounts of stuff have to be added to overhead.
Posted by Altotus
26th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
Wow, a lot of controversy over the least important parts of this?
Anywise, recycling technologies themselves need to be efficient
and cost effective, we all know this. So, my contribution here is
a statement by researchers working for Indium Corp which
refutes the author's about the 'supply issues':

"The abundance of indium in the earth?s crust is estimated to be
0.05 ppm for the continental and 0.072 ppm for the oceanic
crust. This concentration is higher than the concentration of
silver. Ulrich Schwartz-Schampera & Peter M. Herzig studied all
indium-containing ore deposits worldwide and reported their
findings in 2002 in their book titled ?Indium Geology, Mineralogy,
and Economics?. They concluded that ?future increases in
indium production are expected to be easily accomplished?
indium could enjoy virtually infinite growth in use without supply
limitations?."

Ok, someone else with direct insight? Let's work at moving this
article's content closer to an epiphany for the many readers who
are counting on us, OK?
Posted by DoctorEigenFlow
27th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
"We live in a world full of morons" no more comments please. it just stupidity to think of just, boats and ships, what about the rest of the world that live by the sea?
Posted by adelaidemark
27th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
Check this out: http://www.fsec.ucf.edu/en/consumer/hydrogen/basics/production.htm
and this:
http://en.wikipedia.org/wiki/Hydrogen_production
The real challenges for all hydrogen producers are pretty much the same: 1. Cost competitiveness of hydrogen vs. other energy source/storage products. 2. Minimizing the environmental impact of production and use of hydrogen as an energy source.
The biggest challenge to the hydrogen economy (real or imagined) is most likely that the highest demand users are the oil industry, which supplies the dominant energy source (Oil) for today's industries. They also exert a great deal of influence over the largest producers, since they are their largest customers. Today we buy Exxon/Mobil gasoline. Tomorrow, we will probably be buying hydrogren at Exxon/Mobile gas stations, or if you are lucky enough to live in Pennsylvania, from your local Wawa.
Posted by PSFTGURU@...
27th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
Actually, there are some very old technologies for powering boats and ships that are really very green. Wind power - sails, and following the natural currents in the ocean. For some interesting insight, read the book "1421 - the year the Chinese discovered America"
Posted by fred.wagner@...
27th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
The Al/Ga reaction is useful for more than ships.

You use the Aluminum to store solar energy by using it to smelt
the aluminum.

Then fill up your car's tank with tap water and drip feed it to the
AlGa powder.

Instant hydrogen and heat, on demand.

See, hydrogen is a pain to store.

As a liquid it is super cold and boils away quickly.

As a gas you have to squeeze it really hard and that wastes
energy as well as requiring a heavy tank.

And it tends to bleed through valves.

But as water ? Please !

Just add some antifreeze and you're good.

Feed the hydrogen straight to an IC engine or preferably a fuel
cell.

And you only make as much hydrogen as you will use, so none is
wasted.

The Al/Ga reaction is supposed to be about 70% efficient if you
can use the heat.

And that heat can be used to power air conditioning, a major
plus.

Eventually you pull the waste container with the oxidized AlGaO2
and drop it off for recycling and pick up another at the gas
station.
Posted by Jkirk3279
27th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
I haven't checked the thermodynamics of the processes but my gut tells me this is not a great idea. The hydrogen generation reaction should be something like:

4Al + 12H20 -> 6H2 + 4Al(OH)3
6H2 + 3O2 -> 6H20

The aluminum regeneration reaction something like:

2 Al2O3(cryolite) + 3 C(anode) ? 4 Al(liquid) + 3 CO2(g)

The aluminum hydroxide (Al(OH)3) would have to be converted to the oxide (Al2O3) for the regeneration reaction. For 6 moles of H2, you'd produce 3 moles of CO2 - the aluminum path is the same net reaction as burning methane.

3 CH4 (methane) + 6O2 -> 3CO2 + 6H2O

(It's been a long time since I last balanced equations, please correct me if I've made any errors - but you get the idea). I haven't considered entropy or the heat loss associated with all the reactions. For example, the aluminum reaction with water will be exothermic but the heat of reaction will be lost. Very inefficient.

Perhaps these Purdue academics have discovered some new chemistry that's not included in the blog.
Posted by 0David
28th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
"For example, the aluminum reaction with water will be exothermic
but the heat of reaction will be lost"

The heat won't be lost if you can USE it.

Five months out of the year a little heat is greatly appreciated here
in Michigan.

And it's possible to use heat to drive air conditioning too.

I note you didn't account for the gallium in the reaction. I realize it
is all recovered, just curious.

As for the carbon anode, you can't get something for nothing.

I've read that somebody found a way to use CO2 to make
hydrocarbons if you have enough electricity to drive the process.

CO2 may turn out to be quite valuable soon.
Posted by Jkirk3279
29th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
Jkirk3279

"The heat won't be lost if you can USE it."

True but we haven't found many ways of efficiently recovering low temperature heat. Examples: huge amounts of heat are lost from internal combustion engines, from the exit end of power station turbines ...

"I note you didn't account for the gallium in the reaction."

The article said the gallium's function was to dissolve the aluminum. I assumed it took no part in the chemical reaction.

"As for the carbon anode, you can't get something for nothing."

My point was that the aluminum "battery" scheme is not clean with water vapor as the only product. In part of the Al cycle, CO2 is produced in the same quantity as you'd get burning methane. Why go through a complex five or six step process with inefficiency at each step when you could just use methane in a single step.

"I've read that somebody found a way to use CO2 to make
hydrocarbons if you have enough electricity to drive the process.
CO2 may turn out to be quite valuable soon."

Given enough energy you can do almost anything but clean energy is what we're short of.
Posted by 0David
29th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
"Why go through a complex five or six step process with
inefficiency at each step when you could just use methane in a
single step."

Oh, well, that's easy. It takes a major chunk of energy to
compress methane enough to power a car.

You throw away about 30% of the energy compressing it.

I'm thinking a micro-turbine could recapture some of that, using
the compressed gas to make a little electricity.

But hey, I just heard there's a 5GW Concentrating Solar Plant
being planned in Africa.

If we build enough of those ourselves, we can do ANYTHING.
Posted by Jkirk3279
29th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
EDIT

For example, we could make methane from waste products and
CO2 from smokestacks, compress it and power all our cars that
way.
Posted by Jkirk3279
29th Oct 2010
+1 Vote
+ -
RE: Generating hydrogen from seawater to power boats
JKirk

J. Your pronouncements preclude reasonable debate. The "30% of heat of combustion lost compressing gas" is absurd. Compressing methane to 2400 psig (a typical cylinder pressure) costs costs a few kJ , ~1% of the 900 kJ/mole heat of combustion.

The discussion is off track. The topic is powering ships not cars, I mentioned methane purely to show that hydrocarbon combustion is about as clean as an aluminum "battery" in terms of CO2 pollution. Incidentally, hydrocarbons including methane are bulk stored as liquids not as compressed gases - with refrigeration as needed.
Posted by 0David
30th Oct 2010
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