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New bio fuel cell prototype does away with platinum-based catalysts and fuel-separation membranes

Pulling electricity out of air may be a feasible option in the future according to researchers at Oxford University. Fraser Armstrong, Ph.D. and his research team have managed to develop a revolutionary bio fuel cell which promises clean and renewable energy.

The bio fuel cell contains two electrodes that are covered with oxygen-sensitive FeFe hydrogenase enzymes. The enzymes are attached to the electrodes using strong covalent and non-covalent linkages to allow for fast electron transfers. The electrodes and enzymes are then placed within a container of air which has a 3% mixture of hydrogen.

Current testing shows that the prototype fuel cell is capable of powering small electronic devices such as a wristwatch.

"We are at the tip of a large iceberg, with important consequences for the future, but there is still much to do before this generation of enzyme-based fuel cells becomes commercially viable," said Armstrong. "The idea of electricity from hydrogen in air, using an oxygen-tolerant hydrogenase is new, although other scientists have been investigating enzymes as electrocatalysts for years. Most hydrogenases have fragile active sites that are destroyed by even traces of oxygen, but oxygen tolerant hydrogenases have evolved to resist attack."

Armstrong notes that typical hydrogen fuel cells require expensive metals like platinum ($1,000 USD per ounce) to serve as a catalyst for electricity production. Hydrogenases also have roughly the same productivity rate as platinum-based catalysts and do not require complex fuel-separation membranes to operate.



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Not quite "thin air"
By masher2 (blog) on 3/30/2007 12:43:41 PM , Rating: 2
The electricity is generated from air to which a 3% hydrogen mixture has been added...so not quite energy out of thin air.




RE: Not quite "thin air"
By Hulk on 3/30/2007 12:55:05 PM , Rating: 1
Exactly. And the power for a LCD watch is virtually nothing. Any galvanic reaction could do the same thing but we don't have galvanic power plants do we?

This will never see the light of day for commercial application.

It's good to explore all avenues but I hope not too much money is being spent on this.


RE: Not quite "thin air"
By Xavian on 3/30/2007 2:01:44 PM , Rating: 5
Everything has to start somewhere, my friend.

I suppose if you were around when the first combustion engines were made, you would of said 'look! this thing will never match steam engines in speed or power!'

Just because its a new technology and doesn't produce a lot of power to begin with, doesn't mean that it isn't worth more investigation that could lead to a breakthrough in Fuel Cells, for all technology has evolved from something that is lesser.


RE: Not quite "thin air"
By TimberJon on 3/30/2007 3:00:41 PM , Rating: 2
Yea cmon man. Don't slap it down like you know for certain that its development, or offshoots of its development won't become fruitful.

Dozens of technologies today were stumbled upon accidentally. Sometimes an offshoot, and sometimes an offshoot of an offshoot. Tip of the Iceburg experiments are worth keeping an eye on. A theory is different from a lab product that is proving the theory, and supplying raw data.


RE: Not quite "thin air"
By masher2 (blog) on 3/30/2007 3:12:21 PM , Rating: 2
I can see potential uses for it. Imagine a home or office building with a hydrogen generator in it, constantly keeping a low-H2 mix distributed throughout the building. Now, you can replace all your battery-powered (and low-draw "wall-wart" powered) devices with this instead, eliminating the need to ever change batteries or run wires. You'd obviously lose some energy through convection with the outside air, but you'd gain a great deal in convenience and simplicity. And, if one assumes the enzyme-based cells were highly-efficient, you might even wind up saving on energy costs.

Obviously, the generator would require some automatic safety features, but otherwise the scheme appears feasible.


RE: Not quite "thin air"
By Oregonian2 on 3/30/2007 4:25:28 PM , Rating: 2
Why would one want to use a box of hydrogen (or even batteries) to replace a one-dollar non-explosive, wall wart in a home that will have to be recharged when it runs out of hydrogen fuel someday? This hydrogen device is a battery of sorts.


RE: Not quite "thin air"
By masher2 (blog) on 3/30/2007 4:32:27 PM , Rating: 2
You misunderstand how it would work. You wouldn't keep a "box of hydrogen"; you'd have a generator costing a few hundred dollars permanently installed. It would generate hydrogen directly from water, itself supplied via tap. No boxes or batteries to refill or replace, ever.

If you only had a single "wall-wart" to replace, such a system wouldn't even be close to feasible. However, I easily have 100 of the things in my home, not to mention a few dozen battery-powered devices. Replacing all of them with a system that needed no wires and never needed replacing would be a huge step forward.


RE: Not quite "thin air"
By Oregonian2 on 3/30/2007 7:08:59 PM , Rating: 2
Ah! You use wall electricity and piped in water to produce a chemical hydrogen battery of sorts which you then use to produce electricity to power things via wires one runs through the house from the hydrogen unit. Or perhaps a power over power unit can be made to distribute that hydrogen generated electricity over the house's built-in power lines. Sorry I misunderstood! Or does one pipe the hydrogen through the house through hydrogen lines so one can produce electricity at the end points only? I don't think this would work well in my house.


RE: Not quite "thin air"
By masher2 (blog) on 3/30/2007 7:31:26 PM , Rating: 2
I was envisioning direct release of the hydrogen into the air...probably via a small connection into your HVAC system, to ensure good circulation.


RE: Not quite "thin air"
By borismkv on 3/30/2007 9:56:36 PM , Rating: 2
I'd hate to see what happens to the house that catches fire with that mixture. Or the people who live there.


RE: Not quite "thin air"
By masher2 (blog) on 3/31/2007 7:58:35 AM , Rating: 2
> "I'd hate to see what happens to the house that catches fire with that mixture"

You didn't read the thread. A 3% H2 mixture is too low to support combustion.


RE: Not quite "thin air"
By Oregonian2 on 4/2/2007 3:23:45 PM , Rating: 2
Doesn't mean that it doesn't burn if combustion is being supported by something else.


RE: Not quite "thin air"
By Oregonian2 on 4/2/2007 3:28:15 PM , Rating: 2
As well as health concerns (long term breathing of gaseous hydrogen?). As well as having to use a LOT of hydrogen, most houses -- despite seemingly sealed -- "leak" 100% of their air every few hours (or some number like that). More if somebody opens a few windows on a nice summer day, or a sliding glass door to the deck (something we have).


RE: Not quite "thin air"
By masher2 (blog) on 4/2/2007 5:26:16 PM , Rating: 2
> "Doesn't mean that it doesn't burn if combustion is being supported by something else."

Not sure of your point. The oxygen in air burns also...if that combustion is being supported by something else. The point is that a 3% mixture doesn't increase in any way the risk of explosion or fire.

> "As well as health concerns (long term breathing of gaseous hydrogen.."

None. Hydrogen is a simple asphyxiant...dangerous only in concentrations high enough to supplant oxygen entirely.

> " most houses -- despite seemingly sealed -- "leak" 100% of their air every few hours"

A well-sealed home is actually on the order of a few days. Many office buildings are significantly less than that...which is why an office is probably a better environment for this.

In any case, your standard "wall wart" usually pulls a few watts of power...even when the device it powers isn't active. When it is active, most of them are extremely inefficient, often well below 50%.

So while the H2 approach certainly wastes some energy, I don't think the differential is nearly as large as you might think.


RE: Not quite "thin air"
By Oregonian2 on 4/3/2007 2:25:44 PM , Rating: 2
quote:
> "Doesn't mean that it doesn't burn if combustion is being supported by something else."


Things that are 'flame retardant' won't sustain combustion, but if put into a flame they certainly do burn. Not sure if that's the right term to use or even what would happen with a 3% hydrogen atmosphere next to the fireplace that's roar'ing away. Our house has two of them.

As to houses, my understanding is that a typical house has a full recycling of air 3~5 times a day. And yes, modern office buildings can be much tighter than that (causing unhealthy air, I understand), although probably not near the doors. :-)

Air turnover can be quickened further when one turns on the outdoor venting fan in the kitchen while cooking or in bathrooms when the outdoor-going vents are turned on, or when a clothes dryer (also blowing air outdoors) is running -- and that one, at least ours, blows a LOT of air and does it the whole time it's running (which seems like forever -- and daily).


RE: Not quite "thin air"
By ralith on 3/30/2007 10:16:59 PM , Rating: 3
Wouldn't the hydrogen tend to pool at the ceiling? How would it stay mixed? What the heck is a "wall-wart"? A fire alarm?

Now the big question! Is 3% hydrogen enough to make your voice all high pitch like when you've sucked in from a helium ballon? That'd be hilerious.


RE: Not quite "thin air"
By masher2 (blog) on 3/31/2007 7:56:55 AM , Rating: 1
> "Wouldn't the hydrogen tend to pool at the ceiling?"

No. Once mixed, two gases stay mixed. Otherwise, all the oxygen in our atmosphere would settle to the bottom, leaving nothing but nitrogen in the upper atmosphere.

> "What the heck is a "wall-wart"?

Colloquial term for the wall-socket transformer that powers consumer devices.


RE: Not quite "thin air"
By AnotherGuy on 3/30/2007 1:00:15 PM , Rating: 2
Still not so hard to achieve... u could create the battery with a small container of hydrogen in condensed form... which is released to the small main container of regular air up to 3% in volume... IF the whole idea is worth it.


RE: Not quite "thin air"
By Oregonian2 on 3/30/2007 1:03:21 PM , Rating: 2
Also seems mostly worthless from a commercial viewpoint. The energy density of 3% hydrogen gas doesn't seem useful as well as something that sounds dangerous. If a match were put to that container.....??

The best I could see is to have a "combustion" (of sorts) chamber that is filled with surrounding air and a compressed hydrogen container releasing a bit into it, then converting until another batch is needed. Still doesn't sound very practical though.


RE: Not quite "thin air"
By masher2 (blog) on 3/30/2007 1:33:18 PM , Rating: 2
> "If a match were put to that container.....??"

That's really the point of this research. A 3% hydrogen concentration is too low to sustain combustion, so there's no danger whatsoever.


RE: Not quite "thin air"
By saratoga on 3/30/2007 2:54:12 PM , Rating: 3
The threshold is 4%, which is dangerously close. It would not take much to push you over that threshold. It will also limit the available power density, since most applications are likely to have serious reservations about keeping combined hydrogen oxygen mixtures anything close to the 4% mark.


RE: Not quite "thin air"
By masher2 (blog) on 3/30/2007 2:59:28 PM , Rating: 2
> "The threshold is 4%, which is dangerously close. It would not take much to push you over that threshold..."

It doesn't work like that, thanks to the law of entropy. If you have a hydrogen (or any gas) in air at a given partial pressure, the only thing that can increase it is coming into contact with a more concentrated source. It can't spontaneously happen. Period.

No matter how much of this hydrogen mix you have on hand, its totally safe...as long as all of it is kept below the 4% mark.


RE: Not quite "thin air"
By Oregonian2 on 3/30/2007 4:30:26 PM , Rating: 2
The only practical implementation would have some pure hydrogen in a container that feeds into a chamber with outside air. You then have the more concentrated source, and also the possibility of a mix that's wrong. Yes, one could perhaps have the already diluted 3% hydrogen air in a compressed vessel but that seems to be REALLY inefficient in terms of energy density for the device as a whole. One then has to have a lot of air be part of the fuel. Imagine if the gas tank of an auto had to include all the air that's used in its combustion.


RE: Not quite "thin air"
By masher2 (blog) on 3/30/2007 4:36:45 PM , Rating: 2
> "The only practical implementation would have some pure hydrogen in a container... "

Or hydrogen generated on-the-fly via electrolysis or some other approach. But even in the bottled-hydrogen approach, dispensing a mix limited to a 3% concentration is easily done, and would be no more dangerous than having a few bic lighters in your home (themselves filled with highly flammable butane).


RE: Not quite "thin air"
By Oregonian2 on 3/30/2007 7:15:05 PM , Rating: 3
But what's the point of using electricity to produce hydrogen to produce electricity? I can build a nearly 100% efficient scheme very cheaply to go direct from the input electricity to the output electricity: a wire. Passing through the hydrogen stage in between will be much less efficient (unless it's converting mass to energy in the process, and I don't think that was being claimed).


RE: Not quite "thin air"
By masher2 (blog) on 3/30/2007 7:29:59 PM , Rating: 1
Mobility and the lack of a tether are the primary advantage. You're right it takes a hit in the form of efficiency. (though a dc-dc converter and a long, high-gauge wire is far less efficient than you might think.)


RE: Not quite "thin air"
By Fritzr on 4/8/2007 7:05:41 AM , Rating: 2
The hydrogen is vented into the room somewhere. This source will have a local concentration that is higher than the average. perfect mixing is great for simplifying calculations. In real life it rarely happens. Each time fresh gas is vented into the room the percentage will be much higher than the room average until the gas has a chance to mix with the air into which it has just been injected. It could be blended with nitrogen which would reduce the oxygen concentration while mixing progresses.

There may be something here. Some of the early internal combustion engines were just steam engines with gas injected into the cylinder and fired. They tended to fail explosively. Now people think internal combustion is safe & it's steam that may explode ... times change as technology is developed.


RE: Not quite "thin air"
By Seemonkeyscanfly on 3/30/2007 3:08:47 PM , Rating: 2
So if I eat 3 lbs of mixed bean and 2 hours later I’m adding high level of methane gas to the air every ohhh..say 2 minutes, in a 15 foot by 20 foot, by 9 foot room, at what point should I fear for my life? I mean one spark and it’s all over.

Really wouldn’t static electricity be higher in this environment, that is more and/or bigger shocks?


RE: Not quite "thin air"
By Oregonian2 on 3/30/2007 4:31:35 PM , Rating: 2
If my wife were nearby, your live would DEFINITELY be in danger!


Eliminate Pt
By TheTerl on 3/30/2007 12:59:24 PM , Rating: 3
I'm only lukewarm to the part about these devices running in air with 3% hydrogen, since only trace amounts of hydrogen are present in the atmosphere. What I'm very interested in, though, is the prospect of these enzymes replacing platinum in a more conventional fuel cell design. My recollection is that one of the biggest hurdles (aside from cost, which is certainly non-trivial in its own right) is certain compounds, such as sulphur, poisoning the catalyst. These new catalysts have the potential to eliminate that issue.




RE: Eliminate Pt
By rainwater on 4/2/2007 5:04:10 PM , Rating: 2
Why is it nobody else commenting on this story grasped the crux of the article? The idea is about replacing platinum as the catalyst and the only reason they had it open to the air to prove that oxygen wouldn't posoin their enzymes.


RE: Eliminate Pt
By rainwater on 4/2/2007 5:05:40 PM , Rating: 2
Why is it nobody else commenting on this story grasped the crux of the article? The idea is about replacing platinum as the catalyst and the only reason they had it open to the air to prove that oxygen wouldn't posion their enzymes.


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