Piezo Crystals Harness Sound To Generate Hydrogen

MikeChino writes "Scientists at the University of Wisconsin-Madison have discovered that a mix of zinc oxide crystals, water, and noise pollution can efficiently produce hydrogen without the need for a dirty catalyst like oil. To generate the clean hydrogen, researchers produced a new type of zinc oxide crystals that absorb vibrations when placed in water. The vibrations cause the crystals to develop areas with strong positive and negative charges — a reaction that rips the surrounding water molecules and releases hydrogen and oxygen. The mechanism, dubbed the piezoelectrochemical effect, converts 18% of energy from vibrations into hydrogen gas (compared to 10% from conventional piezoelectric materials), and since any vibration can produce the effect, the system could one day be used to generate power from anything that produces noise — cars whizzing by on the highway, crashing waves in the ocean, or planes landing at an airport."

Comments

Thermodynamics

[Sarten-X]

It sounds (no pun intended) like this material would have to absorb energy from the sound wave. I wonder how well it would work as an acoustic barrier bordering a highway. It'd be refilled by rain, powered by noise, and it might just block the sound better than those lovely concrete walls we have now.

Re:Thermodynamics

[JWSmythe]

    The #1 problem here would be.....

    If you had an infrastructure where highway barriers were full of water, generating a perfectly combustion mixture (like, not just good, but perfect) flowing into pipes, which would (obviously) need to be somewhere close to the road. If they are elevated, they run a risk of contact with a vehicle, or flames from an accident. I've seen bridges melt from accidents under them. Below the road, the gases rising create an extreme explosion hazard at ground level. One cigarette butt thrown out a window, and you could have an entire highway explode.

    Anywhere around a highway is a potential heavy impact and fire hazard. If you watch the news, you'll see the "freak" accidents where cars leave the road and end up in houses or other buildings, or burst into flames for various reasons. Anyone who's worked for a while as in the emergency response industry (police, fire, paramedics) have seen vehicles on their roof. Thousands of pounds of pressure may break a pesky hydrogen pipeline.

    I'm not against it though, it sounds like an interesting idea, although not a solution. If cars were powered by hydrogen instead of gasoline, and the noise on highways produced hydrogen to power them, the evil laws of thermodynamics jump in and say "don't get your hopes up."

Wall linings

[Trogre]

If these can be manufactured cheaply enough, I imagine boards of this being made and marketed by Gib for any place where you want soundproofing or a room with 'dead' acoustics.

Re:Whats the real efficiency...

[crazybit]

In this discovery they use sound waves to get hydrogen (which you can later use to make electricity or move cars). Sound waves are being generated all over nature as a natural left over of different processes. On the other hand electrolysis requires electricity, which has a cost in our modern economy.

You should measure not only the efficiency, but the total cost of energy generation.

This weeks Green Energy Hype

[jmorris42]

So this was the best Slashdot could come up with for this weeks Green Energy Hype of the Week? Guess it was a slow week because this one is lamer than most.

Ok, ASSuming they can figure out a way to separate the H and O before they just combine again. ASSume this tech actually works outside the lab and can be scaled up. ASSume it performs as advertised when scaled up. 18% conversion efficiency on sound waves? Sound doesn't carry a lot of energy to begin with and they will harvest 18% of it before losses in compressing the H. Oh wow, if we ran this stuff down a mile of busy highway we MIGHT generate enough energy to push one crappy green gocart/car down that highway every day.

And that is the problem with most alternative energy schemes, they depend on ignorant people who don't know how the world works. There are LOTS of ways to extract energy from nature. The problem is that there aren't many that can compete with the existing sources because they are just so darned good, which was why we standardized on them in the first place. And if we actually do find a new good source, once scaled up it is a veritable certainty that we will discover that it too isn't a free lunch and that it also has a downside somewhere. And the second certainty is that the Greenies will be working to ban it because if it actually works it won't be alternative anymore. Kinda like music, when that great alternative/undergound band signs a contract and releases a hit most of their original fans declare them 'sellouts' and glom onto the newest unheard of band.