Hydrogen car

Cool!

This uses the hydrogen production method currently being tested in Israel that was reported on a month or so ago. When I read about it, I didn't think it made sense for onboard hydrogen, but it looks like they found a way.

Basically, they use concentrated sunlight to vaporize zinc oxide in the zinc gas. They then condense the gas into pure powdered zinc. When the powered zinc is put into water, it creates zinc oxide and releases hydrogen. The zinc oxide is taken back to the solar tower to be revaporized back into pure zinc.

Very cool indeed.

 

What in the world would the car look like? Would it have to be as big as a Hummer in order to house the system?

 

Bill, you did read this right?
"Any reproduction or use of the materials on this website
without express written permission of IsraCast is prohibited."

 

Not necessarily. The acutal oxidation chamber wouldn't need to be very large, as they are only oxidizing a thin metal wire. It would push the wire into the oxidation chamber (perhaps as small clipped pieces) where it comes in contact with a little water and heat. The oxidation process removes the oxygen from the water molecules and releases the hydrogen. You would also need a water resevoir, but it looks like they plan to recycle the steam and water vapor from the fuel cell (or hydrogen combustion engine) back into the water resevoir. So maybe you would only need a fairly small resevoir that you top off every once and a while.

You would also need a bunch of batteries, like the Prius, because you have to heat the oxidation chamber to speed up the oxidation. However, hybrid technology makes as much sense on a hydrogen fuel cell vehicle as it does on a gas vehicle, so you would probably have a large battery array anyhow.

I have no idea if it's really truely practical, but the thought of using a common metal as "fuel" and recycling the waste product (the oxide) back into "fuel" using a solar tower, with little or no loss of the metal itself, is a very appealing idea.

 

It takes a lot of electric energy to split hydrogen from Oxygen in water. Most Hydrogen is made from natural gas or methanol which are fossil fuels.
A hydrogen fuel cell takes time to get to operating temperature and really just runs an electric car. If you us battries like lithium-ion to store and use the electric it's 4 times more efficient than hydrogen fuel cell EV's.
We already have the technology for battery electrics but hydrogen fuel cells are 5-10 years away.
Check out the plugin Prius hybrid for real efficiency at calcars.org
Jim

 

He is the Bill Merchant you know...


h34r:

 

<_< No matter how efficient this design may be, it's still essentially solar powered and, therefore, its maximum power is determined directly from how much solar energy it harnesses.
Solar radiation at 100% efficiency is generally in the 600 watts per sqare meter range.
1 watt = 0.001341 horsepower [international].
You'd need a heck of a lot of panels to power a car.

 

You missed the point. Nobody is using electricity to split hydrogen from water in this scenario.

Instead they use concentrated sunlight (effectively a big magnifying glass) to vaporize zinc oxide and then condense the zinc gass into pure powdered zinc. Then then form this powered zinc into a wire. The wire is the "fuel" for the car.

The car adds water and a little heat to the wire, which causes the wire to oxidize (rust). Oxidation means that the oxygen molecules from the water bond to the zinc molecules, thereby releasing hydrogen. The released hydrogen is then used to power the fuel cell.

It wouldn't take much energy in the car to split oxygen from water using the zinc, because zinc has a lot of potential energy in it. Zinc wants to rust and will do so quite readily. Adding a little heat speeds up the process.

The result is zinc oxide, which is then shipped back to the solar tower and turned back into pure zinc.

It takes a lot of energy at the solar tower to convert the zinc oxide to pure zinc, but you're using solar energy and in a way that is probably more efficient than converting it to electricity.

And even if this doesn't become an in-car solution, the oxidation and hydrogen release could be done a filling station instead.

 

Still, essential solar power.
You can't get something from nothing.
You don't get more energy from sunlight by concentrating it.
The amount of energy you store by splitting off the hydrogen in this system comes from sunlight.
That's the maximum you could get out of it at 100% efficiency (which cannot be reached).

The site is probably either promoting free energy quackery or its a scam or both.

 

It's not as bad as you imply. You are implying that since 1 watt equals 0.001341 horsepower, and you would need a whole lot of solar panels to get something like 100 hp. Right?

The flaw in your argument is that a car does not use it's maximum rated horsepower continuously every minute of the day, 365 days a year.

So, lets assume a viable EV car would require a 50 kWh battery to go 300 miles. (there have been many articles and discussions that arrive at that number). Lets further assume that the average car owner travels 12,000 miles a year.

So, after a little math, you will find that the average EV car described above consumes 2 MWh (megawatt hours) of energy each year. Therefore, it would average 5.5 kWh of energy each day.

So, now lets go with your 600 watt per square meter number and assume, for the sake of convenience that we are 100% efficient in converting solar energy into energy used by the car. Lets further assume that a solar panel would get usable sunlight only 10 hours a day.

Therefore, your one square meter solar panel, producing an output of 600 Watts, would produce 6 kWh a day.

Voila! An EV car needs only 5.5 kWh a day, so it only needs a one square meter solar panel to meet it's energy needs. Now, if you account for energy conversion inefficiencies, then maybe it really needs 2 or 3 square meters of solar panels. Even if you up it to 9 square meters, that's still only about the size of the floor of a small bedroom.

That's really not that much.

 

3 Square meters might be doable on a car.
6KWh per day (good weather) IN with 5.5 kWh per day OUT doesn't leave much margin for weather.
Presumably, you'd have to store enough zinc powder for a couple of days of poor weather use.


I'll assume, for the sake of discussion, that you are correct that an automobile can get enough energy from the sun.

The question becomes "Which energy storage device provides the highest efficiency for storage and retrieval?"

Typically, batteries are used to store electric energy.
This is a fairly mature technology and its efficiencies are known.

In the zinc/hydrogen scenario, zinc powder becomes the medium for energy storage.
What kind of efficiency does this system offer.

I'm going to jump to the conclusion for now that conversion of solar energy directly to electricity and storage and retrieval to a battery will have far greater efficiency than this zinc/hydrogen system.
I wouldn't mind being wrong though. Better is better.

 

It's not a hydrogen car, it's a reactive metal car. Artificial liquid hydrocarbon fuel can be made and distributed more easily and cheaply than this fuel, with no changes to the distribution system or to cars.

 

Weather is not an issue, because you are not distributing individual solar panels around the globe, one per car.

Instead, you build solar towers with tens of thousands of square meters of mirrors that are aimed at the tops of the towers. You use the heat from the concentrated sunlight to refine zinc oxide into zinc.

Furthermore, you put these solar towers in desert areas near the equator, such as africa, australia, the Middle East, and even Mexico/SouthWest US. Such areas get the maximum strength sunlight and few clouds.

The zinc powder can then be easily transported to the point of consumtion. The waste zinc oxide is likewise shipped back to the solar tower.

So how would you get massive amounts of solor energy generated electricity from the Sahara or Australia to the NorthWest US?

 

I reread the article more closely and out of context of the PC posts and agree with Richard Schumacher. Although the car would burn hydrogen, its fuel is coiled metal.

"Refuelling the car based on this technology will also be remarkably simple. The vehicle will contain a mechanism for rolling the metal wire into a coil during the process of fuelling and the spent metal oxide, which was produced in the previous phase, will be collected from the car by vacuum suction."

So I take back my erroneous conclusion that this would be a solar powered vehicle.
It would be an alternative fuel vehicle.
It's fuel would be Zinc (not hydrogen).
True, hydrogen would be burned to turn the wheels but this is analagous to burning diesel in a locomotive to turn a generator to power its electric motors.

 

Well, I guess it's all how you look at it. It's hydrogen that is actually being combusted or used in a fuel cell. The zinc (or other metal) is just the energy carrier. It's kind of like a battery and it's "rechargable". You "charge" it by removing the oxygen molecules (zinc oxide -> zinc), and you "discharge" it by adding the oxygen molecules back in (zinc -> zinc oxide). The zinc itself is not consumed, it's all still sitting in the "tank".

Lets say you built an EV car that uses replacable NiMH battery packs. You pull into the "filling station" and they pop out the spent battery pack and put in a fresh one. Then the used battery pack is sent back to the factory to be recharged. Would you consider it's fuel to be NiMH?

After all, electricity is stored in a battery by changing the chemical properties of the materials inside the battery. It's not a jar of electrons.

 

If I understand the article correctly, the zinc is consumed and the waste product (zink oxide) is removed and recycled when you "fill up" again with new pure zinc wire.
When you run out of zinc, the system stops.
The hydrogen in this car is only a conduit for the energy from the oxidation of the zinc. It is not the vehicle's fuel.

Most fuels operate by harnessing the energy released by changing chemical composition.

When you burn gasoline, its atoms still exist, and, if you wanted, you could "recharge" them by putting them back into their original gasoline configuration.
This would be equivalent to your example of recharging the zinc.
The chemistry is just much simpler.

The first source for the energy to create the zinc as fuel described in the article would be solar.
It could just as easily be wind, geothermal, nuclear, coal, oil...

A vehicle using this system would produce no emissions. That's a good thing.
Are zinc and zinc oxide safe materials?
How common is zinc?

 

Zinc Oxide is the main ingredient in the dorky white sunscreen that people put on their noses while at the beach. Zinc is a common metal I believe. It's used in things like coins so it must be cheap/abundant.

BTW here's a blurb from the Union of Concerned Scientists website about solor

Here's a link to a Solar tower/Zinc article:

http://www.renewableenergyaccess.com/rea/news/story?id=36544

And finally.... some "facts about zinc":

http://www.galvanizeit.org/showContent,35,67.cfm

 

the zinc is just a catalyst, its not the fuel. and for the record, i do not believe there is any combustion inside a fuel cell. and thirdly, the above diagram does not show a fuel cell. Hydrogen is not the same thing as a fuel cell. Hydrogen fuel cells currently operate at 40% efficiency, PEM type. If Li-ion batteries were 4 times more efficient then i'd like to know what happened to the law of conservation.

 

The Hydrogen is not the fuel in the process described.
A catalyst is not consumed by the reaction to which it reduces the activation energy.
Fuel is the material from which energy is being released.
In this case, the energy comes from the oxidation of the zinc.
The zinc in the process described is consumed (oxidized) and becomes zinc oxide.