Is This For Real-- A Car That Runs 200 Miles On Compressed Air?

[John317]

What do you think?

See video at: http://got2begreen.com/car-that-runs-200-miles-on-compressed-air/

By Matt Sullivan

Published in the June 2007 issue.

India’s largest automaker is set to start producing the world’s first commercial air-powered vehicle. The Air Car, developed by ex-Formula One engineer Guy Nègre for Luxembourg-based MDI, uses compressed air, as opposed to the gas-and-oxygen explosions of internal-combustion models, to push its engine’s pistons. Some 6000 zero-emissions Air Cars are scheduled to hit Indian streets in August of 2008.

Barring any last-minute design changes on the way to production, the Air Car should be surprisingly practical. The $12,700 CityCAT, one of a handful of planned Air Car models, can hit 68 mph and has a range of 125 miles. It will take only a few minutes for the CityCAT to refuel at gas stations equipped with custom air compressor units; MDI says it should cost around $2 to fill the car’s carbon-fiber tanks with 340 liters of air at 4350 psi. Drivers also will be able to plug into the electrical grid and use the car’s built-in compressor to refill the tanks in about 4 hours.

Of course, the Air Car will likely never hit American shores, especially considering its all-glue construction. But that doesn’t mean the major automakers can write it off as a bizarre Indian experiment — MDI has signed deals to bring its design to 12 more countries, including Germany, Israel and South Africa.

Source and much more on topic: http://www.popularmechanics.com/automotive/new_cars/4217016.html

[Dr. Shane]

The version they are planning to release in the US in 2010 has a multi-fuel air compressor which holds eight gallons of fuel. When the air tank's pressure runs down it kicks in to recharge the tank. One gallon of gas or diesel will compress enough air to go just over 100 miles. So it will tout 100+ miles to the gallon. It can also be charged up at home with the electric compressor that takes 4 hours or filling stations with a compressor will be able to charge the tank for those not wanting to use gas.

[John317]

Hope they hurry. I was kinda dreaming of getting two this year. I need it yesterday. LOL

I heard also something about the possibility that they will install a generator in the car so it can continually recharge the tank. But I suppose that is hoping for too much!

[Amelia]

All glue? Wonder what happens during the monsoon season?

[John317]

Here's some more info on the air-car:

The Air Car is the wider name for a number of models planned for production by MDI, including a 3-seat MiniCat due for 2008 and a 5-seat CityCat, among others. Their engines will either be dedicated compressed air engines—which release compressed air to activate the pistons—or dual fuel engines, using both compressed air and conventional gasoline. Either way, it’s hard to argue with compressed air as a clean, abundant, and inexpensive fuel source.

What We Like

• The price. Depending on the model, these will retail for about $12,500 up to $16,000

• The performance. The MiniCat, running only on a compressed air engine, has a top speed of 68 mph and a range of as many as 120 miles.

• The recharge. Overnight at home, it will require about 4 hours. At a proposed recharging station, as a few as 4 minutes

• The oil needs. A liter of vegetable oil can last the vehicle about 31,000 miles.

• The emissions. At the tailpipe, emissions are zero. However, air compression—whether done at a station or at home—requires electricity, which is typically generated using fossil fuels.

What We Don’t Like

• The construction. These all-fiberglass cars are glued together, meaning they have little hope of finding their way to America, where additional sales could mean a huge boost to alternative fuel vehicles.

• The design. This may seem like nit-picking or like asking too much, but the proposed model designs bear a lot in common with the ugly functionality of Neighborhood Electric Vehicles.

[melvin mccarty]

I have an air compressor with a small tank in which the compressed air is stored at up to 125 psi. It will run my air wrench for a couple of minutes before the compressor starts. If the power is off my wrench very soon becomes useless. The small storage tank is quite heavy for it's size in order to be safe at 125 psi.

In short... someone is having fun pulling your leg my friend...better you stay with theology! mel

[melvin mccarty]

Do the math! A tiny 50 cc engine at 5000 RPM would use how many litres of air in an hour? How big a tank would be required to store that many litres of comressed air? And performance would drop at a flat rate from max pressure down to zero.

mel

[Dr. Shane]

It is no joke. Here is the article from Popular Mechanics.

Air-Powered Car Coming to U.S. in 2009 to 2010 at Sub-$18,000, Could Hit 1000-Mile Range

Quote:

Zero Pollution Motors (ZPM) confirmed to PopularMechanics.com on Thursday that it expects to produce the world’s first air-powered car for the United States by late 2009 or early 2010. As the U.S. licensee for Luxembourg-based MDI, which developed the Air Car as a compression-based alternative to the internal combustion engine, ZPM has attained rights to build the first of several modular plants, which are likely to begin manufacturing in the Northeast and grow for regional production around the country, at a clip of up to 10,000 Air Cars per year...

Company officials want to make the first air-powered car to hit U.S. roads a $17,800, 75-hp equivalent, six-seat modified version of MDI’s CityCAT (pictured above) that, thanks to an even more radical engine, is said to travel as far as 1000 miles at up to 96 mph with each tiny fill-up.

We’ll believe that when we drive it, but MDI’s new dual-energy engine—currently being installed in models at MDI facilities overseas—is still pretty damn cool in concept. After using compressed air fed from the same Airbus-built tanks in earlier models to run its pistons, the next-gen Air Car has a supplemental energy source to kick in north of 35 mph, ZPM says. A custom heating chamber heats the air in a process officials refused to elaborate upon, though they insisted it would increase volume and thus the car’s range and speed.

Couple of things. If it takes four hours to compress the air in the tank with 110 volt the pressure is going to be well above 125 psi. Secondly, there is some kind of a heat chamber the makes the air expand before going into the engine. These guys are thinking outside the box.

The "glue" is probably a type of epoxy. As long as it can pass the safety tests it is undergoing it shouldn't be an issue.

[John317]

Thank you, Shane. My reason for posting it here was to bring out these very kinds of discussions and points.

Even if it does not prove to be "the solution," it seems to me to be a good beginning contribution to the effort of finding solutions.

[melvin mccarty]

Consider a 10 cfm compressor running steady for 4 hours ..2400 cubic feet. How big is that tank and what does it weigh? Do the math!

mel

[Bravus]

Quote:

fill the car’s carbon-fiber tanks with 340 liters of air at 4350 psi

(for those who missed it in the original article)

It's definitely an interesting technology. Like hydrogen, it's only an energy transfer tool, not an energy production tool. But within that it's interesting - and compressed air is lighter than the batteries in an electric vehicle.

[Dr. Shane]

However if the electricity is being generated by a clean source, this is a good solution.

[melvin mccarty]

How much will storage tanks weigh that will hold a pressure of 4350 psi? How much heat (wasted energy) is generated in a 4350 psi compression and where will you find all those compressors capable of attaining that pressure? Not in any old garage or handymans basement. Must be uncomfortable to hold your tongue in your cheek so long....lol mel

[olger]

Some sort of heavy duty screw compressor with a generous reduction chamber...

About a 45:1 ratio - it could be done.

[melvin mccarty]

It could be done could it? And the heavy duty fittings and hoses to handle the pressure? And is that all included in the cost of the vehicle? So if you were to buy said vehicle you would also need all that other expensive high pressure equipment that does not now exist. And make sure wherever you go someone will be able to recharge your tank. Did you notice the big grin on the face of the guy in the video? How about testing and licencing those extremely high pressures?

Have fun!!

mel

[Dr. Shane]

The high pressure equipment already exists. It is used for power storage by wind turbines and a few power plants in Germany and here in the US.

[olger]

I anticipate that they would regulate the pressure down right out of the tank, like oxygen or nitrogen tanks. We have several nitrogen tanks that we use to blanket moisture sensitive drums. They come at about 2500 psi, I believe.

I'd have to know more about the air car. I understand your questions Melvin, and we don't know all the specs yet. It's Interesting.

oG

[Dr. Shane]

If one compressed air enough it becomes liquid and air is 70% nitrogen so that gives us an idea of what is going on. There is also an Australian car company working on a rotary air motor but it is not as advanced as MDI's.

[melvin mccarty]

Yes I have used many "bottles" of oxygen and acetelene etc. and I know what those containers weigh. A few cubic feet of gas at around 2500 psi comes in a very strong container which is relatively very heavy. If there are new materials which are really strong enough and light enough to make the air car practical why are we not using them in the bottled gas industry and saving millions in freight costs?

mel

[Dr. Shane]

The tank is made out of carbonate and is made to split during an accident thus allowing the air to escape safely. I haven't read how fragile the tanks are but I would imagine the steel tanks compressed gas is stored in is not nearly as fragile.

[Bravus]

At those pressures any air escape would basically be an explosion and would turn the car briefly into a rocket...

[Bravus]

Time to bust out the calculator, methinks...

[Bravus]

Quote:

340 liters of air at 4350 psi

Hmm. Since normal atmospheric pressure is about 15 psi, this is 290 atmospheres of pressure, which is pretty extreme. And if that 340 L of air was measured at normal pressure, then the tank would only be about 1.17 L in size once the air was compressed.

That seems pretty tiny, so let's try it the other way around (which makes more sense in terms of the energy to run a car: assume the tank itself is 340 litres. That's pretty big - about one and a half 44 gallon drums.

But if that's the case you'd have the equivalent of 98,600 L of air at normal pressures compressed into the tanks. That's about 4,400 mol of gas. If we treat air as being all nitrogen (which is fairly close), that's 4,400 x 14 x 2 = 123,250 grams = 123 kg of air, which is not too bad, although it's a lot more mass of fuel to lug around when full than a tank of petrol.

{to be continued}

[Bravus]

Have to admit, I'd only read the thread, not watched the video. The video showed the size of the tanks, and the 340 L tank size seems about right. But the video was also filled with extremely bad science (perpetual motion?) and plain nonsense (free fillups).

The concept itself, separate from its promotion by people who don't understand the science and technology, is a very intriguing one... but it's still only an energy transfer technology, and the original energy has to come from somewhere. As Shane pointed out, the possibility of coupling this technology with clean energy generation is also there, but I suspect technologies that provide clean energy directly in cars might have more potential... or hydrogen solutions. After all, no matter what we say about the strength of the tanks, that much pressure is basically an explosion waiting to happen... and as Mel has pointed out, most of our current solutions for solving that problem are made of large masses of metal. So really, the key technology here might be, not the engine, but the 'fuel' tanks.

[melvin mccarty]

Right on Bravus!

Let's do some rough calculations!

A 1 litre engine running @ 2000 rpm (2 cycle basis)@ 200 psi would use 2000 litres per minute. Your 340 litre tank reduced to 200 psi would give you around 7000 litres. Have I made a mistake here somewhere Bravus? What does your calculator say?That would give you less than 4 minutes run time. mel