The Air Car Nears Completion 750
torok writes "According to an article on Gizmag, Tata, India's largest automotive manufacturer, has developed a car that runs on compressed air. It costs less than $3 USD to fill a tank on which it can run for 200 to 300km. The car will cost about USD $7,300 and has a top speed of 68mph. About once every 50,000 km you have to change the oil (1 liter of vegetable oil). Initial plans are to produce 3,000 cars per year."
Mexico has had this (Score:5, Informative)
Not the only company developing "Air Cars"... (Score:2, Informative)
Lack of good info (Score:5, Informative)
Running a two stage compressor for 3-4 hours will probably cost more than $1.50
And "Zero-pollution"? Can we have some truth in advertising please? Using the car causes pollution, plain and simple. Maybe it's 1/10th or maybe less of a petrol car but at least be honest about it and let us know exactly how much pollution it does cause. It's certainly not 0. Saying so leads to people assiming that this is some kind of crank.
Summary is seriously incorrect. (Score:5, Informative)
You know, I'm starting to get the idea that it really WOULD kill the editors to actually edit something. This is of course proof that the Firehose cannot make up for the failings of idiot editors.
Now, if there were no links in TFA, then torok would have an excuse for not knowing that this vehicle was actually developed by Moteur Developpment International, or MDI [theaircar.com]. If you visit their site you can read MDI's press release about their deal with Tata [theaircar.com]. But in fact not only the technology but the entire vehicle was designed by MDI. Not only have they been using them in Mexico (Mexico City is the most polluted city on the planet) but they've been using them for some years in Spain.
Shame on you torok, and shame on you ScuttleMonkey. The former for falsely attributing the vehicle and technology to the undeserving; the latter for not doing his job and checking the story for validity.
Re:Zero emissions? (Score:1, Informative)
The Developer's Web Site (Score:3, Informative)
Not Vapourware in Australia (Score:2, Informative)
http://www.engineair.com.au/ [engineair.com.au]
I've seen it in operation on a science tech program:
http://www.abc.net.au/tv/newinventors/txt/s107206
It has some immediate potential:
http://www.engineair.com.au/development.htm [engineair.com.au]
and:
http://www.theage.com.au/articles/2004/08/25/1093
Of course there are difficulties associated with deploying a new technology:
http://www.abc.net.au/science/news/stories/s11835
Inaccurate (Score:3, Informative)
I've been following the air car for a while, it sounds like a great idea, the problem is that the engine is still a heat engine, so only about 1/3 of the energy used to compress the gas can be extracted, so even if the gas can be compressed to the same energy density as li-ion cells, you have to carry 3 times as much of the stuff.
Re:I'm impressed (Score:4, Informative)
Take $0.10 per kW-hr. A kg of gasoline has around 42000 kJ, or about 10 kW-hr (1 kW-hr = 3600 kJ) (I'm rounding horribly for simplicity, but it's not going to change the analysis much). A gallon of gasoline has about 2.5 kg of liquid, so that's about 25 kW-hr. Assuming similar efficiencies as gasoline - not unreasonable considering compression of air is typically adiabatic but then stored so you bleed out a lot of energy as heat (insulation to keep that energy would be heavy). So 10 gallons would be about 250 kW-hr. At $0.10 a kW-hr, that means about $25 in electricity. So, to get down to $3 a fill-up, you'd need something that's about 8x the thermal efficiency of gasoline, or something that is quite microscopic so doesn't have much drag. Considering you can't get 8x the efficiency of gasoline (it's already between 20% and 30%), I don't see a fill-up costing $3.
That said, $25 a tank is very comparable to gasoline, so it's probably reasonable.
However, my requirement for alternative fuels is still 400+ miles (note 200-300km from the article is only 124 to 186 miles) on a single "charge", and able to get a complete charge in 5 minutes, for $30 or less, with no nominal increase in vehicle cost.
Other than that, I don't really care what the technology is...
No, I don't think so. (Score:3, Informative)
BTW, the tanks are the real problem. Cheap, light, strong, pick any two. :-)
-Jay-
Re:That far on 3 dolalrs? (Score:3, Informative)
Gasoline engine loses 80% of it's power.
Geo Metro costs approx. $7.50 to go 300km (3.5 gallons @2.15)
I don't know what the efficiency is of electricity, but it is certainly in the realm of possibility that this is efficient enough to cost $3.00/200-300km (if we use 200km it is real reasonable).
I bet you don't pay any tax on compressed air either.
Re:Zero emissions? (Score:4, Informative)
"probably"? You're writing off this entire technology because of a "probably"? News flash: energy can be converted from one form into another and stored in innumerable ways (and with only moderate loss according to efficiency physics and such). i.e. You can compress air using whatever the hell you want. The local hardware store has a compressor that runs from a wall outlet. With enough solar cells you could power that outlet. You could do it up to a point by hooking up a damn bicycle to an air pump for christ sake.
This technology takes one problem and converts it into another problem, namely how do we get compressed air without creating emissions. Pretty much everything we learn from science is based on the idea of converting one problem into another one we can solve.
Re:Lack of good info (Score:1, Informative)
Re:Danger... (Score:5, Informative)
Re:India (Score:5, Informative)
Re:Lack of good info (Score:1, Informative)
Re:Lack of good info (Score:3, Informative)
Actually, most of the time it is just compressed air: ~78% Nitrogen and ~21% Oxygen. Special mixtures such as Nitrox, Heliox and Trimix are used for deep dives, or to extend the time you stay down, but are not recquired for shallow, recreational dives, which is what most people do. Use of special mixtures requires extra training and involves a lot more double-checking and more risks and is not for the casual, "I went to Cancun once!", divers.
The big danger with getting tanks filled is if the shop doesn't properly manage their compressor exhaust. Since they pull in regular air, if the intake is too close to the exhaust you can get a tank with some Carbon Monoxide in it, which is a bad thing. Blacking out on land means you can still breath, even if it is tainted. Do it 50 feet down and you have to hope someone realizes something is wrong before your regulator comes out and you try to breath water.
Diving reference. [uillinois.edu]
Re:I'm impressed (Score:5, Informative)
Congratulations! You just calculated how much energy you need to lift the car to an altitude of 250 km (!)
Re:Lack of good info (Score:2, Informative)
Re:Danger... (Score:5, Informative)
The worst thing I can conceivably see happening with gasoline is the tank being punctured and leaking the gas, which then ignites. Or if you have a nearly empty tank of gas and roll a bunch before an ignition source is exposed to your now well-shook-up gasoline. In both of those cases, though, you'd be really fucked if you were in a fiber-glass car with a glued frame.
Cars don't explode like they do in the movies. Except maybe the Pinto. (A type of car that has an exploding gas tank, named after a bean that gives you gas...)
If you're driving a Pinto, my condolences.
Re:Countdown till said inventor disappears... (Score:3, Informative)
Seriously, how many brilliant inventions have we heard of lately, and how many of those vanish just days after being announced?
In 1874 the Hudson River Tunnel Company was talking up the idea of using compressed air locomotives. Penn Station Lives! [americanheritage.com]
Compressed air locomotives saw significant commercial development and use from 1900 to 1930. The Air Car has been around since at least 1979. Pnematics Options Research Library: air car research since 1979 [aircaraccess.com]
A Korean company demonstrated a hybrid pneumatic-electric car in 2005 Car that runs on compressed air [cnn.com]
Compressed air is generally used when alternative sources of power are too clumsy or too dangerous for the job, not because the CA system (when seen as a whole) is cleaner or more efficient.
Dutch Ovens (Score:3, Informative)
Re:Dutch Ovens (Score:5, Informative)
I think the original poster meant this [wikipedia.org] particular usage of the term "Dutch Oven":
A practical joke involving flatulence underneath a blanket or cover inspired by the mechanics of the "Dutch Oven".
Re:I'm impressed (Score:3, Informative)
Other air cars (Score:1, Informative)
http://www.beyondtomorrow.com.au/stories/ep17/fre
http://www.beyondtomorrow.com.au/stories/ep17/aus
The air tanks are carbon fibre reinforced from memory.
Re:Back to physics class for you (Score:3, Informative)
Yours are also good but your engineering is lacking.
isothermic compression only happens if you insulate the storage medium. at 200+_ atm the temperatures are quite high with isothermic compression. insulating the tank and operating in this temperature region is going to cause all sorts of neat problems, like breaking down the composite matrix that he is building the tanks from.
As a practical matter the compressed air will be near room temperature by the time it is used (if not colder due to pressure bleed off).
I am curious whether the energy density of this is greater than or less than a bank of batteries, but it is an interesting solution to pollution shifted (not free) vehicles.
Back to physics class for you too (Score:3, Informative)
thermal = temperature
isothermal = same temperature
With isothermal expansion and compression, the temperature doesn't change. The process is inefficient to the extent that the temperature does change; so the trick is to keep that from happening.
Here's a quote from http://en.wikipedia.org/wiki/Gas_compressor [wikipedia.org]
""Charles's law says "when a gas is compressed, temperature is raised". There are three possible relationships between temperature and pressure in a volume of gas undergoing compression:
* Isothermal - gas remains at constant temperature throughout the process. In this cycle, internal energy is removed from the system as heat at the same rate that it is added by the mechanical work of compression. Isothermal compression or expansion is favored by a large heat exchanging surface, a small gas volume, or a long time scale (i.e., a small power level). With practical devices, isothermal compression is usually not attainable. For example, even a bicycle tire-pump gets hot during use.
* Adiabatic - In this process there is no heat transfer to or from the system, and all supplied work is added to the internal energy of the gas, resulting in increases of temperature and pressure. Theoretical temperature rise is T2 = T1Rc((k-1)/k)), with T1 and T2 in degrees Rankine or kelvins, and k = ratio of specific heats (approximately 1.4 for air). The rise in air and temperature ratio means compression does not follow a simple pressure to volume ratio. This is less efficient, but quick. Adiabatic compression or expansion is favored by good insulation, a large gas volume, or a short time scale (i.e., a high power level). In practice there will always be a certain amount of heat flow, as to make a perfect adiabatic system would require perfect heat insulation of all parts of a machine.
* Polytropic - This assumes that heat may enter or leave the system, and that input shaft work can appear as both increased pressure (usually useful work) and increased temperature above adiabatic (usually losses due to cycle efficiency). Cycle efficiency is then the ratio of temperature rise at theoretical 100 percent (adiabatic) vs. actual (polytropic).""
Re:How do they come up with the numbers (Score:3, Informative)
300 kilometers might be pushing it (not that I'm an expert here)
OK, some numbers:
based on the GP's 35MJ figure, a 700 bar tank would contain 122.5MJ.
For a range of 300km, that's 408 joules per metre.
Travelling at 100km/hr = 27m/s, 408 joules per metre = 11kW.
This does sound plausible for a lightweight vehicle, on a long distance journey with little stop/starting.
Re:When Americans do that, it's "Outsourcing" (Score:1, Informative)
We know about WWII, but it's worth pointing out that the reason that the French surrendered is because their allies RAN AWAY, leaving the entire German army on their doorstep.
The French surrendered because unlike the English, they had no further to run.
Now, apart from WWII, when else have they thrown in the towel when another (reasonable) nation would not have?
The French had been fighting wars both on their own soil and abroad for more than a thousand years before Columbus was even born.
In fact, the USA wouldn't even exist had the French not helped them out.
Re:Electric (Score:1, Informative)
Re:India (Score:2, Informative)
Calling people dicks unnecessarily in polite discussion is uncalled for. Ad homonym attacks are counterproductive and rightfully make you look like an asshole and instantly lower your position in any debate. First of all from the discussion it is clear the gp was referring to noxious emissions that cause difficulty breathing (though erroneously indicating global warming emissions at the end where US has the lead in CO2 pollution emission). NO2 emissions cause great difficulty in breathing and Mexico has the WORLDS HIGHEST CONCENTRATIONS of this in urban areas, where U.S. comes in 45th place. And nitrogen oxides per capita have U.S. as third. Also, U.S. is 38th in SO2 pollution. The point is there are different types of pollution and to say overall when using generic term of "polluter" is clearly wrong.
Compressed air is the most expensive power source (Score:3, Informative)
After working in factories for 15 years, every mechanical engineer I've talked to tells me that plant compressed air is the worst way to use power.
It's the most expensive (in terms of power) to make, and to transmit (what sort of baby-poop do you use when pulling black iron pipe?).
The reason they use it is that the equipment that uses it is cheap to build and maintain compared to its electrical brothers.
Count the number of parts in an air cylinder and the number of parts in a linear actuator (ball screw or linear motor) of the same force and stroke.
If someone came up with a way to make compressed air that cheaply, they'd make a lot more money by selling the tech to Toyota than to Toyota's customers.
Re:India (Score:5, Informative)
http://www.nationmaster.com/graph/env_co2_emi_per
If you look at SO2 and NOx emissions per populated area, the USA is MUCH MUCH better. Our CO2 emissions comes with less SO2 and NOx than almost any other nation! In short, yes we burn a lot of fossil fuels, but we burn it cleaner than anyone.
More to the point, fossil fuel usage, per capita, has been steady in the USA since 1976. We are not the primary source of change that is altering the planet for the last 30 years. We were already there 30 years ago!
Change is heaviest in countries that are industrializing like Mexico, India, and China. Obviously, addressing the scope of the problem would require major changes in all nations. Currently there does not seem to be ANY HOPE of preventing further increases in greenhouse gases as there is nothing on the table to prevent nations that are industrializing from continuing on that track. Any changes that could be made in the USA, Canada, and Western Europe (and Oz and Japan) would pale in comparison to the large increases coming from China and India. And short-sighted, when you consider that capping CO2 emissions will force a quarter-after-quarter recession on all involved nations. And ain't that a pretty picture to consider?
I, for one, welcome our new farting car overlords. They actually could help.
Polymerized vegetable oil (Score:1, Informative)
Otherwise I would have taken it seriously, however using vegetable oil as a lubricant destroys any credibility the product might have had.
P.S. The article is much more readable in lynx, the text loads almost immediately, even on dial-up, and the ad spam is completely avoided.
Re:why? (Score:3, Informative)
Similar to paintball tanks - about 4000 PSI. They rate it in 'bar' and IIRC it was 300 or something like that. I read about this on the discovery channel recently, went to the site and promptly forgot about it when I realized it would be the same technology as the paintball air tanks.
You're right -- the compressor to compress air to 4000 PSI is non-trivial. I toyed with getting my son one so he could fill his paintball tanks and maybe we could run a field. He quickly lost interest in paintballing, however.