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The Air Car Nears Completion
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 $7,300 and has a top speed of 68mph. About once every 50,000 km you have to change the oil (1 liter of vegetable oil). Initial plans are to produce 3,000 cars per year."
Mexico has been using this tech for several years now, though this is a bit smaller than the taxi vans.
SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
So.. it costs like 5-10$ to fill a single scuba tank. Where do they get their $1.50 figure from? There is no mention of how that figure is arrived at at all.
:/
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.
Contrary to popular belief, coding is not all free blow-jobs and beer. Those things cost MONEY!
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. If you visit their site you can read MDI's press release about their deal with Tata. 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.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
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...
"There are a dozen opinions on a matter until you know the truth. Then there is only one." - CS Lewis (paraprhase)
BTW, the tanks are the real problem. Cheap, light, strong, pick any two. :-)
-Jay-
Compressing air probably involves combustion-engine driven air compressors, so I don't see the real benefit here.
"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.
The real "Libtards" are the Libertarians!
India didn't invent this car. Read to the end of the article and it says, "MDI is a small, family-controlled company located at Carros, near Nice (Southern France) where Guy and Cyril Negre and their technical team have developed the engine technology and the technologically advanced car it powers." That's right, this car was developed in France.
[..] It takes about 9.8 Watts to move one kilogram one meter in one second. [...] 27.4 kW * 12.5 hours = 343 kW-h.
Congratulations! You just calculated how much energy you need to lift the car to an altitude of 250 km (!)
Gasoline won't explode without being mixed with air. It will burn, but it won't go boom. You can flick a lit cigarette into an open bucket of gas if it has sat a while, and put out the cigarette. It sounds weird, but it's true.
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.
I think the original poster meant this 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".
Let's do the math, but starting from different angle. Really cheap electricity is $0.10/kWh, and the fuel station will probably charge a 30% markup at a minimum, for $0.13/kWh. For $3.00, if the air compressor is 100% efficient and there are no resistive losses involved with charging the tank, and you charge it at constant temperature you can store 23kWhr. In reality it would store less because the air would heat up as it compresses, then cool down after you leave the pump. The pressure would drop as it cools, so you'd be paying for pressure that you never get to use. The most fuel efficient cars today are hybrids that get 70mpg under very favorable conditions. Gasoline has 34.6MJ/liter (http://en.wikipedia.org/wiki/Gasoline), so if the Prius is 48% efficient (http://www.uwgb.edu/dutchs/EarthSC102Notes/102Ene rgy.htm) it will take 70mpg / 34.6MJ/l / 48% * 3.785gal /l * 1.6km / mile = 25.5km/MJ . With our cheap power, that comes out to 25.5km/MJ * 0.278 MJ/kWh / $0.13/kWh = 54.6 km/$ , or $5.49/300km . So expecting to travel 300km with only $3.00 worth of fuel would require you to invent a 100% efficient compressed air powertrain, get really cheap power, and double the efficiency (post-engine) of modern cars. Not bloody likely.
We can also calculate the pressure and maximum size of the fuel tank if we remember that PV=nRT and W = integral(P, dV). Solving for constant temperature charging gives W = nRT_initial - lnV |(V_initial - V_final) . Traveling 300km with the above figures requires storing 11.76MJ. I get 24.8m for the maximum tank size that would still be high enough pressure. But that's bigger than the car. A 50 gallon tank is probably about the biggest you could fit in that tiny car, and this would be only 0.187 cubic meter. Such a tiny tank could theoretically store 56MJ. If that is indeed their tank size, then the car might actually work with realistically efficient parts. But from Boyle's law the pressure would be 500atm!
iso = same
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
""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).""
The US is not the worst in emissions per capita. This should be obvious a prior with a few small extremely rich Middle Eastern oil nations.
c ap-environment-co2-emissions-per-capita
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.