Vermes
Advanced Member level 4
Nowadays, when most people are concerned about the environment protection and economic, you usually look for devices which are not only environmentally friendly, but also not expensive solutions. Cars powered by compressed air are very good example of such devices. You can find a lot of information on air-powered cars on the Internet, including theoretical specifications of such vehicles and optimistic estimations that in near future those cars would be easy to buy. But, in spite of it all, air-powered cars are still only a new idea rarely used in the real life and we are still dependent on petroleum, prices of which continue to rise.
MDI is a French company, which is one of the world's pioneers of air technology. It works on prototype constructions of air-powered vehicles since the very beginning of the 90s. Cars produced by that company can be watched moving on the Internet videos, but unfortunately, although MDI keeps ensuring that they will be soon produced for sale, they still cannot be found on the steets.
Is the construction of MDI's prototype so complicated? Not really. The main load-bearing element consists of an aluminum frame. Lightweight body made of plastic is mounted on the frame. Special containers made of polymers and produced by Boeing, are installed in the floor of the vehicle. Construction of the motor also needs to be much more lightweight than in normal cars, powered by petrol. What more, it does not require cooling, because temperature of expanding air is low enough to provide efficient cooling of the motor. Furthermore, this feature of air-powered cars can be also used for air conditioning in the cab. Both motor and alternator act double roles. Alternator can be changed into an electric engine when the car is parked. That electric engine can drive the motor which in that particular situation works as a compressor. You can load the container when the external supply is connected. MDI estimates that their newest vehicle is able to make a distance of more than 200 km using only a single container with capacity of 300l.
MDI motor produced for vehicle called AirPod
Unfortunately, producers are not honest when they talk about air-powered cars. The density of mechanical energy stored in the container is not enough and cannot be compared with a traditional, petrol-powered car. Steel tanks can be replaced with composite counterparts with better parameters, but the results will still be not satisfactory. What more, compressing air is not very effective, as the process of compression allows you to save only 1/8 of the energy required for producing it. Constructions of pneumatic cars have to be as lightweight as possible due to quite low power of the motor. Such not powerful motors can never have better dynamic and power steering supply than traditional ones. Another disadvantage is that required for such cars lightweight body will never ensure the adequate level of protection. And the last one – vehicle which is powered by compressed air has itself a lot of „ excess cold”, so how it could heat the cab when it is cold outside?
License to use the patents of MDI was bought by the Indian company TATA. It is ensured that first models of the vehicles should be available in dealership showrooms in 2012. Although most of technologies were based on MDI solutions, cars produced by TATA probably will have an opportunity to be driven using petrol. There are two possible options of those vehicles. First one is that a car is equipped with an additional motor to drive an additional compressor. Another option is a combination of air and internal combustion engine. Additionally, burned petrol would improve the thermal conditions of the engine.
AirPod presented by MDI in 2011
Air-powered vehicles produce no gas which is harmful to the environment, including carbon dioxide (except those contained in the copressed air). But remember, that when you want to compress air, you need to use electric energy. Power stations in most cases burn coal, what increases emission of carbon dioxide. The most optimum solution would be to create more renewable energy sources, however, it is hard to estimate how long it will take.
There is another solution – replace air with hydrogen. It is not impossible, but requires improving hydrogen collecting and storage technology. Thus, more efficient source of energy could be found. Hydrogen installations could possibly be assembled in traditional cars with internal combustion engine.
The technology is used in practice. Every car repair shop uses pneumatic tools, which are equipped with an engine powered by compressed air. Pneumatic vehicle are used in mines, because any other power could cause the risk of fire. In such cases the advantages of using such energy source are greater than the cost of compressed air. Still the idea of compressed air-powered car is not bad, but now it is neither practical nor cost-effective. Surely it will not be a competition for traditional cars with a combustion engine.
MDI is a French company, which is one of the world's pioneers of air technology. It works on prototype constructions of air-powered vehicles since the very beginning of the 90s. Cars produced by that company can be watched moving on the Internet videos, but unfortunately, although MDI keeps ensuring that they will be soon produced for sale, they still cannot be found on the steets.
Is the construction of MDI's prototype so complicated? Not really. The main load-bearing element consists of an aluminum frame. Lightweight body made of plastic is mounted on the frame. Special containers made of polymers and produced by Boeing, are installed in the floor of the vehicle. Construction of the motor also needs to be much more lightweight than in normal cars, powered by petrol. What more, it does not require cooling, because temperature of expanding air is low enough to provide efficient cooling of the motor. Furthermore, this feature of air-powered cars can be also used for air conditioning in the cab. Both motor and alternator act double roles. Alternator can be changed into an electric engine when the car is parked. That electric engine can drive the motor which in that particular situation works as a compressor. You can load the container when the external supply is connected. MDI estimates that their newest vehicle is able to make a distance of more than 200 km using only a single container with capacity of 300l.
MDI motor produced for vehicle called AirPod
Unfortunately, producers are not honest when they talk about air-powered cars. The density of mechanical energy stored in the container is not enough and cannot be compared with a traditional, petrol-powered car. Steel tanks can be replaced with composite counterparts with better parameters, but the results will still be not satisfactory. What more, compressing air is not very effective, as the process of compression allows you to save only 1/8 of the energy required for producing it. Constructions of pneumatic cars have to be as lightweight as possible due to quite low power of the motor. Such not powerful motors can never have better dynamic and power steering supply than traditional ones. Another disadvantage is that required for such cars lightweight body will never ensure the adequate level of protection. And the last one – vehicle which is powered by compressed air has itself a lot of „ excess cold”, so how it could heat the cab when it is cold outside?
License to use the patents of MDI was bought by the Indian company TATA. It is ensured that first models of the vehicles should be available in dealership showrooms in 2012. Although most of technologies were based on MDI solutions, cars produced by TATA probably will have an opportunity to be driven using petrol. There are two possible options of those vehicles. First one is that a car is equipped with an additional motor to drive an additional compressor. Another option is a combination of air and internal combustion engine. Additionally, burned petrol would improve the thermal conditions of the engine.
AirPod presented by MDI in 2011
Air-powered vehicles produce no gas which is harmful to the environment, including carbon dioxide (except those contained in the copressed air). But remember, that when you want to compress air, you need to use electric energy. Power stations in most cases burn coal, what increases emission of carbon dioxide. The most optimum solution would be to create more renewable energy sources, however, it is hard to estimate how long it will take.
There is another solution – replace air with hydrogen. It is not impossible, but requires improving hydrogen collecting and storage technology. Thus, more efficient source of energy could be found. Hydrogen installations could possibly be assembled in traditional cars with internal combustion engine.
The technology is used in practice. Every car repair shop uses pneumatic tools, which are equipped with an engine powered by compressed air. Pneumatic vehicle are used in mines, because any other power could cause the risk of fire. In such cases the advantages of using such energy source are greater than the cost of compressed air. Still the idea of compressed air-powered car is not bad, but now it is neither practical nor cost-effective. Surely it will not be a competition for traditional cars with a combustion engine.
