The future is what one starts building from the present. Having said that, in the case of fossils fuels, the future remains bleak if not worked upon it to save it or use other resources other than non-renewable ones. Fossil fuels over the last century brought about an era of growth, but they are also fast losing their luster because of their side effects such as pollution and thus being a cause for global warming. We humans being the intuitive and inventive species, desire to save some of this precious fossil fuels for future generations. Hence a whole lot of inventions have been ,since this need for change has been seen. One of the very efficient inventions in the recent times being the pneumatic engines.
The word Pneumatics is a term associated with study and application of pressurized gas to produce mechanical motion. So how is a pneumatic engine different from the regular engine? Well, for beginners, the pneumatic engine operates on the principle that free air will fill any given space, the engine here works on a similar principle as that of a steam engine. instead of steam it employs air by compressing air into a small space it can help in storing energy (i.e. potential energy). When the gas is expands , the energy is releases to do work (i.e. potential energy is converted to kinetic energy which will be used for doing given work)thus this energy can be utilized for running an engine.
Since here the engine relates to using air as an energy source ,there needs to be a special design .when the pneumatic engine is used in a car (an AIR CAR specifically) .The fuel (i.e. compressed air) is stored in a carbon fiber composite storage cylinder. The air from this cylinder is passed into the inlet of the engine where the gas expands as well as heated so that increase in its volume causes the engine to run faster. In the process of expansion air is expanded into factors of three or five then is ejected on top of small pistons through nozzles, due to the pressure applied by the air on piston heads the crank is turned. This process can build up a speed of 56 km/h.
The air is compressed by using an external compressor to compress the air to a very high extent (about 300 bars) and is stored in a carbon fiber storage tank, which is light in weight and is used for safety purpose. The carbon fibers tanks cracks releasing the gas into the atmosphere and not explode on an impact. If any other material is used such as a metal cylinder is used then on an impact the large pressure difference between the inner wall and outer wall of the cylinder (the similar principle of why a balloon bursts when pricked with a pin).
This engine exhaust is nothing but air, hence is non-polluting. As the compressed air from the tank expands the temperature of the gas decreases as the kinetic energy of the gas is lost in moving the piston head, the low temperature gas can be used as air conditioner for the air car.(Thus reducing your further need of polluting the earth with additional emission of chlorofluorocarbons)
It’s all but conclusive that the usage of such engines has a list of advantages .Firstly there is no pollution, as compressed air is the input for engine and air is the gas released in the exhaust. This is one main trump card over the usage of normal fuel engines. Such pneumatic engines are also highly efficient, thus they produce more mileage. Since they employ carbon fiber storage cylinders, they reduce the weight of the vehicle.
The only downside of usage of such engines is that pollution is caused while compressing the air, but this can be reduced by using renewable source of energy for production of electricity which shall be used for compression of air. Also the non-availability of Re-fueling stations, for filling the large carbon fiber tanks might be of some inconvenience, as these are still alternative ways of a better tomorrow.