Have you been to the gas station this week? Considering that we live in a very mobile society, it's probably safe to assume that you have. While pumping gas, you've undoubtedly noticed how much the price of gas has soared in recent years. Gasoline which has been the main source of fuel for the history of cars, is becoming more and more expensive and impractical (especially from an environmental standpoint). These factors are leading car manufacturers to develop cars fueled by alternative energies. Two hybrid cars took to the road in 2000, and in three or four years fuel-cell-powered cars will roll onto the world's highways.
While gasoline prices in the United States have not yet reached their highest point ($2.66/gallon in 1980), they have climbed steeply in the past two years. In 1999, prices rose by 30 percent, and from December 1999 to October 2000, prices rose an additional 20 percent, according to the U.S. Bureau of Labor Statistics. In Europe, prices are even higher, costing more than $4 in countries like England and the Netherlands. But cost is not the only problem with using gasoline as our primary fuel. It is also damaging to the environment, and since it is not a renewable resource, it will eventually run out. One possible alternative is the air-powered car.
Air powered cars runs on compressed air instead of gasoline. This car is powered by a two cylinder compressed engine. This engine can run either on compressed air alone or act as an IC engine. Compressed air is stored in glass or fiber tanks at a pressure of 4351 psi.
Within the next two years, you could see the first air-powered vehicle motoring through your town. Most likely, it will be the e.Volution car that is being built by Zero Pollution Motors.
The cars have generated a lot of interest in recent years, and the Mexican government has already signed a deal to buy 40,000 e.Volutions to replace gasoline- and diesel-powered taxis in the heavily polluted Mexico City.
2. VEHICLE PARTS
Compressed air tanks
One of the most frequently asked questions is about the safety of the compressed air storage tanks. These tanks hold 90 cubic meters of air compressed to 300 bars. Many people ask whether this system is dangerous in case of an accident and if there is a risk of explosion. The answer is NO. Why? Because these are the same tanks used to carry the liquid gas used by buses for public transport. The tanks enjoy the same technology developed to contain natural gas. They are designed and officially approved to carry an explosive product: methane gas.
In the case of a major accident, where the tanks are ruptured, they would not explode since they are not metal. Instead they would crack, as they are made of carbon fiber. An elongated crack would appear in the tank, without exploding, and the air would simply escape, producing a loud but harmless noise. Of course, since this technology is licensed to transport an inflammable and explosive gas (Natural gas), it is perfectly capable inoffensive and non-flammable air.
It is fitting, therefore, that MDI has reached an agreement with the European leader in aerospace technology Airbus Industries for the manufacture of the compressed air storage tanks. With a remote supervision arrangement, Airbus Industries oversees the making of the storage tanks at each MDI factory. The coiled carbon fibre technology used in the construction of the tanks is complex and requires a substantial quality control process which the multinational company, home of the Airbus aircraft, will provide for our vehicles.
Brake power recovery
The MDI vehicles will be equipped with a range of modern systems. For example, one mechanism stops the engine when the car is stationary (at traffic lights, junctions etc). Another interesting feature is the pneumatic system which recovers about 13% of the power used.
The MDI car body is built with fibre and injected foam, as are most of the cars on the market today. This technology has two main advantages: cost and weight. Nowadays the use of sheet steel for car bodies is only because of cost - it is cheaper to serially produce sheet steel bodies than fibre ones. However, fibre is safer (it doesnâ„¢t cut like steel), is easier to repair (it is glued), doesnâ„¢t rust etc. MDI is currently looking into using hemp fibre to replace fibre-glass, and natural varnishes, to produce 100% non-contaminating bodywork.
The Air Filter
The MDI engine works with both air taken from the atmosphere and air pre-compressed in tanks. Air is compressed by the on-board compressor or at service stations equipped with a high-pressure compressor.
Before compression, the air must be filtered to get rid of any impurities that could damage the engine. Carbon filters are used to eliminate dirt, dust, humidity and other particles, which unfortunately, are found in the air in our cities.
This represents a true revolution in automobiles - it is the first time that a car has produced minus pollution, i.e. it eliminates and reduces existing pollution rather than emitting dirt and harmful gases. The exhaust pipe on the MDI cars produces clean air, which is cold on exit (between -15Ã‚Âº and 0Ã‚Âº) and is harmless to human life. With this system the air that comes out of the car is cleaner than the air that went in.
Based on its experience in aeronautics, MDI has put together highly resistant, yet light, chasses, aluminium rods glued together. Using rods enables us to build a more shock-resistant chassis than regular chasses. Additionally, the rods are glued in the same way as aircraft, allowing quick assembly and a more secure join than with welding. This system helps to reduce manufacture time.
Guy NÃƒÂ¨gre, inventor of the MDI Air Car, acquired the patent for an interesting invention for installing electrics in a vehicle. Using a radio transmission system, each electrical component receives signals with a microcontroller. Thus only one cable is needed for the whole car. So, instead of wiring each component (headlights, dashboard lights, lights inside the car, etc), one cable connects all electrical parts in the car. The most obvious advantages are the ease of installation and repair and the removal of the approximately 22 kg of wires no longer necessary. Whats more, the entire system becomes an anti-theft alarm as soon as the key is removed from the car.
3. TECHNOLOGY DESCRIPTION
The following is the technology description of the actual functionality of the motor. A more detailed explanation can be found in U.S. patent no: 6,334,435
1. The first piston takes in ambient air and compresses it to approximately 300 psi and 200*f in the compression chamber during the first cycle of the engine.
2. When the piston pause, a small amount of compressed air from the tanks is released into the expansion chamber to create a low pressured, low temperature volume of about 140psi
3. Shortly before the valve to the exhaust cylinder is opened, a high-speed shutter connects the compression and expansion chambers. The sudden pressure and temperature difference between the low chambers creates pressure waves in the expansion chamber, thereby producing work in the exhaust chamber that drives the piston to power the engine.
The air tanks for storing the compressed air are localized underneath the vehicle. They are constructed of reinforced carbon fiber with a thermoplastic liner. Each tank can hold 3,180 ft3 of air at a pressure of up to 4,300 psi. When connected to a special compressor station, the tanks can be recharged within 3-4 minutes. They can also be recharged using the on-board compressor 3-4 hours after connecting to a standard power outlet.
3.1. TECHNOLOGY OVERVIEW
These new vehicles incorporate various innovative and novel systems such as storing energy in the form of compressed air, using new materials such as fiberglass to build the car and vegetable oil for the motor lubrication.
Numerous innovations have been integrated in the engine design. As an example, there is a patented system of articulated conrods that allow the piston to pause at top dead center. The following graph indicates this movement of the piston in relation to the driving shaft rotation.
The car engine runs on compressed air and incorporates the three laws of thermodynamics.
1. The first law states that energy can neither be destroyed nor be wasted.
2. The second law describes the disorder within substances.
3. The third law defines that only in crystals at 0o k, there is absolute disorder.
The car incorporates these laws of thermodynamics in the following way. First, the pressure that is created within on-board tanks during compression is in direct proportion to the energy that has been stored in it. This process is equivalent to the energy stored in a wire spring when it is compressed.
Furthermore, thermal energy is dissipating from the system, thereby lowering the temperature of a compressed gas volume that expands. This process is equivalent to harnessing energy that has been stored.
In turning the shaft, shock waves similar to supersonic waves are created when two gases with very different characteristics are mixed together in a certain fashion. All these effects result in a high-powered air technology.
Air powered cars run on compressed air instead of gasoline. Since the car is working on air there is no pollution. A two cylinder, compressed air engine, powers the car. The engine can run either on compressed air alone or act as an internal combustion engine. Compressed air is stored in fiber or glass fiber tanks at a pressure of 4351 pounds per square inch. The air is fed through an air injector to the engine and flows into a small chamber, which expands the air. The air pushing down on the piston moves the crankshaft, which gives the vehicle power.
This car is also working on a hybrid version of their engine that can run on hybrid version of their engine that can run on traditional fuel in combination with air. The change of energy source is controlled electronically. When the car is moving at speeds below 60kph,it runs on air. At higher speeds, it runs on a fuel such as gasoline diesel or natural gas.
Air tanks fixed to the underside of the vehicle can hold about 79 gallons (300 litres) of air. This compressed air can fuel the car upto 200km at a top speed of 96.5kph.When the tank nears empty it can be refilled at the nearest air pump. The car motors require a small amount of oil about 0.8 litres worth that have to change just every 50,000km.
4.1 GEAR BOX
Gear changes are automatic, powered by an electronic system device. A computer which controls the speed of the car is effectively continuously changing gears. The latest of many previous versions, this gearbox achieves the objective of seamless changes and minimal energy consumption.
4.2 DISTRIBUTION AND VALVES
To ensure smooth running and to optimize energy efficiency, engines use a simple electromagnetic distribution system which controls the flow of air into the engine. This system runs on very little energy and alters neither the valve phase nor its rise.
The moto-alternator connects the engine to the gearbox. It has many functions:
Ã‚Â· It supports the vehicles motor to allow the tanks to be refilled.
Ã‚Â· As an alternator it produces brake power
It starts the vehicle and provides extra power when necessary.
BASIC PRINCIPLES OF COMPRESSED AIR TECHNOLOGY ENGINE
It uses an innovative system to control the movement of the second-generation pistons and one single crankshaft. The pistons work in two stages and one intermediate stage of compression and expansion.
The engine has four stage pistons that are 8 compression and or expansion chambers. They have two functions:
1. To compress ambient air
2. To make successive expansions thereby approaching isothermic expansion.
THE DUAL ENERGY SYSTEM
The engine can be equipped with and run on dual engines. Fossil fuels and compressed air and incorporate a reheating mechanism between the storage tank and the engine. This mechanism allows the engine to run exclusively on fossil fuel, which permits compatible autonomy on the road. While the car is running on the fossil fuel, the compressor air tanks. The control system maintains a zero pollution emission in the city at speeds upto 60 km per hour.
THE AIR FILTER
The air compressed engine works on with both air taken from the atmosphere and air pre compressed in tanks. Air is compressed by the on board compressor or at service stations equipped with a high-pressure compressor.
Before compression the air must be filtered to get rid of any impurities that could damage the engine. Carbon filters are used to eliminate dirt, dust, humidity and abundant abrasive particles that unfortunately exist in the air from our cities.
This system eliminates and reduces existing pollution rather than emitting dirt and harmful gases. The exhaust pipe on the air-powered cars produces clean air which is cold on exit (between 15o and 0o) and is harmless to human life. With this system the air that comes out of the car is cleaner than the air that went in.
5. CRYOGENIC HEAT ENGINE
Another version of an air-powered car is being developed by researchers at the University of Washington using the concept of a steam engine, except there is no combustion. The Washington researchers use liquid nitrogen as the propellant for their LN2000 prototype air car. The researchers decided to use nitrogen because of its abundance in the atmosphere -- nitrogen makes up about 78 percent of the Earth's atmosphere -- and the availability of liquid nitrogen. There are five components to the LN2000 engine:
ÃƒËœ A 24-gallon stainless steel tank.
ÃƒËœ A pump that moves the liquid nitrogen to the economizer.
ÃƒËœ An economizer that heats the liquid nitrogen with leftover exhaust heat.
ÃƒËœ A heat exchanger that boils the liquid nitrogen, creating a high pressure gas.
ÃƒËœ An expander, which converts nitrogen's energy into usable power.
The liquid nitrogen, stored at -320 degrees Fahrenheit (-196 degrees Celsius), is vaporized by the heat exchanger. The heat exchanger is the heart of the LN2000's cryogenic engine, which gets its name from the extremely cold temperature at which the liquid nitrogen is stored. Air moving around the vehicle is used to heat the liquid nitrogen to a boil. Once the liquid nitrogen boils, it turns to gas in the same way that heated water forms steam in a steam engine.
Nitrogen gas formed in the heat exchanger expands to about 700 times the volume of its liquid form. This highly pressurized gas is then fed to the expander, where the force of the nitrogen gas is converted into mechanical power by pushing on the engine's pistons. The only exhaust is nitrogen, and since nitrogen is a major part of the atmosphere, the car gives off little pollution. However, the cars may not reduce pollution as much as you think. While no pollution exits the car, the pollution may be shifted to another location. As with the e.Volution car, the LN2000 requires electricity to compress the air. That use of electricity means there is some amount of pollution produced somewhere else. Some of the leftover heat in the engine's exhaust is cycled back through the engine to the economizer, which preheats the nitrogen before it enters the heat exchanger, increasing efficiency. Two fans at the rear of the vehicle draw in air through the heat exchanger to enhance the transfer of heat to the liquid nitrogen.
The Washington researchers have developed a crude prototype of their car, using a converted 1984 Grumman-Olson Kubvan mail truck. The truck has a radial five-cylinder that produces 15 horsepower with the liquid nitrogen fuel. It also features a five-speed manual transmission. Currently, the vehicle is able to go only about two miles (3.2 km) on a full tank of liquid nitrogen, and its top speed is only 22 mph (35.4 kph). However, because a liquid nitrogen-propelled car will be lighter, the researchers think that a 60-gallon (227 liters) tank will give the LN2000 a potential range of about 200 miles (321.8 km). With gas prices soaring, as they have over the past two years, it might not be long before many motorists turn to vehicles powered by alternative fuels. Although air-powered vehicles are still behind their gasoline counterparts when it comes to power and performance, they cost less to operate and are arguably more environmentally friendly, which makes them attractive as the future of highway transportation.
6. PRODUCTION LICENCE FOR MDI'S CAR
A production license for MDI's (Moteur Development International) compressed-air vehicles has recently been signed in Nice, for markets in Colombia, Peru, Ecuador and Panama. The signatory, MDI Andina S.A is a group of business entities from the Columbian private and public sector.
After a thorough examination of the technical and financial aspects of MDI's business, the new associates travelled to Spain to meet MDI's existing licensees. Representatives of MDI Andina S.A. met official representatives of MDI management in Barcelona to negotiate the contract, and then travelled to France to sign the agreement.
With this additional sale there are now 50 fabrication and distribution licenses signed in the world, from a total of 400 available. Some of the countries that have signed agreement include France, Germany, Spain, Portugal, Italy, New Zealand, Israel, South Africa, etc.
As fees for production rights are the only source of financing for the inventor, Mr. Guy NÃƒÂ¨gre, this new contract, worth almost 10 million Euros, is another major step in bringing MDI's Zero Pollution car closer to production.
The question that is most frequently asked is "When will these cars be on the streets? Although a number dates have been released to the media in the past, the programme required some more time to complete. Developing and productionising automobiles is at best a complex, expensive and time-consuming exercise. Guy Negre and his team of dedicated engineers have effectively "reinvented the wheel" within the last 5 years and with the development and introduction of all of this groundbreaking and "new" technology, some delays were inevitable.
Starting factory production of cars that are based on a major technological advance is not easy, and has been made still harder by lack of external financing. So far, the institutions MDI has presented this project to were unprepared to invest in the initial phase of development, while showing great interest in doing so once a car was on the road. Delay in developing this technology has resulted largely from lack of public investment, which has compelled MDI to turn to private investors.
Despite this, the project has made considerable commercial and technological progress. The technology has been shown in London, with the support of the Department of the Environment, and in Sao Paulo, to an audience of over 600. Negotiations are now taking place with investors from all five continents. The first production plant in France is now complete and Guy NÃƒÂ¨gre's latest model, the MultiCAT's, applies the technology in a new direction: commercial and public service vehicles for public and freight transportation.
NEW MODELS, NEW APPLICATIONS:
The MiniCAT's prototype is featured in the latest edition of the 'Salon Mondial de l'Automobile Paris 2002'. This model is as ecologically sound as its predecessors and has equally low fuel consumption; one tank of air is enough for 200 km, at a cost of only 2 Euro. Like its "sister" vehicles, the MiniCAT's emits only clean air at a temperature of -20Ã‚ÂºC. A main innovation is that with 2.65 meters in length, and with a three seat configuration (the driver is in the center) the boot is as capacious as a conventional family saloon.
Guy NÃƒÂ¨gre has also designed a dual-energy vehicle for longer distances, which works on compressed air in the city, and air/petrol on motorways. This vehicle (the RoadCAT's) can travel more than 2000 km on 100 m3 of air and 50 litres of petrol, so can be used for long journeys and is not an exclusively urban vehicle. Other applications of the technology include power generation, compressing air as a means of storing energy, and powering boats.
MDI also presented the MultiCAT's concept of a zero pollution urban transportation system which incorporates several important economic advantages. Consisting of a Driver module and up to 4 transport modules, (as in a train with tyres) it has been developed with a view to transporting up to 135 people at a cost of only 2.5 Euros for each 100 km per module, which could allow local and/or national governments to offer practically free urban transport to its citizens. At the moment the sale of the first license to manufacture the MultiCAT's for the Spanish and Portuguese market is in an advanced stage of negotiation with a group of investors consisting of the MDI license holders for Spain and other companies involved in the transport and energy sectors of those countries.
7. COMPARISON WITH COMPETITION
8. FREQUENTLY ASKED QUESTIONS
How does the air tanks work and are there any issues with their safety?
One of the most frequently asked questions regards the safety of the air tanks, which store 90m3 of air at 300 bars of pressure. Many people ask whether this system is dangerous in case of an accident, and whether there is an explosion risk involved. The answer is NO. Why? Because the tanks are the ones already used to carry liquefied gases on some urban buses, and therefore make use of the technology that is already used to move buses on natural gas. That means that the tanks are prepared and certified to carry an explosive product: methane gas.
In the case of an accident, with air tank breakage, there would be no explosion or shattering, now that the tanks are not metallic. Due to the fact that they are made of glass fibre the tanks would crack longitudinally, and the air would escape, causing a strong buzzing sound with no dangerous factor. It is clear that if this technology has been tested and prepared to carry an inflammable and explosive gas, it can also be used to carry air.
A final matter with reference to the air tanks is the improvement that MDI contributed to the original structure. In order to avoid the so-called 'rocket effect', this means to avoid the air escaping through one of the tank's extremities causing a pressure leak that could move the car, MDI made a small but important change in the design. The valve on the buses' tanks are placed on one of the extremities. MDI has placed the valve in the middle of the tank reducing the 'rocket effect' to a minimum.
It is said to have a 90m3 tank. That is impossible, for it would take up the space of four lorries. There must be a mistake. Yes, there is a mistake. The four tanks have a capacity of 90 litres, and they store 90m3 of air at a pressure of 300 bars.
You refer to an air tank at 200 pressure bars that can be recharged at home with a domestic compressor. With the ones I know about, not only is it impossible, but also it would be dangerous.
The pressure is of 300 bars, not 200. It is not referring to a conventional compressor to refill the tanks. The MDI car has a small compressor designed to fully refill the tanks in 3 to 4 hours.
Which materials are used to produce the body?
The car bodies of the MDI vehicles are made of glass fibre with injected foam, such as many other cars that are on the market nowadays. This technology brings in two main advantages: lower cost and less weight.
What is the weight capacity of the car?
It can carry 450kg of bulk weight, or 4 passengers and the driver.
Is the car noisy?
No, its sound is lower than a normal car's, now that neither explosion nor combustion takes place in the engine.
What is its maximum range?
The range is dependent on the speed. At 50 km/p/h the range is over 300 km. At 100 kmh it is reduced to one third of that. In an urban environment the car can run for upto 10 hours.
What does the fuel cost?
Around $2 to fill up the air tanks.
How long does the refilling of the tanks take?
In an air-refilling station, it takes between 3 and 4 minutes. At home, with a 220V plug, it takes 3 and half hours.
How does the electrical system works?
Guy Negre, the inventor of the MDI engine, acquired the patent of an interesting invention for the electrical installation of the vehicle. It is a system based on the radio emission picked up by micro controllers installed in each one of the electrical devices of the car, which allows there to be one sole cable for the whole car. That is to say, that instead of using one cable for each device (lights, interior car lights, indicators, etc), it uses one cable for the whole car. The two obvious advantages are the simplicity of installation and repairs of the system, and the reduction of weight by 22kg.
What kind of filter is built in, and how does it work?
The MDI engine works with air taken from the atmosphere and pressurized air in the tanks. The air is compressed by the onboard compressor that is incorporated in each car or in an air-refilling station equipped with a high pressure compressor.
In order for the air to be pressurized, it must be filtered previously, to remove all possible impurities that could damage the compressor. Carboni type filters are used to remove dirt, dust and abundant abrasive particles that unfortunately exist in the air of our cities.
This factor is truly revolutionary in the automotive world, for the first time an engine produces negative contamination, in other words it eliminates and reduces already existent pollution rather than releasing dirt and burnt gases.
The exhaust pipe of the MDI vehicle expels clean air, that comes out fresh (between â€œ30 Ã‚ÂºC and 0Ã‚ÂºC) and does not cause disruptions to any form of life. Thanks to this system, the air leaves the vehicle cleaner than it entered.
The engine does not take dirty air and miraculously restore purified air. It expels clean air, I guess with a small amount of oil, and it leaves a dirty filter. Yes. In the same way as major industries are forced to use filters in order to avoid polluting, the compressor filters the air, and later these are recycled and the filters decontaminated. There is no magic or miracles.
The exhaust gases are used to cool the car. But, how does the heating work?
The exhaust gases are not as we generally understand them to be as in the common vehicle. What leaves the vehicle is cool air. The heating works using the energy produced by the considerable temperature difference between the head of the piston at 400Ã‚ÂºC and the cold air expelled between 0Ã‚ÂºC and -30Ã‚ÂºC. When a new vehicle is made, it is shown to the media and then to the ordinary citizens.
Although the engine does not expel contaminating gases, the electric energy needed to make the commediaor work has been produced (most probably) throughout some form of contamination.
You are right. But I doubt you have reached the end of the reasoning. The matter is briefly outlined: With regards to pollution: the MDI engine allows "two displacements and one optimization".
Ã‚Â· The first displacement is geographical: the car is urban, and with it we will stop polluting the city centres now that there is NO emission of contaminating gases. It is important to remember that 80% of car displacements are done in urban centres, where precisely the majority of the population lives.
Ã‚Â· The second displacement is with regards to the responsibility of the pollution. The car runs on air, but this air is pressurized previously by a compressor that uses electricity. At the same time this electricity is produced by the State, thanks to hydraulic energy of rivers, thermic plants that burn petrol, nuclear energy, solar energy and wind energy. If the general citizen decides to use a car that does not expel any form of pollution, it is not in his/her responsibility to determine the source of the energy production. In each country the matter is different. In Spain, the majority of electricity is produced by burning petrol or nuclear sources. That is to say that most of the energy that the car uses is polluting, the rest is clean. In other countries, these figures are the opposite. On the other hand, MDI has patents to install systems of production of compressed air by using the currents of rivers. The cars that use this method will be 100% non-contaminating. In certain provinces, such as Navarra, electricity is nearly 'clean' of pollution, thanks to the use of wind power; the same occurs in areas where wind forms are present, like the Costa del Sol.
Ã‚Â· The optimization that the engine brings is simple: it is much more polluting to burn a bit of petrol in each one of the cars in Spain than to produce this energy massively in industrial plants and use its power throughout compressed air. This system is an evident optimization now that it benefits the vehicle's global energetic profitability.
Environmentally speaking, the restore of a gas to the atmosphere (even if it is air), at a very different temperature (between 0Ã‚ÂºC and -30Ã‚ÂºC) means an impact on the atmosphere.
Completely true in theory, but in practice it works the other way round: ALL human systems produce great amounts of heat that had not been previewed and that affect the planetary ecosystem since tens of years ago. Releasing small amounts of cool air does not assume any risks. What's more: in order to compress the air some heat is released in the process...
When will the approval process be finalized?
Towards the end of the year 2002/early 2003.
When will the first cars produced?
In France the first car series are to be produced towards late December 2002 and the first cars will be used to assist float orders.
When will the first cars on the market?
Maybe in a simultaneous way around the same date as above. It all depends on the order of construction of factories throughout the world.
What is the average estimate price?
Between 8.000 and 10.000 $ for the basic vehicle: taxi, van, pick-up truck or "family car".
In this seminars I have presented the working of air powered cars. Air powered cars is a realization of latest technology in automobile field. It eliminates the use of non-renewable fuels like gasoline, diesel petrol etc, and Thereby preventing pollution caused by millions of automobiles all over the world. This could be the future of automobiles and step to a healthier environment.