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The wheel was invented 5000 years ago and many considered it to be the most invention. Adding wheels to carriages and other land vehicles made it possible to transport passengers and goods to different places.
Carl Benz and Gottlieb Daimler manufactured the first automobiles in Germany in the 1890s. They were knows as wheeled motor vehicles without horses, with a top speed of 20 km/h. Journeys became easier and briefer and frequent stops to take care of the animals became unnecessary. Many disliked these vehicles since they were difficult to start, they would emit black smoke, make noise and often break down.
In the meantime Carl Benz, from Germany, manufactured and released a 3-wheeled automobile with an internal combustion engine, which met little success. Due to its tubular steel wheels, it only reached a top speed of 12 km/h and produced severe vibrations.
While Armand Peugeot, from France, was building tools and bicycles in 1889, he created a steam car and in 2 years he began manufacturing gasoline cars. His greatest success was the Peugeot “Bebe”, released in 1912 and sold approximately 300 cars within the next 4 years.
In 1908, Ford produced “Model-T” which was easier to steer and cheaper than other automobiles, since it was the first one to be manufactured on an assembly line. Namely, every worker would add a part to the automobile, passing in front in front of them on a conveyor belt. It only took 90 minutes for this particular automobile to be assembled.
Henry Royce, an English mechanic and Charles Rolls, who loved automobiles, created a company. In 1910, they released the first luxury car, the Rolls Royce “Silver Ghost”.
As time went by, cars changed a lot. Today, they can move smoothly on the road and with great speed. They include comfortable seats, a luggage compartment, and an airconditioning system to maintain a pleasant interior temperature, a global positioning system, a stereo system for entertainment, even a telephone and a television set in particular cars. For the passengers’ safety, these are seatbelts and airbags, which inflate in case of an accident.
Most cars still use gasoline or diesel as fuel, which unfortunately cause environmental pollution or contribute to climatic change and the “greenhouse effect”, since their emissions contain carbon-dioxide, carbon-monoxide, nitrogen and sulphur oxides, unburned hydrocarbons and solid particles.
In order for emissions to be less harmful, poisonous gasoline additives were removed and unleaded gasoline was created. In the 1990s, catalytic converters were first used i.e. a component which converts fuel into vapour, carbon monoxide and dioxide.
Nevertheless, cars still cause serious environmental problems, therefore efforts have and are till made 1) to develop “green technology” in order to decrease the disadvantages of conventional cars, 2) to use two energy sources, with “hybrid” cars available, running on both liquid fuel sources e.g. natural gas, hydrogen, electricity, bio-diesel and liquid gas.
1) Conventional car manufacturers, using diesel or gasoline, presented new systems of “green” technology e.g. an automatic start-stop function while at traffic lights, low friction tires, lighter material (e.g. windshields), energy recovery while braking, control system electrical assistance, improved aerodynamic design etc. These new technologies achieve a 12-25% energy saving compared to a conventional car lacking them.
2) Hybrid automobiles run on two energy sources. A gasoline engine is the primary source, which functions together with an electrical engine, the secondary source of energy. The electrical energy necessary to move an automobile e.g. in the city, or to boost the efficiency of the gasoline engine e.g. while accelerating or driving uphill, is produced while in motion with the help of an advanced system which recovers the kinetic energy of the automobile and stores it in batteries. Today, hybridizations is widely spread and e.g. can even limit the fuel consumption of a middle class family car to 4-5 liters/100 km. Hybrid automobiles with greater energy efficiency after getting power from a does not burden the atmosphere of the cities in which it is driven. Current disadvantages are the common electrical outlet are in their last experimental stages. The advantages of hybrid cars are summarized in the following: they are less expensive to maintain, the use of an electrical engine in the city saves fuel, and less fuel give off less greenhouse emissions. They recharge their batteries while braking, recovering lost energy. They can also recharge while being idle e.g. while stopping at a traffic light. They also require significantly cheaper road taxes energy efficiency after getting power from a does not burden the atmosphere of the cities in which it is driven. Current disadvantages are the common electrical outlet are in their last experimental stages. The advantages of hybrid cars are summarized in the following: they are less expensive to maintain, the use of an electrical engine in the city saves fuel, and less fuel give off less greenhouse emissions. They recharge their batteries while braking, recovering lost energy. They can also recharge while being idle e.g. while stopping at a traffic light. They also require significantly cheaper road taxes.
3) a. Automobiles running on natural or liquid gas: Natural gas and liquid gas are more economical because of their lower cost, compared to gasoline, they have a large number of octanes, which makes special additives unnecessary, there is no corrosion caused by these additives and therefore there is greater car longevity, there is also a perfect combustion without smoke due to the lack of sedimentation in the combustion chambers, there is perfect mixture with air, since there is a mixture of two gases and not a liquid-gas one, during which there are problems with mixing air and gasoline, their fumes contain 60% less CO and 50% unburned hydrocarbons, while nitrogen oxide emissions are increased due to higher pressure and temperatures during combustion.
b. Hydrogen cars are still in experimental stage. A vehicle with fuel cell carries a hydrogen tank instead of a gasoline one. In a fuel cell, hydrogen is combined with atmospheric oxygen in order to produce electricity, thus there are no CO2 emissions or any other type, while the vehicle is on the move. Water is the only emission and is produced as a byproduct of electricity. The fuel cell operates as a compact electrical plant and not as a battery. A solid and efficient lithium battery stores the electricity produced upon braking and decelerating. The battery collaborates with the cluster of fuel cells in order for the vehicle to operate.
The only existing problem is the lack of a hydrogen-recharging station network, which should be developed in order for this technology to be applicable.
c. In an electrical automobile, the engine and a cluster of batteries replace thousands of other components of hybrid and conventional vehicles. This automobile does not need to have its oils changed, does not have an exhaust pipe, a tank or complex fuel systems, moreover in order to achieve greater efficiency and better space distribution, the power-assist mechanism can be integrated in the wheels. Additionally, disadvantages are the cost of the batteries and their limited capacity, as well as the absence of any kind of noise, which can be considered dangerous.
A lot of research is being done on an automobile running on biofuel. This fuel, based on alcohols, like methanol, can be synthetically produced out of carbon dioxide found in the atmosphere, as well as hydrogen.
Hence the amount of carbon dioxide emitted by internal combustion engines running on methanol can be nullified, since it is used in order to produce it.
Bibliography
- Disney Children’s Encyclopedia, 2007
- Newspaper “Ta Nea”, 26-27 June 2010
- Typos Sunday, 23 October 2011
- Magazine Eco, 2010
- www.econews.gr, Last visit Dec.2011
Iconography
| Experimental School of University of Macedonia, Thessaloniki, Greece |
| Victoria Datsi |
