24 Ekim 2007 Çarşamba

Enviromentally Friendliness of Vehicles

21st century. Such a weird and interesting century. Technology has been increasing very rapidly. We throw away our technological toys every year and buy new toys. We change our cars with stronger engines and lesser fuel consumption. World become smaller every year. New roads, vehicles, computers, ideas, etc. On the other hand, we have struggled with more problems: general problems such as hunger, poverty, AIDS, etc.; new diseases which can’t be cured, environmental hazards which cause climate changes, health problems. In order to prevent these problems, scientists think more and more and offer new ideas. One of these ideas is environmentally friendliness of vehicles, shortly green car (this term will be used more in this essay). In other words, vehicles that cause less pollution or damage the environment lesser. Of course, there are some types of becoming a green car: Hybrid cars, ethanol fuel, diesel/biodiesel fuel, natural gas and other technologies.

First of all, hybrid cars are the most reasonable solution for the present. Simply, hybrid car means a car which uses two or more sources of power, mostly a rechargeable battery (electrical energy) and gasoline. The history of hybrid cars goes to the early years of engineering. Unfortunately, its importance isn’t understood until increasing of air pollution and Arabic petrol crisis in 1973. After that, automotive engineers speeded up building hybrid models. The advantages of hybrids vary upon the brand. But it can be easily said that the car pollute much less than normal cars and much quieter. The computer of the car decides how much it uses electric or gasoline. But if the driver is careful, the car uses less gasoline. Generally, it depends on how hard you step on the gas pedal; the car’s computer will determine how much power to draw from combustion engine, and how much power to pull from the car’s electric motor. Besides these useful facts, hybrid cars are expensive (due to its new technology and rare usage), heavier because of battery packs; have exposure risk, few spare parts and a need to professional repairing.

Secondly, using ethanol fuel is very popular nowadays. Ethanol is ethyl alcohol, also called grain alcohol. Chemically, fuel ethanol is identical to the alcohol we drink. Ethanol comes from starchy crops, sugary crop and cellulosic plants. Ethanol is mostly used as 15% of whole fuel (E85). Also, ethanol is a renewable fuel that comes from agricultural feedstocks, and can be produced domestically. Using ethanol (particularly E85) also results in less pollution, reducing smog-forming emissions by as much as 50 percent relative to gasoline. E85-powered vehicles also contribute to global warming, although experts disagree about how much greenhouse gas is emitted by using ethanol. However, ethanol can be more expensive than gasoline and contains less energy than gasoline.

Thirdly, using diesel instead of gasoline is another popular trend, especially in Turkey. In a diesel, air is drawn into the cylinder and compressed first without fuel present. This compression heats the air to such a high temperature that when fuel is then injected into the cylinder, it combusts. By using higher compression ratios and higher combustion temperatures, diesels operate more efficiently. As a result, diesel vehicles attain better fuel economy than their gasoline counterparts. However, diesel produces two important pollutants: particulate matter, the black cloud that trails many older diesel vehicles and NOx, a key ingredient in the formation of urban smog and acid rain. Although there are a few more disadvantages including price, diesel cars are still reasonable because of its fuel economy, longevity of its engine and its greater torque than gasoline.

Fourthly, using natural gas instead of gasoline and also diesel has become popular gradually. Natural gas, which is 90 percent methane, has a much higher octane rating than gasoline, allowing for higher compression ratios and therefore greater efficiency in the engines that use it. Natural gas burns so cleanly that CNG vehicles rival hybrids in producing extremely low levels of smog-forming pollutants. Moreover, natural gas vehicles (NGV) rate higher in particulate matter 10 (PM10) emissions. Also, NGVs are safer because of strength and thickness of their fuel storage tanks. Furthermore, they are cheaper, convenient and abundant. On the other hand, NGVs need special cylinders which increase the price. Also, they have limited driving range. Limited fuel stations and slower filling time are other disadvantages. Furthermore, natural gas is also a fossil fuel so that it can’t be considered a renewable resource.

Finally, there are other solutions instead of gasoline. One of them is electric cars. One of the great hopes of the past decade was rapid charging, a simple concept that would find public and home chargers capable of renewing an electric vehicle’s batteries in 10 to 20 minutes rather than the usual six to eight hours. So rapid charging is the main problem of increasing popularity of electric cars. Solar energy is another idea. Although solar energy is free and available everywhere; total cost of converting industry, vehicles and unpractical usage are huge handicaps. Another solution is hydrogen for fuel. Although hydrogen is everywhere and can be produced in so many ways, there isn’t much pure hydrogen around because hydrogen tends to bond easily with other elements. To make hydrogen fuel, hydrogen must be separated from whatever it’s attached to, a process that requires energy. So hydrogen hasn’t been a suitable energy yet.

In conclusion, there are many variable ways to make a green car. But each depends on technological developments and political ideas. So none of them is such a successful energy that it can beat up popularity of gasoline. But, there is hope in the future that one of them will become the main energy of vehicles.

Hiç yorum yok: