Since the invention of automobiles most vehicles have been powered by gasoline (petrol), diesel or propane. This is however changing with the increase of technology and with focus on the environment where we now require green cars. This means there is an outlook for cars with virtually less or no green house gas emissions.
The most commonly used power on the automobile industry is gasoline (which is in liquid form). So the use of Natural gas is a substitute to gasoline although it is possible to manufacture vehicles in such a way that they use both the gasoline and natural gas (bi-fuel vehicles). Natural gas is a fossil fuel that is lighter than air but disperses quickly upon release. This gas can either be compressed at high pressure (compressed natural gas) or can be liquidized at slightly higher pressure than the atmospheric pressure but very low temperature levels (liquefied natural gas).
This gas has previously been used to generate electricity, heat houses and as one of the constituent gases in several industrial processes. Although highly available in the reserves of the US only 1% of it is used. With an aim of having natural gas powered vehicles the earth would be brought to some greater balance. Most companies that had embraced this technology have pulled out due to a low demand but the Honda automobiles have vowed to keep on to this noble task. This paper therefore explores the possibilities of having a car entirely powered by the natural gas, the draw backs and the advantages.
The major challenge faced on the earth is comprehending its biosphere and the complex operations it undertakes. This has given scientists and environmentalists in the carbon cycle study a hard time as the try to figure out how the carbon dioxide quagmire can be solved. Burning of fossil fuels and other industrial processes (fuel exhausts included) have led to increased levels of carbon dioxide in the atmosphere hence, changes in the climate, increased temperature levels, a rise in the sea levels and extreme weather conditions.(Gray, Ralph D.1979) This therefore calls for urgent preventive measures in the control of carbon dioxide emissions.
Natural gas powered vehicles seems to be one of the most effective way of these control measures. It is not a very new concept in the US as they have been there since 1990s (Cannon, James S. 1995).the leading company in their manufacture is the Honda automobile company commonly known for the Honda Civic GX car that uses natural gas. These vehicles are common in Argentina, Brazil, China, India, Pakistan, Italy, Iran, North and South America. Although in US they were mainly used by the corporate or government fleet, it has the biggest market share in the world of 48 %( Begley, Sharon, & Mary Hager. 1994). The consumers can therefore buy from selected dealers. There has been some exposure to the public although at very limited levels. This trend is however changing due to increased levels of gasoline. The gas cannot be used in heavy duty trucks and its effect is on cars, light duty passenger vehicles, pickups, medium duty tracks, buses and trains.
Composition and energy content of the natural gas
Natural gas consists of hydrogen and carbon combined in their simplest form to form methane. The ethane combination may be present but in very minute quantity. Oxygen and nitrogen are also present with very little amounts to cause any effect. The hydrogen Sulfide gas if present should be filtered out as it is poisonous and is considered a contaminant. Natural gas has the highest production of energy on all gases produced through burning of fossils. The carbon in the gas is converted to energy almost all of it thus the little carbon dioxide emission. The combustion of one cubic meter of this gas gives 10.6 kWh of energy (Gray, Ralph D. 1979).
The natural gas powered car population in US
According to the Natural Gas Vehicle Coalition, there are 130,000 CNG vehicles in use in the United States, although this modest total includes heavy-duty vehicles (such as trucks and buses) as well as automobiles. Other countries, including Argentina and Brazil, boast more than 1 million CNG vehicles apiece (Hill, Stephen. 1996). The Honda company sells only 1000 natural gas cars out of the 300 000 it manufactures. The estimated number of natural gas powered vehicles stands at 5 million in the whole world. This is still way behind the target level that would aid in elimination of green gas emissions.
Advantages of natural gas powered cars
They take a shorter time of about three to five minutes to fill the cars tank compared to the time taken to fill in gasoline of the same amount to the tank (some couple of hours). Natural gas emits less carbon monoxide (70% less), nitrogen oxide (87% less) and carbon dioxide (20% less) as compared with gasoline (Lacey, Robert. 1986). This makes the gas more environmental friendly. On a smoggy day the gas emitted is much cleaner than the one it takes in. The gas is not volatile therefore has no major problems in safety handling. The compressed natural gas disperses quickly and is less flammable hence making gasoline that is in liquid form a much easier mode to catch fire. It is much cheaper and as it does not need to be imported. The aspects of car maintenance under natural gas are cut down because it has limited emissions and therefore the engine will last for a longer period. This gas is quite convenient as it can be brought to ones home through some home based fuel appliance connected to the owner's natural gas supply line. Natural gas may not be renewable like ethanol (also used as a power supply for automobiles), but there is so much of this natural gas in the reserve. Finally the use of natural gas in automobile is gaining more market hence increase in most fueling stations.
Draw backs in natural gas power in cars.
The new method of power supply to the automobile industry is faced with some serious challenges that lead to its limited supply. The first disadvantage of the method is inadequate stations selling natural gas. This makes it hard for the people who travel across the country. The natural gas power has very little driving range unlike gasoline. Another drawback is the perception of people and resistance to change. People think that natural gas is explosive and hold back from buying this kind of vehicles. This has a very negative influence as the auto makers who bring in these cars and the demand is little or none at all. The natural gas has a major problem with over the sea transportation as their pipelines can not be installed across the oceans. The natural gas in the compressed form is stored in steel or composite containers at a very high pressure. In its liquid form it needs some tanks that are vacuum insulated. (Nadis, Steve, & James J. 1993) The cylinders and tanks for the natural gas require much more space than the gasoline tank. This leaves the owner with no much space to carry other things in the car. In use of the natural gas powered vehicles the volume of gas required is high compared with that of gasoline therefore may raise the cost. Unlike the gasoline vehicles, the natural gas cars do not come with the high tech battery parks and dual gas-electric power. This makes the manufacturers to shun from making them because, the high tech battery pack vehicles use less production cost yet their sell is very high.
We do not need to wait for a time of crisis when there is a big health problem due to carbon dioxide emission so as to implement the right measures and switch to natural gas powered cars. Prevention is always better than cure. Measures should also be taken to improve the quality of these vehicles. Such measures as creating the gas tank or cylinder beneath the car's body would be very useful in space creation. The public should be sensitized on the use of these cars. Construction of light weight trailers with an extra tank and space for luggage for refuel capacity and more space for luggage would also be a wise idea.
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