To generate power on motor vehicle fuel petroleum, chemical reactions occur in the burning of hydrocarbon compounds. Hydrocarbons are commonly used are octane. Basically, the reaction is :
C8H18 + 2502 8CO2 + 9H2O
This is a perfect combustion that occurs even though there are still pollutants, namely carbon dioxide (CO2). But in practice, the combustion that occurs is not always perfect, ie the carbon that is not perfect bind with oxygen so that there is residual carbon monooksida (CO) is a dangerous pollutant. There are also other harmful pollutants such as NOx and HC. These pollutants resulting from fuel octane compound contains not only alone, but often added with addictive substances. Because if the fuel contains only compound octane, the engine may not run perfectly. This addictive ingredient that contains elements of nitrogen.Dilihat of engine mechanics, the causes of pollutants that may arise in combustion, are described as follows:
Hydrocarbon Compounds Emissions
Gasoline is a hydrocarbon compound, so every HC-acquired vehicle exhaust indicates unburned fuel and combustion along with the rest wasted. Although the ratio between air and fuel ratio (AFR = Air-to-Fuel-Ratio) was appropriate and supported by the engine combustion chamber design is currently already close to ideal, but still only a portion of gasoline as if it can "hide" from the fire during the combustion process and cause the emission of HC in the exhaust tip is high enough. For cars not equipped with Catalytic Converter (CC), HC emissions that can be tolerated is 500 ppm and for cars equipped with the CC, HC emissions that can be tolerated is 50 ppm.
C8H18 + 2502 8CO2 + 9H2O
This is a perfect combustion that occurs even though there are still pollutants, namely carbon dioxide (CO2). But in practice, the combustion that occurs is not always perfect, ie the carbon that is not perfect bind with oxygen so that there is residual carbon monooksida (CO) is a dangerous pollutant. There are also other harmful pollutants such as NOx and HC. These pollutants resulting from fuel octane compound contains not only alone, but often added with addictive substances. Because if the fuel contains only compound octane, the engine may not run perfectly. This addictive ingredient that contains elements of nitrogen.Dilihat of engine mechanics, the causes of pollutants that may arise in combustion, are described as follows:
Hydrocarbon Compounds Emissions
Gasoline is a hydrocarbon compound, so every HC-acquired vehicle exhaust indicates unburned fuel and combustion along with the rest wasted. Although the ratio between air and fuel ratio (AFR = Air-to-Fuel-Ratio) was appropriate and supported by the engine combustion chamber design is currently already close to ideal, but still only a portion of gasoline as if it can "hide" from the fire during the combustion process and cause the emission of HC in the exhaust tip is high enough. For cars not equipped with Catalytic Converter (CC), HC emissions that can be tolerated is 500 ppm and for cars equipped with the CC, HC emissions that can be tolerated is 50 ppm.
Emissions of Carbon Dioxide (CO2)
CO2 concentration shows directly the status of the combustion process in the combustion chamber. The higher the better. At AFR, namely the comparison of air with fuel in the ideal number, CO2 emissions ranged from 12% to 15%. If the AFR is too lean or too rich, then CO2 emissions will drop drastically. If CO2 is below 12%, then we should see other emissions that indicates whether the AFR is too rich or too thin.
CO2 concentration shows directly the status of the combustion process in the combustion chamber. The higher the better. At AFR, namely the comparison of air with fuel in the ideal number, CO2 emissions ranged from 12% to 15%. If the AFR is too lean or too rich, then CO2 emissions will drop drastically. If CO2 is below 12%, then we should see other emissions that indicates whether the AFR is too rich or too thin.
Emissions of Carbon Monoxide (CO)
Carbon monoxide gas is a gas that is relatively unstable and tend to react with other elements. Carbon monoxide, can be changed easily to CO2 with the help of a little oxygen and heat. When the machine works with the proper AFR, CO emissions in exhaust tip ranges from 0.5% to 1% for a machine equipped with injection systems or about 2.5% for machines that still use carburetors. With the help of air injection system, then the CO can be made as low as possible close to 0%.
If the AFR little richer than the ideal rate of CO emissions will increase drastically. So the high rate of CO indicate that the AFR is too rich and this could be caused partly due to problems in such a fuel injection system that is too high fuel pressure, engine temperature sensor that is not normal, a dirty air filter, PCV system is not normal, a dirty carburetor or until its settings are not right.
Emissions of NOx Compounds
The third addition to the above gas, NOx emissions are not overlooked in making the diagnosis of the machine. NOx compounds are chemical bonds between the elements nitrogen and oxygen. Under normal conditions the atmosphere, nitrogen is very stable inert gas that will not bind with other elements. But in conditions of high temperature and high pressure in the combustion chamber, nitrogen will break ties and binds with oxygen.
NOx compounds are very unstable and when released into the atmosphere, will bind with oxygen to form NO2. This is very dangerous because these compounds are highly toxic and when exposed to water to form nitric acid.
The high concentration of NOx compounds due to the high concentration of oxygen coupled with the high temperature combustion chamber. To keep the NOx concentration is not high it would require a precise control of the AFR and the combustion chamber temperature must be maintained so as not too high. Normally NOx at idle does not exceed 100 ppm. If the AFR is too lean, ignition timing is too high or other causes which lead to increased combustion chamber temperatures, will increase the concentration of NOx. Piles of crustal carbon in the combustion chamber will also increase engine compression and can cause hot spots that can raise levels of NOx.
Carbon monoxide gas is a gas that is relatively unstable and tend to react with other elements. Carbon monoxide, can be changed easily to CO2 with the help of a little oxygen and heat. When the machine works with the proper AFR, CO emissions in exhaust tip ranges from 0.5% to 1% for a machine equipped with injection systems or about 2.5% for machines that still use carburetors. With the help of air injection system, then the CO can be made as low as possible close to 0%.
If the AFR little richer than the ideal rate of CO emissions will increase drastically. So the high rate of CO indicate that the AFR is too rich and this could be caused partly due to problems in such a fuel injection system that is too high fuel pressure, engine temperature sensor that is not normal, a dirty air filter, PCV system is not normal, a dirty carburetor or until its settings are not right.
Emissions of NOx Compounds
The third addition to the above gas, NOx emissions are not overlooked in making the diagnosis of the machine. NOx compounds are chemical bonds between the elements nitrogen and oxygen. Under normal conditions the atmosphere, nitrogen is very stable inert gas that will not bind with other elements. But in conditions of high temperature and high pressure in the combustion chamber, nitrogen will break ties and binds with oxygen.
NOx compounds are very unstable and when released into the atmosphere, will bind with oxygen to form NO2. This is very dangerous because these compounds are highly toxic and when exposed to water to form nitric acid.
The high concentration of NOx compounds due to the high concentration of oxygen coupled with the high temperature combustion chamber. To keep the NOx concentration is not high it would require a precise control of the AFR and the combustion chamber temperature must be maintained so as not too high. Normally NOx at idle does not exceed 100 ppm. If the AFR is too lean, ignition timing is too high or other causes which lead to increased combustion chamber temperatures, will increase the concentration of NOx. Piles of crustal carbon in the combustion chamber will also increase engine compression and can cause hot spots that can raise levels of NOx.
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