Sign Up   |   Welcome Guest  |  Login  

Car Articles

Read articles on cars and car industry. Get fully updated on all information related to cars. Read exciting happening in the Indian and Global Car industry, tips to help you and more...


Rate This Page

   Significant Advancements in Automotive Emission Control System


Automotive engineering has become so advanced that now the cars have become computerized with improved performance and lowered emissions. With the computerization of cars, many new technologies have been introduced which has dramatically reduced air pollution that is largely contributed by cars and other vehicles plying on roads.

Hydrocarbons, carbon monoxide, and oxides of nitrogen are emitted to the environment during the combustion process. The four main sources of these poisonous gases are engine exhaust, crankcase, fuel tanks, and carburetor. The exhaust pipe and the crankcase discharges burnt and unburnt gases like hydrocarbons, carbon monoxide, oxides of nitrogen, and sulphur that are harmful to both the environment as well as human health. In the fuel tank and carburetor the toxic hydrocarbons are continually evaporated from gasoline during the combustion process.

At the time when automobiles were introduced there was nil pollution contributed by them but as the numbers started increasing the rate of automotive pollution also started soaring. Today there are huge numbers of automobiles plying on roads that are enough to create a complete imbalance in the global environment. Fortunately, manufacturers have realized the consequences of the increasing automobile pollution and have introduced advanced pollution control devices that prove to be a perfect answer to emission control.

However, many car manufacturers like Hyundai, Honda, and Maruti Suzuki have come up with innovative engines that are both fuel-efficient and nature-friendly. Some of the key examples of the same are kappa engine by Hyundai, k-series engine by Maruti Suzuki, and i-VTEC engine by Honda.

Some of the significant advancements made in the automotive emission control system are as follows:

Catalytic Convertor

Catalytic convertor is a small device fitted in the exhaust system that helps to convert harmful gases released from the combustion engine into water vapour and carbon dioxide through a heat-producing chemical reaction. The device comprises a honeycomb made of platinum or palladium. Platinum or palladium serves the purpose of a catalyst that speeds up the chemical reaction. During the combustion process when harmful gases are passed over this catalyst the gases get chemically oxidized and gets converted to a non-poisonous form of gas comprising carbon dioxide and water vapour. While the convertor is doing its job, it generates heat and cleans the exhaust. The convertor requires more hard work if the exhaust is dirty and in the process more heat is generated that can prove to be fatal. So, it is very essential that the exhaust should be well cleaned. This feature installed in the emission control system is a good way to reduce harmful automotive emissions.

Positive Crankcase Ventilation Valve

Positive Crankcase Ventilation (PCV) system is a vital device of the automotive emission control system. The key purpose of the device is to take the vapours released during combustion and re-direct the vapours into the fuel intake so that they can be well burnt during combustion. These vapors actually dilute the air/fuel mixture so the release and re-directing of the vapours should be carefully controlled and metered in a way that it does not affect the engine performance. When the engine is at idle condition just a little of the vapours are allowed to be re-directed to the intake system. Whereas at higher speed, the air\fuel mixture is less critical and as the pressure is high more of the vapours are allowed to be re-directed into the intake system. The PCV valve has to be free from dirt and congestion because if the valve is clogged vapours will move back to the air filter that will create excessive pressure and may result in leakage of engine oil.

Exhaust Gas Recirculation Valve

Exhaust Gas Recirculation (EGR) valve is a vacuum controlled valve whose primary function is to re-circulate the exhaust and prevent the formation of any harmful gases composed of nitrogen. The work of the EGR is to gauge a small amount of exhaust gas into the intake system. In the intake system the exhaust gas then dilutes the air/fuel mixture that further lowers the combustion chamber temperature. This in turn prevents the formation of any nitrogen containing compounds as excessive combustion chamber temperature results in the release of oxides of nitrogen. Nitrogen being one of the major pollutants is then removed from the exhaust and this controls the level of pollution.

Air Injection

Air injection is a significant measure taken by car manufacturers to control car emissions. When fresh air is injected into the hot exhaust system, the fuel that is left unburnt gets burnt before it actually exits the tailpipe. As no engine is 100% efficient, there will always be some unburnt fuel in the exhaust and this actually increases the emissions of harmful hydrocarbons. So, the air injection system provides all the basic requirements for complete combustion comprising fuel, oxygen, and heat. This results in complete combustion and thereby reduces the emissions of hydrocarbons. In certain specific conditions when the fuel content is excessive, the injection of fresh air can prove to be damaging. That’s where the air injection system should be shut down using a diverter valve that actually does not shut down the system but diverts the air away from the exhaust manifold.
» Read more Articles On Car Manufacturers