Vehicle emissions control is the study and practice of reducing the motor vehicle emissions — emissions produced by motor vehicles, especially internal combustion engines.
Emissions of many air pollutants have been shown to have variety of negative effects on public health and the natural environment. Emissions that are principal pollutants of concern include:
Hydrocarbons – A class of burned or partially burned fuel, hydrocarbons are toxins. Hydrocarbons are a major contributor to smog, which can be a major problem in urban areas. Prolonged exposure to hydrocarbons contributes to asthma, liver disease, lung disease, and cancer. Regulations governing hydrocarbons vary according to type of engine and jurisdiction; in some cases, “non-methane hydrocarbons” are regulated, while in other cases, “total hydrocarbons” are regulated. Technology for one application (to meet a non-methane hydrocarbon standard) may not be suitable for use in an application that has to meet a total hydrocarbon standard. Methane is not directly toxic, but is more difficult to break down in a catalytic converter, so in effect a “non-methane hydrocarbon” regulation can be considered easier to meet. Since methane is a greenhouse gas, interest is rising in how to eliminate emissions of it.
Carbon monoxide (CO) – A product of incomplete combustion, carbon monoxide reduces the blood’s ability to carry oxygen; overexposure (carbon monoxide poisoning) may be fatal. Carbon Monoxide poisoning is a major killer.
Nitrogen oxides (NOx) – Generated when nitrogen in the air reacts with oxygen at the high temperature and pressure inside the engine. NOx is a precursor to smog and acid rain. NOx is a mixture of NO, N2O, and NO2. NO2 is extremely reactive. It destroys resistance to respiratory infection. NOx production is increased when an engine runs at its most efficient (i.e. hottest) part of the cycle.
Particulate matter – Soot or smoke made up of particles in the micrometre size range: Particulate matter causes negative health effects, including but not limited to respiratory disease and cancer.
Sulfur oxide (SOx) – A general term for oxides of sulfur, which are emitted from motor vehicles burning fuel containing sulfur. Reducing the level of fuel sulfur reduces the level of Sulfur oxide emitted from the tailpipe. Refineries generally fight requirements to do this because of the increased costs to them, ignoring the increased costs to society as a whole.
Volatile organic compounds (VOCs) – Organic compounds which typically have a boiling point less than or equal to 250 °C; for example chlorofluorocarbons (CFCs) and formaldehyde. Volatile organic compounds are a subsection of Hydrocarbons that are mentioned separately because of their dangers to public health.
In the United Kingdom, matters concerning environmental policy are what is known as “devolved powers” which means, each of the constituent countries deals with it separately through their own government bodies set up to deal with environmental issues in their respective country:
Environment Agency – England and Wales
Scottish Environment Protection Agency (SEPA) – Scotland
Department of the Environment – Northern Ireland
However, many UK-wide policies are handled by the Department of the Environment Food and Rural Affairs (DEFRA) and they are still subject to EU regulations.
Engine efficiency has been steadily improved with improved engine design, more precise ignition timing and electronic ignition, more precise fuel metering, and computerized engine management.
Advances in engine and vehicle technology continually reduce the toxicity of exhaust leaving the engine, but these alone have generally been proved insufficient to meet emissions goals. Therefore, technologies to detoxify the exhaust are an essential part of emissions control.
We take emissions very seriously at R.J. Davies and will look after your vehicle so emissions are kept to as low as possible. Book your vehicle for a service now and let us take care of it.