Petrol Engine Exhausts

Chemometric evaluation methods can be applied to the signal from a single sensor by feeding the whole data set into an evaluation program [133,135]. Both principle component analysis (PCA) and partial least square (PLS) models were used to evaluate the data. These are chemometric methods that may be used for extracting information from a multivariate data set (e.g., from sensor arrays) [135]. The PCA analysis shows that the MISiC-FET sensor differentiates very well between different lambda values in both lean gas mixtures (excess air) and rich gas mixtures (excess fuel). The MISiC-FET sensor is seen to behave as a linear lambda sensor [133]. It 

One way to solve this problem, and thereby control emissions directly from the start, is to use a sensor based on a material more resistant to thermal shock as a cold-start sensor [128]. SiC, as the second hardest material in existence only surpassed by diamond, is such a material and has therefore been tested for its suitability as a cold-start sensor. The water-splash resistance of SiC is still not verified because these experiments are complicated to perform in a laboratory engine test bench. 

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Morgan A, Holmes A. 1978. The fate of lead in petrol-engine exhaust particulates inhaled by the rat. Environ Res 15 44-56. 

Little, P. Wiffen, R.D. (1977) Emission and deposition of petrol engine exhaust Pb. I. Deposition of exhaust Pb to plant and soil surfaces. Atmospheric Environment, 11, 437-47. 

Little, P. and Wiffen, R. D. (1977), Emission and Deposition of Petrol Engine Exhaust Pb — I. Deposition of Exhaust Pb to Plant and Soil Surfaces, Atmos. Environ., 11, 437-47. 

Engines. Vehicular petrol engines are potential ignition sources by means of the spark-ignition system, dynamo or battery, or hot exhaust pipe. Non-flameproof diesel engines are potential ignition sources due to a hot exhaust pipe or carbonaceous particles or flames from the exhaust. 

Petrol or LPG engine exhaust gas Diesel engine exhaust gas... 

In petrol engines the internal EGR concept is often implemented. This involves adjusting the exhaust valve timing so that some of the combusted gas is trapped in the cylinder [16]. This residual gas acts as a diluent for the next combustion cycle, hence lowering the combustion temperature. Internal EGR can only reduce NOx slightly, because no more than 5-10% of the exhaust gas can be trapped without significantly affecting combustion. 

In recent years the sulfur dioxide content of the air has risen, and so also have the nitrogen dioxide levels. This is due to increased use of fossil fuels and the fact that oxides of nitrogen are produced when some fuels and other materials burn in petrol engines. Catalytic converters on car exhausts help to reduce the amount of the oxides of nitrogen and carbon monoxide in the air, and so help to lower car emission pollution . 

Under certain conditions, dichloromethane (often the major constituent of chemical paint removers) can be converted into phosgene [238,747]. Tobacco smoke, exhaust gases from oil-fired furnaces or petrol engines, and hot metal surfaces are all reported to have a catalytic effect on the reaction [238] ... 

These irritate the upper respiratory tracts and eyes. The aldehyde content in the exhaust of petrol engined vehicles give rise to concentrations in the atmosphere that are already at the limit established for irritant effects (0.1 ppm). 

The stoichiometric amount of the air necessary for the complete combustion of 1 kg of petrol amounts to 14.6-15 kg (depending on the fuel composition). The fuel is, however, never perfectly mixed with the air and the ratio is not always stoichiometric. A mixture is typically used, which is richer by 50% as compared to the ideal mixture. These circumstances, together with the short time of the combustion itself, result in an incomplete burning of hydrocarbons, so that aldehydes and other organic compounds are produced, which can further react with burning products. Thus, in exhaust gases of a petrol engine, there is always a certain amount of non-combusted fuel, and products of incomplete combustion. 

Figure 1.9 Catalytic exhaust conversion for petrol engines (a) ceramic catalytic converter (b) schematic of a catalytic converter in action.

The area shall be cordoned off with no entry to vehicles having diesel/petrol engines (as these can emit sparks from exhaust pipes). 

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