Jerzy Merkisz

By Jerzy Merkisz, Paweł Fuć, Piotr Lijewski and Miłosław Kozak

The use of biofuels is justified by the common agricultural policy decisions, by the need to improve environment protection and by the search of alternative energy sources. In such a context, methyl esters of vegetable oils, known as biodiesel and ethyl alcohol are receiving increasing attention as alternative fuels for automotive engines. The main advantages of biodiesel and ethyl alcohol are that these fuels are nontoxic, biodegradable, and renewable with the potential to reduce engine exhaust emissions, especially with regard to greenhouse gases emission. The fact that these biofuels are available in larger and larger quantities is of great importance as well. Currently, in the European market the most important biofuel is FAME (Fatty Acid Methyl Esters) manufactured mainly as Rapeseed Methyl Esters (RME). It is forecasted that the scale of production and consumption of this fuel will continue increasing as a result of the growing demand for diesel fuels and a levelled demand for spark-ignition engine fuels. Currently, FAME is added to regular diesel fuels in the amount of up to 7%. Besides, its consumption in a pure form grows as well. This chapter presents ecological properties of RME in relation to conventional diesel fuel. The aim of the research was to determine the potential of RME in reducing exhaust emissions (CO, HC, NOx and PM) from diesel engines operated in buses. The tests were carried out in real operating conditions of a city bus meeting EEV emissions standard. Comparative analysis made it possible to assess the environmental performance of buses depending on the type of fuel used. The obtained results indicate a slightly lower emission of CO, HC and PM when the vehicle was fuelled with RME but at the same time its application results in a slight increase in the emission of NOx. It seems that similar level of exhaust emissions recorded regardless of fuel type results from an advanced exhaust gas aftertreatment system (SCR + DPF) which was applied in the test vehicle.

Part of the book: Alternative Fuels

By Jerzy Merkisz, Michał Dobrzyński, Miłosław Kozak, Piotr Lijewski and Paweł Fuć

This chapter concerns the problem of assessing the exhaust emission from the engines of city transport buses fuelled by CNG. It presents a comparative analysis of toxic exhaust emissions of CO, HC, NOx and PM, from urban buses powered by diesel and CNG. The measurements were carried out over the SORT standardised cycles as well as during a real drive condition on a city bus route. The research revealed that CNG bus generates significantly lower NOx emission, whereas its CO and HC emissions are higher. Taking into account low PM emissions, CNG buses should be regarded as eco-friendly means of public transport.

Part of the book: Alternative Fuels

By Jerzy Merkisz, Piotr Lijewski, Paweł Fuć, Łukasz Rymaniak and Andrzej Ziółkowski

This paper is a synthetic approach to real driving (RDE) from selected vehicles: light-duty vehicle (LDV), heavy-duty vehicle (HDV). The tests were performed with the portable emission measurement system (PEMS) equipment under actual traffic conditions. The paper discusses problems of measurement methodology and emission of CO, HC, NOx, and PM. The performed investigation confirms that the main problem is the emission of NOx and PM, which usually is higher than the emission level. The obtained results show that the RDE method is very complex, but is the only way to provide invaluable information on the actual on-road exhaust emissions, not obtainable under laboratory conditions. In recent years, methods of exhaust emission testing under actual operating conditions have been developing rapidly. New technologies for extra low engine emissions pose a new question: does emission testing in a standard laboratory reflects real life emissions of a vehicle in use? In order to answer this question, it is necessary to measure the vehicle in-use emissions. Today, we know that the engine operating conditions (engine load and speed) in laboratory tests are not compliant with the conditions of actual operation. That is why the results of such tests are so desirable.

Part of the book: Improvement Trends for Internal Combustion Engines