Modeling of biodiesel cetane number for motor transport

Declining production of cars with diesel engines in Europe, which have both high nitrogen oxides, as and carbon dioxide emissions, leads to the fact that cars with these engines are increasingly sold in Ukraine. In the cities of Ukraine, «route» buses with diesel engines are still used and transport companies try to replace smaller buses with larger ones with the same diesel engine. In this situation, the use of biodiesel seems promising for Ukraine. Cetane fuel number is one of the most important characteristics that shows the ability of fuel to burn in the internal combustion engine. As a rule, biodiesel has higher cetane number than diesel fuel. The analysis of biodiesel cetane numbers made from used oil is performed in the work. The formula for calculating the cetane number of such fuels based on their molecular composition is proposed. A good agreement of cetane number modeling data with experimental data obtained by the results of spectral analysis of fuels was obtained. Cetane numbers are calculated for the components (methyl esters of fatty acids) that make up diesel biofuel. The exact value of the cetane number of biodiesel is very important for modelling the combustion characteristics of this fuel. Cetane numbers of diesel biofuels and their components are the basis for calculating the ignition delay of these fuels. To avoid poor spraying, biodiesel is mixed with diesel fuel. Renewable diesel fuel has a lower density but higher cetane number values than diesel fuel. Therefore, the study of combustion characteristics of mixtures of diesel biofuels with renewable fuels may be the subject of further research