Influence of contribution of biofuels derived from renewable materials in the fuel on the combustion process and toxic compounds emission of compression ignition engine

The use of liquid fuels as an energy source for internal combustion engines is unavoidable nowadays, further consumption increases with the development of industry and economic growth of the country. The abundance of the world in fossil fuels is a highly controversial issue; however, irrespective of forecasts concerning deposits of mineral fuels, undisputable fact is that these are resources, which will deplete. Economic, environmental and legislative issues also impose a limitation of use of fossil fuels. Under the problems associated with fossil fuels, an interesting alternative may be fuel derived from renewable sources. Biodiesel understood as a renewable energy source, used to feed compression ignition engines seem to be the ideal solution to meet energy needs, facing so called economic circulation era. Many research results confirm that combustion of pure biofuels in the currently highly advanced injection systems causes many problems. Different biofuel properties from diesel, such as viscosity or density directly influences on combustion process and emission of toxic components in the exhaust gases. Therefore, biodiesel blends with diesel fuel in all proportions; the combustion of such mixtures carries a number of benefits, from consumption reduction of non-renewable resources to reduction of harmful components in the exhaust gases. In this paper, the effect of doping methyl esters on the process of combustion and exhaust gases emissions in a compression ignition engine feed with mixtures of esters and diesel was examined. Tests were performed on four-cylinder, CI Andoria ACDR engine equipped with Common Rail fuel injection system. In order to investigate the combustion process, cylinder pressure and toxic components in exhaust gases steady state measurements were performed.