Abstract
World fossil fuel reserves are finite and unevenly distributed around the globe, being an important source of emissions of greenhouse gases. In the context of limiting CO2 emissions and oil dependency European Union issued the Directive 2003/30/EC which requires that all Member States to replace 20% of energy with alternative sources. An original method that is using a dual fluidized bed gasifier to turn lignocellulose biomass into a syngas for combined heat and power production (CHP) is used for several years in Güssing, Austria. In a sidestream of this CHP the syngas is turned into a high cetane, sulphur free liquid biofuel by using the Fischer-Tropsch (FT) synthesis. This paper presents a comparison of the main emission of a compression ignition engine fueled with biofuels made from biomass by FT synthesis. The burned mass fraction center point was varied between 0º and 25º ATDC in the tests to observe changes in emissions by comparing the results using conventional diesel with mixtures consisting of 20% and 50% FT fuel. The engine operation point was kept constant at 2000 rpm and 15 bar bmep. It was studied the evolution of CO, NOx, HC, FSN and particle number. In this load point, the results showed a minor decrease in the FSN, the rest of the emissions of alternative fuels being almost at the same level with the conventional diesel fuel. The tests were conducted in the laboratories of the Institute for Powertrains and Automotive Technology, University of Technology, Vienna.
Keywords: Biofuels, Fischer-Tropsch Synthesis, Engine Emissions