Abstract
The environmental pollution and the decrease of the oil based fuels are the greatest problems of the automotive-industry at the start of the 21st century. There were and certainly there are a number of experiments to aiming substitute the petrol and the diesel oil with other fuels. One group of these substitutable fuels is the bioethanol - biodiesel - diesel oil mixtures. These mixtures are very similar to the fuels used today, as it can be used in the engines without any structural changes.
At the Technical University of Budapest investigations have been made to explore the possibility of using bioethanol - biodiesel - diesel oil mixtures in vehicles and agricultural engines. The main aspects of the researches was find blends that are substitutable for diesel oil consisting of the most renewable part as possible, reaching the same or similar power output and lower the emissions.
The experimentations were based on mixing bioethanol and biodiesel with diesel oil. Our idea was, when the biofuels are mixed they supplement each other, cutting the negative effect of each and increasing the renewable component rate in the fuel. During the researches the two main requirements of the fuel were: the maximal possible renewable part with which the engine does not need any changes, yet meets the prerequisites set by diesel oil and to have the same power and better emissions with the blend. The low (up to 20%) biofuel rate was important, while the first step of introduction is possible with low rates.
The experiments were maid at engine benches with different engines, one-cylinder measurements, cetin-number determination, viscosity determination, life cycle analysis and cost benefit analysis.
In conclusion of the research it could be established that the use of bioethanol-biodiesel-diesel oil emulsion in agricultural engines is in technicality already solved, as no changes are needed on the engine, and it also reduces the emissions and is economically justified.
Keywords:renewable fuels, sustainable development, engine bench measurements