ArticleThe short time use of biofuels in compression ignition engines is being studied by
many authors. However, in many cases the real long–term operation of the engine on biofuels
may cause problems. The article deals with the operation parameters of the combustion engine,
fuelled by n-butanol – rapeseed oil – diesel fuel blend, during 70 hours operation in total. Two
brand new diesel power generators Kipor KDE 6500 with output power of 4.6 kW were used for
certain testing. The first generator was operated on 100% diesel fuel and it was used as a reference
and the second generator was operated on experimental fuel containing 10% n-butanol – 20%
rapeseed oil – 70% diesel fuel blend. The generators were equipped with single cylinder
compression ignition engine Kipor KM 186 with the rated power of 5.7 kW. For the first 10
operating hours approx. 40% load was applied. Then, the generators worked for another 60
operating hours with approx. 70% load. The harmful emissions, smoke, fuel consumption and the
amount of produced particles were also measured after 10 hours run-in period and then after
another 60 hours of operation. Consequently, the results were compared. Measurements were
carried out at gradually increasing electric power output, approx. 14%, 28%, 42%, 56%, 68%,
82% and 95% (in results can be found in Watts). Emission analyser and opacimeter BrainBee and
Engine Exhaust Particle Sizer TSI were used for the measurements. The results showed increased
production of emission of the engine running on fuel blend after 70 hours of operation. On the
other hand, engine which operated on standard diesel reached lower fuel consumption. After 70
hours the blended fuel tended to produce more particles in comparison with diesel fuel
