Experimental Investigation of Usage Limits of Various Alcohol-Based Fuels in Spark Ignition Engine

Current ambitious targets of transport utilized fossil fuels replacement pose a considerable challenge while transportation affordability, energetic and precious materials security are to be maintained. Most of current solutions oriented to passenger cars fossil fuel replacement by more renewable resources are dependent on one method only. On other hand, each of them exhibits some drawbacks and benefits while a reasonable combination could mitigate number of limitations and include many of advantages. Such solution could be usage of wide range liquid fuels from renewable resources in a suitable spark ignition engine accompanied by common battery electricity storage. The aim of this experimental work was to develop and demonstrate possibilities and results of an uncomplex engine adaptation to a wide range of fuels obtainable from renewable resources suitable as a range extender to commonly proposed electric cars. The approach chosen used standard gasoline as a starting fuel followed by switching to neat alcohol based fuel. This goal embraced significant modifications to engine fuel system, utilization of different control system and proper fuel switching procedure and control of air to fuel ratio. The results show that a wide range of alcohol based fuels can be successfully used in properly modified engine operated as a range extender while carbon dioxide emissions from fossil fuel were typically lower than 100 g per engine cold-start. Further, no fuel specific spark advance modification was needed and control system was able to keep air to fuel ratio in sufficiently narrow range resulting in reasonably low emissions of both regulated and unregulated pollutants according contemporary emission standards. Furthermore, no fuel-specific engine modifications, only some control system adjustments, were necessary to obtain reported results.