Like all alcohols, ethanol offers significant opportunities in order to decrease the main emissions levels, to the improvement of the energetic performances of the internal combustion engines and to diminish the consumption of the classic petroleum products. Higher ethanol combustion qualities allow engine operation at leaner dosages compared to the case of using only gasoline, this fact assuring an increase of the engine efficiency.
Research works performed at POLITEHNICA University from Bucharest have used ethanol-gasoline mixtures in different proportion (E20, E85) for supplying a spark ignition engine. The studies have emphasized the possibility of engine to work with leaner dosage than in that case when only gasoline is used, performing an increase of engine performances and decreasing the fume exhaust (carbon monoxide CO, hydrocarbons HC and nitrogen oxides NOx). Moreover, using ethanol - gasoline mixtures an increase of the engine power is obtained compared with gasoline only, at the same energetic consumption.
The paper presents a thermo-dynamic gas analysis of the processes developed inside the cylinder of the SI engine and some results of the experimental investigations.