An experimental evaluation of the performance of a SI internal combustion engine for agricultural purposes fuelled with different bioethanol blends

The tests evidenced that the mixture tends to get lean with alcoholic fuels; the brake specific fuel consumption increased due to the lower LHV of bioethanol, while the highest brake thermal efficiency was obtained with E50. Minor torque and power reductions were recorded with the ethanol blends. The concentration of UHC decreased with E50 and E80 while NOx emissions reduced because of the lower combustion temperature due to the bioethanol cooling effect and the leaner mixture. In contrast, the concentration of CO increased because a poor homogenization of the charge and a lower combustion temperature had facilitated the formation of partial oxidation products.