Anhydrous bioethanol gasoline blends at high altitude above sea level in a SI engine: performance and specific emissions

Fuel in Colombia for spark ignition internal combustion engines (SI-ICEs) is composed of a mixture of 90% gasoline and 10% bioethanol (by percentage volume) called E10. Some of the largest cities in Colombia are located above 2200 m above sea level (masl). However, information regarding the emissions and performance of SI-ICEs fueled with E10 or other gasoline-bioethanol blends at such altitudes is almost non-existent in the literature. Testing was performed with an SI engine fueled with gasoline and anhydrous bioethanol ratios of E10, E15, E20, E40, E60, E85 and E100. These tests were conducted in the city of Bogotá, which is located at 2600 masl, with the engine operating at 3600 rpm and at various engine loads. The results show that the most efficient blend for these conditions is E40, resulting in a decreased brake specific fuel consumption of 2.5% compared to results obtained with the E10 blend. This change also leads to reductions in the specific emissions of hydrocarbons (HC), carbon monoxide (CO) and carbon dioxide (CO 2 ) of 52.88, 73.66 and 9.72%, respectively, while increasing the specific emissions of nitrogen oxides (NO x ) by 106.25%.