Experimental and numerical study of the emission of Nox by the addition of isooctane to unleaded commercial gasoline for a spark–ignition engine

Abstract

The objective of this article is to evaluate, through an experimental and numerical study, the effect of the addition of isooctane on the performance and Nox emissions of a spark–ignition engine four different mixtures in addition to gasoline were tested in a spark–ignition engine using the DIN70020 standard at full load. The tests were conducted by adding 10, 20, 30, and 40% isooctane by volume to unleaded commercial gasoline. This practice makes a significant contribution to improving engine performance, increasing fuel efficiency, and reducing pollutant emissions. As a result, the addition of isooctane is establishing itself as a standard in the manufacture of premium fuels, providing not only an improved driving experience but also preserving the health of the engine. Extensive studies have been conducted to explore the potential of isooctane as a fuel in this regard. NOx emissions were reduced by adding a proportion of isooctane to unleaded commercial gasoline for all fuel blends, which could be explained by the high vaporization enthalpy of isooctane. This reduces the maximum temperature reached in the cylinder and thus reduces nitrogen oxide (NOx) emissions. A significant reduction in emissions of approximately 5% is achieved for the I10 blend (10% isooctane + 90% unleaded commercial gasoline) with the maintenance of engine performance (torque and power). This experimental study is confirmed by a numerical simulation using the DIESL-RK software with an average convergence of results that varies from 0.47% to 5.01%.