SI Engine Performance and Emissions using Surrogate Fuel for Oxygenated Gasoline

Gasoline is a complex mixture, composed of hundreds of different hydrocarbons. Surrogate fuels decrease the complexity of gasoline and are being used to improve the understanding of internal combustion engines (ICEs) fundamental processes. Computational tools are largely used in ICE development and performance optimization using simple fuels, because it is still not possible to completely model a commercial gasoline. The kinetics and interactions among all the chemical constituents are not yet fully understood, and the computational cost is also prohibitive. There is a need to find suitable surrogate fuels, which can reproduce commercial fuels performance and emissions behavior, in order to develop improved models for fuel combustion in practical devices, such as homogeneous charge compression ignition (HCCI) and spark ignition (SI) engines. Representative surrogate fuels can also be used in fuel development processes. In this study, the performance, combustion and emissions of a gasoline surrogate fuel was investigated and compared to a high-octane oxygenated gasoline. SI engine dynamometer tests were conducted and several parameters were analyzed. This paper shows that mixtures of iso-octane, toluene, n-heptane and ethanol could be used as surrogate fuels for commercial oxygenated gasolines to adequately reproduce engine torque, combustion and efficiency results. Other components should also be considered in order to enhance emissions representativeness.