Real Driving Emissions, comparison between Ethanol (E85) and Gasoline fuels

Abstract

It is not new that people have been searching for a more environmentally friendly alternative for fossil fuels. In early 2000’s, Sweden saw potential in Ethanol and created benefits for people who bought E85 vehicles. Unfortunately, not everything was good about E85 and when people discovered the downsides of this renewable fuel, they started to lose interest, leading to the downfall of E85. Nowadays, the Swedish government tries to revive Ethanol as it is an important step of their 2030 vision to have a vehicle fleet running on renewable fuels only, so they plan on giving money to people to retrofit their old vehicles for E85. This thesis will study the impact of E85 on the emissions, as there are some important differences between gasoline and E85, like well-to-wheel emissions and energy density. The study includes the influence of driving style, route, and cold/warm start for a more complete understanding of factors that contribute to higher emissions. The measurements were done using an AVL M.O.V.E. PEMS device which provides measurements of CO2, CO, NOx, and PN. Vehicle parameters data were logged from an i-bus device and then the post-processing was carried in MATLAB. The results show that some parameters, like NOx and PN are more sensitive to aggressiveness, and the effect is even higher for E85. CO and CO2 are also increasing for the aggressive driving, but even so, the vehicle complies to EURO IV standards for which it was certified. E85 emits more CO and PN especially during aggressive driving, even though in the case of CO emissions most of them are emitted before the catalyst reaches the operating temperature, making the impact of fuel less notable. There was no important difference between the two routes, so they were studied together.