The Effect of Using Ethanol-Gasoline Blends on the Mechanical, Energy and Environmental Performance of In-Use Vehicles

Abstract

Abstract:The use of ethanol in gasoline has become a worldwide tendency as an alternative to reduce net CO 2 emissions to the atmosphere, increasing gasoline octane rating and reducing dependence on petroleum products. However, recently environmental authorities in large urban centers have expressed their concerns on the true effect of using ethanol blends of up to 20% v/v in in-use vehicles without any modification in the setup of the engine control unit (ECU), and on the variations of these effects along the years of operation of these vehicles. Their main concern is the potential increase in the emissions of volatile organic compounds with high ozone formation potential. To address these concerns, we developed analytical and experimental work testing engines under steady-conditions. We also tested carbureted and fuel-injected vehicles every 10,000 km during their first 100,000 km of operation. We measured the effect of using ethanol-gasoline blends on the power and torque generated, the fuel consumption and CO 2 , CO, NOx and unburned hydrocarbon emissions, including volatile organic compounds (VOCs) such as acetaldehyde, formaldehyde, benzene and 1,3-butadiene which are considered important ozone precursors. The obtained results showed statistically no significant differences in these variables when vehicles operate with a blend of 20% v/v ethanol and 80% v/v gasoline (E20) instead of gasoline. Those results remained unchanged during the first 100,000 km of operation of the vehicles. We also observed that when the vehicles operated with E20 at high engine loads, they showed a tendency to operate with greater values of λ (ratio of the actual air-fuel ratio to the stoichiometric air-fuel ratio) when compared to their operation with gasoline. According to the Eco-Indicator-99, these results represent a minor reduction (<1.3%) on the impact to human health, and on the deterioration of the ecosystem. However, it implies a 12.9% deterioration of the natural resources. Thermal equilibrium analysis, at the tailpipe conditions (~100 • C), showed that ethane, formaldehyde, ethylene and ethanol are the most relevant VOCs in terms of the amount of mass emitted. The use of ethanol in the gasoline reduced 20-40% of those emissions. These reductions implied an average reduction of 17% in the ozone formation potential.

Alternative Fuels for Internal Combustion Engines

“…The octane number of ethanol is higher than the octane number of the gasoline. The high octane number of ethanol allows the use of ethanol as fuel in an SI engine with a higher compression ratio [40]. The latent vaporization heat of ethanol increase cooling effect in the cylinder, this situation leads to an increase in volumetric efficiency [41].…”

“…Recently environmental authorities in large urban centers have expressed their concerns on the true effect of using ethanol blends of up to 20% in-use vehicles without any modification in the setup of the engine control unit (ECU), and on the variations of these effects along the years of operation of these vehicles [40].…”

Characteristic of Gasoline Fuels in Indonesia Blend with Varying Percentages of Bioethanol

“…The effect of blended bioethanol with gasoline will more significance for characteristic [7]. The use of bioethanol becomes an alternative for booster octane number fuel to need a modern engine with high compression ratio engines, can increase efficiency of the engine with to increase compression ratio [5]. The objective of RON is the measure of blended bioethanol forward resistance to auto-ignition in the engine with comparing the mixture iso-octane and nheptane, controlled value compression ratio.…”

Evaluation of Evaporative Emission and Feasibility of an Onboard Refueling Vapor Recovery System for Scooters

“…The reduction of evaporative emission of fuel vapor has become one of the major issues. The fuel vapors released from traditional vehicles are mostly volatile organic compounds (VOCs) [2]. The equipment for improving environmental contamination caused by the evaporative emission of fuel vapor include the stage vapor recovery facilities placed at gas stations and onboard refueling vapor recovery (ORVR) systems incorporated in vehicles [3].…”