Experimental analysis of evaporative emissions of ethanol-blended gasoline in automotive tanks at different temperature conditions

Automobiles are major sources of Volatile Organic Compounds (VOCs) and Very Volatile Organic Compounds (VVOCs), which are emitted not only from their tailpipes while running but also as evaporative emissions from gasoline fueled vehicle tanks and supply systems; these emissions are the main source of pollution for both standard and hybrid vehicles. VOCs and VVOCs can have significant effects on human health and environment, so emissions are subject to many regulations, both European and international, that are becoming increasingly stringent every year. In this paper, an experimental activity has been carried out to evaluate the fuel vapor generation from gasoline-filled fuel tanks. These experimental tests have been conducted by means of a Variable Temperature mini-SHED in Stellantis N.V. laboratories, at the Pomigliano Technical Center, in Italy. Different conditions of temperature and filling levels have been analyzed by monitoring the fuel vapors coming from the tank to the carbon canister. Tests have been divided in two groups with both constant and variable temperatures, by following standard temperature cycles, defined by regulations. Results are presented in terms of vapor temperature profiles and canister mass variation; they demonstrate the high influence of the environment temperature and of the filling levels on the emission.