Changes in the Quality of E15-E25 Gasoline during Short-Term Storage up to Four Months

摘要

Nowadays, the main reason for the blending of biofuels stems from the necessity to reduce greenhouse gas emissions. Depending on market requirements, all gasoline fuels should be blended with 5-25 vol % ethanol. Low-blend ethanol gasolines are characterized by alcohol contents ranging from 5 to 10 vol % in Europe and up to 15 vol % in the United States. The achievement of new emission reduction targets and implementation of the requirement to replace fossil energy with renewable energy set out in RED Directive 2009/28/EC will demand blending of 20-25 vol % ethanol gasoline in Europe. Such blends should be stable while being kept in storage or car tanks for a certain time. This article presents the results of research on the evaluation of changes in the physicochemical properties and parameters characterizing the chemical stability of E15 E25 gasoline during short-term storage. Studies have shown that after 4 months of storage, ElS, E20, and E25 gasoline did not meet the required minimum in vapor pressure and E70 the distillation parameter and density in relation to the requirements of the EN 228 standard. In the studied gasolines, the water content increased rapidly during storage for up to 4 months. It was found that the determination of the induction period does not differentiate E15 from E25 in terms of stability. A clear differentiation was observed in the determination of unwashed gum content as well as existent gum and "potential gum. The results obtained in this research show that low-blend ethanol gasoline even during short-term storage (i.e., less than 4 months) requires special handling.