Chemical Engineering Research & Design, Vol.122, 77-96, 2017
Certainties and challenges in modeling unwashed and washed gums formation in Brazilian gasoline-ethanol blends
During the gasoline storage, gums are formed by a slow oxidation of some unstable compounds, such as olefins. The high molecular mass oxidation products can become insoluble and form deposits. Its excess affects the injection pattern, the fuel combustion, the durability of the fuel line parts and increases the pollutant emissions. Consequently, a robust knowledge is required to assess better the behavior of the fuel, in particular the impact of biofuels. This article discussed the certainties and challenges in modeling gum formation in blends of Brazilian gasoline with anhydrous ethanol. The impact of experimental and mathematical procedures on the robustness of the model was investigated. They make possible to assess quantitatively the impact of aging period, temperature, ethanol and additive contents in the formation of unwashed and washed gums. The results confirmed the promotion of the process with the increase of the temperature and aging period and showed the complex role of ethanol, strongly dependent on the values of the other factors. Moreover, the comparison with former literature showed that the models from this study were more robust and the dependence with chemical matrix of gasoline and ethanol quality was reduced. Recommendations were given to overcome the remaining challenges. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.