DFT and canonical ensemble investigations of gasoline additives at the gas phase: ETBE, MTBE, DIPE, ethanol and methanol

A quantum analysis was performed with Density Functional Theory and a canonical ensemble, in order to predict thermodynamic properties of gasoline with additives at the gas phase. These calculated quantities included standard gasoline mixed with the following oxygenate additives: methyl tert-butyl ether, ethyl tert-butyl ether, diisopropyl ether, ethanol and methanol. For each gasoline and additive mixture, thermodynamic potential variations were calculated between room and the approximate ignition temperatures at 1 atm, where an analysis of the additive effect was performed in order to estimate relevant fuel properties at similar conditions to the injection step and combustion. Some thermodynamic quantities for combustion were obtained, showing substantial concordance with experimental data, relative errors being lower than 2%, thus establishing an excellent method for calculating and predicting the thermodynamic properties of combustion reactions for gasoline with additives.