Aq. Clark et al., VAPOR-LIQUID-EQUILIBRIUM OF (ETHERS PLUS HYDROCARBONS OR METHANOL OR WATER) FOR MOTOR GASOLINE MODELING, Fluid phase equilibria, 133(1-2), 1997, pp. 239-246
Modern environmentally beneficial methods of formulating motor gasolin
e often use alcohols and/or ethers as octane improvers, Thus, the ther
mophysical properties of these substances have become important in pro
cess engineering design, the simulation of gasoline blending operation
s, and engine operability. In all of these applications, phase equilib
rium properties are represented by thermodynamic models, which are der
ived from a combination of theory and experimental data. This work see
ks to quantify these models from careful measurement of key thermodyna
mic properties. Vapour-liquid equilibrium measurements on 2-ethoxy-2-m
ethylpropane (ETBE), 2-methoxy-2-methylbutane (TAME) and 2-methoxy-2-m
ethylpropane (MTBE) with various alkanes, aromatics and oxygenates hav
e been made over a temperature range of 293 to 323 K using a static ex
perimental method. These data are utilised in the development of a fle
xible model for the thermodynamic properties of motor gasolines. The d
ata are well correlated by the UNIQUAC excess Gibbs model for the liqu
id phase and with the Hayden-O'Connell correlation for the virial equa
tion for the gas phase. Prediction of the vapour phase composition abo
ve a gasoline containing MTBE and methanol show maximum differences of
0.0353 in mass fraction. (C) 1997 Elsevier Science B.V.