Accurate computer simulation of phase equilibrium for complex fluid mixtures. Application to binaries involving isobutene, methanol, methyl tert-butyl ether, and n-butane
M. Lisal et al., Accurate computer simulation of phase equilibrium for complex fluid mixtures. Application to binaries involving isobutene, methanol, methyl tert-butyl ether, and n-butane, J PHYS CH B, 103(47), 1999, pp. 10496-10505
We have developed a new method, called the reaction Gibbs ensemble Monte Ca
rlo (RGEMC) method, for the computer simulation of the phase equilibria for
multicomponent mixtures, given an intermolecular potential model for the c
onstituent molecular species. The approach treats the phase equilibrium con
ditions as a special type of chemical reaction and incorporates knowledge o
f the pure-substance vapor pressure data into the simulations. Unlike macro
scopic thermodynamic-based approaches like the Wilson and the universal qua
sichemical functional group activity coefficients (UNIFAC) approximations,
no experimental information concerning the mixtures is required. In additio
n to the PTxy phase equilibrium data, the volumetric properties of the mixt
ure are calculated. We developed intermolecular potential models based on t
he optimized potentials for liquid simulations (OPLS) of Jorgrensen and use
d the RGEMC method to predict phase equilibrium data for the binary systems
isobutene + methyl tert-butyl ether (MTBE) and the binaries formed by meth
anol with isobutene, MTBE, and n-butane. The predictions are excellent, and
of comparable accuracy to those obtained using the Wilson and the UNIFAC t
hermodynamic-based approaches, even though such approaches use experimental
mixture information.