抄録
Ethers and alcohols used as gasoline additives have been much attention as octane number enhancing and environmental protection agents. Methyl tertiary butyl ether (MTBE) seems to be one of promising ethers. The vapor-liquid equilibria (VLE) of these mixtures such as MTBE+alcohol+alkane are needed to understand the phase behavior in producing and blending operations. Therefore, VLE of four binary systems containing MTBE (MTBE+methanol, MTBE+n-heptane, MTBE+n-octane, and MTBE+i-octane) and three ternary systems (MTBE+methanol+n-heptane, MTBE+methanol+n-octane, and MTBE+ methanol+i-octane) at atmospheric pressure are discussed. The correlation or prediction of VLE can be usually performed by using activity coefficients for liquid phase. It is found that VLE of these binary systems can be correlated by Wilson equation and VLE of the ternary systems can be predicted by using the parameters determined with binary VLE data. Further, a modified ASOG previously proposed was adopted to the present binary and ternary systems. The Flory-Huggins entropy term was revised based on the infinite dilution activity coefficient data of alkane binary mixtures. A contact probability factor between groups was introduced to distinguish the isomers. The ASOG group interaction parameters were determined by using VLE data of the present binary and ternary systems. The prediction performance was found to be good as Wilson equation.
