Tert-amyl methyl ether (TAME). Thermodynamic analysis of reaction equilibria in the liquid phase

Article abstract of DOI:10.1021/je990191p

Ethers obtained from C₅ olefin streams provide a good mix of octane-enhancing and CO-reducing qualities. They are considered as a replacement for the more common isobutylene-derived fuel additives, e.g., MTBE. Data on the thermodynamic reaction equilibria for the synthesis of TAME, which is produced from the etherification reaction of 2-methyl-1-butylene and 2-methyl-2-butylene with methanol, were computed by studying TAME decomposition in a recirculating batch reactor at different temperatures with activity coefficients obtained using the UNIFAC method. A comparison of experimental data and theoretical predictions showed the possibility of erroneous values reported in the literature for the standard Gibbs free energy of TAME formation. Expressions for the thermodynamic equilibrium constants as a function of temperature were developed. A corrected value for the Gibbs free energy of formation for TAME was also provided.