High-pressure vapor–liquid equilibria of the second generation biofuel blends (2-methylfuran + iso-octane) and (2-methyltetrahydrofuran + di-n-butyl ether): Experiments and PCP-SAFT modeling

Vapor–liquid equilibria are investigated for two promising biofuel blends: 2-methylfuran (2-MF) + iso-octane and 2-methyltetrahydrofuran (2-MTHF) + di-n-butyl ether (DNBE). Vapor–liquid equilibria of fuels are of major importance as critical factor for the air–fuel mixture formation in a combustion engine. We collected bubble-point pressures of these two binary biofuel blends. The experiments were conducted in the temperature range of 353–508 K at pressures of up to 3.7 MPa using a visual synthetic method (Cailletet method). A slight positive deviation from ideal behavior was found for the mixture of 2-MF + iso-octane. The extent of the deviation increases with decreasing temperature. A more pronounced negative deviation from ideal behavior was found for the mixture 2-MTHF + DNBE. The extent of the negative deviation increases with increasing temperature. For correlation of the experimental data, the PCP-SAFT equation of state was used in combination with one-fluid mixing rules, using a binary interaction parameter for the dispersion interaction. It was shown that PCP-SAFT correctly predicts the mixture behavior from pure component data only.