Abstract

Experimental vapor-liquid equilibria have been measured for the binary system methyl-tert-butyl ether + 2,5-dimethylfuran at 50, 75 and 94 kPa, and over the temperature range 308-364 K, using a vapor-liquid equilibrium still with circulation of both phases. In addition, a maximum differential bubble pressure tensiometry technique was used to measure atmospheric interfacial tensions at 298.15 K. From the experimental results reported here, it follows that the mixture exhibits slight positive deviation from ideal behavior over the whole concentration range, while the observed interfacial tensions exhibit slight negative deviation from the linear behavior. The determined vapor-liquid equilibrium data satisfy the Fredenlund's consistency test and were well correlated using traditional activity coefficient models such as Wohl, NRTL, Wilson and UNIQUAC. Interfacial tensions, in turn, were satisfactorily correlated using the Redlich-Kister equation. The phase and interfacial behaviors of the mixture were theoretically characterized by applying the square gradient theory to a Peng-Robinson Stryjek-Vera equation of state (EoS), appropriately extended to mixtures by means of the modified Huron-Vidal mixing rule. The so-developed model allows directly transferring the experimental excess Gibbs energy function to the EoS model for equilibrium calculation purposes. Results obtained according to this theoretical framework show that both experimental vapor-liquid equilibrium data and interfacial tensions can be accurately predicted. (C) 2013 Elsevier Ltd. All rights reserved.