aP-x,y Equilibrium data of the binary systems of 1-Butanol and 2-Butanol with argon at 313.15 K and 333.15 K - Measurements and modeling

The equilibrium composition of two binary systems (argon-1-butanol and argon-2-butanol) was measured at 313.15 K and 333.15 K and at pressures up to 640 bar. A high-pressure optical view cell was used for the experiments, while theoretical calculations were based on the Peng-Robinson Equation of State with the BostonMathias alpha function. Different equilibrium compositions of argon in butanol isomers, as well as butanol isomer in argon were observed despite the similar molecular weight of isomers (M1-butanol = 74.121 g mol-1 and M2-butanol = 74.122 g mol-1) and a functional hydroxyl group. The difference in vapour pressure, dipole moment and solute-solute interactions lead to different solubility values. Nevertheless, the importance of data predicted by theoretical calculations is based on the possibility of obtaining an approximation to the thermodynamic behaviour of the real systems without the necessity of experimental data.