The Determination of Activity Coefficients at Infinite Dilution with the Help of the Dilutor Technique (Inert Gas Stripping)

Limiting activity coefficients were measured for different solutes (methanol, ethanol, 1-propanol, n-pentane, n-hexane, n-heptane, 1-hexene, cyclohexane and benzene) and solvents (n-hexadecane and N-methyl-2-pyrrolidone (NMP)). An important prerequisite for the method is the achievement of exactly one theoretical stage in the equilibrium cell. For this reason, first of all the influence of different parameters (gas flow rate, liquid vessel and stirrer speed in the cell) on the phase equilibrium was investigated.