The determination of activity coefficients at infinite dilution with the help of the dilutor technique (inert gas stripping)

The activity coefficient at infinite dilution (limiting activity coefficien t) represents an important property, which is used in particular for the se lection of selective solvents (e.g. extraction and extractive distillation) and for the reliable design of thermal separation processes. The removal o f the last traces of impurities causes the largest separation effort. In or der to avoid an oversizing of the column (e. g. distillation column) which would lead to an increase of the investment and operating costs, reliable i nformation about the separation factor at infinite dilution is required.