Infinite dilution volatilities of polar chemicals in paraffinic hydrocarbons

The removal of trace organic solutes from chemical products is an important operation in chemical, petrochemical, food and pharmaceutical industries. Most widely used in purification processes, such as distillation, stripping and absorption, it utilizes the differences of the equilibrium vapor and liquid concentrations, requiring vapor-liquid equilibrium (or VLE) data or correlations for the system consisting of the trace solute and product. However, accurate VLE data and/or their correlations are not usually available for the mixture at the temperature and concentration ranges of industrial importance. Group contribution methods such as UNIFAC and ASOG provide the activity coefficients of mono-functional chemicals with fair accuracy over a relatively small temperature range. The equations of state with new mixing rules promise to be versatile for the correlation of VLE involving polar chemical mixtures, but no reliable prediction method has been reported yet. This paper presents a correlation method for infinite dilution volatilities of polar chemicals in a wide variety of paraffinic solvents between the temperature range of about 293.2 and 413.2 K, with about 8% accuracy.