New gas chromatographic instrumentation for studying mass transfer phenomena

The new method of reversed-flow gas chromatography for studying heterogeneous catalysis, diffusion, adsorption, evaporation, and other related phenomena, is now applied to study the mass transfer phenomena across the gas-gas, gas-liquid, and gas-solid interphases. As the model gas solute, the vinyl chloride monomer (VCM), which is of paramount importance in food and environmental sciences, was selected, while the second phase consisted of gaseous nitrogen, liquid water, and solid polyvinyl chloride (PVC). Using appropriate mathematical analysis, the following parameters were determined: (i) Diffusion coefficients of VCM into nitrogen, (ii) Diffusion coefficients of VCM into water, (iii) Partition coefficients of VCM between water and nitrogen, (iv) Constants of Henry's law for the adsorption of VCM by water, (v) Partition coefficients of VCM between PVC and nitrogen, and (vi) Enthalpies and entropies for the adsorption of VCM on the solid PVC. Comparison of the experimental results with those determined theoretically using various empirical equations, permits the calculation of the accuracy of the method used, and gives invaluable information about the rate-determining step for the transfer of VCM into water and PVC describing the experimental data.