Measurements of the Mutual Diffusion Coefficients of Gases by the Taylor Method : 1st Report, Development of the Measuring Apparatus

Abstract

An apparatus for the measurement of the mutual diffusion coefficients of gases has been developed using the Taylor dispersion method. The present apparatus uses a thermistor TCD as the concentration detector, and it can be applied to oxygen-rich sample gases. The mutual diffusion coefficients of the H₂O-N₂, H₂O-O₂, H₂O-air, H₂O-CO₂ and H₂O-Ar systems have been measured at 150°C and 1atm. The result agrees well with reliable existing data for the H₂O-N₂ system. The uncertainty of the present results was estimated to be ±3%. The mutual diffusion coefficients of the H₂O-N₂, H₂O-O₂ and H₂O-air systems are found to be close to each other at 150°C.