Studies on the transport properties of fluids at high pressure : II. The diffusion of 14CO2 in the carbon dioxide-argon and carbon dioxide-methane systems at high pressures (The co-operative researches on the fundamental studies of the liquid phase reactions at high pressures)

Abstract

The diffusion coefficients of ^14CO_2 in the ^12CO_2-Ar and ^12CO_2-CH_4, system were measured over the pressure range from 15 to 250atm at 25, 50 and 75℃. The measurements were made through a plug of porous bronze in the diffusion cell using the radioactive tracer technique. In most cases the products of the diffusion coefficient and the density increase slightly with an increase in density in the region of lower density and decrease in the region of higher density. In some systems the products increase consistently with an increase in density under the present experimental conditions. The increase of the products with an increase in density in the binary diffusion is not predicted by Enskog-Thorne's theory, which requires that the products decrease with an increase in density. The values of the products extrapolated to 1 atm agree with the published experimental values and those predicted by Wilke's equation.