Non-equimolar counter-diffusion in ternary gas systems

Previous studies of multicomponent gas diffusion, using mathematical and physical models, have dealt with equimolar diffusion in closed systems. To simulate respiratory gas transport more faithfully, we have investigated ternary gas diffusion in open systems, which allow non-equimolar diffusion to occur. Theoretical results showed the effects of gas composition on the induced fluxes. A unique state in which the diffusion system satisfies both the equimolar and non-equimolar conditions was found for gas systems in which the net flux changes as the composition varies. To verify the non-equimolar film theory, we conducted experiments with a diffusion cell apparatus. Diffusional fluxes across a porous membrane were obtained for N2-O2-SF6, N2-O2-Ne, and N2-O2-He combinations. The experimental results agreed with the predicted values, validating the theoretical film approach.