What estimation of the dynamic viscosity $\eta = f(T)$ $([\eta] = \pu{Pa·s})$ of the gas mixture components would you recommend during adsorption at a low temperature, approx. $\pu{293 K}$ to $\pu{333 K},$ and a relatively low pressure?

Gas mixture contains $\ce{N2}$ (the major component), $\ce{CO2}$ and $\ce{H2O}$ in the form of water vapor.

I assume the gas mixture to be ideal.

About a year ago, I use to calculate the dynamic viscosity using Lennard–Jones coefficients for a slightly different conditions if I recall correctly. However, I cannot find my calculations, hence I wanted to check whether using these coefficients would be relevant for such case.

  • $\begingroup$ What is "gas separation" ? $\endgroup$
    – Karl
    Dec 26, 2020 at 22:00
  • $\begingroup$ @Karl I referred to adsorption - corrected. $\endgroup$
    – Josh E.
    Dec 27, 2020 at 11:23
  • $\begingroup$ Ah, OK. Still: I could make a lot of assumptions about the process you have in your mind, and then the question would make sense. But I'd rather you told us. $\endgroup$
    – Karl
    Dec 27, 2020 at 14:08
  • 4
    $\begingroup$ See Bird, Stewart, and Lightfoot, Transport Phenomena, Chapter 1 for mixing rules to get viscosity. $\endgroup$ Dec 27, 2020 at 14:23
  • $\begingroup$ @ChetMiller Thanks, I think I got it by combining either Sutherland Equation with Herning-Zipperer Eq. or probably more precise Chapman-Enskog theory with Herning-Zipperer Eq. If I can ask you one more question... I can apply the Chapman-Enskog theory to obtain values of gas components/mixture conductivity $\lambda_k$ and binary diffusion $D_{AB}$. What would you recommend to use for molecular diffusion $D_m$, between two gases, which I need to obtain axial dispersion coefficient $D_{ax}$, which lumps all the negative effects on separation, thanks. (I'd neglect $H_2O$ in the first attempt.) $\endgroup$
    – Josh E.
    Dec 28, 2020 at 8:53


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