CO2 flow in Nanoporous media in Packed Column.
 

Hello,
I have just started working and trying to simulate CO2 gas adsorption in porous media i.e nanoporous activated carbon for fixed bed packed column and studying hydrodynamics at the moment using Ansys CFX14. I have made the geometry and done meshing. In CFX-Pre while setting up the gas flow in porous media using Porous Domain at basic settings, we get the options of "Fluid and Particle definitions" and "Solid Definitions"..Now I want to ask that where should we define activated carbon as adsorbent? Either in "Fluid and Particle definitions" alongwith CO2 or in "Solid Definitions" or no need to define it and just give the values of permeability, volume porosity and loss coefficient in "porosity settings". I put only CO2 in"fluid and particle definitions" but whenever I try to define activated carbon in"solid definitions" as user it doesn't work and material comes aluminum. From this it looks like"solid definitions" in the case means material of the wall....Is it so? My point is what does"solid definitions" specifically mean? i.e material of the wall or only adsorbent or simply no need to input anything in it and give the values in porosity settings. I hope you well understood my predicament. I am very confused about this..Please help me.
Also I have got the value of inlet velocity of the gas which I presume is superficial velocity.In porosity settings should I define the loss velocity type as superficial or true velocity type? The other important thing is whether in the option of value of volume porosity, I need to define the bed porosity or porosity calculated from bulk density and particle density of the material? Please reply.. THANKS.