Under the Adsorbate subtab you can define all parameters regarding the solute that adsorbs to the adsorbent solid.

The Carrier Fluid Type can be a Gas or Liquid depending on what the solvent is transported by. When you select Liquid the Concentration Definition for the solute is automatically set the Concentration and an Inflow Concentration in mol/m3 must be defined.

For Gases the Concentration of the solute can be Defined in three different ways:

• Concentration: Directly prescribe an Inflow Concentration in mol/m3 that is transported into the domain via the fluid flow.
  
• Partial Pressure: Define the Partial Pressure of the gas that adsorbs to the adsorbent. The Partial Pressure is the pressure of that gas as if it alone occupied the entire volume of the original gas mixture at the same temperature. The Absolute Pressure is the sum of the partial pressures of the gases in the mixture. You can select from a wide range of units to define the pressure.
  
• Molar Fraction: Define the Molar Fraction which is the ration between the amount of the solute substance and the total amount of all substances in a mixture. The fraction can be expressed in parts per million (ppm), parts per billion (ppb), per mil (‰), or percent (%). Additionally, the Absolute Pressure needs to be defined.
  

An Initial Concentration c0 in mol/m3 can be defined in one of two ways. An Initial Field can be loaded by selecting the checkbox and clicking Browse. Through this option, an initial distribution of the solute in solution in the structure can be defined. For each time batch, AddiDict automatically generates a ConcentrationLoadingXXX.hht file. This file contains two volume fields: the Concentration and the Loading. Here the Concentration, i.e., the distribution of the solute in the structure is used as input. Therefore, the output of a previous adsorption simulation can easily serve as the input for subsequent runs. Alternatively, *.hht files can be manipulated with Python scripting.

Alternatively a Constant Value for the Initial Concentration of the solute in the structure can be defined.

If none of these options is selected the Initial Concentration is c0 = 0 mol/m3.