Under the Interaction subtab you can define all parameters regarding the adsorption reaction.
Rate
At the top the rate of the adsorption reaction needs to be defined. Currently, only the Linear Driving Force rate type is available. Find a description and the equation of this rate type here. The Linear Driving Force rate requires a Rate Constant kldf that is applied in the Rate Equation. Define this parameter below in kg/(m3 s). This parameter controls the speed of the sorption reaction.
Isotherm φ(c)
Select one of five Isotherm Models todescribes how the solute distributes between the liquid or gas phase and the surface of the adsorbent at constant temperature. These models mathematically relate the amount of adsorbed solute to the equilibrium concentration of the solute in the surrounding phase. To the right of the parameter fields, the isotherm is shown in a plot. The plot is automatically updated when selecting a different model or changing one of the parameters.
Choose the Freundlich isotherm model when you want to model adsorption on heterogeneous surfaces with sites of varying adsorption energies and without monolayer coverage or a finite number of adsorption sites. The Freundlich isotherm model requires the definition of two parameters: the equilibrium constant K (m3/mol) and the empirical exponent m.
Choose the Langmuir isotherm model when you want to model monolayer adsorption on a surface with a finite number of identical sites, where each site can hold only one solute molecule. The Langmuir isotherm model requires the definition of two parameters: the equilibrium constant K (m3/mol) and the maximum loading sm (mol/kg). The default values are for the adsorption of CO2 on a zeolite surface (see Coker and Knox, 2014).
If you have laboratory measurements with pairs of solute Concentration and adsorbent Loading you can select the Table option to directly use your data to prescribe the isotherm curve. The data can be copied from other sources such as *.txt or excel files and pasted to the table.
Use the Tóth isotherm model for systems that deviate from the ideal monolayer adsorption behavior described by the Langmuir isotherm model. This can happen especially at low and intermediate pressures. The Tóth isotherm model requires the definition of three parameters: the equilibrium constant K (m3/mol), the Tóth heterogeneity parametert, and the maximum loading sm (mol/kg).
For the Tóth Legacy model the Tóth parameters , , , , and need to be provided. The default values are based on the adsorption of CO2 on a zeolite surface (see CO2/13X in table 1 of Coker and Knox, 2014).
