Kinetic Models | Skarstrom Docs

Kinetic Rate Models

Kinetic models describe the rate of adsorption and desorption. Skarstrom implements several models for mass transfer.

Linear Driving Force (1st Order)

The first-order linear driving force (LDF) model assumes the driving force is proportional to the difference between equilibrium and current adsorbed concentrations:

\frac{\partial q_i}{\partial t} = k_i (q_i^* - q_i)

Linear Driving Force (2nd Order)

The second-order LDF model uses a quadratic driving force:

\frac{\partial q_i}{\partial t} = k_i (q_i^* - q_i)^2

Symbol	Description	Unit
$k_i$	Mass transfer coefficient	s⁻¹
$q_i^*$	Equilibrium adsorbed concentration	mol kg⁻¹
$q_i$	Current adsorbed concentration	mol kg⁻¹
$t$	Time	s