3. Non-isothermal adsorption

Since adsorption is exothermic, if the concentration of component A in the external fluid phase is high, adsorption can no longer be considered isothermal.

In the concerning catalytic chemical reactions, we will show that temperature variations inside particles are generally negligible compared with temperature variations in the particle's outer boundary layer.

Under these conditions, the energy balance at the adsorbent particle level is limited to : $\left(-\text{Δ}H\right)\frac{\text{d}\ll C^{\ast }\gg }{\text{d}t}=C_{\text{v}}\frac{\text{d}T}{\text{d}t}+ha\left(T-T_0\right)$