where the pellet radius R p = 2 mm and effective pellet diffusivity D * p = 5 × 10 -8 m 2 /s represent the macropore (or intercrystalline) diffusion ignoring external film resistance. The crystallite radius R µ and diffusivity D µ represent the micropore (or intracrystalline) diffusion. Thermal management is achieved using a temperature-controlled water stream flowing through the heat exchange jacket of the bed as well as direct heat exchange through steam or cooler flue gas. The competitive adsorption of CO 2 , N 2 and H 2 O is modelled as a multi-component mixed Langmuir isotherm derived from the combination of pure component isotherms.