(113b) Using Adsorption Microcalorimetry and Manometry to Measure Useful Data for Adsorbent Screening and Process Design

Adsorption microcalorimetry has been proposed in the literature as a useful technique to characterize adsorbent surface and heterogeneities. By coupling a manometric setup to a Tian Calvet calorimeter, for instance, it is possible to simultaneously measure equilibrium adsorption isotherms and differential calorimetric curves. Additionally, it is also possible to assess intraparticle mass transfer kinetics by fitting experimental calorimetric peaks to a convenient mathematical model based on mass and heat balances applied to the sample cell and surge tank. We show different models with increasing degree of complexity and the coefficients of diffusion which may be extracted by fitting experimental data. Therefore, a useful set of parameters may be measured by this single technique: adsorption isotherms, heats of adsorption as a function of loading and intraparticle diffusivity. This is information usually required for adsorbent screening and the design of fixed bed adsorbers. Examples will be shown for different classes of porous solids aiming at CO₂ adsorption. An extension of the technique, originally applied to single gas adsorption, will also be shown for binary gas mixtures.