Experimental and Simulation Study of Adsorption in Postcombustion Conditions Using a Microporous Biochar. 2. H2O, CO2, and N2 Adsorption

The adsorption behavior of humid mixtures that are representative of postcombustion conditions on a micro porous biochar was evaluated. The adsorption isotherms of H2O(v) were measured at 30, 50, and 70 degrees C up to the saturation pressure and fitted to the extended Cooperative Multimolecular Sorption (CMMS) model. Dynamic experiments were carried out in a fixed-bed adsorption unit with mixtures of N-2, CO2, and H2O(v)., Experimental results indicate that H2O is little affected by CO2 adsorption. On the other hand, the CO2 adsorption capacity can be reduced by the adsorption of H2O. The extent of this reduction is dependent on the amount of H2O adsorbed, which, in turn, is strongly dependent on the relative humidity of the gas phase and the adsorption time. A dynamic fixed-bed adsorption model that makes use of Ideal Adsorbed Solution (IAS) theory has been shown to be adequate to describe the adsorption behavior of CO, from the ternary mixtures in the full range of conditions evaluated.