Molecular Simulation Study of the Competitive Adsorption of H<sub>2</sub>O and CO<sub>2</sub> in Zeolite 13X JoosLennart SwisherJoseph A. SmitBerend 2013 The presence of H<sub>2</sub>O in postcombustion gas streams is an important technical issue for deploying CO<sub>2</sub>-selective adsorbents. Because of its permanent dipole, H<sub>2</sub>O can interact strongly with materials where the selectivity for CO<sub>2</sub> is a consequence of its quadrupole interacting with charges in the material. We performed molecular simulations to model the adsorption of pure H<sub>2</sub>O and CO<sub>2</sub> as well as H<sub>2</sub>O/CO<sub>2</sub> mixtures in 13X, a popular zeolite for CO<sub>2</sub> capture processes that is commercially available. The simulations show that H<sub>2</sub>O reduces the capacity of these materials for adsorbing CO<sub>2</sub> by an order of magnitude and that at the partial pressures of H<sub>2</sub>O relevant for postcombustion capture, 13X will be essentially saturated with H<sub>2</sub>O .