Zeolites and molecular frameworks for adsorption-based syngas purification

As essential components of synthesis gas (syngas) purification routines, adsorption processes need substantial improvements to efficiently produce high-grade hydrogen (H2) and other industrial products. To this end, due to their uniform pore geometries, which bring precision, molecular sieving materials deserve more attention. This chapter examines the established, emerging, and potential uses of zeolites and other molecular sieves as adsorbents for syngas cleaning and further purification in the downstream processes. We first summarize syngas impurities and current purification routines to delineate the need for molecular sieves rather than other adsorbents with broader pore size distributions. We continue by explaining the basics of adsorption technology and the general properties of the molecular sieves. Then, we introduce the recent developments on molecular sieving-based purification for various syngas impurities. Lastly, we discuss several research directions that might facilitate the large-scale adoption of molecular sieves for the physical-adsorption-based purification of syngas.