Evaluation of the potential of a 3D-printed hybrid zeolite 13X/activated carbon material for CO2/N2 separation using electric swing adsorption

Abstract

Zeolite13X is known for its higher CO2 adsorption capacity. The use of monolithic shaped materials allows a process with a lower pressure drop than traditionally packed beds, increasing the energy efficiency of the process. Additive manufacturing is an alternative for developing hierarchically structured adsorbent materials with improved geometries. In this study, the potential of a hybrid monolith with electrically conductive properties was assessed for CO2capture by applying an Electrical Swing Adsorption process. Themonolith was obtained by direct ink writing. In addition to the zeolite13X (47.5 %wt.), activated carbon (47.5 %wt.) was used to provide electrical conductivity to the material. Carboxymethylcellulose was used as a binder/plasticizer to assist in writing and provide mechanical stability. The properties of the monolith were analyzed by several techniques and were compared with its raw adsorbent materials. CO2and N2adsorption equilibrium properties and the adsorption dynamics were also evaluated to test the performance of the monolith in capturing CO2. During these tests, electrification to regenerate the structured adsorbent was used.Considering a stream with a molar fraction of 0.15 ofCO2and 0.85 of N2at 1 bar,the monolith presents a CO2/N2selectivity of 30.7. The application of electric current increased the monolith temperature due to the Joule heating effect and demonstrated the efficiency in achieving a faster regeneration of the adsorbent. The cyclic stability of the monolith was also evaluated in this work. This study proves the potential of using direct ink writing to produce structured adsorbent materials for CO2capture using an electric swing adsorption process.