(552a) Intensification of CO2 Capture and Separation with Hybrid Adsorbents for Combined Vacuum-Temperature Swing Adsorption

Recent literature shows that combined Vacuum-Temperature Swing Adsorption allow for a significant reduction in energy consumption in CO₂ capture [1,2]. An important parameter in such a cyclic process is the cycle time: in classical temperature swing processes: slow heating and cooling of the adsorbent result in large cycle times, large adsorbent inventories and reduced productivity.

In our work, we have developed a novel generation of hybrid porous materials, consisting of a CO₂-selective adsorbent, a binder and a ferromagnetic compound that allows direct, in situ heating of the adsorbent via induction heating. As compared to traditional heating methods, in which the adsorbent is heated indirectly, e.g. using a hot stripping gas, induction heating allows to directly heat the adsorbent from the core of the particle in a contactless way, resulting in very high heating rates and a reduction of heat losses. The method we developed is applicable to any kind of adsorbent or porous solid.

In this paper, we discuss the synthesis and performances of novel hybrid materials (including zeolites and MOFs). CO₂separation performance was evaluated using different strategies of simultaneous and sequential heating and evacuation. The adsorbate loading, bed pressure, bed temperature, and mole fraction of CO2 at the outlet were chosen as performance indicators.

Using these hybrid adsorbents, it is shown that total cycles times (adsorption, heating, desorption and cooling) of less than 5 minutes can be achieved. Examples of this approach in other applications will be given.

References: [1] Wurzbacher JA, Gebald C, Steinfeld A: Separation of CO2 from air by temperature-vacuum swing adsorption using diamine-functionalized silica gel. Energy Environ Sci 2011, 4:3584-3592. [2] Stampi-Bombelli V, van der Spek M, Mazzotti M: Analysis of direct capture of CO2 from ambient air via steam-assisted temperature–vacuum swing adsorption. Adsorption 2020, 26:1183-1197.