Regenerable CO2 Sorbents Based on Potassium Carbonate and Carbon Nanotubes

Abstract Developing efficient methods for CO2 capture is of critical importance for solving the problem of decarbonization and maintaining the composition of the air environment in closed life support systems. Regenerable sorbents based on potassium carbonate (K2CO3) provide reversible absorption of CO2. However, for their effective operation it is necessary to use porous supports that ensure dispersion of the active component and increase the rate of sorption. Carbon nanotubes (CNTs) are promising supports due to their high specific surface area and chemical and thermal stability. In this work, regenerable K2CO3/CNT sorbents were synthesized. Their sorption properties were studied under conditions simulating CO2 removal in life support and decarbonization systems. The maximum sorption capacity of 15 wt % CO2 was achieved on a sorbent containing 71 wt % K2CO3. The obtained regenerable materials are characterized by stable sorption capacity in sorption–regeneration cycles, which opens up prospects for their practical applications.