Stability of an Al-Fumarate MOF and Its Potential for CO₂ Capture from Wet Stream

In this work, a new aluminum fumarate MOF was investigated regarding its water stability and CO₂ adsorption in the presence and absence of water. The adsorption equilibrium isotherms were measured at 303, 323, and 348 K for CO₂ and at 288 and 313 K for water vapor. Water vapor adsorption isotherms are type IV and were fit using the Langmuir-Ising model. The adsorption capacity of CO₂ at 303 K and 1.0 bar was 2.1 mmol/g and remained constant after exposure to humidity and regeneration. The isosteric heats of adsorption were 21 and 44 kJ/mol for CO₂ and H₂O, respectively. Fixed bed experiments were performed at 303 K to determine breakthrough curves of CO₂, water vapor, and the CO₂/water vapor mixture. Binary breakthrough indicated a reduction of only 17% in CO₂ adsorption capacity for a stream with 14% RH. The remarkable stability of this MOF suits it for such applications as CO₂ capture and thermal storage with water