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.