An efficient CO2 adsorptive storage using MOF-5 and MOF-177

Carbon dioxide produced from carbon capture technologies could efficiently be stored into adsorbent materials. Certain types of metal organic frameworks called MOF-5 and MOF-177 are distinguished adsorbents amongst other porous materials owing to their high CO₂ uptake at medium storage pressure (10–50 bars). CO₂ adsorptive storage and energy-consumption analysis at pressures between 5 and 50 bar were numerically investigated using MOF-5 and MOF-177. An experimentally validated model was developed using User Defined-Function (written in C) linked to ANSYS Fluent program. The CFD two and three dimensional models have been validated against experimental data for adsorption storage characteristics of hydrogen on activated carbon. The developed model is feasible to accurately simulate and represent gas adsorptive systems. The results of the multidimensional modeling showed that the 2D model is properly adequate to present the adsorptive storage processes. The results obtained from CO₂ adsorptive storage using MOF-5 and MOF-177 emphasized that MOF-5 is a good choice for CO₂ storage applications at pressure less than 5 bar, while MOF-177 is a superior storage medium for the same purposes at higher pressures (≥10 bar). The optimal storage pressure for both adsorbents may be taken as 30 bar with CO₂ uptake and energy consumption about 21.07 mmol g⁻¹ (0.93 kg_CO₂ kg_MOF⁻¹) and 231 kJ tonne_CO₂⁻¹ for MOF-5, and about 32.5 mmol g⁻¹ (1.43 kg_CO₂ kg_MOF⁻¹) and 233 kJ tonne_CO₂⁻¹ for MOF-177, respectively. Importantly, the CO₂ storage is the next step after its separation from a flue gas using any separation method, and the first step prior to underground geological sequestration. The CO₂ adsorptive storage using MOF-177 showed an efficient method to store much more CO₂ quantity with lower energy-consumption than those of traditional storage systems (gas cylinders – without MOFs).