Modification of activated carbon by MIL-53(Al) MOF to develop a composite framework adsorbent for CO2 capturing

Abstract

In this research, a novel composite is synthesized based on activated carbon and MIL-53(Al) through the solution mixing method at different MOF weight fractions, and the CO₂ loading of prepared samples are measured in the batch and continuous apparatus. The structure, crystallinity, surface area, and chemical functionality of activated carbon, MIL-53(Al), and developed composite are characterized through BET, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The CO₂ and N₂ adsorption capacity of activated carbon, MIL-53(Al), and composites are examined in an isothermal batch reactor at the pressure range 0-110 kPa and equilibrium temperature 305 K. The adsorption isotherm of CO₂ is correlated by the Langmuir and Toth models. Besides, the performance of composite is compared with MIL-53(Al) and activated carbon in a continuous packed bed at flow rate range 15-25 ml min^-1 and temperature 32 °C, and the breakthrough curves are developed. The results show that increasing MOF content in the composite increases CO₂ adsorption capacity, so the CO₂ loading of synthesized composite containing 10%, 20%, and 30% MOF is 1.608, 1.704, and 1.792 mmol gr^-1, respectively.

Keywords: Activated carbon; Breakthrough curve; CO2 capture; Composite adsorbent; MIL-53(Al) MOF.