Carbon Cryogel Preparation via Urea-furfural Gel Synthesis as an Adsorbent for CO2 Capture Application

Abstract

Adsorption of CO₂ using porous solid materials is one of the suitable separation techniques due to its low cost and simple operation. Porous carbon from urea-furfural has been prepared as a potential adsorbent for CO₂ capture. In this work, urea-furfural carbon cryogel (CCUF) was prepared using a simple polymerisation reaction under ambient conditions with different water and acid loadings followed by a drying and calcination process. The effect of water and acid loadings on carbon synthesis were evaluated for carbon gel yield and CO₂ adsorption performance in a fixed-bed adsorption study. The selected CCUF was characterised with N₂ sorption isotherms, CO₂ temperature-programmed desorption (CO₂-TPD), Fourier transform infrared spectroscopy (FTIR), and focused ion beam-scanning electron microscopy coupled with energy dispersive X-ray (FIBSEM-EDX) to understand the carbon surface structure and properties. The CCUF synthesised with 4 mL of water and 0.15 mL of acid loading was selected due to its high CO₂ adsorption capacity (2.04 mmol/g) compared to other carbon gels synthesised in this work. The large specific surface area (160 m²/g) of CCUF with high microporosity and nitrogen content provide capabilities for CO₂ adsorption under ambient conditions. The result shows that the N-enriched CCUF adsorbent has a potential for CO₂ adsorption.