CO2 Capture by PEI-Impregnated Alumina Sorbents

Abstract

Direct air capture (DAC) or direct CO2 extraction from ambient air is a promising approach to reduce greenhouse gas emissions caused by both distributed (location independent) and point sources (location specific). Solid sorbents have been considered as more effective for DAC compared to the liquid counterpart since they have a faster kinetic and avoid volatile and heat losses due to the absence of evaporation of liquids. In this study, the alumina - supported polyethyleneimine (PEI) material was chosen as solid sorbents and their CO2 capture performance for different PEI loadings (20, 35, 50 wt%), flow rate (15, 30, 45 L/h) and adsorption temperatures (30, 40, 50, 60 °C) was investigated. Sorbents were prepared by using wetness impregnation method and their physical and chemical properties were characterized by several techniques such as N2 adsorption - desorption (surface area, pore size and volume), Scanning Electron Microscopy - SEM (surface morphology, surface chemical composition). The CO2 capture performance of sorbents were analyzed under different CO2 concentrations and the cyclic (adsorption - desorption) behavior of the sorbents were tested. The results show that alumina-supported PEI adsorbents are promising materials for CO2 capture with high CO2 adsorption capacity and stability.

Keywords

• PEI
• Adsorption
• CO2 Capture
• DAC
• Greenhouse Gas
• Alumina

References

1. Chen, C., Kim, J., & Ahn, W. S. (2014). CO2 capture by amine-functionalized nanoporous materials: A review. Korean Journal of Chemical Engineering 2014 31:11, 31(11), 1919–1934.
2. Darunte, L. A., Oetomo, A. D., Walton, K. S., Sholl, D. S., & Jones, C. W. (2016). Direct air capture of CO2 using amine functionalized MIL-101(Cr). ACS Sustainable Chemistry and Engineering, 4(10), 5761–5768.
3. Gargiulo, N., Caputo, D., & Colella, C. (2007). Preparation and characterization of polyethylenimine-modified mesoporous silicas as CO2 sorbents. In Studies in surface science and catalysis (Vol. 170, pp. 1938-1943). Elsevier.
4. Goeppert, A., Czaun, M., May, R. B., Prakash, G. K. S., Olah, G. A., & Narayanan, S. R. (2011). Carbon dioxide capture from the air using a polyamine based regenerable solid adsorbent. Journal of the American Chemical Society, 133(50), 20164-20167