Facilely synthesized porous polymer as support of poly(ethyleneimine) for effective CO2 capture

Abstract

In this work, an effective adsorbent (polyHIPE/PEI) was developed for use in CO2 capture technologies. For this purpose, a porous polymer was prepared by high internal phase emulsion (HIPE) using 2-Ethylhexyl methacrylate (EHMA) and divinylbenzene (DVB). This prepared porous polymer (polyHIPE) was then used as a novel support for the wet impregnation of polyethylenimine (PEI), thus resulting in the polyHIPE/PEI adsorbent. The prepared adsorbent was characterized using Fourier transform infrared spectroscopy (FTIR), solid-state nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET) surface area analyses. At the optimal PEI loading of 60 wt% on polyHIPE, the CO2 sorption capacity reached 4 mmol CO2/g-sorbent using 10 vol% CO2 and 3 vol% H2O in N2 at 70 °C. Kinetic and thermodynamic adsorption studies showed that the activation energies for CO2 adsorption and desorption of polyHIPE/PEI are 13.74 kJ/mol and 36.12 kJ/mol, respectively. These results indicate that CO2 desorption using polyHIPE/PEI has the potential to reduce CO2 capture cost due to the low activation energy and high CO2 desorption rate. As such, polyHIPE/PEI constitutes an advantageous alternative to traditional methods in CO2 capture from gas mixtures.