Nitrogen-rich hyper-crosslinked polymers for low-pressure CO 2 capture

摘要

Graphical abstractDisplay OmittedHighlights?Nitrogen-rich hyper-crosslinked polymers were synthesised for selective CO2capture.?A high CO2/N2selectivity of 52 was achieved corresponding to a 91% stream purity.?CO2adsorption capacity reached 1.56?mmol/g at 273?K and 1?bar.?Adsorbents had low isosteric heat of adsorption of 28–35?kJ/mol.?Retrofitting the adsorbents to CO2capture system led to a low net energy penalty.AbstractA series of poly[methacrylamide-co-(ethylene glycol dimethacrylate)] (poly(MAAM-co-EGDMA)) porous polymeric particles with high CO2-philicity, referred to as HCP-MAAMs, were synthesised for CO2capture. The polymers with a MAAM-to-EGDMA molar ratio from 0.3 to 0.9 were inherently nitrogen-enriched and exhibited a high affinity towards selective CO2capture at low pressures. A techno-economic model based on a 580 MWelsupercritical coal-fired power plant scenario was developed to evaluate the performance of the synthesised adsorbents. The presence and density of NH2moieties within the polymer network were determined using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The thermogravimetric analysis (TGA) showed that the polymers were thermally stable up to 515–532?K. The maximum CO2adsorption capacity at 273?K was 1.56?mmol/g and the isosteric heat of adsorption was 28–35?kJ/mol. An increase in the density of amide groups within the polymer network resulted in a higher affinity towards CO2at low pressure. At a CO2:N2ratio of 15:85, CO2/N2selectivity at 273?K was 52 at 1?bar and reached 104 at ultra-low CO2partial pressure. The techno-economic analysis revealed that retrofitting a HCP-MAAM-based CO2capture system led to a net energy penalty of 7.7–8.0%HHVpoints, which was noticeably lower than that reported for MEA or chilled ammonia scrubbing capture systems. The specific heat requirement was superior to the majority of conventional solvents such as MDEA-PZ and K2