Amine-impregnated polymeric resin with high CO2 adsorption capacity for biogas upgrading

Abstract

Solid amine materials are promising adsorbents for CO2 capture from biogas, flue gas and other similar gas mixture. Here, tetraethylenepentamine (TEPA)-impregnated porous polymeric resin (ADS-17) with very high CO2 adsorption capacity was successfully prepared. Its CO2 separation performance from simulated biogas was investigated by breakthrough experiments. And the influence of parameters such as TEPA loading, adsorption temperature and flow rate on the adsorption behaviours were studied in detail. The optimal TEPA loading was 40 wt% (ADS-17–40%TEPA) and the CO2 adsorption capacity of this adsorbent reached the optimal value (ca. 264.2 mg▪g−1) at the flow rate of 200 mL▪min−1. The CO2 adsorption capacity of ADS-17–40%TEPA had no pronounced change from 25 °C to 70 °C, but it decreased obviously when the adsorbent was heated to 90 °C. At 100 °C, the adsorption capacity became negligible. According to detailed characterization, it was inferred that the pores of ADS-17–40%TEPA in the range of 13–115 nm were probably responsible for CO2 diffusion. In addition, ADS-17–40%TEPA possessed good reversibility and the CO2 adsorption capacity was nearly stable after two adsorption–desorption cycles. ADS-17–40%TEPA with high and fast CO2 adsorption exhibits a very promising application in CO2 separation from biogas.