Benchmarking selective capture of trace CO2 from C2H2 using an amine-functionalized adsorbent
Jin‐Sheng Zou, Zhipeng Wang, Yassin H. Andaloussi, Jiapeng Xue, Wanli Zhang, Bryan E. G. Lucier, Zeyang Zhang, Yanan Jia, Xue-Cui Wu, Jiahan Li, Yining Huang, Michael J. Zaworotko, Guangjin Chen, Shoushun Chen, Yun‐Lei Peng
Abstract
Purifying C2H2 by removing trace CO2 is critically needed yet challenged by their analogous physical properties. Herein, we report a commercial resin adsorbent HP20 (Diaion® HP-20 Resin) loaded with polyethyleneimine (PEI@HP20) which selectively captures trace CO2 and excludes C2H2. PEI@HP20 possesses a high CO2 adsorption capacity (4.35 mmol/g) at 100 kPa and 298 K and a record CO2/C2H2 uptake ratio compared with all reported CO2-selective adsorbents. The ideal adsorbed solution theory selectivity reaches 1.33×107. The pilot-scale pressure-temperature swing adsorption on 2 kg PEI@HP20 further validated that it can obtain >99.99% purity C2H2 from CO2/C2H2(1/99, v/v) mixtures with a high yield of 344.7 g per cycle. The combination of multinuclear solid-state Nuclear Magnetic Resonance, Fourier Transform infrared spectroscopy and density functional theory calculations reveal that the performance of PEI@HP20 relies on a dual chemisorption/physisorption mechanism. This work highlights a promising method to develop green, low cost, high efficiency, and readily scalable CO2-selective adsorbent. Purifying C2H2 by removing trace CO2 is needed but challenging due to their analogous physical properties. Herein, the authors report the pilot-scale production of a commercial resin adsorbent loaded with polyethyleneimine for the selective capture of CO2 traces and exclusion of C2H2.