Synthesis of Guanidinium-Based Poly(ionic liquids) with Nonporosity for Highly Efficient SO<sub>2</sub> Capture from Flue Gas
Fei-Feng Mao, Yan Zhou, Wenshuai Zhu, Xiaoyan Sang, Zhang-Min Li, Duan‐Jian Tao
Abstract
Because of considerable adsorption capacities of competitive gases N2 and CO2, many kinds of porous materials suffer from unsatisfied SO2/CO2 and SO2/N2 selectivities and thus hardly achieve deep removal of SO2 from flue gas. Herein, a novel type of guanidinium-based poly(ionic liquid) with the feature of nonporosity was designed and prepared through a facile copolymerization procedure. It is very attractive that nonporous guanidinium-based poly(ionic liquids) P([allyl-TMG]Br-DVB) by polymerization of (allyl-tetramethylguanidine)bromide with divinylbenzene had almost excluded the adsorption of N2 (0.01 mmol g–1) and CO2 (0.07 mmol g–1) but showed very high SO2 capacity (9.79 mmol g–1) at 25 °C and 1 bar. The high selectivities of SO2/CO2 (452) and SO2/N2 (2294) were accordingly obtained. Furthermore, column breakthrough experiments confirmed the excellent separation performance of P([allyl-TMG]Br-DVB) in deeply eliminating 2000 ppm SO2 in the mixture of SO2/N2/CO2. The employment of nonporous poly(ionic liquids) as efficient adsorbents is an effective strategy for the deep removal of SO2 from flue gas.