Tailoring the Pore Size and Chemistry of Ionic Ultramicroporous Polymers for Trace Sulfur Dioxide Capture with High Capacity and Selectivity

Abstract

Here we demonstrate the deep removal of SO2 with high uptake capacity (1.55 mmol g−1) and record SO2/CO2 selectivity (>5000) at ultra‐low pressure of 0.002 bar, using ionic ultramicroporous polymers (IUPs) with high density of basic anions. The successful construction of uniform ultramicropores via polymerizing ionic monomers into IUPs enables the fully exploitation of the selective anionic sites. Notably, the aperture size and surface chemistry of IUPs can be finely tuned by adjusting the branched structure of ionic monomers, which play critical roles in excluding CH4 and N2, as well as reducing the coadsorption of CO2. The swelling property of IUPs with adsorption of SO2 contributed to the high SO2 uptake capacity and high separation selectivity. Systematic investigations including static gas adsorption, dynamic breakthrough experiments, stability tests and modeling studies confirmed the efficient performance of IUPs for trace SO2 capture.

Chemical immobilization of amino acids into robust metal–organic framework for efficient SO2 removal

“…The increasing energy demands resulting from the booming economy and population growth have resulted in the massive consumption of fossil fuels, 1–3 leading to the emission of a large amount of acid gas emissions including sulfur dioxide (SO 2 ), and have consequently aggravated the air pollution 4 . Typical flue gases discharged from coal‐based fire plants contain a SO 2 concentration between 500 and 3000 ppm, the trace SO 2 can significantly reduce the performances of amine‐based CO 2 scrubbers and irreversibly poisons the noble catalysts in the subsequent NO X reduction and CH 4 combustion 5,6 . The existing flue gas desulfurization (FGD) technique, that is, wet scrubbing, needs to be optimized in order to reduce the energy and water consumption and minimize the amount of unmanageable waste produced.…”

Feasible bottom-up development of conjugated microporous polymers (CMPs) for boosting the deep removal of sulfur dioxide

“…[3][4][5][6] Compared with conventional wet and dry ue gas desulfurization processes such as alkaline slurry scrubbing and lime spray drying, reversible physical adsorption via porous materials such as zeolites and activated carbon is recognized as a sustainable energy-saving technology for SO 2 removal. [7][8][9][10] However, SO 2 and CO 2 are both acidic gases and have similar kinetic sizes (0.4 nm for SO 2 vs. 0.33 nm for CO 2 ), making the selective adsorption of SO 2 over CO 2 full of challenges.…”

Synthesis of Guanidinium-Based Poly(ionic liquids) with Nonporosity for Highly Efficient SO2 Capture from Flue Gas

“…Recently, ionic liquids (ILs) have been popularly considered as novel and efficient solvents for gas absorption because of their excellent ability for selective molecular recognition. , So far, a lot of ILs have been reported and used for efficient capture of SO 2 and CO. − For example, Xing et al prepared a kind of nonporous imidazolium-based poly­(ionic liquid) xerogel, which showed large SO 2 adsorption capacity (7.78 mmol g –1 ) and high selectivity of SO 2 /CO 2 (up to 614) via a swelling mechanism but excluded the adsorption of CO 2 and N 2 . However, such nonporous poly­(ionic liquids) need a complex preparation process involving microfluidic technology and photopolymerization, and the column breakthrough performance is also not satisfied entirely.…”