Porous solid inspired hyper-crosslinked polymer liquids with highly efficient regeneration for gas purification

Separation media that combine the desired material properties within a single material for a given process remain an ongoing challenge for the gas separations in industry. Process integration of porous solid adsorbents is difficult due to their limited volumetric capacity, whereas issues of volatility and high regeneration temperatures exist for liquid amines and physical solvents. Herein, we report a family of polymer liquids inspired by hyper-crosslinked polymers (HCPs), a class of highly swellable network polymers. Compared with a chemically similar porous solid, the HCP-liquids demonstrate good volumetric capacity and improved selectivity of carbon dioxide over methane. Uptake appears to be enhanced by intramolecular swelling of the HCP-liquids at elevated pressures, while guests are strongly rejected from the HCP-liquids at slightly elevated temperatures, leading to highly efficient regeneration. Heat of adsorption and specific heat capacity of the HCP-liquids are also low, further suggesting favourable process thermodynamics. Additionally being easily prepared at scale, the presented HCP-liquids represent a promising step towards a material with the requisite properties to replace conventional scrubbing solvents to drastically reduce the footprint and energy needs of gas separations.