Hybrid Ultramicroporous Materials for low-concentration carbon capture and alkyne removal from olefines

Abstract

Development and implementation of novel and energy-efficient technologies to mitigate greenhouse gas emissions in the atmosphere, particularly CO2, is a vital step towards fossil fuel-based sustainable energy. Removal of greenhouse gases from dilute emissions has been identified as one of the seven chemical separations to change the world. Additionally, the requirement for long-duration human task performance in confined spaces such as submarines, spacecraft or underground citadels has made the removal of low-concentration CO2 (< 0.5%) a critical technology. Reducing energy consumption is another promising way to reduce CO2 emissions. The energy use for separation and purification processes accounts for 40 % of the total energy use in chemical industry. Especially, high-purity ethylene (C2H4) and propylene (C3H6), two most produced chemicals, inevitably contain low concentrations of acetylene (C2H2) and propyne (C3H4) during the production. Catalytic hydrogenation and solvent absorption are two main processes for alkynes removal but with high energy consumption and low removal rate. Thus, tremendous energy savings are expected by applying advanced adsorptive separation technologies based on porous materials. The key feature of these environmentally friendly, energy-efficient separation technologies is the porous adsorbent or porous media. Hybrid ultramicroporous materials (HUMs) with electronegative anion pillars lined up within the pore channels have been illustrated as promising adsorbents for gas separation and CO2 capture. Herein, HUMs with fine-tuned pore dimensions are synthesized via mechano-assisted method and used for efficient low-concentration carbon capture and alkynes removal from olefins via strong host-guest and guest-guest interactions.