An overview on trace CO₂ removal by advanced physisorbent materials

Area of Science:

• Chemical Engineering
• Materials Science
• Environmental Science

Background:

• Traditional liquid amine-based carbon capture (C-capture) is energy-intensive and not economically viable for widespread use.
• Existing physisorbent materials like MOFs and zeolites show promise but lack sufficient selectivity for trace CO2 levels.
• There is a critical need for innovative C-capture technologies that improve cost-effectiveness and environmental impact.

Purpose of the Study:

• To review advancements in physisorbent materials for efficient carbon dioxide (CO2) capture.
• To highlight key performance parameters for selecting suitable CO2 selective physisorbents.
• To discuss the potential of hybrid ultra microporous materials (HUMs) for CO2 capture.

Main Methods:

• Literature review of gas processing technologies and separation mechanisms (absorption, adsorption, distillation).
• Analysis of existing and emerging physisorbent materials, including MOFs, zeolites, and HUMs.
• Evaluation of material performance based on selectivity, regeneration energy, and applicability in complex gas streams.

Main Results:

• Physisorbents offer lower regeneration energy compared to liquid amines.
• Current MOFs and zeolites exhibit insufficient selectivity for trace CO2 removal (~1%) from natural gas streams.
• Hybrid ultra microporous materials (HUMs) demonstrate high selectivity and effectiveness in challenging separations, including humid gas streams.

Conclusions:

• Physisorbent materials, particularly HUMs, represent a promising avenue for developing more economical and environmentally sound CO2 capture technologies.
• Further development of CO2 selective physisorbents is crucial for addressing environmental concerns and economic viability in gas processing.
• HUMs show significant potential for gas sweetening and CO2 capture from complex, humid gas mixtures.