Moving beyond 90% Carbon Capture by Highly Selective Membrane Processes.

Area of Science:

• Chemical Engineering
• Environmental Science
• Materials Science

Background:

• Coal-fired power plants are major CO2 emitters, necessitating efficient carbon capture technologies.
• Facilitated Transport Membranes (FTMs) offer high CO2 selectivity for separating gases.
• Deep carbon capture is crucial for mitigating climate change in the energy sector.

Purpose of the Study:

• To evaluate a membrane-based system for achieving >90% carbon capture from coal flue gas.
• To compare the efficacy of retentate recycle and enriching cascade processes for carbon capture.
• To determine the techno-economic feasibility of deep carbon capture using FTMs.

Main Methods:

• Utilized a highly CO2-selective facilitated transport membrane (FTM).
• Implemented a membrane system with a retentate recycle process and an enriching cascade.
• Conducted a techno-economic analysis to assess capture costs and energy consumption.

Main Results:

• The retentate recycle process is cost-effective for ≤90% capture due to lower energy and membrane area requirements.
• The enriching cascade process is superior for >90% capture, enabling higher pressure ratios.
• A combined system achieved 99% carbon capture with a capture cost of $47.2/tonne.

Conclusions:

• FTM-based systems are effective for deep carbon capture from coal flue gas.
• Combining retentate recycle and enriching cascade processes optimizes deep carbon capture efficiency and cost.
• This technology can significantly contribute to carbon emission mitigation in the energy sector.