Harvesting Electrical Power during Carbon Capture using Various Amine Solvents

Area of Science:

• Environmental science and engineering
• Electrochemistry
• Chemical engineering

Background:

• Urgent need for technologies to mitigate climate change by reducing and capturing carbon dioxide (CO2) emissions.
• Carbon capture reverse electrodialysis (CCRED) offers a novel approach by harvesting energy from CO2 capture processes.
• Existing CCRED systems often require freshwater, limiting their industrial applicability.

Purpose of the Study:

• To compare the maximum power densities of Carbon Capture Reverse Electrodialysis (CCRED) using various carbon capture (CC) solvents.
• To evaluate the feasibility of a semiclosed CCRED system utilizing industrial emissions and heat.
• To identify the most effective CC solvent for maximizing energy generation in CCRED.

Main Methods:

• Investigated five common CC solvents: monoethanolamine (MEA), diethanolamine (DEA), N-methyldiethanolamine (MDEA), 2-amino-2-methyl-2-propanol (AMP), and ammonia.
• Operated a semiclosed CCRED system, taking industrial emissions and heat as inputs.
• Measured the maximum power densities achieved for each solvent under operational conditions.

Main Results:

• The highest power density achieved was 0.94 W m^-2 cell^-1, utilizing ammonia as the CC solvent.
• CCRED with ammonia demonstrated superior energy harvesting capabilities compared to other amines tested.
• The semiclosed system successfully converted inputs into electrical power, clean emissions, and captured CO2.

Conclusions:

• Ammonia is a highly effective solvent for CCRED, significantly enhancing energy generation efficiency.
• The developed semiclosed CCRED system provides a pathway for incentivizing carbon capture technologies.
• This research lays the groundwork for advancing CCRED systems for practical industrial applications in climate change mitigation.