Microwave swing regeneration of aqueous monoethanolamine for post-combustion CO2 capture

- Microwaves can regenerate CO2 rich MEA solution quickly and at 70-90 °C.
- Microwave regeneration can reduce energy penalty, corrosion, amine degradation.
- Microwaves regeneration presents a special 'non-thermal' effect.
- Fast regeneration can reduce the size of a capture process.

Post-combustion carbon capture is a key component of the fight against global warming and climate change. Amine stripping is currently the leading post-combustion technology, and indeed is employed at the World's first and only commercial scale carbon capture project applied to a power plant, at Boundary Dam, Canada. Normally, regeneration of the spent amine solution is achieved by stripping with hot pressurized steam, at around 120-140 °C and 1-2 bar. However, production of these conditions is costly and leads to significant degradation of the amine. Moreover, the size of equipment, and hence capital costs, are also high due to the regeneration timescales involved. Here, we present proof-of-concept laboratory scale experiments to demonstrate the feasibility of regenerating the spent amine solution with microwave irradiation. We show that microwaves can regenerate spent aqueous monoethanolamine solutions quickly and at low temperatures (70-90 °C), potentially reducing overall process costs. By comparing microwave regeneration with conventional thermal regeneration we suggest that, in addition to the usual benefits of microwave heating, microwaves present a special 'non-thermal' effect.