The challenge:

During chemical absorption CO₂ present in a flue gas is absorbed and chemically bound to a solvent. The reaction is reversed during solvent regeneration and the solvent is reused to absorb CO₂. Tiny amount of the solvent will react with other compounds in the flue gas forming compounds that cannot be regenerated. Over time these reactions lead to loss of capture efficiency and could cause problems as corrosion, fouling, foaming and increased emissions.

The innovations:

The work in NCCS investigates several mitigation methods including:

• Identification of solvents with higher chemical stability to minimize solvent loss
• Mitigation technologies, like removal of oxygen from the solvent as these components will enhance degradation
• Better understanding the degradation and corrosion mechanisms, allows development of innovative, new technologies to tackle the challenges

Potential impact:

Base case for illustration: 2MTPA CO₂ captured from 2 CGCC power plants using 30% MEA-based solvent technology. Two viable strategies for controlling degradation:

• New technology enabling 50% reduction in solvent degradation gives potential savings up to €4M/year in solvent make-up cost
• The make-up cost is reduced by factor of 16 by switching to a solvent which is 2.5 times more expensive but degrades 75% less than MEA