Nitrosamines and Nitramines in Amine-Based Carbon Dioxide Capture Systems: Fundamentals, Engineering Implications,...

Area of Science:

• Chemical Engineering
• Environmental Science
• Atmospheric Chemistry

Background:

• Amine-based absorption is a leading technology for post-combustion CO2 capture.
• Concerns exist regarding the formation and emission of toxic nitrosamine and nitramine byproducts from these systems.
• Understanding these byproducts is crucial for safe and efficient CO2 capture.

Purpose of the Study:

• To review current knowledge on nitrosamine and nitramine formation in CO2 capture systems.
• To analyze reaction mechanisms in different units (absorber, desorber, washwater).
• To discuss mitigation strategies and identify research gaps.

Main Methods:

• Literature review of CO2 capture, biological, and atmospheric chemistry studies.
• Analysis of reaction mechanisms for nitrosamine and nitramine formation.
• Discussion of factors influencing byproduct formation, such as amine structure and temperature.

Main Results:

• Nitrosamine and nitramine formation is driven by flue gas NOx in the absorber and high temperatures/nitrite in the desorber.
• Amine structure influences nitrosamine formation.
• Washwater units can inadvertently increase nitrosamine formation.
• Nitramines are less studied than nitrosamines.

Conclusions:

• Clarifying reaction mechanisms and developing analytical methods are critical research needs.
• Quantitative prediction of byproduct accumulation and emission requires integrated system analysis.
• Further research is needed to ensure the safety and viability of amine-based CO2 capture.