A new scientific publication based on research from the AURORA project has just been released in the journal Industrial & Engineering Chemistry Research. This study delivers an in-depth analysis of the degradation behaviour of the CESAR1 solvent —a popular choice for solvent-based post-combustion CO₂ capture.

This work, developed under the AURORA project, supports the ongoing qualification and optimization of CESAR1 — a widely studied, non-proprietary solvent blend of AMP (2-amino-2-methylpropanol) and PZ (piperazine) — for long-term, commercial-scale deployment in industrial CO₂ capture applications.

📄 Title: Degradation of 2-Amino-2-methylpropanol and Piperazine at CO₂ Capture-Relevant Conditions 
🧪 Authors: Vanja Buvik, Kai Vernstad, Andreas Grimstvedt, Karen K. Høisæter, Solrun J. Vevelstad, and Hanna K. Knuutila

Why Study Solvent Degradation? 

In carbon capture systems, solvents like CESAR1 absorb CO₂ from industrial exhaust before it reaches the atmosphere. But over time, exposure to heat, oxygen, and other gases or contaminants can cause the solvent to degrade — producing unwanted by-products, reducing performance, and potentially creating environmental risks.

To ensure carbon capture is not only effective but also safe and sustainable, we need to understand:

  • Which degradation products form.
  • How quickly the solvent breaks down.
  • How to manage these changes in real-world industrial conditions.

This study is a crucial step in answering those questions.

What Did the Researchers Do? 

The team exposed CESAR1 to two types of stress conditions: 

  1. Oxidative degradation – simulating exposure to oxygen in the flue gas 
  2. Thermal degradation – simulating high-temperature environments encountered during solvent regeneration or reclaiming

They used advanced chemical analysis to identify and quantify what compounds formed under each condition. 

What Were the Key Findings? 

  • A total of 48 degradation compounds were identified and measured in CESAR1.
  • 15 of these compounds had not been previously reported in CESAR1 research.
  • The solvent degraded faster as a blend than its two components (AMP and PZ) do individually — meaning chemical interactions in the blend accelerate breakdown.
  • Harmful by-products such as nitrosamines and nitramines were found to form even in the absence of nitrogen oxides (NOx).
  • Volatile compounds like ammonia, formaldehyde, and acetaldehyde were also detected — these can escape into the air or contaminate the captured CO₂ if not properly controlled.
  • The study confirmed that the most abundant nitrogen-containing degradation products in CESAR1 have now been identified.

Why This Matters for AURORA? 

This research directly supports the goals of the AURORA project by helping to:

  • Develop more targeted and efficient monitoring and control strategies for CO₂ capture plants.
  • Improve solvent maintenance plans, such as when and how to reclaim the solvent.
  • Guide environmental safety protocols to manage emissions and waste.
  • Ensure CO₂ product quality, especially when reuse or storage is planned.

Understanding solvent degradation is essential to making CESAR1 — and carbon capture more broadly — safe, cost-effective, and ready for full-scale deployment.

Authors:

  • SINTEF Industry: Vanja Buvik, Andreas Grimstvedt, Kai Vernstad, Solrun J. Vevelstad.
  • Norwegian University of Science and Technology (NTNU) – Department of Chemical Engineering: Hanna K. Knuutila.
  • Technology Centre Mongstad (TCM): Karen K. Høisæter.

Conclusion

This study provides essential knowledge about how the CESAR1 solvent degrades under realistic CO₂ capture conditions. By identifying key degradation products and their formation pathways, the research lays the groundwork for improved solvent monitoring, safer operation, and more efficient long-term use of CESAR1 in industrial settings. These insights bring the AURORA project one step closer to enabling the large-scale deployment of carbon capture technologies across Europe.