When CO2 is captured from flue gases released from industrial sources, a substance that binds CO2 is utilized. The most used substance today are amine solvents. This technology is, for example, used at the cement factory in Brevik and will also be installed at the waste incineration plant at Klemetsrud in Oslo.
For successful implementation of carbon capture, it is crucial that the amine solvent is stable. This new report addresses various factors that affect the stability of the capture medium. The report is made by SINTEF in collaboration with NTNU, as part of the international research collaboration on carbon capture and storage, NCCS.
Many alternatives on the market
There are many alternatives amine solutions on the market. Therefore, it is important to know whether the solvent or technology supplier has conducted the important and correct tests. With the information package provided with this report, it will be easier to understand the various aspects of amine stability.
The report is intended to be a tool for industrial players who want to capture CO2, but also for suppliers, authorities, and other stakeholders. It provides an overview of various factors to consider so that the capture plant can be operated in the most efficient, risk-free, environmentally friendly, and economically profitable way.
"Safe and wise choices are crucial when it comes to solvent technology. Having control over what happens with the solvent in the process over time will make it easier to operate the plant efficiently and economically. This can involve impacts on operation, affecting the efficiency or functionality of the amines, or environmental impacts," says SINTEF researcher Vanja Buvik.
Facing a tough environment
In the carbon capture process, CO2 is first bound at low temperature and then separated out at a high temperature. In the process, the amines should be as stable as possible, but this is not obviously easy to predict or ensure. The conditions faced by the amines are challenging, including heating to just over 100°C when releasing the pure CO2 and exposure to various substances and conditions that can trigger reactions.
"Among other things, industrial gases contain oxygen, which also can react with the amines to form compounds that cannot capture CO2, resulting in a loss of capture capacity. Different amines also have varying tendencies to oxidise, making it crucial to determine the exact oxidation resistance of the amine you intend to use in your process, " Vanja Buvik explains, adding:
"High temperatures and the presence of certain metals can also significantly accelerate the oxidation process, but high temperatures alone can also be a direct cause of the amines breaking down. In addition to testing their resistance towards the tough process conditions, it is also important to test the stability of the amines in contact with nature:
"If the amines were to be released into the environment, it is important to know that they will not cause harm to humans or other organisms. Ideally, we want the amines to be biodegradable and not give rise to any negative effects on the environment and safety. This is important both for the local environment and for those working at the capture plant." Buvik explains.
Read the full report "Information package for assessment of new amine solvents"
