Environmental effects

There are several environmental challenges related to CCS that need to be addressed and solved. There should not be any negative environmental impacts from CCS provided that impact studies are performed to determine all possible consequences and standards are established to designate how to operate CCS projects.

There is one very big positive effect of CCS: It reduces CO₂ emissions.

The potential to reduced CO₂ emissions is large. In fact, one-third of the global CO₂ emissions can be reduced by CCS by 2050 according to a Bellona Study.

This positive environmental effect of CCS overshadows the possible negative effects listed above, provided that the possible negative effects are properly addressed by all stakeholders.

CO₂ capture is often performend in absorption processes with amines. Portions of the amines will degrade, leading to large volumes of degraded amine that must be handled as hazardous waste.

Other capture processes uses ammonia as the absorbent. This can lead to minor emissions of ammonia.

The CO₂ stream to be injected should consist of overwhelmingly CO₂. No other components should be added to the CO₂ stream to be injected because it could potentially pollute the underground with hazardous wastes.

The stream coming out of a CO₂ capture plant should also be properly cleaned so that other components, like sulphur, nitrous components, metals, and particles, are removed prior to the CO₂ injection.

As an example of the importance of only injecting overwhelmingly CO₂ it can be mentioned that if mercury is injected together with the CO₂, the mercury can migrate over much larger distances underground than CO₂. That means that even if CO₂ is safely stored, mercury could migrate for long distances and, in the worst case, contaminate natural resources like fresh ground water.

If the stored CO₂ leaks out, the CO₂ can harm local terresteral and marine ecosystems close to the injection point. If huge volumes burst out, the CO₂ can replace oxygen leading to lethal conditions.

The good news is that it is possible to avoid CO₂ leakage and ensure safe storage.

However, there are many challenges related to CO₂ storage that must be addressed:

• Standards must be developed for characterization of possible storage sites.
• Standards must de defined for selecting storage sites.
• Equipment must be further developed for monitoring the injected CO₂.
• Studies must be performed to determine the consequences of CO₂ leakage.
• Remediation actions must be developed to deal with a leakage should it occur.

• Safe CO2 storage
• CCS challenges