It was controversial for a long time, but in view of the climate crisis, storing CO2 in the ground could celebrate a renaissance. How secure is the technology? And can it really contribute to climate protection?
By Marleen Wiegmann, tagesschau.de
Germany has made a commitment: the country should be climate-neutral by 2045. But emissions are not falling fast enough to meet that target. Researchers are therefore calling for CO2 to be reduced in other ways in addition to the savings. In Germany, a well-known technology could celebrate a comeback: Carbon Capture and Storage (CCS), in German: the separation and underground storage of CO2.
Economics and Climate Protection Minister Robert Habeck’s trip to Norway two weeks ago could be an indication of this. Because CO2 from Germany is to be transported to Norway in the future and stored there under the seabed. Before the end of this year, the federal government wants to develop a carbon management strategy and remove legal hurdles that are currently preventing the transport of CO2 to Norway.
Use of old natural gas fields
With CCS, CO2 from coal-fired power plants or cement plants, for example, is separated, liquefied and then transported to the storage site via pipeline, ship or truck. This can be in deep rock strata on land (on-shore) or under the seabed (off-shore). Old natural gas fields are also used to introduce the CO2, as gases have already been stored here for at least 10,000 years.
CO2 capture is currently being pursued primarily in industrial companies. There are various methods that start at different points in the industrial process. They either remove the CO2 before or after industrial processing or treat the air used for combustion.
Filtering it out of the atmosphere is currently still very expensive and energy-intensive. According to Habeck, CCS should be an interim solution for unavoidable emissions that cannot currently be avoided.
Use of old natural gas fields
With CCS, CO2 from coal-fired power plants or cement plants, for example, is separated, liquefied and then transported to the storage site via pipeline, ship or truck. This can be in deep rock strata on land (on-shore) or under the seabed (off-shore). Old natural gas fields are also used to introduce the CO2, as gases have already been stored here for at least 10,000 years.
CO2 capture is currently being pursued primarily in industrial companies. There are various methods that start at different points in the industrial process. They either remove the CO2 before or after industrial processing or treat the air used for combustion.
Filtering it out of the atmosphere is currently still very expensive and energy-intensive. According to Habeck, CCS should be an interim solution for unavoidable emissions that cannot currently be avoided.
Geologists believe technology is safe
But even today, when it is no longer about the life cycle assessment of coal-fired power plants, there is still criticism of CCS. Karsten Smid is Greenpeace’s climate and energy expert. Even ten years later, CCS is not an option for him. Rather, he fears that the CO2 could escape again through leaks and earthquakes.
Klaus Wallmann sees it differently. He has been researching CCS at the GEOMAR Helmholtz Center for Ocean Research in Kiel for years and is of the opinion: “We need CCS to curb climate change.” Many of his colleagues put it the same way. CCS is a means of becoming climate-neutral. This means that the amount of emitted and removed emissions balance out. This can happen, for example, through reforestation or technologies such as CCS. The Intergovernmental Panel on Climate Change therefore also includes CCS as a means of combating climate change.
