Why is carbon to be captured and stored?
CO2 can be captured by treating flue gas with a liquid. This takes place in a kind of filter called a scrubber. Here the gas is washed with the liquid, the liquid being poured over a structure with a large surface as the gas passes by. The CO2 dissolves in the liquid and thus the gas is purified.
There has been increasing interest in carbon capture since the UN’s Climate Change Panel announced in 2018 that carbon capture is unavoidable if we are to limit global warming.
The level of CO2 in the atmosphere is at its highest since the 19th century due to the combustion of fossil fuels. There is general agreement that atmospheric CO2 is the main cause of global warming.
The vast majority of countries have acceded to the Paris Agreement, which means the temperature increase must be kept to below 1.5 degrees C. For this to be realistic, current emissions of CO2 and other greenhouse gases must be stopped.
The Danish Government has therefore undertaken to meet a climate goal of reducing carbon emissions by 70 per cent by 2030, and emissions must be zero by 2050.
Research and further development of carbon capture utilization and storage are essential in achieving these goals.
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How far has Denmark come with carbon capture?
Towards 2030, Denmark will primarily be reducing emissions by capturing and storing CO2 underground. The reason is that carbon capture and storage is an existing technology that is now to be tested and scaled up. DTU contributes to this development.
For example, DTU has developed a mobile plant that can capture CO2 from biogas plants and power plants and acquire important operational experience. One of the challenges is to reduce energy consumption so that carbon capture does not become expensive. Therefore, one of DTU’s research areas is how to compose the chemical liquids used to capture CO2 and how to use heat pumps, etc. to minimize energy consumption. Research is also being conducted into how carbon capture can be linked in an integrated energy system.
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How far has Denmark come with carbon storage?
On the carbon storage side, there is experience from abroad. The Geological Survey of Denmark and Greenland (GEUS) is therefore cooperating with DTU to establish the technical potential for carbon storage in the Danish underground.
Calculations from GEUS have shown that the underground can probably contain up to 22 billion tonnes (GT) of CO2. This is equal to between 500 and 1000 years of the total Danish emissions at the current level.
How far has Denmark come with carbon utilization?
The technologies for using and utilizing CO2 to produce, for example, green fuels are not yet so developed that they can contribute with significant reductions. Therefore, carbon utilization is a research area for DTU.
An example of carbon utilization is that electrolysis can be used to convert power from wind turbines and solar cells into green hydrogen, after which gases and liquid fuels can be produced by adding carbon from CO2 to the hydrogen (Power-to-X).
Research will help ensure that Denmark is ready for carbon utilization as a resource towards meeting the climate goal of being carbon neutral by 2050.