Carbon capture and storage (CCS) is high on the agenda as part of the solution to the world’s climate issues. There is general agreement globally that it will be required to meet the carbon emission reduction targets and the global warming mitigation aspirations of the Paris Agreement. Also in Denmark, the government has high expectations for CCS and anticipates a potential reduction of 4-9 million tonnes per year by 2030.

The Danish Waste Association has drawn up a strategy to make the Danish waste-toenergy sector carbon neutral by 2030 and for the sector to produce negative emissions beyond that. CCS is a major part of this strategy. A study carried out by Ramboll for the Danish Waste Association concludes that capturing CO2 from Danish waste-to-energy facilities is technically feasible, economically attractive and a realistic solution.

The Danish Council on Climate Change expects a carbon capture and storage cost of DKK 1,050 (€141) per tonne, of which carbon capture accounts for DKK 700 (€94) and DKK 350 (€47) covers transport and storage. Ramboll expects this cost to be reduced significantly for major waste-to-energy facilities in Denmark thanks to shared infrastructure, development of the technology and optimisation of the CCS energy use via the production of district heating. This is possible because the facilities are all connected to the Danish district energy systems where the waste heat can be utilised.

For transport and storage, there are many benefits of economies of scale. Ramboll has in various studies analysed the savings achieved by establishing a joint pipeline system for CO2 transport. By way of example it is noted that if the amount of CO2 is increased from 1 to 3 million tonnes, the cost per tonne transported in pipelines decreases by 50%, and if the CO2 is transported by ship to Norway, the North Sea or the UK, the cost decreases by 25%.

In Copenhagen, a new carbon capture partnership – Carbon Capture Cluster Copenhagen (C4) – was recently formed for the purpose of building up, sharing and exploiting knowledge about carbon capture and mapping the possibilities of joint solutions. The C4 partnership includes Denmark’s three largest waste-to-energy plants, two energy utilities, two district energy networks, two port operators and a wastewater utility (ARC, Vestforbrænding, ARGO, Hofor, Ørsted, VEKS, CTR, Copenhagen Malmö port and Biofos).

The partners in the cluster will potentially be able to capture up to 3 million tonnes of CO2 from their facilities annually, corresponding to 15% of the Danish CO2 reduction target of 70% by 2030.

A political strategy for CCS in Denmark is underway and expected to be presented by the Danish government before the summer. It should ensure good framework conditions for large investments in carbon capture.

“It only makes sense for waste-to-energy plants to invest in the technology if there is an offtaker for the carbon captured afterwards. Likewise, nobody will invest in the required transport and storage if the delivery of CO2 is not guaranteed. It is a chicken and egg situation,” says Nils Chr. Holm, who also emphasises that it is now urgent to determine who should be responsible for storage and for transport by ship and in pipelines.

“A value chain like this is complicated to navigate for both investors and companies. Therefore, we need a decision on who should do what, and the Danish state may even have to assume ownership of parts of the infrastructure,” Holm says, concluding that: “There is no doubt that carbon capture is part of the solution to tackling climate change. We should just use it in a smart way and in the right contexts. If applied at wasteto- energy facilities, it may not only eliminate the emissions of the sector itself, but also contribute to negative emissions or provide carbon to P2X solutions. In this way, carbon capture may create a new role in the wasteto- energy sector.”