Carbon capture and storage (CSS) plays a vital role in the fight against climate change. Learn how carbon is captured and stored and how it not only reduces CO2 but also removes it through negative emissions.
Ørsted’s power plants complement wind and solar energy to make sure the Danish society has a sufficient supply of district heating and green electricity. The emissions from the power plants can be captured, and by capturing and storing biogenic carbon, which is emitted when using straw and wood chips as fuel, a net removal of carbon from the atmosphere occurs.
At Ørsted, we’ll capture and store biogenic carbon at our Asnæs Power Station in Kalundborg in western Zealand that uses wood chips and our Avedøre Power Station in the Greater Copenhagen area that uses a straw-fired boiler. Our carbon capture and storage project is based on a 20-year contract with the Danish Energy Agency. Visit the project Ørsted Kalundborg CO2 Hub for more information.
Step 1 – Capturing the CO2
The first stage of CCS is to capture CO2 from flue gas that comes from the biomass-fired power plants at Avedøre and Asnæs Power Station. It is captured by standardized carbon capture units. These units are delivered by Aker Carbon Capture, a pure-play carbon capture company.
The CO2 capture units have a total capacity of 65 tonnes of CO2 per hour, and the carbon is captured through amine washing. CO2 is separated from the flue gas stream through a scrubbing process in which 90 % of the CO2 content in the incoming flue gas is captured.
When the CO2 gas has been captured by the capture units, it’s transferred to compressor and liquefaction units.
Learn more about the capture technology of CO2
Step 2 – CO2 compression and liquefaction
The liquefaction units compress and cool the carbon stream, which turns the gaseous CO2 into liquid form. This is done by a compressor with intercooling, where the generated heat is utilised for district heating or cooled, depending on the district heating demand.
The liquid CO2 is sent for intermediate storage in insulated pressurised tanks.
Step 3 – Intermediate CO2 storage
The third stage after CO2 capture, compression and liquefaction is intermediate storage of the liquid CO2 in pressurised tanks. Liquid CO2 is stored at 15 bar(g) and -26 °C.
The intermediate storage shall ensure that carbon remains in liquid form until the product is exported. The tanks are cylindrical steel tanks that are up to 30 m in length and 6.5 m in diameter.