Carbon capture and storage, or CCS, is an umbrella term for a range of technologies that make it possible to remove CO2 from the air or from an emission source that would otherwise release it into the atmosphere. The term also includes the permanent storage of the captured CO2. Here, we explain how Hafslund's chosen technology works, why it is necessary, and Hafslund's role in developing solutions that will bring us closer to a zero-emission society.

Carbon capture technology in brief

Hafslund has chosen an amine-based technology. The state aid agreement requires participants in the Longship project to use mature technology.

• Separates CO2 from flue gas.
• Uses a chemical solution known collectively as amines to separate CO2 from the flue gas.
• Using pressure and temperature, the CO2 is compressed into liquid form before transport and storage.
• Carbon capture is a key technology for reducing emissions in sectors that cannot be electrified, such as the production of cement, fertilizer and steel, and especially waste incineration.

What is carbon capture technology?

Carbon capture technology encompasses processes that separate CO2 from flue gas before it is released into the atmosphere. This makes the technology particularly important for sectors such as waste incineration, cement production, the metals industry, and certain parts of the energy sector—processes that generate CO2 emissions regardless of the energy source.

Electrification, renewable energy and energy efficiency are essential to a low-emission society, but they cannot solve everything. That is why the EU, the UN and the International Energy Agency all consider carbon capture a necessary part of the climate toolbox.

This is evident in the work on Oslo CCS – Hafslund's initiative for carbon capture at Klemetsrud – where the technology can remove large amounts of CO2 from waste incineration and help achieve significant emissions reductions by 2030. You can read more about the project on the Oslo CCS pages.

Capture, transport and storage – three parts of the same technology

Carbon capture technology involves more than just capturing CO2. The entire value chain consists of:

• Capture: CO2 is separated from flue gas or process gas.
• Transport: CO2 is compressed and transported in liquid form from the capture facility to a permanent storage facility.
• Storage: CO2 is permanently stored in geological formations deep underground or beneath the seabed.

If you would like to learn more about storage, the concepts are explained in more detail here: carbon storage and carbon capture and storage.

How does carbon capture technology work in practice?

The capture itself takes place by directing the flue gas into a dedicated facility that separates out CO2. The principle is simple: The technology must capture the CO2 molecules without disrupting the rest of the process.

In practice, this is done in three main steps:

1. CO2 is captured from the flue gas

The flue gas contains CO2, water vapor, and other naturally occurring components. When the flue gas enters the capture plant, it is cooled before being brought into contact with an amine solution in an absorber, where the CO2 is captured.

The amine solution containing CO2 is fed into a desorber, where the amine is heated so that the CO2 can be separated from the amine solution. The amine solution is filtered and reused. The gaseous CO2 is compressed, dried and sent for liquefaction. The gas is converted into liquid form at approximately 15 bar and -26 degrees Celsius.

2. Chemical or physical separation

Amine-based absorption – the most widely used technology

This method is also used at Hafslund’s carbon capture facility at Klemetsrud. The flue gas is scrubbed with a liquid containing amines, which bind to the CO2 molecules. When the liquid is heated, it releases the CO2 and can be reused. This provides a stable and well-documented capture process.

– The technology selected for our carbon capture facility at the waste incineration plant at Klemetsrud is mature, safe and flexible. The technology supplier has experience from operational facilities, enabling lessons learned from previous projects to be applied to ours. This contributes to industrial and technological development, says Truls Jemtland, Head of Communications at Hafslund Celsio.

3. Purification, cooling and compression

Once the CO2 has been separated, it is purified to remove impurities, cooled and compressed into liquid form. It can then be transported – for example by train, truck, ship or pipeline – for permanent storage in geological formations.

This is the same principle used in the national initiative in which Northern Lights will store CO2 beneath the North Sea.

Hafslund's role in the development of carbon capture

Hafslund plays a key role in Norway’s carbon capture efforts through the construction of Oslo CCS, the carbon capture facility at Klemetsrud. This project will become one of the country’s largest climate initiatives and an important reference project for the rest of Europe.

Once completed, the facility will be able to capture 350,000 tonnes of CO2 per year. This is equivalent to a reduction of approximately 20 percent of Oslo’s fossil fuel emissions. The experience gained from the project can also be applied to around 500 similar waste incineration plants across Europe, where waste must be managed safely and in a climate-friendly manner.