Carbon capture: How waste incineration can become climate neutral

How is it done?

In a waste incineration plant, the greenhouse gases are mixed with the smoke that rises from the chimney. 

"We plan to use the flue gas CO₂ capture technology which is the most efficient and the most mature, namely amine technology," says Hølaas. 

This technology uses chemicals that bind to the CO₂ found in the flue gas, so that the smoke released from the smokestack is CO₂-free. Once the carbon is captured, it can be cooled and pressurised before being shipped away in liquid form.

"This is the same technology that will be used at Norcem's cement factory in Brevik and at the waste incineration plant at Klemetsrud in Oslo," Hølaas points out. 

Land-intensive capture plants and long-distance transport, but permanent storage

A carbon capture plant requires a lot of space, which is a challenge on an existing industrial site. The feasibility study carried out by Statkraft shows that there is no space for a carbon capture plant on the existing site of the Heimdal district heating plant, so adjoining areas need to be used. 

"Preliminary calculations show a land requirement of around 7,000 square metres. However, we are conducting good dialogue with Trondheim municipality to find the necessary space to be able to realise the project," says Hølaas.

Once the greenhouse gas has been removed from the flue gas, it will be transported from the carbon capture plant in pressurised, liquid form in tanker trucks to an intermediate storage facility. 

"The plan is to transport the gas 36 kilometres to an intermediate storage facility in Orkanger. We estimate that 21 trucks will be driven every day, each with 30 tonnes of CO₂," says Hølaas. 

From the port at Orkanger the carbon dioxide will be shipped to a receiving terminal at Øygarden outside Bergen. From there, it will be transported by pipeline into the North Sea and then pumped into porous rocks at a depth of over 2,500 metres. Denser rocks above the reservoir ensure that the gas does not leak out and end up in the atmosphere. 

The price will go down

There are several reasons why carbon capture and storage was not adopted on a large scale a long time ago. The biggest obstacles are high costs and technological challenges. 

"Our preliminary calculations show a total cost for capture, transport, intermediate storage and permanent storage of NOK 2,500–3,000 per tonne of CO₂. We expect this price will decrease over time. With an expected quota price for fossil emissions of NOK 2,000 per tonne of CO₂ in Norway in 2030 and income from biological allowances this will eventually become profitable," says Hølaas. 

All the same, he emphasises that the CCS project at Heimdal will need public funding if it is to be realised by 2030. The plan is to carry out a concept study until the autumn of 2024, assessing, among other things, access to available land, zoning, discharge permits, and a final concept for capture, transport, interim storage and permanent storage. 

"Assuming positive answers from the concept study, we will continue the development and maturation of the project until the final investment decision in the summer of 2027," says Hølaas.