29.06.2023

Returkraft is testing out membrane technology with support from CLIMIT

Yet another pilot has started testing of carbon capture on real flue gas from an industrial plant. Returkraft’s waste incineration plant in Kristiansand is testing Air Products’ membrane technology.

There is a great deal of excitement around the results of the project, as this knowledge may be beneficial for other incineration plants.

The pilot is integrated into the plant

“It will be exciting to see how Air Products membranes will manage capturing CO₂ from an incineration plant,” says Jørild Svalestuen, Senior Advisor, CLIMIT, on her way to Kristiansand.

Testing Air Products commercial membranes on waste gas from an industrial facility has never been done before. The membranes are typically used to separate methane and CO₂ in biogas plants, for example. It will also be an important step for Air Products if these membranes can also be used at industrial facilities to remove CO₂ from off-gases. It will be particularly interesting to get knowledge on the capture rate and purity of the CO₂ (permeability and selectivity) in this pilot test.

“Returkraft started testing in May and has already run the pilot for several days. Everything is going according to plan,” says project manager Ketil Bergmann, adding that they are extracting the flue gas at a temperature of around 60 ⁰C, which seems to be going very well. “The membranes from Air Products are responding well to the flue gas and capturing of CO₂ is ongoing.”

For Returkraft, this pilot project is an important part of their plan to realise a full-scale capture facility in 2030.

Returkraft will gain valuable information both on the operation of the capture facility and integration with existing production. This information can be shared with others once the testing has finished.

Ketil Bergmann explains about the test pilot to Jørild Svalestuen.

Returkraft in brief

Returkraft’s incineration plant is located five kilometres from Kristiansand city centre and started operation in 2010 handling waste from Agder. The owners are made up of the municipalities in Agder, with Kristiansand and Vennesla being the primary owners (49%).

Returkraft handles a total annual amount of general waste and hazardous waste of approximately 130,000 tonnes. The energy from the waste incineration produces 95 GWh of electricity per year. In addition, 250 GWh

of district heating is being produced every year. Annual carbon emissions are around 140-150,000 tonnes of with approximately 55% is biogenic CO₂.

Kristiansand’s climate goals

Kristiansand Municipality has a goal of reducing its carbon emission by 80% by 2030. To meet this goal, Kristiansand’s largest emissions at source must contribute. Returkraft’s plant has 44 MW, of which 99% of the district heating goes to the citizens of Kristiansand. An advantage of this plant is that it will not be directly affected by being connected to a capture facility. There is already a possibility to provide a capture facility with both heat energy and cooling.

The piloting of CO₂ capture at Returkraft could influence how future plants are built. “It is really great,” says Jørild, “that CLIMIT support contribute to reduction of risks and carbon capture costs on the way to full scale CCS. We also want CLIMIT projects to share their experiences and knowledge as far as possible.” Returkraft and the largest waste-to-energy plants in Norway have taken the lead on this and are collaborating to make CCS a reality by sharing their respective experiences and knowledge (KAN – Klimakur for Avfallsforbrenning i Norge (Climate cure for waste incineration in Norway)).

Air Products in Kristiansand in brief

A part of the American company Air Products and Chemicals Inc. (APCI) and Air Products Prism Membranes (APPM), one of the world’s largest manufacturers of membranes.

Air Products is a Kristiansand-based company with long experience in the production of air separation units based on membrane technology. The company was originally founded to meet the needs for inert gas systems for ships but has more recently developed the technology for other uses, such as carbon separation (cf. pilot studies with NTNU’s CO₂ membrane technology licenced to Air Products at Norcem, Brevik). Carbon capture is currently one of Air Products focus areas using membrane qualities Air Products has long experience with. Air Products in the United States are developing new membrane-based capture concepts.

Planning the next phase towards CCS

Ketil Bergmann is clear that the ball must get rolling if they are to achieve their goal of operating a capture facility by 2030. There is already ongoing work to get the next phase of the plan towards 2030 in place. Bergmann emphasises that the KAN cooperation is helpful. KAN consists of the five largest waste-to-energy plants in Norway. All having their own ongoing CCUS projects and by working together they will find the best possible frameworks and solutions for CCS on waste-to-energy.