A recent innovation has the potential to accelerate the introduction of essential carbon capture processes across a range of industries. The technology has been recently demonstrated at a waste combustion plant in Bergen, Norway, yielding excellent results.
Industrial plant flue gases contain the greenhouse gas CO2. Carbon capture processes increase the concentration of the gas, enabling it to be used or stored.
However, carbon capture technologies rely on energy to release the CO2 after it has been captured. This process typically uses heat as its energy source, and some industries can exploit available surplus heat. For others, however, carbon capture requires complex retrofitting or modifications to infrastructure, which incurs increased fuel costs.
Optimising energy consumption
A team of researchers at Stiftelsen for industriell og teknisk forskning (SINTEF) has recently developed a new and simpler technology for capturing CO2 from industrial flue gases. It is called the Continuous Swing Adsorption Reactor (CSAR) and is based on a heat pump, a vacuum pump and the efficient use of electricity.
“Our studies have shown that the CSAR technology competes very well with technologies that utilise heat,” a spokesperson at SINTEF said. “This applies in particular if reasonably-priced electricity from renewable sources is available.”
The advantage is that both pumps require only a single conventional source of electricity, making the technology ideal for installation in existing plants. Jan Hendrik Cloete, a Research Scientist at SINTEF, explained the process in more detail.
“The CSAR technology utilises two reactors in the capture process. The CO2 is initially captured in the first reactor by a sorbent, which binds the gas to its surface. This binding process occurs at low temperatures and generates heat. The heat is then transferred to the other reactor, which releases the CO2 from the sorbent at a higher temperature. The heat pump is used to transfer the heat between the reactors, while the vacuum pump assists in releasing the CO2. The combined action of the two pumps makes heat transfer very efficient, which is also why this technology uses low amounts of energy.”
Highly competitive
“Our studies have shown that the CSAR technology competes very well with other technologies that utilise heat,” Mr Cloete said. “This applies in particular if reasonably-priced electricity from renewable sources is available..”
Earlier in 2024, SINTEF and the Norwegian company Caox demonstrated the CSAR technology at the BIR AS waste combustion plant outside Bergen. Every year, BIR processes about 220,000t of household waste for electricity and district heat generation, emitting 250,000t of CO2.
“After 100 hours of operation, we found that we were able to capture the same amount of CO2 from real exhaust gases as we had in our laboratory tests”, Mr Cloete said. “This was an important step because it confirmed that the CSAR concept also works at an industrial scale. It also helped to boost confidence in our economic estimates.”
The pilot reactor is designed to capture 100kg of CO2 per day. By 2030, BIR plans to install a facility that will capture 100,000t of CO2 annually. This will be achieved using commercially available technologies. At the same time, the company is also considering using new and more efficient technologies, such as CSAR, to capture the remaining CO2.
Contributing to CCS technology development
Results from the BIR plant in Bergen are paving the way for scaling up the CSAR technology for application across a range of industries. The pilot reactor has now been returned for upgrading at SINTEF’s multiphase laboratory in Tiller outside Trondheim.
The pilot will then be installed in a cement factory in Spain. This is part of an ongoing EU-funded project called CAPTUS, which investigates sustainable methods for capturing and utilising CO2 from energy-intensive industries.
Image: Ratchapon/stock.adobe.com
