Norwegian researchers pioneer CCS process for post-combustion CO2

RESEARCHERS from SINTEF have developed a “simpler” low-cost carbon capture and storage (CCS) system for sequestering post-combustion CO2.

The Continuous Swing Adsorption Reactor (CSAR) builds on previous work from the Norwegian research organisation and has been found to be less energy intensive than other CCS processes, including monoethanolamine (MEA) and swing adsorption reactor cluster (SARC).

Jan Hendrik Cloete, a research scientist at SINTEF, said: “Our studies have shown that the CSAR technology competes very well with other technologies that utilise heat.

“This applies in particular if reasonably priced electricity from renewable sources is available.”

Competitive technology

Post-combustion CCS is typically achieved via chemical absorption, where CO2 is absorbed into a separation tower using a solvent and then regenerated in a high-temperature recovery column.

Despite being the most commercially used method, chemical absorption has drawbacks due to thermal regeneration requiring a lot of energy.

CSAR technology uses two reactors for the capture process. The first reactor involves adsorption, where a sorbent is used to bind to the CO2, separating it from the flue gas.

“This binding process occurs at low temperature and generates heat, which is then transferred to the other reactor, where it is used to release the CO2 from the sorbent, this time at a higher temperature,” explains Cloete.

A heat pump transfers heat between the two reactors and a vacuum pump is used to help release CO2.

SINTEF says that the use of these pumps makes the transfer of heat “very efficient”, as the process only needs to be operated using a single source of electricity, while plants do not need to go through extensive retrofitting to accommodate the technology.

Pilot success

Earlier this year, the CSAR method was trialled in partnership with CCS company Caox at the BIR AS waste combustion plant in Bergen, Norway.

BIR processes around 220,000 t/y of household waste and generates around 250,000 t/y of CO2.

After 100 hours of operation, SINTEF were able to replicate its lab-scale CCS on an industrial scale, using a pilot reactor designed to capture 100 kg/d of CO2.

SINTEF and BIR are continuing in its collaboration with Caox, having already designed a pilot plant that will be able to capture 3 t/d of CO2.

It is also working with a cement factory in Spain to deploy another pilot project as part of the EU-funded CAPTUS project.