The illustration to the left (from SINTEF Energi) shows how the CO2 can be separated from gasified coal. The remaining hydrogen rich gas can be used in combustion, the emissions of which will then be largely CO2 free. While the project’s research centred on this case, minor adaptations to the method could also render it applicable to regular coal fired power plants as well as in industrial production of cement, iron and steel. Researchers estimate that the studied cooling solution can cut energy consumption and costs of CO2 capture with 30 per cent.
CCS in Europe faces a number of hurdles before roll-out, one of which is transport. Most capture technologies result in CO2 in gas form. Most discussions about transport therefore revolve around pipelines (the construction of which can be caught up protracted corporate and political decision making processes). The cooling method could reduce the immediate need for pipelines as it eases transportation by for example ship.
Researcher Kristin Jordal tells gemini.no: “CO2 that is captured in liquid form can namely be loaded directly on to ships and be transported to offshore storage sites, before pipelines are in place. Should our findings open for cold CO2 capture, it would contribute to the acceleration of CO2 storage in the North Sea.” The cooling method could also in the future be adapted to result in gaseous CO2 and thereby offer further flexibility.
The research team began looking at the capture option as part of the EU funded project DECARBit. Jordal explains that there were many who doubted that cooling would be cost and energy effective. “But when we got going, we showed that several process improvements are possible. Thereby cold CO2 capture came out amongst the most promising technologies,” Jordal said. There will be more research needed before the results are conclusive, but they are promising, especially considering some rather low initial expectations.
Read more (in Norwegian) here.
Read about recent progress being made in the EU on CCS here.