Why carbon dioxide storage makes sense

To limit climate change, the global transition in energy production – away from fossil fuels and towards renewables – is crucial and takes precedence over all other measures. However, it is also necessary to develop technologies for CO₂ capture and storage, says Detlef Stolten, Head of the Institute for Techno-Economic Systems Analysis (IEK-3) at Forschungszentrum Jülich.

“In the long term, the transition to greenhouse gas neutrality, as set out in the German Climate Protection Act, will not be sufficient to achieve the climate targets,” says Detlef Stolten, Head of the Institute for Techno-Economic Systems Analysis (IEK-3) at Forschungszentrum Jülich. Analyses by the IPCC have shown that, by around 2060/2070 at the latest, CO₂ would have to be actively removed from the atmosphere in order to achieve greenhouse gas neutrality. Furthermore, it would be very costly to avoid the “last tonnes of CO₂”, for example in the chemical industry or in aviation. In these cases, carbon capture and storage (CCS) represent more cost-effective alternatives – as demonstrated by analyses carried out by IEK-3 at Forschungszentrum Jülich. However, this only applies to emissions that are difficult to capture or to basic chemicals that are difficult to replace.
Furthermore, some CO₂ emissions are unavoidable due to chemical reactions during material conversion in production, particularly in cement, quicklime and glass manufacturing.
Furthermore, the expert in techno-economic system analysis points out that certain interim targets for the energy system transition are unlikely to be met on time. Gas-fired power stations, which are intended to back up renewable energy sources during periods of low wind or sunshine, will, for example, not be equipped with a hydrogen supply in time. It should therefore be permitted, on a temporary basis, to operate them using natural gas. Such transitional arrangements should, however, be subject to clear phase-out rules or corresponding costs.
How can CO₂ capture and storage be achieved? CO₂ can be captured and stored biologically through afforestation and the restoration of peatlands, as well as through the use of biomass followed by capture and storage. At specific, i.e. large, and as constant as possible energy consumers, CO₂ can be captured after the combustion process using tried-and-tested techniques. Another new technology, which Helmholtz in particular is researching, is Direct Air Capture (DAC). DAC makes it possible to capture CO₂ directly from the air.
In the Helmholtz project DACStorE, researchers are investigating fundamental processes, developing new capture methods, designing plants, identifying potential sites worldwide for future operation, and identifying and evaluating storage sites. Particular emphasis is placed on the safety of storage sites, for example through close monitoring. These technologies could fill the gap described above.
According to Stolten, it is to be welcomed that the German government’s carbon management strategy focuses on hard-to-avoid and unavoidable emissions and the transition to renewable energies. The task now is to address the long-term perspective in a separate strategy.
Source: Helmholtz Association of German Research Centres