CO2 - valuable material or climate killer?

If we rely solely on emitting less CO₂, we are likely to miss the climate target aimed for in the Paris Agreement. But there are technical solutions to filter CO₂ out of the atmosphere. What is possible, where are the obstacles? The experts at the 4th Dialogue Forum 2021 of the series "Small things, big effect" gave an insight into this.

According to the Federal Environment Agency, the global concentration of carbon dioxide (CO₂) has increased by a good 44 percent since the beginning of industrialisation, which contributes to global warming. Therefore, Germany has set itself the goal of roughly halving CO₂ emissions by 2030 compared to 1990. By 2050, the aim is to be largely greenhouse gas neutral. A start has been made with the expansion of renewable energies and greater energy efficiency. But experts, such as those from the German Academy of Science and Engineering acatech, believe that Germany must continue to develop the use and storage of CO₂ with the help of so-called CCUS technologies (Carbon Capture, Usage and Storage) as climate protection options in order to meet the 1.5 degree target. Merely reducing emissions will not achieve the target. 

Carbon dioxide as a valuable raw material

"We have emitted unimaginably large amounts of CO_2. Capturing it from the air is essential to achieve the global climate goals," Christoph Beuttler from the company Climeworks is convinced. It is one of the world's leading companies for removing CO₂ from the atmosphere. The carbon dioxide extracted with the help of container-sized "hoovers" can either be completely removed from the air through storage (CCS) or reused as a raw material (CCU).

Dr. Doris Hafenbradl, managing director of Electrochaea GmbH in Planegg near Munich, for example, has a use for the extracted CO_2. The start-up has developed a power-to-gas technology that uses electricity from renewable energy and microorganisms to convert CO₂ into methane. The methane can then be fed directly into the gas grid. "We can use our process as a storage technology, where green electricity is converted into gas and stored in the gas grid. If needed, this process can then be reversed," she explained. Or you can use the gas in the conventional way for heating or cooking. In the end, it doesn't matter where the CO₂ comes from: whether from landfills, biogas plants or the cement and steel industry. 

Incentives for CO₂ avoidance

"CO₂ utilisation can be an entry hatch for ambitious climate protection pathways. But financial incentives should always be directed at the avoidance or extraction of CO₂ and not at its use per se," Prof. Sabine Fuss, head of the working group Sustainable Resource Management and Global Change at the Mercator Research Institute on Global Commons and Climate Change (MCC) in Berlin, therefore demands. It makes a big difference whether the CO₂ comes from the atmosphere or from coal-fired power plants and how the necessary electricity is generated. "It also depends on how long-lasting the product is," says Fuss. Because a synthetic fuel quickly releases the bound CO₂ back into the atmosphere. Therefore, one has to look carefully when it comes to CCU as a climate protection measure.

"The idea to create something great out of the ugly climate gas is of course very attractive," added Dr. Barbara Olfe-Kräutlein from the Institute for Advanced Sustainability Studies in Potsdam. Also because the products such as fuels, plastics, chemicals, fertilisers or proteins for food are so diverse. That is why one cannot give a general answer about the sense or nonsense of CCU technology, but must look at each application individually. "If the goal is to become carbon-negative, then you have to remove it from the atmosphere." If, on the other hand, one limits oneself to CO₂ reduction alone, other sources are also possible. 

Costs will decrease

The big question is how economic viable such processes are. So far, Beuttler says, the cost of $600 to $800 per tonne cannot compete with the market price of fossil CO_2. "We are at the beginning of the technology and expect to move into the $100 per tonne range over time."  He also said, there are customers who are quite willing to pay higher prices for CO₂ extracted from the atmosphere for marketing reasons already today. And costs aren’t the decisive argument if the alternative is to miss the climate targets.

Incentives could be provided by pricing CO₂, whereby, according to climate scientist Fuss, it is necessary to refer to the CO₂ avoided or removed from the atmosphere and not to the amount used. In the longer term, it would make sense to incorporate CCUs into the emissions trading system. "Ultimately, you always have to look at CCU promotion holistically”, she noted. Certain technologies only make sense if the energy sector is decarbonised fast enough. Therefore, she said, a cross-sectoral climate protection plan is necessary, and one must measure exactly how much CO₂ can be avoided with which measures.

"We have benefited from the funding opportunities in Germany and Europe to develop our power-to-gas technology," Hafenbradl admitted. With the start of the commercial phase, however, it becomes more difficult, she said, because the technology has to be deployed on a large scale for it to have an impact. "There we hope that not everything has to be checked down to the smallest regulatory detail first, but that incentives are created, for example as in California, to quickly reduce the CO₂ footprint of landfills or biogas plants with our process."

Counteract irrational fears

Olfe-Kräutlein is convinced that the broad spectrum of the funding landscape shows that politicians have recognised the potential of CCU technology and that it is by no means just a bridge to CCS. However, she pointed out that the storage of CO₂ met with little social acceptance in Germany. Irrational fears of leaks or the danger of earthquakes are difficult to overcome. "However, a change in thinking is also taking place here, so that as soon as the topic becomes more relevant again, we can work towards an objective assessment of the process." The situation is different with CCU technologies, which are hardly known among the population, but when they are, they meet with a positive response.

"We should be aware that there are no perfect solutions," Beuttler made clear. "But we also know that we will miss the climate targets if we do not remove CO₂ from the atmosphere at a large scale." And because it is a highly complex topic that is not suitable for the dinner-table talk, one should trust the experts. "It's not a question of wanting to, but we have to get going now," he appealed, adding: "We have the opportunity to turn the tide with CCUS technologies and less CO₂ emissions. This is our last chance to tackle climate change." 

The next Dialogue Forum will take place on 20 May 2021 on the topic of "5G, wireless networks and infrared - invisible radiation, invisible enemy?". 

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20. April 2021