In addition to replacing fossil fuels with renewable energy sources and energy efficiency measures, the goal of climate neutrality requires further innovative solutions. Two additional key technologies in the area of CO₂ reduction are CCS (Carbon Capture and Storage) and CCU (Carbon Capture and Utilization). In contrast to the general avoidance of CO₂ emissions, they aim to bind existing or unavoidable greenhouse gases before they rise into the earth's atmosphere.
What is CCS - Carbon Capture and Storage?
CCS is a technology that aims to capture, transport and permanently store carbon dioxide (CO₂) directly at the source of emissions - for example in power plants or industrial facilities. The process consists of three main steps:
- CO₂ separationCO₂ is filtered out of the exhaust gases.
- TransportationThe captured CO₂ is transported via pipelines or other means of transportation to a suitable storage location.
- StorageCO₂ is pumped into underground geological formations, such as empty gas or oil fields, where it can be stored safely.
Advantages of CCS
The permanent storage of CO₂ prevents large quantities of climate-damaging gases from being released into the atmosphere. This is particularly important for industries that are difficult to decarbonize, such as the cement, steel and chemical sectors. Here, CCS can play a key role in reducing emissions where the use of renewable energies alone is not sufficient.
What is CCU - Carbon Capture and Utilization?
In contrast to CCS, CCU focuses on the recycling of CO₂. The captured carbon dioxide is not only captured but also used as a raw material in various industries. Examples of the application of CCU technologies include
- Chemical industryCO₂ is used to produce fuels, plastics or chemicals.
- Construction industryCO₂ can be incorporated into concrete, which also increases the strength of the material.
- Food industryCO₂ is used in the production of carbonated drinks or in the preservation of food.
Advantages of CCU
CCU supports the circular economy by converting CO₂ into products that can be used economically. This not only removes CO₂ from the air, but also creates new business opportunities for the industry. However, the CO₂ can later be released when these products are disposed of or incinerated.
CCS & CCU: differences and similarities
Both CCS and CCU aim to reduce the amount of CO₂ in the atmosphere, but they differ in the way they are used. Long-term nature of their effect. While CCS stores the CO₂ permanently in geological formations, CCU reuses it and often keeps it in the economic cycle. Depending on the end product, however, it can be released again.
However, both technologies are seen as the key to climate neutrality, as many industries are currently still unable to convert their processes and production to be CO₂-neutral. This applies in particular to sectors such as steel and cement production, which produce immense amounts of CO₂. CCS and CCU offer additional solutions here to minimize CO₂ emissions and thus achieve the goal of net zero emissions. According to experts such as the Intergovernmental Panel on Climate Change (IPCC), such technologies are indispensable when it comes to achieving global climate targets.
In Germany, the requirements for CCS and CCU are defined in the Federal Immission Control Act and the Carbon Dioxide Storage Act (KSpG), both of which are currently being amended accordingly. Both laws regulate, for example, the approval procedures for the construction of the necessary infrastructure, CO₂ pipelines and safety standards. All key points are summarized in the so-called Carbon Management Strategy.
Challenges & criticism
Despite the potential of CCS and CCU technologies, there are some points of criticism and challenges. Neither has yet been fully developed or tested in the long term. In Germany, there has so far only been one CO₂ storage pilot project in Brandenburg, and in Europe only Norway is one of the global pioneers. The Netherlands is currently preparing larger CO₂ storage facilities. Experts believe that the largest European storage capacities are located beneath the North Sea.
One of the main points of criticism is the high Cost and energy expenditure. The entire process - from the capture and transportation to the storage or reuse of CO₂ - is technically complex and energy-intensive. Critics argue that these technologies only make economic sense if either the CO₂ price is high enough or extensive subsidies are provided. This raises the question of whether the financial burden is sustainable in the long term, especially for countries or companies with limited resources.
Another problem is that CCU Not a permanent solution as the CO₂ is often only bound in products for a short time and can be released again later. There are also concerns about the long-term safety of CO₂ storage with CCS. There is a risk that the stored CO₂ will escape over time.
There are also concerns that CCS and CCU could delay the transition to renewable energies, as they could serve as a pretext for the continued unquestioning use of fossil fuels. The limited effectiveness of CCU is also criticized, as only a relatively small amount of CO₂ is permanently bound in products.
Conclusion: CCS & CCU as technologies for the future
Despite these criticisms, CCS and CCU technologies are important technologies for reducing CO₂ emissions and offer innovative solutions for industries that rely heavily on fossil fuels. They contribute to combating climate change and offer economic opportunities through the recycling of CO₂. However, both approaches face major challenges: High costs, technical complexity and uncertainties regarding long-term viability and safety are critical issues. There is also a risk that they could delay the switch to renewable energies. Nevertheless, CCS and CCU play a central role on the path to Decarbonization and to a more sustainable future.