Inquiries & Help
Asco: First of all, please give us an insight into "CO2 Energie AG" and its range of products and services in the energy sector.
Lehmann: CO2 Energie AG is a joint venture between the two companies "Regionalwerke AG Baden" (RWB) and "Recycling Energie AG". The company was founded in 2021 with the aim of realising the CO₂ liquefaction plant at the site of the Nesselnbach biogas plant.
Asco: You describe the biogas plant installed by "CO2 Energie AG" in Nesselnbach/CH as a "pioneering project in Europe". How do biogas plants work in general?
Lehmann: In Nesselnbach, "Recycling Energie AG" operates a biogas plant. I.e., food waste is collected and processed. This is then fermented on site, producing raw biogas. Regionalwerke AG Baden (RWB) operates a biogas upgrading plant at the site, which processes the raw biogas. The end product, biomethane, can then be fed into the gas grid.
In addition, "CO2 Energie AG" has built a CO₂ liquefaction plant, i.e., the CO₂ that has so far escaped into the atmosphere and is separated during the biogas upgrading process is captured and liquefied there for use in the gas grid. various industrial applications. In technical jargon, this is referred to as "Bioenergy Car-bon Capture & Utilization (BECCU)".
Asco: What is special about this "pioneer plant" in Nesselnbach? Can you describe the recycling process?
Lehmann: The raw biogas, which is composed of 60 % methane and 40 % CO2, is processed and fed into the local gas grid. Before it is fed into the grid the raw biogas is pre-cleaned by activated carbon filters and then compressed to approx. 16-17 bar. Then the dry, compressed gas enters a membrane to split it into CH4 (methane) and CO₂ molecules. This end product must consist of at least 96 % methane gas. The CO₂ was previously discharged into the atmosphere.
With the new "carbon capture" process, the CO₂ is now collected, processed, cleaned, liquefied and then stored in tanks. With the new plant, around 90 % of the CO₂ produced can be made usable. That is up to 3,000 t per year. The special feature is that the liquid CO₂ is so pure after the process that it is "food grade". Our customer for CO₂ is the company "Messer Schweiz AG" in Lenzburg. The CO₂ is used for various applications, especially in the food industry. It is interesting to note that the end product CO₂ of food quality is created from the initial material of food waste.
CEO Regionalwerke AG Baden
Philippe Lehmann
(©Recycling Energie AG)
Asco: The plant is a joint project with "Hitachi Zosen Inova" and "ASCO Carbon Dioxide " from Romanshorn/CH. What does the cooperation look like?
Lehmann: CO₂ Energie AG ordered the plant as a complete system from Hitachi Zosen Inova. ASCO was chosen by Hitachi Zosen Inova for the CO2 liquefaction. The Nesselnbach project is the first plant of its kind in Switzerland and a very good prime example of how CO₂ can be sensibly captured and recycled.
Asco: The need to reduce CO2 emissions worldwide is great. Is the Nesselnbach project a "model case" for the energy industry in particular or do you see further approaches?
Lehmann: There are various promising approaches. Carbon capture and storage (CCS) is particularly interesting. There are various applications for permanently "storing" the recovered CO2, for example in recycled concrete or in long-term storage facilities such as empty natural gas or oil fields.
Asco: Are further biogas plants with Carbon Capture planned at Regionalwerke Baden?
Lehmann: Absolutely! We are always looking for more CO₂ sources so that we can plan, build and operate more plants. It is essential for us to duplicate the know-how we have built up in this area.
Asco: How has the industry reacted to your project? For the sake of "our" carbon footprint, numerous imitators would be desirable.
Lehmann: I believe that this pilot project is an important door opener for further projects. The entire industry, especially the biogas industry, sees that it is possible to realise such a plant and also to operate it economically.
In any case, the industry has reacted with great interest. We receive many enquiries for visits to the plant. It is really crucial that such a plant is located in Switzerland and that people can find out how it works on site. We have experienced ourselves how difficult it is to plan without an existing plant through which one can benefit from a certain transfer of knowledge.
Asco: If there are no CO2 off-takers in future biogas projects, "Carbon Capture & Storage" (CCS) is an idea that you have already gone through?
Lehmann: The CCS idea, i.e., "Carbon Capture & Storage", is certainly interesting for us. With the know-how we have gained, we want to operate more plants in the future. We also have other biogas processing plants where the CO₂ is still released into the atmosphere.
At some point, CO₂ consumption or the reduction of CO₂ in Switzerland will stagnate. Then we will certainly have to think about how to deal with the surplus CO₂. That is why we are definitely examining various scenarios here.
Asco: Thank you for the interview Mr. Lehmann!
About Regionalwerke AG Baden
Regionalwerke AG Baden supplies the city of Baden and the surrounding region with energy and water. In addition to a secure and reliable energy supply, RWB offers its customers a wide range of services in the field of energy solutions, both outside and outside the supply area. RWB supports its customers personally and with full energy.
About Recycling Energie AG
Recycling Energie AG operates the largest plant in Switzerland for the production of raw gas from food waste. It produces around 1 800 m3 of biogas per hour. Two thirds of this is converted into green electricity. This supplies around 5 000 households. The other third is processed by RWB and fed into its natural gas grid as biogas. This gas can be used to heat about 2 500 households. In addition, Recycling Energie AG produces about three million litres of biofuel every year.
(©Recycling Energie AG)