Renewable CO2 from food waste based biogas – a case story from Switzerland
Biogenic CO2 will be increasingly required in the future as substitute for fossil CO2 for chemical and food industries, as CO2 source for Carbon Capture and Storage (for negative emissions) and as renewable carbon source for carbon containing e-fuels or e-products. The purification of the CO2 rich off-gas from biomethane processing plants is a good option to provide renewable CO2.
This case story – developed in the frame of IEA Bioenergy Task 37 (biogas) – shows a biogas upgrading plant in Nesselnbach, Switzerland, where the offgas is treated to turn the CO2 into a commercial product.
It was proven that the CO2 upgrading process can be hooked onto existing biomethane plants. Liquefaction is of great importance for transportability. Increasing numbers of plants will improve the operational availability of the plants and likely reduce further the costs. However, at the moment the market for renewable CO2 does not allow economic operation without support schemes. If the further development of use or storage of biogenic CO2 is desired, framework conditions need to be set to support such a development.
Figure: Structure of the Biomethane processing with integrated CO2 liquefaction in the Nesselnbach plant.
