CO2 recovery from biogas in Germany
Germany had 242 biomethane injection plants and 10.45 TWh of biomethane injection in 2024. Solveno Technologies recovers and liquefies the CO₂-rich off-gas from biogas upgrading, with project-specific integration for residual methane recovery.
Why CO₂ recovery is relevant to the German biomethane market
Germany already has a substantial biomethane infrastructure. According to the Bundesnetzagentur Monitoring Report 2025, 242 biomethane injection plants were operating in Germany in 2024, with 10.446 TWh of biomethane injected into the gas network. See the Bundesnetzagentur Monitoring Report 2025.
Biogas upgrading separates methane from CO₂ and other components to produce biomethane. This creates a CO₂-rich stream that can potentially be recovered instead of remaining a residual gas stream. Solveno Technologies operates downstream of the upgrading plant: we do not supply the biogas upgrading technology itself, but process the separated CO₂-rich gas for purification and liquefaction.
For more technical background, see our guide to biogas upgrading and CO₂ separation and our main page on CO₂ recovery from biogas upgrading.
CO₂-rich off-gas from German biogas upgrading plants
The German Fachagentur Nachwachsende Rohstoffe (FNR) describes several upgrading technologies used in Germany, including pressure swing adsorption, water scrubbing, physical and chemical absorption and membrane separation. These technologies separate CO₂ in different ways and therefore do not necessarily produce identical off-gas conditions. Read the FNR overview of biogas upgrading in Germany.
For downstream CO₂ recovery, the actual gas composition and operating conditions therefore have to be assessed for each German installation. Relevant parameters include CO₂ concentration, residual methane, oxygen, nitrogen, moisture, trace contaminants, flow, pressure and temperature.
Where the stream is suitable, it can be treated, purified, dried and liquefied. The required process configuration depends on the measured inlet gas and the specification required for the intended CO₂ outlet.
The German THG quota and biomethane
Germany uses a statutory greenhouse-gas reduction obligation for transport fuels, known as the THG-Quote. Under the current Bundes-Immissionsschutzgesetz, the required reduction is 12% in 2026 and increases to 17.5% in 2027. See §37a of the German Bundes-Immissionsschutzgesetz.
German law also defines the conditions under which biomethane qualifies as a biofuel for the THG quota. In particular, §37b of the Bundes-Immissionsschutzgesetz addresses biomethane supplied through the gas grid and the associated sustainability and traceability requirements. See §37b BImSchG.
Sustainability evidence for gaseous biomass used in the German market is handled through the governmental Nabisy system operated by the Bundesanstalt für Landwirtschaft und Ernährung (BLE). Gaseous biomass can only be counted towards relevant quota obligations when the applicable sustainability requirements are demonstrated. Read the BLE information on Nabisy.
CO₂ recovery should therefore not be treated as an automatic additional THG credit. For biomethane used as a transport fuel, any effect of CO₂ recovery on the certified greenhouse-gas value has to be assessed under the applicable calculation and certification methodology for the specific project.
German research on biogenic CO₂ from biomethane production
The potential value of CO₂ from biogas upgrading has been investigated specifically in Germany. From 2022 to 2025, the federally funded Bio-CO₂ research project led by Fraunhofer IEE examined the provision of CO₂ from biogas upgrading plants for material use.
The project investigated economically optimized CO₂ supply chains, their environmental performance and business models in which operators produce and market both biomethane and CO₂. It also aimed to provide guidance for plant operators and project developers. See the Fraunhofer IEE Bio-CO₂ project.
This German research confirms that CO₂ separated during biomethane production is being evaluated as a distinct product stream, but also that logistics, environmental performance and economics must be considered together.
CO₂ recovery as a retrofit to existing German biomethane plants
Germany's existing biomethane infrastructure makes retrofit particularly relevant. A CO₂ recovery project does not necessarily require replacement of the existing upgrading system. The starting point is the actual CO₂-rich stream already produced by that system.
For a retrofit assessment, Solveno Technologies evaluates the gas composition, minimum and maximum flow, available pressure, allowable backpressure, electrical connection, available space, storage requirements and control interfaces. Methane-containing streams during normal operation, start-up, shutdown and purging also have to be included in the integration concept.
What determines the business case in Germany?
The commercial viability of CO₂ recovery at a German biomethane plant depends on the complete project rather than the recoverable CO₂ volume alone.
- Available CO₂ stream: concentration and minimum, normal and maximum flow.
- Annual operating hours: these determine the annual quantity of liquid CO₂ over which investment and fixed costs are distributed.
- Electricity: both electricity consumption per tonne of saleable liquid CO₂ and the site-specific electricity price must be considered.
- Required CO₂ specification: the intended German outlet determines the required purification and quality control.
- Offtake and logistics: selling conditions, transport distance, collection frequency and storage requirements influence project economics.
- Residual methane: methane recovery can create additional value where a suitable return route exists in the current plant.
- German sustainability certification: when biomethane is used as a transport fuel, any effect on its certified greenhouse-gas performance must be evaluated under the applicable German sustainability and THG-quota framework.
The German Umweltbundesamt also stresses that CCU should be assessed on the basis of actual greenhouse-gas savings and the additional energy and resource requirements of the complete process. Read the Umweltbundesamt position on carbon capture and utilisation.
Modular CO₂ recovery systems for German biomethane projects
Solveno Technologies supplies modular CO₂ recovery and liquefaction systems for CO₂-rich off-gas from biogas upgrading. Standard configurations cover approximately 350 to 4,500 kg of CO₂ per hour. The final configuration is selected according to the measured gas composition, production profile, required liquid CO₂ specification and site integration.
Depending on project scope, the system can include gas treatment, compression, drying, cooling, liquefaction and distillation, together with liquid CO₂ storage, quality analysis and tanker-loading equipment.
Assess a German biomethane project
For an initial assessment, Solveno Technologies needs the plant location, upgrading technology, a recent off-gas analysis, minimum and maximum gas flows, pressure and temperature, annual operating hours and the required CO₂ specification. Electricity cost, available storage and the intended CO₂ outlet are also relevant when available.
These inputs allow the technical configuration, integration requirements and main business-case drivers for a German CO₂ recovery project to be assessed.
Official and independent sources for Germany
CO₂ Recovery from biogas upgrading
Recover and liquefy the CO₂-rich off-gas from biomethane upgrading into purified liquid CO₂, with methane recovery where relevant.
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