Green gas (or 'biomethane' or 'RNG') is biogas that "cleaned" in order to obtain the same quality as natural gas. Biogas consists of approximately 55% methane (CH4) and 45% carbon dioxide (CO2). In addition, the biogas contains H2S and often also volatile organic hydrocarbons (VOCs), such as siloxanes and terpenes. The biogas is also saturated with moisture. Natural gas consists of approximately 90% CH4 and 10% N2, is dry and does not contain NH3 and H2S. Natural gas also contains an odorant (THT), which gives the gas its characteristic odor.
The operation of a biogas upgrading installation is therefore based on the following principles:
- Drying the gas
- Removal of NH3, H2S and volatile organic hydrocarbons, often by means of activated carbon
- Removal of CO2
- Quality control of the green gas with a gatekeeper
- Addition of fragrance THT (odorant with characteristic odor for natural gas)
When upgrading, all contaminants are filtered from the biogas and the biogas is restored. The CO2 is also largely removed from the biogas, leaving green gas that is qualitatively exactly equal to natural gas. The green gas is then inspected by a gatekeeper and fed into the natural gas network.
Biogas Plus has many years of experience with all aspects of green gas:
- Different technologies for upgrading the biogas
- Quality control and feed into the natural gas network
- Use as a transport fuel
- Production of green CO2 from the residual gas from the reprocessing
- Certification (Vertogas, NTA8080)
Biogas Plus can engineer, supply and install green gas installations. This extends from the connection to the digester up to and including the connection to the natural gas network. This can be integrated in a turn-key project with the biogas production, but also separately with an existing digester.