Currently, green gas is produced through the anaerobic digestion of organic materials. This can be done in dedicated installations where organic material such as manure and corn is fed into a digester. In addition biogas can be produced from sewage sludge or from the organic material present in landfills. Biogas that is produced in this process has a different composition in comparison to natural gas found around the world. The main components of biogas are methane (around 60%) and CO2 (around 40%). In order to inject it into natural gas grids, the methane content needs to be raised and contaminants such as H2S, NH3, siloxane and excess water need to be removed. The methane content is raised by removing CO2. If biogas is upgraded to the extent that it has the same properties as natural gas, this gas is called green gas.
In the future, green gas will also be produced through the gasification of biomass with a high lignin content (which is anaerobically indigestible). Gas produced through this process is called syngas. In this process biomass is exposed to extreme heat (around 1000°C) at high pressure to partially combust biomass. Gasification is not yet implemented on a large commercial scale, but it is expected to grow in importance in the (near) future. 

Green gas can develop into an important component of the energy transition. In the EU, natural gas makes up almost 25% of the primary energy mix. In order to move towards a low carbon economy, a large part of our energy mix needs to be decarbonized. Because natural gas makes up such a large part of the worldwide primary energy mix, the production of green gas could help to achieve this goal. In 2009 8.3Mtoe biogas production was realized in the EU. So far, Germany is by far the largest producer of biogas in the EU, providing around 50% of the total EU production .

In the Netherlands, according to Koppejan (2009) with domestically available biomass, in 2020 a maximum of some 1.25 BCM biogas (natural gas equivalent) is achievable. With the import of biomass this amount could be considerably increased.

Besides providing general information about among others biogas technology, EDIaal will also provide more fundamental research papers and keep you updated on current developments in this field