Main technologies for biogas upgrading are: absorption by solvents, adsorption, permeation by membrane.
ATProX’s activity focused on adsorption technology and on permeation technology, the first one is suitable to treat large flowrate, the second is suitable for even small project, starting from 50 Nm3/h of input biogas.
Membrane biogas upgrading technology is based on gas flow through hundreds of spaghetti-like thin fiber tubes with selective wall material.
The separation of carbon dioxide, water vapor, sulfur compounds, nitrogen, oxygen and siloxanes occur because of them diffusivity through the fiber wall material that is different compared to methane. While the unwanted compounds “escape” through the walls, purified methane travels to the other end of the tubes and is collected. This cycle can be repeated typically in two or three process steps to gain high enough quality of the end gas. Pretreatment options vary by application.
Advantages of membrane-based upgrading technology are the following:
- Suitable for even small project, starting from 50 Nm3/h of input biogas
- High gas quality
- Passive technology requires minimal supervision and maintenance
- Very small capital investment
- Membranes’ usable lifetime 5 to 8 years
- No moving parts
- No need for chemicals or water
- System scalable by adding or reducing the number of modules
- Easy, automated and remotely controlled process