How does the (B)plant work?
The principle of our biogas digesters is a plug flow system. We are feeding from one side and this ”plug” (the daily amount of substrate) is pushed from the inlet side during 30 days towards the outlet side and then exits the digester when it is fully digested.
This means the fresh material is not mixed with the already digested substrate and also the bacteria, which have different tasks, are not mixed. In general, this kind of system is more robust towards different amounts and kinds of substrate and also towards irregular feeding. Even if there is a scum-formation it can easily be broken by pushing the flexible material of the digester. This way even hard material can be mixed in again and the digester continues working also after a long idle time.
The greenhouse around the system helps to heat up the content to above 30 °C during the day, but at night the system will cool down and produce less/no gas. This system does not store gas inside the digester, but in an external storage bag.
The whole system is easily installed, emptied and moved.
Disadvantage: The pressure is not sufficient for lighting, unless the backpack is loaded with a very heavy weight of about 50 kg.