My small biogas plant produces around 200 liters of methane each day using just a few kitchen scraps and some green waste.
It is made from cheap plumbing parts, and I can generate my own energy continuously and safely without much effort.
In the fermentation tank, the daily substrate supply is broken down by bacteria mainly into methane (CH₄), carbon dioxide (CO₂) and a fertile fermentation residue.
Here is the link to a detailed YouTube video showing how to build your own mini biogas plant: YouTube biogas video