Method and plant for the methanation of biomass

A method for the methanation of biomass and the energetic use of the biogas obtained in a plant featuring at least one fermenter (1) operating in batch processing mode, where in at least one fermenter the following sequence of steps is cyclically repeated:

• a) Filling the fermenter (1) with biomass through a loading hatch (2) open to the environment,
• b) airtight closing the loading hatch (2),
• c) feeding methane-rich biogas produced during the fermentation phase (II), at least temporarily, into a first gas storage unit (14),
• d) flushing the fermenter (1) with flushing air, and, at least temporarily, feeding the mixed gas with low methane content, which leaves the fermenter during the flushing phase (III), into a second gas storage unit (15),
• e) opening the loading hatch (2), and
• f) removing the digestate from the fermenter (1), where gas is removed from the second gas storage (15) unit and is mixed with biogas removed from the first gas storage (14), and the mixed gas produced in this way is subsequently used energetically.