Method and device for operating a fermentation plant

摘要

A method for operating a fermentation plant with at least one digester that is supplied with a substrate. The substrate is percolated using a percolate from a percolate container and biogas that is generated via the percolation process in the digester or/and in the percolate container is drawn off. The drawn off biogas is treated in a biogas treatment device and the CO2-containing exhaust gas that is generated during the treatment is introduced into the digester using a purge line, for forcing out and drawing off the biogas that was generated in the digester. Alternatively CO2-containing biogas that was generated in an additional digester in a different fermentation process can be introduced into the digester for forcing out and drawing off the biogas that was generated in the digester. The CO2-containing purge gas is forced to pass through the substrate dislodging any trapped biogas.

主权项

1. A method for operating a fermentation plant having at least a first digester (1) to which a substrate to be digested (1a) is supplied and a least one additional digester, the method comprising:
percolating the substrate to be digested (1a) with a percolate (2a) from a percolate container (2), withdrawing biogas, containing methane and CO2, that is generated in the first digester (1) or/and in the percolate container (2), collecting CO2-containing biogas that has been generated during a fermentation process in said additional digester, wherein said biogas is collected in an earlier phase of fermentation in said additional digester relative to the phase of fermentation of the first digester (1) such that said biogas collected from said additional digester exhibits a higher CO2 content than the biogas present in the first digester (1), introducing the biogas collected from the additional digester into the first digester (1) as CO2-containing purge gas using a purge line (4), whereby the CO2-containing purge gas is introduced into a bottom region of the first digester (1) such that it passes through the substrate (1a), and dislodges any biogas that is present in the substrate (1a) into the substrate-free volume (1b) of the first digester (1) above the substrate (1a) for subsequent collection and removal.