Biogas plant for the production of biogas from biomass and method for operating the biogas plant

摘要

It is a biogas plant for the production of biogas from biomass with at least one fermenter, a method for safe shutdown of a fermenter and a method for safely starting a fermenter specified. For discharging spent biomass and for loading with fresh biomass, the individual fermenters must be shut down from time to time, d. H. Biogas production must be stopped. For safety reasons, it must be prevented that an explosive biogas / air mixture is produced during the unloading and loading of the individual fermenters. By flushing the fermenter during shutdown with carbon dioxide-containing exhaust gas on the one hand prevents an explosive biogas / air mixture and on the other hand, the biogas production is maintained as long as possible, d. H. the biogas / waste gas mixture of the fermenter to be switched off is fed on to the biogas consumer until the quality of this mixture falls below a predetermined level. Only when the methane concentration in the biogas outlet falls below an upper limit, the leading to the biogas consumer biogas line is separated from the biogas outlet. Thereafter, the only little methane-containing biogas / exhaust gas mixture is discharged through an exhaust chimney. This is done until the methane concentration has dropped to a lower limit, in which almost no more methane is contained in the biogas / exhaust gas mixture. Then the fermenter to be switched off ...