Abstract: The invention relates to an apparatus for the conversion into biogas of fermentation stillage arising as a waste product of ethanol production. This apparatus comprises a separation unit for the separation of the fermentation stillage into a thin fraction and a thick fraction, at least one biogas reactor for fermenting the thin fraction and/or the thick fraction, and a storage tank. According to a first aspect of the present invention, two biogas reactors are provided, to separate the thin fraction and the thick fraction independently of one another. According to a second aspect of the present invention, a nitrogen sink is provided downstream of the storage tank to provide, from the reactor effluent, process water with low or no nitrogen content which may then be fed to the reactor and/or the bioethanol plant. According to a third aspect the invention is characterized by a combination of a single-stage separation unit and a heavy-duty biogas reactor with a pore-free flow path.

Abstract: The process according to the invention for the microbial production of a specific product and methane comprises the following steps: a) the production in a bioreactor (2, 10) of a specific product from a specific substrate using a specific organism, the producer, wherein during the production of this product metabolites such as e.g. low-molecular alcohols, aldehydes and acids, hydrogen and CO2, which may inhibit the production of the product, are obtained; and b) the production of methane by means of a methanogen, wherein in the production of the methane at least one metabolite is decomposed and by this means removed from the bioreactor (2, 10) and its energy is made usable.

Abstract: An agitator for a fermenter, a fermenter and method of operating a fermenter are provided. The agitator has an agitator shaft which stands roughly vertically in the fermenter. Because of this, the substrate in the fermenter is circulated in horizontal planes. This allows the formation of several layered decomposition zones. In addition, the agitator is preferably designed so that it may be removed upwards from the fermenter during continuing operation. This means that it is not necessary to empty the fermenter for maintenance work on the agitator.

Abstract: The invention relates to a trace element solution for the supplementing of nutrients for an anaerobic fermentation, in particular a biogas process, comprising at least one trace element and at least two complexing agents. Complexing agents are used which (1) are able to transport the trace elements in complexed form across the cell membrane and which (2) release the trace elements in the cell. Where applicable, the complexing agents are biologically decomposable.

Abstract: The process according to the invention for the microbial production of a specific product and methane comprises the following steps: a) the production in a bioreactor (2, 10) of a specific product from a specific substrate using a specific organism, the producer, wherein during the production of this product metabolites such as e.g. low-molecular alcohols, aldehydes and acids, hydrogen and CO2, which may inhibit the production of the product, are obtained; and b) the production of methane by means of a methanogen, wherein in the production of the methane at least one metabolite is decomposed and by this means removed from the bioreactor (2, 10) and its energy is made usable.

Abstract: The invention relates to an apparatus for the conversion into biogas of fermentation stillage arising as a waste product of ethanol production. This apparatus comprises a separation unit for the separation of the fermentation stillage into a thin fraction and a thick fraction, at least one biogas reactor for fermenting the thin fraction and/or the thick fraction, and a storage tank. According to a first aspect of the present invention, two biogas reactors are provided, to separate the thin fraction and the thick fraction independently of one another. According to a second aspect of the present invention, a nitrogen sink is provided downstream of the storage tank to provide, from the reactor effluent, process water with low or no nitrogen content which may then be fed to the reactor and/or the bioethanol plant. According to a third aspect the invention is characterised by a combination of a single-stage separation unit and a heavy-duty biogas reactor with a pore-free flow path.