Multilevel application system for a plug flow fermenter

Abstract

What is disclosed is a biogas plant having a plug flow fermenter with a first discharge opening and a second discharge opening, a pump apparatus for withdrawing fermenter contents through the first discharge opening and the second discharge opening and releasing the fermenter contents withdrawn into a discharge conduit; and a control device configured to control the withdrawal of fermenter contents through the first discharge opening and the second discharge opening into the pump apparatus and hence to adjust characteristics of the fermenter contents withdrawn in the discharge conduit. A method of operating a biogas plant and a corresponding computer program product bring about control of withdrawal of fermenter contents through the first discharge opening and the second discharge opening, in order thus to adjust characteristics of the fermenter contents withdrawn in a discharge conduit.

Description

[0001] Multi-level discharge system for a plug-flow fermenter

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to the field of biogas plants, in particular biogas plants with a plug flow fermenter.

[0004] BACKGROUND

[0005] EP 1 987 130 B1 discloses a horizontal plug-flow fermenter for biogas production with several reaction volume cells (stirred cells) connected in series, each equipped with slow-running bar agitators on axes perpendicular to the flow direction of the fermenter. If significant amounts of inert bottom sediment develop over a long period of time, they can be moved to the area of ​​the bottom-level discharge nozzle and removed from the reactor by rotating the last agitator counterclockwise.

[0006] SUMMARY

[0007] Known methods for optimizing the operation of a biogas plant with a plug-flow fermenter (hereinafter also referred to as "fermenter") typically start in the fermenter itself and attempt to optimize desired conditions by influencing the fermenter contents. In plug-flow fermenters, removing impurities from the fermenter can be problematic, especially during the commissioning phase, during abrupt seasonal changes, or when the fermenter is not operated optimally. For example, a discharge line can become blocked.

[0008] Furthermore, reliable fermentation of input materials with a high proportion of impurities is desirable for plug-flow fermenters. Such input materials with a high proportion of impurities include, for example, biowaste or the organic fraction of general waste. However, in the fermenter discharge area, where the fermenter contents become more liquid due to the fermentation process, the impurities present increasingly cause problems, such as the aforementioned blockage of the discharge line.

[0009] In view of the situation described above, there is a need for a technique that allows reliable operation of a plug flow fermenter while substantially avoiding one or more of the problems identified above.

[0010] This need is addressed by the independent claims. Advantageous embodiments are specified in the dependent claims.

[0011] According to a first aspect of the subject matter disclosed herein, a biogas plant is provided.

[0012] According to an embodiment of the first aspect, a biogas plant is provided, comprising: a plug-flow fermenter with at least two discharge openings, wherein the at least two discharge openings comprise a first discharge opening and a second discharge opening; a pumping device for removing fermenter contents through the at least two discharge openings and discharging the removed fermenter contents into a discharge line; a control device configured to control a removal of fermenter contents through the at least two discharge openings into the pumping device and thereby adjust a quality of the removed fermenter contents in the discharge line.

[0013] According to a second aspect of the subject matter disclosed herein, a method is provided.

[0014] According to an embodiment of the second aspect, a method is provided for operating a biogas plant with a plug flow fermenter having at least two discharge openings, wherein the at least two discharge openings comprise a first discharge opening and a second discharge opening, the method comprising: controlling a removal of fermenter content through the at least two discharge openings in order to thereby adjust a quality of the removed fermenter content in a discharge line.

[0015] According to a third aspect of the subject matter disclosed herein, a computer program product is provided.

[0016] According to an embodiment of the third aspect, a computer program product is provided, the computer program product comprising a program element configured to control a method according to the second aspect or at least one embodiment thereof when executed on a processor device. DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0017] According to one embodiment, a biogas plant according to the first aspect of the subject matter disclosed herein comprises a plug-flow fermenter. According to one embodiment, the plug-flow fermenter has at least two discharge openings. The at least two discharge openings comprise a first discharge opening and a second discharge opening. According to a further embodiment, the biogas plant has a pumping device for removing fermenter contents through the at least two discharge openings (in particular through the first discharge opening and through the second discharge opening) and discharging the removed fermenter contents into a discharge line.According to a further embodiment, the biogas plant comprises a control device which is configured to control a removal of fermenter contents through the at least two discharge openings (in particular through the first discharge opening and the second discharge opening) into the pumping device and thereby to adjust a quality of the removed fermenter contents in the discharge line.

[0018] According to one embodiment, a method according to the second aspect comprises controlling the removal of fermenter contents through at least two discharge openings (in particular through the first discharge opening and through the second discharge opening) in order to thereby adjust the quality of the removed fermenter contents in the discharge line. According to one embodiment, a computer program product according to the third aspect effects the execution (control) of such a method.

[0019] At least some of the aspects and embodiments of the subject matter disclosed herein are based on the idea that an inhomogeneous fermenter content present in the fermenter can be achieved by removing fermenter content through at least two discharge openings and discharging the removed fermenter content into a discharge line in the discharge line, regardless of the homogeneity of the fermenter content in the fermenter. According to one embodiment, the discharge line is thus a common discharge line through which the fermenter content removed through the first discharge opening and the fermenter content removed through the second discharge opening are discharged.The flexible combination of material removal from the fermenter ensures, on the one hand, that impurities cannot accumulate in the fermenter (or only to a reduced extent) and, on the other hand, that the impurity content, in combination with a pump and piping used according to one embodiment, does not lead to blockages.

[0020] Impurities within the meaning of this disclosure are substances that do not contribute to fermentation. Impurities can, for example, be substances that are not subject to any or only a minor fermentation during the typical residence time in the fermenter. Examples of impurities include sand, stones, metal particles, stone fruit kernels, etc.

[0021] According to one embodiment, a plug-flow fermenter is a fermenter designed to ferment a fermenter content with a dry matter content between 15 and 45 percent (e.g., 25 to 40 percent at the inlet and 15 to 30 percent at the outlet). For this reason, fermentation in a plug-flow fermenter is also referred to as dry fermentation.

[0022] According to one embodiment of the subject matter disclosed herein, a discharge opening of a plug-flow fermenter is an opening provided for removing fermenter contents from the plug-flow fermenter. According to one embodiment, a quality of the removed fermenter contents in the discharge line is, for example, a homogeneity of the removed fermenter contents in the discharge line and / or a concentration of impurities in the removed fermenter contents in the discharge line.

[0023] According to one embodiment, the at least two discharge openings (in particular the first discharge opening and the second discharge opening) are arranged at a discharge end of the plug-flow fermenter. For example, according to one embodiment, the first discharge opening and / or the second discharge opening are arranged on an end face of the plug-flow fermenter.

[0024] For example, according to one embodiment, the first discharge opening and the second discharge opening are arranged such that a first type of fermenter content can be removed through the first discharge opening and a second type of fermenter content can be removed through the second discharge opening, wherein the first type of fermenter content has a higher impurity content than the second type of fermenter content.

[0025] According to a further embodiment, the first discharge opening is arranged below the second discharge opening. The term "below" (and analogously also the term "above") refers to arrangements at different heights in a direction parallel to the Earth's gravitational field. In this sense, an arrangement of the first discharge opening below the second discharge opening means that the first discharge opening is at a shorter distance from the Earth's surface than the second discharge opening.

[0026] According to one embodiment, the biogas plant has a longitudinal

[0027] Agitator in the plug flow fermenter. In a

[0028] In a plug-flow fermenter, the fermentation substrate moves in a transport direction from the inlet end of the fermenter to the outlet end. With a longitudinal agitator, the agitator axis is arranged along the transport direction (parallel to the transport direction). By controlling the removal of the fermenter contents through the first discharge opening and the second discharge opening into the pumping device, the quality of the removed fermenter contents in the discharge line can be adjusted, especially with a longitudinal agitator.

[0029] According to one embodiment, the control device is configured to effect a removal of fermenter contents through the first discharge opening over a first period of time and to effect a removal of fermenter contents through the second discharge opening over a second period of time, wherein the first period of time and the second period of time are different. For example, according to one embodiment, the first period of time and the second period of time can follow one another in time, e.g. immediately one after the other or with a time interval. According to a further embodiment, the first period of time and the second period of time can overlap in time. According to one embodiment, for this purpose, for example, a configuration and the control of the pumping device can be adapted accordingly.

[0030] According to one embodiment, the pumping device comprises a piston pump. For example, according to one embodiment, the removal of fermenter contents through the first discharge opening and the removal of fermenter contents through the second discharge opening are carried out by a single piston pump.

[0031] According to a further embodiment, the pumping device comprises two or more piston pumps. Furthermore, according to one embodiment, the pumping device comprises a valve arrangement by which a removal of fermenter contents by the at least one piston pump through the first discharge opening and / or through the second discharge opening can be controlled. According to one embodiment, the valve arrangement of the pumping device comprises at least one valve, for example, one valve for each discharge opening (n valves for n discharge openings, where n is a natural number greater than or equal to 2). According to one embodiment, two or more valves can be implemented as a combined valve.

[0032] According to one embodiment, the biogas plant has an operating element with which a ratio of a fermenter content removed through the first discharge line to a fermenter content removed through the second discharge opening can be adjusted. According to one embodiment, the ratio is volume-related, i.e., according to one embodiment, a ratio of a volume of fermenter content removed through the first discharge line to a volume of fermenter content removed through the second discharge opening can be adjusted. According to another embodiment, the ratio can be weight-related.

[0033] According to one embodiment, the biogas plant further comprises a sensor device for determining the quality of the removed fermenter contents in the discharge line. The sensor device can, for example, comprise a pressure sensor for determining a pressure in the discharge line, for example a pressure sensor of the piston pump. Since the pressure in the discharge line depends on the quality of the fermenter contents in the discharge line, this pressure is a measure of the quality of the fermenter contents in the discharge line. According to one embodiment, the control device is configured to control the removal of fermenter contents through the first discharge opening and through the second discharge opening.

[0034] Controlling the removal of fermenter contents through the first discharge opening and through the second discharge opening can, for example, be control in the sense of adjustment. For example, according to one embodiment, the control device can be configured so that the volume removed through the first discharge opening can be adjusted relative to the volume removed through the second discharge opening. According to a further embodiment, absolute volumes can be adjusted. When controlling in the sense of adjustment, the biogas plant can be configured (for example, a display element can be provided) to display to an operator the condition of the removed fermenter contents in the discharge line as determined by the sensor device, for example by displaying a parameter that represents the condition. Such a parameter can, for example, be a pressure in the discharge line, e.g.a counterpressure built up by the discharge line (ie the fermenter contents therein), which acts on an outlet of the pumping device to which the discharge line is connected.

[0035] According to a further embodiment, controlling the removal of fermenter contents through the first discharge opening and through the second discharge opening can be a control in the sense of a regulation. Control in the sense of a regulation can, for example, be an automatic adjustment (e.g., of the ratio) based on an output of the sensor device, e.g., an automatic adjustment based on a controlled variable, e.g., the aforementioned parameter. According to one embodiment, the control device is configured to control the removal of fermenter contents through the first discharge opening and the second discharge opening depending on the nature of the removed fermenter contents in the discharge line, as determined by the sensor device.

[0036] If, for example, a fermenter content can be removed through the first discharge opening which has an increased impurity content compared to a fermenter content which can be removed through the second discharge opening, according to one embodiment the control device can be set up to (automatically) reduce the removal of fermenter content through the first discharge opening relative to the removal of fermenter content through the second discharge opening if the impurity content in the discharge line is too high.

[0037] The removal of fermenter contents through the first discharge opening and the second discharge opening is controlled by appropriately controlling the volumes of fermenter contents removed from the fermenter through the first discharge opening and the second discharge opening. The volumes can be controlled, for example, by a corresponding number of piston strokes of a piston pump or by a corresponding portion of a single piston stroke.

[0038] For example, if the fermenter contents are removed through the first discharge opening and the second discharge opening by a single piston pump, the fermenter contents can be removed through the first discharge opening in a first partial stroke of the piston pump and the fermenter contents can be removed through the second discharge opening in a second partial stroke of the piston pump. Of course, the order of the partial strokes in which the fermenter contents are removed through the first discharge opening or through the second discharge opening can be chosen arbitrarily. In other words, the method can also be operated in reverse, i.e. in a first partial stroke of the piston pump, the fermenter contents are removed through the second discharge opening and in a second partial stroke of the piston pump, the fermenter contents are removed through the first discharge opening.The decisive factor for adjusting the quality of the fermenter contents removed in the discharge line is the corresponding proportion of the fermenter contents removed through the first discharge opening relative to the proportion of the fermenter contents removed through the second discharge opening. Removing fermenter contents with corresponding partial strokes (e.g., n partial strokes with n discharge openings) has the advantage that fermenter contents removed through various discharge openings are already mixed in the piston pump, thus achieving a high degree of homogeneity of the fermenter contents in the discharge line.

[0039] Controlling a method disclosed herein can be performed, for example, by a suitable computer program product. For example, according to one embodiment, the control device can comprise a processor device. According to one embodiment, a program element of the computer program product, when executed on the processor device, controls a method according to embodiments of the subject matter disclosed herein.

[0040] According to embodiments of the first aspect, the biogas plant is configured to provide the functionality of one or more of the embodiments disclosed herein and / or to provide the functionality required for one or more of the embodiments disclosed herein, in particular the embodiments of the first aspect, the second aspect, and / or the third aspect. According to embodiments of the second aspect, the method is configured to provide the functionality of one or more of the embodiments disclosed herein and / or to provide the functionality required for one or more of the embodiments disclosed herein, in particular the embodiments of the first aspect, the second aspect, and / or the third aspect.

[0041] According to embodiments of the third aspect, the computer program product is configured to provide the functionality of one or more of the embodiments disclosed herein and / or to provide the functionality required for one or more of the embodiments disclosed herein, in particular the embodiments of the first aspect, the second aspect and / or the third aspect.

[0042] According to one embodiment, the program element is a non-transient program element. As used herein, reference to a computer program product is considered equivalent to a reference to a computer program comprising a program element and / or a computer-readable medium comprising a program element.

[0043] According to one embodiment, a program element comprises instructions for controlling a processor device (having one or more microprocessors, e.g., a computer system) to effect and / or coordinate the execution of a method described herein.

[0044] The (non-transient) program element may be implemented as computer-readable instruction code using any suitable programming language, such as JAVA, C#, or those typically used in PLC controllers (SCL, AWL, etc.), and may be stored on a computer-readable medium (removable disk, volatile or non-volatile memory, embedded memory / processor, firmware, etc.). According to one embodiment, the instruction code is executable for programming a computer or any other programmable processor device to perform the intended functions. The computer program may be available on a network, such as the World Wide Web, from which it may be downloaded, for example.

[0045] The subject matter disclosed herein can be implemented by means of a computer program product (more precisely, by means of the program element contained therein) or software. However, the subject matter disclosed herein can also be implemented by one or more specific electronic circuits or hardware. Furthermore, the subject matter disclosed herein can also be implemented in hybrid form, i.e., in a combination of software modules and hardware modules.

[0046] Exemplary embodiments of the subject matter disclosed herein are described below, with reference, for example, to a biogas plant, a method, and / or a computer program product. It should be emphasized that any combination of features of different aspects, embodiments, and examples is naturally possible. In particular, some embodiments are described with reference to a method, while other embodiments are described with reference to a biogas plant. Yet other embodiments are described with reference to a computer program product, while other embodiments are described with reference to a control device for interacting with elements of the biogas plant.However, those skilled in the art will appreciate from the foregoing and following descriptions, claims, and drawings that, unless otherwise stated, features of various aspects, embodiments, and examples may be combined, and such combinations of features are to be considered as disclosed by this application. For example, even a feature relating to a method may be combined with a feature relating to a device, and vice versa.

[0047] Further advantages and features of the present disclosure will become apparent from the following exemplary description of currently preferred embodiments, to which the claimed invention is not limited, however. The individual figures of the drawings in this document are to be considered merely schematic and not to scale.

[0048] BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Fig. 1 shows a biogas plant according to embodiments of the subject matters disclosed herein.

[0050] Fig. 2 shows a partial view of the pumping device from Fig. 1.

[0051] Fig. 3 shows another pumping device according to embodiments of the subject matter disclosed herein.

[0052] Fig. 4 shows a part of another biogas plant according to embodiments of the subject matter disclosed herein.

[0053] DETAILED DESCRIPTION

[0054] It is noted that in different figures, similar or identical elements or components are provided with the same reference numerals, or with reference numerals that differ only in the first digit. Such features or components that are the same or at least functionally equivalent to the corresponding features or components in another figure are described in detail only at their first appearance in the following text, and the description is not repeated for subsequent appearances of these features and components (or the corresponding reference numerals).

[0055] Fig. 1 shows a biogas plant 100 according to embodiments of the subject matter disclosed herein. According to one embodiment, the biogas plant 100 comprises a plug-flow fermenter 101. The plug-flow fermenter 101 has, according to one embodiment, a first discharge opening 102 and a second discharge opening 104. According to one embodiment, the plug-flow fermenter 101 is filled with a fermenter content 103, for example, up to a nominal height 105, for example, as shown in Fig. 1.

[0056] Furthermore, according to one embodiment, the biogas plant 100 comprises a pumping device 106, with which the fermenter contents 103 in the plug-flow fermenter 101 can be removed through the first discharge opening 102 and / or through the second discharge opening 104. According to one embodiment, the pumping device 106 is configured to discharge the fermenter contents, which are removed through the first discharge opening 102 or through the second discharge opening 104, into a discharge line 108, for example, as shown in Fig. 1.

[0057] According to one embodiment, the biogas plant comprises a control device 110 configured to control the removal of fermenter contents 103 through the first discharge opening 102 and the second discharge opening 104 into the pumping device 106 and thereby adjust the quality of the removed fermenter contents in the discharge line 108. According to another embodiment, the pumping device 106 is directly connected to the discharge openings 102, 104 and the discharge line 108, for example, via suitable piping (e.g., piping 150, for example, as shown in Fig. 1). According to one embodiment, a "direct connection" in this context means that, apart from the volume of the piping and the pumping device 106 (e.g., a piston pump) itself, no separate reservoir, for example, no separate collecting container for collecting fermenter contents, is provided.According to a further embodiment, the discharge line 108 connects the pumping device 106 directly to a drainage device 109, for example, as shown in Fig. 1. Other embodiments do not have a drainage device 109. For example, the discharge line 108 can open into an open area of ​​the biogas plant 100 (not shown in Fig. 1).

[0058] According to one embodiment, the control device 110 has a processor device 112 and a memory device 114 in which a program element according to embodiments of the subject matter disclosed herein is stored. According to one embodiment, the program element, when executed on the processor device 112, effects a functionality of the control device 110 according to embodiments of the subject matter disclosed herein. According to one embodiment, the control device 110 is control-connected to the pumping device 106, for example, as shown in Fig. 1 at 116. According to one embodiment, the connection 116 between the control device 110 and the pumping device 106 is a bidirectional connection, for example, a bidirectional signal transmission connection.

[0059] According to one embodiment, the plug-flow fermenter comprises an agitator 118. According to one embodiment, the agitator 118 is a longitudinal agitator, for example, as shown in Fig. 1. According to one embodiment, an agitator axis 120 of the agitator 118 extends in a longitudinal direction 122 of the plug-flow fermenter 101. In other words, the agitator 118 is a longitudinal agitator according to one embodiment, for example, as shown in Fig. 1. According to another embodiment, the agitator comprises an agitator shaft 119 and a plurality of agitator paddles attached to the agitator shaft, some of which are shown at 121 in Fig. 1.

[0060] According to one embodiment, the plug-flow fermenter 101 has an inlet end 123 and a outlet end 124. According to one embodiment, the agitator axis 120 extends in a direction from the inlet end 123 to the outlet end 124. According to one embodiment, fresh fermentation substrate is introduced into the plug-flow fermenter 101 at the inlet end 123. According to one embodiment, the first outlet opening 102 and the second outlet opening 104 are arranged at the outlet end 124. According to one embodiment, the outlet end 124 comprises an end face 126 and an adjacent wall region 128 of the plug-flow fermenter 101. According to one embodiment, both the first outlet opening 102 and the second outlet opening 104 are arranged at the end face 126 of the outlet end 124, for example, as shown in Fig. 1.According to one embodiment, the first discharge opening 102 is arranged below the second discharge opening 104, for example as shown in Fig. 1.

[0061] According to one embodiment, the biogas plant comprises a sensor device with which the quality of the fermenter contents in the discharge line 108 can be determined. According to one embodiment, the sensor device is a pressure sensor 130. For example, according to one embodiment, the pressure sensor 130 can be a pressure sensor of the piston pump, with which a resistance (e.g., a backpressure) in the discharge line 108 against which the piston pump must work can be determined. Fig. 2 shows a partial representation of the pump device 106 from Fig. 1.

[0062] According to one embodiment, the pumping device 106 comprises a piston pump 131, for example as shown in Fig. 2. According to one embodiment, the piston pump 131 comprises a piston 132, which is movable via a rod 133 within a cylinder 134 between a bottom dead center 136 and a top dead center 138. The distance between the bottom dead center 136 and the top dead center 138 corresponds to the piston stroke 140. When the piston 132 moves from the top dead center 138 to the bottom dead center 136, fermenter contents 103 can be sucked in through the first discharge opening 102 and / or through the second discharge opening 104. For example, according to one embodiment, the pumping device 106 is controlled in such a way that during a first partial stroke 142, fermenter contents 103 (not shown in Fig. 2) are discharged through the first discharge opening 102 (in Fig.2 not shown) and during a second partial stroke 144 fermenter content 103 is sucked into the piston pump through the second discharge opening 104 (not shown in Fig. 2), for example as shown in Fig. 2.

[0063] According to a further embodiment, a full piston stroke 140 is always taken into the piston pump either through the first discharge opening 102 or through the second discharge opening 104. A ratio of fermenter contents taken in through the first discharge opening 102 relative to the fermenter contents taken in through the second discharge opening 104 can in this case be adjusted by a corresponding number of piston strokes (e.g., two piston strokes through the first discharge opening 102 and one piston stroke through the second discharge opening 104 for a ratio of two to one). Fig. 3 shows a further pumping device 106 according to embodiments of the subject matter disclosed herein.

[0064] According to one embodiment, the pumping device 106 comprises a piston pump 131, for example a piston pump 131 as described with reference to Fig. 2. According to a further embodiment, the pumping device 106 comprises a valve arrangement 146, with which an inlet 148 of the piston pump 131 can be fluidly connected to at least one of the first discharge opening 102 and the second discharge opening 104, for example via pipes 150, for example as shown in Fig. 3.

[0065] According to one embodiment, the valve arrangement 146 is a separate valve arrangement. According to a further embodiment, the valve arrangement 146 can be integrated into the piston pump 131. For example, according to a further embodiment, the piston pump can have a first inlet and a second inlet (not shown in Fig. 3), wherein the first discharge opening 102 is connected to the first inlet and the second discharge opening 104 is connected to the second inlet. In this case, it can be provided that the first inlet and the second inlet can each be selectively closed and opened by the valve arrangement in order to thereby determine through which discharge opening 102, 104 fermenter contents are sucked in by the piston pump.

[0066] Fig. 4 shows a part of another biogas plant 200 according to embodiments of the subject matter disclosed herein.

[0067] According to one embodiment, the plug-flow fermenter 101 has at least one further discharge opening 152, in addition to the first discharge opening 102 and the second discharge opening 104, for example, as shown in Fig. 4. In this sense, by removing fermenter contents removed through the first discharge opening 102 and the second discharge opening 104, the quality of the removed fermenter contents in the discharge line 108 is adjusted, even if the removed fermenter contents in the discharge line 108 also originate, among other things, from further discharge openings in 152. In other words, reference to the first discharge opening 102 and the second discharge opening 104 does not exclude a further discharge opening 152.Likewise, a reference to adjusting a quality of the removed fermenter content in the discharge line 108 by removing fermenter content through the first discharge opening 102 and the second discharge opening 104 does not exclude a further adjustment of the quality of the removed fermenter content in the discharge line 108 by removing fermenter content through a further discharge opening 152.

[0068] According to a further embodiment, the pumping device 106 is fluidly connected to each of the discharge openings 102, 104, 152, for example via pipes 150, for example as shown in Fig. 4.

[0069] The pumping device 106 and the control device 110 (including their components), the discharge line 108, and the respective connections 116, 150 can collectively also be referred to as a discharge system.

[0070] As can be seen from the present description, embodiments of the subject matter disclosed herein allow for monitoring and / or regulating an impurity concentration in the discharge line 108 by withdrawing fermenter contents from different heights within the fermenter cross-section. Accordingly, a uniform concentration of impurities for the further conveying discharge line system can be established and controlled, in particular by means of the ratio of fermenter contents removed via a higher discharge opening (lower impurity concentration) to fermenter contents removed via a lower discharge opening (higher impurity concentration).

[0071] When using a piston pump, the mixing of fermenter content removed via the first discharge opening and fermenter content removed via the second discharge opening can be realized with partial amounts within one piston stroke of the piston pump or with alternating full strokes (for example as described with reference to Fig. 2).

[0072] According to embodiments of the subject matter disclosed herein, an inhomogeneous fermenter content (for example due to non-optimal operation of the fermenter or due to difficult material characteristics of the fermentation substrate introduced into the fermenter) can be optimally homogenized with a controlled withdrawal of fermenter content from different heights, for example during a single suction process of the piston pump.

[0073] According to embodiments of the subject matters disclosed herein, an inability of the agitator to homogenize the fermenter contents can be compensated for by the extraction process with the discharge system according to embodiments of the subject matters disclosed herein, and thereby the impurities can be uniformly incorporated into a liquid phase of the fermenter contents.

[0074] Embodiments of the subject matter disclosed herein allow reliable conveying of the fermenter contents removed from the fermenter in the discharge line (for example, without clogging the discharge line).

[0075] Embodiments of the subject matter disclosed herein thus allow a reliable removal of fermenter contents from the fermenter into a discharge line, particularly during a commissioning phase, in the event of abrupt seasonal changes in the fermentation substrate introduced into the fermenter, but also in the event of errors in the fermenter operation.

[0076] It should be noted that a pumping device as described herein is not limited to the dedicated entities described in some embodiments. Rather, the subject matter disclosed herein may be implemented in numerous ways at various granularities while still providing the specific functionality disclosed.

[0077] According to embodiments of the subject matter disclosed herein, any suitable entity (e.g., components, units, and devices) may be provided at least in part in the form of corresponding computer programs that enable a processor device to provide the functionality of the corresponding entity as described herein. According to other embodiments, any suitable entity as described herein may be provided in hardware. According to other, hybrid embodiments, some entities may be provided in software while other entities are provided in hardware.

[0078] According to one embodiment, the control device includes a processor device having at least one processor for executing at least one program element, which may correspond to a corresponding software module.

[0079] It should be noted that the embodiments described herein represent only a limited selection of possible embodiments of the present disclosure. Thus, it is possible to combine the features of various embodiments in a suitable manner, so that a person skilled in the art will consider a multitude of combinations of various embodiments to be disclosed with the embodiments explicitly disclosed here. Furthermore, it should be noted that terms such as "a" or "an" do not exclude a plurality. Terms such as "containing" or "comprising" do not exclude further features or method steps. Consequently, according to one embodiment, the term "comprising" or "containing" stands for "among other things." According to another embodiment, the term "comprising" or "containing" stands for "consisting of."According to one embodiment, the term "configured for" includes, among other things, the meaning "configured to".

[0080] It should also be noted that reference numerals in the claims should not be construed as limiting the scope of the claims. Furthermore, it should be noted that reference numerals in the description and the description's reference to the drawings should not be construed as limiting the scope of the description. Rather, the drawings illustrate only one exemplary implementation of a particular combination of several embodiments of the subject matter disclosed herein; any other combination of embodiments is equally possible and is to be considered disclosed in this application.

[0081] In summary, it remains to be stated:

[0082] Disclosed is a biogas plant comprising a plug-flow fermenter with a first discharge opening and a second discharge opening, a pumping device for removing fermenter contents through the first discharge opening and the second discharge opening and discharging the removed fermenter contents into a discharge line; and a control device configured to control the removal of fermenter contents through the first discharge opening and the second discharge opening into the pumping device and thereby adjust a quality of the removed fermenter contents in the discharge line. A method for operating a biogas plant and a corresponding computer program product effect the control of the removal of fermenter contents through the first discharge opening and the second discharge opening, thereby adjusting a quality of the removed fermenter contents in a discharge line.

Claims

Patent claims 1. Biogas plant comprising: a plug-flow fermenter with at least two discharge openings, wherein the at least two discharge openings comprise a first discharge opening and a second discharge opening; a pumping device for extracting fermenter contents through the at least two discharge openings and delivering the extracted fermenter contents into a discharge line; a control device configured to control the extraction of fermenter contents through at least two discharge openings into the pumping device and thereby adjust the consistency of the extracted fermenter contents in the discharge line.

2. Biogas plant according to claim 1, wherein the first discharge opening and the second discharge opening are arranged at a discharge end of the plug-flow fermenter, in particular wherein the first discharge opening and / or the second discharge opening are arranged at an end face of the plug-flow fermenter; and / or the first discharge opening is arranged below the second discharge opening.

3. Biogas plant according to claim 1 or 2, further comprising a longitudinally located agitator in the plug-flow fermenter.

4. Biogas plant according to one of the preceding claims, wherein the control device is configured to effect the removal of fermenter contents through the first discharge opening over a first period of time and to cause the removal of fermenter contents through the second discharge opening over a second period, wherein the first period and the second period are different.

5. Biogas plant according to one of the preceding claims, wherein the pumping device comprises a piston pump.

6. Biogas plant according to one of the preceding claims, further comprising an operating element with which a ratio of a fermenter content removed through the first discharge opening to a fermenter content removed through the second discharge opening can be set.

7. Biogas plant according to one of the preceding claims, further comprising a sensor device for determining the nature of the extracted digester contents in the discharge line; wherein the control device is configured to control the extraction of digester contents through the first discharge opening and the second discharge opening, in particular depending on the nature of the extracted digester contents in the discharge line determined by the sensor device.

8. Method for operating a biogas plant with a plug-flow fermenter having at least two discharge openings, wherein the at least two discharge openings comprise a first discharge opening and a second discharge opening, comprising the method: Controlling the removal of fermenter contents through the at least two discharge openings in order to adjust the quality of the removed fermenter contents in a discharge line.

9. The method of claim 8, wherein the removal of fermenter contents through the first discharge opening and the second discharge opening is carried out by a single piston pump; in particular, wherein in a first partial stroke of the piston pump The contents of the fermenter are removed through the first discharge opening, and in a second partial stroke of the piston pump, contents of the fermenter are removed through the second discharge opening, or vice versa.

10. A computer program product comprising a program element which, when executed on a processor device, is configured to control a method according to claim 8 or 9.

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