WO2018064993A1 - Multi-chamber system for generating biogas - Google Patents

Abstract

The invention relates to a multi-chamber system (1) for generating biogas from a fermentable substrate. By virtue of the special design of the multi-chamber system, which comprises at least two chambers, preferably three chambers (2, 3, 4), a method for generating biogas is provided, said method ensuring a continuous generation of gas in the event of a discontinuous supply of putrescible biomass. In the method for generating biogas in the multi-chamber system (1), a fermentation container (3) is provided in particular which takes multiple aspects into consideration while efficiently generating biogas, in particular the aspect of buffering the putrescible substrate in the event of an irregular supply of the required biomass. Additionally, the structure of the entire multi-chamber system (1) is designed such that the system can be erected compactly in a modular manner.

Description

 MULTILAMENT SYSTEM FOR GENERATING BIOGAS

The present invention is concerned with a multi-chamber system for the production of biogas, in particular with a method for the continuous operation of a biogas reactor, in which at least one container is provided which serves for buffering the fouling biomass.

Such biogas plants have become known from DE 10 2012 212 505 A1 in the prior art. This document discloses a method for operating a biogas plant with a plurality of biogas digesters, which are connected to each other with lines. The individual fermenters separated from each other are run in the so-called batch mode, which means that during the fermentation process, no further material is fed or removed from the fermentation tank. In order to continuously design the gas production, the individual fermentation tanks are filled with biomass and fermented with a time delay. In order to additionally improve the efficiency of such a biogas plant, a fermentation vessel freshly loaded with biomass is fed with a methane-sacred gas from an already gas-producing fermentation vessel in order to obtain a biogas usable for use in a combined heat and power plant. A disadvantage of such a biogas production, it is felt that in case of failure of one of the Fermentierbehälter the gas mixture no longer has the intended concentration of the individual components, for the freshly loaded Fermentierbehälter is provided. Another disadvantage is that the biomass is supplied to the fermentation tank in the dry state and it is thus unable to pump which adversely affects the efficiency of biogas production. Furthermore, it is disadvantageous that biomass from the beginning to the end of the fermentation process remains in one and the same Fermentierbehälter and must then be completely discharged, which makes the operating life of the entire biogas plant laborious, since an automatic filling and emptying process is not provided. Furthermore, it is disadvantageous in this type of biogas plant that the gas seals must be treated very carefully at the gates of each container to be really gas tight. As a disadvantage, it is further felt that the ratio of container volume to the gas production amount is relatively unfavorable. In addition, this type of biogas plants must always be filled with a specific biomass structure, for example shrubbery, which requires special attention in the selection of the biomass. In addition, in such cases, the distribution of bacteria is not necessarily evenly distributed, which has at least a negative impact on the time to usable gas production. Furthermore, the safety aspect is not entirely unproblematic with regard to a possible gas explosion, since in gas production a so-called explosion zone of the gas is traversed, in which the gas-oxygen mixture reacts explosively with accidental sparking.

Furthermore, from the document DE 10 2009 021 015 A1 a fermenter for the continuous production of biogas from biomass according to the principle of solid methanization known. This fermenter comprises at least one fermentation container which has a loading zone and a discharge zone at the beginning or end of the fermentation container. Between the two zones, a transport channel is arranged in which no active promotion of biomass takes place. The transport of the initially charged biomass occurs due to percolation flows in the transport zone of the fermentation tank. A disadvantage of this type of continuous gas production of the biogas plant, it is considered that the uniform transport of the entire biomass between the loading zone and the unloading zone is not guaranteed for all types of biomass. In particular, the residence time of the biomass in the reactor is comparatively large, which reduces the efficiency of the system.

Furthermore, WO 2009/000309 A1 discloses a biogas plant with anaerobic solids fermentation, in which a percolate is produced in several fermentation containers from the biomass, which is collected in a relatively large percolate container in which a biogas production process takes place and thus for better efficiency of the total biogas yield contributes. To accelerate percolate production and biogas production, the percolate collected in a percolate tank via a sewer system is sprayed again onto the freshly introduced biomass.

As a general disadvantage of the biogas plants mentioned above, it is felt that a continuous longer operating time is not guaranteed due to the different filling methods of the individual Fermentierbehälter and thus adversely affects the overall efficiency of the system.

Furthermore, as a disadvantage of the prior art in this field, it is felt that the functional design of the Fermentierbehälter together with the Biogas storage space is technically too complicated and can be created only by professionals. Furthermore, the maintenance of the known systems is not always easy, which also means that often maintenance must be performed, which can interfere with the continuous operation of the system sensitive.

Furthermore, it is disadvantageous in the prior art that the different types of biomass supplied do not find the necessary consideration, for example in biomass with a high proportion of sand and useless sludge, which often leads to a standstill of the entire system and removes the sand with costly measures what can not be done without interruption. With regard to the ever-increasing requirements for avoidance and

Reduction of waste and pollutants, it is essential to worry about the further degradation of energy-containing substances. For global political and economic reasons, new plant concepts and technologies should be developed to improve the overall balance. At rising

Substrate costs for biomass plants, it is important that the used

Substrates optimally prepared for the individual process stages conditions are processed in order to be able to be degraded with a significantly higher degree of degradation can. This aspect of better overall use of the used

Substrates are of great importance for the environment and the economic efficiency of the plants.

To the o.g. To overcome difficulties in the prior art, one aspect of the present invention is to make the entire structure of a biogas plant compact and technically less expensive. An important aspect of the present invention is to make the system safe for continuous long-term operation.

It is therefore an object of the present invention to provide a multi-chamber system for receiving and fermenting biomass, which is simple and straightforward in construction and ensures long-term continuous operation of the entire system.

This object is solved by the characterizing features of the main claims. Other features essential to the invention will be apparent from the subclaims and the description of the invention.

According to the invention, the process for the anaerobic production of biogas from a fermentable substrate with at least two separate fermentation containers, preferably three fermentation containers, with lines interconnected, characterized by the following method steps:

 - Continuously introducing a treated biomass (substrate) in at least a first container in which the biomass fermented in a mesophilic stage;

 - Continuous transfer of the biomass (substrate) of the first Fermentierbehälters in at least one second Fermentierbehälter in which the biomass (substrate) ausärt under thermophilic process conditions; and

 - Continuous transfer of the thermophil digested biomass (substrate) in at least one other fermentation to the residual outgassing of the substrate at adjustable temperatures between 35 ° C and 60 ° C, which are dependent on the respective substrate.

It is advantageous that at least one Fermentierbehälter than

Buffer tank is used.

Another advantage is the fact that at least one container as

Main fermenter of the supplied biomass is used.

It is also advantageous that the amount of gas generated is stored in a gas storage space above the at least two fermentation tanks.

It is also advantageous that at least one desulfurization device is arranged between the at least two fermentation containers and the gas storage.

It is furthermore advantageous that the fill level of the individual fermentation containers, in particular of the buffer fermentation container, can be varied.

Another advantage is that the filling of at least two

Fermentierbehältern means of at least two independent

Feeders is performed, of which at least one Feeding device in the first fermentation and at least one feeding device is guided in the buffer tank.

It is also advantageous that after fermentation of most of the biomass, this is transferred to at least one buffer tank.

Another advantage is that in the cover between

Fermentier and the gas storage a water-filled siphon is arranged.

It is also advantageous that the fully ausgegorene substrate is fed in the main thermophilic fermenter a solid-liquid separation device by means of pumps, in which the dry matter is separated from the liquid mass.

It is also advantageous that, in the event of failure of a fermentation container, the supply and discharge lines can be closed and opened with suitable sliders in order to control the substrate flows in the piping system and divert them to other fermentation tanks in order to meet the requirements for achieving a continuously efficient long-term production of biogas ,

As it is also advantageous that in case of failure of the thermophilic

Hauptfermenters the mesophilic precursor can be heated to a temperature in the thermophilic areas.

It is also advantageous that the gas supply lines between the

Fermentierbehältern and the gas storage space are dimensioned so that it is supplied at overflow of at least one Fermentierbehälters, the amount of substrate of the overflow to the space enclosed by the container ring of the spacer.

The multi-chamber system according to the invention for the anaerobic production of biogas with at least two separate containers, preferably three containers, which are connected to each other lines, is characterized characterized in that at least three chambers are arranged in a compact frame construction, of which at least one chamber serves as a buffer space for the auszufaulende substrate and between the fermenters and the gas storage space at least one annular spacer is arranged that serves for securing the substrate when overfilling at least one fermenter ,

It is advantageous that each fermentation tank has at least one over the entire length of the fermentation tank extending agitator.

Another advantage is seen in the fact that each fermentation tank is connected at least to a feed line and at least one suction line, it being advantageous that the feed line is arranged at the beginning and the suction line at the end of the fermentation tank.

Furthermore, it is advantageous that the at least three fermentation containers are arranged in a frame construction whose plan view is preferably approximately square and is preferably made of concrete or equivalent material (eg masonry). For a variety of

Fermentierbehältern, for example, twelve fermentation, it is not mandatory to arrange these fermentation next to each other, but it makes sense to arrange these twelve fermentation, in two groups of six juxtaposed Fermentierbehälter behind the other and to arrange a cup-shaped gas space.

Another advantage is that above the masonry at least one gas container is arranged.

It is also advantageous that above the masonry at least one

Device for holding substances containing sulfur in the biogas space

is arranged.

Furthermore, it is advantageous that within each individual fermentation container at least one sand discharge device is arranged, and it is advantageous has the effect that the bottom of each fermentation container has at least one trough and the surface of the bottom of each fermentation container is inclined and the at least one slope opens into at least one trough.

Another advantage is seen in the fact that at least one nozzle for spraying the surface of the biomass is arranged at foaming in the upper region of each fermentation container.

Another advantage is that the connection of the multilayer film to form the gas space above the Fermentierbehälter is formed by means of a cross-sectionally C-shaped groove, which receives a stretchable pressure hose.

Further, it is advantageous that the passage of the shaft of the agitator is surrounded by the end wall of the Fermentierbehälter of a sealing device having at least one lip seal and at least one housing for forming at least one cavity.

Another advantage is that the entire system is modular

Construction is constructed.

The multi-chamber system is preferably created in the modular system in such a way that the individual parts and pre-assembled modules fit into a transport system, such as in one or more shipping containers. At the construction site this is then set up and mounted with little tools and little technical effort. The proportion of auxiliary materials and materials such as concrete anchors and foundations or ground anchors is also minimized. Optionally, all necessary tools and assembly tools can complete the delivery.

With the multi-chamber system according to the invention, the heart of a biogas plant is provided, which manages with low production costs, nevertheless offers a high level of operational reliability against interruptions, leaks and accidents. Not only can it be easy and quick to set up, but also the operation and maintenance can be done quickly, safely and without significant interruptions to operations by qualified personnel. Due to the simple modular design of the system, all moving parts are easily accessible and easy to handle and can be easily expanded.

Further advantageous and essential features of the invention are the

Subclaims and the description can be found.

In the following, the modular system according to the invention for the construction of a biogas container for the fermentation of biomass is explained in more detail with reference to drawings. It shows

Fig. 1: a schematic plan view of an inventive

 Multi-chamber system (1);

2 shows a schematic side view of the multi-chamber system (1), in which over three fermentation containers (2,3,4) the gas storage space (5)

 is arranged;

3a shows a schematic side view of the gas storage space (5) with a detail "A 'representing the connection of the multilayer film (42, 42') to the spacer and intermediate element (11);

3b: an enlarged view of the detail "A" of Figure 3a;

4 shows a simplified technical representation of a part of the agitator (12) in the installed state in one of the fermentation container (2, 3, 4); 5 shows a simplified technical representation of the passage of

 Drive shaft (27) of the agitator (12) in the end wall (25) of the

 Masonry of one of the fermentation tanks (2,3,4) with a controllable shaft sealing device (35);

6 shows a schematic side view of one of the three fermentation containers (2, 3, 4) with a sand discharge device (16);

Fig. 7 is a schematic plan view of the three fermenting tanks (2, 3, 4) with a foam sprinkler system (44) over each of the three firing tanks with a plurality of nozzles (73);

Fig. 8 is a schematic sectional view of a pipe passage (74) through the masonry (.25) of the fermentation container (2,3,4).

Fig. 1 shows a simplified schematic representation of a

Embodiment of the multi-chamber system according to the invention 1. The multi-chamber system 1 is on a rectangular ausbetonierten

Frame construction 13 of a masonry 14 constructed whose floor plan is formed substantially square. In the frame construction 13 in the present embodiment, three elongated Fermentierbehälter (2,3,4) are arranged, the outer walls consist of a masonry 14 which is typically either cast from concrete or built in a conventional manner in brick construction. The almost square shape of the

Frame construction 13 is therefore useful, because thereby the patch

Distance element 11 is substantially circular and the overlying gas storage space 5 may be spherical in shape, creating an optimal

Volume-diameter ratio is given. The annular spacer 11 is made in the present embodiment of a metal, which on the one hand extends the life of the system and on the other hand is practical for the connections of the various pipes, in particular the Gas extraction lines 10, 10 'with a flange easily to the

Distance element 11 is flanged from metal. Generally that is

Spacer element 11 to be designed so that at least the inside to the gas is corrosion resistant or coated with a corrosion protection. The three fermentation containers 2, 3, 4 are formed by two elongate dividing walls 18, 18 '. Above the three Fermentierbehälter 2,3,4 pipes 19, 19 'are arranged, which connect the Fermentierbehälter 2,3,4 with each other, wherein the one end of the pipe 19 in the first Fermentierbehälter 2 and the other end in the fermentation 3 and the an end of the pipe 19 'into which leads into the fermentation tank 4, so that alone thereby the individual

Fermentierbehälter 2,3,4 are at least gas technology with each other. In addition, the individual fermentation containers 2, 3, 4 are connected to one another via the pressure lines 7, 7 'and the suction lines 8, 8', 9, whereby certain method steps for the diversion of the substrate streams and biogas production are made possible. At a suitable location on the side of the

Frame construction 13 are arranged between the pressure line 7,7 'and the suction 8.8' in each case a pump 20,20 ', depending on the rule of the respective method, the partially or completely fermented pumpable hydrogenated

Transport biomass (substrate) into the fermenting container 2, 3, 4 provided for this purpose.

In a first method step, the first fermentation container 2 via a so-called Stopfschnecken line 6 to about two-thirds of the

Volume filled so that the plug screw is always under liquid and no gas can escape. The temperature in this first

Fermentierbehälter 2 is preferably in the mesophilic region at about 38 ° C.

In a second process step, the partially fermented biomass (substrate) is then passed through the line 8 via the pump 20 'and the line 7 in the third main fermentation vessel 4 for thermophilic digestion at about 55 ° C after a mesophilic fermentation. The filling of the thermophilic Fermentierbehälters 4 is then carried out continuously at short intervals, approximately every hour, with the same biomass.

In a further third process step, the

Fermentierbehälter 3 via the pump 20 from the previously filled

Fermentierbehälter 4 filled, so that in this fermentation 3 is a residual outgassing of the substrate. The fully fermented substrate (biomass) is then stored in this fermentation tank 3 until it is supplied by a conveyor 20, 20 'of the solid-liquid separation apparatus (not shown) which separates the dry matter of the substrate from the liquid mass. The solid-liquid separation device is outside the multi-chamber system. The feed lines 6, 6 'can remove the treated hydrogenated biomass from one and the same source or from different sources. Between the two pump inputs of the pumps 20,20 'there is a direct connection via the line 9, whereby in case of failure of a pump, the other pump can do the job, which is essential to

Operational safety of the system contributes.

In order to drive the multi-chamber system 1 continuously, it is necessary that the fermentation tanks 2 and 4 are continuously and continuously supplied with a biomass (substrate). Therefore, the fermentation tank 3 can be driven variably on one third of the container volume, so that the two

Fermentierbehälter 2 and 3 are driven so far empty that in each case at least one third of the container volume can be filled. As a result, the fermentation tank 3 takes over a buffer function for the biomass to be refilled, which may be of importance particularly at times of discontinuous deliveries of the biomass, for example on weekends.

Since the freshly prepared biomass via the lines 6,6 'in the

Fermentierbehälter 2 and 3 is introduced, this is amassed up to about one-third of the container length on this side of the Fermentierbehältiereingangs. With the pump 20 can then almost ausgegorene biomass by switching a Slider (not shown here) are spent in the rear part of the fermentation tank 3 via the pressure line 7. Thus, it is possible to pump alone with the pump 20 from the front part of the fermentation tank 3, in which also the freshly introduced biomass is stored, thus ensuring a continuous supply of the fermentation tank 2 with fresh biomass. Now, if the majority of the biomass is completely consumed, can be switched by means of a slider, so that the ausgegorene biomass of the

Fermentierbehälter 4 is pumped back into the front of the fermentation tank 3. By this procedure, moreover, a sufficient buffer function is achieved, which is important in waste recycling plants by irregular substrate deliveries to the process continuously over a longer period, about one year, without

To be able to drive through interruptions.

In case of failure of the first mesophilic stage in Fermentierbehälter 2, the system can replace the fermenter 3 via the supply line 6 'from the

Source pump 21 are supplied. In this case, the

Fermentierbehälter 3 the first mesophilic process stage and the

Fermentierbehälter 4 remains in its thermophilic mode of operation.

Immediately before each Fermentierbehältern 2,3,4 is one each

Slider device (not shown here) arranged so that everyone

Fermentierbehälter 2,3,4 alone can be switched off separately, i. can be taken out of the multi-chamber system 1 to

For example, to carry out maintenance. The gas range of the fermentation tank 2 can be separated by means of a slide (not shown here), so that maintenance of the fermentation tank 2 without

Business interruption is possible. In this case, the substrate fermented in the fermentation tank 3 is fed directly into the solid-liquid separation apparatus (separation) with the aid of one of the pumps 20, 20 'and further processed.

Since a concrete ceiling 33 is located above the fermentation tanks 2, 3, 4, and liquid condensate is in the gas storage tank 5 above it. Metal ring container 11 is located in the concrete ceiling of the fermentation 2 and 4 each have a siphon 17 is arranged, which is always filled with water to exercise a gas-tight function

In the event that the main Fermentierbehälter 4 should fail, this failure naturally has significant consequences for gas production. In order to avoid such a situation as far as possible, the fermentation tank 2 is brought from the mesophilic to the thermophilic state, so that this

Fermentierbehälter 2 assumes the function of the main Fermentierbehälters 4. In such a procedure, it must not be forgotten that the necessary biomass hydrogenation process is carried out, i.e. that the biomass must remain at about 55 ° C for at least 24 hours in order to avoid possible nucleation within the biomass. This

Requirement is ensured in the procedure described above. In this case, the fermentation tank 3 is filled via the supply line 6 'from the source 21 with fresh biomass. Following this, the second pump 20 'pumps the biomass from the fermentation vessel 4 into the fermentation vessel 2 via the second pressure line 7', so that subsequently the fermentation vessel 4 can be easily maintained. Due to the diametrically opposite pumps 20,20 'between the suction and discharge lines 7,7' and 8,8 'it is possible by switching or sealing corresponding lines, in case of failure of one of the two

Pumps 20,20 'to maintain the operation of the plant, without the

continuous filling of the fermentation tank 2, 3.4 and the so

related gas production.

As a result of a possible high sand input into the fermentation tank 2,3,4, it is necessary to lead the registered sand continuously or from time to time from the fermentation tanks 2,3,4, so as to both the mechanical operation of the agitators 12 and the biological fermentation process not to endanger. This purpose is served by the sand discharge device 16, which will be described in more detail below. The agitators 12 of the individual fermentation containers 2, 3, 4 extend over the entire length of the fermentation containers 2, 3, 4, whereby the entire biomass located in the respective fermentation containers 2, 3, 4 is detected by the circulation. The individual agitators 12 can be moved at different speeds and, depending on requirements, individual ones can be switched on and off.

2 shows a schematic side view of the multi-chamber system 1, in which the gas storage space 5 is arranged above the three fermentation containers 2, 3, 4. Between the fermentation containers 2,3,4 and the gas storage space 5, a spacer 11 is arranged, which is the basis for the construction of the

Gas storage room 5 represents. This spacer 11 is usually formed as a circular ring made of metal or equivalent material. Among other things, the spacer element 1 1 serves the operational safety of the entire system, because at overflow by foaming the biomass (substrate) or overfilling the fermentation tank 2,3,4 with biomass, the space enclosed by the spacer element 1 1 forms a catch basin for by the generously sized gas passages 22 through the covers 33 of the fermentation tank 2,3,4 flowing biomass, which then spreads to the not yet completely filled fermentation. Through this

Safety measures ensure that an accident is buffered and thus does not completely interrupt the operation of the system. The bearings 24 of the agitators 12 are arranged approximately in the middle of the respective fermentation container 2,3,4, in order to ensure that when completely filled

Fermentierbehälter the entire biomass is mixed homogeneously.

Furthermore, the spacer 11 offers the possibility of flanging gas connection lines by means of Edelstahlflanschplatten to the container ring 1 1. Between the container ring 11 and the flange plates is a so-called inliner, a plastic film, for the galvanic separation possible different

electrochemical potentials and arranged as corrosion protection. Above the spacer element 11, a desulfurization device 15 is arranged, which as Anlagungsfläche for desulfurization of the generated biogas or methane is used.

3a shows a schematic side view of the upper portion of the multi-chamber system 1 with a detail "A", the enlarged

Scale represents the connection of the spacer element 1 1 to the multilayer film 42,42 'to form the gas space 5 of the multi-chamber system 1, wherein the gas storage space is formed spherical shell and the spacer element 11 annular. On the cover plates 33 of the fermentation 2, 3.4, the spacer 11 is gas-tight and waterproof. At the top of the

Spacer 11 is the multilayer film 42, 42 'with a special

Fastening device 43 arranged, which is shown in an enlarged scale in the figure 3a. The fastening device 43 consists essentially of a cross-sectionally C-shaped groove 45, which is fastened with Versch raubungen 46 to a 47 of the spacer 11 1. In the groove 45, a flexible compressed air hose 48 is inserted. The end portions of the multi-layer cover 42,42 'of the gas space 5 is also inserted between the walls of the C-shaped groove 45 and the compressed air hose 48, so that at a

Pressurization of the compressed air hose 48 expands this and the multilayer film 42,42 'presses on the transformations of the C-shaped groove 45, so that the gas space 5 is sealed gas and waterproof to the environment.

FIG. 4 shows, on an enlarged scale, a section of the entrance area of one of the fermentation tanks 2, 3, 4, wherein the end wall 25 of a

Fermentierbehälters has an opening 26 through which the

Drive shaft 27 of the agitator 12 protrudes. The drive shaft 27 'is supported by supports 28 or so-called emergency storage, within the fermentation tank 2,3,4, wherein the agitator 12 over the entire length of the

Fermentierbehälters 2,3,4 extends. On the drive shaft 27 'blades 29 are arranged at intervals and angularly offset, which mix the registered substrate. For reloading dry substance or non-free-flowing biomass, in at least one of the fermentation containers, a guide tube 30 is at a predetermined angle (a) to the end face of the fermentation container Stopfschnecke arranged with its one end into the interior of the fermentation tank and at its other end is a gear 31 with a

Angled motor 32. Furthermore, with one end in the upper region of the fermentation container, additional filling tubes 40, 41 protrude into the fermentation container, of which one filling tube 40 is for introducing fresh biomass and the other filling tube 41 is for supplying liquids, for example liquid percolate is.

FIG. 5 shows a section of the region of the shaft passage 26 through the end wall 25 of a fermentation container. The shaft 27 is supported by a bearing 24 on this side. Shortly after passing through the end wall 25, the shaft 27 has a flange 34, to which a tubular shaft 27 'is flanged, wherein the tubular shaft 27' carries the blades 29 of the agitator 12. Within the opening 26 of the end wall 25, a device 35 for sealing the shaft passage of the agitator shaft 27 is arranged. This shaft seal is extremely important for the smooth operation of the agitator

Agitator shaft 27 is a hardened sleeve 37 made of steel non-slip. On the surface of the sleeve 37 slide at least two sealing elements 51, which already cause a seal of the stirring shaft. Between these sealing elements 51 and further sealing elements 51 'an annular space 39 is arranged, from which a control line 52 leads away, can be removed via the possible accumulations of permeated sand and water residues. The sealing device 35 is fastened with a flange plate 53 on the outer wall of the end wall 25, so that thus the opening 26 of the end wall is closed to the outside. To the sealing elements 51, 51 'around is a

Housing 54 arranged that in the immediate vicinity of the stirring shaft 27 a

Abrasive sheet 55, to which a flexible lip seal 56 bears with slight pressure, by displacement of the mounting ring 57 on the

Agitator shaft 27 is generated more or less firmly. By means of this lip seal 56, a large part of the resulting sand and sludge is prevented from reaching the sealing elements 51. In the event that anyway sand and / or mud should get into the interior of the housing 54, are at these Cavity 49 two purge lines 58,58 ', wherein a flushing liquid is introduced through the conduit 58 into the cavity and is discharged via the line 58' together with possible sand and sludge entry again. The inlet and outlet 58,58 'is provided at the output with a shut-off valve 59,59', which are actuated if necessary.

The shaft 27 is supported at one end by the bearing 24. At the end of the shaft 27, a transmission 31 is arranged with a perpendicular thereto motor 32. The transmission 31 together with the motor 32 is relieved by a support 38, wherein the support 38 is fixed with its one end to the masonry of the wall 25 of the fermentation container and with its other end to the transmission 31. With the support 38, the torque acting on the agitator shaft 27 is intercepted.

FIG. 6 shows a schematic cross-sectional representation of a

Fermentierbehälters 2,3,4 with a Sandaustragvorrichtung 16. Die

Sandaustragvorrichtung 16 is particularly important for the long-term operation of the entire system, because usually a not inconsiderable proportion of sand and soil is introduced with the fresh biomass in the Fermentierbehälter, which leads to considerable disruption in the circulation of biomass in Fermentierbehälter after a long time. Approximately in the middle of the Firmentierbehälters the agitator 12 is arranged with the blades 29 on the agitator shaft 27 which rotates counterclockwise. The bottom 60 of the fermentation container has a certain predetermined slope, which extends to a trough 61. As a result of the rotation of the agitator 12 and gravity of the possible sand or mud is guided into the trough 61, in which at least one suction pipe 62 leads, which can be applied via a valve 63 with vacuum if necessary, so that the possible sand input is sucked and is first stored in a buffer 64. The buffer 64 is connected via a line 66 to the main memory 65, in which the sand is stored up to a predetermined amount. After the main memory 65 has reached a predetermined level, this is at the bottom by means of a flap 67th opened so that the main memory 65 can be completely emptied. The accumulated sand 68 may then be removed by a wheel loader or otherwise. At the upper end of the main memory 65 is a suction line

69 which is connected to a vacuum pump 70. The vacuum pump

70 generates the necessary vacuum for sucking off the trough 61 filled with sand. Over the entire bottom 60 of a fermentation container, a plurality of troughs 61 extend, which is symbolized by the rectangular compartments 61 '. In the inclined bottom 60, a heater 71 is arranged, which is necessary for controlling the temperature of ausfaulbaren biomass.

FIG. 7 shows a schematic plan view of the fermenting containers 2, 3, 4, above which a sprinkler system 72 having a multiplicity of nozzles 73 is arranged. The sprinkler system serves to prevent or at least reduce the possibility of foaming on the surface of the outgrowing biomass. In the event that shows a large amount of foam on the surface of the outgrowing biomass, the respective container is 2,3,4 the

Sprinkleranlage turned on, so that from the nozzles 73, a liquid, usually water, exits and spreads over the foam formed, whereby the foaming is at least reduced.

FIG. 8 shows a schematic sectional view of a pipe feedthrough 74 through the masonry of an end wall 25 of one of the fermentation containers 2, 3, 4. A pipe penetration through the masonry of a fermentation tank 2,3,4 is fundamentally problematic, because on the one hand the tightness to the outside and on the other hand, the ease of installation of the pipe feedthrough must be guaranteed. In the present embodiment of a pipe feedthrough through a concrete wall 25, the manhole lining 75, usually a plastic raw r, is cast in the migratory position in the masonry. The steel pressure pipe 76 to be installed has a flange 77 on both sides, the diameter of which corresponds approximately to the inside diameter of the shaft lining 75. On the outside of the pressure tube 76 is at least one guide tube 78 with a thereto

welded threaded rod 79 arranged so that between the Masonry 25 and a flange plate 80 made of steel, a gap with the distance a is formed. The gap 81 serves to accommodate

Sealing material 82, 82 '. The sealing material 82 'is for example a

Silicone adhesive, which is introduced after formation of a gap between two circularly applied elastic adhesive tapes 82, preferably made of foam. The diameter of the flange plate 80 is to be chosen so that sufficient space for the necessary sealing material is formed. As a result of firmly welded to the pressure tube 76 and the flange plate 80 threaded rods 79, can with a non-pressure tube 76 mounted counter-plate 84, through which the threaded rod 79 protrudes, the flange plate 80 by means of a

Threaded nut 83 or similar fastening means against the masonry 25 are pulled, whereby a reliable seal between the masonry 25 and the flange plate 80 due to the inserted sealing materials 82, 82 'is formed. With the flanges 77 then further pipe connections can be made.

In summary, it may be stated that the present invention introduces a multi-chamber system 1 for producing biogas from a fermentable substrate. Due to its special design with at least two chambers, preferably three chambers 2, 3, 4, a process for producing biogas is made possible, which ensures continuous gas production in the case of discontinuous supply of the digested biomass. The method for producing biogas in the multi-chamber system 1 provides, in particular, a fermenting tank 3 which takes into account several aspects of efficient biogas production, in particular the aspect of buffering the digested substrate in the case of irregular supply of the required biomass. Furthermore, the structure of the entire multi-chamber system 1 is designed so that it can be made compact in a modular design, whereby both the capacity of the biomass to be fermented and the production of usable biogas can in principle be arbitrarily extended. Overall, a biogas plant is presented with the present multi-chamber system 1, which has a high degree of efficiency with a small construction volume on a small construction area, ie that the ratio of biogas yield to the construction volume of the plant is comparably large.

Claims

1. A method for the anaerobic production of biogas from a fermentable substrate with at least two separate fermentation containers, preferably three Fermentierbehälter (2,3,4), which are interconnected with lines (7,8,9), characterized by the following method steps:  continuously introducing a treated biomass (substrate) into at least one first container (2) in which the biomass is fermented in a mesophilic stage;  continuous transfer of the biomass (substrate) of the first fermentation container (2) into at least one second fermentation container (4) in which the biomass (substrate) is fermented under thermophilic process conditions; and  - Continuous transfer of the thermophil digested biomass (substrate) in at least one other fermentation vessel (3) for residual degassing of the substrate at adjustable temperatures between 37 ° C and 57 ° C, which are dependent on the respective substrate. 2. The method according to claim 1, characterized in that at least one fermentation container (3) is used as a buffer container. 3. The method according to claim 1, characterized in that at least one container (4) is used as the main fermenter of the supplied biomass. 4. The method according to claim 1, characterized in that the amount of gas generated in a gas storage space (5) above the at least two fermentation tanks (2,3,4) is stored. 5. The method according to claim 1, characterized in that between the at least two Fermentierbehältern (2,3,4) and the gas storage (5) at least one desulfurization device (15) is arranged. 6. The method according to claim 1, characterized in that the level of the individual Fermentierbehälter (2,3,4), in particular of the buffer Fermentierbehälters (3) is driven variable. 7. The method according to claim 1, characterized in that the filling of at least two Fermentierbehältern (2,3) by means of at least two independent feed means (6,6 ') is carried out, of which at least one feed device (6) in the first fermentation container ( 2) and at least one  Feeding device (6 ') in the buffer container (3) is guided. 8. The method according to claim 1, characterized in that after fermentation of the largest part, about two thirds of the digestate (substrate), this is transferred to at least one buffer tank (3). 9. The method according to claim 1, characterized in that in the cover between Fermentierbehälter (2,3,4) and the gas storage (5) at least one filled with water siphon (17) is arranged. 10. The method according to claim 1, characterized in that the ausgegorene substrate is fed from one of the Fermentierbehälter a solid liquid separation device. 11. The method according to any one of the preceding claims, characterized characterized in that in case of failure of one of the Fermentierbehälter (2,3,4) the inlet and outlet lines (6,6 ', 7,8) are closed to divert the substrate streams. 12. The method according to claim 1, characterized in that in case of failure of the thermophilic Hauptfermenters (4), the mesophilic precursor (2) is heated to a temperature in the thermophilic regions. 13. The method according to any one of the preceding claims, characterized in that the gas supply lines (22) between the Fermentierbehältern (2,3,4) and the gas storage space (5) so  are dimensioned so that they overflow at least one  Fermentierbehälters (2,3,4), the amount of substrate of the overflow to the container ring (11) enclosed space can be supplied 14. Multi-chamber system (1) for the anaerobic production of biogas with  at least two separate containers (2,3,4), preferably three containers, which are interconnected by lines (7,8,9), characterized by at least one chamber which serves as a buffer space (3) for the substrate auszufaulende and between the at least two fermenters (2,3,4) and the gas storage space (5) is arranged at least one annular spacer element (11) that serves for securing the substrate when overfilling at least one fermenter (2,3,4). 15. Multi-chamber system according to claim 15, characterized  characterized in that each fermentation container (2,3,4)  at least one over the entire length of the fermentation container (2,3,4) extending agitator (12). 16. Multi-chamber system according to claim 15, characterized in that each fermentation container (2, 3, 4) is connected to at least one supply line (6) and at least one suction line (8). 17. Multi-chamber system according to claim 15, characterized  in that the at least three fermentation containers (2, 3, 4) are arranged in a frame construction (13) whose plan view is preferably square and is preferably made of concrete or equivalent material (eg masonry) (14). 18. Multi-chamber system according to claim 15, characterized  characterized in that above the masonry (14) at least one gas container (5) is arranged. 19. Multi-chamber system according to claim 15, characterized  characterized in that above the masonry (14) at least one device (15) for receiving sulfur-containing substances is arranged. 20. Multi-chamber system according to one of the preceding claims,  characterized in that within each individual fermentation container (2,3,4) at least one sand discharge device (16) is arranged. 21. Multi-chamber system according to one of the preceding claims,  characterized in that in the upper region of the  Fermentierbehälters (2,3,4) at least one nozzle (73) for spraying the surface of the biomass is arranged on foaming. 22. Multi-chamber system according to one of the preceding claims,  characterized in that the bottom (60) of each  Fermentierbehälters (2,3,4) has at least one trough (61). 23. Multi-chamber system according to one of the preceding claims, characterized in that the surface of the bottom (60) of each fermentation container (2,3,4) formed obliquely contoured is and the at least one slope (60 ') in at least one trough (61) opens. 24. Multi-chamber system according to one of the preceding claims,  characterized in that the connection of  multilayer film (42,42 ') for forming the gas space (5) above the fermentation container (2,3,4) by means of a C-shaped groove (45) is formed, which receives a stretchable pressure hose (48). 25. Multi-chamber system according to one of the preceding claims,  characterized in that the passage of the shaft (27) of the agitator (12) through the end wall (25) of the fermentation container (2,3,4) by a sealing device (35) is surrounded, the at least one lip seal (56) and at least one Housing (54) for forming at least one cavity (49) comprises. 26. Multi-chamber system according to one of the preceding claims,  characterized by a pipe lead-through (74) having a flange plate (80) and a threaded rod (79) attached thereto, by means of which a tension is exerted on the flange plate. 27. Multi-chamber system according to claim 15, characterized by a modular structure of the system.