DE20319847U1 - Large scale fermenter, to produce a biogas from a relatively dry biomass, has a vertical framework on the base plate to support a gas-tight film shrouding with a sealed loading/unloading opening - Google Patents

Abstract

A large-scale fermenter (2) to generate a biogas from a biomass, comprising a container (20) to hold the rotting mass with an opening (30) to insert and remove the mass which is closed by a gas-tight flap (32), and a gas-tight base plate (22) carrying a stable and vertical framework (24), to support a gas-tight film shrouding (44), where the shrouding gives a gas-tight seal for the biomass container, is new. A large-scale fermenter (2) to generate a biogas from a biomass, using solid matter methanation, comprising a container (20) to hold the rotting mass with an opening (30) to insert and remove the mass which is closed by a gas-tight flap (32), and a gas-tight base plate (22) carrying a stable and vertical framework (24), to support a gas-tight film shrouding (44), where the shrouding gives a gas-tight seal for the biomass container and the opening around the outer sides of the framework and the base plate. The shrouding film (46) is of an elastic film material, or it is a double film with a gas space between the film layers.

Description

The The invention relates to a large fermenter for Generation of biogas from biomass and a biogas plant for production of thermal, electrical and / or mechanical energy Biogas with such a large fermenter.

So far, the biogas technology has mainly focused on the "wet fermentation" of liquid manure and / or biowaste from the municipal sector. Renewable raw materials with high dry matter contents (eg maize silage) or mash can only be admixed to a limited extent in these processes. The so-called "dry fermentation" makes it possible to methanize pourable biomass from agriculture, biowaste and communal care areas without transferring the materials into a pumpable, liquid substrate. It can be fermented biomasses with up to 50% dry matter content. This dry fermentation process is, for example, ind EP 0 934 998 described.

at the "dry" fermentation becomes the one to be fermented Material not in a liquid Phase stirred in, like the liquid fermentation of biowaste the case is. Instead, this is brought into the fermenter Fermentation substrate constantly moist held by the percolate withdrawn at the bottom of the fermenter and above the Biomass sprayed again becomes. This ensures optimal living conditions for the bacteria. at The recirculation of the percolate can additionally regulate the temperature be, and there is a possibility of additives for one Add process optimization.

Out WO 02/06439 is a bioreactor or a fermenter in the form of a Prefabricated garage known, according to the principle of dry fermentation is operated in the so-called batch process. This is after Inoculation with already fermented material becomes the fermentation substrate filled with wheel loaders in the fermenter. The garage-shaped fermentation tank is closed with a gas-tight gate. The biomass is under exclusion of air fermented, there is no further mixing and it is no additional Material supplied. That from the fermentation Sipping percolate is over withdrawn a drainage channel, stored in a tank zwischenges and again for humidification the fermentation substrate sprayed. The fermentation process takes place in the mesophilic temperature range at 34-37 ° C, the tempering takes place by means of a floor and Wall heater.

The biogas can be produced in a combined heat and power plant of electricity and heat be used. So that always enough biogas for the combined heat and power plant disposal stands, in the dry fermentation plant several fermentation tanks in time operated offset. At the end of the residence time, the fermenter room Completely emptied and then refilled. The fermented substrate is fed to a post-composting, so that a conventional compost comparable organic fertilizer is produced.

A such plant is running currently in Munich in the trial mode.

Of the from WO 02/06439 known fermenter in the manner of a prefabricated garage let yourself not easily enlarge if Systems with larger capacity are desired. A simple magnification, z. B. an extension the prefabricated garage fermenter leads to larger thermal Tensions leading to leakage problems in the gas-tight concrete to lead can.

outgoing It is therefore the object of the fermenter known from WO 02/06439 to provide the present invention, a large fermenter, a can absorb multiple of the biomass. Next it is the task of Invention a biogas plant with one or more such large fermenters specify.

The solution This object is achieved by the features of claims 1. 11 or 19.

By the case in the form of a gas-tight film, the gas tightness necessary for the large fermenter produced. The biomass is on a bottom plate with a stable Surrounding, which extends approximately vertically in height, stored. The bottom plate is gas-tight, while the stable lateral enclosure does not need to be gas-tight but merely serves the biomass stored in the large fermenter to keep. The big fermenter is preferably over the loading and unloading by wheel loaders and the like passable.

The gastight envelope is gas-tight connected to the loading and unloading and as well with the bottom plate. It is important that the gas-tight envelope outside of the stable enclosure passed and gas-tight connected to the bottom plate. Through this external arrangement the gas-tight envelope is guaranteed that the sensitive case at Loading and unloading the large fermenter not damaged becomes.

This basic idea is also fulfilled if the gas-tight envelope does not originate from the base plate, but is connected in a gas-tight manner to the outside of the stable enclosure with the stable enclosure. Of course, it is then important that Be rich of stable enclosure below the line of attack of the gas-tight envelope is gas-tight.

A Another alternative is that the lateral enclosure gas-tight accomplished is and the gas-tight envelope is attached to the upper edge of the lateral enclosure gas-tight. This also ensures that that at Loading and unloading the large fermenter through this intended vehicles no damage to the gastight film he follows.

One Scratches on the stable enclosure during loading and unloading is not critical, since the stable enclosure opposite mechanical stress is much less sensitive than the thin one gas-tight foil.

According to one preferred embodiment of Invention, the gas-tight envelope is an elastic film, whereby on the one hand pressure fluctuations of the generated biogas easily can be intercepted and additionally in To a certain extent a variable storage space for the generated biogas provided is (claim 2).

According to one Another advantageous embodiment of the invention is the gas-tight Shell as Double foil with a gas space between the two foils executed. hereby elevated the security, since a leak in one of the two slides still does not necessarily lead to a gas leak (claim 3).

According to one Another advantageous embodiment of the invention is the gap between the two foils filled with a gas, creating a thermal Isolation of the large fermenter provided by the environment. Come as insulating gas in particular air or exhaust gas from the CHP in question. In warmer regions can the gas space in the double foil additionally as a solar air collector be used for providing dry air (claim 4).

According to one Further advantageous embodiment of the invention is the cavity Exhaust gas flows through between the two films of the double film, the during the combustion of biogas, for example, in a CHP produced. This is particularly advantageous in cold areas, as a result greater heat loss of the fermenter is prevented. Another advantage of using of exhaust gas in the gas space of the double film is that the Exhaust gas is inert. Should it damage the inner or the outer film come, can form no explosive ambient air / gas mixture (Claim 5).

According to one Another advantageous embodiment of the invention is in the cavity thermal insulation material between the two foils of the double foil, z. As rock wool, introduced to the large fermenter thermally from the Isolate environment (claim 6).

According to one further advantageous embodiment of the invention includes the and discharge opening with the bottom plate off, which is very beneficial when it comes to a drivable large fermenter act (claim 7 and 8).

According to one further advantageous embodiment of the invention is in the and discharge opening fitted a flap frame, i.e. the flap for gas-tight sealing of the large fermenter seals against the Flap frame off and the gas-tight envelope is gas-tight connected to the flap frame (Claim 9).

According to one Another advantageous embodiment of the invention is the gas-tight Shell outside at least partially surrounded by a durable protective cover. This can easily be an unintentional or wanton damage the gas-tight envelope be prevented (claim 10).

A According to the invention biogas plant according to claim 11 one or more large fermenters according to the present Invention for the production of biogas.

Provided the gas space between the two films of the double film of gas-tight Case with Exhaust gas from the biogas consumer, e.g. a CHP, is flowed through, This exhaust is previously over a cooling device as far as cooled, that it to no damage The gas-tight film may come due to high temperatures (claim 14, 15).

The Exhaust gas cooling device can be unrestricted by The present invention also fermenters are used, the flushed with exhaust before unloading become.

According to one advantageous embodiment of the invention is a Perkolatkonzentriereinrichtung provided, the excess withdrawn from the fermenter percolate excess liquid withdraws and the for the fermentation concentrated important ingredients of percolate (claim 18).

These Percolate concentrator may be independent of the present invention can also be used in other dry fermenters.

The biogas plant according to claim 20 is characterized by an increased security. When biogas fermenters are leaking, the fermenter can form a flammable, explosive biogas / oxygen mixture. Owing to Radio discharge, cigarettes or static electricity can lead to serious explosions. In the biogas plant according to claim 19, the oxygen partial pressure in the respective fermenter is measured or continuously monitored. If the oxygen partial pressure exceeds a certain value in the respective fermenter, this is an indication that a leak has occurred and oxygen is entering. To prevent this dangerous condition, the respective fermenter is shut off from the biogas line when a threshold value for the oxygen partial pressure is exceeded. At the same time cooled exhaust gas, ie essentially CO ₂ , out of the biogas consumer via a Abgasspülleitung in the fermenter with the increased oxygen partial pressure and opened a purge valve in the fermenter, so that the gases contained in the fermenter can escape from the fermenter and finally almost only carbon dioxide remains in the fermenter. If the respective probably leaky fermenter is flooded with carbon dioxide or exhaust gas, it can be opened without risk of explosion and then repaired.

The remaining dependent claims relate to further advantageous embodiments of the invention. Further Details, features and advantages of the invention are shown below Description of preferred embodiments Based on the drawings:

It shows:

1 a block diagram of a biogas plant according to the present invention;

2 a perspective view of a first embodiment of a large fermenter according to the present invention;

3 a sectional view through the embodiment according to 2 ;

4 a perspective view of a plurality of large fermenters according to 2 respectively. 3 ;

5 a 3 corresponding sectional view of a second embodiment of the large fermenter;

6 a 2 corresponding perspective view of a third embodiment of the large fermenter;

7 and 8th a schematic representation of another embodiment of a biogas plant according to the present invention.

1 shows a schematic representation of a biogas plant according to the present invention. The biogas plant includes a large fermenter 2 in which biogas is produced by the dry fermentation process as well as a biogas consumer in the form of a combined heat and power plant (CHP) 4 , That in the large fermenter 2 from biomass 6 biogas produced is via a biogas extraction line 8th the CHP 4 fed. In the CHP 4 By combustion of the biogas, electrical energy is generated and the resulting waste heat is used for heating purposes. With the in the CHP 4 resulting heat energy is the large fermenter 2 over a heating cable 10 heated.

About a percolation trunk 12 is the collected by means of a drainage system not shown percolate from the large fermenter 2 collected and via a Perkolatkonzentriereinrichtung 14 a perch collection tank 16 fed. In the percolate concentrator 14 , which is in principle a filter device, the percolate excess water is withdrawn, so that the important ingredients for fermentation and bacteria present in higher concentration in the thus treated percolate. Percolate collection tank is over a percolate heating pipe 17 also with the CHP 4 connected. As a result, the optimum temperature for the effectiveness of the percolate is made possible. From the perculum collecting tank 16 carries a percolate distribution line 18 to a percolate distributor 19 in the large fermenter 2 to get the perculum from above via the biomass 6 to spray.

2 and 3 show a first embodiment of the large fermenter 2 according to the present invention. The first embodiment is a large fermentor 2 in the form of an elongated extra-long garage. The big fermenter 2 includes a digester 20 to absorb the biomass 6 , This digester 20 includes a gas-tight bottom plate 22 made of concrete on a stable enclosure 24 extends upwards and the biomass 6 receives. In the soil plate 22 are in the manner of a Bodenheitzung heating elements 23 for heating the large fermenter 2 intended. The stable enclosure 24 is a kind of truss structure with a left sidewall 26 , a right sidewall 27 , a rear end wall - not shown - and a front 28 with a loading and unloading 30 passing through a gas-tight flap 32 is lockable. The front 28 consists of a flap frame 34 with the actual loading and unloading 30 that through the flap 32 is gas-tight closable. The flap frame 34 and the rear side, not shown, are preferably made of gas-tight concrete.

The left and the right side wall 26 and 27 the stable enclosure 24 consist of one Plurality of vertical columns 36 in the form of double T-shaped straps with gaps 38 , In the intervals 38 are wall elements 40 inserted, for example in the form of in the double-T-shaped columns 36 engaging wood panels or wooden boards - not shown in detail.

The individual columns 36 the left and right sidewall 26 and 27 be over a roof scaffold 42 connected with each other. The entire digester 20 gets through a shell 44 in the form of a gas-tight film 46 gas-tight. The gas-tight foil 46 is gas-tight with the bottom plate 20 connected and covers the stable enclosure 24 and the roof scaffolding 42 , For gastight sealing of the digester 20 is the gas-tight foil 46 also connected in a gas-tight manner to the rear wall, which is not shown in more detail. Likewise, the gas-tight film 46 gas-tight with the front 28 or more precisely the flap frame 34 connected.

4 shows a majority of large fermentors 2 according to 2 respectively. 3 in an arrangement next to each other. By the arrangement according to 4 In spite of batch operation, continuous gas generation is possible. For this purpose, the individual large fermenter 2 temporally asynchronous with biomass 6 equipped and unloaded.

5 schematically shows a second embodiment of a large fermenter according to the invention 50 in a 3 corresponding sectional view. The essential difference from the first embodiment is that the sheath 44 from a gas-tight double foil 52 with an inner foil 54 and an outer foil 55 with a gas space 56 between the two slides. By incorporation of a gas, eg air, in this gas space 56 between the two slides 54 and 55 is a thermal insulation of the digester 20 reached.

Another difference of the second embodiment over the first embodiment is that the stable enclosure 24 a gas-tight socket 58 which extends from the bottom plates 22 stretches upwards and forms a tub together with the bottom plate. On the upper edge of the gastight base 58 then joins a side wall construction according to the first embodiment. The double foil 52 is therefore not gas-tight with the bottom plate 20 but outside at the top of the gas-tight base 58 with the pedestal 58 connected. The provision of a gas-tight base 58 is advantageous if in addition to the heating elements 23 in the bottom plate 22 even more heating elements 23 needed, then in the gas-tight socket 58 to be ordered.

6 shows a perspective view of a third embodiment of a large fermenter 60 according to the present invention. This third embodiment differs from the second embodiment in that the base 58 is further pulled up from the second embodiment and a left and a right side wall 62 and 63 forms. The gas-tight envelope 44 in the form of a simple foil 46 or in the form of the double foil 52 spans or covers only the roof scaffolding 42 and is gas tight with the top of the left and right side panels 62 and 63 connected. Otherwise, the third embodiment corresponds to the other two embodiments.

operated become the large-scale fermenters according to the invention by means of a single-stage fermentation process in batch mode. "One-stage" means that the various degradation reactions (hydrolysis, acid, and Methane formation) run together in a fermenter. The term "batch operation" indicates a Process principle in which during the fermentation process no additional material supplied or is taken. Once filled in the fermenter biomass remains there until the end of the residence time. In contrast, the work most liquid fermentation processes in continuous operation, there are regularly smaller Quantities of fermentation substrate removed and replaced with fresh material.

The large-scale fermenters according to the invention are tempered via a bottom and, if appropriate, a wall heating. In this way, the entire contact surface fermentation substrate / fermenter can be used for heat transfer. The heating loops are already integrated in the construction of Behäl ter in the concrete walls, so that no disturbing installations inside the container are needed. In addition, via the percolate heating line 17 and a heat exchanger, the supplied percolate to be tempered. This ensures optimal control of the temperature in the fermenter.

The eferungsgemäßen large fermenter or digester are hydraulically operated, gas-tight doors, the flaps 32 locked. The seal is accomplished by means of an inflatable sealing lip. It is attached to the gate and closes when inflated to the valve frame made of concrete gas-tight. Before opening the gate, the air is released from the gasket again. The structure of this seal is described in WO 02/06439.

The Gates open at the top. This prevents a wheel loader from being filled or unloaded accidentally bumping into a goal and this damaged. The sealing lip is fixed in the gate, so it can during the filling process also not be violated.

The large fermenter be with a slight overpressure operated by 20 hPa. This ensures that at no time, also not in case of leakage, an explosive gas-air mixture can arise.

The bottom plate 22 The large fermenters are made of gas-tight concrete. The large fermenters are constructed in an elongated, garage-like manner and can be used with wheel loaders or front loaders. Several fermenters are built in a block next to each other and operated at different times.

There in the dry fermentation plants according to the invention Processed biomasses with a very high dry matter content, results in a compact design of the fermenter and thus the entire Investment. Due to the modular design with several fermenters can be the plant without big Extend effort if capacity is increased at a later date should.

The large fermenter according to the invention are perfect as a supplement for existing composting plants. Organic residues can be used for energy without the processing rail on liquids must be converted. The existing equipment can be used for the operation of the biogas plant be co-used. The dry fermentation can be as additional Treatment step very well in the operation of composting to get integrated.

In dry fermentation, the same gas yields can be achieved as in wet fermentation processes. Of particular note are the low sulfur content and the high methane content in biogas during dry fermentation. According to previous findings, no desulfurization of the biogas is required. The biogas produced in the dry fermentation plant is dried, then gas quality and quantity are measured. The biogas is fed into the combined heat and power plant (CHP) via a gas control system and a gas compressor. The CHP is regulated according to the gas attack, so that no complex external gas storage is necessary. Only the gas space above the fermentation substrate in the fermenters and in the case of double foil the gas space 56 between the two slides 54 and 55 is used as a cache.

With The CHP is converted into biogas into electricity and heat.

Of the Electricity becomes valid Feed-in tariff at the location fed into the power grid. The heat is used to a small extent for heating the system. The majority stands external heat consumers to disposal.

Next There are other possibilities of using biogas in a cogeneration plant: Biogas in natural gas vehicles can be purified to match natural gas quality used or fed directly into the natural gas grid.

The Dry fermentation plants according to the present invention Invention have a Sophisticated security concept. For example, the transition from the methane atmosphere to the air atmosphere accomplished ex-protected before emptying the fermenter. To none Time can be explosive in the fermenter Air-methane mixture arise. While the filling and emptying ensures a suction in the rear of the fermenter for this, that this constantly flows through fresh air is. So is a possible odor nuisance for the driver of the wheel loader locked out. Photocells prevent the gates accidentally closed while a person is in the fermenter room located. additionally is the engineering building positioned so that from the control room of the direct view the gates possible is.

Even though the biogas plants according to the invention due to their robust technology have a high reliability, are additional Arrangements for the case of possible malfunctions. For example, the hydraulically operated gates are secured in this way, that they can not fall off even if the hydraulics do not functioning should be. If the cogeneration unit fails, the biogas can over one Torch to be burned.

The Dry Fermentation Plant will be over computerized System controlled. In the percolate cycle, in the heating and in the CHP operation can different process parameters set for the individual fermentation tanks become. The continuous monitoring the control parameter allows the constant Optimization of the process and thus maximum degradation in the fermenter.

7 schematically shows a further embodiment of the invention with a biogas consumer 4 in the form of a CHP and one or more large fermenters 2 with a gas-tight foil 46 as a shell 44 , That in the CHP 4 Exhaust gas produced by combustion of biogas is supplied via a first exhaust gas line 62 an exhaust gas cooler 64 fed. In the exhaust gas cooler 64 is the hot exhaust gas from the CHP 4 cooled for example by spraying water. The cooled exhaust gas may be via an exhaust gas purge line 66 the big fermenter (s) 2 be supplied. About a first exhaust pipe 68 The gas contained in the fermenter can be blown out. The sinking the fermenter 2 with cooled exhaust gas takes place before unloading the respective fermenter or in the event of the occurrence of a leak, which could lead to an explosive biogas-air mixtures in the respective fermenter. The individual lines 62 . 66 . 68 can be over valves 70 Shut off. The shut-off and opening of these valves is computer-aided. With regard to the specific embodiment of exhaust gas flushing, reference is made to WO 02/06439 A2.

8th shows a variant of the embodiment according to 7 that differs from the embodiment 7 it differs in that one or several large fermenter 20 with double foil 52 as a shell 44 be provided. In addition, a second exhaust pipe opens 72 from the exhaust gas cooler 64 coming into the gas room 56 the double foil 52 and from the gas room 56 out leads a second exhaust pipe 74 , About the second exhaust pipe 72 and the second exhaust pipe 74 can cooled exhaust gas through the gas space 56 the double foil 52 be pumped. In this way the large fermenter can be thermally insulated. The degree of cooling of the exhaust gas can in this case the ambient temperatures and the resistance of the double film 52 be adjusted.

In all embodiments of the invention described above with double foil 52 may instead of gas insulating material, for. B. rock wool in the cavity 56 between inner and outer foil 54 . 55 be introduced. Due to this thermal insulation, the large fermenter is thermally decoupled from the ambient temperatures.

2,50,60

large fermenter

4

biogas consumers

6

biomass

8th

Biogas withdrawal line

10

Heizleutung to the big fermenter

12

Perkulatsammelleitung

14

Perkolatkonzentriereinrichtung

16

Perkulatsammeltank

17

Perkulatheizleitung

18

Perkulatverteilerleitung

19

Perkulatverteiler

20

digesters

22

baseplate

23

Heating element in the bottom plate 22

24

stable encirclement

26.62

left sidewall of the stable enclosure 24

27.63

right side wall of the stable enclosure 24

28

front of the big fermenter

30

loading and discharge opening

32

gas-tight flap

34

flap frame

36

Pillars of stable enclosure

38

Spaces in the stable enclosure

40

wall element the stable enclosure

42

Roof frame of the large fermenter

44

Cover of the large-scale fermenter

46

gas-tight foil

52

double foil

54

inner foil of the double foil 52

55

outer foil of the double foil 52

56

headspace between inner and outer foil

58

base the stable enclosure

62

first exhaust pipe

64

exhaust gas cooler

66

Abgasspülleitung

68

first exhaust pipe

70

valves

72

second exhaust pipe

74

second exhaust pipe

Claims (20)

Large fermenter for the production of biogas from biomass according to the principle of solid methanation, with a digester ( 20 ) for receiving the biomass ( 6 ) comprising: a biogas withdrawal port ( 8th ), a loading and unloading ( 30 ) for loading and unloading the digester ( 20 ) with biomass ( 6 ), wherein the loading and unloading ( 30 ) by means of a flap ( 32 ) gas-tight, a gas-tight bottom plate ( 22 ), and one from the bottom plate ( 22 ) in the height extending stable enclosure ( 24 ), characterized by a shell ( 44 ) in the form of a gas-tight film ( 46 ; 52 ), the digester ( 20 ) gas-tight and on the one hand with the loading and unloading ( 30 ) and outside the stable enclosure ( 24 ) with the bottom plate ( 22 ) and / or the outside of the stable enclosure ( 24 ) and / or the top edge of the stable enclosure ( 24 ) is connected gas-tight. Large fermenter according to claim 1, characterized in that the gas-tight envelope ( 44 ) made of an elastic film ( 46 ; 52 ) consists. Large fermenter according to claim 1 or 2, characterized in that the casing ( 44 ) from a double foil ( 52 ) with a gas space ( 56 ) between the two films ( 54 . 55 ) consists. Large fermenter according to claim 3, characterized in that in the gas space ( 56 ) between the two films ( 54 . 55 ) Gas for thermal insulation of the digester ( 20 ) is stored by the environment. Large fermenter according to claim 3, characterized in that the gas space ( 56 ) is flowed through between the two sheets of exhaust gas, which is produced during the combustion of biogas. Large fermenter according to claim 3, characterized in that in the gas space ( 56 ) between the two films ( 54 . 55 ) Insulating material for thermal insulation of the digester ( 20 ) is stored by the environment. Large fermenter according to one of the preceding claims, characterized in that the loading and unloading opening ( 30 ) partially through the bottom plate ( 22 ) is limited. Large fermenter according to one of the preceding claims, characterized in that the digester ( 20 ) via the loading and unloading opening ( 30 ) is passable. Large fermenter according to one of the preceding claims, characterized in that the loading and unloading opening ( 30 ) of a flap frame ( 34 ) against which the flap ( 32 ) gas-tight and that the envelope ( 44 ) gas-tight with the flap frame ( 34 ) connected is. Large fermenter according to one of the preceding claims, characterized in that above the gas-tight envelope ( 44 ) at least partially a resistant protective cover is provided. Biogas plant for generating thermal, electrical or mechanical energy from biomass, with at least one large fermenter ( 2 ; 50 ; 60 ) for the production of biogas from biomass ( 6 ) according to one of the preceding claims, a biogas consumer ( 4 ) for generating thermal, electrical and / or mechanical energy, a biogas line ( 8th ) for supplying the biogas from the at least one large fermenter ( 2 ; 50 ; 60 ) to the biogas consumer ( 4 ). Biogas plant according to claim 11, characterized in that in the biogas consumer ( 4 ) the biogas is burned. Biogas plant according to claim 12, characterized by an exhaust gas cooler ( 64 ) for cooling the resulting in the combustion of biogas exhaust gas. Biogas plant according to claim 13, characterized in that the resulting exhaust gas via a first and a second exhaust pipe ( 62 . 72 ) into the gas space ( 56 ) between the two films ( 54 . 55 ) of the double foil ( 52 ) and via a second exhaust pipe ( 74 ) from the gas space ( 56 ) of the double foil ( 52 ) is dissipatable. Biogas plant according to claim 14, characterized in that the exhaust gas cooler ( 64 ) between first and second exhaust pipe ( 62 . 72 ) is switched. Biogas plant according to one of the preceding claims 11 to 15, characterized by an exhaust purging device ( 62 . 64 . 66 . 68 . 70 ) for rinsing the large fermenter ( 2 ; 20 ; 60 ) with exhaust gas. Biogas plant according to claim 16, characterized in that the Abgasspüleinrichtung ( 62 . 64 . 66 . 68 . 70 ) an exhaust gas purge line ( 66 ) received from the exhaust gas cooler ( 64 ) to the respective large fermenter ( 2 ; 20 ; 60 ) leads. Biogas plant according to one of the preceding claims 11 to 17, characterized by a percolate concentration device ( 14 ) to concentrate the percolate. Biogas plant for generating thermal, electrical or mechanical energy from biomass, with at least one fermenter for producing biogas from biomass according to the principle of solid methanization, a biogas consumer ( 4 ) for generating thermal, electrical and / or mechanical energy by means of combustion of biogas, a biogas line ( 8th ) for supplying the biogas from the at least one fermenter ( 2 ; 50 ; 60 ) to the biogas consumer ( 4 ), an exhaust purging device for purging the fermenter with exhaust gas, which is produced during the combustion of biogas in the biogas consumer, before discharging the fermenter, and an exhaust gas cooling device for cooling the exhaust gas from the biogas consumer before being fed to the fermenters. Biogas plant according to at least one of the preceding claims 11 to 19, with a Partialdruckmeßeinrichtung for detecting the oxygen partial pressure in the at least one fermenter, a Abgasspülleitung for supplying exhaust gases from the biogas consumer in the at least one fermenter, a valve device for each fermenter for connecting the Abgasspülleitung with the respective fermenter and for connecting the respective fermenter with the environment, and a control device for actuating the valve device and for flooding the respective fermenter, when the oxygen partial pressure in the respective Fermenter exceeds a certain value.