BRPI0619581A2 - transport arrangement for biomass, large fermenter for biogas generation from biomass, and process for operating a large fermenter - Google Patents

Abstract

TRANSPORT ARRANGEMENT FOR BIOMASS, LARGE FERMENTER FOR THE GENERATION OF BIOGAS FROM BIOMASS, AND PROCESS FOR THE OPERATION OF A LARGE FERMENTER. a transport arrangement (20) for biomass is provided in a fermenter (2) for the generation of biogas, and a large fermenter equipped with the same, in which in the arrangement or fermenter a sufficient flow of biomass through the channel is ensured of transport 18). This is achieved by providing transport mattresses (24-i) on the bottom, side walls and / or the cover or closure of the transport channel. The biomass is moved through the transport channel through the periodic filling and re-emptying of the transport mattresses through a peristaltic movement.

Description

"TRANSPORT ARRANGEMENT FOR BIOMASS, LARGE FERMENDER FOR BIOGAS GENERATION FROM BIOMASS, AND PROCESS FOR OPERATING A LARGE FERMENDER"

description

The invention relates to a transport arrangement for biomass in a biogas generation fermenter according to claim 1 to a large biogas generation fermenter from biomass generation according to claim 7 as well as a as a process for driving such a large fermenter according to claim 11.

So far, biogas technology has focused mainly on the "wet fermentation" of manure and / or bioresidues from the communal area. Installations and devices for generating biogas from biomass according to the wet fermentation process are known, for example, from publications AT 408230 Bl WO 96/12789, DE 3228391 Al, AT 361885 B and DE 19746636 Al.

From DE 3228391 A1 a digester in the form of an elastic hose is known herein in which biomass is transported through the hose by means of an artificially generated peristaltic motion. Peristaltic movement is generated by slings pulled over the hose, by collars on the hose, which is requested with compressed air or by punctures distributed over the length of the hose, which are jointly contracted by means of collars pulled over the hose, which are requested by compressed air, or through punches distributed over the length of the hose, which are sequentially pressed inward sequentially into the hose.

From DE 19746636 A1 a digester in the form of a round silo is known, the digester itself being arranged in the center of the round silo and surrounded by a ring-shaped intermediate region.

Also known from AT 361885 B is a round silo digester comprising a cylindrical outer wall and a cylindrical inner wall, whereby a ring-shaped transport channel is formed.

The liquefied biomass is fed, flows through the transport and is removed again. Additionally, from AT 361885B it is known to provide a cylindrical center wall between the inner wall and the outer wall, whereby an inner and an outer transport channel ring are formed.

Subsequently increasing raw materials with a high content of dry substances (eg corn silage, fodder, whole plants) can only be mixed in this "liquid" process to a limited extent.

The so-called "dry fermentation" allows methanizing run-off biomass from agricultural land from communal bio-residues and preservation areas without transforming the materials into a liquid, pumpable substrate. Biomasses with up to 50% dry matter fraction can be dumped. This dry fermentation process is described, for example, in EP 0 934 998.

In "dry" fermentation, the material to be fermented is not agitated in a liquid phase, such as, for example, in the liquid fermentation of biowaste. Instead, the fermentation substrate introduced into the fermenter is kept permanently moist as the percolate is removed from the fermenter bottom and is again sprayed onto the biomass. Thus, optimal living conditions for the bacteria are reached. In percolate recirculation, the temperature can be further regulated, and there is the possibility of adding additive substances for process optimization.

From WO 02/06439 a bioreactor or fermenter in the form of a ready-made garage is known which is operated according to the principle of dry fermentation in the so-called batch or batch process. In this case, after inoculation with already fermented material, the fermentation substrate is filled with wheel loads in the fermenter. The garage-shaped fermenter is enclosed with a gas-tight gate. The biomass is fermented under air release, in which case no further intimate mixing is performed and no additional material is added. The percolate that seeps from the fermentation material is removed through a drainage chute, stored intermediate in a tank and re-sprayed onto the fermentation substrate for humidification. The fermentation process takes place in the mesophilic temperature range at 34-31 ° C, quenching is by means of bottom and wall heating.

From DE 3341691 A1 a process and apparatus for the anaerobic treatment of high solids organic substances in which biogas also appears is known. In this case, the biomass that flows into a trough is subjected to peristaltic movement and, therefore, transported through the digester. Peristaltic movement is achieved by the fact that the gutter edges, parallel to each other, perform an upward and downward directed movement. At the same time, in up and down movement, pockets are compressed inwards from below for the generation of peristaltic movement in the chute.

The biogas that emerges can be used in a block heating power station for the generation of current and heat. Thus, always enough biogas is available for the block heating power station; In the dry fermentation plant several digesters are temporarily operated. At the end of the residence time, the fermenter chamber is completely emptied and then refilled. The fermented substrate is conducted for post composting so that a conventional compost comparable to organic manure emerges. Such a facility has been successfully operating in Munich for many years.

Known large fermenters generally operate in batch operation, that is, the biogas production of the fermenter has to be stopped for loading and unloading and the biogas-filled fermenter has to be flooded with air. Therefore, a large fermenter operating according to the dry fermentation principle would be desirable, where continuously fresh biomass is fed and used biomass is discharged without interrupting biogas generation. For this purpose it is necessary to provide a transport device in large fermenters whereby biomass is transported from a loading area to a discharge area.

From WO 93/17091 a closed composting device is known in which at the bottom of the container are arranged blowers which can be ordered with compressed air in order to mix the biomass in the container and to transport it through the container of a loading area to a removal area. For biogas generation under air release, this transport process is inadequate due to the sealing problems associated with it (danger of explosion).

From WO 2005/085411 A2 a transport arrangement for biomass in fermenters is known, wherein transport mattresses are arranged at the bottom and side walls of the fermenter, which may be ordered one after the other with a fluid and, With this, a peristaltic motion is generated in order to move the biomass through the fermenter. The conveying power of such conveying mattresses is limited under certain fermenter operating states. Accordingly, the aim of the present invention is, from the known conveying device of WO 2005/085411 A2, to provide a conveying device with better conveying power for biomass in a fermenter for biogas generation.

The solution of this objective is achieved by the features according to claim 1 and claim 7, respectively.

It has been shown in the large fermenters known from WO 2005/085411 A2 that under certain operating conditions so much percolation arises that the biomass fluctuates. With this, the transport mattresses fixed at the bottom no longer attack the biomass and only agitate the percolate.

In addition, biomass is increased through biogas formation, so that biomass collides with the transport channel cover or cover and as a result is prevented from further floating in forward transport. By providing transport mattresses and the transport channel cover or cover and / or the transport channel sidewalls a better transport power is obtained. Thus, sufficient transport power is also ensured when the biomass fluctuates over a percolate accumulation on the bottom or through the impact of the biomass against the roof. The conveying device according to the invention encompasses a plurality of conveying mattresses arranged one after the other in the conveying direction, which are successively filled with fluid and emptied again.

The transport mattresses are, according to a preferred embodiment, additionally arranged and fixed also on the bottom plate of the digester. A peristaltic movement carrying the biomass is generated by upward and downward movement of the transport mattresses across the entire width of the transport channel. The transport mattresses are preferably operated with liquid, in particular hot water, while the transport mattresses on the roof are operated with gas, which does not form an explosive mixture with biogas.

By providing a cover of the transport mattresses, biomass is prevented from being deposited between the transport mattresses and remaining therein.

Additionally, the transport mattresses may also be paired together and arranged facing the side walls. This also achieves and supports a peristaltic movement of biomass through the transport channel.

The transport arrangement according to the present invention may be mounted in conventional bioreactors or fermenters, as they are known, for example, from WO 02/06439 A or WO 2005/085411 A2. Thus, large fermenters according to the invention are provided according to claim 7. In large fermenters according to claim 7, fresh biomass is introduced into a loading area through a gate in the large fermenters which constantly produce biogas. In large fermenters, biomass is transported through the loading area transport arrangement to a discharge area. During the transport of biomass biogas forms and the biomass is "consumed". In the discharge area the "consumed" biomass is removed through a floodgate. Thus, continuous operation is also possible in the generation of biogas according to the principle of methanization of solid substances.

Particularly in large fermenters for the generation of biogas from biomass, sealing problems often appear, particularly in the corners and corners of the container as well as in the openings for loading and unloading. From the wet fermentation region, where the liquefied biomass can be pumped into and out of the digester, therefore, round containers having fewer corners and corners with sealing problems are known. When methanizing solids in large fermenters, these round containers are not used due to the problems of loading and unloading in batch operation. By means of the conveying device according to the present invention and thus continuously possible operation, round containers may also advantageously be used in the "dry fermentation" - claim 9.

The sealing problems of large fermenters are considerably reduced by the round construction mode as the outer wall or inner wall is only required by compression or traction. The usual sealing problems of corners and corners are however reduced. A ring-shaped fermenter container with a ring-shaped transport channel results by construction with a circular ring-shaped inner wall and a circular ring-shaped outer wall surrounding the inner wall. This circular ring-shaped cylinder is subdivided by means of a dividing wall. Biomass is continuously fed into a loading area on one side of the partition wall and continuously drained on the other side of the partition wall at the end of the transport channel into a discharge area. Fresh biomass is fed into the loading area and the biomass consumed in the discharge area is removed through gates, for example by a liquid bath according to the type of a siphon.

According to an advantageous embodiment of the invention, in addition to the lower, upper and / or lateral side carrying mattresses, a thrust mattress is provided in the area of the loading device which can expand in the transporting direction and thus presses biomass further in the transport direction - Claims 8 and 11. Further, it is an object of the present invention to indicate a process for operating a large fermenter in accordance with the present invention.

The solution of this objective is effected by means of the features according to claim 13.

Particularly when using raw materials that subsequently grow in biomass quality, the high liquid content of the biomass may lead to too intense liquefaction of the biomass in the digester. This would seriously damage the transport action of the transport device with transport mattresses. Because only semi-fermented biomass after one passage is removed from the digester and fed to a new passage in the digester, too intense liquefaction is avoided.

According to a preferred embodiment, the percolate removed from the semi-fermented biomass and the filtrate arising from the concentrated microorganisms are fed back into the fermenter. Biogas production is thus improved.

The other subordinate claims refer to advantageous embodiments of the invention.

The following description of exemplary embodiments based on the drawings shows further details, features and advantages of the invention. The figures show:

Figure 1 is a schematic representation of a longitudinally projecting large fermenter whose bottom is covered with transport mattresses;

Figure 2 is a top view of the transport channel of the embodiment according to Figure 1 with a thrust mattress;

Figures 3 to -3c are sectional representations for the illustration of the peristaltic motion generated by the transport mattresses by means of a control by way of example;

Figures 4a-4c are sectional representations for the illustration of the peristaltic movement generated by the transport mattresses by means of an alternative control;

Figure 5 is an alternative embodiment of the transport mattresses;

Fig. 6 is an alternative embodiment wherein the transport mattress is provided with a cover which relays peristaltic motion to the above biomass;

Figure 7 is a schematic representation of a large round builder fermenter according to the present invention;

Figure 8 is a bottom top view of the large round fermenter according to Figure 7 with correspondingly shaped conveying mattresses;

Figure 9 is a cross-sectional representation through the transport channel of the embodiment according to Figure 1 or Figure 7, respectively; and

Figure 10 is an alternative embodiment of a large round fermenter.

Figure 1 shows a large longitudinally designed, parallelepiped fermenter 2 with a rectangular bottom plate 4, a cover wall 5, a right side wall 6, a left side wall 7, a front wall 8 and a rear wall 9. The large fermenter 2 comprises at one end a loading area 10 with a loading device 12 through the front wall 8 - indicated by an arrow - and at the other end a discharge area 14 with a discharge device 16 through the rear wall 9 - also designated by means of an arrow. Between the loading area 10 and the discharge area 14 a transport channel 18 is configured limited by the two side walls 6 and 7. The transport channel 18 is provided with a transport arrangement 20. Fresh biomass 22 is continuously fed into the loading area. by means of loading device 12. Biomass 22 is conveyed to the other end of the large fermenter 2 to discharge area 14. From discharge area 14, biomass 22 is removed by means of discharge device 16. Fresh biomass feed and fermented biomass discharge can be effected through cover 5 or side walls 7 and 8.

The transport arrangement 20 consists of a plurality of transport mattresses 24-1 arranged on the bottom plate 4 in the transport channel 18 directly adjacent to each other. As can be seen from Figure 1, the individual transport mattresses 24-1 extend over the full width of the large fermenter 2 and are in the shape of cylinders halved in the height direction with oval base area. That is, the upper side of the transport mattresses is bulged and not rectilinear as this appears in the representations in figures 1 to 6. The extension of the individual transport mattresses 14i upwards can be periodically increased and decreased by feeding and removing. periodic fluid flow by means of a fluid control device 26. By feeding fluid at and removing fluid from the directly adjacent transport mattresses 24-i, a undulating motion can be produced whereby biomass 22 is discharged. transported from loading area 12 to unloading area 14.

Figure 2 shows a top view on the front of the transport channel 18 of the large fermenter according to figure 1. In the loading area 10 a thrust mattress 25 is disposed on the front wall 8 which, by means of repeated request with fluid, presses the biomass in the direction of transport. Depending on the height of the front wall 8 or the transport channel 18, several thrust mattresses 25 disposed one above the other may be provided.

Continuous transport of biomass 22 via the transport mattresses 24-i is shown schematically in Figures 3a, 3b and 3c for a large fermenter 2 filled with biomass 22 shown schematically. Figures 3a, 3b and 3c show, for the illustration of the peristaltic conveyor movement, respectively, ten transport mattresses 24-1 to 24-10 distributed over the transport channel 18. In the discharge area 14 there are no transport mattresses provided.

Initially according to figure 3a, in the last transport mattress 24-10 in front of the discharge area 14, fluid is pumped against the weight of the biomass 22 resting on the last transport mattress 24-10 and the biomass 22 which it rests on the last transport mattress 24-10 is raised and partially precipitates into the free-discharge region 14. Next, fluid is removed or pumped out of the last transport mattress 24-10. According to figure 3b, fluid is simultaneously pumped into the transport mattress 24-9. After this, the transport mattress 24-8 is pumped while the transport mattress 24-9 is emptied - Fig. 3c - until finally the first transport mattress 24-1 is pumped and again emptied (not shown). Next a wave motion is produced which carries the biomass 22 from the loading area 10 continuously to the unloading area 14. In this control of the individual transport mattress 24-i, the wave motion runs against the transport direction. This control should be particularly appropriate in very high dry substance fraction.

Figures 4a through 4c show an alternative control of the transport mattress 24-i to produce transport of biomass 22 in transport channel 18 from loading area 10 to unloading area 14. In particular biomass 22 with reduced substance fraction dryness and a liquid level on the transport mattresses, where the dry biomass substance floats, an undulating motion in the transport direction is appropriate. This is shown schematically in figures 4a to 4c.

Initially, according to Figure 4a, for the first transport mattress 24-i in the loading region 10, liquid is pumped against the weight of the biomass 22 resting on the first transport mattress 24-1 and the liquid on the First 24-1 transport mattress is kicked out. Then the second transport mattress 24-2 is pumped with liquid - see figure 4a. Then, - see Figure 4b - liquid is emptied from the first transport mattress 24-1 and at the same time the third transport mattress 24-3 is pumped while the second transport mattress 24-2 remains pumped. Then - see Figure 4c - the liquid is emptied from the second transport mattress and the fourth transport mattress is pumped while the third transport mattress remains pumped. In this way a "transport wave" is generated in the transport direction, which transports biomass 22 from loading area 10 to unloading area 14. In this case, the unloading area is not biomass free 22.

Depending on the length of the transport channel, a number of "wave mountains" in the form of fluid-filled transport mattresses moving through the transport channel may be formed. Similarly to the control process according to figures 3 to 3 and c, the direction of the wave motion can also be reversed here.

Figure 5 schematically shows an alternative configuration of the transporting mattresses such that the surface of the transporting mattresses 16-i is inclined in the transported direction in the pumped state. Through this setting, the transport action is increased.

Figure 6 shows another embodiment of the transport arrangement according to the invention which differs from the previously described embodiments in that the biomass 22 does not abut directly on the transport mattresses 24-i, but rather on a carrier mattress cover 28 in the form of a sheet which rests on carrier mattresses 24-i. Thereby, biomass cannot be permanently integrated between adjacent 24-i and 24-i + 1 transport mattresses.

Figure 7 shows a large fermenter 40 in the round construction mode with a circular cylindrical digester 42. The large fermenter 40 comprises a flat bottom plate 44. From the bottom plate 44 extends a cylindrical outer wall circular 46 in height. The circular cylindrical outer wall 46 surrounds a smaller circular cylindrical inner wall 48. The space between outer wall and inner wall is closed by a cover not shown. The bottom plate 44, the outer wall 46, the inner wall 48 and the cover, gas-tightly connected together, form the digester 42. The digester 42 is subdivided within by means of a dividing wall 52. On one side of the dividing wall 52 there is provided a loading area 54 with a loading device 56 passing through the outer wall 46. On the other side of the dividing wall 52 there is provided a discharge area 58 with a discharging device 60 passing through the wall. outer wall 46.

Between loading area 54 and discharge area 58 a ring-shaped transport channel 62 is configured, limited by the inner wall 48 and the outer wall 46. In the transport channel 62 there is provided a transport arrangement 64 of the described on the basis of figures 2 to 5, which comprises a plurality of transport mattresses 66-ie, which are arranged directly adjacent to each other on the bottom plate 54. As can be seen from figure 8, the mattresses of Carriers 66-i are approximately in the form of cut-end cake slices, that is, they are wider in the outer wall region 46 than in the inner wall region 48.

The double arrow 50 designates in Figure 7 a unloading and loading device which is disposed between the loading area 54 and the unloading area 58 through the outer wall 46. Through the unloading and loading device 50 the semi-biomass is removed. fermented 22 from digester 42, dehydrated and again fed back to digester 42. Dehydration may be, for example, by means of a separator. The percolate affecting the separator is filtered and the filtrate formed is returned to the fermenter again. The decomposition rate of biomass 22 is increased by the microorganisms contained in the filtrate and biogas production is thus improved.

The transport arrangement 64 with the transport mattresses 66-i is shown in Figure 8 in a view from above. The conveyor wave motion is generated analogously to the embodiment according to figure 1.

Figure 9 shows a cross-sectional representation through the transport channel 18 or 62 of the embodiments of the invention according to figures 1 and 7, respectively. As can be seen from Fig. 9, upper transport mattresses 67-i are also arranged in cover 5. Upper transport mattresses 67-i are arranged in a mirror image with respect to lower transport mattresses 24-i, 66- Also in the sidewalls 6, 7 or in the outer wall 46 and in the inner wall 48 are also provided lateral carrying mattresses 68-i. In this case, the opposing transport mattresses 68-i are respectively paired together and controlled synchronously. Also the upper and lower carrier mattresses 24-1, 66-1 and 67-1 can be controlled synchronously in pairs. In addition, the control of the transport mattresses 67-i and 68-i is carried out analogously to the control of the lower transport mattresses 24-i and 66-i, respectively. The upper, lower and lateral transport mattresses can be controlled synchronously in one plane, so that peristaltic movement results according to the type of a bowel.

Figure 10 shows an alternate embodiment of a transport arrangement 70 in a representation corresponding to that of figure 8. The transport arrangement 70 also encompasses a plurality of lower transport mattresses 72-i, which are distributed in a channel. internal transport channel 74 and an external transport channel 76. The internal and external transport channel 74, 76 are separated from each other by a central wall 78 disposed concentrically to the inner and outer wall 48, 46. In this case, the number of the transport mattresses 72-i in the outer transport channel ring 76 is greater than in the internal transport channel ring 74. In the exemplary embodiment shown in Figure 10, the number of the transport mattresses 72-i in the transport ring outer transport channel 76 is double the inner transport channel ring 74. Hereby it is taken into account that the transport path in the outer transport channel ring 76 is m It is longer than in the inner transport channel ring 74. The undulating conveyor movement is generated analogously to the embodiments according to figures 1 and 7, respectively. As in the embodiments described above, side and top carrier mattresses may also be provided.

Also in the transport arrangements 64 and 70 there may be provided a transport mattress cover according to figure 6. Also the upper side configuration of the transport mattresses according to figure 5 may be provided. As in the embodiments according to figures 7 and 10 respectively, the transport arrangements 64 and 70 may be arranged, corresponding to the representation in figure 2 in the loading area 54, on the partition wall 52, one or more mattresses. 25 to support the transport of the biomass in the partition wall path 52.

Large fermenters according to the invention for continuous operation are particularly suited for biomass from later increasing raw materials as they are easy to be transported via the conveyor according to the invention. virtue of its homogeneity.

The representations described above are not to scale fidelity, but rather representations of principle.

Reference Number List

2 Large fermenter 4 Bottom plate 5 Cover wall 6 Left side wall 7 Right side wall 8 Front wall 9 Back wall 10 Loading area 12 Loading device 14 Unloading area 16 Unloading device 18 Transport channel 20 Conveyor 22 Biomass 24-i Bottom Conveyor Mattress 25 Thrust Mattress 26 Fluid Control Device 28 Conveyor Mattress Cover 30 Plate Elements 32 Hinge or Swing Connection 40 Large Fermenter in Round Construction Mode 42 Digester 44 Plate Bottom 46 Outer wall 48 Inner wall 52 Partition wall 50 Unloading and additional loading device 54 F Loading area 56 Loading device 58 r Unloading area 60 Unloading device 62 Transport channel 64 Transport arrangement 66-i under carriage 67-i Mattress 68-i Upper Transport Cartridge Side Transport Mattress 70 Transport Arrangement 72-i Lower Transport Mattress 74 Inner Transport Channel Ring 76 External Transport Channel Ring 78 Center Wall

Claims (14)

1. Transport arrangement for biomass (22), in particular from subsequently increasing raw materials, in a fermenter (2; 40) for biogas generation, with a transport channel (18; 62) with opposing side walls (6,7; 46, 48) which are connected to each other via a bottom surface (4) and a cover (5), a plurality of carrying mattresses (14 -i; 66-i; 72-i) distributed through the fluid-filled transport channel (18; 62) which are in contact with the biomass (22) to be transported, and a control device of fluid (26) for the subsequent filling and emptying of transport mattresses (24-i; 25, 66-i; 67-i; 68-i; 72-i) following each other, whereby a movement Peristaltic can be generated, through which the biomass (22) is moved through the transport channel (18; 62), characterized by the fact that the transport mattresses (67-i; 68i) are fixed to the cover (5) and / or at least one of the two side walls (6, 7; 46, 48, 78). Transport arrangement according to claim 1, characterized in that lower transport mattresses (24-i; 66-i; -72-i) are additionally fixed to the bottom surface (4; 44). Transport arrangement according to claim 1 or 2, characterized in that the lower transport mattresses (24-i; 66-i; -72-i) can be filled with liquid, in particular water. Transport arrangement according to one of the preceding claims, characterized in that the transport mattresses (67-i) in the cover (5) can be filled with a gas which together with the biogas does not form a mixture of Explosive gas. Transport arrangement according to one of the preceding claims, characterized in that on the transport mattresses (24-i; 66-i; 72-i) there is provided a transport-mattress cover (28) which transmits to biomass (22) is the peristaltic motion that can be generated by the transport mattresses (24-i; 66-i; 72-i). Transport arrangement according to one of the preceding claims, characterized in that in the transport mattresses on the side walls (6, 7; 46, 48; 78) the transport mattresses (68-i) are paired together. to each other and are arranged opposite each other. 7. Large fermenter for the generation of biogas from biomass according to the principle of methanization of solid substances, with a gas impermeable digester (42) with a bottom plate (4; -44), an area of loading (10; 54) with a loading device (12; 56) passing through the gas impermeable digester (42) for continuously feeding fresh biomass (22) to the digester (42), a discharge area (14; - 58) with a discharge device (16; 58) passing through the gas impermeable digester (42) for the removal of consumed biomass (22) from the digester (42), a transport arrangement (20; 64; 70) as defined in one of the preceding claims for transporting the biomass (22) from the loading area (10; 54) to the discharge area (14, 58), and a biogas removal connection. Large fermenter according to claim -7, characterized in that in the area of the loading device (12; -56) at least one thrust mattress (25) is provided which can be expanded in the transport direction. of biomass, which can be filled with fluid. Large fermenter according to claim -7 or 8, characterized in that the digester (42) comprises: a cylindrical outer wall (46), impervious to gas, in particular circular cylindrical, extending at height from the bottom plate (44), a gas impermeable, in particular circular cylindrical inner wall (48) extending in height from the bottom plate (44), a gas impermeable cover which is connected to the outer and inner wall (46, 48) whereby between the bottom plate (44), outer wall (46), inner wall (48) and digester cover (42) a digester cover (42) is fixed ) with an annular cylindrical shape for receiving the biomass (22), a partition wall (52) extending in height from the bottom plate (44), outer wall (46) and inner wall (48), wherein the loading device (56) on one side of the partition wall (52) runs through the outer wall (46). Large fermenter according to claim 7 or 8, characterized in that between the inner wall (48) and the outer wall (46) a central wall (78) extends from the bottom plate (78). 44) whereby between the inner wall (48) and the central wall (78) a transport channel ring (74) is formed and between the outer wall (46) and the central wall an external transport channel ring (76) is formed. ). Large fermenter according to one of claims 7 to 10, characterized in that the at least one thrust mattress (25) is arranged in the partition wall (52). Large fermenter according to any one of claims 7 to 11, characterized in that a percolate circulation device having a percolate deposit container is disposed within the cylindrical inner wall (48). Process for operating a large fermenter as defined in one of claims 7 to 11, characterized in that it has the following process steps: feeding fresh biomass through the loading device (12); removal of semi-fermented biomass through the discharge device (16; 60; 50); percolate separation from semi-fermented biomass; feedback of the semi-fermented biomass through the loading device (12; 56; 50); and removing the completely fermented biomass through the discharging device (16; 60; 50). Process according to Claim 13, characterized by the following process steps: filtration of the percolate removed from the semi-fermented biomass (22), and re-conduction of the percolate filtrate to the large fermenter.