WO2008031600A2

WO2008031600A2 - Apparatus and method for generating energy

Info

Publication number: WO2008031600A2
Application number: PCT/EP2007/007993
Authority: WO
Inventors: Josef Moser; Klaus MÄRTEN
Original assignee: Josef Moser; Maerten Klaus
Priority date: 2006-09-14
Filing date: 2007-09-13
Publication date: 2008-03-20
Also published as: WO2008031600A3; DE102007010600A1

Abstract

The invention comprises an apparatus for generating energy from the fermentation in particular of biological material, wherein energy is obtained from the gas pressure and/or the swelling of the gas produced during the fermentation and/or is used. Furthermore, the invention comprises a method for generating energy in particular from the fermentation of biological material.

Description

Apparatus and method for generating energy

The present invention relates to an apparatus and a method for generating energy, in particular from the fermentation of biological material. Such processes are becoming increasingly important in order to reduce CO ₂ emissions and to ensure a sustainable energy supply, in particular based on renewable raw materials. In particular, manure and / or renewable raw materials are used as biological material.

In known plants while the biological material is fermented in large containers with the addition of water and collected during the fermentation gas is collected. For this purpose, the containers usually have a cap made of a flexible membrane, under which the gas accumulates and can then be discharged. The gas thus generated is then subjected to e.g. burned in diesel engines, which in turn drive generators and thus generate electrical energy

Large agitators in the containers during fermentation must ensure that no layer of suspended matter forms on the surface of the fermenting liquid, which would prevent the gas from escaping from the liquid. This consumes a lot of energy and thus deteriorates the efficiency of the plants.

Even otherwise, the known systems can be improved in terms of their energy yield and their CO ₂ efficiency. Object of the present invention is therefore to provide a device and a method for generating energy in particular from the fermentation of biological material available, which has a high efficiency and optimally uses the resources supplied.

According to the invention this object is achieved by a device according to claim 1 and a method according to claim 16. Advantageous embodiments of the invention are the subject of the dependent claims.

In order to increase the efficiency of the device, the energy from the gas pressure and / or the buoyancy of the gas produced during the fermentation is recovered and / or used in the present invention. While in prior art devices only the chemical energy stored in the gas is utilized by combustion, the present invention utilizes, in addition to the chemical energy, the mechanical energy contained in the gas pressure and / or buoyancy of the gas produced during the fermentation is. In this way, the efficiency of the device according to the invention can be significantly increased compared to the prior art. This energy from the gas pressure and / or the buoyancy of the gas can either be obtained and used, for example, to generate electricity, or already be used in the device, for example for driving device-specific elements.

Advantageously, the device according to the invention in this case has a closed container for receiving a liquid in a lower region and for receiving gas in an upper region, as well as buoyancy bodies, which are arranged movably in the closed container. Depending on the embodiment of the invention, the liquid may comprise water, water with additives or material to be fermented, in particular biological material which is present in the liquid. The buoyancy bodies are advantageously at least partially in the lower, liquid-filled area. In the buoyancy bodies, the gas produced during the fermentation collects and gives the buoyancy bodies an increased buoyancy compared to the liquid so that they move. The kinetic energy of the gas or of the buoyant bodies can then be obtained and / or used in the present invention.

Advantageously, the buoyancy bodies can absorb gas released during the fermentation and release it again. Thus, the buoyancy of the buoyancy body increases by the absorption of the gas, while the buoyancy of the buoyant body by the discharge of the gas decreases again. The buoyancy force acting on the buoyant bodies changes accordingly and moves the buoyancy bodies.

The reception and delivery of the gas takes place advantageously cyclically, so that there is a cyclical movement of the buoyancy body. From such a cyclic movement can then be used in a particularly simple manner for energy.

Advantageously, the buoyancy bodies are at least partially movable into the lower region and can absorb gas formed during fermentation at least in a partial region of the lower region. So while they absorb the gas produced in the fermentation in the lower part, the buoyancy bodies are located below the surface of the liquid and thus obtain by the absorption of the gas the corresponding buoyancy.

Further advantageously, the buoyancy bodies are at least partially movable in the upper region and can deliver absorbed gas there. Thus, the buoyancy of the buoyant body decreases by the release of the gas, making it easier to move back into the lower area with the liquid. The gas is then collected in the upper portion of the closed container and is there ready for further combustion, for example in a diesel engine, as is well known in the art. - A -

Advantageously, the buoyancy bodies are arranged on a support structure through which they are advantageously alternately at least partially movable from the lower region in the upper region and vice versa. In particular, a movement of the carrier structure advantageously results in a cyclical movement of the individual buoyant bodies. For example, while the buoyancy bodies receive gas on one side of the support structure and thereby gain buoyancy which moves the support structure, they advantageously move down the opposite side after releasing the gas and thereby having less lift.

Advantageously, the support structure is used for discharging the mechanical energy generated by the buoyancy bodies. Thus, the mechanical energy can be bundled from the buoyancy of the buoyancy body on the support structure and translated into a uniform movement, from which in turn energy can be obtained.

Advantageously, the device according to the invention comprises means for generating electricity from the movement of the support structure, in particular a generator driven by the support structure. Thus, from the kinetic energy or the buoyancy of the buoyant body electrical energy can be generated, which is available in addition to the energy obtained from the combustion of the gas.

Further advantageously, the support structure according to the invention comprises a revolving conveyor belt, on which the buoyancy bodies are arranged. The buoyancy bodies thus transfer the kinetic energy from the buoyancy of the gas produced during the fermentation to the circulating conveyor belt, which on the other hand transports the buoyancy bodies not filled with gas back down into the liquid.

For this purpose, the circulating conveyor belt advantageously has a vertical plane of movement, ie the buoyant bodies move on one side of the circumferential conveyor belt. move conveyor belts upwards while moving them down the other side.

Alternatively, the support structure can advantageously form a rotor with the buoyancy bodies. Thus, the buoyancy of the buoyancy bodies is converted into a rotational movement, which can be easily picked off on the axis of the rotor.

Advantageously, the axis of the rotor is aligned substantially horizontally. The buoyancy bodies thus essentially move in a circular path, absorbing gas during the upward movement and thus gaining buoyancy, while they are emptied before the downward movement and thus lose their buoyancy. Overall, this gives a rotational movement of the rotor, which can be used, for example, for generating energy or for stirring the liquid in the container.

Further advantageously, the closed container in the upper region of a flexible membrane, so that the volume of the closed container can change. This makes it possible to collect the resulting gas during fermentation in the upper region of the closed container, which can change its volume for this purpose.

The device according to the invention in this case has a particularly advantageous embodiment, in which at least in the lower region of the container, a support structure is arranged, which buoyant body has forming container with variable volume. During operation of the device, the biological material introduced into the fermentation containers undergoes fermentation to release gas, thereby increasing the volume of the fermentation containers. Since the support structure with the fermentation tanks is located substantially below the water surface, the fermentation tanks generate more and more buoyancy, the longer the fermentation takes place. This buoyancy in turn causes the support structure to move, so that in addition to the gas for the production of energy and the mechanical energy from this movement can be used. This increases the energy yield of the invented to the device according to the invention. In addition, by using several fermentation tanks on the support structure of the individual fermentation tanks turn out smaller, so that it can be dispensed with a stirrer, which itself would have a large energy needs.

Advantageously, the fermentation tanks are articulated about a horizontal axis rotatably mounted on the support structure. The fermentation tanks can thus always align horizontally even with a movement of the support structure, so that, for example, an area for receiving the material to be fermented always points downwards, while a usually less stable running area for expanding the volume of the fermentation tank aligns upward.

Advantageously, the fermentation tanks are arranged on a rotor whose axis of rotation is aligned substantially horizontally. The fermentation tanks can be filled by this arrangement with biological material when they are in a position above the axis of rotation of the rotor. During the subsequent downward movement of the fermentation tank around the axis of rotation of the rotor around the fermentation process must first start so that no gas or at least only a small amount of gas is formed in the fermentation tanks during this phase. However, the amount of gas increases steadily while the containers rotate with the rotor about the substantially horizontal axis of rotation of the rotor, so that the fermentation vessels, which move up, contain much more gas and thus have a much larger volume than they opposite container. Due to the buoyancy generated by this, the rotor rotates about its axis of rotation. This rotation can now be used to generate energy. The rotor is extremely slow rotating and generates the energy due to the very high torque. When the containers filled with gas return to a position above the axis of rotation of the rotor, the gas is released and the biological material is exchanged if necessary. Advantageously, the fermentation tanks extend parallel to the axis of rotation of the rotor and are arranged around them. The fermentation tanks are located between two lateral rotor elements in a circular, dense arrangement. The volume of the fermentation tanks can be increased by increasing their cross-section and length, whereby the diameter of the rotor and the length of the axis must change accordingly. The fermentation tanks advantageously have the form of cut-pipe segments, so that they are on the one hand very stable and on the other hand easy and inexpensive to produce. The fermentation tanks are advantageously rotatably mounted on the rotor, so that they rotate automatically during the movement of the rotor by its own weight.

Further advantageously, heating elements for heating the liquid present in the container are arranged in the device according to the invention in the lower region of the closed container. These heating elements thus heat the water surrounding the fermentation tanks, which in turn brings the fermentation tanks to the optimum fermentation temperature. Advantageously, a control is provided which keeps the temperature of the water between 37 and 39.5 ° C. This ensures that the biological material in the fermentation tanks is optimally fermented. Shortly after filling the fermentation tank, they have not yet reached the necessary temperature for fermentation, so that only very little gas is generated at the beginning. This is an advantage, as the fermentation tanks still have very little buoyancy during the downward movement and only come to optimum fermentation temperature over time. The subsequent strong gas evolution thus essentially takes place when the fermentation tanks are already in the upward movement again. The enlarged by the gas volume of the fermentation tank then provides buoyancy, which moves the support structure. Such heating elements are also advantageous regardless of the design of the buoyancy bodies and can e.g. heat biological material directly introduced into the closed container.

Advantageously, the heating elements are operated via the waste heat from the combustion of the gas generated during the fermentation, for example in engines. These engines, usually diesel engines, then power generators that produce electricity. In conventional methods, the waste heat generated during combustion, for example, from the exhaust gases of the engines can be used only insufficient, while it can be used in the inventive device for heating the water in the container and thus for heating the fermentation tank.

Advantageously, the fermentation containers according to the invention have a flexible membrane, through which the volume of the fermentation containers can change. So arises in a fermenter gas from the fermentation of biological material, the flexible membrane expands, thus increasing the volume of the fermentation tank. The flexible membrane must of course be made gas-tight and consists for example of a film of rubber or a suitable plastic. So you can easily provide a fermenter with variable volume. In particular, if the underside of the fermentation container has the shape of a cylinder cut open along its longitudinal axis, the flexible membrane can be stretched over the opening thus created and expands upwards in a semicylinder shape due to the gas produced during the fermentation.

Advantageously, the flexible membrane is mounted in a frame through which the fermentation tank can be opened and sealed again. For discharging the gas or for filling and emptying the fermentation tank with biological material so the frame can be opened with the flexible membrane. In particular, the fermentation tank must be watertight sealable, so that no water penetrates into the fermentation tank located during the fermentation phase. The fermentation tank should also be closed gas-tight, so that the accumulated gas does not escape, but by its buoyancy moves the rotor.

Advantageously, devices for filling and emptying the fermentation tanks are provided in the device according to the invention. About these devices leaves to fill the biological material in the fermentation tank and remove it again after fermentation. These devices are advantageously hose or pipe constructions which communicate with a pumping unit.

Advantageously, the rotor of the device according to the invention is arranged so that the fermentation containers can be moved in the upper region of the closed container above the water level. While the fermentation tanks are therefore most of the time below the water surface, they can also be moved out of the water, advantageously in the area which is provided for receiving gas. Here, the containers can then be much easier emptied and filled than below the water surface.

Advantageously, therefore, the devices for filling and emptying the fermentation tanks are arranged in the upper region of the closed container above the water level. The filling and emptying is done advantageously automatically, since in this area the gas generated by the fermentation is collected and this is therefore not accessible to people.

Advantageously, the fermentation tanks comprise devices for draining the gas generated by the fermentation. About this device, the fermentation tanks can be either completely emptied depending on the design, or these devices can be used to drain during the downward movement of the fermentation tank already forming gas, so as to prevent the buoyancy of the fermentation tank in this phase. Also, these devices can be used to control the rotational movement by the volume of the fermentation tank is set by the discharge of gas.

Further advantageously, the device according to the invention comprises a Vorgärbehälter for pre-fermentation of the biological material, wherein a device for homogenizing and / or reducing the particle size of the biological material is provided in the Vorgärbehälter the leaving liquid, in particular in particular a sieve, a filter or a Zermahlvorrichtung. Even with known devices, the biological material is pre-fermented together with water in a Vogärbe- container, but the particle size of the biological material remains too large or the biological material is poorly mixed with the water, so that then in the subsequent fermentation step biological material are moved by the upwardly moving gas bubbles to the surface of the fermenting liquid. This quickly forms a solid layer of suspended particles which impairs fermentation. The inventive device for homogenizing and / or reducing the particle size of the biological material, this is effectively prevented, so that can be dispensed with in the present invention, the use of a cost and energy intensive agitator for dissolution of the layer. This is particularly useful in the present invention, since agitators can be dispensed with here in the fermenting containers arranged on the rotor and so a particularly energy-saving and compact arrangement is possible.

Advantageously, therefore, the device according to the invention for homogenizing and / or reducing the particle size of the biological material in the Vorgärbehälter leaving liquid is designed so that during the subsequent Vergärschritts no layer of suspended matter on the surface of the liquid forms, which during fermentation forming gas in the liquid. In particular, it is possible to dispense with the energy-intensive use of a rotor for circulating the liquid during the subsequent next fermentation step. For example, the screen is designed accordingly, so that it passes only correspondingly small particles.

The device according to the invention has a further advantageous embodiment, in which the buoyancy bodies form open receptacles for the gas to one side. As a result, the rising in the liquid in the lower region of the closed container gas collects in the recordings of the drive body and thus increases the buoyancy of the buoyancy bodies when the buoyancy bodies are arranged with the opening facing downwards.

Further advantageously, the outer sides of the buoyancy bodies, on the other hand, have a convex shape. Thus, the gas rising in the liquid can not collect in the buoyant body when the convex outside faces down.

Advantageously, the buoyancy bodies are furthermore arranged substantially perpendicular to their direction of movement. This allows the buoyancy bodies to point downwardly, with the convex outer side downwards, while pointing upwards with the opening of the gas intake for downward movement to absorb gas.

Advantageously, for this purpose, the buoyancy bodies are arranged on a support structure such that they can be moved upward by moving the support structure with the convex outer side facing downward and with the convex outer side facing upward. Thus, the support structure is moved overall by the buoyancy of the gas collecting in the buoyant bodies.

Advantageously, the buoyancy bodies are attached to a revolving conveyor belt so that their orientation changes with the direction of movement of the conveyor belt.

Alternatively, the buoyancy bodies are rigidly attached to a rotor and in particular form a paddle wheel.

In a particularly advantageous embodiment, the closed container forms a fermentation container, in particular for receiving the biological material in its lower region. Thus, during the fermentation of the biological material in this ascending gas, it accumulates in the gas which is opened to one side. took the buoyant body and moves it through. The movement of the buoyant bodies can thus simultaneously move the material to be fermented.

The device according to the invention furthermore has a particularly advantageous embodiment, which has a fermentation tank and an agitator arranged in the fermentation tank, wherein the agitator is moved by the gas pressure and / or the buoyancy of the gas produced during the fermentation. Thus, the gas pressure and / or the buoyancy of the gas can be used directly for stirring the present in the fermentation tank to be fermented material, so that a separate drive for the agitator can be omitted. As a result, significant energy savings are possible compared to the prior art.

Advantageously, the buoyancy bodies preferably form the agitator for the fermenting material in interaction with the support structure. The buoyancy then move by their buoyancy the agitator and move so the fermenting material.

In an alternative embodiment, however, the closed container has an outlet element for gas in the lower region. From this outlet element can then flow out of the gas supplied and accumulate in the located in the lower part of the closed container in a liquid buoyancy elements, which are thereby moved.

Advantageously, the outlet element for the gas is arranged below the buoyancy elements in the region in which the receiving side of the buoyancy elements is oriented substantially downwards. Thus, the effluent gas from the outlet can be optimally used to move the buoyancy elements. In contrast, in the region in which the convex outer side of the buoyancy elements points downwards, no outlet for the gas is provided, since the gas flowing out here would uselessly flow up past the outlet elements. Advantageously, the device according to the invention further comprises a fermentation tank in particular for the fermentation of biological material and gas lines for supplying the resulting gas in the fermentation tank to the outlet. Thus, the resulting gas in the fermentation tank can be collected and flows through the resulting gas pressure via the gas line to the outlet in the closed container, from where it rises in the liquid and moves the buoyancy elements.

Advantageously, the closed container is filled in its lower region with a liquid, in particular with water, in which advantageously the specific gravity of the liquid-increasing additives are mixed. It is conceivable, for example, to increase the specific gravity of the liquid by adding sugar solution, salts or metal particles which are soluble in the liquid, which results in greater buoyancy of the gas introduced into the liquid. It is also conceivable to use heavy water.

Furthermore, alternatively instead of the gas produced during the fermentation, other gas such as natural gas or a liquid can be used which is lighter than the liquid located in the lower region of the closed container and does not mix with it. It is conceivable, for example, to use oil which is lighter than water and does not mix with it. This also generates a corresponding buoyancy in the buoyant body, which can be used as mechanical energy.

Furthermore, the present invention comprises an advantageous embodiment, which has a fermentation tank in particular for the fermentation of biological material and gas lines for the discharge of the resulting gas in the fermentation tank, wherein the derived gas drives a mechanical drive by its pressure.

Furthermore, the present invention comprises an advantageous device which has a fermentation tank, in particular for the fermentation of biological material and gas lines for the discharge of the gas formed in the fermentation tank, where the discharged gas conveys, by its pressure, a liquid from a lower-level container to a higher-level container, in particular by the gas driving a pump which pumps the liquid into the higher-level container. This makes it possible to store the mechanical energy contained in the gas, since the liquid in the higher tank has a higher potential energy than that in the lower tank.

Advantageously, when the energy is actually needed, the liquid drains from the higher tank via a downcomer and drives a turbine or generator. Thus, the potential energy of the liquid can be reused, e.g. at peak times.

Advantageously, the pump is arranged in the lower-lying container and this lower-lying container has a dome for receiving the gas. Thus, the gas flowing out of the pump can be collected in the dome and discharged for combustion.

In addition to the devices, the present invention also has a method for generating energy from the fermentation, in particular of biological material, which comprises the following steps:

Filling a fermentation tank, in particular with biological material,

Fermenting the biological material in the fermentation tank so that gas evolves,

Gain and / or benefit of energy from the gas pressure and / or the

Buoyancy of the resulting gas during fermentation.

Obviously, the same advantages result from the inventive method as by the device according to the invention, since the use of the energy contained in the gas pressure and / or the buoyancy of the resulting gas, the efficiency over conventional systems can be significantly increased, which contains only the chemical contained in the gas Energy for example through Exploit burning. On the other hand, in the present invention, both the mechanical energy contained in the gas pressure and / or the buoyancy of the gas and the chemical energy contained in the gas are utilized and / or recovered. In order to facilitate the fermentation of the biological material in the fermentation tanks, the biological material is advantageously inoculated with special bacterial strains.

Advantageously, the resulting during the fermentation gas is collected in buoyancy bodies, which are moved by the buoyancy of the gas. This kinetic energy can then be used or gained.

Advantageously, while the kinetic energy of the buoyancy body is used to drive a generator, which provides electrical energy available.

The present invention further comprises a method for generating energy, in particular with one of the above-described apparatuses, comprising the steps of: filling a fermentation container, in particular with biological material, fermenting the biological material in the fermentation container so that the resulting gas increases the volume of the fermentation container, obtaining mechanical energy from the increase in volume of the fermentation tank, draining the gas from the fermentation tank, and at least partially removing the remaining biological material from the fermentation tank.

Advantageously, the fermentation tank is in the method according to the invention during the Vergärschrittes below a water level, so that the increase in volume generated by the resulting buoyancy mechanical energy, in particular by the fact that the fermentation tanks move a rotor by their buoyancy. This results in a particularly simple way of implementing the increase in volume in mechanical energy. This is advantageously energy obtained from the rotation of the rotor. Thus, in addition to the energy from the generated gas, the energy from the rotation of the rotor is also available.

Advantageously, in the method according to the invention, the biological material filled in the fermentation tank is heated by the water surrounding the fermentation tank. Thus, the fermentation tank is brought by the surrounding water to the optimum temperature for fermentation of about 37 to 39.5 ° C.

Advantageously, the water in the closed container is heated, in particular via the waste heat from the combustion of gas, in particular in an engine. This results in a substantially closed energy cycle, in which the waste heat from the combustion of the gas is used. This results in a particularly good efficiency of the method according to the invention.

The rotational speed is a function of the expiring fermentation process in correlation with the virulence of the fermentation process and the time. The duration of the fermentation process determines the number of rotations and the repetitive rhythm of emptying and refilling of the buoyant bodies. Advantageously, the rotation takes place very slowly, in particular at a speed of less than 5 revolutions per hour. With a rotor diameter of 10m, one can assume in particular of one to two revolutions per hour during the fermentation process, with a very high torque being achieved.

Advantageously, the biological material remains in the fermentation tanks until the main fermentation process is substantially completed. After how many revolutions the biological material is exchanged, determined by the duration of the fermentation process and the rotational speed of the rotor. Advantageously, the entire fermentation process is carried out during a single revolution, so that the biological material can be removed again after one revolution and optionally can be fed to secondary fermentation. This results in a particularly effective fermentation process, since special the newly filled biological material must be heated again over the water and so during the movement of the fermenter down little gas is generated, which would give the fermentation tanks in this phase undesirable buoyancy.

Advantageously, in the method according to the invention by the fermentation gas generated in the fermentation tank and increases its volume, so as to move the rotor by the lift generated. Advantageously, however, gas generated downwardly during the movement of the fermentation tank is discharged immediately. Thus, during the movement of the fermentation tank down its volume does not increase, whereby its buoyancy is not increased.

Alternatively, however, this step can also largely or completely be dispensed with, which simplifies the apparatus design of the fermentation tank. The rotor will still rotate, since it is ensured by the construction according to the invention that the respective opposite fermenter, which moves upward, contains considerably more gas and thus has a larger volume and more buoyancy than the downwardly moving fermentation tank. In addition, the gas generated during the movement of the fermentation tank down to be used to build a certain pressure cushion in the fermentation tank, which compensates for the increasing water pressure in greater depth, so that, for example, only a relatively thin flexible membrane must be used. However, this also results in a poorer energy yield, since the remaining in the downwardly moving fermentation tanks gas inhibits the movement of the rotor.

Further advantageously, the present invention comprises a method, in particular with one or more features of the method described above, comprising the steps of: pre-fermenting the biological material contained in a liquid, homogenizing and / or reducing the particle size of the biological material in the liquid, in particular by sieving , Filtering and / or grinding, and fermenting the resulting liquid. This method has the same advantages as the method described above. Direction, as in the fermentation so no layer of suspended particles on the liquid results, which would have to be removed again by a stirrer. This in turn increases the energy yield considerably and thus enables a very good efficiency. In particular, the CO ₂ efficiency is thus improved considerably.

Advantageously, in this process, the biological material remaining during sieving and / or filtering is returned to the preliminary fermentation. The sieved or filtered out biological material, which either had too large a particle size or was not correspondingly homogenized by the sieves and / or filters, we hereby vorvergoren in the pre-fermentation again, so that the structure of the biological material continues to change, too this is correspondingly distributed homogeneously in the liquid or until the particle size has reduced accordingly or the biological material was changed by the pre-fermentation so that it can be homogenized by the sieves and / or filters according to or reduced in particle size accordingly.

The present invention further comprises an advantageous embodiment of the method according to the invention, in which the gas pressure and / or buoyancy of the rising gas in the fermentation tank is used to drive an agitator arranged in the fermentation tank. This can thus agitate the fermenting material in the fermentation tank, which prevents the formation of a layer of suspended particles on the surface and thus increases the efficiency of the fermentation. By exploiting the gas pressure and / or the buoyancy of the rising gas in the fermentation tank anyway so can be dispensed with an external drive of the agitator, so that there are significant energy savings.

Advantageously, the gas rising in the fermentation tank collects in buoyant bodies arranged in the fermentation vessel and moves it in this way. Furthermore advantageously, the movement of the buoyant bodies further moves the fermenting material in the fermentation container, in particular the biological material. As a result, the buoyancy body, advantageously in conjunction with a support structure, even the stirrer of the fermentation tank. Energy not required for stirring the material contained in the fermentation tank can continue to be used for energy production, for example via a generator.

In an alternative advantageous embodiment, however, the resulting gas in the fermentation tank is collected and passed into another container in which it collects in buoyancy bodies arranged there and moves them so. Thus, the movement of the buoyancy bodies can be used for the production of energy.

Advantageously, the further container is filled in a lower region with a liquid, in particular with water, in which advantageously the specific gravity of the liquid-increasing additives are mixed. This has the advantages already described above in connection with the device.

In an alternative embodiment of the method, the gas produced in the fermentation tank can be collected and conveyed by its pressure a liquid from a lower-lying container in a higher-lying container, in particular by the gas drives a pump which pumps the liquid in the higher-lying container. This results in the same advantages as through the corresponding device.

Further advantageously, the liquid drains from the higher tank via a downcomer and drives a turbine or generator. This also results in the advantages already described in connection with the device.

The present invention will now be explained in more detail with reference to embodiments and drawings. Show

1 shows a first embodiment of the present invention, 2 shows a second embodiment of the present invention,

3 shows an alternative embodiment of the second embodiment,

4 is a schematic diagram of a third embodiment of the present invention;

5 is a more detailed drawing of the third embodiment,

6 is a more detailed drawing of an alternative embodiment of the third embodiment,

Fig. 7 is a schematic diagram of a fourth embodiment of the present invention and

Fig. 8 is a schematic diagram of an alternative embodiment of the fourth embodiment.

The first embodiment shown in Fig. 1 is based on a closed insulated container 1 for receiving tempered water 21 in a lower region 2 and for receiving the escaping gas 23 in an upper region 3. In the lower region 2 are two connected via a longitudinal axis Rotor elements, between which are in a circular arrangement fermenter 12 with variable by gas pressure volume, which are buoyancy bodies. During operation of the device, the fermentation material introduced into the fermentation tank 12 fermented to release gas, which increases the volume of the fermentation tank closed with a membrane 14. Since the fermentation tanks 12 are located on the rotor 10 except for one below the water surface 22, the fermentation tank 12 generate buoyancy; Here, in the fermentation tanks 12th Downstream forming gases discharged via a valve control and rise in the gas dome 5, so that the upward buoyancy can form fully effective energy. In the uppermost vertex above the water surface 22, the gas is discharged by opening the buoyancy body 12 and, if the fermentation process subsides, newly filled with fermentation material. The torque caused by the lift on the axle is then converted into electrical energy via a transmission and a generator. Alternatively, this arrangement could also be realized via a paternoster system, in which the fermentation tanks 12 are arranged on a revolving conveyor belt.

To ensure optimum conditions for the fermentation process in the water tank, the temperature of the water is brought to 39 ° C and maintained. The heating takes place by means of heating elements 7 via the waste heat of the biogas engines of the conventional biogas plant. In order that no suspended layers are formed in the fermentation tanks during fermentation, they are additionally filled with homogenized fermentation material, which provides a higher gas yield.

In detail, this results in the following structure: The first embodiment of the device according to the invention has a closed container 1, which can accommodate water 21 in a lower region 2 and is closed in the upper region 3 with a gas dome for receiving gas 23. For this purpose, the closed container 1 has a solid structure 4, in which the water 21 can be filled. In the upper area, however, the closed container 1 has a common gas dome made of a flexible membrane 5, under which the gas 23 accumulates and thus expands the membrane 5 upwards. In addition, the closed container 1 still has a roof structure 6, which protects the membrane 5 from the weather. For the gas dome, however, other constructions are known. The container 1 is filled up to a water level 22 with water.

In the lower region of the closed container 1, a bearing construction is provided for the rotor 10 acting as the support structure for the buoyant bodies 12. see which consists of struts 8 and bearings 9. The rotor 10 is rotatably mounted on these bearings 9 about a horizontal axis of rotation. The rotor 10 consists of a frame construction, which advantageously comprises radial struts 11. On the rotor 10 acting as a buoyant fermentor 12 are arranged so that the top is always aligned horizontally, with several fermentation tanks 12 are arranged uniformly around the rotation axis in a the size of the closed container 1 corresponding distance. The fermentation tank 12 consist of cylindrical tube halves, which extend parallel to the axis of rotation of the rotor. At the top of the cylinder halves a frame 17 is arranged, which is pivotable and can open or close the fermentation tank 12. On the frame 17, in turn, a flexible membrane 14 is mounted, which bulges upward under the action of the gas generated in the fermentation tank, thus increasing the volume of the fermentation tank. If the fermentation tank is filled with a large amount of gas 24, the overall result is a substantially cylindrical shape for the fermentation tank 12 from the half-cylinder 13 and the then upwardly curved flexible membrane 14. The flexible membranes 14 and 5 are made of one Foil made of rubber, which is thus highly flexible and gas-tight.

The dimensions of the entire system are large, with the fermentation tanks have a length between 20 m and 100 m. This allows large quantities of biological material to be fermented at once.

Furthermore, a device 15 is provided for emptying the fermentation tank 12, which is located in the upper region of the closed container, ie above the water level 22. Likewise, a device 16 for filling the fermentation container with biological material is provided, which is also in the upper region 3 of closed container 1 is located.

Furthermore, heating elements 7 are arranged in the lower region 2 of the closed container 1, which heat the water 21 located in the lower region 2. As a result, the optimum fermentation temperature of 37 to 39.5 ⁰ C can be set. The gas is burned in the inventive device in diesel engines to produce electricity. The heating elements 7 then use the waste heat generated when the gas is burned. The heating elements 7 can thus recycle the waste heat, which in known devices can account for up to 80% of the energy yield.

In the method according to the invention biological material is used, which was already pre-fermented in a pre-Vergärbehälter. The biological material floats in a liquid. In the apparatus according to the invention now sieves or filters are used to homogenize the biological material which is filled in the fermentation tank 12 in the liquid or to reduce the particle size of the biological material accordingly, so that during fermentation in the fermentation tanks 12 does not form a layer on the surface of the fermenting liquid. Alternatively, a crusher can be used for the same purpose.

The correspondingly homogeneously distributed in a liquid biological material or a correspondingly small particle size having biological material is now filled in the inventive method via the device 16 in the fermentation tank 12, while these are located above the water surface 22. For better fermentation, the biological material, which consists for example of manure and / or renewable raw materials such as straw, appropriate bacteria are added. By inoculating the biological material, an optimal fermentation process can be achieved. For filling with biological material of the frame 17 is opened with the flexible membrane 14. Then the fermentation tanks are again closed air and water tight. By the movement of the rotor, in Fig. 1 in the clockwise direction, the fermentation tanks 12 are now moved down into the water and heated by the warmer water. You now reach in the course of the movement down the optimal fermentation temperature, so that the fermentation process starts. The gas 24 produced thereby collects under the flexible membrane 14 and thus increases the volume of the fermentation tank 12th By generating gas in the fermentation tanks is ensured that in the back up moving fermentation tanks 12, which are in the drawing on the left side, considerably more gas is present than on the other side, so that these also a much larger Have volume and thus provide buoyancy. This buoyancy in turn drives the rotor 10. By this rotation, a generator is driven in the embodiment of the invention, which generates electricity. When the gas-filled fermentation tanks reach the area 3 above the water surface 22, they are opened so that the gas can escape from the fermentation tanks and collects in the area 3 below the flexible membrane 5 of the closed container 1. From here, the gas can now be pumped out and used, for example, to generate electricity or for heating. The biological material is now sucked at least partially through the device 15 and refilled new biological material.

The rotational speed of the rotor is a function of the expiring fermentation process, whose virulence determines the gas production, as a function of time. It is either adjusted so that after one revolution of the fermentation process is substantially complete, so that the biological material can be completely removed. For this purpose, depending on the material, a fermentation time and thus also a rotation time for the rotor of about 2 to 48 hours are usually used. Alternatively, the material can be removed only after a few turns, so that a faster rotation is possible. Here then nothing is done as long as the fermentation process is running. Reduces the gas pressure generated and thus the buoyancy force, a refill is made.

Figure 2 shows a second embodiment of the present invention, in which the closed container 1 is constructed exactly as in the first embodiment, but now filled with the biological material to be fermented even up to a surface 22. The heating elements 7 bring the fermentation material in the lower region 2 of the closed container 1 to the optimal fermentation temperature of 39 ⁰ C _{1 to} which the waste heat from the combustion of the gas is used in diesel engines. The gas produced during the fermentation rises through the fermentation material in the lower region 2 of the closed container 1 into the upper region 3 of the closed container 1, in which it accumulates below the flexible membrane 5. From there, as in the first exemplary embodiment, the gas can be supplied to diesel engines for generating electrical energy, which drive a generator.

In the lower region of the closed container 1, as in the first embodiment, a bearing structure for the rotor 10 is provided, which consists of struts 8 and 9 bearings. The rotor 10 is rotatably mounted on these bearings 9 about a horizontal axis of rotation. Uplift elements 12 are arranged on the rotor via struts 11 which, as can be seen from the perspective view at the top in FIG. 2, have on one side a concave inner side which forms a receptacle for the gas rising in the fermentation material, and on the other side Side have a convex outer side 31, at which the rising gas bubbles off. The buoyancy bodies 12 are arranged in a star shape around the axis of rotation of the rotor 10 and all aligned in the same way. The rotor 10 thus receives substantially the shape of a paddle wheel. The buoyancy elements 10 are arranged at a certain distance from the axis of rotation on the struts 11 and consist essentially of a curved material layer, which is connected at their edges with the struts 11.

The gas forming in the biological material during the fermentation process now rises in the lower region 2 of the closed container, collecting in the buoyant bodies 12 shown on the left, while it drips off on the convex outer side of the buoyant bodies 12 shown on the right. This results in a large buoyancy for the buoyancy bodies 12 located on the left side, which causes the rotor 10 to rotate. If the buoyancy vessels 12 reach the upper region 3 of the closed container above the liquid surface 22, the gas can escape from the buoyant bodies 12 into this upper region 3 and collects below the flexible membrane 5. By The rotor 10 again downwardly moving buoyant body 12 have during the downward movement no buoyancy, as the gas rolls off at its convex outer side and thus exerts little force on them. Only when the buoyancy tank 12 again move upwards and thus the receptacle 30 for the gas points down, gas collects again in the buoyancy bodies 12 and again generates buoyancy, which drives the rotor.

Due to the movement of the rotor, the fermentation fermentation is constantly moved, which promotes the outgassing and makes a separate agitator dispensable. Thus, by the arrangement of the rotor 10 shown with the buoyancy bodies 12 can be dispensed with the otherwise necessary energy-consuming separate drive of the agitator. On the contrary, the kinetic energy of the rotor 10, which is not required for stirring, can be taken off the axis and, for example, converted into electrical energy via a generator.

The alternative embodiment shown in Figure 3 of the second embodiment of the present invention differs from the first embodiment only by the modified configuration of the rotor, in particular the buoyancy body 12. These consist in the embodiment shown in Figure 3, as well as from the top in Fig. 3rd shown perspective view, essentially of a curved material layer, which thus forms the receptacle 30 for the gas and the convex outer side 31. The continuous material layer is different than in the first embodiment substantially up to the axis of rotation, while in the embodiment shown in Fig. 2, the buoyancy bodies 12 were only in an outer region of the rotor, wherein they connected via struts 11 with the axis of rotation of the rotor were. However, struts 11 are also provided for stabilizing the buoyancy bodies 12 shown in FIG. 3.

The buoyancy bodies 12 additionally advantageously have side walls, so that gas accumulating in the receptacle 30 can not escape there as well. The in Figs. 4 to 6 illustrated third embodiment of the present invention is based essentially on the same arrangement as the second embodiment, but the closed container 1 is not designed as a fermentation tank, but contains water. Therefore, a separate fermentation tank 35 is provided, at the top of which the resulting gas collects and flows via a gas line 36 to the gas outlet 40, which is arranged in the lower region of the closed container 1. The resulting gas also in the closed fermentation tank 35 presses the gas against the pressure of the above the gas outlet 40 located water column in the closed container 1. The ascending gas collects as in the second embodiment in accordance with designed buoyancy bodies and moves them upwards. The buoyant bodies 12 in turn have a receptacle for the gas which is open towards one side, while their outer side is convexly shaped. The gas outlet 40 is located below the buoyancy body 12 in the region in which the open towards one side receptacle 30 for the gas down, so that as far as possible the entire gas emerging from the outlet 40 is collected in the buoyancy bodies 12 and so provides for the corresponding buoyancy.

In Fig. 4 and Fig. 5, the buoyancy bodies 12 are arranged on a circulating conveyor belt 39, with which they are connected so that the orientation of the buoyancy body 12 also changes with the direction of movement of the belt. Therefore, on the right side shown in the figure, they move down while the convex outside faces downward, while they move up on the left side, while also the convex outside 31 faces upward. So accumulates only on the left side gas in the receptacle 30, which provides for the buoyancy of the buoyancy body 12 and so drives the conveyor belt 39. This runs, as shown in Fig. 5, two rollers 37 and 38. From the axes of rotation, the kinetic energy of the conveyor belt can be removed and transmitted, for example, to a generator, which converts them into electrical energy. In the upper vertex of the movement, the buoyancy bodies 12 exit from the lower region of the closed container 11, ie from the liquid, and discharge the gas accumulated in them into the upper region 3. From there it can now be fed to the gas engine generators.

In the alternative shown in FIG. 6, instead of the conveyor belt 39, a rotor 10 is again used, as already known from the second exemplary embodiment. However, since in the third embodiment, the biological material is fermented in a separate fermentation tank 35, in turn, a gas line 36 and an outlet member 40 is provided in the left lower area below the buoyancy elements 12.

Such operating according to the principles of the third embodiment buoyancy power plant can also be operated with other pressurized media whose specific gravity is lighter than water and which do not form a connection with water. For example, oils such as rapeseed oil can be used here. As a result, the pressure of the pressurized medium can be converted into electrical energy.

Furthermore, in the devices shown in the first and third embodiments, in which the closed container 1 can not be filled with the material to be fermented, but e.g. is filled with water, the efficiency increase by either heavy water is used or the water additives are added, which increase the specific gravity of the water. For example, it is possible to incorporate sugar solution, salt or metal dust into the water. This increases the buoyancy of the gas relative to the water, because there is a greater difference between the specific weights of the gas in the buoyant bodies 12 and the surrounding liquid.

In the fourth exemplary embodiment of the present invention shown in FIG. 7 and FIG. 8, as in the third exemplary embodiment, a separate fermenting vessel 35, such as a fermenting silo, is used, from which the pressurized vessel derived gas from the fermentation via a gas line 36 is derived. In the fourth embodiment, the gas thereby drives a pump 43, which pumps water from a lower arranged first container 41 into a higher arranged second container 42, so that the energy from the pressure of the gas can be stored as potential energy of the water. The pump 43 is arranged directly in the first lower-lying container 41. The gas, after having driven the pump, is drained via discharge 49 to the biogas engine generators. For this purpose, in the alternative shown in FIG. 8, a gas dome 48 is arranged above the pump 41 above the container 41, which extends below the water surface 47.

The pumped via the riser 46 into the upper tank 42 water can now be redirected if necessary via the downpipe 44 to the turbine 45, which drives a generator. For example, at peak loads, the water stored in the upper tank 42 can be used to generate additional energy. The turbine is located in the arrangement shown in Fig. 7 within the lower-lying container, while it is arranged in the arrangement shown in Fig. 8 outside of this container.

The devices according to the third and fourth embodiments can be easily inserted into conventional biogas power plants to increase the efficiency between the already existing fermentation silo 35 and operated with the biogas diesel engines. In this way, the energy from the pressure or the buoyancy of the resulting gas during the fermentation can be used by the existing plant is supplemented by the device according to the embodiments 3 and 4 of the present invention.

Claims

claims

1. A device for generating energy from the fermentation in particular of biological material, wherein energy is obtained from the gas pressure and / or the buoyancy of the resulting gas during the fermentation and / or used.

2. Device according to claim 1, comprising a closed container (1) for receiving a liquid in a lower region (2) and for receiving gas in an upper region (3), and with buoyancy bodies, which are arranged movably in the closed container ,

3. A device according to claim 2, wherein the buoyancy body can absorb gas released during fermentation and release again.

4. The device according to claim 2, wherein the buoyancy bodies are at least partially movable in the lower region and at least in a portion of the lower region in the fermentation emerging gas can absorb and / or at least partially in the upper region are movable and can deliver absorbed gas there ,

5. Apparatus according to claim 2, wherein the buoyancy bodies are arranged on a support structure through which they are advantageously alternately at least partially movable from the lower region (2) in the upper region (3) and vice versa.

6. Apparatus according to claim 5, wherein the support structure for discharging the mechanical energy generated by the buoyancy bodies is used.

7. Apparatus according to claim 5, wherein means for generating electricity from the movement of the support structure are provided, in particular a generator driven by the support structure.

8. The device according to claim 2, wherein the closed container (1) in the upper region (3) comprises a flexible membrane (5), so that the volume of the closed container (1) can change.

9. Apparatus according to claim 5, wherein the support structure comprises a circulating conveyor belt, on which the buoyancy bodies are arranged.

10. The apparatus of claim 9, wherein the circulating conveyor belt has a vertical plane of movement.

11. The device according to claim 5, wherein the support structure with the buoyancy bodies forms a rotor (10).

12. The device according to claim 11, wherein the axis of the rotor (10) is aligned substantially horizontally.

13. Device according to one of claims 2 to 12, wherein at least in the lower region (2) of the container (1) a support structure is arranged, which buoyancy body forming fermenting container (12) having a variable volume.

14. The apparatus of claim 13, wherein the fermentation tanks (12) are pivotally connected about a horizontal axis to the support structure.

15. The apparatus according to claim 13, wherein the fermentation tanks (12) extend parallel to the axis of rotation of a rotor (10) and are arranged around them.

16. Device according to one of the preceding claims, wherein in the lower region (2) of the closed container (10) heating elements (7) for heating the in the container (1) located liquid are arranged.

Apparatus according to claim 16, wherein the heating elements (7) are responsible for the waste heat from the combustion of the gas produced during the fermentation, e.g. be operated in motors.

18. The device according to claim 13, wherein the fermentation tank (12) have a flexible membrane (14) through which the volume of the fermentation tank (12) can change.

19. The apparatus according to claim 18, wherein the flexible membrane (14) is mounted in a frame (17) through which open the fermentation tank (12) and close again close.

20. The apparatus according to claim 13, wherein means (15, 16) for filling and emptying of the fermentation tank (12) are provided.

21. Device according to claim 20, wherein the devices (15, 16) for filling and emptying the fermentation containers (12) are arranged in the upper region (3) of the closed container (1) above the water level (22).

22. The apparatus according to claim 13, wherein the fermentation tanks (12) comprise devices for venting the gas generated by the fermentation.

23. Device according to one of the preceding claims, in particular according to claim 13, with a Vorgärbehälter for pre-fermentation of the biological material, wherein a device for homogenizing and / or reducing the particle size of the biological material is provided in the Vorgärbehälter the leaving liquid, in particular a sieve, a filter or a crusher.

24. Device in particular according to claim 23, wherein the device for homogenizing and / or reducing the particle size of the biological material in the pre-fermentation vessel leaving liquid is designed so that during the subsequent Vergärschritts no layer of suspended matter forms on the surface of this liquid, which would retain the gas forming in the fermentation in the liquid.

25. Device according to one of claims 1 to 12, wherein the buoyancy body to one side open receptacles for the gas.

26. The device according to claim 25, wherein the outer sides of the buoyancy bodies have a convex shape.

27. The device according to claim 24 or 25, wherein the buoyancy body is arranged substantially perpendicular to its direction of movement.

28. The apparatus according to any one of claims 25 to 27, wherein the buoyancy bodies are arranged on a support structure such that they can be moved upward by moving the support structure with the convex outer side facing downward and with the convex outer side facing upward.

29. Device according to one of claims 25 to 28, wherein the buoyancy bodies are attached to a revolving conveyor belt, that changes their orientation with the direction of movement of the conveyor belt.

30. Device according to one of claims 25 to 28, wherein the buoyancy bodies are rigidly attached to a rotor and in particular form a paddle wheel.

31. Device according to one of claims 25 to 30, wherein the closed container (1) forms a fermentation tank, in particular for receiving the biological material in a lower region (2).

32. Device according to one of the preceding claims, with a fermentation tank and with a fermenter arranged in the agitator, wherein the agitator is moved by the gas pressure and / or the buoyancy of the resulting gas during the fermentation.

33. The apparatus according to claim 32, wherein the buoyancy bodies preferably in interaction with the support structure form the agitator for the fermenting material.

34. Device according to one of claims 25 to 30, wherein the closed container (1) in the lower region (2) has a gas outlet element.

35. The apparatus of claim 34, wherein the outlet member for gas is arranged below the buoyancy elements in the region in which the receiving side of the buoyancy elements is oriented substantially downwards.

36. The apparatus of claim 34, further comprising a fermentation tank in particular for the fermentation of biological material and gas lines for supplying the resulting gas in the fermentation tank to the outlet.

37. Apparatus according to claim 13 or 34, wherein the closed container in its lower region filled with a liquid, in particular water of the closed container is liquid and does not mix with it.

39. The apparatus of claim 1, which has a fermentation tank in particular for the fermentation of biological material and gas lines for the discharge of the resulting gas in the fermentation tank, wherein the derived gas drives a mechanical drive by its pressure.

40. Apparatus according to claim 1, which has a fermentation tank, in particular for the fermentation of biological material and gas lines for the discharge of the resulting gas in the fermentation tank, wherein the discharged gas by its pressure conveys a liquid from a lower-lying container in a higher-lying container, in particular by the gas drives a pump which pumps the liquid into the higher tank.

41. The apparatus of claim 40, wherein the liquid drains from the higher tank via a downcomer and drives a turbine or generator.

42. The apparatus of claim 40, wherein the pump is disposed in the lower-lying container and this has a dome for receiving the gas.

43. Process for producing energy from fermentation, in particular of biological material, comprising the steps of:

Filling a fermentation container (12), in particular with biological material,

Fermenting the biological material in a fermentation tank (12) so that gas is evolved,

- Gain and / or benefit of energy from the gas pressure and / or the buoyancy of the resulting gas during the fermentation.

44. The method according to claim 43, wherein the gas produced during the fermentation is collected in buoyant bodies, which are moved by the buoyancy of the gas.

45. The method according to claim 44, wherein the kinetic energy of the buoyancy bodies is used to drive a generator.

46. The method of claim 43, wherein the gas produced during the fermentation of the biological material increases the volume of the fermentation vessel, with the further steps:

- Obtaining mechanical energy from the increase in volume of the fermentation tank (12)

- Draining the gas from the fermentation tank (12)

- At least partial removal of the remaining biological material from the fermentation tank (12).

47. The method according to claim 46, wherein the fermentation tank (12) is below a water level during the fermentation step, so that the increase in volume generates mechanical energy by the resulting buoyancy, in particular in that the fermentation tanks (12) have a rotor (10 ) move.

48. The method of claim 46, wherein the biological material filled in the fermentation tank (12) is heated by the water surrounding the fermentation tank.

49. The method of claim 46, wherein the in a closed container (1) located water is heated, in particular on the waste heat from the combustion of gas, in particular in an engine.

50. The method of claim 46, wherein the biological material remains in the fermentation tanks until the main fermentation process is substantially completed.

51. The method of claim 46, wherein gas generated by the fermentation remains in the fermentation vessel (12) and increases its volume so as to move the rotor (10) by the lift generated, advantageously gas generated downwardly during movement of the fermentation vessel immediately is drained.

52. The method according to claim 46, in particular, with the steps

- Pre-fermentation of the biological material contained in a liquid

Homogenizing and / or reducing the particle size of the biological material in the liquid, in particular by sieving, filtering and / or grinding,

- fermenting the resulting liquid.

53. The method of claim 52, wherein the biological material remaining in the screening and / or filtering is returned to the pre-fermentation.

54. The method according to claim 43, wherein the gas pressure and / or the buoyancy of the rising gas in the fermentation tank is used to drive a arranged in the fermentor agitator.

55. The method according to claim 43, wherein the gas rising in the fermentation tank collects in the fermentation tank arranged buoyant bodies and moves them so.

56. The method according to claim 55, wherein the movement of the buoyant bodies moves the fermentation material in the fermentation container, in particular the biological material.

57. The method according to claim 43, wherein the resulting gas in the fermentation tank is collected and passed into another container in which it collects in buoyancy bodies arranged there and moves them so.

58. The method according to claim 57, wherein the further container is filled in a lower region with a liquid, in particular with water, in which advantageously the specific gravity of water-increasing additives are mixed.

A method according to claim 43, wherein the gas produced in the fermentation vessel is collected and, by its pressure, conveys a liquid from a lower vessel to a higher vessel, in particular by the gas driving a pump which pumps the liquid into the higher vessel ,

60. The method of claim 59, wherein the liquid drains from the higher tank via a downcomer and drives a turbine or generator.