Method and device for producing biogas from a substrate

Abstract

The present invention relates to a method (100) for producing biogas from a substrate, the method (100) comprising: - introducing (101) substrate into a container (201) by means of a feed system (205), - thoroughly mixing (103) the substrate by means of a mixing mechanism (203) arranged in the container (201), - determining (105) at least one state of the substrate by means of at least one contactless sensor (207), with values for at least one variable which have been measured by the at least one contactless sensor (207) being preferably assigned to one state among multiple states by means of a machine learner, and - adjusting (107) the feed system (205) and / or the mixing mechanism (203) according to the determined state of the substrate.

Description

[0001] "Method and device for producing biogas from a substrate"

[0002] Description:

[0003] The presented invention relates to a method and a device for producing biogas from a substrate according to the appended claims.

[0004] In practice, biogas plants for biogas production are widespread and do not have fully automated control, but instead are controlled on demand based on the subjective assessment of an operator. This can significantly impair the efficiency of biogas production.

[0005] Biogas plants are also known that operate semi-automatically. They use physical and / or mechanical sensors, such as pressure sensors, temperature sensors, and float switches, to monitor the status of the biogas plant and adjust the system's functions, such as a mixer, a feed system for adding substances, or similar devices. It is essential that the known sensors are in direct contact with the substrate or with the system components.

[0006] In the context of the present inventions, the term substrate is used collectively for all operating materials which are supplied or can be contained in a container of the biogas plant, such as the fermentation substrate, also referred to as container contents, as well as auxiliary materials such as antifoam agents, iron preparations, enzymes, in particular for influencing the biological activity, process water, liquid manure or other feedstocks to be fermented or the like.

[0007] While existing sensors provide initial insight into the process, it is still necessary for operators to form their own understanding of the process and the substrate and to adjust control parameters based on their subjective experience. Accordingly, operating a biogas plant frequently involves situations that require manual maintenance or manual control. Manual control of a biogas plant can lead to operating errors, resulting in biogas production that is less than optimal in efficiency.

[0008] Furthermore, manual maintenance requires on-site personnel, so that remote control of the biogas plant is not possible continuously and, therefore, is not economically viable.

[0009] EP 2 553 083 B1 describes a method in which process variables are determined as actual values ​​and manipulated variables are adjusted in the event of a control deviation.

[0010] Against this background, one object of the present invention is to provide a reliable method for automatically operating a biogas plant with the greatest possible efficiency. Thus, according to a first aspect of the present invention, a method for producing biogas from a substrate is presented.

[0011] The presented method comprises introducing substrate into a container by means of a feed system, mixing the substrate by means of a mixer arranged in the container, determining at least one state of the substrate by means of at least one contactless sensor and adjusting the feed system and / or the mixer depending on the determined state of the substrate.

[0012] In the context of the present invention, a feed system is understood to mean a system such as a solids feeder, a dosing screw, a pump including a storage container, and / or a conveyor belt, which receives substrate and / or auxiliary materials and feeds them to a plant device, in particular a container, and in particular transports or doses them into the fermenter. Furthermore, the biogas plant can have a number of auxiliary units, such as digestion technology, e.g., an ultrasonic digestion system, extraction technology, thickeners, or the like, for which adjustment depending on the substrate condition can also be provided. If the invention is explained here for a feed system, it can also be provided that, additionally or alternatively, a number of recorded measurements are provided for controlling a number of auxiliary units. In the context of the present invention, a number is understood to mean a singular or plural number of a corresponding feature.

[0013] Containers in the context of the presented invention include all devices for receiving substrate and / or auxiliary materials, for example a storage container, a solids container, a fermenter, a secondary fermenter, pre-pits, fermentation product storage and the like.

[0014] In the context of the present invention, a mixing mechanism is understood to mean a system for mixing a substrate in the container. For this purpose, a mixing mechanism can comprise, for example, a number of stirrers, mixing rollers, dissolving screws, or the like.

[0015] The invention presented is based on the use of at least one non-contact sensor, whereby the sensors can be based on an electromagnetic and / or acoustic mode of operation. Non-contact, in the sense of the invention, refers to a sensor that is not in direct contact with the substrate and / or with system components for which a number of measurements from the list of measurements are to be determined. A key detection level is the surface of the substrate, which has a number of properties that are detected by the at least one non-contact sensor.

[0016] In the context of the present proposal, an electromagnetic sensor is configured to detect electromagnetic radiation, in particular electromagnetic radiation of specific wavelengths in the infrared, visual, and / or ultraviolet ranges of the electromagnetic spectrum. Detection in the radar range can also be provided. An acoustic sensor is configured to detect sound waves, e.g., an ultrasonic sensor. Furthermore, a non-contact sensor can be designed as a passive or active sensor. The passive sensors can, in particular, serve to detect electromagnetic radiation or sound waves that are reflected or emitted by specific detection objects, without the passive sensor itself emitting radiation or sound waves.Alternatively or additionally, an active sensor can be provided that emits radiation or sound waves toward a detection object and detects the reflected radiation or sound waves. Preferably, active electromagnetic sensors from radar and / or lidar technology can be provided.

[0017] Particularly preferably, a passive sensor can be designed as a camera, for example a normal image camera and / or a thermal or infrared image camera.

[0018] By means of the at least one sensor provided according to the invention, at least one state of the substrate is detected. In addition to the state of the substrate, the sensor can also detect a state of the container and / or the feed system and / or the mixing unit.

[0019] In particular, a particular state can be characterized based on physical properties, especially optical properties. For this purpose, a state can be specified using a characteristic value, which is formed, for example, based on one or more optical measurements.

[0020] To create the key figure, a value of one or more measures can be assigned to a respective key figure or a numerical value of the key figure according to a predefined assignment scheme. The assignment scheme can, for example, include a plurality of weighting factors that weight the influence of respective measures on the key figure. Accordingly, such a key figure quantitatively represents a respective state. In particular, the key figure condenses several measures into a single numerical value, so that a complex state comprising many properties can be quickly and easily captured using the key figure.

[0021] Based on values ​​determined by the sensor, in particular the condition of the substrate, the feed system and / or the mixing unit are adjusted so that, for example, a quantity and / or a composition and / or the properties of a fed substrate and / or a recirculate are varied and / or flow properties, in particular a flow rate, a viscosity or the like, of a substrate fermented in the container are biochemically or physically changed.

[0022] Accordingly, the production of biogas using the presented invention is fully automatic and self-regulating.For this purpose, it can be provided that at least one measure from the following list of measures is determined by means of the at least one contactless sensor: surface structure of the substrate, volume of the substrate, temperature of the substrate, temperature distribution in the substrate, surface temperature of the substrate, flow velocity of the substrate, flow pattern of the substrate, substrate viscosity, fiber content in the substrate, substrate quality, substrate type, foam formation in the substrate, yeast part effects, gas content in the substrate, methane gas content in the substrate, gas activity, biological activity, agitator activity, size of floating layers in the substrate, size of sinking layers in the substrate, desulfurization surface size, gas flow rate in the substrate, residual biogas potential in a digestate of the substrate, wherein the at least one measure is determined in the container and / or on the feed system.

[0023] Preferably, at least one measurement from the following list of measurements for a container content, for example in a fermenter, is determined by means of the at least one contactless sensor, particularly preferably by means of a camera: (free) volume of the container (by detecting the fill level), temperature and its distribution, flow velocity, flow pattern, viscosity, fiber content, foam formation, biological activity, gas bubble formation, floating layer formation, inhomogeneities, desulfurization area, in particular in the roof area of ​​a container, expansion behavior due to non-escaped gas, agitator activity.It can also be provided that by means of the at least one contactless sensor, particularly preferably by means of a camera, at least one measurement from the following list of measurements for the substrate is determined before the substrate is fed to a container by means of a feed system: substrate quantity, substrate type and / or substrate composition, substrate quality, in particular for deriving a gas potential, methane content or the like.

[0024] Using the at least one sensor, a plurality of measurements can be determined, which can then be monitored independently of one another. Alternatively or additionally, a plurality of measurements can be at least partially combined, i.e., summarized into a single characteristic value. The mixing mechanism and / or the feed system can be adjusted based on the measurements monitored in this way.

[0025] To adjust the mixing mechanism and / or the feed system, values ​​determined by the sensor can be evaluated directly or, for example, pre-processed using a filter, in particular a mathematical filter and / or an optical filter, in order to obtain particularly meaningful data or to minimize interference variables.

[0026] For example, the orientation, number, running time, intensity, and rotation speed of the mixer can be adjusted. One goal could be to operate the mixer with minimal energy consumption.

[0027] By capturing the substrate itself, especially the

[0028] Container contents, the condition of the substrate can be determined directly by a sensor, for example by analyzing the surface of the substrate for anomalies such as foam formation, particularly using a camera. Since bubbles differ greatly in appearance from the fermentation mass of the substrate, e.g. in their black value, foam formation can be detected and quantified particularly well using an optical sensor. Likewise, an evaluation of gas bubble formation and / or outgassing bubbles based on gas rising in or out of the substrate can be used to derive the gas content and thus the production of biogas. For example, a ratio between the bubble-free surface and the surface covered with bubbles of the substrate can be determined.

[0029] By controlling the mixing unit and / or the feed system based on the determined substrate condition, the substrate condition can be adjusted in a targeted and timely manner, thus avoiding disturbances such as excessive foam formation. For example, the mixing unit and / or the feed system can be activated when bubble formation exceeds a specified threshold or a specified criterion for a particular condition is met.

[0030] It can further be provided that at least one measurement from the following list of measurements is determined by means of the at least one sensor: free volume of the container, occupied volume of the container or fill level, temperature of the container, temperature distribution in the container, surface temperature of the container, container fill level, temperature of the feed system, temperature of the mixing unit. By recording dimensions of the container and / or the feed system and / or the mixing unit, a condition of the substrate can be indirectly deduced. Furthermore, a condition of the container or the feed system or the mixing unit can be deduced, so that, for example, mechanical defects can be detected early and, if necessary, prevented by initiating countermeasures, such as maintenance and / or power limitation or emergency operation.

[0031] It may further be provided that the condition of the substrate is determined continuously or at predetermined time intervals.

[0032] For continuously determining the condition of the substrate, a live image determined by means of the at least one contactless sensor can be evaluated by transmitting the live image as a stream to an evaluation unit, such as a server, in particular a cloud server.

[0033] For continuously or discontinuously determining the condition of the substrate and / or the container and / or the feed system and / or the mixing unit, the at least one contactless sensor can comprise, for example, a webcam that is communicatively connected to the evaluation unit via a communication interface.

[0034] It can further be provided that values ​​for at least one measure determined by the at least one sensor are compared with a target value specified for the at least one measure, and depending on a deviation between the determined values ​​and the target value, the mixing mechanism and / or the feed system are adjusted in such a way that the deviation is minimized.

[0035] By means of a number of target values ​​which are, for example, specified for respective dimensions, in particular stored in a memory of an evaluation unit or control unit, and / or determined, in particular determined during the process of biogas production, target states can be defined to which the substrate and / or the feed system and / or the mixing unit are approximated by a control or regulation of the mixing unit and / or the feed system, so that the presented process can run fully automatically.

[0036] It may further be provided that, in the event that the deviation between the determined values ​​and the target value is greater than a predefined alarm value and / or lasts longer than a predefined alarm duration, a warning message is output on an output unit indicating the deviation.

[0037] In order to report an undesirable condition of the substrate and / or the mixing unit and / or the feeding system only when it is significant, an alarm duration can be specified for which the condition must persist, so that short-term changes in the condition of the substrate and / or the mixing unit and / or the feeding system do not lead to an unnecessary alarm.

[0038] It can further be provided that values ​​determined by the at least one sensor for at least one measure are compared with a target value specified for the at least one measure, and in the event that a deviation between the determined values ​​and the target value is below a specified status threshold, a status message is output on an output unit which reports that the target value has been reached.

[0039] A predefined status threshold can be used to detect and report the successful achievement of a target so that, for example, mixing and / or substrate removal and / or substrate removal from a filled biogas tank can be initiated.

[0040] It can further be provided that values ​​for at least one measurement determined by the at least one sensor, in particular by an optical sensor, for example in the form of a camera, are processed by means of an image recognition algorithm, wherein the image recognition algorithm compares a pattern of a surface structure of the substrate with a predetermined and / or learned pattern and wherein, depending on a deviation between the pattern of the surface structure and the predetermined pattern, the mixing mechanism and / or the feed system are adjusted in such a way that the deviation is minimized.

[0041] To evaluate data, especially images, acquired by a non-contact sensor, an image recognition algorithm can be used to detect patterns. For example, the digital data acquired by the sensor can be segmented and analyzed for predefined patterns or differences between different segments or images.

[0042] By a defined positioning of a non-contact sensor in space, in particular the positioning of a camera, the arrangement of individual features in a measured value field such as a pattern in space, preferably patterns on the substrate surface, can be quantified and a time-dependent change in position in space can be derived.

[0043] It can further be provided that values ​​determined by the at least one sensor for at least one measure are assigned to a state from a plurality of states by means of a machine learner, and in the event that the assigned state deviates from a predetermined target state, a setting predetermined for the assigned state is preferably set for the mixing mechanism and / or the feed system.

[0044] A machine learner, such as a trained artificial neural network, which assigns values ​​to a first class or a second class, or to a first state or a second state, based on a given ground truth, can quickly and reliably detect a deviation from a target state. Preferably, the values ​​quantify the specified metrics describing the substrate. In other words, the machine learner enables the individual recognition of different metrics to identify the condition of the substrate. It can also be provided that constant factors, such as components of a biogas plant, are also recognized in order to avoid misinterpretations when regulating the biogas situation.

[0045] For further training, a computational evaluation of a number of conditions can be provided, depending on which the proposed setting can be made:

[0046] ■ First, the at least one state of the substrate is determined, wherein preferably a number of the dimensions mentioned are determined qualitatively by means of the at least one contactless sensor,

[0047] ■ The at least one contactless sensor determines a plurality of values ​​for a preferably quantitative characterization of the at least one measurement.

[0048] ■ For at least one qualitatively and quantitatively defined measure, it is determined whether the situation is unintentional, whether there is a need for action and what options for action exist.

[0049] ■ If there is a need for action, for example if the condition suggests that biogas production will be too low and / or if, for example, too high energy expenditure is expected for the operation of the biogas plant, the setting can be made to specifically influence the condition of the substrate.

[0050] It can further be provided that, in the event that the assigned state deviates from the specified target state or the assigned state corresponds to an alarm state, a warning message is output on an output unit, indicating the deviation or alarm state. To report the deviation or alarm state, the warning message can be transmitted, for example, to the output unit, which can be a display and / or a memory, so that a user and / or a control function can detect the warning message and initiate appropriate countermeasures.

[0051] It can further be provided that when determining a state of the substrate by means of at least one contactless sensor, preferably by means of at least one electromagnetic, in particular imaging sensor, the substrate and / or the container and / or the feed system are illuminated with a light source that shines in the ultraviolet, visible and / or infrared spectrum.

[0052] By illuminating the substrate and / or the container and / or the delivery system with ultraviolet and / or infrared radiation, properties of the substrate and / or the container and / or the delivery system can be detected that are not detectable by illumination with normal or human-visible light. In particular, substrate components characteristic of a particular state can be detected.

[0053] Preferably, the lighting is switched on as needed, in particular automatically, provided that at least one measurement is to be recorded.

[0054] It may also be provided that when determining a

[0055] To determine the state of the substrate by means of the at least one contactless sensor, the substrate and / or the container and / or the feed system are illuminated with a light source that flashes at a predetermined frequency.

[0056] By illuminating with a light source that flashes at a predetermined frequency, movements or movement patterns in particular can be recorded particularly reliably.

[0057] Accordingly, it can be provided that a large number of data recorded by a contactless sensor are evaluated together over a predetermined period of time. For this purpose, the data can, for example, be integrated over time and preferably serve as the basis for a machine learner. In a particularly preferred further development, a number of status data from a number of biogas plants are linked together and preferably processed using neural networks to detect and evaluate individual states, in particular states of the substrate. If the data from the same and / or other plants allow the conclusion, for example, that the development of an undesirable substrate state is fundamentally associated with the same or very similar previous substrate states, early control is preferably provided by setting so that problems in the production process are detected directly and preferably automatically.Surprisingly, it has been shown that substrate conditions, as a product of different production parameters, are particularly suitable for directly comparing biogas production processes in a large number of containers and regulating them based on this, instead of only recording local parameters of the biogas plant or process control, such as the design of the container, agitator or similar, or process temperature or the like. The presented invention makes a particular contribution to the development and / or maintenance of the microorganisms necessary for biogas production. Very short-term controls may sometimes be necessary, particularly when starting up the plants, for example, if:a plant is commissioned for the first time, when a plant is commissioned after a malfunction or maintenance, and / or when the composition of the substrate changes significantly due to the addition of corresponding substances and / or additives. According to the proposal, unintended substrate conditions can thus be detected even before the actually unintended substrate condition occurs, by preferably dynamically recording and evaluating previously known preliminary stages or substrate conditions, particularly in the form of a dynamic setpoint. This enables particularly efficient plant operation, as the biogas yield is maximized and operating costs are minimized.

[0058] Particularly preferably, therefore, alternatively or additionally, dynamic setpoint generation can be provided by mathematically relating an individual state, preferably by means of machine learning, to other states, for example previous states or states from another container, in order to enable control technology that only intervenes when a detected state is highly likely to have unintentional negative consequences for the production of the biogas. An optical sensor, particularly preferably in the form of a camera, can be used particularly advantageously for the determination. It can further be provided that, depending on the determined state of the substrate, a number of auxiliary units are controlled during adjustment and / or a supply of a number of auxiliary materials is controlled.

[0059] According to a second aspect, the presented invention relates to a device for producing biogas from a substrate.

[0060] The presented device comprises a container, for example for fermenting substrate, wherein the container comprises a mixing unit configured to mix substrate located in the container, at least one contactless sensor and a computing unit, wherein the computing unit is configured to carry out a possible embodiment of the presented method.

[0061] In the context of the invention presented, a computing unit is understood to mean a computer, a processor, a control unit, or any other programmable circuit. In particular, the computing unit can be a cloud server that can, for example, centrally monitor and / or control or regulate a plurality of the devices presented. For this purpose, the cloud server can be communicatively coupled via a communication interface, in particular a wireless interface, to a respective device, in particular to a respective sensor and / or a control unit of the mixing unit and / or the feed system of a respective device. It can be provided that the device further comprises a feed system, wherein at least one contactless sensor is arranged on the feed system, which is configured to detect substrate provided by the feed system and / or a mechanism of the feed system.

[0062] The feed system can comprise, for example, a conveyor belt, a pump, a screw conveyor, an injection system, a vacuum system, and / or a transport system, preferably each with the respective storage containers, for introducing substrate into the container. Accordingly, a sensor configured to detect substrate provided by the feed system and / or a mechanism of the feed system can monitor the status of the feed system and, for example, automatically detect a mechanical misalignment, in particular a blockage or overfilling of the feed system, and issue a corresponding warning message or activate a corresponding emergency operation of the device.

[0063] It can further be provided that an electromagnetic, in particular an imaging sensor, which detects the substrate is arranged in a container.

[0064] It can further be provided that at least one contactless sensor of the device is arranged in a housing which comprises a transparent window and a cleaning system for cleaning the viewing window and / or a number of light sources.

[0065] By using a housing that has a

[0066] By using a cleaning system, such as a wiper and / or a spray water system, contamination of a respective sensor can be automatically prevented or removed, thus maximizing the fully automatic operating time of the device presented and, in particular, enabling remote monitoring or remote control of the device, the container, and / or the biogas plant. The housing can be designed in such a way that it forms an interior space that is essentially separated from the container interior, so that even suspended matter cannot settle on the detection elements of the at least one contactless sensor.

[0067] For example, all components required for the operation of a respective sensor or several sensors, such as power supply, data storage, communication interface and / or lighting elements, can be arranged in the housing in order to protect them from the ambient conditions in the device, in particular in the container, and to minimize the influence of electronic components in particular on biogas generated in the container.

[0068] It can further be provided that the number of light sources comprises a light source that is configured to illuminate in the ultraviolet and / or infrared spectrum and / or comprises a light source that is configured to illuminate in a spectrum visible to humans.

[0069] In particular, by alternating operation of the number of light sources, in which illumination is carried out in the ultraviolet and / or infrared spectrum for a first predetermined period of time and in the spectrum visible to humans for a second predetermined period of time, a multitude of physical properties of an illuminated object, e.g. of the substrate, the feeding system and / or the mixing unit, can be recorded.

[0070] Particularly advantageously, the device can comprise a camera, a radar system, a sonar and / or a lidar system.

[0071] Further features, details, and advantages of the invention will become apparent from the wording of the claims and from the following description of exemplary embodiments with reference to the drawings. They show:

[0072] Fig. 1 shows a possible embodiment of the presented method,

[0073] Fig. 2 shows a possible embodiment of the device presented, and

[0074] Fig. 3 shows a detailed representation of a possible embodiment of a sensor provided according to the invention.

[0075] Fig. 1 shows a method 100 for producing biogas from a substrate.

[0076] The method 100 comprises an introduction step 101 in which an organic substrate, such as corn, hay, liquid manure, dung, food residues, generally renewable raw materials, as well as auxiliary materials, such asIron preparations, enzymes and / or antifoam agents, is introduced into a container 201 by means of a feed system 205, a mixing step 103 in which the substrate is mixed by means of a mixer 203 arranged in the container 201, a determination step 105 in which at least one state of the substrate is determined by means of the at least one contactless sensor 207, for example an optical sensor, in particular during the introduction step 101 and / or during the mixing step 103 and / or between the introduction step 101 and the mixing step 103, and an adjustment step 107 in which the feed system 205 and / or the mixer 203 are adjusted depending on the determined state of the substrate.

[0077] Fig. 2 shows a device 200 for producing biogas from a substrate.

[0078] The device 200 comprises a container 201 for fermenting substrate, wherein the container 201 comprises a mixer 203 configured to mix substrate located in the container 201, a feed system 205, at least one contactless sensor 207, for example an optical sensor in the form of a camera, and a computing unit 209, wherein the computing unit 209 is configured to carry out the method 100 according to Fig. 1.

[0079] Fig. 3 shows a detailed view of a non-contact sensor 207, an optical sensor in this embodiment. The optical sensor is arranged here, for example, in a housing 211, which can be cleaned in the area of ​​a transparent window 219 via a cleaning system 213 comprising a wiper 215 and a spray water system 217.

[0080] Furthermore, a light source 221 and preferably a battery 223, which supplies electrical power to the optical sensor 207, are arranged in the housing 211. The housing 211 is gas-tight and explosion-proof, so that, for example, in the event of an explosion of the battery 223, no spark can ignite the biogas contained in the container 201.

[0081] The invention is not limited to one of the embodiments described above, but can be modified in many ways.

[0082] All features and advantages arising from the claims, the description and the drawings, including design details, spatial arrangements and method steps, can be essential to the invention both individually and in a wide variety of combinations.

[0083] Reference symbol:

[0084] 100 procedures

[0085] 101 Introduction step

[0086] 103 Mixing step

[0087] 105 Investigation step

[0088] 107 Setting step 00 Device 01 Container 03 Mixing unit 05 Feeding system

[0089] 207 contactless sensor

[0090] 209 computing unit

[0091] 211 housing

[0092] 213 Cleaning system

[0093] 215 wipers

[0094] 217 Spray water system

[0095] 219 transparent window

[0096] 221 light source

[0097] 223 Battery

Claims

Claims: 1 . A process (100) for producing biogas from a substrate, the process (100) comprising: - introducing (101) substrate into a container (201) by means of a feed system (205), - mixing (103) the substrate by means of a mixing device (203) arranged in the container (201), - determining (105) at least one state of the substrate by means of at least one contactless sensor (207), wherein values for at least one measure determined by the at least one contactless sensor (207) are assigned to a state from a plurality of states by means of a machine learner, - Adjusting (107) the feed system (205) and / or the mixing device (203) depending on the determined state of the substrate.

2. Method (100) according to claim 1, characterized in that by means of the at least one contactless sensor (207) at least one measure of the following list of measures is determined: surface structure of the substrate, volume of the substrate, temperature of the substrate, temperature distribution in the substrate, surface temperature of the substrate, flow velocity of the substrate, flow pattern of the substrate, substrate viscosity, fiber content in the substrate, substrate quality, substrate type, foam formation in the substrate, yeast dough effect, gas content in the substrate, Methane gas content in the substrate, gas activity, biological activity, agitator activity, size and / or behavior of floating layers in the substrate, size of sinking layers in the substrate, desulfurization surface size, gas flow rate in the substrate, residual biogas potential in a digestate of the substrate, wherein the at least one measure is determined in the container (201) and / or on the feed system (205).

3. Method (100) according to claim 1 or 2, characterized in that by means of the at least one contactless sensor (207) at least one measure of the following list of measures is determined: free volume of the container (201), occupied volume of the container (201), temperature of the container (201), temperature distribution in the container (201), surface temperature of the container (201), container fill level, temperature of the feed system (205), temperature of the mixer (203).

4. Method (100) according to one of the preceding claims, characterized in that the state of the substrate is determined continuously or at predetermined time intervals.

5. Method (100) according to one of the preceding claims, characterized in that that values for at least one measure determined by the at least one contactless sensor (207) are compared with a target value predetermined for the at least one measure, and depending on a deviation between the determined values and the target value, the mixing mechanism (203) and / or the feed system (205) are adjusted such that the deviation is minimized.

6. Method (100) according to claim 5, characterized in that in the event that the deviation between the determined values and the target value is greater than a predetermined alarm value and / or lasts longer than a predetermined alarm duration, a warning message is output on an output unit which reports the deviation.

7. Method (100) according to one of the preceding claims, characterized in that values determined by the at least one contactless sensor (207) for at least one measure are compared with a target value predetermined for the at least one measure, and in the event that a deviation between the determined values and the target value is below a predetermined status threshold, a status message is output on an output unit which reports that the target value has been reached.

8. Method (100) according to one of the preceding Claims, characterized in that values for at least one measure determined by the at least one contactless sensor (207) are processed by means of an image recognition algorithm, wherein the image recognition algorithm compares a pattern of the substrate, preferably a pattern of a surface structure of the substrate, with a predetermined and / or learned pattern and wherein, depending on a deviation between the pattern of the surface structure and the predetermined pattern, the mixing mechanism (203) and / or the feed system (205) are adjusted such that the deviation is minimized.

9. Method (100) according to one of the preceding claims, characterized in that values for at least one measure determined by the at least one contactless sensor (207) are assigned to a state from a plurality of states by means of a machine learner, and in the event that the assigned state deviates from a predetermined target state, a setting predetermined for the assigned state is set for the mixing mechanism (203) and / or the feed system (205).

10. Method (100) according to claim 9, characterized in that that in the event that the assigned state deviates from the specified target state or the assigned state corresponds to an alarm state, a warning message is output on an output unit reporting the deviation or alarm state.

11. Method (100) according to one of the preceding claims, characterized in that when determining (105) a state of the substrate by means of at least one contactless sensor (207), the substrate and / or the container (201), the mixing mechanism (203) and / or the feed system (205) are illuminated with a light source which shines in the ultraviolet, visible and / or infrared spectrum.

12. Method (100) according to one of the preceding claims, characterized in that an optical sensor, preferably a camera, is used for the determination (105).

13. Method (100) according to one of the preceding claims, characterized in that depending on the determined state of the substrate during adjustment (107), a number of auxiliary units are controlled and / or a supply of a number of auxiliary materials is controlled.

14. Device (200) for producing biogas from a substrate, the device (200) comprising: - a container (201) for fermenting substrate, wherein the container (201) comprises a mixing device (203) configured to mix substrate located in the container (201), - at least one contactless sensor (207), - a computing unit (209), wherein the computing unit (209) is configured to carry out a method (100) according to one of claims 1 to 13.

15. Device (200) according to claim 14, characterized in that the device (200) further comprises a feed system (205), wherein at least one contactless sensor (207) is arranged on the feed system (205), which is configured to detect substrate provided by the feed system (205) and / or a mechanism of the feed system (205).

16. Device (200) according to claim 14 or 15, characterized in that at least one contactless sensor (207) of the device (200) is arranged in a housing (211) which comprises a transparent window (219) and a cleaning system (213) for cleaning the viewing window (219) and / or a number of light sources (221).

17. Device (200) according to claim 16, characterized in that the number of light sources (221) comprises a light source configured to illuminate in the ultraviolet and / or infrared spectrum and / or a light source configured to illuminate in a human-visible spectrum.

18. Device (200) according to one of claims 14 to 17, characterized in that the device (200) comprises a number of cameras, radar, sonar and / or lidar.

Images