METHOD FOR DETERMINING A QUANTITY OF CHEMICALLY BONDED CARBON DIOXIDE AND DEVICE FOR DETERMINING THIS QUANTITY

Description

[0001] The invention relates to a method for determining the quantity of chemically bound carbon dioxide within a time interval using a soil-based reagent. The invention also relates to a device for determining this quantity.

[0002] Carbon dioxide emissions lead to higher carbon dioxide concentrations in the atmosphere and thus, due to the greenhouse effect, to a long-term temperature increase. In a moderate scenario, which assumes that carbon dioxide emissions will decrease again from around the middle of the century due to climate protection measures, current model calculations predict a temperature increase of approximately 2.7°C by the end of the century. If, however, a reduction in carbon dioxide emissions is not achieved or only occurs at a significantly later date, considerably higher temperature increases are possible. Such temperature increases, among other problems, will also lead to a significant rise in sea level, which in the long term could be well over one meter.

[0003] Crucial to limiting the temperature increase and avoiding or reducing its negative impacts is reducing the use of fossil fuels and the associated carbon dioxide emissions. However, since achieving a carbon-neutral economy solely through carbon dioxide reduction is very challenging, and since reducing the carbon dioxide already present in the atmosphere through natural processes alone is a very lengthy process, it is advisable to utilize measures that remove and sequester carbon dioxide from the air.

[0004] A promising approach is to improve or enhance natural weathering processes, in which certain types of rock decompose in the presence of carbon dioxide and water, with some of the carbon dioxide involved in the reaction being chemically bound through the formation of carbonates. Since such weathering processes occur at the rock surface, they are usually very slow. However, it is known that by significantly increasing the surface area, for example by first grinding the rock into fine dust, a considerably accelerated weathering process and thus carbon dioxide binding can be achieved. This is also referred to as "enhanced weathering."

[0005] For example, minerals from the olivine group can bind between 0.5 and 1.5 tons of carbon dioxide per ton. Other rock types, such as basalt, dunite, kimberlite, or wollastonite, are also suitable for this purpose. The use of accelerated weathering for carbon dioxide binding is discussed, for example, in publication WO 2020 / 263910 A1.

[0006] Modeling the interaction between carbon dioxide and soils is the subject of BARGRIZAN SIMA ET AL: "Constraining the carbonate system in soils via testing the internal consistency of pH, pCO2 and alkalinity measurements", GEOCHEMICAL TRANSACTIONS, Vol. 21, No. 4, April 22, 2020, XP093015397, DOI: 10.1186 / s12932-020-00069-5.

[0007] Since some of the aforementioned minerals or rock types are permitted fertilizers, in principle very large areas would be available for such accelerated weathering, so that a lot of carbon dioxide could be bound and thus a significant contribution could be made to mitigating climate change.

[0008] To achieve this, however, this land use must be attractive to farmers and landowners. This could be achieved by allowing farmers and landowners to sell emission certificates to offset carbon dioxide emissions resulting from the negative emissions generated by carbon dioxide sequestration. However, this would require quantifying the amount of carbon dioxide sequestered. Since accelerated weathering in open fields can result in significantly different weathering rates than in a laboratory setting, approaches are needed to quantify the actual amount of carbon dioxide sequestered.

[0009] If, as in the aforementioned publication, it is assumed that the bound carbon dioxide is released from the weathered rock, for example through temperature changes, it would be possible to directly measure the amount of bound carbon dioxide. However, this would be very complex, as the rock would have to be collected again from large fields or open areas and extensively processed. Furthermore, the carbon dioxide released from the weathered rock would then have to be stored in another way. If, on the other hand, it is assumed that the weathered rock is used directly for the long-term sequestration of carbon dioxide, such a direct measurement is not possible.

[0010] The invention is therefore based on the objective of determining the quantity of carbon dioxide chemically bound by a reaction agent on the ground, for example by the above-mentioned types of rock or minerals, and in particular without breaking this chemical bond.

[0011] The object is achieved according to the invention by a method for determining a quantity of chemically bound carbon dioxide within a time interval using a soil-side reaction agent, comprising the following steps: Reading in at least one reaction agent parameter relating to the reaction agent, recording a respective measured value for the conductivity of the soil and / or for a respective cation concentration of at least one cation in the soil by means of at least one sensor attached in or to the soil, and determining the amount of bound carbon dioxide as a function of both the reaction agent parameter and the measured value or values.

[0012] Within the scope of the invention, it was recognized that the amount of bound carbon dioxide can be determined with good accuracy if, on the one hand, the properties of the reactant, such as its grain size and / or content of certain minerals, are taken into account by means of the reactant parameter, and on the other hand, at least one measured value is taken into account that relates to the specific weathering conditions on site.

[0013] The reaction agent parameter can, for example, describe the amount of carbon dioxide bound for a specific quantity of reaction agent, or its time derivative, i.e., a binding rate. Such a reaction agent parameter can be determined, for instance, by weathering samples of the reaction agent under laboratory conditions, thereby determining the precise amount of carbon dioxide absorbed or the absorption rate under these conditions. However, it is also possible to input at least one other piece of information as a reaction agent parameter, such as a particle size and / or mineral content of the reaction agent. In this case, characteristic curves or known mathematical relationships, such as those determined by regression, can be used to calculate the amount of carbon dioxide that can be bound per unit of reaction agent, a binding rate, or similar parameters.

[0014] As will be explained in detail later, the amount of carbon dioxide bound by a reactant within a given time interval, or the binding rate, depends on a multitude of factors. However, within the scope of the invention, it was recognized that simply by considering the conductivity of the soil or the cation concentration of at least one cation, a significant improvement in the accuracy of the determined amount of bound carbon dioxide can be achieved compared to considering only the reactant parameter. Depending on the application, it may therefore be sufficient to consider one or more of the aforementioned measured values ​​when determining the bound carbon dioxide. Conversely, in other applications, it may be advantageous to further improve the accuracy of the determination by considering additional information, as will be explained later.

[0015] A significant advantage of the method according to the invention is that, by acquiring sensor-based measurements directly at the reaction or weathering site, a temporal resolution for data acquisition, and thus for determining carbon dioxide sequestration, can be achieved that cannot be achieved with reasonable effort using other approaches to consider local influences on weathering, for example, by taking and analyzing soil samples. For instance, by using wirelessly read sensors, it is easily possible to update the measured values ​​several times a day or even several times an hour, so that the local reaction environment can be represented much more accurately than if, for example, soil samples were only taken weekly or monthly.

[0016] The measured value(s) can be used to record temporal profiles, allowing, in particular, the determination of the amount of carbon dioxide bound per time interval. By calculating the time integral or summation over the measurement intervals, the total amount of carbon dioxide bound in the entire time interval can then be determined.

[0017] Suitable sensors for determining the aforementioned measurements, as well as the additional sensor data that can be considered later, are already known from the field of smart agriculture. For example, the website "https: / / www.dragino.com / products / lora-lorawan-endnode / item / 159-Ise01.html" describes a sensor for monitoring soil moisture, temperature, and conductivity. The website "https: / / teralytic.com / how-it-works.html" reveals measurements of salinity, pH value, and concentrations of specific ions. Adjusting the selectivity for specific ions or cations is possible, for example, by selecting a suitable ion-selective electrode.

[0018] The amount of bound carbon dioxide can be determined based on sensor data from the sensor and / or at least one other sensor, where the sensor data relates to vertical water flow in the soil and / or precipitation amount and / or soil moisture and / or soil alkalinity and / or nutrient content and / or partial pressure of carbon dioxide in the air above the ground. By using all or only some of the aforementioned sensor data, the accuracy of determining the amount of bound carbon dioxide can be further improved.

[0019] The sensor data can be acquired locally by a sensor installed in or near the ground. However, for precipitation measurements, for example, it may be advantageous to use a satellite sensor instead. In this case, the assignment of the sensor data to the area for which the amount of bound carbon dioxide is to be determined can be achieved, for example, by storing the location of the area or, as will be explained later, by determining it based on GPS data. The partial pressure of carbon dioxide can be determined particularly close to the ground, for example, by using a measuring module, which is partially embedded in the ground, to incorporate a suitable sensor in the section of the module that protrudes above ground level.

[0020] Vertical water flow in soil and / or precipitation amounts can be measured, in particular, using a lysimeter. For example, a lysimeter based on vertically spaced moisture sensors can be used, making low-maintenance operation and electronic data readout particularly easy.

[0021] Directly measuring alkalinity can be relatively complex. For example, a soil sample could be automatically taken and analyzed. Therefore, it can be advantageous to determine or estimate alkalinity based on additional sensor data or measurements, such as by comparing an expected pH change based on other parameters with an actual pH change. To this end, it can be useful to provide additional data from external sources, describing, for example, the type of vegetation, specific soil properties, or similar characteristics. This additional data can either be transmitted to the sensor(s) or the calculation can be performed on a server or other data processing device located away from the sensor.

[0022] Sensor data relating to the nutrient content of the soil may particularly concern the concentration of nitrogen, potassium, or phosphorus compounds or ions in the soil.

[0023] The amount of bound carbon dioxide can be determined based on sensor data from the sensor and / or the additional sensor and / or at least one further sensor, whereby the sensor data relates to a pH value and / or a temperature of the soil. The pH value and temperature of the soil can also influence the binding of carbon dioxide, and the formation of carbonic acid during the binding process can be detected based on the pH value.

[0024] In particular, several or even all of the various sensor data mentioned above can be taken into account when determining the amount of bound carbon dioxide. By evaluating a broad spectrum of measured parameters that influence and / or are influenced by weathering, a high degree of accuracy can be achieved in determining the amount of bound carbon dioxide. Due to the sensor data acquisition, a high temporal resolution can be achieved, and when using multiple spaced sensors, a high spatial resolution can also be obtained.

[0025] The reaction agent parameter can specify a base value for the amount of bound carbon dioxide or for the time derivative of this amount, which is multiplied by at least one correction factor during the calculation. At least one of these correction factors depends on the measured value, or at least one of the measured values, and / or on at least parts of the sensor data. It has been found that corrections due to different influences are particularly easy to separate using this type of calculation. At least one of the correction factors can depend on at least one of the aforementioned quantities as well as on at least one of the preliminary information explained later. Individual correction factors can also depend exclusively on at least one of the preliminary information.

[0026] As an example, a weathering rate R real at time t, which may correspond to or be proportional to the time derivative of the amount of bound carbon dioxide, can be calculated as the product of the basic value R reason for this time derivative and 6 correction factors: R real t = R Grund t * f Leifähigkeit t * f Boden t * f Umwelt t * f Flüssigkeit t * f pH t * f alk t

[0027] The base value RGrund can be determined under laboratory conditions, as explained above. The various correction factors f can each depend on at least one of the measured values ​​and / or sensor data and / or preliminary information, which will be explained later. To determine the respective correction factor f from the respective input variables, test series can be conducted, for example, to establish such a relationship using a lookup table, regression analysis, or machine learning.

[0028] The correction factor f conductivity can, for example, depend solely on the measured conductivity of the soil. The correction factor f soil can relate to other soil properties and, in particular, depend on at least one measured value for the cation concentration and / or on preliminary information relating to soil porosity and / or soil type and / or fungi and / or bacteria present in the soil and / or vegetation. The correction factor f environment can relate to environmental influences and, in particular, depend on temperature and / or precipitation measured as part of the sensor data or on preliminary information relating to these quantities. The correction factor f pH is determined from a soil pH value, which is recorded primarily as sensor data, and the correction factor f alkalinity is determined from alkalinity, which can be recorded as sensor data or provided as preliminary information.The use of the six correction factors mentioned above is just one possible example of an advantageous combination of correction factors. It is also possible, for example, to disregard one or more of the mentioned correction factors or to use additional correction factors.

[0029] The individual correction factors f typically fluctuate around the value 1 and each reflects a certain increase or decrease in the time derivative of the amount of bound carbon dioxide due to the influencing factors on which they depend. While it is not necessary to use all of the aforementioned correction factors f, considering a large number of influencing factors can significantly improve the overall accuracy of the determined weathering rate R.

[0030] The amount of carbon dioxide chemically bound within a time interval by means of a soil-side reagent can be analytically determined by integrating the weathering rate R over time. However, since the various influencing factors, especially the measured value(s) and the sensor data, are typically recorded discretely over time anyway, such an integral can be approximated by summing over the measurement intervals. It is not necessary to use the same measurement interval for all influencing factors.

[0031] The cation concentration can be determined as the concentration of sodium ions and / or calcium ions and / or magnesium ions. In particular, the cation concentration can be determined as the concentration of the cation(s) that were part of the reactant before weathering or the reaction.

[0032] The weathering reaction is explained below using the example of the weathering of forsterite (Mg₂SiO₄). The following reaction equation can be given for this: Mg₂SiO₄ + 4CO₂ + 4H₂O ↔ 2Mg²⁺ + 4HCO₃⁻ ↔ 2MgCO₃ + SiO₂ + 2CO₂ + 4H₂O

[0033] As can be seen from this reaction equation, during the weathering of forsterite in the presence of carbon dioxide and water, half of the carbon dioxide molecules used are bound as magnesium carbonate. Dissolved magnesium cations are present in an intermediate step of this reaction, so the concentration of these cations correlates with the weathering rate.

[0034] The respective measured value and / or the sensor data and / or at least an intermediate result derived from the measured value and / or the sensor data can be wirelessly transmitted from a measurement position, where the respective sensor(s) is / are located, to a processing unit that determines the amount of bound carbon dioxide. Communication can be implemented, for example, via a mobile communication protocol, e.g., 3G, LTE, 5G, Edge, etc., or via a wide area network, in particular a long-range wide area network (LoRaWAN, e.g., Zero-G).

[0035] Using a processing unit located away from the respective measurement position is particularly advantageous when determining the amount of bound carbon dioxide and collecting and jointly evaluating measured values ​​or sensor data from several different measurement positions, for example, from various agricultural fields, each equipped with its own sensors. This can be useful, for instance, to achieve not only high temporal resolution but also high spatial resolution for the measured values ​​or sensor data, thus further improving the accuracy of the determination.

[0036] The processing unit can be, for example, a server, a cloud-based solution, or even a desktop computer. Using a separate processing unit can also be advantageous if, for instance, preliminary information is to be used to determine the amount of carbon dioxide bound. This information may be stored in the processing unit or obtained from external sources, such as a laboratory analyzing soil samples, e.g., via the internet.

[0037] The processing facility itself, or another facility supplied with information regarding the amount of carbon dioxide captured, can provide this information to users via a web interface, an app, or similar means. This allows for short delays of significantly less than one hour, particularly less than 10 minutes, between the acquisition of the measured values ​​or sensor data and the provision of an updated amount of captured carbon dioxide, thus enabling just-in-time information to be provided to, for example, farmers providing land or similar process participants.

[0038] In the method according to the invention, the measured value(s) and / or at least parts of the sensor data can be acquired several times a day or several times per hour, and the amount of bound carbon dioxide can be determined based on this. High temporal resolution of the measurement and determination ensures high accuracy, which can also detect and account for short-term changes in carbon dioxide uptake, for example, due to brief periods of rainfall. Such high temporal resolution of the measurement data acquisition and evaluation would not be achievable with reasonable effort, for example, if the amount of bound carbon dioxide were determined solely based on soil samples.

[0039] The measured value, or at least one of the measured values ​​and / or the sensor data, can be acquired at multiple measurement positions by a single sensor, with the measurement positions being spaced less than 500 m or less than 200 m apart. For example, a separate sensor or a separate measurement module comprising multiple sensors can be provided for each field, at least for some of the measured values ​​or sensor data. This allows, for instance, separate data acquisition for each half hectare or per hectare. This is not only advantageous for enabling individual billing even for relatively small fields belonging to different farmers or in similar situations, but it also improves overall quantity recording, as local differences regarding cropping, soil conditions, etc., can be taken into account with good accuracy.

[0040] A soil sample can be taken from the soil, particularly in the area of ​​the respective measurement position where the sensor(s) is / are located, before the respective measurement value and / or sensor data is recorded. This sample is then analyzed, particularly at a distance from the sampling location in a laboratory, to determine preliminary information such as alkalinity, porosity, soil type, and / or the presence of fungi and / or bacteria in the soil. The amount of bound carbon dioxide is then determined based on this preliminary information. For example, the soil type can be determined to indicate whether it is sandy or loamy, or similar characteristics.

[0041] As previously explained, taking soil samples is typically not possible with the same frequency as measuring parameters or sensor data. However, soil samples and, for example, laboratory analyses can be used to determine these parameters more precisely, or even in the first place, and thus allow them to be taken into account. It can therefore be advantageous to take soil samples at relatively long intervals of, for example, several weeks or even months, to obtain information about the aforementioned, relatively slowly changing soil parameters, while more rapidly changing parameters can be detected and considered using sensors.

[0042] A respective preliminary information, which in particular relates to alkalinity and / or porosity and / or soil type and / or fungi and / or bacteria present in the soil and / or vegetation and / or the weather, and / or the respective preliminary information determined on the basis of the soil sample, can be provided separately for several areas, wherein in a measurement area that includes the and / or the further sensor, an additional positioning device is used which provides position information relating to the respective measurement area, wherein, on the basis of the position information, the preliminary information assigned to the measurement area is selected, according to which, depending on this and the at least one measured value recorded in the measurement area and / or at least parts of the sensor data recorded in the measurement area, the amount of bound carbon dioxide or an intermediate result,The amount of bound carbon dioxide depends on this factor. As an intermediate result, a time derivative or a change in the amount over time can be determined, from which the amount can be calculated by integration or discrete-time summation.

[0043] The preliminary information can be determined through a soil sample or entered manually, for example, if it concerns a planting. Additionally or alternatively, preliminary information can be obtained via satellite, an aircraft-based sensor, or similar methods.

[0044] All sensors for a specific measuring range, or at least parts of these sensors, can be integrated into a single measuring station along with the positioning device. However, it is also possible for several distributed sensors to communicate with a central station for the respective measuring area, for example via a wireless local area network. This central station must either have its own positioning device or communicate with it.

[0045] If the quantity or intermediate result is determined for several measurement areas, the quantities or intermediate results can be added together, or a weighted summation can be performed to take into account, for example, different sizes of the measurement areas.

[0046] It can be useful to determine various intermediate results, such as different correction factors explained above, for areas of varying sizes. For example, precipitation amounts or temperatures can be recorded for relatively large measurement areas, and soil conductivity, cation concentration, nutrient concentration, or similar parameters, along with the resulting correction factors, can be determined separately as intermediate results for several sub-areas within this larger measurement area.

[0047] Determining the positional information also makes it possible to calculate the amount of carbon dioxide sequestered for several separate measurement areas, e.g., for different fields, using a single processing unit. Optionally, separate billing or certification of carbon dioxide sequestration for individual measurement areas or subgroups of measurement areas may still be possible.

[0048] The positioning device can, for example, perform satellite-based positioning, e.g., using GPS. Alternatively, instead of using a positioning device, it would also be possible to provide the measured values ​​or sensor data from sensors within a measurement area to the processing unit via a communication device, thereby also recording an identifier for the communication device, such as a subscriber number in a wireless network. The assignment of the measured values ​​or sensor data to specific measurement areas can then be carried out based on this identifier and a previously defined assignment of identifiers to the measurement areas.However, this would require manually assigning the individual communication devices to the individual measurement areas, resulting in a higher workload and a certain risk of error, for example through an accidental swapping of communication devices or measurement modules.

[0049] In addition to the method according to the invention, the invention relates to a device for determining a quantity of chemically bound carbon dioxide within a time interval using a soil-side reaction agent, comprising at least one sensor for recording measured values ​​for the conductivity of the soil and / or for a respective cation concentration of at least one cation in the soil and a processing device, wherein the device is configured to carry out the method according to the invention.

[0050] A standard data processing device, such as a server, a workstation, a cloud-based data processing device, a smartphone, a tablet, or similar, can be used as the processing unit. This device receives the measurement data, and in particular the sensor data described above, from the sensor(s) and stores the reaction agent parameter and, optionally, the preliminary information, or retrieves it from another device, for example, via the internet. The determination of the amount of bound carbon dioxide and the data acquisition from the sensor, the optionally used positioning devices, etc., can be implemented, for example, by a program executed by the data processing device.

[0051] The device can comprise at least one measuring module, which includes a housing designed for insertion into the ground, at least one sensor, a communication device for wirelessly transmitting measured values ​​and / or sensor data acquired by the sensor and / or an intermediate result determined from the measured value and / or sensor data to the processing device, and at least one power supply device for powering the communication device and the sensor. The measuring module can be rod- or stake-shaped, at least in one section, to facilitate easy insertion into the ground. It can, for example, be inserted, screwed, or hammered into the ground. When inserted into the ground, a section of the measuring module 15 to 100 cm long, and in particular a section 30 to 50 cm long, can be located within the soil.At least parts of the sensors can be located at different heights of the measuring module, for example to enable the determination of a vertical liquid flow by means of vertically spaced moisture sensors.

[0052] The measuring module can include a data processing unit, for example, a CPU or microcontroller with associated memory. This unit can control the communication device, read the sensor(s), optionally determine the intermediate result described above, or perform similar tasks. The housing can be water- and / or dirt-resistant or include a compartment for at least some of the electronics, such as the communication device, the processing unit, and / or the power supply unit, which are also water- and / or dirt-resistant. In particular, water ingress from the ground should be prevented by appropriate housing sealing. The housing should protect the electronic components from all foreseeable weather and seasonal influences. Preferably, the housing is sufficiently robust to be, for example, hammered into the ground.that damage to components, e.g. if the measuring module is run over by a tractor, is prevented.

[0053] A battery and / or a solar panel can be used as the power supply. The communication device can be used, in particular, for communication via a mobile network or a wide area network. Various possible protocols for this have already been discussed above. An antenna for the communication device can also be provided on or in the housing.

[0054] The measuring module can include, in particular, a positioning device, such as a GPS module. To enable configuration and / or status checks directly on the measuring module without additional components, status indicators, such as LEDs, operating elements, such as buttons, and / or a display can be provided on the measuring module. Furthermore, the measuring module can include a signaling device, such as a bright flashing light, or an audible warning device, such as a loud beeper, which can be activated, for example, via wireless communication to facilitate locating the measuring module.

[0055] Further advantages and details of the invention will become apparent from the following exemplary embodiments and the accompanying drawings. These schematically illustrate: Fig. 1 shows an embodiment of a device according to the invention for determining the amount of bound carbon dioxide, Fig. 2 shows the interaction of relevant algorithms and data structures within an embodiment of the method according to the invention for determining the amount of bound carbon dioxide, and Fig. 3 shows an exemplary configuration of the device described in Fig. 1. Fig. 1 shown measuring module.

[0056] Fig. 1 Figure 1 schematically shows a device for determining the quantity of chemically bound carbon dioxide within a time interval using a soil-side reaction agent 1. To provide a clear representation of the relevant components, the relative sizes and distances between the objects shown sometimes deviate significantly from their actual size ratios and distances.

[0057] Finely ground rock is used as the reactant 1, and as explained in the general section, its weathering absorbs carbon dioxide from the air. To provide the largest possible reaction surface, the reactant 1 is spread over a large area on the ground surface in several measurement areas 3, 4, 5, which in this example are separate, agriculturally used fields. The amount of carbon dioxide bound in each measurement area 3, 4, 5 depends on the properties of the reactant 1 itself and on a multitude of other parameters, such as soil composition, weather, and other factors.

[0058] To incentivize carbon dioxide sequestration, it is crucial to quantify the amount of carbon dioxide sequestrated, for example, to account for its sequestration within an emissions trading system. While it would be possible to assess relevant influences solely through soil sampling and subsequent laboratory analysis, this is because short-term factors, such as rainfall or plant growth, are also highly relevant to the amount of carbon dioxide sequestered. This would necessitate very frequent soil sampling, resulting in high costs and making it economically impractical.

[0059] In the example shown, a different method is therefore used to determine the amount of bound carbon dioxide. Here, soil-side sensors 7 are used to record, for example, measurements of the soil conductivity, which are then used to determine the amount of bound carbon dioxide. The use of local sensors makes it possible to acquire relevant measurements with high temporal and spatial resolution, thus providing a higher resolution both spatially and temporally than would be possible with reasonable effort by taking soil samples.

[0060] In addition to or as an alternative to measuring the conductivity of the soil 2, a cation concentration of at least one cation in the soil 2 can also be determined as a measured value, or other sensor data, which will be discussed below with reference to the Fig. 2 to be explained, to be taken into account. For the sake of clarity, in Fig. 1 For each measuring area 3, 4, 5, or for each measuring module 6 arranged therein, only its sensor 7 is shown. A measuring module 6 with a larger number of sensors will be described later with reference to Fig. 3 will be explained.

[0061] One possible approach to determining the amount of bound carbon dioxide is described below, with additional reference to Fig. 2 This explains the interaction of the relevant algorithms and data structures. The calculations are performed by a processing unit 10, which could be, for example, a server. A computer program 13 stored in a memory 12 is executed by a processor 11 to implement the steps of the procedure.

[0062] First, a reaction agent parameter 14 relating to reaction agent 1 is read in. This parameter may already be stored in the memory 12 of the processing unit 10 or retrieved from a server, for example via the internet, or similarly. In this example, it is assumed that the reaction agent parameter describes a time derivative of the amount of carbon dioxide chemically bound by the reaction agent under laboratory conditions. This can be determined, for example, in preliminary tests for a specific batch of reaction agents or for a specific type of reaction agent.

[0063] The reaction agent parameter or the basic value for the time derivative of the amount of bound carbon dioxide is then multiplied by several correction factors 26 to 30, as already explained in the general part of the description.

[0064] For the sake of simplicity, let us initially assume that only the correction factor 26 is used, which corresponds to the conductivity correction factor f discussed in the general section. For this purpose, a measured value 31 for the conductivity of the soil 2 is acquired by the respective sensor 7 of the respective measuring module 6 and wirelessly transmitted by a communication device 8 of the respective measuring module 6 to the processing unit 10. Thereupon, the correction factor 26 is calculated using a calculation formula provided by the program 13, and the base value is multiplied by this factor. The measuring module 6, and in particular the sensor 7 and the communication device 8, are powered by a power supply unit 9, in this example by a solar cell.

[0065] After multiplying the base value by the correction factor 26, or in the Fig. 2 In the more complex configuration shown, with all correction factors 26 to 30, the actual weathering rates or the time derivatives of the amount of bound carbon dioxide for the various measurement areas 3, 4, 5 and for the successive time intervals, for which the correction factor 26 potentially differs, are added together to determine the total amount 36 of bound carbon dioxide in the time interval. This amount can be made available to users via an output interface 37, for example via a web interface, or to other processing facilities, for example to automatically provide emission certificates based on the bound carbon dioxide.

[0066] To improve the accuracy of determining quantity 36, it is advantageous to additionally use the further correction factors 27 to 30, or at least parts thereof. Correction factor 27 corresponds to the correction factor f soil discussed in the general section. As already explained there, this depends in particular on a measured value 32 for the cation concentration of at least one cation in the soil 2. In particular, concentrations can be measured for those cations that are initially part of the reactant and precipitate as carbonate through binding of carbon dioxide.

[0067] It can be advantageous to use different sensors to determine the various measured values. A measuring module 6, comprising various sensors 7, 42 to 47, 50, 51, is in Fig. 3 This is shown schematically and will be explained in more detail later. The measured value 32 can, for example, be provided by sensor 45, which measures the cation concentration using, for example, an ion-selective electrode.

[0068] The correction factor 27 may also depend on additional information 15, which may, for example, be stored in advance in the memory 12 of the processing unit 10 or may be provided via a third unit not shown.

[0069] The preliminary information 15 can be present multiple times, for example, once for each of the measurement areas 3, 4, 5. In order to process the preliminary information together with the measured values ​​31, 32 or sensor data 33, 34, 55 for the respective measurement area 3, 4, 5, or to determine separate quantities of bound carbon dioxide for the individual measurement areas 3, 4, 5, the preliminary information 15 is assigned to a specific area 18 or provided separately for each area 18. Each measurement area 3, 4, 5 also contains a positioning device 49, for example, a GPS sensor, which can be integrated into the measurement module 6, as shown in Fig. 3 The positioning device 49 provides position information via the communication device 8 together with the measured values ​​31, 32 or the sensor data 33, 34, so that by means of a selection module 25 those preliminary information 15 can be selected for joint processing with the measured values ​​31, 32 or sensor data 33, 34 of a measurement area 3, 4, 5 whose area 18 corresponds to the respective measurement area 3, 4, 5.

[0070] The correction factor 27 is intended to reflect properties of the soil 2. Therefore, to determine the correction factor 27, preliminary information 15 can be provided, in particular, the porosity 20 and / or soil type 21 of the soil 2 and / or fungi 22 and / or bacteria 23 and / or vegetation 24 present in the soil 2. This preliminary information 15 can be obtained, for example, by examining soil samples in the laboratory, or it can be entered manually, for example, to take into account sown seeds as vegetation 24.

[0071] In addition to the dependencies shown, the correction factor 27 can also depend on the nutrient content of the soil 2, which can be determined, for example, via another sensor 50 located in Fig. 3 This sensor can, for example, measure the concentration of sodium, phosphorus and / or potassium compounds or ions supplied by nutrients from the soil.

[0072] The correction factor 28 corresponds to the correction factor fenvironment discussed in the general section. This factor is intended to generally account for the weather, or more specifically, a temperature and a precipitation amount. In the example, the temperature can be represented by the factor in Fig. 3 The temperature sensor 46 shown is used to record the precipitation. In principle, the amount of precipitation could also be measured locally; however, in this example, a satellite-based sensor 52 is used for this purpose.

[0073] Since such a satellite-based sensor 52 records precipitation amounts for a large number of areas, the sensor data 16 provided by the sensor 52 can also be processed by the selection module 25 in order to select suitable sub-data using the position information 17, which are taken into account when determining the correction factor 28.

[0074] Optionally, sensor data relating to the partial pressure of carbon dioxide in the air above ground level 2 can also be considered when determining correction factor 28 or when determining a further correction factor. These can be obtained, for example, from the in Fig. 3 The sensor shown, 51, will be detected.

[0075] The correction factor 54 corresponds to the correction factor fliquid explained in the general section. This depends on sensor data 55, which are determined by the Fig. 3 The sensors 42 to 44 shown can detect the moisture content. These sensors are moisture sensors, meaning the sensor data describes the moisture in the soil 2. Due to the vertical spacing of the sensors 42 to 44, a lysimeter can also be implemented, and the vertical water flow in the soil 2 can be determined and taken into account as part of the sensor data 55.

[0076] The correction factor 29 corresponds to the correction factor f pH explained in the general section and depends on sensor data 34 relating to the pH value in the soil 2, which are obtained, for example, via the in Fig. 3 The sensor shown, 47, can be detected.

[0077] The correction factor 30 depends on the alkalinity 19 of the soil 2, which is provided as preliminary information 15 in the example shown. Alternatively, the alkalinity could also be measured by sensors. The correction factor 30 thus corresponds to the correction factor f Alk explained in the general section.

[0078] Calculation rules for determining the individual correction factors 26 to 30 from the aforementioned quantities are provided by program 13. These rules can be determined, for example, through laboratory tests, using methods such as lookup tables, regression analysis, statistical analysis, machine learning, and similar techniques to generate calculation rules from these test series.

[0079] The measured values ​​or sensor data are preferably acquired several times a day or several times per hour by the respective measuring module 6 to enable a determination of the amount of bound carbon dioxide with high temporal resolution. Since the relevant parameters can differ locally, for example between different fields, as described in Fig. 1 As shown schematically, a separate measuring module 6 is used for each field. Generally, the distance 53 between measuring positions 38 to 40 or measuring modules 6 can preferably be less than 500 m.

[0080] With reference to Fig. 1 It was assumed that the energy supply device 1 is a solar cell. To enable measurements at night or in bad weather, for example, it is advantageous to use a battery as an additional or alternative energy supply device 48, as shown in Fig. 3 is shown schematically.

[0081] Both in the Fig. 1 as well as in the Fig. 3In the depicted measurement module 6, it is assumed that the communication device 8 also implements the reading of the various sensors 7, 42-47, 50, 51, the control of the power supply, and, if necessary, preprocessing of the sensor data to determine intermediate results. In principle, it is also possible to implement corresponding functions by a separate processing device integrated into the measurement module 6, for example, a CPU with assigned memory.

[0082] The electronic components of the measuring module can be at least partially integrated into a housing 41, which can protect the components from moisture on the one hand and / or prevent damage to the components, e.g. when hammered into the ground or driven over, e.g. by a tractor.

Claims

1. Method for determining an amount (36) of carbon dioxide chemically bound within a time interval using a reactant (1) on the ground, comprising the steps of: - reading in at least one reactant parameter (14) concerning the reactant (1), - capturing a respective measured value (31, 32) for the conductivity of the ground (2) and / or for a respective cation concentration of at least one cation in the ground (2) by means of at least one sensor (7, 45) mounted in or on the ground (2), and - determining the amount of bound carbon dioxide on the basis of both the reactant parameter (14) and the measured value (31, 32) or the measured values (31, 32).

2. Method according to Claim 1, characterized in that the amount (36) of bound carbon dioxide is determined on the basis of sensor data (33, 55, 56) from the sensor (7, 45) and / or at least one further sensor (42-44, 50, 52, 57), wherein the sensor data (33, 55, 56) relate to a vertical flow of water in the ground (2) and / or an amount of precipitation and / or moisture in the ground (2) and / or an alkalinity and / or a nutrient content of the ground (2) and / or a partial pressure of carbon dioxide in the air above the ground (2).

3. Method according to Claim 1 or 2, characterized in that the amount (36) of bound carbon dioxide is determined on the basis of sensor data (33, 34) from the sensor (7, 45) and / or the further sensor (42-44, 50, 52, 57) and / or at least one further sensor (46, 51), wherein the sensor data (33, 34) relate to a pH value and / or a temperature of the ground (2).

4. Method according to one of the preceding claims, characterized in that the reactant parameter (14) specifies a basic value for the amount (36) of bound carbon dioxide or for the time derivative of this amount, which is multiplied in the course of the calculation by at least one correction factor (26-30, 54), wherein at least one of the correction factors (26-30, 54) depends in each case on the measured value (31, 32) or at least one of the measured values (31, 32) and / or at least parts of the sensor data (33, 34, 55, 56).

5. Method according to one of the preceding claims, characterized in that the concentration of sodium ions and / or calcium ions and / or magnesium ions is captured as the cation concentration.

6. Method according to one of the preceding claims, characterized in that the respective measured value (31, 32) and / or the sensor data (33, 34, 55, 56) and / or at least one intermediate result determined from the measured value (31, 32) and / or the sensor data (33, 34, 55, 56) from a measuring position (38, 39, 40), at which the respective sensor (7, 42-47, 50, 51) or the respective sensors (7, 42-47, 50, 51) is or are arranged, is / are transmitted wirelessly to a processing device (10) which determines the amount (36) of bound carbon dioxide.

7. Method according to one of the preceding claims, characterized in that the measured value (31, 32) or the measured values (31, 32) and / or at least parts of the sensor data (33, 34, 55, 56) is / are captured several times a day or several times per hour and the amount (36) of bound carbon dioxide is determined on the basis of this.

8. Method according to one of the preceding claims, characterized in that the measured value (31, 32) or at least one of the measured values (31, 32) and / or the sensor data (33, 34, 55, 56) at a plurality of measuring positions (38, 39, 40) is / are captured by a respective sensor (7, 42-47, 50, 51), wherein the measuring positions (38, 39, 40) are in particular less than 500 m or less than 200 m apart.

9. Method according to one of the preceding claims, characterized in that a soil sample is taken from the ground (2), in particular in the region of a respective measuring position (38, 39, 40), at which the respective sensor (7, 42-47, 50, 51) or the respective sensors (7, 42-47, 50, 51) is or are arranged, prior to capturing the respective measured value (31, 32) and / or the sensor data (33, 34, 55, 56), and is examined, in particular at a distance from the sampling location in a laboratory, in order to determine an alkalinity (19) and / or a porosity (20) and / or a soil type (21) of the ground (2) and / or fungi (22) and / or bacteria (23) present in the ground (15) as preliminary information (2), wherein the amount (36) of bound carbon dioxide is determined on the basis of the preliminary information (15).

10. Method according to one of the preceding claims, characterized in that respective preliminary information (15), in particular relating to an alkalinity (19) and / or a porosity (20) and / or a soil type (21) of the ground (2) and / or fungi (22) and / or bacteria (23) present in the ground (2) and / or planting (24) of the ground (2) and / or the weather, and / or the respective preliminary information (15) determined on the basis of the soil sample is provided separately for a plurality of areas (18), wherein in a measuring area (3, 4, 5), which comprises the sensor and / or the further sensor (7, 42-47, 50, 51), use is additionally made of a position determining device (49) which provides position information (17) relating to the respective measuring area (3, 4, 5), wherein the preliminary information (15) assigned to the measuring area (3, 4, 5) is selected on the basis of the position information (17), after which, on the basis of said preliminary information and the at least one measured value (32, 33) captured in the measuring area (3, 4, 5) and / or at least parts of the sensor data (33, 34, 55, 56) captured in the measuring area (3, 4, 5), the amount (36) of bound carbon dioxide or an intermediate result, on which the determined amount (36) of bound carbon dioxide depends, is determined.

11. Apparatus for determining an amount (36) of carbon dioxide chemically bound within a time interval using a reactant (1) on the ground, comprising at least one sensor (7, 45) for capturing measured values (31, 32) for the conductivity of the ground (2) and / or for a respective cation concentration of at least one cation in the ground (2) and a processing device (10), characterized in that the apparatus is configured to carry out the method according to one of the preceding claims.

12. Apparatus according to Claim 11, characterized in that it comprises at least one measuring module (6) comprising a housing (41), which is designed to be inserted into the ground (2), at least one sensor (7, 42-47, 50, 51), a communication device (8) for wirelessly transmitting measured values (31, 32) captured by means of the sensor (7, 42-47, 50, 51) and / or sensor data (33, 34, 55, 56) and / or an intermediate result determined from the measured value (31, 32) and / or the sensor data (33, 34, 55, 56) to the processing device (10), and at least one energy supply device (9, 48) for supplying the communication device (8) and the sensor (7, 42-47, 50, 51).