Method and device for determining the adsorption amount of sorbents in at least one storage substance and computer program product

Abstract

The invention relates to a method for determining the adsorption amount (AM) of sorptives (S) in at least one storage substance, in which the adsorption amount (AM) of the sorptives (S) is determined on the basis of several physical data assigned to different points in time and / or time periods, taking into account both physical and chemical parameters of the at least one storage substance and a theoretical and / or data-based adsorption behavior of the at least one storage substance.

Description

Technical FieldThe invention relates to a method for determining the adsorption amount of sorbent materials in at least one storage substance, which can be used in particular in connection with the removal of CO 2 from the atmosphere and the storage of CO 2 in storage substances. The invention further relates to a device, in particular a data processing system for carrying out the method according to the invention, and to a computer program product.Prior ArtAs part of climate conversion, there is a more and more search for possibilities of reducing the CO 2- increase in the atmosphere or withdrawing the CO 2 present in the atmosphere from the atmosphere and storing it in suitable storage media. The calculation methods used for this are typically described by simple sorption models by means of experimental laboratory data and constant or fixed temperature. Such calculation methods, which are designed to be relatively simplified, appear to be capable of improvement with regard to their accuracy with regard to the complexity of the processes which take place.Disclosure of the InventionThe method according to the invention for determining the adsorption quantity of sorptivs in at least one storage substance having the features of claim 1 has the advantage that, using a theoretical and / or data-based adsorption behavior, it calculates the adsorption quantity more realistically on the basis of a carrier medium containing the sorptivs and thereby makes possible a far more accurate statement with respect to the expected adsorption quantity of the sorptivs. This is because, in contrast to the methods known from the prior art, no constant parameters of the carrier medium are used as a basis, but rather parameters which prevail at different times and / or time periods.In particular, the method according to the invention is thus also suitable for evaluating / selecting possible locations for corresponding installations for storing CO 2, since location-specific weather data of the air as carrier medium of the CO 2 are taken into account in this case.Against the background of the above explanations, the method according to the invention for determining the adsorption amount of items of sorbent in at least one storage substance has the features that, taking account of both physical and chemical parameters of the at least one storage substance and taking account of a theoretical and / or data-based adsorption behavior of the at least one storage substance, the adsorption amount of the items of sorbent is determined on the basis of a plurality of physical data of a carrier medium assigned to different times and / or time periods, wherein the physical data comprise at least one temperature of the carrier medium which contains the items of sorbent and which chemically reacts with the at least one storage substance or is designed to react chemically with the at least one storage substance.Advantageous further developments of the method according to the invention are set forth in the dependent claims.The method according to the invention is preferably used in the determination of the adsorption amount of CO 2 as a sorbent, wherein the physical data of the carrier medium are the weather data of a location, and wherein the weather data comprise at least the air temperature.The method has a particularly high accuracy if a pressure of the carrier medium at the different times and / or time periods is additionally taken into account.With regard to the weather data, it is possible on the one hand to use historical weather data of weather recording services. However, additionally or instead predicted weather data may also be used, which in particular relate to a period of time at which CO 2- storage is to be performed at a potential location. This may be useful, in particular, if future heating / climate changes can be predicted for a location.In a development of the last proposal, it can be provided that the weather data evaluated or predicted at specific times and / or periods are used to determine the adsorption quantity. Thus, in particular, for example, the amounts of the sorptivs adsorbed at different times of year and / or time of day can be determined and evaluated.This can also be used to compare different locations for possible adsorption amounts using location specific weather data, respectively.With regard to the weather data, the following is explained: The data record of the weather at a location can be based on its own measurements or databases (e.g. of the German weather service). Ideally, it contains temperature, humidity and air pressure along with a time stamp. If the air pressure is not available, a weather-independent CO 2- partial pressure, e.g. 0.4 mbar, can approximately also be used. If a permanent or time-varying deviation of the CO 2- content from the natural mean value is to be assumed at the location, data from sensors or satellite recordings or modelling data can also be used. If geometry and operating parameters are also known in a plant for CO 2- storage, preprocessing of the weather data can additionally be carried out, for example increased a dynamic pressure at the inlet of the plant in the calculation of the CO 2- partial pressure or an air temperature deviating from the ambient temperature at the location of the sorption agent.At high temperatures and air humidity (e.g. above 50° C.), it is appropriate for particularly precise values of the mole fraction or the molar fraction of CO 2 to still use a dilution factor of the CO 2 by the water fraction in the air (e.g. an absolute humidity 4% in the air leads to a reduction from 400 ppm of CO 2 to only 400 / 1.04 ppm). Conversely, for accelerating the calculation, this can be dispensed with exactly. To speed up the calculation, the model can be accelerated by numerical approximations. For example, the complete model can be specified on a grid of interpolation points of temperature and air humidity with a specific grid. For approximating or interpolating between these interpolation nodes, a numerically simple, fitted model can be used (e.g. polynomial model 1.-3. Grades, Machine Learning Model).If different possible locations are to be compared or evaluated with respect to their suitability for CO 2- storage, it is provided on the one hand to use location-specific weather data and on the other hand, for reasons of simplification, however, to assume fixed physical and chemical parameters of the at least one storage substance.With regard to the calculation of the adsorption quantity, it is provided, in particular in connection with CO 2 as a sorptiv, that the adsorption quantity is calculated on the basis of the static physics, wherein it is calculated at which proportions different possible adsorptions of the at least one storage substance and vacancies are distributed to similar receptors.It is also mentioned that the method according to the invention maps the thermodynamically possible state of filling between 0% and 100% of a storage material with CO 2 depending on the ambient temperature and atmospheric humidity. Kinetic aspects are not taken into account here; the physical model therefore yields the maximum possible filling in the favorable case.In a development of the last-described method, it is provided that for each possible adsorpt of the at least one storage substance, the stoichiometry of all the participating sorptivs is taken into account, the entropy of the receptors is calculated and the chemical potentials of the storage substance for each adsorpt are linked to the chemical potentials of the gases involved in the process.In a further development of the method, it is also provided that items are taken into account which are chemically bound by more than one receptor of the additives of the at least one storage substance.In a development of the last proposal, it can be provided that the distances and spatial arrangement of the receptors are combined to form individual cluster types and that the cluster types are taken into account as receptors.By means of the method according to the invention, it is also possible to predict time windows (for example, specific months per year or specific times) in which a particularly high or low storage quantity is to be expected, and whether the storage quantities are uniform or fluctuating.It is further explained that the method generally described in claim 1 can serve not only for determining or calculating the storage of CO 2 but also for other substances or solvents and for other technical devices in the field of filtering. The method according to the invention can also be used for liquid-chemical or dissolved substances in liquids.Furthermore, the invention comprises a device, in particular a data processing system, which is designed to carry out a method according to the invention.Finally, the invention also comprises a computer program product, in particular a data program or a data carrier, comprising instructions which cause the apparatus to execute at least one of the method steps according to the invention.Further advantages, features and details of the invention are evident from the following description of preferred embodiments of the invention and from the drawings.Brief Description of the DrawingsFIGS. 1 and 2 show flow diagrams respectively for explaining possible procedures of selection of location of installations for storing items on the basis of weather data, FIG. 3 shows a representation of a thermodynamic model system, consisting of a gas phase and sorbent, FIG. 4 shows a diagram of the CO 2- activation of receptors at various assumed binding energies over the temperature curve, FIGS. 5 and 6 show diagrams of the CO 2- occupancy of the receptors at different binding energies and different partial pressures, FIG. 7 is a diagram of the occupancy at different CO 2- partial pressures at a defined water vapor partial pressure, FIG. 8 is a representation of different receptors in irregular spatial arrangement, which are clustered and categorized; and Figures 9a and 9b show successive steps for modeling adsorption when two receptors are involved for formation in one of the adsorptes.Embodiments of the InventionFIG. 1 shows a flow chart of a basic method for linking data relating to the determination of an adsorption quantity AM of CO 2 as the sorbent S in at least one storage substance or adsorpt AS in conjunction with the consideration of weather data WD.In FIG. 1, block 100 includes data that takes into account chemical parameters of possible Adsorpte AS and stoichiometries. Block 102 includes data regarding physical input parameters of possible Adsorpte AS. The physical input parameters comprise in particular binding energies or enthalpies, wherein the input parameters mentioned are either known or present as assumed input parameters.The data from the two blocks 100, 102 are fed to a block 104 as input variables. The block 104 comprises a computer program as part of a data processing system, wherein the computer program has an algorithm which enables the determination of the administration set AM as a function of the administration set or sets AS and the sorption S.Weather data WD are supplied as input to block 104 via a block 106. Within the scope of the invention, weather data WD are understood to mean weather data WD of a possible (geographical) location SO of a plant for storing the items S, in particular for CO 2- storage. The weather data WD may be either historical weather data WD or predicted weather data WD (for future). The weather data WD comprise weather data WD recorded daily for longer periods of time, for example for several years, which weather data comprise at least the air temperature T and the air pressure P. Preferably, the weather data WD also comprise the air humidity LF. The air represents a carrier medium for the CO 2 in the atmosphere.In block 104, adsorption quantities AM are determined by means of the algorithm, for example for each day for which the weather data WD are present. These adsorption quantities AM can be summed up, mean values formed or statistically evaluated, for example, for specific periods of time. This is done in a block 108.The data obtained in block 108 are then further processed in a block 110. The block 110 serves for the agglomeration of the determined data by means of a fixed data filter. For this purpose, data are supplied to block 110 via a block 112 as input variables, which data comprise technical or economic criteria for operating a plant for removing CO 2 from the atmosphere.The data obtained in block 110 can then be further processed in a block 114. Block 114 represents a second data filter and serves for further bundling or evaluating the data. For this purpose, data are supplied to block 114 via a block 116, which data serve a valuative classification for achieving target values on the basis of techno-economic considerations. The data obtained in block 114 are then displayed or output in a block 118, wherein a degree of achievement of performance goals is documented in block 118. The blocks 100 to 118 described thus far can be realized in the form of a computer program product in the data processing system or on a computer.FIG. 2 shows a method for evaluating or evaluating different locations SO, based on the basic method explained in connection with FIG. 1. The method according to FIG. 2 comprises a block 120 containing data records of weather data WD from different possible or potential locations SO (which may lie in different climate zones). The data sets present as input variable in block 120 are then subjected in a block 122 to an evaluation method with respectively identical or fixed physical and chemical parameters (the Sorptive S and the Adsorpte AS). Block 124 represents an output block that contains a level of achievement of performance objectives for each material variant. Finally, in a block 126, a ranking list of locations SO or climate zones is generated.In summary, the methods illustrated in FIG. 1 and FIG. 2 serve to select suitable locations SO for plants for removing, in particular, CO 2 as a sorbent S from the atmosphere serving as a carrier medium or to compare them with one another.With regard to the determination or calculation of adsorption quantities AM of sorbent materials S from at least one storage substance or an adsorpt AS, reference is first made to FIG. 3 below. FIG. 3 shows the quantity of gas stored in an adsorpt AS from a thermodynamic point of view. A first subsystem 11 shown on the left side of FIG. 3 represents the gas phase, which can consist of a plurality of gas types of different concentrations (e.g. nitrogen, oxygen, CO 2, water). There is a sorbent with similar receptors in the second subsystem 12 shown on the right-hand side of Figure 3, the two subsystems 11, 12 interacting, which is intended to be illustrated by the double arrow 15. At each receptor n 1, n 2 etc., some of the gases may be adsorbed. However, there are only discrete possibilities for this whether an occupancy can be made by one or more of the gases. Each variant is referred to as Adsorpt AS. The adsorpt AS is subjected to a binding energy E b,i or. The absorption enthalpy is assigned to ΔH i. There may be k different Adsorpte AS. Not all kinds of gas need be involved in adsorptin formation (e.g. oxygen, nitrogen). The receptors may remain unoccupied.For the determination of the adsorption quantity AM, it is first necessary to clarify which proportion of the receptors is unoccupied and which proportion is occupied by the adsorpt types i=1,2,... k, to be precise depending on the temperature T and depending on the initial number of all molecules of each gas type in the gas phase. According to thermodynamic laws, the equilibrium condition is that the gas molecules must be distributed between the gas phase and the sorbent in such a way that the free energy F=E-TSis minimal. Here, E is the total energy of both subsystems 11, 12, S is the total entropy of both subsystems 11, 12, and the free energy F can be calculated individually for both subsystems 11, 12 and can be equalized with attention to the signs for the particle flow direction.If a large gas reservoir is present with a practically fixed concentration (despite the adsorption), it is practicable to use the free enthalpy G (pi, T)=F+pV and to expect concentrations of the gases instead of particle numbers. If a change in volume is neglected for the sorption agent (at least an increase in volume would have significantly less than the volume of the absorbed sorbent S claimed as gaseous), no further differentiation between free energy and free enthalpy need be taken into account for it in the equations.As equilibrium condition, the derivation of F (or G) with respect to all the adsorbed AS in the sorbent (right subsystem 12) must be considered to be equal in connection with the corresponding negative derivations with respect to the gases (left subsystem 11). In this case, stoichiometric coefficients must also be taken into account, since not every adsorpt AS must be composed of exactly one substance.Taking the example of two gases A and B and k different Adsorpten AS, a system of k reaction equations results.In the sorbent, the energy can be balanced as a weighted sum of all binding energies with the respective requirements: E sorb=- m 1 ·E 1- m 2 ·E 2...- m k ·E k The entropy can be measured via S sorb= k B. In(Ω). Here, k B is the Boltzmann constant and Ω is the number of possible states of micro which can be occupied by m 1, m 2,... m k Adsorpten AS of the types 1, 2,... k. The number of unoccupied receptors is inevitably given as (M-m 1- m 2... m k):The k chemical potentials of the Adsorpte AS are obtained from the partial derivatives of the free energy / enthalpy of the subsystem of the sorbent according to m 1, m 2,... m k. These must be connected to the derivatives of the free energies of the gases (or the chemical potentials) of the gases. Here, the stoichiometric factors v ij must be taken into account.The temperature-dependent chemical potentials of the gases can be determined from relevant literature tables for gases. If the gases do not behave ideally, these properties are placed in the referenced chemical potentials.From the k equations, the relative proportion α i= m√M) of the receptors can be determined for each adsorpt AS and the vacancies, if the gas concentrations and the temperatures T are known.FIG. 4 shows a diagram with a first example of an ideal selective sorption agent which binds only one type of gas (here: CO 2) and no further gas, with exactly one CO 2- molecule being bound per receptor. There is competition from occupied receptors and free receptors. In FIG. 4, the temperature curves of the relative CO 2- loading (load / rel.) of the receptors are plotted, specifically for a CO 2- partial pressure of 0.4 mbar (corresponds to 400 ppm at 1 bar total pressure) at various assumed binding energies (B b / eV). The curves approach asymptotically horizontal lines at high and low temperatures T and show a strong gradient in a transition region which has an almost linear course with the temperature T between approximately 20% and 80%. These slopes change slightly with the binding energy B b / eV and they become flatter and flatter the weaker the binding energy B b / eV is.In Figures 5 and 6, as a second example, another ideal selective sorbent is one which binds exactly one composite adsorpt per formulation consisting of an H 2 O molecule and a CO 2- molecule each. The upper and lower plots differ in binding energy from -0.4 eV and -0.3 eV, respectively. Three different partial pressures of water vapor are recorded in each of the diagrams, at a fixed partial pressure CO 2(0,4 mbar). It can be seen here that the loading (load / rel.) also depends strongly on the partial pressure of the water.FIG. 7 shows in a complementary manner how the loading (load / rel.) at a fixed water partial pressure changes with the temperature T if different CO 2- partial pressures are present. This corresponds qualitatively to a law of mass action (shift of equilibrium by increasing the concentration of at least one reactant).The peculiarities in the adsorption processes and the equations of the model described thus far compared to conventional chemical reactions including the law of action of mass is a non-monotone behavior of the entropy depending on the loading of the sorbent:a sorbent completely covered with an adsorpt type and a completely empty sorbent each having zero entropy (there is only one microstate matching the macrostate)the state for maximum entropy in the sorbent is the equal distribution of all Adsorpte AS with m i= M / k or α i= 1 / k.the derivation of the entropy after the occupancy becomes infinitely positive / negative at the edges of the computational assignments (limit considerations m i →0 or m i →M). The sorbent resists exactly complete filling / emptying much more strongly than a partially filled sorbent. Therefore isobars become horizontal at very low and very high temperatures T and have a steep profile in a temperature window of only a few tens of Kelvin.With the same formalism, transition states or internal degrees of freedom (e.g., vibrations of an adsorbed molecule group) can also be easily integrated if this state differs from the base level by an energy amount ΔE. Each such additional state can be formally considered as another (k+1)-th Adsorpt AS by using the same stoichiometry coefficients as for the ground state, but with ΔE attenuated binding energyThe model from the last section does not yet cover all cases known for CO 2- adsorption on amines, despite generality. Adsorpt AS "ammonium cabamate" can also form on primary amines. A CO 2- molecule is thereby claimed at two adjacent amine groups (receptors), for which not too large distances between the amine groups are required. For thermodynamic modelling, the assumption from the last section (all receptors are similar) must be modified. In addition, spatial proximity of the receptors to one another must be taken into account.The case is considered below in which only the two Adsorpte AS "hydronium carbamate" and "ammonium carbamate" can form in competition with one another and in competition with unoccupied receptors. Figure 8 shows the grouping of receptors into clusters. In a single cluster, adjacent receptors are grouped together if their spacings are compatible with pairwise adsorption. A cluster may be composed of 1, 2, 3,... Receptor objects exist. The single isolated receptor (type A) is a special case when there is no adjacent pair formation, it cannot be ammonium carbamate formation but only hydronium carbamate formation or void retention. The number of receptors in a cluster is, however, not sufficient for categorization, which is shown in FIG. 9 a. Starting from three receptors in a cluster, the receptors can be arranged, for example, as a chain, as a triangle, as a pyramid, for which categories must be defined in each case (C 1, C 2).The entire sorbent can thus be modeled as a weighted sum of the individual cluster categories. If no more detailed details about the structure of the sorbent are known, models for different cluster frequencies are calculated in practice and the weights must be determined as fit parameters.It is particularly advantageous that the same calculation path as for an individual receptor can be used for each cluster category. For this purpose, all adsorpt configurations must be formally considered to be another adsorpt AS with its own binding energy. This is illustrated using the example of cluster type B in FIG. 9 b. All conceivable combinations are considered of how vacancies and Adsorpt AS could be distributed: hydronium carbamate (occupies one receptor with H 2 O+CO 2) and ammonium carbamate (occupies two receptors with one CO 2), wherein here also a mirror asymmetry was taken into account (a.c. rev)). For cluster type B, six adsorption configurations result. Competition from these six adsorption configurations is calculated according to formalism from the last section for p(CO 2), p(H 2 O), and temperature T, taking into account stoichiometries with respect to H 2 O, and CO 2. If the proportions of the individual coats α 0 to α 5 are known, then in further steps the equivalents for ammonium carbamate, hydronium carbamate or for H 2 O and CO 2- equivalents can be balanced as the total average.When setting up a cluster model, however, it must be noted that the quantity of all conceivable cluster adsorpt assignments increases rapidly with the number of individual receptors. While only six configurations (labeled "occ." in Figure 9a) are for type "B", for the clusters with four receptors (types "D 1" through "D 4"), they may already be forty-four to seventy-six configurations (=formal Adsorpte AS). Simulations have shown that different cluster types can also show a similar behavior. It may be sufficient to restrict itself to a small number of cluster types and to use fewer weight factors (to be determined from experiments) for this purpose.It is mentioned in addition that it is additionally conceivable to combine the theoretical model of the load, which can be calculated in a fine grid as described so far, with a data-driven model of the reaction speeds.The methods described thus far can be modified in various ways without departing from the inventive concept. This consists in a model in which, for the calculation of the adsorption quantities AS of sorbent materials S in at least one storage substance, firstly chemical and physical parameters of the at least one storage substance and also additionally weather data WD of a carrier medium are taken into account.

Claims

Method for determining the adsorption quantity (AM) of items of sorbent (S) in at least one storage substance, in which, taking account of both physical and chemical parameters of the at least one storage substance and taking account of a theoretical and / or data-based adsorption behavior of the at least one storage substance, the adsorption quantity (AM) of the items of sorbent (S) is determined on the basis of a plurality of physical data of a carrier medium assigned to different times and / or time periods, wherein the physical data comprise at least one temperature (T) of the carrier medium which contains the items of sorbent (S) and which chemically reacts with the at least one storage substance, which temperature is present at the different times and / or time periods, to select the storage substance depending on the determined adsorption amounts (AM) of the sorptiva (S).Method according to Claim 1, characterized in that a pressure (P) of the carrier medium at the different times and / or time periods is additionally taken into account.Method according to Claim 1 or 2, characterized in that the adsorption quantity (AM) of CO 2 is determined as a sorptiv (S) and in that the physical data of the carrier medium is weather data (WD) of a location (SO), the weather data (WD) comprising at least the air temperature.Method according to claim 3, characterised in that the weather data (WD) is historical weather data and / or predicted weather data (WD).Method according to Claim 4, characterized in that the weather data (WD) evaluated and / or predicted at specific times and / or periods are used to determine the adsorption quantity (AM).Method according to one of Claims 3 to 5, characterized in that location-specific weather data (WD) are used for comparing different locations (SO) with respect to possible adsorption quantities (AM).Method according to claim 6, characterised in that solid physical and chemical parameters of the at least one storage substance are used for the comparison.Method according to one of the preceding claims, characterized in that the adsorption quantity (AM) of the sorptives (S) is calculated on the basis of the statistical physics, it being calculated in which proportions different possible adsorptes (AS) of the at least one storage substance and vacancies are distributed over similar receptors.Method according to Claim 8, characterized in that, for each possible adsorpt (AS) of the at least one storage substance, the stoichiometry of all the items (S) involved is taken into account, the entropy of the receptors is calculated, and the chemical potentials of the storage substance for each adsorpt (AS) are linked to the chemical potentials of the gases involved in the process.Method according to one of claims 8 or 9, characterised in that sorptives (S) are bound by more than one receptor of the adsorpte (AS) of the at least one storage substance.Method according to claim 10, characterised in that the distances and spatial arrangement of the receptors are combined into individual cluster types and that the cluster types are taken into account as receptors.Device, in particular a data processing system, designed to carry out a method according to one of Claims 1 to 11.Computer program product, in particular data program or data carrier, comprising instructions which cause the apparatus according to claim 12 to carry out at least one of the method steps according to one of claims 1 to 11.

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