Method for operating a twinned digital-physical system comprising a chromatograph

Abstract

A method for operating a twinned physical-digital system that comprises a chromatograph and a digital twin of the chromatograph. In that method, the digital twin is utilized to mimic a contamination of a sample based on virtual representations of different substances. In order to determine which substance the contaminant is, the physical contamination is mimicked through the digital twin. Systematically, virtual representations of virtual contaminants are selected and the operation of the chromatograph with the potential contaminants is simulated. When a virtual chromatogram that encompasses a virtual peak for virtual representation of a potential contaminant matches the physical chromatogram that shows the contamination, the potential contaminant is deemed to reflect the physical contaminant.

Description

202400755METHOD FOR OPERATING A TWINNED DIGITAL-PHYSICAL SYSTEM COMPRISING A CHROMATOGRAPHTECHNICAL FIELD

[0001] The present disclosure relates to a method for operating a twinned physical-digital system. The present disclosure also relates to a method for diagnosing a chromatograph of a physical-digital system. Furthermore, the present disclosure relates to a computer program product for operating a twinned physical-digital system. Still further, the invention relates to a method for operating a chemical production system.Background

[0002] US 2017 / 0286572 Al discloses a twinned physical-digital system that comprises sensors to sense values of designated parameters of the twinned physical-digital system. The twinned physical-digital system is configured to mirror an operation of a jet engine.

[0003] Chromatographs are used in a variety of chemical production processes to determine compositions of samples. Due to the complexity of chromatographs and the underlying chemical production processes, it requires a significant amount of training and experience of a user to correctly assess uncommon readings at a chromatograph. In at least some applications, there might be a need for a solution that at least supports a user during the operation of the chromatograph. It is an object of the present disclosure provide a method for operating a chromatograph that offers an improvement in at least one of the aspects outlined above.202400755SUMMARY

[0005] At least one of the objects described above is achieved by a method for operating a twinned physical-digital system which comprises a chromatograph and a digital twin of the chromatograph. The method comprises a first step in which a composition of a sample fed into the chromatograph is determined, i.e. measured. The chromatograph generates chromatograms which reflect the measured composition. The first step also comprises that at least one of the chromatograms comprises a number of peaks which corresponds to the number of substances in the sample when the sample is only comprises substances according to a preset specification. Each of the peaks caused by the specified substances is substantially located at a specified position in the chromatograms. The specified positions reflect an elution time of the respective substance. In a second step of the invention, a presence of at least one unspecified substance in the sample is detected when a peak is detected at an unspecified position in at least one chromatogram. Furthermore, the peak at the unspecified position is isolated in the at least one chromatogram. The method also comprises a third step in which a multiplicity of substances is selected as potential unspecified substances from a database. During the third step, virtual representations of the substances from the selected multiplicity of substances is fed into the digital twin. In a fourth step of the disclosed method, the digital twin of the chromatograph is run with the virtual representations and virtual chromatograms are generated. The method further comprises a fifth step in which degrees of membership between the virtual chromatograms and the chromatogram that comprises the at least one peak at the unspecified position are determined. Furthermore, at least one virtual chromatogram is determined that shows at least a selectable minimum degree of membership. Still further, a substance is determined that corresponds to the at least one determined virtual chromatogram as the unspecified substance. In a sixth step of the disclosed method, the determined substance is output to at least one of a user and a data interface.

[0006] At least one of the objects described above is also achieved by a method for diagnosing a chromatograph of a twinned physical-digital system, which comprises a digital twin of the chromatograph. The method comprises a first step in which the chromatograph is operated and at least one chromatogram reflecting the composition of a sample that is fed into the chromatograph202400755 is generated. In a second step of the disclosed method, the digital twin is run to mirror the operation of the chromatograph. During the second step, the at least one chromatogram generated by the chromatograph is compared to a corresponding virtual chromatogram. The virtual chromatogram is generated by the digital twin. In a third step, a deviation between at least one peak in the chromatogram and a corresponding peak in the virtual chromatogram is determined. The method further comprises a fourth step in which at least one of an ambient parameter and an operating parameter of the digital twin is varied to match the virtual chromatogram to the corresponding chromatogram. In addition to that, at least one of varied ambient parameter and the varied operating parameter of the digital twin is determined in the fourth step. In a fifth step of the disclosed method, a type of at least one of the varied ambient parameter and the varied operating parameter are output to at least one of a user and a data interface.

[0007] Still further, at least one of the objects described above is also achieved by a computer program product that is stored on a non-transitory storage medium. The computer program product comprises program code that is configured to perform the following steps when it is loaded into a memory of a computer. The first step comprises receiving signals from a chromatograph and generating chromatograms based on the received signals. The first step also comprises detecting a number of peaks in at least one of the chromatograms, wherein the number reflects the number of substances in a sample analyzed in the chromatograph when the sample only comprises specified substances according to a preset specification. Each of the peaks caused by the specified substances is substantially located at a specified position in the chromatograms. The positions reflect an elution time of the respective substance. A second step comprises detecting a presence of at least one unspecified substance in the sample when a peak is detected at an unspecified position in at least one chromatogram. In addition to that, the peak at the unspecified position is isolated during the second step. The program code is further configured to perform a third step in which a multiplicity of substances is selected from a database, the selected multiplicity of substances being potential

[0008] unspecified substances. Virtual representations of the substances from the selected multiplicity of substances are fed into the digital twin. A fourth step comprises running a digital202400755 twin of the chromatograph with the virtual representations and generating virtual chromatograms. The program code is further configured to perform a fifth step in which degrees of membership between the virtual chromatograms and a chromatogram comprising the at least one peak at the unspecified position is determined. In addition to that, at least one virtual chromatogram is determined that shows at least a selectable minimum degree of membership. Still further, the substance that corresponds to the at least one determined virtual chromatogram is determined as the unspecified substance. Moreover, the program code is configured to perform a sixth step in which the determined substance is output to at least one of a user and a data interface.

[0009] At least one of the objects outlined above is also achieved by a method for operating a chemical production system that is configured to perform a chemical production process. The chemical production system comprises a first stage at which an intermediary product is produced, and a second stage at which the intermediary product is processed. The chemical production system further comprises a measurement stage that is arranged between the first stage and the second stage, the measurement stage comprising a chromatograph and being configured to determine a composition of a sample of the intermediary product through the chromatograph. The method comprises a first step in which the composition of a sample is determined and at least one chromatogram is generated which reflects the number of substances in the sample when the sample is only comprises specified substances according to a preset specification. Each of the peaks caused by the specified substances is substantially located at a specified position in the chromatograms. The positions reflect an elution time of the respective substance. In a second step, a presence of at least one unspecified substance in the sample is detected when a peak is detected at an unspecified position in at least one chromatogram. Furthermore, at least one additional peak is isolated in the second step. The method further comprises a third step in which a multiplicity of substances is selected from a database as potential unspecified substances. The selected multiplicity of substances is fed into a digital twin of the chromatograph. In a fourth step of the disclosed method, the digital twin of the chromatograph is run with virtual representations of the substances from the selected multiplicity of substances. Furthermore, the digital twin of the chromatograph generates virtual chromatograms during the fourth step. In a fifth step of the202400755 disclosed method, degrees of membership between the virtual chromatograms and a chromatogram that comprises the at least one peak at the unspecified position are determined. In addition to that, at least one virtual chromatogram is determined that shows at least a selectable minimum degree of membership between the chromatogram with the at least peak. The substance corresponding to the determined virtual chromatogram is determined as the unspecified substance. In a sixth step of the disclosed method, the contaminant determined in the fifth step is output to at least one of a knowledge database and an artificial intelligence algorithm. Furthermore, at least one a root cause for the presence of the unspecified substance in the sample is determined. Still further, a countermeasure to remove the unspecified substance from the chemical production process run in the chemical production system is determined during the sixth step.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In the following, the present disclosure is described in more detail in several figures. The figures are to be construed as mutually complementary. Particularly, identical numerals are to be construed as having the same technical meaning. The features of the embodiments shown in the figures may be combined with each other. Additionally, the features of the embodiments shown in the figures may also be combined with the embodiments outlined above and below. In particular, the figures show:

[0011] FIG. 1 an embodiment of a disclosed method for operating a twinned physical-digital system during a first stage;

[0012] FIG. 2 the embodiment of a disclosed method for operating a twinned physical-digital system during a second stage;

[0013] FIG. 3 a schematic overview of a step of the embodiment of the disclosed method for operating the twinned physical-digital system;

[0014] FIG. 4 an embodiment of a disclosed method for diagnosing a chromatograph during a first stage;202400755

[0015] FIG. 5 the embodiment of a disclosed method for diagnosing a chromatograph during a second stage;

[0016] FIG 6 an embodiment of a disclosed method for operating a chemical production system.DETAILED DESCRIPTION

[0017] The disclosed method is configured for operating a twinned physical-digital system, which comprises a chromatograph as a physical component and a digital twin of the chromatograph as a digital component. The digital twin comprises a virtual representation of at least a part of the chromatograph that is configured to emulate the functioning of the chromatograph, i.e. the physical component of the twinned physical-digital system. The digital twin may comprise a data interface that connects the digital twin to the chromatograph. In context with the present disclosure, the term “digital twin” may be construed pursuant to US 2017 / 0286572 Al. The contents of US 2017 / 0286572 Al are hereby incorporated into the present disclosure by reference. The chromatograph may be configured to determine a composition of a sample, the sample being either a gas sample, a liquid sample or a combination of both. The method comprises a first step in which the composition of a sample fed into the chromatograph is determined, i.e. the concentrations of its components, i.e. substances, are being measured. To that end, the chromatograph may comprise separating means like a separation column and a detector. In the course of the determination of the composition of the sample, the chromatograph generates chromatograms which reflect that composition. At least one of the chromatograms comprises a number of peaks, each peak in such a chromatogram reflecting the presence of a component of the sample. The number of peaks in the at least one chromatogram corresponds to the number of the substances in the sample. The number of peaks corresponds to the number of substances in the sample when the sample is only comprises specified substances. The substances are specified according to a preset specification. Such a preset specification may be determined beforehand, e.g. by a user of the twinned physical-digital system. The specified substances are the substances which are expected to be components of the sample or which plausibly could be components of the sample. Each peak of a specified substance is substantially located at a specified position in the chromatograms. The specification may comprise202400755 information, at where the positions of the specified substances are in the chromatograms. The position of the peaks of the specified substances reflect an elution time of the corresponding substance in the chromatograph. In other words, in such a state the sample may merely comprise substances which are desirable in context with the application for which the sample is used. In turn, an unspecified substance in the sample may be at least one of a contaminant, an impurity, a pollutant, a residue of an educt or a precursor, and a by-product. An unspecified substance may be any substance which is not expected in application in from which the sample is drawn. Thus, the number of peaks qualitatively reflects an intended composition of the sample or a nominal state of the sample.

[0018] In a second step of the disclosed method, a presence of at least one contaminant in the sample is detected. The presence of the at least one contaminant is detected when a peak is detected at an unspecified position in at least one chromatogram. To that end, chromatograms may be generated over and over when the chromatograph is operated, for example when further samples are fed into the chromatograph. When a chromatogram comprises a peak at an unspecified position, that peak is isolated. To that end, the at least one peak at the underspecified position is determined among the peaks in the corresponding chromatogram. Based on the functioning of the chromatograph, the peak at the unspecified position reflects a characteristic about what the unspecified substance that causes the peak at the unspecified position is or at least could be.

[0019] The disclosed method further comprises a third step Inlch a multiplicity of substances is selected from a database as potential contaminants. The substances encompassed by the multiplicity of substances constitute candidates, which could be the unspecified substance. The multiplicity of substances may be selected by a computer program product which implements the disclosed method. The database may be a library of virtual representations for substances. Each substance may be a different chemical element or a chemically distinct compound. Thus, for each of the substances of the selected multiplicity of substances, a virtual representation is provided. The virtual representations are fed into the digital twin. Based on that, a composition202400755 of a virtual sample is defined which may comprise the same substances as the sample, i.e. the physical sample as virtual representations, and additionally the virtual representation of at least one substance from the selected multiplicity of substances. In other terms, a virtual sample is generated for the digital twin which, in a virtual sense, comprises substances that are supposed to be part of the physical sample plus a potential unspecified substance.

[0020] In a fourth step of the discloses method, the digital twin of the chromatograph is run with virtual samples, each encompassing at least one virtual representations of a potential contaminant. The digital twin is run to generate corresponding virtual chromatograms. The digital twin may be run with multiple different virtual samples in a row, in a parallel manner or a combination of both. As a result of the fourth step, multiple virtual chromatograms are generated which are suitable to be further evaluated. In a fifth step of the disclosed method, the virtual chromatograms are compared to the at least one chromatogram that comprises the at least one peak at the unspecified position, which is caused by the unspecified substance. Degrees of membership between the at least one chromatogram with the at least one peak at the unspecified position and the virtual chromatograms is determined. The more similar a virtual chromatogram is to the chromatogram with the at least one peak at the unspecified position is, the more likely it is that the corresponding virtual chromatogram is based on the virtual representation of the unspecified substance present in the sample, i.e. the physical sample. During the fifth step, at least one virtual chromatogram is determined that shows at least a selectable minimum degree of membership between the chromatogram with the at least one peak at the unspecified position. The selectable minimum degree of membership may be defined by at least one coefficient or a relative quantity. For example, the virtual chromatogram with the highest degree of membership with the chromatogram may be determined or a selectable number of virtual chromatograms which show the highest degrees of membership. Thus, during the fifth step, the virtual chromatogram or virtual chromatograms most similar to the chromatogram from the chromatograph are determined. Furthermore, the substance that corresponds to the at least one determined virtual chromatogram is determined as the unspecified substance. In other terms, once the most similar virtual chromatogram or virtual chromatograms are determined, the corresponding unspecified substance or unspecified substances may be concluded. The disclosed202400755 method further comprises a sixth step in which the substance or substances determined in the fifth step is output to at least one of a user and a data interface.

[0021] The disclosed method may at least partially be embodied as a computer-implemented method. Moreover, the disclosed method allows for dealing with peaks at unspecified positions in a chromatogram which are not expected. Since a multiplicity of substances may be selected as potential unspecified substances, the disclosed method is configured to identify the present unspecified substance among a plethora of potential unspecified substances. The number of substances in the selected multiplicity may only be limited by the available computing resources which are utilized to perform the disclosed method. With increasing computing resources, the capabilities of the disclosed method may enhance by itself. Among others, the disclosed method is based on the surprising finding that virtual chromatograms may be generated and evaluated quickly enough to determine an unspecified substance with sufficient precision within a practical timeframe. Furthermore, the discloses method allows for automatically monitoring a composition of samples and at least supporting a user in identifying an occurring unspecified substance. As a consequence, the disclosed method may be utilized to monitor an operation of a chemical production system in which a chemical production process takes place. In turn, the disclosed method is configured to enhance the productivity of chemical production systems.

[0022] In an embodiment of the disclosed method, the digital twin of the chromatograph is being run with a selectable concentration of the virtual representation of at least one substance of the selected multiplicity of substances. Thus, the concentration of the virtual representation of substances which are potential unspecified substances may be varied in the digital twin. The fourth step of the disclosed method may be performed multiple times with a varied concentration of the virtual representation of at least one substance of the selected multiplicity. That allows for determining a concentration of the unspecified substance in the sample, i.e. the physical sample. Furthermore, the disclosed method may be configured to check the plausibility of a substance that is determined to be the unspecified substance. In many chemical production processes, byproducts or pollutants initially occur at low concentrations, for example when a porous catalyst202400755 becomes clogged, resulting in an unintended by-product. Furthermore, a steep increase of a concentration of an unspecified substance may indicate a sudden malfunction, for example when a valve unintentionally opens, and the underlying chemical production process is exposed to ambient air or is exposed to a reduced vessel pressure. Consequently, the disclosed method is configured to quantify the amount of the unspecified substance and to check if a corresponding fault scenario is commensurate with further information about the corresponding chemical product system. Based on a determined concentration of the unspecified substance, a level of confidence may be determined which characterizes how reliable an indication of the output unspecified substance is. Therefore, the disclosed method is configured to concisely indicate the state of a chemical production system.

[0023] In yet another embodiment of the disclosed method, the multiplicity of substances is selected through at least one of a statistical algorithm, a process model and a knowledge database. Such a statistical model may comprise statistical data about the underlying chemical product system or knowledge about a pertinent chemical reaction. The process model may comprise data about all substances used in the overall chemical production system. Based on such data, any substance may be ruled out as the unspecified substance which is not present in the chemical production system or which cannot be generated in the chemical production system. Such a process model may be stored in a control unit of the chemical production system and may be accessed through a suitable data interface, which may be an Application Programming Interface, also commonly referred to as an API. A knowledge database may comprise a record of at least one of previous cases of contamination, and previous maintenance activities. The record in the knowledge database may be based on data generated from the underlying chemical production system or at least similar chemical production systems. Based on at least one of the statistical algorithm, the process model and the knowledge database, the size of the multiplicity of substances selected in the third step may be reduced, resulting in reduced need for computing power. Thus, the disclosed method is configured to avoid computations of unrealistic potential unspecified substances. Furthermore, the virtual representations of the potential unspecified substances may be queued based on a likeliness which may be derived from at least one of the statistical algorithm, the process model and the knowledge database. Consequently, the disclosed202400755 method may be configured to yield realistic results quickly. In turn, the disclosed method is suitable for a rapid and concise indication of the unspecified in the sample, i.e. the physical sample. Particularly, the disclosed method combines the advantages of a simulation-based approach with the advantages of existing methods for identifying unspecified substances.

[0024] In the disclosed method, the degrees of membership between the chromatogram and the peak at the unspecified position and the virtual chromatograms are determined based on at least one of a comparison of the positions of the peak caused by the unspecified substance in the chromatogram and in the corresponding virtual chromatogram, and at least one geometric parameter that defines the shape of the peak caused by the unspecified substance in the chromatogram and the corresponding virtual chromatogram. The position of the peak caused by the unspecified substance in the chromatogram may be determined as an absolute position or a relative position, the relative position being defined in relation to a peak of a known component in the chromatogram, i.e. a peak of a specified substance. Since the position of the peak at the unspecified position is influenced by a retention effect of the separating means, the position of the peak at the unspecified position may be characteristic for the substance which it reflects. Furthermore, geometric parameters defining a shape of the peak caused by the unspecified substance may readily be determined. Such geometric parameters allow for a comprehensive, yet rapid characterization of the peak at the unspecified position, i.e. the peak caused by the unspecified substance. In turn, such a characterization allows for a comparison between the chromatogram and the corresponding virtual chromatogram. Both the comparison of the positions of the peak caused by the unspecified substance in the chromatogram and the corresponding virtual chromatogram and the at least one geometric parameter are continuous quantities, which allow for a quantified comparison. Therefore, the degree of membership between the chromatogram and the corresponding virtual chromatogram may be determined in a precise manner.

[0025] In a further embodiment of the disclosed method, the digital twin is configured to mirror the retention effect of a separating means of the chromatograph, for example a separation202400755 column. The digital twin may comprise a physics module that is configured to generate virtual representations of molecules of a substance and a virtual representation of a retention surface in the separating means. The digital twin may further be configured to simulate an interaction of the virtual representations of the molecules of the substance and the virtual representation of the retention surface, thus determining a virtual retention effect, which emulates a retention effect of the corresponding physical separating means on the substance in the chromatograph. To that end, the physics module may comprise data about physical-chemical properties of substances.

[0026] In yet another embodiment of the disclosed method, the method may comprise a seventh step in which the digital twin is run to mirror the operation of the chromatograph and to compare the at least one chromatogram to a corresponding virtual chromatogram. The virtual chromatogram is generated by the digital twin. The virtual chromatogram may define a reference peak which reflects which corresponding chromatogram is to be expected under idealized conditions of the chromatograph, for example in the absence of degradation and under perfectly constant ambient conditions. In an eighth step of the disclosed method, a deviation between at least one peak of the chromatogram and a corresponding peak in the virtual chromatogram is determined. Such a deviation may be determined based on at least one of the positions of the peaks in the chromatogram and the virtual chromatogram, and a geometric parameter defining the shape of the peaks in the chromatogram and the virtual chromatogram. In a ninth step of the disclosed method, at least one of an ambient parameter and an operating parameter of the digital twin is varied to match a virtual chromatogram to the corresponding chromatogram. The corresponding chromatogram may be the chromatogram employed in the seventh and eighth step. During the ninth step, at least one varied ambient parameter or a varied operating parameter of the digital twin is determined. In the ninth step, the digital twin is supplied with at least one of the at least one varied ambient parameter and the at least one varied operating parameter to recreate to corresponding chromatogram. When the virtual chromatogram generated based on at least one of at least one varied ambient parameter and at least one varied operating parameter matches the chromatogram, these variations may be taken account of. The varied ambient parameter may be an ambient temperature, an ambient air humidity, an ambient pressure or a202400755 composition of the ambient medium. The varied operating parameter may be a sample temperature, a sample pressure or a detector setting.

[0027] In a tenth step of the disclosed method, a type of at least one of the determined varied ambient parameter and the determined varied operating parameter are output to at least one of a user interface and the data interface. The type of the varied ambient parameter or the varied operating parameter may identify at least one of their physical unit and the corresponding virtual representation in the digital twin. Based on such an output, at least one of a user or an artificial intelligence may determine if the deviation between the virtual chromatogram generated during the seventh step and the chromatogram may be explained by changes of the ambient conditions or wear of the chromatograph. If that is not the case, the disclosed method may comprise that an error warning is output. Consequently, the disclosed method is configured to check the plausibility of a deviation between the chromatograph and the digital twin. Furthermore, the disclosed method may be configured to detect if a combination of types at least one varied ambient parameter and at least one varied operating parameter relates to a plausible deviation or not. Based on that, several kinds of deviations between the chromatograph and the digital twin may be determined to relate to errors in the chromatograph based with a reduced amount of computational steps.

[0028] Additionally, the disclosed method may comprise an eleventh step in which a value of at least one of the varied ambient parameter and the varied operating parameter are output to at least one of the user and the data interface. Outputting a value of at least one of the varied ambient parameter and the varied operating parameter allows for characterizing a root cause for the deviation between the peak in the chromatogram and the corresponding peak in the virtual chromatogram. Furthermore, the value of at least one of the varied ambient parameter and the varied operation parameter may be used as input for an artificial intelligence that may be utilized to determine the root cause of the deviation. Additionally, the disclosed method may comprise a twelfth step in which at least one of the varied ambient parameter and the varied operating parameter is compared to a predefined threshold and it is determined of the predefined threshold202400755 is exceeded. In a thirteenth step, a warning is output to at least one of the user and the data interface, the warning indicating a defective state of the chromatograph. The thirteenth step is performed if at least one of the varied ambient parameter and the varied operating parameter exceeds the predefined threshold. The threshold may be predefined by the user or an algorithm. Furthermore, the threshold may be set to delimit a value range of the corresponding ambient parameter or operating parameter that may be reached under realistic operating conditions with functioning components. If such a threshold is exceeded, that indicates that at least one component of the chromatograph is defective. So if the ambient parameters or the operating parameters of the digital twin cannot be realistically modified to imitate the current status of the chromatograph, that constitutes an indication for a defective state of the chromatograph. The digital twin may implement the concept of a virtual sensor for components of the chromatograph which are not connected to condition monitoring sensors.

[0029] In addition to that, a deteriorated component of the chromatograph may be determined based on the type of at least one of the varied ambient parameter and the varied operating parameter. Additionally or alternatively, the value of the corresponding varied ambient parameter or the corresponding the varied operating parameter may also be used to determine the deteriorated component of the chromatograph. That deteriorated component may be determined through an artificial intelligence connected to the digital twin. Deteriorations of certain components may look like changing ambient conditions or operating conditions. Thus, a pattern of apparently changing ambient parameter or operating parameters may be mapped to a deterioration of a specific component of the chromatograph. Consequently, the digital twin may also be used as a condition monitoring means for the chromatograph. Thus, the disclosed method enhances the possibilities for self-monitoring a chromatograph. To that end, the digital twin may be connected to a knowledge database.

[0030] The object described above is also achieved by a twinned physical-digital system which comprises a chromatograph and a digital twin of the chromatograph. The twinned physicaldigital system is configured to perform at least one of the embodiments of the method disclosed202400755 above. The digital twin may be connected to the chromatograph to receive sensor readings and detector readings the chromatograph uses. Additionally, the digital twin may be connected to the chromatograph to receive chromatograms generated by the chromatograph. Thus, the digital twin may be provided with all data that allows for mirroring a current status of the chromatograph. The features of the disclosed method also apply to the disclosed twinned physical-digital system accordingly.

[0031] Furthermore, the object described above is also achieved by the method for diagnosing a chromatograph as disclosed in the following. The chromatograph is a part of a twinned physicaldigital twin which also comprises a digital twin of the chromatograph that is diagnosed through the disclosed method. The disclosed method comprises a first step in which the chromatograph is operated which comprises that a sample is fed to the chromatograph. During the operation of the chromatograph, the composition of the sample is determined by the chromatograph. During the first step, at least one chromatogram is determined which reflects the composition of the sample fed to the chromatograph.

[0032] In a second step of the disclosed method, the digital twin is run to mirror the operation of the chromatograph. Mirroring the operation of the chromatograph comprises feeding a virtual representation of the sample to the digital twin of the chromatograph. When the digital twin is run, it generates a virtual chromatogram. During the second step at least one chromatogram is compared to the virtual chromatogram. In a nominal state of the chromatograph, the virtual chromatogram mirrors the corresponding chromatogram. The disclosed method also comprises a third step in which a deviation between the at least one peak in the chromatogram and a corresponding peak in the virtual chromatogram. Such a deviation may be an offset between the respective positions of the peaks in the chromatogram and the virtual chromatogram or a difference of their shapes.202400755

[0033] In a fourth step of the disclosed method at least one of an ambient parameter and an operating parameter of the digital twin is varied to match the virtual chromatogram to the corresponding chromatogram. The varied ambient parameter may be an ambient temperature, an ambient air humidity, an ambient pressure or a composition of the ambient medium. The varied operating parameter may be a sample temperature, a sample pressure or a detector setting. In addition to that, the at least one varied ambient parameter and the varied operating pressure of the digital twin is determined. In a subsequent fifth step, a type of the at least one of the varied ambient parameter and the varied operating parameter is output to at least one of a user and a data interface. The type of the varied ambient parameter or the varied operating parameter respectively may indicate at least one of its physical unit and the entity it is related to. Among others, the disclosed method is based on the finding that an apparently drifting ambient parameter or operating parameter may be characteristic of a defective or deteriorated component of the chromatograph. The discloses method may be embodied as a computer-implemented method.

[0034] Additionally, the disclosed method may comprise a sixth step in which a value of at least one of the varied ambient parameter and the varied operating parameter are output to at least one of the user and the data interface. Outputting a value of at least one of the varied ambient parameter and the varied operating parameter allows for characterizing a root cause for the deviation between the peak in the chromatogram and the corresponding peak in the virtual chromatogram. Furthermore, the value of at least one of the varied ambient parameter and the varied operation parameter may be used as input for an artificial intelligence that may be utilized to determine the root cause of the deviation. Additionally, the disclosed method may comprise a seventh step in which at least one of the varied ambient parameter and the varied operating parameter is compared to a predefined threshold and it is determined of the predefined threshold is exceeded. In a seventh step, a warning is output to at least one of the user and the data interface, the warning indicating a defective state of the chromatograph. The seventh step is performed if at least one of the varied ambient parameter and the varied operating parameter exceeds the predefined threshold. The threshold may be predefined by the user or an algorithm. Furthermore, the threshold may be set to delimit a value range of the corresponding ambient202400755 parameter or operating parameter that may be reached under realistic operating conditions with functioning components. If such a threshold is exceeded, that indicates that at least one component of the chromatograph is defective. So if the ambient parameters or the operating parameters of the digital twin cannot be realistically modified to imitate the current status of the chromatograph, that constitutes an indication for a defective state of the chromatograph. The digital twin may implement the concept of a virtual sensor for components of the chromatograph which are not connected to condition monitoring sensors.

[0035] In addition to that, a deteriorated component of the chromatograph may be determined based on the type of at least one of the varied ambient parameter and the varied operating parameter. Additionally or alternatively, the value of the corresponding varied ambient parameter or the corresponding the varied operating parameter may also be used to determine the deteriorated component of the chromatograph. That deteriorated component may be determined through an artificial intelligence connected to the digital twin. Deteriorations of certain components may look like changing ambient conditions or operating conditions. Thus, a pattern of apparently changing ambient parameter or operating parameters may be mapped to a deterioration of a specific component of the chromatograph. Consequently, the digital twin may also be used as a condition monitoring means for the chromatograph. Thus, the disclosed method enhances the possibilities for self-monitoring a chromatograph. To that end, the digital twin may be connected to a knowledge database.

[0036] The object described above is also achieved by a twinned physical-digital system which comprises a chromatograph and a digital twin of the chromatograph. The twinned physicaldigital system is configured to perform at least one of the embodiments of the method for diagnosing disclosed above. The digital twin may be connected to the chromatograph to receive sensor readings and detector reading the chromatograph uses. Additionally, the digital twin may be connected to the chromatograph to receive chromatograms generated by the chromatograph. Thus, the digital twin may be provided with all data that allows for mirroring a current status of202400755 the chromatograph. The features of the disclosed method also apply to the disclosed twinned physical-digital system accordingly.

[0037] The underlying object is also achieved by the disclosed computer program product. The computer program product is stored on a non-transitory medium and comprised program code that is configured to perform steps when loaded into a memory of a computer. These steps comprise a first step in which signals from a chromatograph are received. To that end, the disclosed computer program product may comprise a data interface that connects it to at least one detector comprised by the chromatograph. During the first step, chromatograms are generated based on the signals received from the chromatograph. Furthermore, a number of peaks is detected in at least one of the chromatograms, which reflects the number of substances in a sample that is analyzed by the chromatograph when the sample only comprises specified substances. The substances are specified according to a preset specification, which may be selected or defined by a user. Each peak caused by a specified substance is substantially located at a specified position in the chromatograms. The specified positions reflect an elution time of the respective substance. In such a state, the sample may merely comprise substances which are desirable in context with the application for which the sample is used. In turn, an unspecified substance in the sample may be at least one of a contaminant, an impurity, a pollutant, a residue of an educt or a precursor, and a by-product. The program code of the disclosed computer program product is further configured to perform a second step in which a presence of at least one unspecified substance in the sample is detected when a peak is detected at an unspecified position in at least one chromatogram. Still further, at least one peak at an unspecified position is isolated within the corresponding chromatogram. Isolating the peak at the unspecified position comprises identifying which peak has no counterpart among the specified substances. To that end, the computer program product may comprise a comparing algorithm for chromatograms.

[0038] The program code is further configured to perform a third step in which a multiplicity of substances is selected from a database as potential unspecified substances. The computer program product may comprise the database or may be connected to it. Virtual representations of202400755 substances from the selected multiplicity of substances are fed into a digital twin of the chromatograph. The multiplicity of substances may be selected through a knowledge database in which information about the pertaining chemical production process is stored. The program code is also configured to perform a fourth step in which the digital twin of the chromatograph is run with the virtual representations of substances from the selected multiplicity of substances. Thus, an operation of the chromatograph with samples comprising the potential unspecified substances is simulated. Based on that, virtual chromatograms are generated, the virtual chromatograms reflecting a result of the simulated operation of the chromatograph. To that end, the digital twin may comprise a model of a separating means of the chromatograph which may be configured to emulate a retention effect on the virtual representations of each substance in the sample, i.e. the virtual sample. The digital twin may be a component of the disclosed computer program product or a software component connected to the disclosed computer program product.

[0039] In a fifth step, that is also performed based on the program code of the disclosed computer program product, degrees of membership between the virtual chromatograms and a chromatogram that comprises the peak at the unspecified position are determined. The virtual chromatogram that shows the highest degrees of membership with the chromatogram with the at least one peak at the unspecified position may be assumed to comprise a virtual representation of a substance that is at least chemically similar to the unspecified substance is present in the sample, i.e. the physical sample. During the fifth step, at least one virtual chromatogram is determined that shows at least a selectable minimum degree of membership between the virtual chromatogram and the chromatogram with the at least one peak caused by the unspecified substance, i.e. the peak at the unspecified position. The selectable minimum degree of membership may be selected by a user or an algorithm, e.g. an artificial intelligence. The selectable minimum degree of membership may further be selected to identify all potential unspecified substances which could realistically be the unspecified substance present in the sample. The minimum selectable degree of membership may also be a relative criterion. For example, the one, two, three, etc. virtual chromatograms with the highest degrees of membership may be determined during the fifth step. In addition to that, the substance that corresponds to the at least one determined virtual chromatogram is identified as the unspecified substance in the202400755 sample. In a subsequent sixth step, the determined substance in the sixth step is output to at least one of a user and a data interface.[00401 Thus, the disclosed computer program product is configured to perform at least one of the embodiments of the method for operating a twinned physical-digital system as outlined above. Consequently, the features of the corresponding method also apply to the disclosed computer program products. The disclosed computer program may be embodied as a monolithic computer program product that is configured to be run on a single hardware platform. Alternatively, the disclosed computer program product may be embodied as a modular computer program product, comprising multiple software modules that are configured to run on separate hardware platforms and which interact with each other to provide the functionality outlined above. Such modular computer program products may be configured to be run on a computer cloud.

[0041] In an embodiment of the disclosed computer program product comprises at least one of the digital twin, the database and a data interface that is configured to connect the computer program product to the chromatograph. The data interface may be embodied as a so-called Application Programming Interface, also commonly known as an API.

[0042] The object described above is also achieved by a control unit that is configured for controlling an operation of a chromatograph. The control unit comprises a memory and a processor which are configured for running computer program products. The disclosed control unit further comprises a computer program that according to one of the embodiments described above. As a consequence, the features and advantages of the disclosed computer program product also apply to the disclosed control unit.

[0043] In addition to that, the object outlined above is also achieved by the disclosed method for operating a chemical production system which is configured to perform a chemical production process. The chemical production system comprises a first stage at which an intermediary product is produced. Furthermore, the chemical production system comprises a second stage at202400755 which the intermediary product is processed and a measurement stage between the first and second stage. The measurement stage is configured to determine a composition of the intermediary product which is transported from the first stage to the second stage. The measurement stage comprises a chromatograph which is utilized to determine the composition of a sample extracted from the intermediary product. The method for operating the chemical production system comprises a first step in which the composition of the sample is measured and corresponding chromatograms are generated. The chromatograms reflect the measured composition. The chromatograms comprise a number of peaks which corresponds to the number of substances in the sample when the sample only comprises specified substances according to a preset specification. The preset specification may be selected by a user. The preset specification comprises information about the positions of the peaks of each specified substance. The position of a peak of a specified substance reflects an elution time of that substance. In an orderly state of the underlying chemical production system, a peak of a specified substance will substantially be at the corresponding position given in the preset specification. In such a state, the sample merely comprises substances which are desirable in context with the chemical production process. In turn, an unspecified substance in the sample may be at least one of a contaminant, an impurity, a pollutant, a residue of an educt or a precursor, and a by-product.

[0044] In a second step of the disclosed method, a presence of at least one unspecified substance in the sample is detected. The presence of the at least one unspecified substance is detected when a peak is detected at an unspecified position in the chromatograms. An unspecified position is a position that is not defined in the preset specification. Alternatively, a peak may be at an unspecified position when its distance to the closest specified position exceeds a threshold distance. To that end, chromatograms may be generated over and over when the chromatograph is operated, for example when further samples are fed into the chromatograph. When a chromatogram comprises a peak at an unspecified position, that peak may be isolated. To that end, the at least one peak at the unspecified position is determined among the peaks in the corresponding chromatogram. Based on the functioning of the chromatograph, the peak at the unspecified position reflects a characteristic about what substance the corresponding unspecified substance is or at least could be.202400755

[0045] The disclosed method further comprises a third step in which a multiplicity of substances is selected from a database as potential contaminants. The substances encompassed by the multiplicity of substances constitute candidates, which could be the at least one unspecified substance. The multiplicity of substances may be selected by a computer program product which is utilized to implement the disclosed method. The database may be a library of virtual representations for substances. Each substance may be a different chemical element or a chemically distinct compound. Thus, for each of the substances of the selected multiplicity of substances, a virtual representation is provided. The virtual representations are fed into the digital twin. Based on that, a composition of a virtual sample is defined which may comprise the same substances as the sample, i.e. the physical sample as virtual representations, and additionally the virtual representation of at least one substance from the selected multiplicity of substances. In other terms, a virtual sample is generated for the digital twin which, in a virtual sense, comprises substances that are supposed to be part of the physical sample plus a potential unspecified substance.

[0046] In a fourth step of the discloses method, the digital twin of the chromatograph is run with virtual samples, each encompassing at least one virtual representations of a potential unspecified substance. The digital twin is run to generate corresponding virtual chromatograms. The digital twin may be run with multiple different virtual samples in a row, in a parallel manner or a combination of both. As a result of the fourth step, multiple virtual chromatograms are generated which are suitable to be further evaluated. In a fifth step of the disclosed method, the virtual chromatograms are compared to the at least one chromatogram that comprises the at least one additional peak. Degrees of membership between the at least one chromatogram with the at least one additional peak and the virtual chromatograms is determined. The more similar a virtual chromatogram is to the chromatogram with the at least one additional peak is, the more likely it is that the corresponding virtual chromatogram is based on the virtual representation of the unspecified substance present in the sample, i.e. the physical sample. During the fifth step, at least one virtual chromatogram is determined that shows a selectable minimum degree of membership between the chromatogram with the at least one additional peak. The selectable minimum degree of membership may be defined by at least one coefficient or a relative quantity.202400755For example, the virtual chromatogram with the highest degree of membership with the chromatogram may be determined or a selectable number of virtual chromatograms which show the highest degrees of membership. Thus, during the fifth step, the virtual chromatogram or virtual chromatograms most similar to the chromatogram from the chromatograph are determined. Furthermore, the substance that corresponds to the at least one determined virtual chromatogram is determined as the unspecified substance. In other terms, once the most similar virtual chromatogram or virtual chromatograms are determined, the corresponding unspecified substance or unspecified substances may be concluded. The disclosed method further comprises a sixth step in which the substance or substances determined as the contaminant in the fifth step is output to at least one of a knowledge database and an artificial intelligence algorithm. Furthermore, at least one of a root cause for the presence of the unspecified substance in the sample and a countermeasure to remove the unspecified substance from the chemical production process is determined. The root cause or the countermeasure respectively are determined through at least one of the artificial intelligence algorithm and the knowledge database. Knowledge databases and artificial intelligence algorithms may be configured to recognize root causes and corresponding countermeasures for imperfections in chemical production processes. Consequently, problems in the chemical production system may be detected and solved at an early stage. That allows for achieving an increased level of productivity in the chemical production system or the chemical production process respectively. The disclosed method for operating the chemical production system may implemented based on at least one embodiment of the method for operating a chromatograph disclosed above. Thus, each feature of the method for operating a chromatograph also applies to the disclosed method for operating a chemical production system

[0047] Moreover, the object outlined above is also achieved by the disclosed chemical production system. The chemical production system comprises a first stage at which an intermediary product is produced, and a second stage at which the intermediary product is processed. The chemical production system further comprises a measurement stage between the first and second stage of the chemical production system. The measurement stage comprises a chromatograph that is configured to measure a composition of a sample of the intermediary202400755 product. The sample may be extracted from the intermediary product. The chemical production system is configured to perform a method for operating a chemical production system as described above. Particularly, the chemical production system may comprise a control unit according to one of the embodiments described above.

[0048] Now, turning to the figures, the present disclosure is explained based on single embodiments. The figures are to be construed to supplement each other. Particularly, identical numerals are to be construed to have the same technological meaning. Single features from different embodiments may also be combined.

[0049] FIG 1 shows an embodiment of the disclosed method 1000 for operating a twinned physical-digital system 10 during a first stage. The twinned physical-digital system 10 comprises a chromatograph 12 that is configured to determine a composition 16 of a sample 15, which comprises a first, a second and a third substance 17, 18, 19. The chromatograph 12 comprises valves 11 which are configured to let the sample 15 in and out of the chromatograph.Furthermore, the chromatograph 12 comprises separating means 13 which are separation columns. A modulator 31 is arranged between the separating means 13, which allows for so- called GC-by-GC chromatography. Still further, the comprises a detector 14. Based on readings from the detector 14, chromatograms 30 of the sample 15 are generated during the disclosed method 1000. To that end, the chromatograph 12 comprises an evaluation unit 35 that is connected to the detector 14. The chromatograph 12 and its components basically constitutes the physical portion of the underlying twinned physical-digital system 10.

[0050] In addition to that, the twinned physical-digital system 10 comprises a digital twin 20 of the chromatograph 12. The digital twin 20 basically constitutes a virtual chromatograph that is configured to mirror an operational behavior of the chromatograph 12. The digital twin 20 comprises virtual representations of components of the chromatograph 12, for example virtual valves 21, virtual separating means 23, a virtual modulator 41, a virtual detector 24 and a virtual202400755 evaluation unit 45. The digital twin 20 is configured to take a virtual sample 25 in, which comprises virtual representations 27, 28, 29 of the first, second and third substance 17, 18, 19. Consequently, the virtual sample 25 also has a composition 16. The feeding of the digital twin 20 with the virtual sample 25 is symbolized by arrow 21. With it virtual components, the digital twin 20 is configured to generate virtual chromatograms 40 which reflect the composition 16 of the virtual sample 25 that is fed into the digital twin 20.

[0051] Both the chromatograms 30 and the virtual chromatograms 40 comprise a time axis 32 and an intensity axis 33. In each chromatogram 30 and each virtual chromatogram 40, peaks 34 or virtual peaks 49 are positioned along the time axis 32, their positioning indicating a retention effect of at least one of the separating means 13 or the virtual separating means 23 on one of the substances 17, 18, 19 or the virtual representations 27, 28, 29 of substances in the sample 15 or the virtual sample 25, respectively. A height of a peak 34 or a virtual peak 49 along the intensity axis 33 shows a concentration of the corresponding substance 17, 18, 19 or the corresponding virtual representation 27, 28, 29 of a substance in the sample 15 or the virtual sample 25, respectively.

[0052] The disclosed method 1000 comprises a first step 1010 in which the twinned physicaldigital system 10 is operated and the sample 15 is fed into the chromatograph 12. The sample 15 may be continuously fed into the chromatograph 12. Furthermore, chromatograms 30 are generated during the first step 1010, which reflect the composition 16 of the sample 15.Correspondingly, the chromatograms 30 may be continuously generated which is symbolized by the reverting arrow 39 in FIG 1. At least one of the chromatograms 30 generated during the first step 1010 comprises a number of peaks 34 which corresponds to the number of substances 17, 18, 19 in the sample 15 when the sample 15 is uncontaminated. In the embodiment according to FIG 1, the sample 15 is supposed to comprise three different substances 17, 18, 19. Thus, a chromatogram 30 with an uncontaminated sample 15 comprises three different peaks 34. The composition 16 of the sample 15 only with the three substances 17, 18, 19 is given in a preset specification. In turn that defines the positions of the peaks 34 caused by the three substances 17,20240075518, 19 in a chromatogram 30. The substances 17, 18, 19 in the sample 15 are desirable substances in the present case.

[0053] In a second step 1020 of the disclosed method 1000, a presence of a least one unspecified substance 37 in the sample 15 is detected when a peak 36 is detected at an unspecified position among the detected peaks 34 in at least one chromatogram 30. The position of the peaks 34, 36 is to be understood to be a position along the horizontal axis of the chromatogram 30. The chromatogram 30 according to FIG 1 shows a peak 36 at an unspecified position which is caused by the unspecified substance 37 in the sample 15. The term “unspecified sample” is to be construed to relate to any substance that is not given in the preset specification. In the sense of the disclosed method 1000, unspecified substance 37 may be at least one of a contaminant, an impurity, a pollutant, a residue of an educt or a precursor, and a by-product. The disclosed method 1000 is further configured to determine which substance the unspecified substance 37 is. To that end, the peak 36 at the unspecified position is isolated the remaining peaks 34. When the peak 36 at the unspecified position is isolated, that unspecified position constitutes a characteristic of what the unspecified substance 37 is or at least may be. A chromatogram 30 with a peak 36 at the unspecified position may be compared to a previous chromatogram 30. The first and second step 1010, 1020 of the disclosed method 1000 are implemented through a computer-program product 80.

[0054] The disclosed method 1000 also comprises further steps 1030, 1040, 1050, 1060 which are performed during a second stage of the disclosed method 1000 as shown in FIG 2. Particularly, the disclosed method 1000 comprises a third step 1030 in which a multiplicity of substances is selected from database 46. For each substance there is a corresponding virtual representation 44. Each virtual representation 44 of a substance reflects a potential unspecified substance 43 of the sample 15. The selection 47 from the database 46 is symbolized by a arrows. The selection 47 may be performed based on an artificial intelligence 48 which is configured to select the potential contaminants, i.e. the corresponding virtual representations 44. The selected virtual representations 44 are fed into contaminated virtual samples 42 which comprise at least202400755 one of the selected virtual representations 44 of a substance as a potential unspecified substance 43. Such virtual samples with virtual representations 44 of at least one potential unspecified substance may be referred to as contaminated virtual samples 42. The contaminated virtual samples 42 with the potential unspecified substances 43, i.e. their virtual representation, are generated systematically by adding at least one potential unspecified substance 43, i.e. its virtual representation 43, to a virtual sample 15 that initially consists of the virtual representations 27, 28, 29 of the desirable substances 17, 18, 19. That systematic generation is follows the selection 47 of the substances 44. In the course of the third step 1030, the contaminated virtual samples 42 are fed into the digital twin 20. The contaminated virtual samples 42 may be subsequently fed into the digital twin 20 or in parallel.

[0055] In a fourth step 1040 of the disclosed method 1000, the digital twin 20 of the chromatograph 12 is run with the virtual representations 44 of potential unspecified substances 43, i.e. with the contaminated virtual samples 42. When the digital twin 20 is run, the interaction between the potential unspecified substances 43 with the chromatograph 12 is simulated. Based on that, virtual chromatograms 40 are generated. In their structure, the virtual chromatograms 40 correspond to chromatograms 30 with a time-axis 32 and an intensity axis 33. The virtual chromatograms 40 comprise virtual peaks 49 which correspond virtual representations 27, 28, 29 of the first, second and third substance 17, 18, 19 of the sample 15. In addition to that, each virtual chromatogram 40 comprises a virtual peak 49 that corresponds to a potential unspecified substance 43, i.e. to its virtual representation 44.

[0056] The disclosed method 1000 also comprises a fifth step 1050 during which degrees of membership between the virtual chromatograms 40 and a chromatogram 30 is determined. The chromatogram 30 is generated during the second step 1020 of the disclosed method 1000 and comprises the peak 36 at the unspecified position, which is caused by the unspecified substance 37. In order to determine the degree of membership between the virtual chromatograms 40 and the chromatogram 30, they are compared with each other. The virtual chromatogram 40 that shows a selectable minimum degree of membership between the peak 36 at the unspecified202400755 position and the corresponding virtual peak 49 caused by a virtual representation 44 of a potential unspecified substance 43 is determined. The determined virtual chromatogram 40 is concluded to comprise the virtual representation 44 of a substance that actually corresponds to the unspecified substance 37 in the sample 15. Since the type, i.e. chemical description, of each potential unspecified substance 43 is known from the database 46, the type of the potential contaminant 43 in the determined virtual chromatogram 40 is determined to be the unspecified substance 37 of the sample 15. The selectable degree of membership between the chromatogram 30 and the virtual chromatograms 40 may be any mathematical expression that allows for quantifying similarities between the virtual chromatograms 40 and the chromatogram 30 or between individual peaks 34 and virtual peaks 49. For example, the virtual chromatogram 40 that shows the highest degree of similarity with the chromatogram 30 with the peak 36 at the unspecified position may be determined to reflect the sample 15 with the unspecified substance 37.

[0057] In a subsequent sixth step 1060 of the disclosed method 1000, the determined potential unspecified substance 43, which corresponds to the unspecified substance 37, is output to a user interface 22 and a data interface 26. Consequently, the sixth step 1060 outputs the result of the previous steps 1010, 1020, 1030, 1040, 1050 and indicates which substance is currently contaminating the sample 15. The steps 1030, 1040, 1050, 1060 may at least partially be implemented through the computer program product 80 outlined above. The computer-program product 80 may comprise the digital twin 20 of the chromatograph 12 and may be configured to generate the virtual chromatograms 40 based on virtual contaminated samples 42 provided based on the selection 47 from the database 46. Thus, the disclosed method 1000 may be a computer- implemented method.

[0058] FIG 3 schematically shows the fifth step 1050 of the disclosed method 1000 in more detail. Particularly, FIG 3 shows the chromatogram 30 from the chromatograph 12, as shown for example in FIG 1 and FIG 2. The chromatogram 30 comprises both a time-axis 32 and an intensity axis 33 and shows peaks 34 for each substance 17, 18, 19 of the sample 15 and the peak 36 at the unspecified position for the unspecified substance 37. Furthermore, FIG 3 shows a corresponding virtual chromatogram 40 which also comprises a time-axis 32 and an intensity202400755 axis 33. In FIG 3, the time axes 32 and intensity axes 33 have the substantially same scale. The virtual chromatogram 40 comprises virtual peaks 49 which are derived from a contaminated virtual sample 42. The virtual peaks 49 correspond to virtual representations 27, 28, 29 of the first, second and third substance 17, 18, 19 of the sample and substantially match the corresponding peaks 34 in the chromatogram 30. In addition to that, the virtual chromatogram 40 also comprises a virtual peak 49 that is derived from a substance 44 which is added to the virtual sample 25 to form the contaminated virtual sample 42, as shown in FIG 2. The peaks 34 of the first, second and third substance 17, 18, 19 and their corresponding virtual peaks 49 match insofar that they have substantially identical or similar absolute positions 51 along the time-axis 32. The absolute positions 51 of the substances 17, 18, 19 may be defined in a preset specification. Matching absolute positions 51 of the peaks 34 and the corresponding virtual peaks 49 may be an indication that the retention effect of the separating means 13 is well mirrored by the virtual separating means 23 in the digital twin 20, as shown in FIG 1. In turn, the relative positions 52 of the peaks 34 and the corresponding virtual peaks 49 also substantially match. The relative positions 52 of the substances 17, 18, 19 may also be defined in the preset specification.

[0059] During the fifth step 1050 the peak 36 at the unspecified position and the virtual peak 49 caused by the selected substance 44 are compared. That comparison may encompass that the absolute positions 51 of the peak 36 at the unspecified position and the corresponding virtual peak 49 caused by the selected substance 44 are compared. Alternatively or additionally, the relative positions 52 of the peak 36 at the unspecified position and the corresponding virtual peak 49 may be compared. With the virtual peaks 49 corresponding to the virtual representations 27, 28, 29 of the first, second and third substance 17, 18, 19 of the sample 15 match their counterparts in the chromatogram 30, i.e. the peaks 34, one may assume or conclude that the retention effect of the separating means 13 is simulated in an exact manner. Since retention effects are usually specific to each substance, one may assume that the virtual peak 49 of the substance 44 selected in the virtual chromatogram 42 will substantially match the peak 36 at the unspecified position in terms of absolute position 51 and relative position 52 along the time-axes 32 of the chromatogram 30 and the virtual chromatogram 42. During the fifth step 1050, a difference in terms of at least one of absolute position 51 and relative position 52 between the202400755 peak 36 at the unspecified position and the virtual peak 49 caused by the selected substance 44 may be determined. Such a difference describes a degree of membership between the chromatogram 30 and the virtual chromatogram 40. Furthermore, such a difference may be compared to a threshold value which constitutes a selectable minimum degree of membership. With multiple virtual chromatograms 40 involved, the selectable minimum degree of membership may also be a relative criterion. As an example, the virtual chromatogram 40 with the highest degree of membership when compared to the chromatogram 30 may be determined to reflect the unspecified substance 37.

[0060] In addition to that, geometric parameters of the additional peak 36 and the corresponding virtual peak 49 caused by the selected substance 44 may be derived from the chromatogram 30 and the virtual chromatogram 40, respectively, to determine if the degree of membership between them. Such a geometric parameter may be a width 55 of the peak 36 at the unspecified position which is compared to the width 55 of the corresponding virtual peak 49. Another geometric parameter may be a height 53 of the additional peak 36 and the corresponding virtual peak 49. Both the width 55 of the peak 36 at the unspecified position and its corresponding virtual peak 49 may be determined by the concentration of the unspecified position 37 and the selected substance 44, respectively. In many cases caused by continuous mechanisms like wear and degradation, unspecified substances 37 initially occur in low concentrations. In contrast to that, in many cases caused by abrupt causes, like in a defunct component of the chromatograph 12, unspecified substances 37 may initially occur in high concentrations. During the fifth step 1050, the concentration of the selected substance 44 may be selected, thus updating the virtual chromatogram 40 to match the additional peak 36 in terms of width 55 and height 53. Thus, also the concentration of the unspecified substance 37 in the sample 15 may also be determined during the disclosed method 1000. In addition to that, the disclosed method 1000 may also be utilized to determine if the unspecified substance 37 has been caused by a continuous mechanism like wear or degradation, or an abrupt mechanism like failure of a component of the chromatograph 12. The geometric parameters, the absolute positions 51 and the relative positions 52 described above may be applied in any conceivable combination to determine at least the202400755 unspecified substance 37. The fifth step 1050 is performed based on a computer-program product 80. As a consequence, the disclosed method 1000 is a computer-implemented method.

[0061] FIG 4 shows an embodiment of the disclosed method 2000 for diagnosing a chromatograph 12. The method 2000 for diagnosing may be incorporated into the disclosed method 1000 for operating a twinned physical-digital system 10. Thus, the steps 2010, 2020, 2030, 2040, 2050, of the disclosed method 2000 for diagnosing a chromatograph 12 may also be construed to constitute steps 1070, 1080, 1080, 1090, 1100 of the disclosed method 1000 for operating the twinned physical-digital system 10. FIG 4 shows the disclosed method 2000 for diagnosing a chromatograph 12 during a first stage.

[0062] The chromatograph 12 is part of a twinned physical-digital system 10 and is configured to determine a composition 16 of a sample 15, which comprises a first, a second and a third substance 17, 18, 19. The chromatograph 12 comprises valves 11 which are configured to let the sample 15 in and out of the chromatograph 12. Furthermore, the chromatograph 12 comprises separating means 13 which are separation columns. A modulator 31 is arranged between the separating means 13, which allows for so-called GC-by-GC chromatography. Still further, the comprises a detector 14. Based on readings from the detector 14, chromatograms 30 of the sample 15 are generated during the disclosed method 1000. The chromatograms 30 may be generated continuously during an operation of the chromatograph 12, which is symbolized by the reverting arrow 39. To that end, the chromatograph 12 comprises an evaluation unit 35 that is connected to the detector 14. The chromatograph 12 and its components basically constitutes the physical portion of the underlying twinned physical-digital system 10.

[0063] In addition to that, the twinned physical-digital system 10 comprises a digital twin 20 of the chromatograph 12. The digital twin 20 basically constitutes a virtual chromatograph that is configured to mirror an operational behavior of the chromatograph 12. The digital twin 20 comprises virtual representations of components of the chromatograph 12, for example virtual202400755 valves 21, virtual separating means 23, a virtual modulator 41, a virtual detector 24 and a virtual evaluation unit 45. The digital twin 20 is configured to take a virtual sample 25 in, which comprises virtual representations 27, 28, 29 of the first, second and third substance 17, 18, 19. Consequently, the virtual sample 25 also has a composition 16. The feeding of the digital twin 20 with the virtual sample 25 is symbolized by arrow 21. With its virtual components, the digital twin 20 is configured to generate virtual chromatograms 40 which reflect the composition 16 of the virtual sample 25 that is fed into the digital twin 20.

[0064] Both the chromatograms 30 and the virtual chromatograms 40 comprise a time axis 32 and an intensity axis 33. In each chromatogram 30 and each virtual chromatogram 40, peaks 34 or virtual peaks 49 are positioned along the time axis 32, their positioning indicating a retention effect of at least one of the separating means 13 or the virtual separating means 23 on one of the substances 17, 18, 19 or the virtual representations 27, 28, 29 of substances in the sample 15 or the virtual sample 25, respectively. A height of a peak 34 or a virtual peak 49 along the intensity axis 33 shows a concentration of the corresponding substance 17, 18, 19 or the corresponding virtual representation 27, 28, 29 of a substance in the sample 15 or the virtual sample 25, respectively.

[0065] During a first step 2010 of the disclosed method 2000 for diagnosing the chromatograph 12, the sample 15 is fed into the chromatograph 12 and the chromatograph 12 is operated. When the chromatograph 12 is operated, at least one chromatogram 30 is determined which reflects the composition 16 of the sample 15. In a subsequent second step 2010 of the method 2000 for diagnosing the chromatograph 12, the digital twin 20 is run to mirror the operation of the chromatograph 12. The first and second step 2010, 2020 may be performed simultaneously. When the digital twin 20 is run, at least one virtual chromatogram 40 is generated that corresponds to the at least one chromatogram 30 generated in the first step 2010. When a current state of the chromatograph 12 matches the state modeled in the digital twin 20, the chromatograph 12 and the digital twin 20 work in lockstep, i.e. mirroring each other.202400755

[0066] In a third step 2030 of the disclosed method 2000 for diagnosing the chromatograph 12, a deviation between at least one peak 34 in the chromatogram 12 and at corresponding peak, i.e. a virtual peak 49, in the virtual chromatogram 40 is detected and determined. In the example shown in FIG 4, the peak 34 that reflects the second substance 18 of the sample 15 deviates from the virtual peak 49 that reflects the virtual representation 28 of the second substance 18 in the virtual sample 40. Particularly, the peak 34 in the chromatogram 30 and the corresponding virtual peak 49 in the virtual chromatogram 40 show different intensities. In order to determine the deviation between the at least one peak 34 in the chromatogram 30 and the corresponding virtual peak 49, any conceivable geometric parameter may be applied which characterizes the peak 34 and the corresponding virtual peak 49. The detected deviation between the chromatograph 30 and the virtual chromatograph 40 indicated that a failure in the chromatograph 12 is imminent or has already occurred. The steps 2010, 2020, 2030 are performed based on a computer-program product 80, which may also implement the disclosed method 1000 for operating the twinned physical-digital system 10. Consequently, the disclosed method 2000 for diagnosing the chromatograph 12 is embodied as a computer-implemented method.

[0067] A second stage of the disclosed method 2000 for diagnosing the chromatograph 12 is schematically shown in FIG 5. The second stage substantially follows the first stage depicted in FIG 4. The digital twin 20 is configured to take into account ambient parameters 57 and operating parameters 59 which influence the operation of the digital twin 20. As long as the chromatogram 30 and the virtual chromatograph 12 are in lockstep with each other, i.e. as long as there is no deviation between them, the ambient parameters 57 and the operating parameters 59 are selected to match the ambient parameters and operating parameters of the chromatograph 12. The ambient parameters 47 and the operating parameters 59 form sets 56, 58, respectively.

[0068] The disclosed method 2000 for diagnosing the chromatograph 12 comprises a fourth step 2040 during which at least one of an ambient parameter 57 and an operating parameter 59 are varied. When the at least one of the ambient parameter 57 and the operating parameter 59 are varied, they deviate from the latest known corresponding ambient parameter or corresponding202400755 operating parameter 59 of the chromatograph 12. Furthermore, the virtual sample 25 applied during the fourth step 2040 may have the same composition 16 as the sample 15 as shown on a chromatogram 30 generated prior to the detection of the deviation. Thus, the virtual representations 27, 28, 29 of the first, second and third substance 17, 18, 19 match the last known sample 15. The at least one of the ambient parameter 57 and the operating parameter 59 may be varied based on an artificial intelligence 60. The variation of the at least one of the ambient parameter 57 and the operating parameter 59 in symbolized by the double arrow 62. The virtual sample 25 as shown in FIG 5 is fed into the digital twin 20 combined with at least one of a set 56 of ambient parameters 57 and a set 58 of operating parameters 59, at least one of them comprising at least one varied ambient parameter 57 and a varied operating parameter 59 respectively. When the digital twin 20 is run, virtual chromatograms 40 are generated. Due to the at least one varied ambient parameter 57 and the varied operating parameter 59, the virtual peak 49 that reflects the virtual representation 28 of the second substance 18, assumes a different shape. The at least one of the ambient parameter 57 and the operating parameter 59 are varied until one of the virtual chromatograms 49 substantially matches the chromatogram 30 which comprises the deviation detected during the third step 2030. In other terms, at least one ambient parameter 57, at least one operating parameter, or a combination of such, is varied as input for the digital twin 20 it matches the chromatogram 30 from the chromatograph 12 which shows the identified deviation. The fourth step 2040 of the disclosed method 2000 for diagnosing the chromatograph 12 may correspond to a ninth step 1090 of the disclosed method 1000 for operating the twinned physical-digital system 10.

[0069] In a subsequent fifth step 2050 of the disclosed method 2000 for diagnosing the chromatograph 12 a type of at least one of the varied ambient parameter 57 and the varied operating parameter 59 is output to at least one of a user through a user interface 22 and a data interface 26. The type identifies to which quantity or setting the varied ambient parameter 57 or the varied operating parameter 59 respectively relates. The fifth step 2050 of the disclosed method 2000 for diagnosing the chromatograph 12 may be implemented as a tenth step 1100 of the disclosed method 1000 for operating the twinned physical-digital system 10. In addition to that, a sixth step 2060 is performed in which a value of the at least one of the varied ambient202400755 parameter 57 and the varied operating parameter 59 is output to at least one of a user through the user interface 22 and a data interface 26. Tn combination with the type of the varied ambient parameter or varied operating parameter respectively, a more detailed assessment of the state of the chromatograph 12 is possible. Based on at least one of the type and the value of the varied ambient parameter 57 or varied operating parameter 59 respectively, a root cause for the deviation may be determined. A knowledge database not shown in more detail in FIG 5 may be utilized to determine such a root cause, for example a failure of a specific component of the chromatograph. For example, an apparent drop of an process pressure or an ambient pressure may be caused by a deteriorating seal in the chromatograph 12. In addition to that, the value of the varied ambient parameter or the varied operating parameter respectively may be an indication if the apparent changes to the chromatograph 12 are realistic. An excessive change of at least one of these parameters may be an indication that such a change is not realistic and that the root cause has to be a sudden failure of a component of the chromatograph 12. The sixth step 2060 of the disclosed method 2000 for diagnosing the chromatograph 12 may be implemented as an eleventh step 1110 of the disclosed method 1000 for operating the twinned physical-digital system 10.

[0070] Moreover, the disclose method 2000 for diagnosing the chromatograph 12 may comprise a seventh step 2070 during which at least one of the varied ambient parameter 57 and the varied operating parameter 59 are compared to a predefined threshold 61. If at least one of the varied ambient parameter 57 and the varied operating parameter 59 exceeds the predefined threshold 61, a defective state of the chromatograph 12 is detected in an eighth step 2080 of the disclosed method 2000 for diagnosing the chromatograph 12. The threshold may be predefined by a user, an algorithm or an artificial intelligence. The threshold may be predefined high enough to avoid false indications of defective states of the chromatograph 12, depending on the underlying application of the chromatograph 12, e.g. a chemical production process. In addition to that, a warning is output during the eighth step 2080 of the disclosed method 2000 for diagnosing the chromatograph 12. The warning is output to at least one of the user through the user interface 22 and the data interface 26. The seventh and eighth step 2070, 2080 of the disclosed method 2000 for diagnosing the chromatograph 12 may be implemented as a twelfth and a thirteenth step2024007551120, 1130 of the disclosed method 1000 for operating the twinned physical-digital system 10. The steps 2040,2050, 2060, 2070, 2080 outlined above may be implemented through a computer-program product 80. Thus, the disclosed method 2000 for diagnosing the chromatograph 12 is a computer-implemented method.

[0071] FIG 6 shows an embodiment of the disclosed method 3000 for operating a chemical production system 70 which comprises a first stage 72. An intermediary product 75 is produced at the first stage 72, the production of the intermediary product 75 being a part of a chemical production process that is performed by the chemical production system 70. The chemical production system 70 further comprises a second stage 74 to which the intermediary product 75 is transported. The intermediary product 75 may be transported through pipes, via a conveyor belt or any other conveying means and may be further processed at the second stage 74. A measurement stage 76 is arranged between the first stage 72 and the second stage 74, where a sample 15 of the intermediary product 75 is analyzed. The measurement stage 76 is equipped with a chromatograph 12, that is part of a twinned physical-digital system 10. The twinned physical-digital system 10 further comprises a digital twin 20 of the chromatograph 12. The twinned physical-digital system 20 may be embodied according to any of the embodiments outlined above. With the twinned physical-digital system 10, the intermediary stage 76 is configured to determine a composition 16 of the sample 15.

[0072] The chemical production system 70 is configured to be operated through the method 3000 which comprises a first step 3010 in which the sample 15 is fed into the chromatograph 12 and the composition of the sample 15 is determined. At least one of the chromatograms 30 generated during the first step 3010 comprises a first number of peaks 34 which corresponds to the number of substances 17, 18, 19 in the sample 15 when the sample 15 is uncontaminated, i.e. the sample 15 complies with a preset specification. In the embodiment according to FIG 4, the sample 15 is supposed to comprise three different substances 17, 18, 19. Thus, a chromatogram 30 with an uncontaminated sample 15 comprises three different peaks 34.202400755

[0073] In a second step 3020 of the disclosed method 3000, a presence of a least one contaminant 37 in the sample 15 is detected when a peak 36 at an unspecified position is detected among the peaks 34, 36 in at least one chromatogram 30. The chromatogram 30 according to FIG 4 shows a peak 36 at an unspecified position which is caused by the unspecified substance 37 in the sample 15. In the sense of the disclosed method 3000, the unspecified substance 37 may be at least one of a contaminant, an impurity, a pollutant, a residue of an educt or a precursor, and a by-product. In other terms, the unspecified substance 37 may be any substance that is not given in the preset specification. The disclosed method 3000 is further configured to determine which substance the unspecified substance 37 is. To that end, the peak 36 at the unspecified position is isolated from the remaining peaks 34. A chromatogram 30 with a peak 36 at an unspecified position may be compared to a previous chromatogram 30. The first and second step 3010, 3020 of the disclosed method 3000 are implemented through a computerprogram product 80.

[0074] The disclosed method 3000 also comprises further steps 3030, 3040, 3050, 3060. Particularly, the disclosed method 3000 comprises a third step 3030 in which a multiplicity of substances is selected from database 46. Virtual representations 44, as for example shown in FIG 2, of the selected substances are fed into the digital twin 20 of the chromatograph 12. In a fourth step 3040 of the disclosed method 3000, the digital twin 20 of the chromatograph 12 is run with the virtual representations 44 the selected substances, which are potential unspecified substances43. When the digital twin 20 is run, the interaction between the potential unspecified substances 43 with the chromatograph 12 is simulated. Based on that, virtual chromatograms 40 are generated. In their structure, the virtual chromatograms 40 correspond to chromatograms 30 with a time-axis 32 and an intensity axis 33. The virtual chromatograms 40 comprise virtual peaks 49 which correspond virtual representations 27, 28, 29 of the first, second and third substance 17, 18, 19 of the sample 15. In addition to that, each virtual chromatogram 40 comprises a virtual peak 49 that corresponds to a potential unspecified substance 43, i.e. to its virtual representation44.202400755

[0075] The disclosed method 3000 also comprises a fifth step 3050 during which degrees of membership between the virtual chromatograms 40 and a chromatogram 30 is determined. The chromatogram 30 is generated during the second step 3020 of the disclosed method 3000 and comprises the peak 36 at the unspecified position, which is caused by the unspecified substance 37. In order to determine the degree of membership between the virtual chromatograms 40 and the chromatogram 30, they are compared with each other. The virtual chromatogram 40 that shows a selectable minimum degree of membership between the peak 36 at the unspecified position and the corresponding virtual peak 49 caused by a virtual representation 44 of a potential unspecified substance 43 is determined. The determined virtual chromatogram 40 is concluded to comprise the virtual representation 44 of a substance that actually corresponds to the unspecified substance 37 in the sample 15. Since the type, i.e. chemical description, of each potential unspecified substance 43 is known from the database 46, the type of the potential unspecified substance 43 in the determined virtual chromatogram 40 is determined to be the unspecified substance 37 of the sample 15. The selectable degree of membership between the chromatogram 30 and the virtual chromatograms 40 may be any mathematical expression that allows for quantifying similarities between the virtual chromatograms 40 and the chromatogram 30 or between individual peaks 34 and virtual peaks 49. For example, the virtual chromatogram 40 that shows the highest degree of similarity with the chromatogram 30 with the peak 36 at the unspecified position may be determined to reflect the sample 15 with the unspecified substance 37.

[0076] In a subsequent sixth step 3060 of the disclosed method 3000, the determined potential unspecified substance 43, which corresponds to the unspecified substance 37, is output to a knowledge database and an artificial intelligence algorithm 82. This determined unspecified substance 37, that is its type, which may be a chemical designation, is output to the knowledge database 60 and the artificial intelligence algorithm 82 through a data interface 26. The knowledge database 60 and the artificial intelligence 82 are run on a control unit 85 that is configured to control at least the first stage 72 of the chemical production system 70. During the sixth step 3060, the knowledge database 60 and the artificial intelligence 82 are utilized to determine at least one of a root cause for the presence of the unspecified substance 37 in the202400755 sample 15 and a countermeasure to remove the unspecified substance 37 from the chemical production process. When a countermeasure is determined, the control unit 85 may send commands 86 to at least the first stage 72 of the chemical production system 70 to implement the determined countermeasure.

[0077] The steps 3010, 3020, 3030, 3040, 3050, 3050 may be performed corresponding to the steps 1010, 1020, 1030, 1040, 1050, 1060 of the method for operating a twinned physical-digital system 10 described above. The features of the method 1000 for operating the twinned physicaldigital system 10 and the features of the twinned physical-digital system 10 also apply to the shown method 3000 for operating the chemical production system 70. Moreover, the computerprogram product 80 may comprise the digital twin 20 of the chromatograph 12 and may by configured to generate the virtual chromatograms. Thus, the disclosed method 3000 may be a computer-implemented method.

Claims

202400755CLAIMS1. A method for operating a twinned physical-digital system, the twinned physicaldigital system comprising a chromatograph and a digital twin of the chromatograph, the method comprising:Determining a composition of a sample fed into the chromatograph and generating chromatograms which reflect the measured composition, at least one of the chromatograms comprising a number of peaks which corresponds to the number of substances in the sample when the sample only comprises specified substances according to a preset specification, each of the peaks being substantially at a specified position in the chromatograms;Detecting a presence of at least one unspecified substance in the sample when a peak is detected at an unspecified position in at least one chromatogram;Selecting a multiplicity of substances from a database as potential unspecified substances and feeding virtual representations of substances from the selected multiplicity of substances into the digital twin;Running the digital twin of the chromatograph with the virtual representations and generating virtual chromatograms;Determining degrees of membership between the virtual chromatograms and the chromatogram that comprises the peak at the unspecified position, determining at least one virtual chromatogram that shows at least a selectable minimum degree of membership and determining the substance that corresponds to the at least one determined virtual chromatogram as the unspecified substance;Outputting the determined substance to at least one of a user and a data interface.

2. The method according to claim 1, wherein the digital twin of the chromatograph is being run with a selectable concentration of the virtual representation of least one substance of the selected multiplicity of substances.

3. The method according to claim 1, wherein the multiplicity of substances is selected through at least one of a statistical algorithm, a process model and a knowledge database.2024007554. The method according to claim 1, wherein the degrees of membership between the chromatogram with the peak at the unspecified position and the virtual chromatograms are determined based on at least one of a comparison of the position of the peak caused by the unspecified substance in the chromatogram and a position of a virtual peak in the corresponding virtual chromatogram that is caused by the virtual representation of the substance from the selected multiplicity of substances, and at least one geometric parameter that defines the shape of the peak caused by the unspecified substance in the chromatogram and the virtual peak caused by the virtual representation of the substance from the selected multiplicity of substances in virtual chromatogram.

5. The method according to claim 1, wherein the digital twin is configured to mirror the retention effect of a separating means of the chromatograph.

6. The method according to claim 1, the method further comprising the steps:Running the digital twin to mirror the operation of the chromatograph and comparing the at least one chromatogram to a corresponding virtual chromatogram, the virtual chromatogram being generated by the digital twin;Determining a deviation between at least one peak in the chromatogram and a corresponding peak in the virtual chromatogram;Varying at least one of an ambient parameter and an operating parameter of the digital twin to match a virtual chromatogram to the corresponding chromatogram and determining at least one varied ambient parameter or varied operating parameter of the digital twin;Outputting a type of at least one of the varied ambient parameter and the varied operating parameter to at least one of the user and the data interface.2024007557. The method according to claim 6, the method further comprising:Outputting a value of at least one of the varied ambient parameter and the varied operating parameter to at least one of the user and the data interface.

8. The method according to claim 6, the method further comprising:Determining if at least one of the varied ambient parameter and the varied operating parameter exceed a predefined threshold;Outputting a warning to at least one of the user and the data interface indicating a defective state of the chromatograph if at least one of the varied ambient parameter and the varied operating parameter exceeds the predefined threshold.

9. The method according to claim 6, wherein a deteriorated component of the chromatograph is determined based on the type of at least one of the varied ambient parameter and the varied operating parameter.

10. A twinned physical -digital system, comprising a chromatograph and a digital twin of the chromatograph, the twinned physical-digital system being configured to perform the method according to claim 1.

11. A method for diagnosing a chromatograph of a twinned physical-digital system, the twinned physical-digital system comprising a digital twin of the chromatograph, the method comprising:Operating the chromatograph and determining at least one chromatogram for a composition of a sample that is fed into the chromatograph;Running the digital twin to mirror the operation of the chromatograph and comparing the at least one chromatogram to a corresponding virtual chromatogram, the virtual chromatogram being generated by the digital twin;Determining a deviation between at least one peak in the chromatogram and a corresponding peak in the virtual chromatogram;Varying at least one of an ambient parameter and an operating parameter of the digital twin to match the virtual chromatogram to the corresponding chromatogram and202400755 determining at least one varied ambient parameter or varied operating parameter of the digital twin;Outputting a type of at least one of the varied ambient parameter and the varied operating parameter to at least one of the user and the data interface.

12. The method according to claim 11, the method further comprising:Outputting a value of at least one of the varied ambient parameter and the varied operating parameter to at least one of the user and the data interface.

13. The method according to claim 11, the method further comprising:Determining if at least one of the varied ambient parameter and the varied operating parameter exceed a predefined threshold;Outputting a warning to at least one of the user and the data interface indicating a defective state of the chromatograph if at least one of the varied ambient parameter and the varied operating parameter exceeds the predefined threshold.

14. The method according to claim 11, wherein a deteriorated component of the chromatograph is determined based on the type of at least one of the varied ambient parameter and the varied operating parameter.

15. A twinned physical -digital system, comprising a chromatograph and a digital twin of the chromatograph, the twinned physical-digital system being configured to perform the method according to claim 11.

16. A computer program product that is stored on a non-transitory storage medium, the computer program product comprising program code that is configured to perform the following steps when loaded into a memory of a computer:Receiving signals from a chromatograph, generating chromatograms based on the received signals and detecting a number of peaks in at least one of the chromatograms, the number of peaks reflecting the number of substances in a sample analyzed in the chromatograph when the202400755 sample only comprises specified substances according to a preset specification, each of the peaks being substantially at a specified position in the chromatograms;Detecting a presence of at least one unspecified substance in the sample when a peak is detected at an unspecified position and isolating peak at the unspecified position;Selecting a multiplicity of substances from a database as potential unspecified substances and feeding virtual representations of substances from the selected multiplicity of substances into a digital twin of the chromatograph;Running a digital twin of the chromatograph with the virtual representations and generating virtual chromatograms;Determining degrees of membership between the virtual chromatograms and a chromatogram that comprises the peak at the unspecified position, determining at least one virtual chromatogram that shows at least a selectable minimum degree of membership and determining the substance that corresponds to the at least one determined virtual chromatogram as the unspecified substance;Outputting the determined substance to at least one of a user and a data interface.

17. The computer program product according to claim 16, the computer program product comprising at least one of the digital twin, the database and a data interface that is configured to connect the computer program product to the chromatograph.

18. A control unit configured for controlling an operation of a chromatograph, the control unit comprising a memory and a processor for running computer program product, the control unit comprising a computer program product that is embodied according to claim 17.

19. A method for operating a chemical production system that is configured to perform a chemical production process, the chemical production system comprising a first stage at which an intermediary product is produced, a second stage at which the intermediary product is processed and a measurement stage between the first and second stage of the chemical production system, at which a composition of a sample of the intermediary product is determined through a chromatograph, the method comprising:202400755Measuring a composition of the sample and generating chromatograms which reflect the measured composition, the chromatograms comprising a number of peaks which corresponds to the number of substances in the sample when the sample only comprises specified substances according to a preset specification, each of the peaks being substantially at a specified position in the chromatograms;Detecting a presence of at least one unspecified substance in the sample when a peak is detected at an unspecified position in at least one chromatogram;Selecting a multiplicity of substances from a database as potential contaminants and feeding the selected multiplicity of substances into a digital twin of the chromatograph;Running the digital twin of the chromatograph with virtual representations of substances from the selected multiplicity of substances and generating virtual chromatograms;Determining degrees of membership between the virtual chromatograms and a chromatogram that comprises the peak at the unspecified position, determining at least one virtual chromatogram that shows at least a selectable minimum degree of membership and determining the substance that corresponds to the at least one determined virtual chromatogram as the unspecified substance;Outputting the determined substance to at least one of a knowledge database and an artificial intelligence algorithm and determining at least one of a root cause for the presence of the unspecified substance in the sample and a countermeasure to remove the unspecified substance from the chemical production process.

20. A chemical production system, comprising a first stage at which an intermediary product is produced, a second stage at which the intermediary product is processed and a measurement stage between the first and second stage of the chemical production system, the measurement stage comprising a chromatograph, the chromatograph being configured to measure a composition of a sample of the intermediary product, the chemical production system being configured to perform a method according to claim 19.

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