Computer-implemented method for outputting the coking of a steam cracker

Abstract

NOT VISIBLE DUE TO STATUS OF PATENT

Description

[0001] "Computer-implemented method for the dispensing of coking of a steam

[0002] Crackers"

[0003] FIELD OF THE INVENTION

[0004] The invention relates to a method for determining the coking of a reactor tube of a steam cracker and a method for determining the aging of a reactor tube of a steam cracker.

[0005] STATE OF THE ART

[0006] In steam crackers, hydrocarbons, such as those from petroleum fractions, are mixed with steam and passed through tubes arranged in a heated furnace. The hydrocarbons are thermally cracked in the reactor tubes, producing a wide range of hydrocarbon compounds.

[0007] During steam cracking, coke is produced during the splitting of hydrocarbons. This coke is deposited on the reactor tube walls during the process. This deposit is referred to as coking. This leads, on the one hand, to an increased pressure drop across the reactor tubes. Steam cracking must be stopped when a critical pressure drop occurs. On the other hand, more energy must be used to heat the reactor tubes due to coking. The amount of energy that can be supplied to heat the reactor tubes is limited by the temperature resistance of the reactor tubes. Therefore, the energy supply cannot be increased indefinitely. Therefore, in the event of a critical pressure drop or a limited energy supply, the steam cracking process must be stopped in order to free the reactor tubes of coke by burning them off.

[0008] Coking in the steam cracker is therefore an important and limiting factor for steam cracker control. However, there are no known ways to determine coking in the steam cracker to optimize steam cracker control. Further complicating the situation is the transient nature of the steam cracking process, as coking occurs during the cracking of hydrocarbons due to both pyrolytic coking and catalytic coking. In particular, there is no known method that can detect catalytic coking separately from pyrolytic coking in situ.

[0009] While pyrolytic coking is primarily determined by the mixture of petroleum fractions and steam, catalytic coking is significantly influenced by the corrosion progression of the reactor tubes. Tubes with advanced corrosion exhibit higher levels of catalytic coking. Therefore, determining catalytic coking is of particular interest in determining the corrosion progression. The corrosion progression correlates directly with the aging of the reactor tubes.

[0010] The object of the present invention is therefore to propose an efficient and easily implemented method for outputting the coking of a steam cracker, wherein the coking is precisely determined and the control of the steam cracker is facilitated. Furthermore, the object of the invention is to propose a computer-implemented method for determining the aging of a steam cracker.

[0011] SUMMARY OF THE INVENTION

[0012] According to a first aspect of the invention, the object is achieved by a computer-implemented method for outputting the coking of a steam cracker, characterized by the following steps: a. recording a pressure loss of the steam cracker and / or a temperature profile of the steam cracker, b. defining a coking of the steam cracker, c. simulating a pressure loss of the steam cracker and / or simulating a temperature profile of the steam cracker based on the coking defined in step b., d. correcting the coking defined in step b. to adjust the pressure loss simulated in step c. to the pressure loss recorded in step a. and / or correcting the coking defined in step b. to adjust the temperature profile simulated in step c. to the temperature profile recorded in step a., e. outputting the coking of the steam cracker corrected in step d.

[0013] The method according to the invention allows the coking of the steam cracker to be precisely determined. This simplifies and improves steam cracker control. In particular, the method according to the invention is particularly efficient and easy to implement.

[0014] Coking of a steam cracker can be the deposition of coke on the inner surface of the steam cracker. Coking can have a limiting and important influence on the control of the steam cracker. Coking can be described, in particular, as a function of the path of the steam cracker. Thus, coking can be described variably along the steam cracker. Coking can be the thickness of coke per unit area on the inner surface of the steam cracker. Coking can also be expressed as a coking rate. This can apply, in particular, to all disclosed coking processes.

[0015] The pressure loss of the steam cracker can be measured in step a. by using a pressure sensor. The pressure loss measured in step a. can be the difference between the inlet pressure and the outlet pressure of the steam cracker. Measuring the pressure loss includes every possible way of determining the pressure loss. In particular, the pressure loss measured in step a. can be the actual pressure loss of the steam cracker.

[0016] The temperature profile of the steam cracker can be recorded in step a. by measuring it with a temperature sensor, such as a thermostat, a thermocouple, a thermal camera, and / or an infrared camera. The temperature profile recorded in step a. can be recorded, in particular, for the entire steam cracker using at least one temperature sensor. The temperature profile of the stream cracker can be determined from at least one local temperature measurement and the interpolation of the temperature profile based on the at least one local temperature measurement.

[0017] The temperature profile of the steam cracker can be the temperature profile of the steam cracker's reactor tubes, in particular the outer surface of the steam cracker's reactor tubes. Defining coking of the steam cracker in step b. can be the specification of a coking value. The coking can be freely defined. For this purpose, the coking can be defined by estimation, from empirical values, and / or based on simulations. In particular, the coking defined in step b. cannot be based on measured values.

[0018] Simulating a pressure loss in step c. based on the coking defined in step b. can be the simulation of the pressure loss of the steam cracker, whereby the coking defined in step b. can be used as the assumption for the simulation. The simulation can be performed on a computer, a server, or a similar device. In particular, the pressure loss simulated in step c. cannot have been measured at the steam cracker. In particular, the pressure loss simulated in step c. can only be calculated.

[0019] Simulating a temperature profile of the steam cracker in step c. based on the coking defined in step b. can be the simulation of the temperature profile of the steam cracker, whereby the coking defined in step b. can be used as the assumption for the simulation. The simulation can be carried out on a computer, a server, or a similar device. In particular, the temperature profile simulated in step c. cannot have been measured on the steam cracker. In particular, the temperature profile simulated in step c. can only be calculated.

[0020] The correction of the coking defined in step b. to adjust the pressure loss simulated in step c. to the pressure loss recorded in step a. and / or the correction of the coking defined in step b. to adjust the temperature profile simulated in step c. to the temperature profile recorded in step a. can be an increase or reduction in coking. In other words, the thickness of the coke per unit area on the inner surface of the steam cracker can be corrected. In this way, the corrected coking can be determined from the coking defined in step b. The corrected coking can correspond to the actual coking of the steam cracker. The coking correction in step d. can only be calculated here. The correction in step d. can be carried out independently of the steam cracker.

[0021] The output of the steam cracker coking corrected in step d. can be a reproduction of the coking corrected in step d. The output can be presented in a manner understandable to an operator. The output can be presented, for example, as a number, function, or graphic. The output can be presented visually and / or acoustically. The output can be the transmission of information about the steam cracker coking corrected in step d. The transmission can be used for further use in another process or for further determinations, for example, the determination of catalytic coking.

[0022] The method is a computer-implemented method and can therefore be carried out on a computer such as a server, a laptop, a personal computer, or the like. A computer-implemented method can be understood, for example, to mean that the computer performs some or all steps of the method. The computer can be understood as a physical device with hardware components.

[0023] Furthermore, a device configured to carry out the method for outputting the coking of a steam cracker and / or for carrying out the method for determining the aging of a steam cracker is disclosed, wherein the device comprises means configured to carry out the disclosed methods. The device is, for example, a device for carrying out the method for outputting the coking of a steam cracker and / or for carrying out the method for determining the aging of a steam cracker.

[0024] The means may comprise hardware components and / or software components. The means may, for example, comprise at least one memory with program instructions of a computer program (e.g., the computer program disclosed below) and at least one processor configured to execute program instructions from the at least one memory. Accordingly, a device is also to be understood as being disclosed that comprises at least one processor and at least one memory with program instructions, wherein the at least one memory and the program instructions are configured, together with the at least one processor, to cause the device to execute the disclosed method.

[0025] Alternatively or additionally, the means may further comprise one or more communication interfaces (e.g., one or more wired and / or wireless communication interfaces, e.g., a wireless communication interface in the form of a radio interface) and / or one or more user interfaces (e.g., a keyboard, a mouse, a screen, a touchscreen, a loudspeaker, a microphone, etc.). It is understood that the disclosed device may also comprise other means not listed. Furthermore, a computer program is disclosed, the computer program comprising program instructions configured to cause a computer, when executed by at least one processor, to execute the disclosed methods.

[0026] The disclosed computer program is, for example, contained and / or stored on a computer-readable storage medium. A computer-readable storage medium is understood to mean, for example, a physical and / or tangible storage medium.

[0027] In one embodiment, the correction according to step d. of the coking defined in step b. can be carried out iteratively, wherein the correction of the coking defined in step b. for adjusting the simulated pressure loss to the detected pressure loss according to step d. and / or the correction of the coking defined in step b. for adjusting the simulated temperature profile to the detected temperature profile according to step d. can comprise the following steps: d.1. Comparing the simulated pressure loss with the detected pressure loss and / or comparing the simulated temperature profile with the detected temperature profile, d.2. Correcting the coking defined in step b., d.3. Simulating the pressure loss of the steam cracker based on the coking corrected in step d.2 and / or simulating the temperature profile of the steam cracker based on the coking corrected in step d.2.

[0028] Through iterative correction, the correction and thus the process can determine the coking of the steam cracker with particular precision. This can facilitate steam cracker control. The process can also be particularly efficient and easy to implement. If the process can encompass steps d1 to d3, the process can be particularly stable and thus particularly efficient.

[0029] Iterative may mean that the correction can be repeated, for example until the simulated pressure loss can match the measured pressure loss.

[0030] In one embodiment, the coking defined in step b. can be defined by pyrolytic coking in the steam cracker.

[0031] In this way, the coking defined in step b. can be determined particularly accurately, as the coking defined in step b. can be very close to the actual coking of the steam cracker. This allows the simulation in step c. to be particularly accurate. This allows the method to determine the coking of the steam cracker particularly precisely and efficiently. This can facilitate and improve steam cracker control.

[0032] Pyrolytic coking can be the coking of the steam cracker by the mixture of petroleum fractions and steam.

[0033] In one embodiment, the computer-implemented method may comprise the method step: f. determining catalytic coking by subtracting the pyrolytic coking from the coking corrected in step d. and outputting the catalytic coking.

[0034] In this way, coking in the steam cracker can be precisely determined, as the individual components of coking, particularly pyrolytic coking and catalytic coking, can be precisely determined. This allows both the proportion of pyrolytic coking and the proportion of catalytic coking to be determined in relation to the total coking. This allows for a better assessment of the cause of coking, thus facilitating and improving steam cracker control. In particular, this method allows for the determination of coking, and especially pyrolytic coking and catalytic coking, to be carried out particularly efficiently and easily.

[0035] Catalytic coking can be the formation of coke due to the catalytic reaction of the gas on the inner surface of the tubes. For example, catalytic coking can depend on the chemical composition of the inner surface of the tubes. A catalytically inactive material, such as chromium oxide, silicon oxide, and / or aluminum oxide, can reduce catalytic coking. The catalytically inactive material can, in particular, form a layer on the inner surface. Catalytically active materials, such as nickel and / or iron, can support catalytic coking.

[0036] In particular, when performing step f., the output of the steam cracker coking corrected in step d. according to step e. can be replaced by the output of the catalytic coking according to step f. Alternatively or additionally, the pyrolytic coking and / or the coking corrected in step b. can be output.

[0037] In one embodiment, at least one process parameter of the steam cracker can be recorded in step a., and wherein in step b. the simulated pressure loss and / or in step b. the simulated temperature profile can be additionally simulated based on the at least one process parameter of the steam cracker. In this way, the method can be more precise. Furthermore, with the at least one process parameter, the method can be more efficient and easier to carry out, since the simulation of the pressure loss in step c. can be improved. This can also facilitate the control of the steam cracker.

[0038] The at least one process parameter can be a value or a property of the steam cracker or the steam cracking process. The at least one parameter can influence coking and / or pressure drop in the steam cracker. The at least one parameter can be incorporated into the simulation in step c.

[0039] In one embodiment, the at least one process parameter can represent one of the following variables and / or properties: a geometry of the steam cracker, an inlet pressure, wherein in particular the inlet pressure can be determined by means of a pressure sensor, an outlet pressure, wherein in particular the outlet pressure can be determined by means of a pressure sensor, a mass flow, wherein in particular the mass flow can be detected by means of a mass flow sensor, at least one input product, wherein in particular the at least one input product can be determined by means of a PIONA analysis and / or gas chromatography, in particular multidimensional gas chromatography, at least one output product, wherein in particular the at least one output product can be determined by means of residual gas analysis and / or gas chromatography, in particular multidimensional gas chromatography, a vapor ratio,an inlet temperature of the at least one input product, wherein in particular the inlet temperature can be determined by means of a temperature sensor, an outlet temperature of the at least one output product, wherein in particular the outlet temperature can be determined by means of a temperature sensor, a heat flow profile, a time, wherein in particular the time can be measured by means of a time measuring device.

[0040] This allows the process to become more precise, as the at least one process parameter can significantly influence the coking of the steam cracker. Furthermore, the at least one process parameter can make the process more efficient and easier to implement, as the pressure drop in step c can be simulated more quickly and accurately based on the at least one process parameter. This can also facilitate the control of the steam cracker.

[0041] The geometry of the steam cracker can be the layout of the steam cracker's reactor tubes. The geometry can be determined from technical drawings or a design file, such as a CAD file. Alternatively, or additionally, the geometry of the steam cracker can be measured.

[0042] The geometry of the steam cracker allows the temperature profile and coking profile to be determined with pinpoint accuracy. This allows the thermal load and aging of the individual steam cracker tubes to be determined. This method can be used to make the steam cracker more efficient, for example, by adjusting the material selection or by replacing only defective reactor tubes.

[0043] The inlet pressure can be the pressure of the at least one input product at the inlet of the steam cracker. The inlet pressure can be the pressure at which the at least one input product can be fed to the steam cracker. The inlet pressure can be determined particularly easily using a pressure sensor.

[0044] In this way, the pressure loss across the steam cracker can be calculated, making the process more precise and efficient.

[0045] The outlet pressure can be the pressure of the at least one output product at the outlet of the steam cracker. The outlet pressure can be the pressure at which the at least one output product can escape from the steam cracker. The outlet pressure can be determined particularly easily using a pressure sensor.

[0046] In this way, the pressure loss across the steam cracker can be calculated, making the process more precise and efficient.

[0047] The mass flow can be the volume flow through the steam cracker. The mass flow can be measured using a mass flow sensor. The mass flow can be determined, for example, via the pressure drop at the orifice plates and / or by measuring the Coriolis forces. From this, the mass flow can be calculated. Alternatively or additionally, the mass flow can be determined from the density as a function of temperature and composition.

[0048] The required energy and flow velocity can be determined from the mass flow. These can influence the pressure drop, making the process more accurate.

[0049] The at least one input product can be the product introduced into the steam cracker. In particular, there can also be multiple input products. The at least one input product can comprise, for example, ethane, butane, other longer-chain paraffins, cycloalkanes, or a mixture thereof.

[0050] The at least one input product can be determined using a PIONA analysis and / or gas chromatography, in particular multidimensional gas chromatography. The at least one input product can be determined according to DIN EN ISO 22854, ASTM D5134-21, or ASTM D86-23.

[0051] The at least one starting product can be the product discharged from the steam cracker. In particular, multiple starting products can also be present. The at least one starting product can comprise, for example, an olefin, ethylene, propylene, uncracked ethane, or a mixture thereof.

[0052] The at least one starting product can be determined using residual gas analysis and / or gas chromatography, in particular multidimensional gas chromatography. The at least one starting product can be determined according to DIN EN ISO 22854, ASTM D5134-21, or ASTM D86-23.

[0053] The steam ratio can be the ratio of steam to hydrocarbons. The steam ratio can be the quotient of the mass flow of steam and the mass flow of at least one input product. The steam ratio can be set by the steam cracker operator. The steam ratio can also be the steam-oil ratio of the steam cracker.

[0054] The inlet temperature of the at least one input product can be the temperature of the at least one input product upon introduction into the steam cracker. The inlet temperature can be determined using a temperature sensor. The temperature sensor can be a thermocouple, a pyrometer, an optoelectronic sensor, and / or a thermal imaging camera. The outlet temperature of the at least one output product can be the temperature of the at least one output product upon discharge from the steam cracker. The outlet temperature can be determined using a temperature sensor. The temperature sensor can be a thermocouple, a pyrometer, an optoelectronic sensor, and / or a thermal imaging camera.

[0055] The heat flow profile can be the heat energy that is transported from a high-temperature location to a low-temperature location over a period of time. In a steam cracker, the heat flow profile can be the transport of heat from the heated outside of the reactor tubes to the inside of the reactor tubes. The heat flow profile can be determined based on surface temperature measurements. Alternatively or additionally, the heat flow profile can be determined based on the outlet temperature and the at least one starting product. Alternatively or additionally, a profile can be estimated via the burner arrangement. Alternatively or additionally, the heat flow profile can be determined based on CFD simulations of the burners in the steam cracker.

[0056] The time can be the operating time of the steam cracker. The time can be measured using a timing device. A timing device can be a stopwatch, for example. The time allows the amount of coking to be estimated particularly accurately, since the amount of at least one input product and at least one output product can be determined.

[0057] In one embodiment, the method may be performed periodically.

[0058] In this way, the process allows for continuous monitoring of the steam cracker's coking. This allows for particularly precise determination of coking. Furthermore, the efficiency of the process can be improved. Furthermore, the process is easy to implement, as the steam cracker's coking can be continuously monitored. All of this can, in turn, facilitate steam cracker control.

[0059] Periodically can mean that the process is carried out at regular intervals. The intervals can be chosen such that a measurable change in the pressure loss recorded in step a. due to coking can be detected.

[0060] In one embodiment, the process can be carried out daily, preferably hourly. This allows the coking of the steam cracker to be continuously and closely monitored. This allows the coking to be determined particularly precisely. Furthermore, the efficiency of the process can be improved. Furthermore, the process can be easily implemented because the coking of the steam cracker can be monitored daily. All of this can, in turn, facilitate the control of the steam cracker. If the process is carried out hourly, the aforementioned advantages are further enhanced.

[0061] In one embodiment, the method can be applied for an entire run of the steam cracker.

[0062] In this way, the method can simulate the coking of the steam cracker throughout its entire run. This allows for particularly precise determination of coking, especially since initial coking can be easily determined, as no coking may be present at the beginning of a run. This makes the method particularly efficient and easy to implement. This then facilitates steam cracker control.

[0063] The entire run of a steam cracker can be the operation of the steam cracker between two decokings. The run can be from the beginning of the steam cracker's use after a decoking to the end of the steam cracker's use for another decoking. Decoking can be the burning of coke from the steam cracker. At the beginning of the run, there may be no coking in the steam cracker. At the end of the run, the steam cracker may be at its maximum coking level.

[0064] According to one embodiment, a method for simulating the steam cracking of hydrocarbons in steam crackers can be used for the method, in particular steps b. and c.

[0065] One method for simulating steam cracking of hydrocarbons in steam crackers can be the program COILSIM1 D.

[0066] The program COILSIM1D was developed to simulate the steam cracking of hydrocarbons in reactor tubes. To model the reactions that can occur during the process, a reaction network can be used. The reaction network can consist of two schemes: a monomolecular p-network and a ß-network. This can be based in particular on chapters 2.1-2.3 of the doctoral thesis "Single Event Micro kinetic Model for Steam Cracking of Hydrocarbons" by Kevin van Geern (ISBN 90-8578-077-2). To model the reactors for steam cracking, a steam cracker model may also be required. The model equations can be based on a one-dimensional model in which it can be assumed that no gradients of the variables to be calculated can exist in the radial direction. The exception can be the temperature profile in the region of the very thin film near the wall.This gradient cannot be neglected, as it can be crucial for heat transfer. The flow can be assumed to be plug flow. The model equations can include the transport equations for mass, momentum, and energy, also known as the Navier-Stokes equation. These equations can be integrated along the steam cracker coil and can ultimately yield the product yields as well as the pressure and temperature profiles across the reactor tubes. This can be based in particular on Chapter 4 of Kevin van Geern's doctoral thesis "Single Event Microkinetic Model for Steam Cracking of Hydrocarbons" (ISBN 90-8578-077-2).

[0067] To simulate the run length of industrial steam cracking, the following two coking models can be integrated into the basic simulation model. The coking model by Plehiers et al. (Plehiers PM Rigoureuze Modellen voor de Simulatie van Fornuizen voor de Thermische Kraking van Lichte Koolwaterstoffen, PhD dissertation, UGent, 1989) was developed to predict coking rates in the steam cracking of light hydrocarbon feedstocks. The model by Reyniers et al. (Reyniers GC, Froment GF, Kopinke FD, Zimmerman G. Coke Formation in the Thermal Cracking of Hydrocarbons. 4. Modeling of Coke Formation in Naphtha Cracking, Ind. Eng. Chem. Res., 33, 2584, 1994.) enables the simulation of the coking rate of heavier feedstocks ranging from light naphtha fractions to condensates.

[0068] However, both coking models can only account for heterogeneous non-catalytic or so-called pyrolytic coking. The coking kinetics can be coupled with the one-dimensional reactor model equations, which can be solved in the program. This can be based in particular on Chapter 5, especially Chapter 5.2.4, of Kevin van Geern's doctoral thesis "Single Event Microkinetic Model for Steam Cracking of Hydrocarbons" (ISBN 90-8578-077-2).

[0069] According to a second aspect of the invention, the object is achieved by a computer-implemented method for determining the aging of a steam cracker, characterized by the following steps: a. Determining the catalytic coking using the method according to the invention for outputting the coking of a steam cracker, b. Comparing the catalytic coking with a catalytic reference coking, c. Outputting the result of the comparison in step b. as the aging of the steam cracker.

[0070] In this way, the aging and thus the condition of the steam cracker can be determined with particular precision, facilitating steam cracker control. This allows not only the aging and condition of the steam cracker to be determined, but also the risk of a reactor tube rupture, thus increasing the safety of the steam cracker. Furthermore, the process is particularly efficient and easy to implement.

[0071] The aging of a steam cracker can be the condition of the steam cracker's reactor tubes. In particular, the aging can correspond to the wear and tear of the steam cracker's reactor tubes. The wear and tear of the reactor tubes can be the initial wall thickness up to a critical wall thickness. The critical wall thickness can be the wall thickness at which failure of the steam cracker's reactor tubes, such as breaking, bursting, and / or rupturing of the steam cracker's reactor tubes, can still be prevented. The remaining wall thickness can be determined based on carburization and / or nitriding. In particular, the aging can be output for the individual reactor tubes of the steam cracker.

[0072] Aging can be the progression of corrosion. For example, the progression of corrosion can be a change in the inner surface of the tubes, in particular a change in the chemical composition of the inner surface of the tubes. For example, the progression of corrosion can be an increase in a catalytically active material, such as nickel and / or iron, on the inner surface of the tubes. Alternatively or additionally, the progression of corrosion can be a change in the chemical composition of the material from the inner surface to the outer surface of the tubes. For example, the change in the chemical composition of the material from the inner surface to the outer surface of the tubes can be carburization and / or nitriding.

[0073] For example, at the beginning of the service life, a certain amount of catalytically inactive material may be present on the inner surface. The catalytically inactive material may be an oxide layer, such as chromium oxide, silicon oxide, and / or aluminum oxide, on the inner surface. The catalytically inactive material may, in particular, form a layer on the inner surface. In addition, the catalytically inactive material can prevent carburization and / or nitriding of the tube. With increasing aging, the amount of catalytically inactive material on the inner surface may decrease. With increasing aging, an increasing amount of catalytically active material, such as nickel and / or iron, may be present on the inner surface of the tubes. In this way, catalytic coking and / or carburization and / or nitriding may increase. The catalytically inactive material can reduce catalytic coking.The catalytically active material can support catalytic coking.

[0074] The catalytic reference coking can be a value for the coking at the end of the steam cracker's lifetime. As the steam cracker ages, the alloying elements in the reactor tubes, which can form a protective oxide layer, can decrease. Therefore, with increasing age, catalytic coking can increase, so that the maximum catalytic coking at the end of the steam cracker's lifetime can be the catalytic reference coking. The catalytic reference coking can be determined empirically or from experience.

[0075] The comparison in step b. of the catalytic coking with the catalytic reference coking can be a comparison of the absolute values ​​and / or a ratio of the catalytic coking and the catalytic reference coking. The comparison can be output, in particular, as a proportion of the catalytic coking determined in step a. compared to the catalytic reference coking, in particular as a percentage.

[0076] The result of the comparison in step b. as the aging of the steam cracker can be output visually and / or acoustically.

[0077] According to one embodiment, the catalytic reference coking can be determined at the end of the lifetime of a steam cracker.

[0078] In this way, the aging and thus the condition of the steam cracker can be determined particularly precisely, since the catalytic reference coking rate can be derived from empirical data. This can facilitate steam cracker control. Thus, in addition to the aging and condition of the steam cracker, the risk of a reactor tube rupture in the steam cracker can also be determined particularly accurately, so that the safety of the steam cracker can be increased with the method. Furthermore, the method can be particularly efficient and easy to implement. The steam cracker for determining the catalytic reference coking rate at the end of its service life can be any steam cracker.

[0079] The catalytic reference coking at the end of the lifetime of a steam cracker may be the maximum catalytic coking at the end of the lifetime of the steam cracker. According to one embodiment, the catalytic reference coking may be determined from historical data of the same steam cracker.

[0080] In this way, the aging and thus the condition of the steam cracker can be determined with particular precision, since the catalytic reference coking can be derived from empirical data from the same steam cracker. This can facilitate steam cracker control. Thus, in addition to the aging and condition of the steam cracker, the risk of a reactor tube rupture in the steam cracker can also be determined with particular accuracy, thus increasing the safety of the steam cracker. Furthermore, the process can be particularly efficient and easy to implement.

[0081] The steam cracker whose aging is to be determined may be the same steam cracker on which the catalytic reference coking was determined. Thus, it may be the same steam cracker, although individual reactor tubes may have been replaced.

[0082] According to a third aspect of the invention, the object is achieved by a device configured to carry out the method according to the invention for outputting the coking of a steam cracker and / or to carry out the method according to the invention for determining the aging of a steam cracker, or comprising respective means for carrying out the steps of the method according to the invention for outputting the coking of a steam cracker and / or comprising respective means for carrying out the steps of the method according to the invention for determining the aging of a steam cracker.

[0083] According to a fourth aspect of the invention, the object is achieved by a computer program comprising program instructions which, when executed by at least one processor, are designed to cause a device to carry out the method according to the invention for outputting the coking of a steam cracker and / or the method according to the invention for determining the aging of a steam cracker.

[0084] Further objects, features, advantages, and aspects of the present invention will become apparent to those skilled in the art from the following description and the appended claims. However, it should be understood that the following description, the appended claims, and the specific examples showing preferred embodiments of the invention are given for illustrative purposes only. Various changes and modifications within the spirit and scope of the disclosed invention will be readily apparent to those skilled in the art upon reading the following.

[0085] DEFINITIONS

[0086] The following expressions generally have the meanings set out below, unless the context in which they are used indicates otherwise.

[0087] As used herein, the term "comprise," in addition to its literal meaning, includes and specifically refers to the terms "consist essentially of" and "consist of." Thus, the term "comprise" refers both to embodiments in which the subject matter "comprises" specifically listed elements and does not include any other elements, as well as to embodiments in which the subject matter "comprises" specifically listed elements and / or may include other elements. Likewise, the term "have" is to be understood as the term "comprise," which also includes and refers to the terms "consist essentially of" and "consist of."The expression "consist essentially of" refers, where possible, in particular to embodiments in which the article comprises, in addition to the specifically listed elements of which the article essentially consists, 20% or less, in particular 15% or less, 10% or less, or in particular 5% or less, of further elements.

[0088] FIGURES a flowchart of an embodiment of a computer-implemented

[0089] Method for discharging the coking of a steam cracker according to the

[0090] Invention; Fig. 2 is a flowchart of an embodiment of step d. of the computer-implemented method according to the invention; Fig. 3 is a schematic view of a steam cracker; Fig. 4 is a flowchart of an embodiment of a computer-implemented

[0091] Method for determining the ageing of a steam cracker according to

[0092] Invention;

[0093] Fig. 5 shows a cross section through an aged reactor tube, Fig. 7 shows a schematic representation of an embodiment of a device according to the invention.

[0094] SPECIAL DESCRIPTION

[0095] Fig. 1 shows a flowchart of an embodiment of a computer-implemented method according to the invention.

[0096] The computer-implemented method comprises the following steps: a. detecting a pressure drop of the steam cracker, b. defining a coking of the steam cracker, c. simulating a pressure drop of the steam cracker based on the coking defined in step b., d. correcting the coking defined in step b. to adjust the pressure drop simulated in step c. to the pressure loss detected in step a., e. outputting the coking corrected in step d., f. determining catalytic coking by subtracting the pyrolytic coking from the coking corrected in step d. and outputting the catalytic coking.

[0097] In the method, a pressure loss of the steam cracker is first recorded in step 100. In step 101, coking of the steam cracker is defined. Subsequently, in step 103, a pressure loss of the steam cracker is simulated based on the coking defined in step 101. In step 104, the coking defined in step 101 is corrected to adjust the pressure loss simulated in step 102 to the pressure loss recorded in step 100. The coking corrected in step 103 is then output. Subsequently, catalytic coking is determined by subtracting the pyrolytic coking from the coking corrected in step 103, and the catalytic coking is output.

[0098] However, it is also possible to end the method with the output of the coking corrected in step 103 according to step 104. Furthermore, when performing step 105, the output of the steam cracker coking corrected in step 103 according to step 104 can be replaced by the output of the catalytic coking according to step 105. Alternatively or additionally, the pyrolytic coking and / or the coking corrected in step 101 can be output. The coking defined in step 101 is defined by the pyrolytic coking in the steam cracker.

[0099] Fig. 2 shows a flowchart of an embodiment of step 103 of the method according to the invention.

[0100] The correction according to step 103 of the coking defined in step 101 is performed iteratively. To this end, the correction of the coking defined in step 101 to adjust the simulated pressure loss to the recorded pressure loss according to step 103 includes the following steps:

[0101] In step 200, the simulated pressure loss is compared with the measured pressure loss. Subsequently, in step 201, the coking defined in step 101 is corrected. In the next step 202, the pressure loss of the steam cracker is simulated based on the coking corrected in step 201.

[0102] In the method shown in Fig. 1, at least one process parameter of the steam cracker can be recorded in step 100. In step 101, the simulated pressure loss is then additionally simulated based on the at least one process parameter of the steam cracker.

[0103] Fig. 3 shows a schematic view of a steam cracker 300. Using the steam cracker 300 as an example, it is explained how the various process parameters can be determined at the steam cracker 300. The process parameters can be, for example, the geometry of the steam cracker 300, the inlet pressure, the outlet pressure, the mass flow, at least one input product, at least one output product, the inlet temperature of the at least one input product, the outlet temperature of the at least one output product, the heat flow profile, and / or time.

[0104] The inlet pressure and the outlet pressure are each determined by a pressure sensor. The mass flow is measured by a mass flow sensor. The inlet temperature of the at least one input product and the outlet temperature of the at least one output product are determined by a temperature sensor.

[0105] Fig. 3 shows a schematic view of a steam cracker 300. The steam cracker 300 comprises a plurality of burners 301. The stream cracker 300 also comprises the first sensor 301 for determining a process parameter and the second sensor 302 for determining a process parameter. The first sensor 302 is arranged at the inlet of the steam cracker. The first sensor 302 can be designed to determine the inlet pressure, the mass flow, the inlet temperature, the steam ratio, or the at least one input product. Instead of a first sensor 302, a plurality of first sensors 302 can also be arranged at the inlet of the steam cracker 300 in order to determine two, three, four, five, or more process parameters. For example, with a plurality of first sensors 302, two, three, four, or five process parameters can also be determined from the process parameters inlet pressure, mass flow, inlet temperature, steam ratio, or the at least one input product.

[0106] The second sensor 303 is arranged at the outlet of the steam cracker. The second sensor 303 can be configured to determine the outlet pressure, the outlet temperature, or the at least one output product. Instead of a single second sensor 303, a plurality of second sensors 303 can also be arranged at the outlet of the steam cracker 300 to determine two, three, or more process parameters. For example, with a plurality of second sensors 303, two or three process parameters can also be determined from the process parameters outlet pressure, outlet temperature, or the at least one output product.

[0107] The process is carried out periodically. The process is carried out daily. Alternatively, the process can also be carried out hourly. In this case, the process is applied for the entire run of the steam cracker.

[0108] Fig. 4 shows a flowchart of an embodiment of a computer-implemented method for determining the aging of a steam cracker according to the invention;

[0109] The computer-implemented method for determining the aging of a steam cracker comprises the following steps: a. Determining the catalytic coking, b. Comparing the catalytic coking with a catalytic reference coking, c. Outputting the result of the comparison in step b. as the aging of the steam cracker.

[0110] As shown in the flowchart in Fig. 4, in step 400, the catalytic coking is first determined, as previously explained with reference to Fig. 1. Subsequently, in step 401, the catalytic coking is compared with the catalytic reference coking. Subsequently, in step 402, the result of the comparison in step 401 is output as the aging of the steam cracker. The catalytic reference coking is determined at the end of the service life of a steam cracker. Furthermore, the catalytic reference coking is determined from historical data of the same steam cracker.

[0111] Fig. 5 shows a cross-section through an aged reactor tube. The reactor tube exhibits carburization on the inside and nitriding on the outside. With increasing aging, both the carburization and nitriding increase. The area between the carburization and nitriding is the residual wall thickness.

[0112] Fig. 6 shows a cross-section through a reactor tube at the end of its service life. Compared to Fig. 5, it can be seen that carburization and nitriding have progressed further. The remaining wall thickness is so thin that the reactor tube should be replaced.

[0113] Fig. 7 shows a schematic representation of an embodiment of a device 7 according to the invention.

[0114] The device 7 comprises a processor 700 and, connected to the processor 700, a first memory as program memory 701, a second memory as main memory 702 and a network interface 703.

[0115] A processor 700 is understood to mean, for example, a microprocessor (central processing unit, CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a microcontroller, a field-programmable gate array (FPGA), or a graphics processor (GPU). It is understood that the device 7 can also comprise multiple processors 700.

[0116] The processor 700 executes program instructions stored in program memory 701 and stores, for example, intermediate results or the like in main memory 702. The use of an (additional) graphical processor may be advantageous, for example, for executing machine learning algorithms and / or artificial neural networks.

[0117] For example, program instructions are stored in program memory 701 which, when executing the program instructions, cause processor 700 to at least partially execute and / or control the method according to the first aspect of the invention. The method according to the first aspect of the invention is shown, for example, in Fig. 1. Alternatively or additionally, program instructions are stored in program memory 701 which, when executing the program instructions, cause processor 700 to at least partially execute and / or control the method according to the second aspect of the invention. The method according to the second aspect of the invention is shown, for example, in Fig. 3.

[0118] Program memory 701 further contains, for example, the operating system of the device 7, which is at least partially loaded into main memory 702 when the device 7 is started and executed by the processor 700.

[0119] An example of an operating system is a Windows UNIX, Linux, Android, Apple iOS, and / or MAC OS operating system. The operating system enables, in particular, the use of device 7 for data processing. For example, it manages resources such as a main memory and a program memory, provides basic functions to other computer programs through programming interfaces, among other things, and controls the execution of computer programs.

[0120] A program memory 701 is, for example, a non-volatile memory such as a flash memory, an EEPROM (electrically erasable programmable read-only memory), a magnetic memory, and / or an optical memory. A main memory 702 is, for example, a volatile or non-volatile memory, in particular a random access memory (RAM) such as a static random access memory (SRAM), a ferroelectric random access memory (FeRAM), a dynamic random access memory (DRAM), and / or a magnetic random access memory (MRAM).

[0121] Main memory 702 and program memory 701 can also be configured as one memory. Alternatively, main memory 702 and / or program memory

[0122] 701 can be formed by several memories. Furthermore, main memories

[0123] 702 and / or program memory 701 may also be part of the processor 700.

[0124] Processor 700 controls the network interface 703, which is configured, for example, to exchange information with a remote device via a connection in a communication network (e.g., to send and / or receive). In the following, it is assumed, by way of example, that the network interface 703 is a wired network interface. An example of a wired network interface is an Ethernet interface. For example, the device 7 can use the network interface 703 to output information such as the coking of the steam crackers or the aging of the steam cracker. For this purpose, the network interface 703 can be connected, for example, to a screen and / or a loudspeaker. The components 700 to 703 of the device 7 are connected, for example, via one or more bus systems (e.g.,One or more serial and / or parallel bus connections are communicatively and / or operatively connected to one another. It is understood that the device 7 may comprise further components (e.g., a user interface) in addition to the components 700 to 703. The device may be connected to an output device such as a screen and / or a loudspeaker.

Claims

PATENT CLAIMS:

1. Computer-implemented method for outputting the coking of a steam cracker, characterized by the following steps: a. recording a pressure loss of the steam cracker (100) and / or a temperature profile of the steam cracker, b. defining a coking of the steam cracker (101), c. simulating a pressure loss of the steam cracker and / or simulating a temperature profile of the steam cracker based on the coking (102) defined in step b., d. correcting the coking defined in step b. to adjust the pressure loss simulated in step c. to the pressure loss (103) recorded in step a. and / or correcting the coking defined in step b. to adjust the temperature profile simulated in step c. to the temperature profile recorded in step a., e. outputting the coking (104) corrected in step d.

2. Computer-implemented method according to claim 1, characterized in that the correction according to step d. of the coking defined in step b. is carried out iteratively, wherein the correction of the coking defined in step b. for adjusting the simulated pressure loss to the detected pressure loss according to step d. and / or the correction of the coking defined in step b. for adjusting the simulated temperature profile to the detected temperature profile according to step d. comprises the following steps: d.

1. Comparing the simulated pressure loss with the detected pressure loss (200) and / or comparing the simulated temperature profile with the detected temperature profile, d.

2. Correcting the coking defined in step b. (201), d.

3. Simulating the pressure loss of the steam cracker based on the coking corrected in step d.2 (202) and / or simulating the temperature profile of the steam cracker based on the coking corrected in step d.

2.

3. Computer-implemented method according to claim 1 or 2, characterized in that the coking defined in step b. is defined by pyrolytic coking in the steam cracker.

4. Computer-implemented method according to one of claims 1 to 3, comprising the additional method step: f. Determining a catalytic coking by subtracting the pyrolytic coking from the coking corrected in step d. and outputting the catalytic coking (105).

5. Computer-implemented method according to one of claims 1 to 4, characterized in that in step a. (100) at least one process parameter of the steam cracker is recorded, and wherein in step b. (101) the simulated pressure loss and / or in step b. the simulated temperature profile is additionally simulated based on the at least one process parameter of the steam cracker.

6. Computer-implemented method according to claim 5, characterized in that the at least one process parameter represents one of the following variables and / or properties: a geometry of the steam cracker, an inlet pressure, wherein in particular the inlet pressure is determined by means of a pressure sensor, an outlet pressure, wherein in particular the outlet pressure is determined by means of a pressure sensor, a mass flow, wherein in particular the mass flow is detected by means of a mass flow sensor, at least one input product, wherein in particular the at least one input product is determined by means of a PIONA analysis and / or gas chromatography, in particular multidimensional gas chromatography, at least one output product, wherein in particular the at least one output product is determined by means of residual gas analysis and / or gas chromatography, in particular multidimensional gas chromatography, a vapor ratio,an inlet temperature of the at least one input product, wherein in particular the inlet temperature is determined by means of a temperature sensor, an outlet temperature of the at least one output product, wherein in particular the outlet temperature is determined by means of a temperature sensor, a heat flow profile, a time, wherein in particular the time is measured by means of a time measuring device.

7. Computer-implemented method according to one of claims 1 to 6, characterized in that the method is carried out periodically.

8. A computer-implemented method according to claim 7; characterized in that the method is carried out daily, preferably hourly.

9. Computer-implemented method according to one of claims 1 to 8, characterized in that the method is applied for an entire run of the steam cracker.

10. A computer-implemented method according to any one of claims 1 to 9, characterized in that the method uses a method for simulating the steam cracking of hydrocarbons in steam crackers.

11. A computer-implemented method for determining the aging of a steam cracker, characterized by the following steps: a. Determining the catalytic coking according to claim 4 (400), b. Comparing the catalytic coking with a catalytic reference coking (401), c. Outputting the result of the comparison in step b. as the aging of the steam cracker (402).

12. Computer-implemented method according to claim 11, characterized in that the catalytic reference coking is determined at the end of the lifetime of a steam cracker.

13. Computer-implemented method according to claim 11 or 12, characterized in that the catalytic reference coking is determined from historical data of the same steam cracker.

14. Apparatus configured to carry out the method for outputting the coking of a steam cracker according to one of claims 1 to 10 and / or to carry out the method for determining the aging of a steam cracker according to one of claims 11 to 13, or comprising respective means for carrying out the steps of the method for outputting the coking of a steam cracker according to one of claims 1 to 10 and / or comprising respective means for carrying out the steps of the method for determining the aging of a steam cracker according to one of claims 11 to 13.

15. A computer program comprising program instructions which, when executed by at least one processor, are designed to cause a device to carry out the method for outputting the coking of a steam cracker according to one of claims 1 to 10 and / or the method for determining the aging of a steam cracker according to one of claims 11 to 13.