Modeling method and device for diesel aromatic hydrocarbon simulated moving bed adsorption separation device

Abstract

The invention discloses a modeling method and device for a diesel aromatic hydrocarbon simulated moving bed adsorption separation device, and the method comprises the steps: respectively constructing a bed mobile phase dynamic mechanism model and a bed stationary phase dynamic mechanism model of different components based on a material balance principle and a mass transfer mechanism; performing discretization processing based on a finite element method and an orthogonal configuration method to obtain a bed mobile phase dynamic mechanism discrete model and a bed stationary phase dynamic mechanism discrete model; respectively constructing node models of different components based on a material balance principle; and a bed layer dynamic mechanism discrete model of different components and an all-component bed layer dynamic mechanism discrete model are constructed, so that model parameters are optimized based on the all-component bed layer dynamic mechanism discrete model. The method can comprehensively, systematically and accurately reveal the quantitative relationship between numerous parameters of the diesel aromatic hydrocarbon simulated moving bed adsorption separation device and the performance indexes of the device, so that the optimization design and the optimization operation of the device are realized, and the method has important industrial application value.

Description

Technical Field

[0001] The present invention relates to the technical field of simulated moving bed adsorption separation, and particularly relates to a modeling method and device for a diesel aromatic simulated moving bed adsorption separation device. Background Art

[0002] Aromatics in industrial diesel raw materials are difficult to burn completely, which will cause environmental pollution. The diesel aromatic simulated moving bed adsorption separation device can separate the aromatics in industrial diesel raw materials and use them as high-value-added chemicals. At the same time, the remaining non-aromatics in industrial diesel raw materials become clean diesel. This device achieves the two major strategic goals of diesel cleaning and obtaining high-value-added chemical aromatics in a perfect way, and is an important milestone for the leapfrog development of the petrochemical industry.

[0003] Numerous bed layer parameters, operating parameters, kinetic parameters, adsorption isotherms, feed composition parameters, desorbent composition parameters, etc. of the diesel aromatic simulated moving bed adsorption separation device will affect the device performance indicators. By using modeling means to comprehensively, systematically and accurately reveal the quantitative relationship between these parameters and the device performance indicators, so as to realize the optimized design and optimized operation of the diesel aromatic simulated moving bed adsorption separation device, which has important industrial application value. Summary of the Invention

[0004] In order to realize the optimized design and optimized operation of the diesel aromatic simulated moving bed adsorption separation device, so as to enrich the process route and increase the selection space, the embodiments of the present invention provide a modeling method and device for a diesel aromatic simulated moving bed adsorption separation device.

[0005] In a first aspect, the embodiments of the present invention provide a modeling method for a diesel aromatic simulated moving bed adsorption separation device. The diesel aromatic simulated moving bed adsorption device may include: a plurality of bed layers, and adjacent bed layers are sequentially connected along the flow direction of the bed layer mobile phase. Sampling nodes, extract nodes, desorbent nodes and raffinate nodes are arranged between the bed layers, and the nodes move synchronously to the next bed layer along the flow direction of the bed layer mobile phase according to the step time, so as to realize the simulated moving operation of the diesel aromatic simulated moving bed adsorption separation device on the bed layers. The modeling method may include:

[0006] Based on the material balance principle and the mass transfer mechanism, respectively construct a dynamic mechanism model of the bed layer mobile phase and a dynamic mechanism model of the bed layer stationary phase for different components divided by the aromatic component, non-aromatic component and desorbent component in the diesel;

[0007] Based on the finite element method and the orthogonal collocation method, discretize the dynamic mechanism model of the bed layer mobile phase to obtain a discrete model of the dynamic mechanism of the bed layer mobile phase for different components;

[0008] The dynamic mechanism model of the bed stationary phase is discretized based on the orthogonal collocation method to obtain the dynamic mechanism discrete models of the bed stationary phase for different components;

[0009] Based on the material balance principle, node models for different components are constructed respectively; among them, the node models include: an injection node model, an extract node model, a desorbent node model, and a raffinate node model;

[0010] Based on the dynamic mechanism discrete model of the bed mobile phase, the dynamic mechanism discrete model of the bed stationary phase, and the node model, a dynamic mechanism discrete model of the bed for different components is constructed;

[0011] Based on the dynamic mechanism discrete models of the bed for different components, a dynamic mechanism discrete model of the entire component bed of the diesel aromatic simulated moving bed adsorption device is constructed to optimize the model parameters of the diesel aromatic simulated moving bed adsorption device based on the dynamic mechanism discrete model of the entire component bed.

[0012] Optionally, the discretization of the dynamic mechanism model of the bed mobile phase based on the finite element method and the orthogonal collocation method to obtain the dynamic mechanism discrete models of the bed mobile phase for different components may include:

[0013] The dimensionless axial spatial coordinates of each bed corresponding to the dynamic mechanism model of the bed mobile phase are divided into NE finite elements;

[0014] The first-order discretization matrix and the second-order discretization matrix are derived using the Legendre orthogonal polynomial of order NP with the definition interval [0,1];

[0015] Based on the first-order discretization matrix and the second-order discretization matrix, the dynamic mechanism model of the bed mobile phase on each finite element is discretized to obtain the dynamic mechanism discrete models of the bed mobile phase for different components.

[0016] Optionally, the discretization of the dynamic mechanism model of the bed stationary phase based on the orthogonal collocation method to obtain the dynamic mechanism discrete models of the bed stationary phase for different components may include:

[0017] Based on ρ 2 The first-order discretization matrix and the second-order discretization matrix derived from the Jacobi orthogonal polynomial of order (2×NPR);

[0018] Based on the first-order discretization matrix and the second-order discretization matrix, the dynamic mechanism model of the bed stationary phase is discretized to obtain the dynamic mechanism discrete models of the bed stationary phase for different components.

[0019] Optionally, in the dynamic mechanism model of the bed fixed phase, the adsorption amounts of different components on the adsorbent are determined by a multi-component non-linear competitive adsorption isotherm.

[0020] Optionally, the multi-component non-linear competitive adsorption isotherm is a modified multi-component Langmuir adsorption isotherm with dual selective adsorption centers;

[0021] Among them, the dual selective adsorption centers include: an aromatic selective adsorption center and a non-aromatic selective adsorption center.

[0022] Optionally, based on the axial dispersion coefficient and the film mass transfer coefficient in the kinetic parameters of different components, a dynamic mechanism model of the bed mobile phase for different components is constructed.

[0023] Optionally, based on the intra-particle diffusion coefficient in the kinetic parameters of different components, a dynamic mechanism model of the bed fixed phase for different components is constructed.

[0024] In a second aspect, an embodiment of the present invention provides a modeling device for a diesel aromatic simulated moving bed adsorption separation device, which may include:

[0025] A bed dynamic mechanism model construction module, configured to respectively construct a dynamic mechanism model of the bed mobile phase and a dynamic mechanism model of the bed fixed phase for different components divided by the aromatic components, non-aromatic components, and desorbent components in the diesel based on the material balance principle and the mass transfer mechanism;

[0026] A discretization processing module, configured to perform discretization processing on the dynamic mechanism model of the bed mobile phase based on the finite element method and the orthogonal collocation method to obtain a discrete model of the dynamic mechanism of the bed mobile phase for different components; and perform discretization processing on the dynamic mechanism model of the bed fixed phase based on the orthogonal collocation method to obtain a discrete model of the dynamic mechanism of the bed fixed phase for different components;

[0027] A node model construction module, configured to respectively construct node models for different components based on the material balance principle; wherein, the node models include: an injection node model, an extract node model, a desorbent node model, and a raffinate node model;

[0028] A bed dynamic mechanism discrete model construction module, configured to construct a discrete model of the bed dynamic mechanism for different components based on the discrete model of the bed mobile phase dynamic mechanism, the discrete model of the bed fixed phase dynamic mechanism, and the node models;

[0029] A full-component bed dynamic mechanism discrete model construction module, configured to construct a discrete model of the full-component bed dynamic mechanism of the diesel aromatic simulated moving bed adsorption device based on the discrete models of the bed dynamic mechanism for different components;

[0030] An optimization module for optimizing the model parameters of the diesel aromatic simulated moving bed adsorption device based on the full-component bed layer dynamic mechanism discrete model.

[0031] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the modeling method of the diesel aromatic simulated moving bed adsorption separation device as described in the first aspect.

[0032] In a fourth aspect, an embodiment of the present invention provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the modeling method of the diesel aromatic simulated moving bed adsorption separation device as described in the first aspect.

[0033] The beneficial effects of the above technical solutions provided by the embodiments of the present invention at least include:

[0034] The embodiment of the present invention provides a modeling method and device for a diesel aromatic simulated moving bed adsorption separation device. This method can comprehensively, systematically, and accurately reveal the quantitative relationships among numerous bed layer parameters, operating parameters, kinetic parameters, adsorption isotherms, feed composition parameters, desorbent composition parameters, and device performance indicators of the diesel aromatic simulated moving bed adsorption separation device, thereby realizing the optimized design and optimized operation of the diesel aromatic simulated moving bed adsorption separation device, and having important industrial application value.

[0035] Other features and advantages of the present invention will be described in the subsequent description, and part of them will become obvious from the description or be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures specifically pointed out in the written description and the drawings.

[0036] The technical solutions of the present invention will be further described in detail below through the drawings and embodiments. Description of the Drawings

[0037] The drawings are used to provide a further understanding of the present invention, and constitute a part of the description. They are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0038] Figure 1 is a schematic diagram of the industrial device for diesel aromatic simulated moving bed adsorption separation provided in the embodiment of the present invention;

[0039] Figure 2 is a flowchart of the modeling method of the diesel aromatic simulated moving bed adsorption separation device provided in the embodiment of the present invention;

[0040] Figure 3It is a schematic structural diagram of a modeling device for a diesel aromatic simulated moving bed adsorption separation device provided in an embodiment of the present invention. Detailed implementation manners

[0041] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0042] The diesel aromatic simulated moving bed adsorption separation device in the embodiment of the present invention is used to separate aromatics and non-aromatics in diesel. Since the operating parameters of the diesel aromatic simulated moving bed adsorption separation device directly affect the device performance indicators, how to optimize the design and operation of the diesel aromatic simulated moving bed adsorption separation device is a technical problem that those skilled in the art urgently need to solve. In view of the above technical problems, a modeling method and device for a diesel aromatic simulated moving bed adsorption separation device are provided in the embodiment of the present invention.

[0043] A modeling method for a diesel aromatic simulated moving bed adsorption separation device is provided in the embodiment of the present invention. Referring to Figure 1 as shown, the diesel aromatic simulated moving bed adsorption device may include: a plurality of bed layers, adjacent bed layers are sequentially connected along the flow direction of the bed layer mobile phase, sampling nodes, extract nodes, desorbent nodes and raffinate nodes are arranged between the bed layers, and the nodes move synchronously to the next bed layer along the flow direction of the bed layer mobile phase according to the step time to realize the simulated moving operation of the diesel aromatic simulated moving bed adsorption separation device on the bed layers.

[0044] The bed layer parameters of the above diesel aromatic simulated moving bed adsorption device in the embodiment of the present invention may include the total number of bed layers, the number of bed layers in zone one, the number of bed layers in zone two, the number of bed layers in zone three, the number of bed layers in zone four, the bed layer diameter, the bed layer height, the bed layer porosity, the adsorbent radius; the operating parameters include the step time, the sampling flow rate, the extract flow rate, the raffinate flow rate, the desorbent flow rate, the flow rate in zone one, the flow rate in zone two, the flow rate in zone three, the flow rate in zone four; the kinetic parameters include the axial dispersion coefficient, the film mass transfer coefficient, the intra-particle diffusion coefficient; the adsorption isotherm is a multi-component non-linear competitive adsorption isotherm; the feed composition parameters include the concentration of complex aromatic components and the concentration of complex non-aromatic components in diesel; the desorbent composition parameters include the concentration of strong desorbent and the concentration of weak desorbent.

[0045] The inventor divides the complex components of aromatics in diesel into at least 3 lumped components, which may include total monocyclic aromatics, total bicyclic aromatics, and total tricyclic aromatics; divides the complex components of non-aromatics in diesel into at least 2 lumped components, which may include total paraffins and total naphthenes; divides the components of the desorbent into at least 2 components, including a strong desorbent and a weak desorbent; the components involved in the modeling method in this embodiment are at least 7 components, including total monocyclic aromatics, total bicyclic aromatics, total tricyclic aromatics, total paraffins, total naphthenes, strong desorbent, and weak desorbent; the feed includes aromatics and non-aromatics in diesel, and enters the device through the feed node; the desorbent enters the device through the desorbent node; the extract rich in aromatics exits the device through the extract node; the raffinate rich in non-aromatics exits the device through the raffinate node; the total number of beds in the above device is between 4 and 48, and the beds are connected along the flow direction of the bed mobile phase. The beds located between the feed node and the raffinate node are defined as the first-zone beds, the beds located between the extract node and the feed node are defined as the second-zone beds, the beds located between the desorbent node and the extract node are defined as the third-zone beds, and the beds located between the raffinate node and the desorbent node are defined as the fourth-zone beds; the feed node, extract node, desorbent node, and raffinate node all move synchronously to the next bed at the rhythm of the step time along the flow direction of the bed mobile phase, so as to realize the simulated moving operation of the device on the beds.

[0046] Refer to Figure 1 As shown, in the embodiment of the present invention, the total number of beds is 12 and is configured in four zones as follows: the number of beds in the fourth zone is 2, the number of beds in the third zone is 3, the number of beds in the second zone is 3, and the number of beds in the first zone is 4. Therefore, the model established by the above modeling method in the embodiment of the present invention includes 12 bed models, and each bed model includes a bed mobile phase model and a bed stationary phase model. The volume of the bed mobile phase is the product of the bed volume and the bed porosity; the volume of the bed stationary phase is the volume of the adsorbent in the bed.

[0047] Refer to Figure 2 As shown, the modeling method provided in the embodiment of the present invention may include the following steps:

[0048] Step S21: Based on the material balance principle and the mass transfer mechanism, respectively construct the bed mobile phase dynamic mechanism model and the bed stationary phase dynamic mechanism model of different components divided by the aromatics component, non-aromatics component, and desorbent component in diesel.

[0049] The bed mobile phase dynamic mechanism model constructed in this embodiment can be expressed by a system of partial differential equations as follows:

[0050]

[0051] Where, c jis the concentration of the j-th component in the mobile phase of the bed; c Pj is the liquid phase concentration of the j-th component in the pores of the adsorbent; t is time; L is the bed height; x is the dimensionless axial space coordinate of the bed; R P is the adsorbent radius; ρ is the dimensionless radial space coordinate of the adsorbent; ε is the bed porosity; u is the interstitial velocity of the mobile phase, u = Q / (επd 2 / 4), where Q is the flow rate in the area where the bed is located and d is the bed diameter; D Lj is the axial dispersion coefficient of the j-th component; k Fj is the film mass transfer coefficient of the j-th component.

[0052] In this embodiment, the estimation formula for the axial dispersion coefficient D Lj of the above-mentioned j-th component is:

[0053] The estimation formula for the film mass transfer coefficient k Fj of the above-mentioned j-th component is:

[0054] where, Re is the Reynolds number, Re = 2R P ρu / μ; R P is the adsorbent radius; ρ is the density of the mobile phase; u is the interstitial velocity of the mobile phase; ε is the viscosity of the mobile phase.

[0055] The dynamic mechanism model of the bed stationary phase constructed in this embodiment can be represented by a system of partial differential equations as follows:

[0056]

[0057] where, q j is the adsorption amount of the j-th component on the adsorbent, which is calculated using the multi-component non-linear competitive adsorption isotherm; D Pj is the intra-particle diffusion coefficient of the j-th component.

[0058] The estimation formula for the intra-particle diffusion coefficient D Pj of the above-mentioned j-th component is:

[0059] where, ε P is the adsorbent porosity; D Mj is the molecular diffusion coefficient of the j-th component.

[0060] Step S22: Discretize the dynamic mechanism model of the bed mobile phase based on the finite element method and the orthogonal collocation method to obtain the discrete model of the dynamic mechanism of the bed mobile phase for different components.

[0061] In the implementation of this step, first, the dimensionless axial spatial coordinates of each bed layer corresponding to the bed layer mobile phase dynamic mechanism model are divided into NE finite elements; then, the first-order discretization matrix and the second-order discretization matrix are derived using the Legendre orthogonal polynomials of order NP with the defined interval [0,1]; finally, based on the first-order discretization matrix and the second-order discretization matrix, the bed layer mobile phase dynamic mechanism model on each finite element is discretized to obtain the discrete models of the bed layer mobile phase dynamic mechanism for different components.

[0062] In the specific implementation of this step, first, the dimensionless axial spatial coordinates of each bed layer are divided into NE finite elements, which are successively 0 = X 1 <X 2 …X NE <X NE+1 =1; then, the first-order discretization matrix A and the second-order discretization matrix B derived from the Legendre orthogonal polynomials of order NP defined in the interval [0,1] are used; then, based on the above discretization matrix, the partial differential equation system of the bed layer mobile phase dynamic mechanism model on each finite element is discretized, so as to obtain the discrete model of the bed layer mobile phase dynamic mechanism for the j-th component; in this embodiment, the discrete model of the bed layer mobile phase dynamic mechanism for the j-th component is a set of differential-algebraic mixed equations, which are expressed as follows:

[0063]

[0064] Step S23: Discretize the bed layer stationary phase dynamic mechanism model based on the orthogonal collocation method to obtain the discrete models of the bed layer stationary phase dynamic mechanism for different components.

[0065] This step first derives the first-order discretization matrix and the second-order discretization matrix based on the (2×NPR)-order Jacobi orthogonal polynomials of ρ 2 ; then, based on the first-order discretization matrix and the second-order discretization matrix, the bed layer stationary phase dynamic mechanism model is discretized to obtain the discrete models of the bed layer stationary phase dynamic mechanism for different components.

[0066] In the specific implementation of this step, the bed layer stationary phase dynamic mechanism model of the j-th component constructed by the orthogonal collocation discretization method is discretized; specifically as follows: use the first-order discretization matrix 2 derived from the (2×NPR)-order Jacobi orthogonal polynomials of ρ and the second-order discretization matrix to discretize the bed layer stationary phase dynamic mechanism model of the j-th component, so as to obtain the discrete model of the bed layer stationary phase dynamic mechanism for the j-th component; the discrete model of the bed layer mobile phase dynamic mechanism for the j-th component is a set of differential-algebraic mixed equations, which are expressed as follows:

[0067]

[0068] It should be noted that the above steps S22 and S23 are not executed in a specific order. It is possible to execute step S22 first and then step S23, or execute step S23 first and then step S22. Of course, the above steps S22 and S23 can also be executed simultaneously. The embodiments of the present invention do not make specific limitations on this.

[0069] Step S24: Based on the principle of material balance, node models of different components are respectively constructed; among them, the node models include: a feed injection node model, an extract node model, a desorbent node model, and a raffinate node model.

[0070] The above feed injection node model in this embodiment is a set of algebraic equations, which is expressed as follows:

[0071]

[0072] The above extract node model is a set of algebraic equations, which is expressed as follows:

[0073]

[0074] The above desorbent node model is a set of algebraic equations, which is expressed as follows:

[0075]

[0076] The above raffinate node model is a set of algebraic equations, which is expressed as follows:

[0077]

[0078] Among them, Q F is the feed injection flow rate; Q E is the extract flow rate; Q R is the raffinate flow rate; Q D is the desorbent flow rate; Q I is the flow rate in the first zone; Q II is the flow rate in the second zone; Q III is the flow rate in the third zone; Q IV is the flow rate in the fourth zone; c j,F is the concentration parameter of the j-th component in the feed composition parameter; c j,D is the concentration parameter of the j-th component in the desorbent composition parameter; c j,E is the concentration of the j-th component in the extract; c j,R is the concentration of the j-th component in the raffinate; is the concentration of the j-th component in the bed mobile phase at the inlet of the first zone; is the concentration of the j-th component in the bed mobile phase at the inlet of the second zone; is the concentration of the j-th component in the mobile phase of the bed at the entrance of the third zone; is the concentration of the j-th component in the mobile phase of the bed at the entrance of the fourth zone; is the concentration of the j-th component in the mobile phase of the bed at the exit of the first zone; is the concentration of the j-th component in the mobile phase of the bed at the exit of the second zone; is the concentration of the j-th component in the mobile phase of the bed at the exit of the third zone; is the concentration of the j-th component in the mobile phase of the bed at the exit of the fourth zone.

[0079] It should also be noted here that the above step S24 can be executed simultaneously with the above steps S21, S22, etc., or can be executed prior to them, as long as the above node model is constructed before step S25. The embodiments of the present invention do not make specific limitations on this.

[0080] Step S25: Based on the dynamic mechanism discrete model of the mobile phase of the bed, the dynamic mechanism discrete model of the stationary phase of the bed, and the node model, construct the dynamic mechanism discrete model of the bed for different components. This step constructs the dynamic mechanism discrete model of the bed for different components based on the dynamic mechanism discrete model of the mobile phase of the bed for different components obtained in step S22, the dynamic mechanism discrete model of the stationary phase of the bed for different components obtained in step S23, and the node model of different components constructed in step S24.

[0081] Step S26: Based on the dynamic mechanism discrete model of the bed for different components, construct the dynamic mechanism discrete model of the entire-component bed of the diesel aromatic simulated moving bed adsorption device. Each of the above 7 components is involved in the dynamic mechanism discrete model of the entire-component bed in this step. The dynamic mechanism discrete models of the bed for each component are combined to construct the dynamic mechanism discrete model of the entire-component bed.

[0082] Step S27: Optimize the model parameters of the diesel aromatic simulated moving bed adsorption device based on the dynamic mechanism discrete model of the entire-component bed.

[0083] The dynamic mechanism discrete model of the entire-component bed constructed in this step is a large-scale differential-algebraic mixed equation set, and the Gear method is used for solving.

[0084] The above modeling method provided in the embodiments of the present invention can comprehensively, systematically, and accurately reveal the quantitative relationships between numerous bed parameters, operating parameters, kinetic parameters, adsorption isotherms, feed composition parameters, desorbent composition parameters of the diesel aromatic simulated moving bed adsorption separation device and the device performance indicators, so as to realize the optimal design and optimal operation of the diesel aromatic simulated moving bed adsorption separation device, and has important industrial application value.

[0085] In an alternative embodiment, the adsorption amounts of different components on the adsorbent in the bed fixed-phase dynamic mechanism model are determined using a multi-component non-linear competitive adsorption isotherm.

[0086] In a specific embodiment, the multi-component non-linear competitive adsorption isotherm is a modified multi-component Langmuir adsorption isotherm with dual selective adsorption centers; wherein, the dual selective adsorption centers include: an aromatic selective adsorption center and a non-aromatic selective adsorption center.

[0087] In this embodiment, the improved multi-component Langmuir adsorption isotherm with dual selective adsorption centers is:

[0088]

[0089] wherein, q j is the adsorption amount of the j-th component on the adsorbent; c Pj is the liquid-phase concentration of the j-th component in the pores of the adsorbent; q Mj is the saturation adsorption amount of the j-th component on the aromatic selective adsorption center of the adsorbent; K j is the adsorption constant of the j-th component on the aromatic selective adsorption center of the adsorbent; is the saturation adsorption amount of the j-th component on the non-aromatic selective adsorption center of the adsorbent; is the adsorption constant of the j-th component on the non-aromatic selective adsorption center of the adsorbent.

[0090] In another alternative embodiment, a bed mobile-phase dynamic mechanism model for different components is constructed based on the axial dispersion coefficient and the film mass transfer coefficient in the kinetic parameters of different components.

[0091] In another alternative embodiment, a bed fixed-phase dynamic mechanism model for different components is constructed based on the intra-particle diffusion coefficient in the kinetic parameters of different components.

[0092] In a specific example, the scale of the diesel aromatic simulated moving bed adsorption separation device involved in the embodiments of the present invention is a super-large industrial device with an annual output of 2 million tons. Many parameters of this industrial device, such as bed parameters, operating parameters, kinetic parameters, adsorption isotherms, feed composition parameters, desorbent composition, etc., will affect the device performance indicators; among the bed parameters, the total number of beds is 12, the number of beds in zone one is 4, the number of beds in zone two is 3, the number of beds in zone three is 3, the number of beds in zone four is 2, the bed diameter is 9000 mm, the bed height is 1720 mm, the bed porosity is 0.31, and the adsorbent radius is 0.35 mm; among the operating parameters, the step time is 343.8 seconds, the injection flow rate is 257.65 m 3 / h, the extract flow rate is 254.60 m 3 / h, raffinate flow rate 431.56 m 3 / h, desorbent flow rate 428.51 m 3 / h, flow rate in the first zone 1150.37 m 3 / h, flow rate in the second zone 892.72 m 3 / h, flow rate in the third zone 1147.32 m 3 / h, flow rate in the fourth zone 718.81 m 3 / h; The kinetic parameters include axial dispersion coefficient, film mass transfer coefficient, and intra-particle diffusion coefficient; The adsorption isotherm is a multi-component non-linear competitive adsorption isotherm; The feed composition parameters include the concentrations of aromatic complex components and non-aromatic complex components in diesel; The desorbent composition parameters include the concentrations of strong desorbent and weak desorbent.

[0093] In the above step S21, the complex components of aromatics in diesel are divided into 3 lumped components, including total monocyclic aromatics, total bicyclic aromatics, and total tricyclic aromatics, and the concentrations of each lumped component are 15.20 m%, 9.70 m%, and 2.10% respectively; The complex components of non-aromatics in diesel are divided into 2 lumped components, including total paraffins and total naphthenes, and the concentrations of each lumped component are 48.70 m% and 24.30% respectively; The components of the desorbent are divided into 2 components, including strong desorbent and weak desorbent, and the concentrations of each component are 30.00 m% and 70.00% respectively. Then, based on the above steps, a dynamic mechanism model of the bed mobile phase and a dynamic mechanism model of the bed stationary phase for different components in step S21 are constructed.

[0094] The performance indicators of the diesel aromatic simulated moving bed adsorption separation industrial device mainly include two items, namely: the purity of aromatics in the extract and the purity of non-aromatics in the raffinate. The model output results of the specific embodiment 1 of the present invention are shown in Table 1, and the deviations from the performance indicators measured by the on-site industrial device are all within 1.3%. This fully shows that: the present invention can comprehensively, systematically, and accurately reveal the quantitative relationship between all these model parameters and the device performance indicators, so as to realize the optimized design and optimized operation of the device, and has important industrial application value.

[0095] Table 1 Comparison of performance indicators

[0096]

[0097] Specific embodiment 2:

[0099] Specific Embodiment 2 only changes one model parameter in Specific Embodiment 1, changing the adsorbent radius parameter from 0.35 mm to 0.70 mm; at the same time, all other model parameters, including bed parameters, operating parameters, kinetic parameters, adsorption isotherm, feed composition parameters, desorbent composition parameters, etc., are the same as those in Specific Embodiment 1 or the on-site industrial device.

[0100] Table 2 Comparison of Performance Indicators

[0101]

[0102] The model output results of Specific Embodiment 2 of the present invention, as shown in Table 2, have deviations of 10.7% and 4.3% respectively from the performance indicators measured by the on-site industrial device, accurately revealing that increasing the adsorbent radius parameter will significantly reduce the device performance indicators, which has important guiding significance for the optimal design of the device. It should be particularly noted that when those skilled in the art establish the bed stationary phase model, the existing modeling method simplifies the bed stationary phase to a homogeneous phase, that is: the component concentration is uniform in the adsorbent radius direction at any time, resulting in the existing modeling method being difficult to reflect the influence of the adsorbent radius parameter on the device performance indicators.

[0103] Based on the same inventive concept, the present invention also provides a modeling device for a diesel aromatic simulated moving bed adsorption separation device, as shown in Figure 3 The modeling device may include:

[0104] The bed dynamic mechanism model construction module 31 is used to construct the bed mobile phase dynamic mechanism models and bed stationary phase dynamic mechanism models of different components divided by the aromatic components, non-aromatic components and desorbent components in diesel based on the material balance principle and mass transfer mechanism;

[0105] The discretization processing module 32 is used to discretize the bed mobile phase dynamic mechanism model based on the finite element method and orthogonal collocation method to obtain the bed mobile phase dynamic mechanism discrete model of different components; and, discretize the bed stationary phase dynamic mechanism model based on the orthogonal collocation method to obtain the bed stationary phase dynamic mechanism discrete model of different components;

[0106] The node model construction module 33 is used to construct the node models of different components based on the material balance principle; wherein, the node models include: the injection node model, the extract node model, the desorbent node model and the raffinate node model;

[0107] The bed dynamic mechanism discrete model construction module 34 is used to construct the bed dynamic mechanism discrete models of different components based on the bed mobile phase dynamic mechanism discrete model, the bed stationary phase dynamic mechanism discrete model and the node models;

[0108] The full-component bed dynamic mechanism discrete model construction module 35 is used to construct the full-component bed dynamic mechanism discrete model of the diesel aromatic simulated moving bed adsorption device based on the bed dynamic mechanism discrete models of different components;

[0109] The optimization module 36 is used to optimize the model parameters of the diesel aromatic simulated moving bed adsorption device based on the full-component bed dynamic mechanism discrete model.

[0110] In an optional embodiment, the discretization processing module 32 is specifically configured to:

[0111] Divide the dimensionless axial space coordinates of each bed corresponding to the bed mobile phase dynamic mechanism model into NE finite elements;

[0112] Derive the first-order discretization matrix and the second-order discretization matrix by using the NP-order Legendre orthogonal polynomial with the definition interval [0,1];

[0113] Based on the first-order discretization matrix and the second-order discretization matrix, perform discretization processing on the bed mobile phase dynamic mechanism model on each finite element to obtain the bed mobile phase dynamic mechanism discrete models of different components.

[0114] In an optional embodiment, the discretization processing module 32 is also specifically configured to:

[0115] Based on the first-order discretization matrix and the second-order discretization matrix derived from the (2×NPR)-order Jacobi orthogonal polynomial of ρ 2 ;

[0116] Based on the first-order discretization matrix and the second-order discretization matrix, perform discretization processing on the bed stationary phase dynamic mechanism model to obtain the bed stationary phase dynamic mechanism discrete models of different components.

[0117] Based on the same inventive concept, an embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the modeling method of the above-mentioned diesel aromatic simulated moving bed adsorption separation device is implemented.

[0118] Based on the same inventive concept, an embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the modeling method of the above-mentioned diesel aromatic simulated moving bed adsorption separation device is implemented.

[0119] The principles of the problems solved by the above-mentioned device, medium, and related equipment in the embodiments of the present invention are similar to those of the foregoing method. Therefore, the implementation can refer to the implementation of the foregoing method, and the repeated parts will not be described again.

[0120] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0121] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices produce means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0122] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing devices to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including instruction means that implement the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0123] These computer program instructions can also be loaded onto a computer or other programmable data processing devices, such that a series of operation steps are executed on the computer or other programmable devices to generate a computer-implemented process, so that the instructions executed on the computer or other programmable devices provide steps for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0124] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A modeling method for a diesel aromatics simulated moving bed adsorption separation device, characterized in that: The diesel aromatics simulated moving bed adsorption device comprises: a plurality of bed layers, adjacent bed layers are sequentially connected along the flow direction of the mobile phase of the bed layer, injection nodes, extraction liquid nodes, desorbent nodes and residual liquid nodes are arranged between the bed layers, and the nodes are synchronously moved to the next bed layer along the flow direction of the mobile phase of the bed layer according to the step time, so as to realize the diesel aromatics simulated moving bed adsorption separation device to simulate the movement operation of the bed layer; the modeling method comprises: Based on the material balance principle and mass transfer mechanism, a bed mobile phase dynamic mechanism model and a bed stationary phase dynamic mechanism model of different components divided by aromatic components, non-aromatic components and desorbent components in the diesel are respectively constructed; Discretizing the bed mobile phase dynamic mechanism model based on the finite element method and the orthogonal collocation method to obtain a discrete model of the bed mobile phase dynamic mechanism of different components; Discretizing the bed stationary phase dynamic mechanism model based on the orthogonal collocation method to obtain discrete bed stationary phase dynamic mechanism models of different components; Based on the material balance principle, node models of different components are constructed respectively; wherein the node models include: an injection node model, an extract node model, a desorbent node model and a residual liquid node model; Based on the bed mobile phase dynamic mechanism discrete model, the bed stationary phase dynamic mechanism discrete model and the node model, constructing bed dynamic mechanism discrete models of different components; Based on the bed dynamic mechanism discrete models of different components, a full-component bed dynamic mechanism discrete model of the diesel aromatics simulated moving bed adsorption device is constructed to optimize the model parameters of the diesel aromatics simulated moving bed adsorption device based on the full-component bed dynamic mechanism discrete model.

2. The method according to claim 1, characterized in that The method of discretizing the bed mobile phase dynamic mechanism model based on the finite element method and the orthogonal collocation method to obtain a discrete model of the bed mobile phase dynamic mechanism of different components includes: Dividing the dimensionless axial spatial coordinates of each bed corresponding to the bed mobile phase dynamic mechanism model into NE finite elements; The first-order discretization matrix and the second-order discretization matrix are derived by using NP-order Legendre orthogonal polynomials with a definition interval of [0,1]. Based on the first-order discretization matrix and the second-order discretization matrix, the bed mobile phase dynamic mechanism model on each finite element is discretized to obtain the bed mobile phase dynamic mechanism discrete models of different components.

3. The method according to claim 1, characterized in that The bed stationary phase dynamic mechanism model is discretized based on the orthogonal collocation method to obtain a bed stationary phase dynamic mechanism discrete model of different components, including: Based on ρ 2 The first-order discretization matrix and the second-order discretization matrix are derived from the (2×NPR)-order Jacobian orthogonal polynomials; Based on the first-order discretization matrix and the second-order discretization matrix, the bed stationary phase dynamic mechanism model is discretized to obtain bed stationary phase dynamic mechanism discrete models of different components.

4. The method according to claim 1, characterized in that: The adsorption amounts of different components on the adsorbent in the bed stationary phase dynamic mechanism model are determined using multi-component nonlinear competitive adsorption isotherms.

5. The method according to claim 4, characterized in that The multi-component nonlinear competitive adsorption isotherm is a modified multi-component Langmuir-type adsorption isotherm with selective adsorption of dual centers; The selective adsorption dual centers include: aromatic selective adsorption centers and non-aromatic selective adsorption centers.

6. The method according to any one of claims 1 to 5, characterized in that: The dynamic mechanism models of bed mobile phases with different components are constructed according to the axial diffusion coefficient and membrane mass transfer coefficient in the kinetic parameters of different components.

7. The method according to any one of claims 1 to 5, characterized in that: The bed stationary phase dynamic mechanism models of different components are constructed according to the intraparticle diffusion coefficients in the kinetic parameters of different components.

8. A modeling device for a diesel aromatics simulated moving bed adsorption separation device, characterized in that: include: A bed dynamic mechanism model construction module is used to construct a bed mobile phase dynamic mechanism model and a bed stationary phase dynamic mechanism model of different components divided by aromatic components, non-aromatic components and desorbent components in the diesel based on the material balance principle and mass transfer mechanism; A discretization processing module is used to discretize the bed mobile phase dynamic mechanism model based on the finite element method and the orthogonal collocation method to obtain a discrete model of the bed mobile phase dynamic mechanism of different components; and, discretizing the bed stationary phase dynamic mechanism model based on an orthogonal collocation method to obtain discrete bed stationary phase dynamic mechanism models of different components; A node model construction module is used to construct node models of different components based on the material balance principle; wherein the node models include: an injection node model, an extract node model, a desorbent node model and a residual liquid node model; A bed dynamic mechanism discrete model construction module is used to construct bed dynamic mechanism discrete models of different components based on the bed mobile phase dynamic mechanism discrete model, the bed stationary phase dynamic mechanism discrete model and the node model; A full-component bed dynamic mechanism discrete model construction module is used to construct a full-component bed dynamic mechanism discrete model of the diesel aromatics simulated moving bed adsorption device based on the bed dynamic mechanism discrete models of different components; The optimization module is used to optimize the model parameters of the diesel aromatics simulated moving bed adsorption device based on the full-component bed dynamic mechanism discrete model.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the modeling method of the diesel aromatics simulated moving bed adsorption separation device according to any one of claims 1 to 7 is implemented.

10. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the modeling method of the diesel aromatics simulated moving bed adsorption separation device according to any one of claims 1 to 7 is implemented.

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