Natural gas deacidification process characterization method and device based on deacidification tower

Abstract

The invention relates to the technical field of chemical process simulation calculation, and provides a natural gas deacidification process characterization method and device based on a deacidification tower, and the method comprises the steps: coupling a pre-generated solubility model of the natural gas deacidification process with a chemical reaction equilibrium model to generate a first coupling model; coupling the chemical reaction equilibrium model with a pre-generated phase equilibrium model of the natural gas deacidification process to generate a second coupling model; generating an equilibrium constant model of the natural gas deacidification process according to the first coupling model and the second coupling model; and representing the natural gas deacidification process according to the equilibrium constant model and a pre-generated deacidification tower model of a deacidification tower. The method provided by the invention can better adapt to simulation of the natural gas deacidification process when a multi-element system and various acid gases coexist, and has better generalization.

Description

Technical Field

[0001] This application relates to the field of chemical process simulation and calculation technology, specifically to a method and apparatus for characterizing the natural gas deacidification process based on a deacidification tower. Background Technology

[0002] Currently, digital simulation methods for natural gas amine deacidification processes still have the following limitations that urgently need to be overcome: the current equilibrium constants in the deacidification reaction process cannot fully reflect the deacidification process. Specifically, the natural gas deacidification reaction involves chemical reaction processes, phase equilibrium processes, and physical dissolution processes. However, the current chemical reaction equilibrium constants and phase equilibrium constants can only describe the equilibrium of a certain chemical reaction and the equilibrium between the gas and liquid phases at a certain temperature and pressure. They do not consider the influence of solubility on the overall reaction during the reaction process, which is obviously inconsistent with the actual natural gas deacidification process. Summary of the Invention

[0003] The present application provides a method and apparatus for characterizing the natural gas deacidification process based on a deacidification tower, which aims to solve at least some of the above-mentioned technical problems.

[0004] To achieve the above objectives, firstly, this invention provides a method for characterizing the natural gas deacidification process based on a deacidification tower, comprising:

[0005] The solubility model of the pre-generated natural gas deacidification process is coupled with the chemical reaction equilibrium model to generate the first coupled model;

[0006] The chemical reaction equilibrium model is coupled with the pre-generated phase equilibrium model of the natural gas deacidification process to generate a second coupled model;

[0007] An equilibrium constant model for the natural gas deacidification process is generated based on the first coupling model and the second coupling model.

[0008] The natural gas deacidification process is characterized based on the equilibrium constant model and the pre-generated deacidification tower model.

[0009] In some embodiments of the present invention, the natural gas deacidification process is characterized according to the equilibrium constant model and the pre-generated deacidification tower model, including:

[0010] The equilibrium constant model is coupled with the deacidification tower model to generate a third coupled model;

[0011] Solve the third coupling model to characterize the natural gas deacidification process.

[0012] In some embodiments of the present invention, solving the third coupling model includes:

[0013] The third coupling model is solved using a three-layer iterative solution method; wherein:

[0014] The first layer is used to solve the chemical reaction equilibrium model. The iterative variables in the first layer solution process are the degree of reaction of the chemical reaction equilibrium model and the mole fraction of the feed components.

[0015] The second layer is used to solve the phase equilibrium model. The iterative variables in the second layer solution process are the fugacity coefficient of the gas phase and the activity coefficient of the liquid phase.

[0016] The third layer is used to solve the deacidification tower model. The iterative variables in the third layer solution process are the temperature, flow rate, and mole fraction of the components in each tray of the deacidification tower.

[0017] In some embodiments of the present invention, the step of generating the solubility model includes:

[0018] The solubility model is generated based on the pressure, Henry's law, and mole fraction of the substances during the natural gas deacidification process.

[0019] The steps for generating the chemical reaction equilibrium model include:

[0020] The chemical reaction equilibrium model is generated based on the chemical reaction equations and hydrolysis reaction equations of the substances in the natural gas deacidification process; in the chemical reaction equilibrium model, the forward reaction rate and the reverse reaction rate of the substances are equal.

[0021] In some embodiments of the present invention, the step of generating the phase equilibrium model includes:

[0022] The phase equilibrium model is generated based on the system pressure during the natural gas deacidification process, the mole fraction of the component in the gas phase, the mole fraction of the component in the liquid phase, the fugacity coefficient, the activity coefficient, the Henry coefficient, the partial molar volume of the component in water under infinite dilution, the saturated vapor pressure of pure water at the reaction temperature, and the molar volume.

[0023] In some embodiments of the present invention, the step of generating the deacidification tower model includes:

[0024] The deacidification tower model is generated based on the mass conservation equation, energy conservation equation, normalization equation, and phase equilibrium equation for each stage of the deacidification tower.

[0025] Secondly, this application provides a characterization device for natural gas deacidification process based on a deacidification tower, the device comprising:

[0026] The first coupling model generation module is used to couple the pre-generated solubility model of the natural gas deacidification process with the chemical reaction equilibrium model to generate the first coupling model;

[0027] The second coupling model generation module is used to couple the chemical reaction equilibrium model with the pre-generated phase equilibrium model of the natural gas deacidification process to generate the second coupling model.

[0028] The equilibrium constant model generation module is used to generate an equilibrium constant model for the natural gas deacidification process based on the first coupling model and the second coupling model.

[0029] The deacidification process characterization module is used to characterize the natural gas deacidification process based on the equilibrium constant model and the pre-generated deacidification tower model.

[0030] In some embodiments of the present invention, the deacidification process characterization module includes:

[0031] The third coupling model generation unit is used to couple the equilibrium constant model with the deacidification tower model to generate a third coupling model;

[0032] The third coupling model solving unit is used to solve the third coupling model to characterize the natural gas deacidification process.

[0033] In some embodiments of the present invention, the third coupling model solving unit includes:

[0034] A three-layer iterative solution unit is used to solve the third coupled model according to a three-layer iterative solution method; wherein:

[0035] The first layer is used to solve the chemical reaction equilibrium model. The iterative variables in the first layer solution process are the degree of reaction of the chemical reaction equilibrium model and the mole fraction of the feed components.

[0036] The second layer is used to solve the phase equilibrium model. The iterative variables in the second layer solution process are the fugacity coefficient of the gas phase and the activity coefficient of the liquid phase.

[0037] The third layer is used to solve the deacidification tower model. The iterative variables in the third layer solution process are the temperature, flow rate, and mole fraction of the components in each tray of the deacidification tower.

[0038] In some embodiments of the present invention, a natural gas deacidification process characterization device based on a deacidification tower further includes:

[0039] A solubility model generation module, used to generate the solubility model; the solubility model generation module includes:

[0040] A solubility model generation unit is used to generate the solubility model based on the pressure, Henry's law coefficient, and mole fraction of the substances during the natural gas deacidification process.

[0041] A chemical reaction equilibrium model generation module, used to generate the chemical reaction equilibrium model, the chemical reaction equilibrium model generation module comprising:

[0042] A chemical reaction equilibrium model generation unit is used to generate the chemical reaction equilibrium model based on the chemical reaction equations and hydrolysis reaction equations of the substances in the natural gas deacidification process; in the chemical reaction equilibrium model, the forward reaction rate and the reverse reaction rate of the substances are equal.

[0043] In some embodiments of the present invention, a natural gas deacidification process characterization device based on a deacidification tower further includes:

[0044] Phase equilibrium model generation module, used to generate the phase equilibrium model, the phase equilibrium model generation module includes:

[0045] The phase equilibrium model generation unit is used to generate the phase equilibrium model based on the system pressure during the natural gas deacidification process, the mole fraction of the component in the gas phase, the mole fraction of the component in the liquid phase, the fugacity coefficient, the activity coefficient, the Henry coefficient, the partial molar volume of the component in water under infinite dilution, the saturated vapor pressure of pure water at the reaction temperature, and the molar volume.

[0046] In some embodiments of the present invention, a natural gas deacidification process characterization device based on a deacidification tower further includes:

[0047] The deacidification tower model generation module is used to generate the deacidification tower model based on the mass conservation equation, energy conservation equation, normalization equation, and phase equilibrium equation of each stage of the deacidification tower.

[0048] Thirdly, this application provides a computer program product, including a computer program / instructions that, when executed by a processor, implement the steps of a method for characterizing a natural gas deacidification process based on a deacidification tower.

[0049] Fourthly, this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of a method for characterizing a natural gas deacidification process based on a deacidification tower.

[0050] Fifthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of a method for characterizing a natural gas deacidification process based on a deacidification tower.

[0051] As described above, this application provides a method and apparatus for characterizing a natural gas deacidification process based on a deacidification tower. The method includes: firstly, coupling a pre-generated solubility model of the natural gas deacidification process with a chemical reaction equilibrium model to generate a first coupled model; and secondly, coupling the chemical reaction equilibrium model with a pre-generated phase equilibrium model of the natural gas deacidification process to generate a second coupled model; then, generating an equilibrium constant model of the natural gas deacidification process based on the first coupled model and the second coupled model; and finally, characterizing the natural gas deacidification process based on the equilibrium constant model and the pre-generated deacidification tower model.

[0052] In summary, the natural gas deacidification process characterization method based on a deacidification tower provided in this application is better adapted to the simulation of natural gas deacidification processes in multi-component systems and when multiple acid gases coexist, and has better generalization ability. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a flowchart illustrating a method for characterizing a natural gas deacidification process based on a deacidification tower, as provided in the embodiments of this application. Figure 1 ;

[0055] Figure 2 This is a flowchart illustrating a method for characterizing a natural gas deacidification process based on a deacidification tower, as provided in the embodiments of this application. Figure 2 ;

[0056] Figure 3 This is a flowchart illustrating a method for characterizing a natural gas deacidification process based on a deacidification tower, as provided in the embodiments of this application. Figure 3 ;

[0057] Figure 4 This is a flowchart illustrating a method for characterizing a natural gas deacidification process based on a deacidification tower, as provided in the embodiments of this application. Figure 4 ;

[0058] Figure 5 This is a flowchart illustrating a method for characterizing a natural gas deacidification process based on a deacidification tower, as provided in the embodiments of this application. Figure 5 ;

[0059] Figure 6 This is a schematic flowchart of step 400 of a natural gas deacidification process characterization method based on a deacidification tower provided in an embodiment of this application;

[0060] Figure 7 This is a schematic diagram of a natural gas deacidification process characterization method based on a deacidification tower, provided as a specific application example of this application.

[0061] Figure 8 A mind map illustrating a characterization method for a natural gas deacidification process based on a deacidification tower, provided in a specific application example of this application;

[0062] Figure 9 This is a partial pressure-temperature-load relationship diagram for CO2 absorption by 2 mol / L MDEA, provided in a specific application example of this application.

[0063] Figure 10 The partial pressure-temperature-load relationship diagram for CO2 absorption by 2.94 mol / L MDEA is provided in a specific application example of this application.

[0064] Figure 11 This is a partial pressure-temperature-load relationship diagram for CO2 absorption by 4 mol / L MDEA, provided in a specific application example of this application.

[0065] Figure 12 This is a partial pressure-temperature-load relationship diagram for 2 mol / L MDEA absorbing H2S, provided in a specific application example of this application.

[0066] Figure 13 This is a partial pressure-temperature-load relationship diagram for 1 mol / L MDEA absorbing H2S in a specific application example of this application;

[0067] Figure 14 This is a schematic diagram of the structure of a natural gas deacidification process characterization device based on a deacidification tower provided in the embodiments of this application. Figure 1 ;

[0068] Figure 15 This is a schematic diagram of the structure of the deacidification process characterization module 40 provided in the embodiments of this application;

[0069] Figure 16 This is a schematic diagram of the structure of a natural gas deacidification process characterization device based on a deacidification tower provided in the embodiments of this application. Figure 2 ;

[0070] Figure 17 This is a schematic diagram of the structure of a natural gas deacidification process characterization device based on a deacidification tower provided in the embodiments of this application. Figure 3 ;

[0071] Figure 18 This is a schematic diagram of the structure of a natural gas deacidification process characterization device based on a deacidification tower provided in the embodiments of this application. Figure 4 ;

[0072] Figure 19 This is a schematic diagram of the structure of the electronic device in the embodiments of this application. Detailed Implementation

[0073] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0074] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0075] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product or device.

[0076] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0077] In natural gas extraction operations, the extracted feed gas typically contains high concentrations of acidic gas components such as carbon dioxide (CO2) and hydrogen sulfide (H2S). The presence of these components not only significantly reduces the calorific value, quality, and commercial value of natural gas, but also causes severe corrosion to metal facilities such as pipelines, valves, and storage tanks due to their reaction with water to form acidic substances (such as carbonic acid and sulfuric acid), posing a major safety hazard to the storage, transportation, and use of natural gas.

[0078] To ensure the quality and safe supply of natural gas, the amine absorption deacidification technology is widely used in industry. This technology, with its advantages of high acid gas removal efficiency, high process maturity, and relatively low overall processing cost, is widely applied to selectively remove H2S and CO2 from natural gas.

[0079] Digital oil and gas fields, a product of the deep integration of modern oil and gas industry and information technology, are centered on achieving intelligent management and control over the entire chain of oil and gas reservoir exploration, development, production, and gathering and transportation, as well as the entire lifecycle of related assets, through continuous digital monitoring, data acquisition, and visualization simulation technologies. Their goal is to significantly optimize operational processes, improve asset utilization efficiency and management decision-making, enhance health, safety, and environmental performance, and ultimately maximize asset value. In this comprehensive digital and intelligent transformation process, constructing high-fidelity and predictable digital simulation models for the most critical acid removal process unit in natural gas purification has become an indispensable and fundamental core component.

[0080] However, in addition to the technical problems described in the background section of this application, current digital simulation methods for natural gas amine deacidification processes still have the following limitations that urgently need to be overcome:

[0081] (1) Insufficient consideration of the combination of chemical reaction and tower model in the deacidification process: For the digital simulation of the natural gas amine deacidification process, the common methods are the equilibrium stage method or the reaction rate method. The equilibrium stage method mainly focuses on solving the tower model, while the reaction rate method mainly focuses on solving the chemical reaction. However, the actual deacidification process involves both chemical reaction and mass transfer between towers. Therefore, the current solution method does not adequately consider the deacidification process, resulting in deviation from the actual process.

[0082] (2) Insufficient consideration of the coexistence of ions and molecules in the medium: During the deacidification process, the gas phase mainly consists of natural gas and acidic gases, while the liquid phase contains amine molecules and a large number of ions generated during the reaction. Currently, the main methods for solving phase equilibrium are... Fahe Neither of these two methods considers the mismatch in solving the fugacity coefficient or activity coefficient of the gas-liquid phase when ions and molecules coexist. This leads to errors in solving the ion activity coefficient, causing the numerical simulation results to be inconsistent with reality.

[0083] (3) Insufficient consideration of selective absorption of multiple acidic gases: The current calculation model for natural gas deacidification process only considers the chemical reaction rate between substances. However, if multiple acidic gases are present in the solution at the same time, there may be selective absorption between the various acidic gases and the deacidification solution. That is, the absorption rate of the acidic gas first will affect the absorption rate of the remaining acidic gases. In other words, the current method does not adequately consider this reaction process.

[0084] To address at least some of the aforementioned technical problems, embodiments of this application provide a specific implementation of a method for characterizing a natural gas deacidification process based on a deacidification tower. See [link to relevant documentation]. Figure 1 The method specifically includes the following:

[0085] Step 100: Couple the solubility model of the pre-generated natural gas deacidification process with the chemical reaction equilibrium model to generate the first coupled model;

[0086] Step 200: Couple the chemical reaction equilibrium model with the pre-generated phase equilibrium model of the natural gas deacidification process to generate a second coupled model;

[0087] Step 300: Generate an equilibrium constant model for the natural gas deacidification process based on the first coupling model and the second coupling model;

[0088] Step 400: Characterize the natural gas deacidification process based on the equilibrium constant model and the pre-generated deacidification tower model.

[0089] The method provided in this application is better suited for simulating natural gas deacidification processes in multi-component systems and when multiple acid gases coexist, and has better generalization ability.

[0090] In some embodiments of the present invention, the chemical reaction equilibrium model in step 100 includes the chemical reactions and hydrolysis reactions of all substances in the deacidification process, and the reaction equilibrium is reached when the forward reaction rate and the reverse reaction rate of each chemical reaction are equal.

[0091] In some embodiments of the present invention, the fugacity coefficients of the gas phase components in the phase equilibrium model (gas-liquid phase) of step 200 are solved using the PR equation, and the activity coefficient equations of the liquid phase are solved using the e-NRTL equation. For ionic components that exist in the liquid phase but are almost non-existent in the gas phase, their mole fractions are solved using only the chemical equilibrium equation, and the thermodynamic calculations of ions in the solution are not considered in the above process; only reaction kinetics are considered.

[0092] In some embodiments of the present invention, during the calculation process in step 300, the dissolution process is considered regardless of the reaction rate. If the reaction rate is fast, the solubility is high, and if the reaction rate is slow, the solubility is low.

[0093] In some embodiments of the present invention, the deacidification tower model of step 400 assumes that each tray is in reaction equilibrium.

[0094] In some embodiments of the present invention, see Figure 2 A method for characterizing the natural gas deacidification process based on a deacidification tower, further comprising:

[0095] Step 500: Generate the solubility model. Step 500 includes:

[0096] The solubility model is generated based on the pressure, Henry's law, and mole fraction of the substances during the natural gas deacidification process.

[0097] Specifically, in the range of dilute solutions, the mathematical expression of the solubility model is shown in formula (1):

[0098] P i =H i x i (1)

[0099] Where P represents the partial pressure of substance i (kPa); H represents the Henry's coefficient of substance i (kPa); and x represents the mole fraction of substance i. The Henry's coefficient can generally be obtained by fitting experimental data.

[0100] In some embodiments of the present invention, see Figure 3 A method for characterizing the natural gas deacidification process based on a deacidification tower, further comprising:

[0101] Step 600: Generate the phase equilibrium model. Step 600 includes:

[0102] The phase equilibrium model is generated based on the system pressure during the natural gas deacidification process, the mole fraction of the component in the gas phase, the mole fraction of the component in the liquid phase, the fugacity coefficient, the activity coefficient, the Henry coefficient, the partial molar volume of the component in water under infinite dilution, the saturated vapor pressure of pure water at the reaction temperature, and the molar volume.

[0103] Specifically, the gas-liquid phase equilibrium model combined with the Henry coefficient is shown in Equation (2):

[0104]

[0105] Among them, y i This represents the mole fraction of component i in the gas phase; The corresponding fugacity coefficient is represented by PR equation of state; P represents system pressure in kPa; x i γ represents the mole fraction of component i in the liquid phase; i H represents the activity coefficient of component i. i V represents the Henry coefficient of component i. i,w This represents the partial molar volume of component i in water under infinite dilution conditions; The saturated vapor pressure of pure water at the reaction temperature, in kPa. Let m be the molar volume of pure water at the reaction temperature. 3 / mol.

[0106] The Henry coefficient is calculated using the following formula (3):

[0107] H i =A + Bcos(DT) + Csin(DT) (3)

[0108] Where A, B, C, and D are all fitting coefficients for the experimental data.

[0109] The fugacity coefficient of the gas phase is shown in equation (4) below:

[0110]

[0111] Among them, f i Indicates the gas phase fugacity coefficient; x i represents the mole fraction of the substance; p represents the partial pressure of the substance, in kPa. The remaining parameters are the mixing rule parameters of the PR equation.

[0112] The activity coefficient of the liquid phase is given by formula (5) as follows:

[0113]

[0114] in, Represents the activity coefficient of component i; This indicates the influence of the long-range activity coefficient term between components; Indicates Born's correction term; This indicates the effect of the short-range term.

[0115] In some embodiments of the present invention, see Figure 4 A method for characterizing the natural gas deacidification process based on a deacidification tower, further comprising:

[0116] Step 700: Generate the chemical reaction equilibrium model. Step 700 includes:

[0117] The chemical reaction equilibrium model is generated based on the chemical reaction equations and hydrolysis reaction equations of the substances in the natural gas deacidification process; in the chemical reaction equilibrium model, the forward reaction rate and the reverse reaction rate of the substances are equal.

[0118] Based on the above, step 100 includes:

[0119] For a given chemical reaction equation, a chemical reaction equilibrium constant is established. Taking MDEA solution with acidic gases CO2 and H2S as an example, the following equations (6)-(7) are used for illustration:

[0120]

[0121] Where aq represents CO2 and H2S physically dissolved in MDEA aqueous solution. Based on the above chemical reaction equations, the expressions for the chemical reaction equilibrium constants (8) and (9) can be derived:

[0122]

[0123] Where C represents molar concentration, mol / L. In dilute aqueous solution reactions, the amount of water consumed or generated is extremely small compared to the total amount of water, and the change in water concentration can be ignored. Therefore, the concentration of the pure liquid is not included in the expression for the equilibrium constant. Rewriting the above equation yields equations (10)-(11):

[0124]

[0125] Based on the above, acid gas load is introduced, as shown in equations (12)-(14):

[0126]

[0127] By changing the molar concentration in equations (10) and (11) to molar fraction, and based on the relationship between molar fraction and acid load, the following equations (15) to (16) are derived:

[0128]

[0129] Using Henry's Law to describe the physical dissolution process, we can derive the following equations (17) to (18):

[0130]

[0131] Among them, P i Indicates partial pressure, kPa; H i This represents the Henry coefficient, expressed in kPa.

[0132] Based on the above equations, the expressions for the partial pressures of acidic gases can be derived as shown in equations (19) to (20):

[0133]

[0134] Based on the assumption of reaction decomposition, the reaction process is divided into two stages: the acidic gas first undergoes physical dissolution, followed by a chemical reaction. Henry's Law can then be used to describe the physical dissolution stage.

[0135] Based on this, the chemical reaction equilibrium constant is further combined with the Henry coefficient to define an equilibrium constant, as shown in equations (21) to (22):

[0136]

[0137] Therefore, the general expression (23) for the equilibrium constant can be obtained as follows:

[0138]

[0139] In some embodiments of the present invention, the equilibrium constant shown in formula (23) does not take into account the phase equilibrium process. Therefore, it is necessary to further combine the equilibrium constant with the phase equilibrium equation to obtain a final new equilibrium constant model. That is, step 200 includes:

[0140] Assume the total number of species in the system is N, N = N m +N c +N a N m The number of components representing molecular types, N c Represents the number of cations, N a This represents the number of anions. There are a total of M ionization or hydrolysis reactions in the system, involving the following equations:

[0141] Material balance: The material balance of ionic reactions is represented by the degree of reaction ξ.

[0142]

[0143] Among them, F in,i ,F out,i v represents the molar flow rate of component i before and after the reaction, in mol / h; i,j It indicates the rate of a chemical reaction.

[0144] Reactant balance equation:

[0145] Fz i =Lx i +Vy i (25)

[0146] Where F represents the inflow rate, mol / h; z i Indicates the incoming component; L represents the liquid flow rate, mol / h; x i Indicates liquid phase composition; V represents gas phase flow rate, mol / h; y i Indicates gas phase components.

[0147] The gas-liquid phase equilibrium constant is calculated according to the following formula (26):

[0148]

[0149] in, Represents the gas-phase fugacity coefficient; v i,j Represents the liquid phase activity coefficient; v i,j Pressure is expressed in kPa.

[0150] The relationship between chemical equilibrium and phase equilibrium is expressed by the following equation (27):

[0151]

[0152] In phase equilibrium calculations, the gas phase fraction is defined as:

[0153]

[0154] Introducing the mole fraction after a chemical reaction:

[0155]

[0156] Substituting this into equation (26) and simplifying, we get:

[0157]

[0158] Substituting the above equation into the normalized equation, we get the following:

[0159]

[0160] We obtain the following formula:

[0161]

[0162] Substituting equation (28) into equation (25) yields the relationship between chemical equilibrium and phase equilibrium:

[0163]

[0164] Based on this, the relationship between the above chemical equilibrium equations and solubility, as shown in equations (21) and (22), is combined with equation (31) to obtain a new equilibrium constant:

[0165]

[0166] Where, γ i K represents the activity coefficient of component i; i H represents the phase equilibrium constant of component i; i K represents the Henry's coefficient of component i; R This represents a chemical reaction constant.

[0167] In some embodiments of the present invention, see Figure 5 A method for characterizing the natural gas deacidification process based on a deacidification tower, further comprising:

[0168] Step 800: Generate the deacidification tower model. Step 800 includes:

[0169] The deacidification tower model is generated based on the mass conservation equation, energy conservation equation, normalization equation, and phase equilibrium equation for each stage of the deacidification tower.

[0170] Specifically, the equilibrium stage model of the tower includes the mass conservation equation, energy conservation equation, normalization equation, and phase equilibrium equation for each stage, as shown in the following equation:

[0171] The M-equations are used to represent the material balance for each component, with each level consisting of i equations.

[0172] M i,j =F j z i,j +V j+1 y i,j+1 -(V j y i,j +L j x i,j )=0 j=1 (35)

[0173] M i,j =F j z i,j +V j+1 y i,j+1 +L j-1 x i,j-1 -(V j y i,j +L j x i,j )=0 2≤j≤N-1 (36)

[0174] M i,j =F j z i,j +L j-1 x i,j-1 -(V j y i,j +L j x i,j )=0 j=N (37)

[0175] Equation (35) applies to the first stage tray, equation (36) applies to the second to N-1th stage trays, and equation (37) applies to the last stage tray. In the equations, F represents the tray feed stream, which can be a single stream or a double stream, and can simultaneously represent both gas and liquid phase feed. i This indicates the molar composition of the feed.

[0176] E equations are used to represent the phase equilibrium relationship of each component, with i equations per level, as shown in equation (38).

[0177] E i,j =y i,j -K i,j x i,j =0 (38) The S equation is used to represent the sum of the mole fractions of each tray. There are two equations for each stage, see equation (39) and equation (340).

[0178]

[0179] The H equation is used to represent energy balance, with one equation for each level, neglecting changes in kinetic and potential energy.

[0180]

[0181] In the formula, L j V represents the downward flow rate of the liquid phase on the j-th stage tray, in kmol / h; j F represents the upward flow rate of the gas phase on the j-th stage tray, in kmol / h; j x represents the feed stream on the j-th stage tray, in kmol / h; i,j y represents the mole fraction of liquid component i on the j-th stage plate; i,j K represents the mole fraction of gaseous component i on the j-th stage plate. i,j Q represents the phase equilibrium constant of the j-th order component i; j This represents the total heat of reaction on the j-th stage plate; This represents the enthalpy change of the liquid phase on the j-th stage tray; ΔH represents the liquid phase enthalpy change on the j-th stage tray; Rj This represents the heat of reaction on the j-th stage plate.

[0182] In some embodiments of the present invention, see Figure 6 Step 400 includes:

[0183] Step 401: Couple the equilibrium constant model with the deacidification tower model to generate a third coupled model;

[0184] Specifically, the phase equilibrium relationship in the tower model is derived from the equilibrium constant of the above deacidification reaction to obtain the following equation (42), which serves as the E equation for the tower model calculation:

[0185]

[0186] Due to the presence of chemical reactions, there is also a charge balance in each tray. Taking the MDEA-H2O-CO2-CH4 quaternary system as an example, it is shown in equation (43):

[0187]

[0188] And the MDEA material conservation equation is shown in equation (44):

[0189]

[0190] The carbon conservation equation is shown in equation (45):

[0191]

[0192] The solution for tray efficiency is given by equation (46):

[0193]

[0194] in, y is the actual mole fraction of the gas phase component output by the j-th plate; i,j It is the mole fraction of the gas phase component output by the j-th plate theory; y i,j+1 It is the mole fraction of the gas phase component theoretically output from the (j+1)th plate; V j V j+1 These represent the gas phase flow rates of the j-th and (j+1)-th plates, respectively; h represents the stage height (m); a represents the mass transfer area (m). 2 G' and L' represent the rates of the gas and liquid phases, respectively, in m / s; λ represents the stripping factor; k G ,k L ρ represents the mass transfer coefficient between gases and liquids. G ,ρ L These represent the densities of the gas and liquid phases, respectively, in kg / m³. 3 E represents the enhancement factor. All of the above parameters can be solved using their respective models.

[0195] It should be noted that the mole fractions of ions and molecules can also be determined by solving the third coupling model.

[0196] Step 402: Solve the third coupling model to characterize the natural gas deacidification process.

[0197] In some embodiments of the present invention, solving the third coupling model in step 402 includes:

[0198] The third coupled model is solved using a three-layer iterative solution method; wherein: the first layer is used to solve the chemical reaction equilibrium model, and the iterative variables of the first layer solution process are the degree of reaction of the chemical reaction equilibrium model and the mole fraction of the feed components; the second layer is used to solve the phase equilibrium model, and the iterative variables of the second layer solution process are the fugacity coefficient of the gas phase and the activity coefficient of the liquid phase; the third layer is used to solve the deacidification tower model, and the iterative variables of the third layer solution process are the temperature, flow rate, and mole fraction of the components of each tray of the deacidification tower.

[0199] Specifically, a three-layer iterative solution is used to obtain the deacidification process of the natural gas deacidification tower. The first layer solves for each chemical reaction, the second layer solves for the gas-liquid phase equilibrium, and the third layer solves for the tower model. In the first layer, the iteration variables are the degree of reaction at chemical equilibrium and the feed composition. The convergence condition for the second layer is that the phase equilibrium constant meets the error requirement, and the iteration variables are the gas phase fugacity coefficient and the liquid phase activity coefficient. The convergence condition for the third layer is that the calculated temperature of each tray meets the error requirement, and the iteration variables are the temperature of each tray, the flow rate, and the mole fraction of the components. The model solution process will be briefly explained below:

[0200] (1) Initialization parameters: Initial feed F i,j and composition z i,j Temperature T j Pressure P j Number of trays N, assuming phase equilibrium constant K i Initial value, assuming activity coefficient γ i,j The initial value is 1, assuming the gas phase fraction e = 0.5, and the cutoff variable T is given. j V j .

[0201] (2) Calculate the reaction equilibrium constant K based on the temperature correlation equation. Rij Determine whether the reaction equilibrium constant has converged. If convergence is achieved, the first iteration is complete; otherwise, the reaction extent and feed composition are updated, and the reaction equilibrium constant is recalculated. The maximum iteration value is set to 1000 times.

[0202] (3) Calculate the gas phase fugacity coefficient using the PR equation and update the phase equilibrium constant K. ij Determine whether the phase equilibrium condition is met. If convergence is achieved, the second iteration is complete; otherwise, the phase equilibrium constant is recalculated. The maximum iteration value is set to 1000.

[0203] (4) Calculate the new equilibrium constant K based on the phase equilibrium constant and the chemical equilibrium constant. j .

[0204] (5) Calculate the liquid phase mole fraction x using the Thomas method ij .

[0205] (6) Calculate the gas phase volume V using the flow rate summation method j and liquid volume flow rate L j .

[0206] (7) Update the mole fraction y of the gas phase component according to the new equilibrium constant. ij .

[0207] (8) Find the efficiency h of each plate. j Calculate the actual mole fraction y of the gas phase component for each plate. ij .

[0208] (9) Calculate the temperature values ​​for each plate. Determine whether the temperature requirements for each plate are met; the convergence condition is... If convergence is achieved, the calculation ends, and the values ​​of temperature, pressure, component mole fraction, and flow rate of each plate are output. If the calculation does not converge, the values ​​of temperature, flow rate, and component mole fraction of each plate are updated and the calculation is returned to step (1). At the same time, the maximum iteration value is set to 1000 times.

[0209] The present invention has the following beneficial effects: First, the present invention proposes a new equilibrium constant model, which combines a chemical reaction equilibrium model, a physical solubility model, and a gas-liquid phase equilibrium model to derive and construct a new equilibrium constant model. The model can represent the deacidification reaction process relatively completely.

[0210] Secondly, this invention combines the tower model with the chemical reaction of the deacidification process by replacing the equilibrium constant in the phase equilibrium model in the equilibrium stage model with a new equilibrium constant model.

[0211] Finally, this invention employs a method that calculates phase equilibrium constants separately for ions and molecules, simplifying the thermodynamic model for ion solutions. For molecules present in both the gas and liquid phases, the phase equilibrium constant is solved using activity coefficient or fugacity coefficient models; for ions not present in the gas phase, the chemical equilibrium constant is used. Based on these innovations, a digital twin simulation of a natural gas desulfurization tower is achieved.

[0212] To further illustrate this solution, this application also provides a specific application example of a characterization method for natural gas deacidification processes based on a deacidification tower, see [link to relevant documentation]. Figure 7 as well as Figure 8 Specifically, it includes the following content.

[0213] Terminology Explanation:

[0214] Natural gas deacidification: Natural gas contains a large amount of acidic gases, such as carbon dioxide and hydrogen sulfide. These acidic gases react with water to form highly corrosive acidic substances, thus requiring natural gas deacidification treatment. Common deacidification processes include physical adsorption, chemical absorption, and membrane separation, among which amine deacidification is the most common.

[0215] Selective absorption: When multiple acidic gases are present in natural gas, the absorption reaction of the deacidification solution is selective for different acidic gases. Some acidic gases react quickly, such as H2S, while others react more slowly, such as CO2. The selectivity of the absorption process will determine the reaction rate.

[0216] Gas-liquid phase equilibrium: A dynamic equilibrium state reached by two phases of matter, gas and liquid, under the same temperature and pressure in a closed system. At this point, the substances transform into each other at equal rates, and the composition and quantity of the two phases no longer change with time.

[0217] Chemical equilibrium: In a closed system, the rate of the forward reaction of a reversible chemical reaction is equal to the rate of the reverse reaction. At this point, the concentrations of reactants and products no longer change net, indicating that chemical equilibrium has been reached. It is quantitatively described by the equilibrium constant K (which depends only on temperature).

[0218] Tower equilibrium stage model: The tower equilibrium stage model (also known as the equilibrium stage model, theoretical plate model, or ideal stage model) is a core theoretical framework used for analysis and design in chemical separation processes (especially tower equipment such as distillation, absorption, extraction, and stripping). It is based on a key simplifying assumption: at each stage (called an equilibrium stage or theoretical plate), the departing gas phase and liquid phase are in phase equilibrium.

[0219] Equilibrium constant: The equilibrium constant is a quantitative measure of the relationship between the concentrations (or partial pressures) of reactants and products when a chemical reaction or phase equilibrium system reaches equilibrium. It reflects the extent of the reaction or the equilibrium position and is strictly defined by the laws of thermodynamics.

[0220] Step S1: Establish chemical reaction equilibrium model, physical solubility model and phase equilibrium model for the deacidification process respectively.

[0221] Step S2: Establish an equilibrium constant model based on the chemical reaction equilibrium model, physical solubility model, and phase equilibrium model.

[0222] Step S3: Establish a deacidification tower model.

[0223] Step S4: Based on the chemical reaction equilibrium model, physical solubility model, and phase equilibrium model, the equilibrium constant model is coupled with the equilibrium stage model to perform a digital twin simulation of the deacidification tower.

[0224] This step combines thermodynamic equilibrium, reaction kinetics, and the plate equation. By establishing a new equilibrium constant, it establishes a connection between the reaction process and the plate solution process, thus achieving the coupling of the chemical process and the physical mass transfer process.

[0225] In steps S1 to S4, the chemical reaction equilibrium model, solubility model, equilibrium constant model, and deacidification tower model are first initialized, along with the gas phase fraction and reaction equilibrium constant. New equilibrium constants are calculated, and it is determined whether the chemical reaction has converged. The gas phase fraction is updated to determine whether the phase equilibrium has converged, and the phase equilibrium constant and the new equilibrium constant are updated. The gas phase flow rate V of each tray is then set. j and tray temperature T j As a cutoff variable.

[0226] First, assume a set of cut-off V j and T j The initial value of y is calculated from the bottom of the absorber upwards using a specified gas-phase feed. Then, the Thomas method is used to solve the MES equations, which are transformed into tridiagonal matrix form, to obtain y. i,j The value of y. Then calculate the value of y. i,j Substitute into the established thermodynamic model and solve for x. i,j In this step, instead of normalizing, the liquid flow rate L per tray is calculated using the flow rate summation equation. j New value, corresponding The value can be obtained through total material balance, and the stage temperature T can be obtained by solving the simultaneous energy equations of stage N. j A new set of values ​​is obtained, and the temperature difference between this time step and the previous time step of each plate is analyzed for error. After the condition is met, the loop calculation is exited, and the temperature, gas-liquid phase flow rate and molar composition are output.

[0227] Example results:

[0228] This calculation process was applied to the MDEA-H2O-CO2-H2S-CH4 pentagonal system to establish the chemical equilibrium equation, phase equilibrium equation, MESH equilibrium stage model, charge conservation equation, and ion conservation equations for the pentagonal system reaction. The compositions of natural gas and MDEA in this system are shown in Table 1 below.

[0229] Table 1 Composition of Natural Gas and MDEA

[0230]

[0231] The calculated results were compared with the experimental values, and the results are as follows. Figure 9 , Figure 10 , Figure 11 , Figure 12 as well as Figure 13 As shown, the natural gas deacidification process obtained by the method provided by the present invention is largely consistent with the actual process.

[0232] In summary, the method provided in this application for specific application examples consists of three parts: a physical solubility model and a chemical reaction equilibrium model; the establishment and solution of an equilibrium constant model; and the establishment and solution of a tower model. The physical solubility model includes the solution of the physical solubility of acidic gases. The chemical reaction equilibrium model includes the solution of the equilibrium constants for each chemical reaction and the establishment and solution of a new equilibrium constant model. The tower model includes the iterative solution process for a multi-equilibrium-stage model. In these three parts, this application first combines the equilibrium constants of chemical reactions, physical solubility, and phase equilibrium: considering physical solubility and combining it with phase equilibrium containing chemical reactions, a new equilibrium constant model is derived.

[0233] Next, this application couples the deacidification reaction process with the tower equilibrium stage model: the phase equilibrium constant in the tower equilibrium stage model is replaced with the new equilibrium constant mentioned above for calculation, thus realizing the coupling between the natural gas deacidification chemical reaction process and the tower model calculation.

[0234] Furthermore, this application also provides an overall solution approach for the deacidification tower model: based on the equilibrium stage model and chemical reaction, the program is divided into three iterative solutions, where the first iterative solution solves the chemical equilibrium constant, the second iterative solution solves the phase equilibrium constant, and the third iterative solution solves the tower model. The link between the deacidification reaction and the tower model is the new equilibrium constant established in this invention.

[0235] Finally, this application also calculates the thermodynamic equilibrium when ions and molecules coexist: 1) When ions and molecules coexist in the system, only the thermodynamic equilibrium calculation of molecules is considered, and for the calculation of ions, only the chemical reaction equilibrium constant is considered. 2) For the calculation of the gas-liquid phase equilibrium constant of the solution, only substances present in both the gas phase are included, and the calculation of the chemical reaction equilibrium constant includes substances in the liquid phase.

[0236] This application has the following beneficial effects:

[0237] (1) It improves the generalization ability of the original thermodynamic calculation model.

[0238] A molecular-level thermodynamic model is proposed, which combines Henry's law, chemical reaction equilibrium, and an improved equilibrium constant expression based on phase equilibrium calculations. This model can accurately predict the load of each component when multiple acidic gases coexist, and has been successfully applied to the MDEA-H2O-CO2-H2S-CH4 pentagonal system.

[0239] (2) Reduce computational complexity.

[0240] The method provided in this application not only has a wider computational range, but also a more efficient and concise process. The combination of solubility model, phase equilibrium constant and chemical equilibrium constant is equivalent to transforming the complex chemical absorption process into a relatively simple physical absorption process. At the same time, it also considers the reaction selectivity when multiple acidic gases are present. Compared with complex reaction kinetic simulation, this method can obtain the deacidification simulation results of multi-component systems more quickly and efficiently.

[0241] (3) A coupled model of equilibrium stage model, thermodynamic model and solubility model was constructed.

[0242] A new equilibrium constant is proposed based on the gas-liquid phase equilibrium constant, solubility, and chemical reaction equilibrium constant. Based on this constant and combined with the equilibrium stage model, a complete natural gas deacidification tower model is constructed. This model can be used to calculate not only the physical absorption process but also the chemical absorption process, as well as the changes in substances within the tower model. Solving the natural gas deacidification reaction and the tower model achieves a complete coupling, forming a relatively comprehensive deacidification tower model.

[0243] Based on the same inventive concept, this application also provides a characterization device for a natural gas deacidification process based on a deacidification tower, which can be used to implement the method described in the above embodiments, as shown in the following embodiments. Since the principle of the natural gas deacidification process characterization device based on a deacidification tower is similar to that of the natural gas deacidification process characterization method based on a deacidification tower, the implementation of the natural gas deacidification process characterization device based on a deacidification tower can refer to the implementation of the natural gas deacidification process characterization method based on a deacidification tower, and repeated details will not be elaborated further. As used below, the terms "unit" or "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the system described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0244] The embodiments of this application provide a specific implementation of a natural gas deacidification process characterization device based on a deacidification tower, capable of implementing a method for characterizing the natural gas deacidification process based on a deacidification tower. See [link to relevant documentation]. Figure 14 A characterization device for the natural gas deacidification process based on a deacidification tower specifically includes the following components:

[0245] The first coupling model generation module 10 is used to couple the pre-generated solubility model of the natural gas deacidification process with the chemical reaction equilibrium model to generate the first coupling model.

[0246] The second coupling model generation module 20 is used to couple the chemical reaction equilibrium model with the pre-generated phase equilibrium model of the natural gas deacidification process to generate a second coupling model.

[0247] The equilibrium constant model generation module 30 is used to generate an equilibrium constant model for the natural gas deacidification process based on the first coupling model and the second coupling model.

[0248] The deacidification process characterization module 40 is used to characterize the natural gas deacidification process based on the equilibrium constant model and the pre-generated deacidification tower model.

[0249] In some embodiments of the present invention, see Figure 15 The deacidification process characterization module 40 includes:

[0250] The third coupling model generation unit 40a is used to couple the equilibrium constant model with the deacidification tower model to generate a third coupling model.

[0251] The third coupling model solving unit 40b is used to solve the third coupling model to characterize the natural gas deacidification process.

[0252] In some embodiments of the present invention, the third coupling model solving unit 40b includes:

[0253] A three-layer iterative solution unit is used to solve the third coupled model according to a three-layer iterative solution method; wherein:

[0254] The first layer is used to solve the chemical reaction equilibrium model. The iterative variables in the first layer solution process are the degree of reaction of the chemical reaction equilibrium model and the mole fraction of the feed components.

[0255] The second layer is used to solve the phase equilibrium model. The iterative variables in the solution process of the second layer are the fugacity coefficient of the gas phase and the activity coefficient of the liquid phase.

[0256] The third layer is used to solve the deacidification tower model. The iterative variables in the third layer solution process are the temperature, flow rate, and mole fraction of the components in each tray of the deacidification tower.

[0257] In some embodiments of the present invention, see Figure 16 A characterization device for natural gas deacidification process based on a deacidification tower, further comprising:

[0258] A solubility model generation module 50 is used to generate the solubility model; the solubility model generation module 50 includes:

[0259] A solubility model generation unit is used to generate the solubility model based on the pressure, Henry's law coefficient, and mole fraction of the substances during the natural gas deacidification process.

[0260] A chemical reaction equilibrium model generation module 60, used to generate the chemical reaction equilibrium model, the chemical reaction equilibrium model generation module 60 comprising:

[0261] A chemical reaction equilibrium model generation unit is used to generate the chemical reaction equilibrium model based on the chemical reaction equations and hydrolysis reaction equations of the substances in the natural gas deacidification process; in the chemical reaction equilibrium model, the forward reaction rate and the reverse reaction rate of the substances are equal.

[0262] In some embodiments of the present invention, see Figure 17 A characterization device for natural gas deacidification process based on a deacidification tower, further comprising:

[0263] Phase equilibrium model generation module 70, used to generate the phase equilibrium model, the phase equilibrium model generation module includes:

[0264] The phase equilibrium model generation unit is used to generate the phase equilibrium model based on the system pressure during the natural gas deacidification process, the mole fraction of the component in the gas phase, the mole fraction of the component in the liquid phase, the fugacity coefficient, the activity coefficient, the Henry coefficient, the partial molar volume of the component in water under infinite dilution, the saturated vapor pressure of pure water at the reaction temperature, and the molar volume.

[0265] In some embodiments of the present invention, see Figure 18 A characterization device for natural gas deacidification process based on a deacidification tower, further comprising:

[0266] The deacidification tower model generation module 80 is used to generate the deacidification tower model based on the mass conservation equation, energy conservation equation, normalization equation and phase equilibrium equation of each stage of the deacidification tower.

[0267] The embodiments of this application also provide a specific implementation of an electronic device capable of implementing all steps in the characterization method for the natural gas deacidification process based on a deacidification tower in the above embodiments. See [link to relevant documentation]. Figure 19 The electronic devices specifically include the following:

[0268] Processor 1201, memory 1202, communications interface 1203, and bus 1204;

[0269] The processor 1201, memory 1202, and communication interface 1203 communicate with each other via bus 1204; the communication interface 1203 is used to realize information transmission between server-side devices, power measurement devices, and user-side devices and other related devices.

[0270] The processor 1201 is used to call the computer program in the memory 1202. When the processor executes the computer program, it implements all the steps in the natural gas deacidification process characterization method based on the deacidification tower in the above embodiments. For example, when the processor executes the computer program, it implements the following steps:

[0271] Step 100: Couple the solubility model of the pre-generated natural gas deacidification process with the chemical reaction equilibrium model to generate the first coupled model;

[0272] Step 200: Couple the chemical reaction equilibrium model with the pre-generated phase equilibrium model of the natural gas deacidification process to generate a second coupled model;

[0273] Step 300: Generate an equilibrium constant model for the natural gas deacidification process based on the first coupling model and the second coupling model;

[0274] Step 400: Characterize the natural gas deacidification process based on the equilibrium constant model and the pre-generated deacidification tower model.

[0275] Embodiments of this application also provide a computer-readable storage medium capable of implementing all steps of the natural gas deacidification process characterization method based on a deacidification tower in the above embodiments. The computer-readable storage medium stores a computer program that, when executed by a processor, implements all steps of the natural gas deacidification process characterization method based on a deacidification tower in the above embodiments. For example, when the processor executes the computer program, it implements the following steps:

[0276] Step 100: Couple the solubility model of the pre-generated natural gas deacidification process with the chemical reaction equilibrium model to generate the first coupled model;

[0277] Step 200: Couple the chemical reaction equilibrium model with the pre-generated phase equilibrium model of the natural gas deacidification process to generate a second coupled model;

[0278] Step 300: Generate an equilibrium constant model for the natural gas deacidification process based on the first coupling model and the second coupling model;

[0279] Step 400: Characterize the natural gas deacidification process based on the equilibrium constant model and the pre-generated deacidification tower model.

[0280] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. In particular, hardware + program embodiments are relatively simple in description because they are fundamentally similar to method embodiments; relevant parts can be referred to the descriptions in the method embodiments.

[0281] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0282] While this application provides method operation steps as shown in the embodiments or flowcharts, more or fewer operation steps may be included based on conventional or non-inventive labor. The order of steps listed in the embodiments is merely one possible execution order among many and does not represent the only execution order. In actual device or client product execution, the method can be executed sequentially as shown in the embodiments or drawings, or in parallel (e.g., in a parallel processor or multi-threaded processing environment).

[0283] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0284] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0285] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0286] This application uses specific embodiments to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for characterizing the natural gas deacidification process based on a deacidification tower, characterized in that, include: The solubility model of the pre-generated natural gas deacidification process is coupled with the chemical reaction equilibrium model to generate the first coupled model; The chemical reaction equilibrium model is coupled with the pre-generated phase equilibrium model of the natural gas deacidification process to generate a second coupled model; An equilibrium constant model for the natural gas deacidification process is generated based on the first coupling model and the second coupling model. The natural gas deacidification process is characterized based on the equilibrium constant model and the pre-generated deacidification tower model.

2. The method for characterizing the natural gas deacidification process according to claim 1, characterized in that, The natural gas deacidification process is characterized based on the equilibrium constant model and the pre-generated deacidification tower model, including: The equilibrium constant model is coupled with the deacidification tower model to generate a third coupled model; Solve the third coupling model to characterize the natural gas deacidification process.

3. The method for characterizing the natural gas deacidification process according to claim 2, characterized in that, Solving the third coupling model includes: The third coupling model is solved using a three-layer iterative solution method; wherein: The first layer is used to solve the chemical reaction equilibrium model. The iterative variables in the first layer solution process are the degree of reaction of the chemical reaction equilibrium model and the mole fraction of the feed components. The second layer is used to solve the phase equilibrium model. The iterative variables in the second layer solution process are the fugacity coefficient of the gas phase and the activity coefficient of the liquid phase. The third layer is used to solve the deacidification tower model. The iterative variables in the third layer solution process are the temperature, flow rate, and mole fraction of the components in each tray of the deacidification tower.

4. The method for characterizing the natural gas deacidification process according to claim 1, characterized in that, The steps for generating the solubility model include: The solubility model is generated based on the pressure, Henry's law, and mole fraction of the substances during the natural gas deacidification process. The steps for generating the chemical reaction equilibrium model include: The chemical reaction equilibrium model is generated based on the chemical reaction equations and hydrolysis reaction equations of the substances in the natural gas deacidification process; in the chemical reaction equilibrium model, the forward reaction rate and the reverse reaction rate of the substances are equal.

5. The method for characterizing the natural gas deacidification process according to claim 1, characterized in that, The steps for generating the phase equilibrium model include: The phase equilibrium model is generated based on the system pressure during the natural gas deacidification process, the mole fraction of the component in the gas phase, the mole fraction of the component in the liquid phase, the fugacity coefficient, the activity coefficient, the Henry coefficient, the partial molar volume of the component in water under infinite dilution, the saturated vapor pressure of pure water at the reaction temperature, and the molar volume.

6. The method for characterizing the natural gas deacidification process according to any one of claims 1 to 5, characterized in that, The steps for generating the deacidification tower model include: The deacidification tower model is generated based on the mass conservation equation, energy conservation equation, normalization equation, and phase equilibrium equation for each stage of the deacidification tower.

7. A characterization device for natural gas deacidification process based on a deacidification tower, characterized in that, include: The first coupling model generation module is used to couple the pre-generated solubility model of the natural gas deacidification process with the chemical reaction equilibrium model to generate the first coupling model; The second coupling model generation module is used to couple the chemical reaction equilibrium model with the pre-generated phase equilibrium model of the natural gas deacidification process to generate the second coupling model. The equilibrium constant model generation module is used to generate an equilibrium constant model for the natural gas deacidification process based on the first coupling model and the second coupling model. The deacidification process characterization module is used to characterize the natural gas deacidification process based on the equilibrium constant model and the pre-generated deacidification tower model.

8. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the natural gas deacidification process characterization method based on the deacidification tower as described in any one of claims 1 to 6.

9. An electronic 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, it implements the steps of the natural gas deacidification process characterization method based on a deacidification tower as described in any one of claims 1 to 6.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the method for characterizing the natural gas deacidification process based on a deacidification tower as described in any one of claims 1 to 6.

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