An optimization method and apparatus for a steady-state model of a catalytic cracking regenerator

Abstract

An optimization method and apparatus for a steady-state model of a catalytic cracking regenerator are disclosed, relating to the field of optimizing regenerator operating conditions in catalytic cracking. This optimization method utilizes the molar ratio of hydrogen to carbon in the recycled catalyst to that in the regenerated catalyst, the coking rate, and the fourth-order Runge-Kutta method to optimize the regenerator steady-state model, thereby preventing situations where the oxygen content in the regenerated flue gas and the carbon content of the regenerated catalyst are negative. The catalytic cracking regenerator steady-state model optimization method proposed in this invention can accurately predict the composition of the regenerated flue gas and the carbon content of the regenerated catalyst, which is of great significance for guiding the optimized operation of catalytic cracking regenerator units.

Description

Technical Field

[0001] This invention relates to the field of optimizing the operating conditions of a catalytic cracking regenerator, specifically a method and apparatus for optimizing a steady-state model of a catalytic cracking regenerator. Background Technology

[0002] In industrial catalytic cracking units, the regenerator coking rate is often a key factor determining the unit's processing capacity, especially after the advent of molecular sieve catalysts. To fully utilize their advantages, it is necessary to enhance coking in the regenerator and reduce the carbon content of the regenerator. Enhancing regenerator coking by optimizing operating conditions requires establishing a catalytic cracking regeneration system model. Optimizing regenerator operating conditions often places high demands on the accuracy of the regeneration system model. The higher the prediction accuracy of the catalytic cracking regeneration system model, the more reliable the prediction results.

[0003] Currently, the problems that the regeneration system model may encounter include: (1) under the process conditions of oxygen-deficient regeneration, the oxygen content in the flue gas may be predicted to be negative; (2) the regeneration system model often calculates the combustion reaction of carbon atoms and hydrogen atoms separately. Therefore, under the process conditions of oxygen-enriched regeneration, the carbon atom content or hydrogen atom content on the regenerated catalyst may be predicted to be negative, and the carbon content of the regenerated catalyst may be negative.

[0004] The composition of regenerated flue gas and the carbon determination of the regenerated catalyst are closely related to the temperature and activity of the regenerated catalyst. The temperature of the regenerated catalyst directly affects the reactant-to-oil ratio in catalytic cracking, while the reactant-to-oil ratio and the activity of the regenerated catalyst are key factors influencing the product distribution of catalytic cracking. Therefore, accurately predicting the composition of regenerated flue gas and the carbon determination of the regenerated catalyst are crucial functions of the regeneration system model. Summary of the Invention

[0005] The purpose of this invention is to provide a method and apparatus for optimizing a steady-state model of a catalytic cracking regenerator, which can optimize the model of the catalytic cracking regeneration system, thereby improving its prediction accuracy and accurately predicting the flue gas composition and carbon determination of the regenerated catalyst.

[0006] The technical solution adopted by the present invention to achieve the above-mentioned technical objectives is as follows: an optimization method for the steady-state model of a catalytic cracking regenerator, which optimizes the steady-state model of the regenerator by using the molar ratio of the carbon content of the catalyst to that of the catalyst to that of the regenerated catalyst, the coking rate, and the fourth-order Runge-Kutta method, so as to eliminate the situation where the oxygen content in the regenerated flue gas and the carbon content of the regenerated catalyst are negative.

[0007] As an improved method for optimizing the steady-state model of the catalytic cracking regenerator, the method for optimizing the steady-state model of the regenerator by the molar ratio of the carbon content of the recycled catalyst to the hydrogen-carbon content of the regenerated catalyst is as follows:

[0008] A1) Using the known initial conditions, the flue gas composition, the molar amount of carbon atoms and the molar amount of hydrogen atoms in the regenerator steady-state model are calculated.

[0009] The known initial conditions include the main air flow rate at the regenerator inlet, the regenerator temperature, and the carbon content of the catalyst to be generated.

[0010] A2) When the molar amount n of carbon atoms in the regenerated catalyst calculated in step A1) C When it is less than 0, set w in the regenerator steady-state model. ck,D =exp(n C )·w ck,D The composition of the flue gas, the molar amount of carbon atoms in the regeneration catalyst, and the molar amount of hydrogen atoms were recalculated using the regeneration system model.

[0011] A3) When the molar amount n of hydrogen atoms in the regenerated catalyst calculated in step A1) H When less than 0, set q = exp(n) in the regenerator steady-state model. H )·q, and recalculate the flue gas composition, the molar amount of carbon atoms and the molar amount of hydrogen atoms in the regeneration catalyst through the regeneration system model.

[0012] As an improvement to the above-mentioned steady-state model optimization method for catalytic cracking regenerator, the method for optimizing the regenerator steady-state model by the coke burning rate is as follows:

[0013] B1) Calculated based on the regenerator steady-state model and And set the char rate correction function.

[0014] In the formula, The molar flow rate of oxygen is expressed in kmol / s. This represents the molar flow rate of nitrogen gas, expressed in kmol / s.

[0015] B2) Multiply the coking rate correction function θ from step B1) by the reaction rate constant k in the regenerator steady-state model, and replace the reaction rate constant k in the regenerator steady-state model with the product of the two to complete the optimization of the regenerator steady-state model.

[0016] As an improvement to the above-mentioned steady-state model optimization method for catalytic cracking regenerators, the fourth-order Runge-Kutta method is used to optimize the steady-state model of the regenerator as follows:

[0017] In the regeneration system model In the middle, the initial value is known. Calculate the value after the next time interval h.

[0018] Where, k1=f(yn (38)

[0019]

[0020]

[0021] k4=f(y n +hk3)(41)

[0022] To avoid the case where the oxygen content is negative, when calculating (38), when At that time, set When calculating (39), when At that time, set When calculating (40), when hk3(4)+y n,4 When <0, set k3 = k3·exp(hk3(4)+y n,4 ).

[0023] As an improvement to the above-mentioned steady-state model optimization method for catalytic cracking regenerator, the method for establishing the steady-state model of the catalytic cracking regenerator is as follows:

[0024] S1. Establish a kinetic model of the coking reaction.

[0025] The coke adhering to the surface of the deactivated catalyst is set as a mixture of carbon atoms and hydrogen atoms. During the combustion reaction, carbon atoms are oxidized to produce carbon monoxide and carbon dioxide, and hydrogen atoms are oxidized to produce water. The carbon monoxide produced by the carbon atom reaction will continue to be oxidized to produce carbon dioxide. Based on these four reactions, kinetic models of coke combustion reaction are established respectively.

[0026] S2. Establish a steady-state model for the regenerator.

[0027] Based on the coking reaction kinetic model established in step S1 and the process flow of the catalytic cracking regeneration system, a steady-state model of the regenerator is established.

[0028] As an improved version of the above-mentioned steady-state model optimization method for catalytic cracking regenerator, the reaction equation for the oxidation of carbon atoms to CO and CO2 and the oxidation of hydrogen atoms to H2O during the combustion reaction of S1 is as follows:

[0029]

[0030]

[0031]

[0032] In the formula, r1, r2, and r3 represent the reaction rates of carbon atom oxidation to CO, CO2, and H atom oxidation to H2O, respectively, in kmol coke / (m3 catalyst (s);

[0033] All of the above reactions occur in the dense phase region, and the calculation formulas are as follows:

[0034]

[0035]

[0036]

[0037] In the formula, k is the reaction rate constant, in m³ / s. 3 / (kmol·s); σ represents the molar ratio of CO2 to CO produced, in kmol / kmol; ρ c This indicates the density of catalyst particles in the dense phase region, expressed in kg·m³. -3 ;w ck This indicates the coke content on the catalyst, expressed in kg coke / kg catalyst; MW C Molar molecular mass of carbon atom, expressed in kg / kmol; MW H The molar mass of a hydrogen atom is expressed in kg / kmol; q is the hydrogen-to-carbon molar ratio in coke; c i,j This represents the molar concentration of gaseous component i within region j, in kmol / m³. 3 Region j is either a dense phase region D or a dilute phase bed F, and the gas component i is CO, CO2, H2O, O2 or N2;

[0038] ε c,D The volume fraction of the catalyst in the dense phase region is expressed by the following formula:

[0039]

[0040] In the formula, v g,D This represents the volumetric flow rate of gas in the dense phase region, expressed in meters per second (m³). 3 ·s -1 It is related to the main airflow entering the regenerator; Ω RG This represents the cross-sectional area of ​​the dense phase region of the regenerator;

[0041] The reaction rate constant k is calculated according to the Arrhenius equation using the following formula:

[0042]

[0043] In the formula, R represents the ideal gas constant, 8.314 kJ / (kmol·K); k 10 and E i T represents the pre-exponential factor and activation energy of the reaction, respectively; * Indicates the reference regeneration temperature;

[0044] In equations (4) and (5), the value of σ is determined by the temperature T in the dense phase region of the regenerator:

[0045]

[0046] As another improvement to the above-mentioned steady-state model optimization method for catalytic cracking regenerator, during the combustion reaction of S1, the CO generated by the carbon atom reaction will continue to be oxidized to CO2. This reaction can occur in both the dense phase region and the dilute phase region.

[0047] When the reaction occurs in the dense phase region, the reaction equation and the formula for calculating the reaction rate are as follows:

[0048]

[0049]

[0050] molar concentration c of gas in the dense phase region i,D

[0051]

[0052] In the formula, n i,D This represents the molar flow rate of each gas component in the dense phase region, in kmol·s. -1 ;

[0053] Since no charring reaction occurs in the dilute phase region, only the oxidation of CO takes place. The CO oxidation rate in the dilute phase region is as follows:

[0054]

[0055] c i,F This represents the molar concentration of each gaseous component in the dilute phase region, in kmol / m³. 3 The calculation formula is as follows:

[0056]

[0057] In the formula, n i,F This represents the molar flow rate of each gas component, in kmol·s. -1 .

[0058] As an improvement to the above-mentioned steady-state model optimization method for catalytic cracking regenerator, the method for establishing the steady-state model of the regenerator in S2 is as follows:

[0059] Material balance was performed on the gas in the dense phase region, assuming a constant layer height, to obtain the equations for the rate of change of the molar flow rate of each gas component along the axial direction, as shown below:

[0060]

[0061]

[0062]

[0063]

[0064]

[0065] In the formula, m cat Indicates the amount of regenerator in the dense phase region; Z D Indicates the height of the dense phase layer, in meters (m) and ohms (Ω). RG This represents the average cross-sectional area of ​​the regenerator, in meters (m²). 2 ;

[0066] The initial values ​​of the molar flow rates of each component are calculated as follows:

[0067] n CO,D =0 (19)

[0068]

[0069]

[0070]

[0071]

[0072] In the formula, F air Air mass flow rate, unit: kg / h; MW air This indicates the molecular mass of air, expressed in kg / kmol.

[0073] For the gas in the dilute phase region, which all originate from the dense phase region and includes CO, CO2, and H2O generated by the coking reaction, the molar flow rates of each component are calculated as follows:

[0074]

[0075]

[0076]

[0077]

[0078]

[0079] In the formula, Z F Z represents the height of the rarefaction region, in meters (m). reg This indicates the height of the regenerator, in meters (m).

[0080] Based on the continuity of gas flow, the gas molar flow rate at the inlet of the dilute phase region is equal to the gas molar flow rate at the outlet of the dense phase region, and the calculation formula is as follows:

[0081]

[0082]

[0083]

[0084]

[0085]

[0086] In the above formula, n (0) This represents the molar flow rate of each gas component at the inlet of the dilute phase region, in kmol·s. -1 , This represents the molar flow rate of each gas component at the outlet of the dense phase region, in kmol·s. -1 .

[0087] As an improvement to the above-mentioned steady-state model optimization method for catalytic cracking regenerator, in the steady-state model of the regenerator established in S2, the proportions of each gas component in the flue gas are calculated by the following formula:

[0088]

[0089] In the formula, This represents the molar flow rate of each gas component in the regenerator flue gas, in kmol·s. -1 ;

[0090] The formula for calculating the coke content of the regenerated catalyst is as follows:

[0091]

[0092] The molar amount of carbon atoms n in the regenerated catalyst coke C The calculation formula is as follows:

[0093]

[0094] The molar amount of hydrogen atoms n in the regenerated catalyst coke H The calculation formula is as follows:

[0095]

[0096] A model building apparatus for implementing the above optimization method includes a model building module and a model optimization module, wherein the model building module is used to build a coking reaction kinetic model and a regenerator steady-state model, and the model optimization module is used to optimize the built regenerator steady-state model.

[0097] An electronic device includes a processor and a memory, the memory storing computer-readable instructions that, when executed by the processor, enable the execution of the above-described optimization method.

[0098] A readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the steps in the above-described optimization method.

[0099] Compared with the prior art, the present invention has the following beneficial effects:

[0100] The steady-state model optimization method for catalytic cracking regenerator proposed in this invention can accurately predict the composition of regenerated flue gas and the carbon determination of regenerated catalyst, which is of great significance for guiding the optimized operation of catalytic cracking regeneration unit. Attached Figure Description

[0101] Figure 1 The effect of main air volume on the composition of regenerated flue gas;

[0102] Figure 2 The effect of main air volume on carbon determination of regenerated catalyst;

[0103] Figure 3 The effect of main air volume on the composition of regenerated flue gas;

[0104] Figure 4 The effect of main air volume on carbon determination of regenerated catalyst;

[0105] Figure 5 The effect of main air volume on the composition of regenerated flue gas;

[0106] Figure 6 The effect of main air volume on carbon determination of regenerated catalyst. Detailed Implementation

[0107] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. Any parts not explicitly described in the following embodiments should be understood as prior art known or should be known by those skilled in the art.

[0108] Example 1

[0109] An optimization method for a steady-state model of a catalytic cracking regenerator includes the following steps:

[0110] S1. Establish a kinetic model of the coking reaction.

[0111] The coke adhering to the surface of the deactivated catalyst is set as a mixture of carbon atoms and hydrogen atoms. During the combustion reaction, carbon atoms are oxidized to produce carbon monoxide and carbon dioxide, and hydrogen atoms are oxidized to produce water. The carbon monoxide produced by the carbon atom reaction will continue to be oxidized to produce carbon dioxide. Based on these four reactions, kinetic models of coke combustion reaction are established respectively.

[0112] The specific operation is as follows:

[0113] The coke adhering to the surface of the deactivated catalyst is a mixture, mainly containing carbon atoms (C) and hydrogen atoms (H). During the combustion reaction, carbon atoms are oxidized to produce CO and CO2, and hydrogen atoms are oxidized to produce H2O. When describing the kinetics of the coke reaction, nitrogen (N) and sulfur (S) atoms in the coke are ignored. The reaction equation is as follows:

[0114]

[0115]

[0116]

[0117] In the formula, r1, r2, and r3 represent the reaction rates of carbon atom oxidation to CO, CO2, and H atom oxidation to H2O, respectively, in kmol coke / (m 3 catalyst (s);

[0118] All of the above reactions occur in the dense phase region, and the calculation formulas are as follows:

[0119]

[0120]

[0121]

[0122] In the formula, k is the reaction rate constant, in m³ / s. 3 / (kmol·s); σ represents the molar ratio of CO2 to CO produced, in kmol / kmol; ρ c This indicates the density of catalyst particles in the dense phase region, expressed in kg·m³. -3 ;w ck This indicates the coke content on the catalyst, expressed in kg coke / kg catalyst; MW C Molar molecular mass of carbon atom, expressed in kg / kmol; MW H The molar mass of a hydrogen atom is expressed in kg / kmol; q is the hydrogen-to-carbon molar ratio in coke; c i,j This represents the molar concentration of gaseous component i within region j, in kmol / m³. 3Region j is either a dense phase region D or a dilute phase bed F, and the gas component i is CO, CO2, H2O, O2 or N2;

[0123] ε c,D The volume fraction of the catalyst in the dense phase region is expressed by the following formula:

[0124]

[0125] In the formula, v g,D This represents the volumetric flow rate of gas in the dense phase region, expressed in meters per second (m³). 3 ·s -1 It is related to the main airflow entering the regenerator; Ω RG This represents the cross-sectional area of ​​the dense phase region of the regenerator;

[0126] The reaction rate constant k is calculated according to the Arrhenius equation using the following formula:

[0127]

[0128] In the formula, R represents the ideal gas constant, 8.314 kJ / (kmol·K); k 10 and E i T represents the pre-exponential factor and activation energy of the reaction, respectively; * Indicates the reference regeneration temperature;

[0129] In equations (4) and (5), the value of σ is determined by the temperature T in the dense phase region of the regenerator:

[0130]

[0131] During the combustion reaction, the CO generated by the reaction of carbon atoms will continue to be oxidized to CO2. This reaction can occur in both the dense phase and the dilute phase regions.

[0132] When the reaction occurs in the dense phase region, the reaction equation and the formula for calculating the reaction rate are as follows:

[0133]

[0134]

[0135] molar concentration c of gas in the dense phase region i,D

[0136]

[0137] In the formula, n i,D This represents the molar flow rate of each gas component in the dense phase region, in kmol·s. -1 ;

[0138] Since no charring reaction occurs in the dilute phase region, only the oxidation of CO takes place. The CO oxidation rate in the dilute phase region is as follows:

[0139]

[0140] c i,F This represents the molar concentration of each gaseous component in the dilute phase region, in kmol / m³. 3 The calculation formula is as follows:

[0141]

[0142] In the formula, n i,F This represents the molar flow rate of each gas component, in kmol·s. -1 ;

[0143] S2. Establish a steady-state model for the regenerator.

[0144] Based on the coking reaction kinetic model established in step S1 and the process flow of the catalytic cracking regeneration system, a steady-state model of the regenerator is established.

[0145] The specific operation is as follows:

[0146] Based on the kinetic model of coking reaction and the process flow of the catalytic regeneration system, a steady-state model of the regeneration system is established. The gases in the regenerator include O2, N2, CO, CO2, and H2O. Material balance is performed on the gases in the dense phase region. Assuming the layer height of the dense phase region remains constant, the equations for the rate of change of the molar flow rate of each gas component along the axial direction are obtained, as shown below:

[0147]

[0148]

[0149]

[0150]

[0151]

[0152] In the formula, m cat Indicates the amount of regenerator in the dense phase region; Z D Indicates the height of the dense phase layer, in meters (m) and ohms (Ω). RG This represents the average cross-sectional area of ​​the regenerator, in meters (m²). 2 ;

[0153] The initial values ​​of the molar flow rates of each component are calculated as follows:

[0154] n CO,D =0(19)

[0155]

[0156]

[0157]

[0158]

[0159] In the formula, F air Air mass flow rate, unit: kg / h; MW air This indicates the molecular mass of air, expressed in kg / kmol.

[0160] For the gas in the dilute phase region, which all originate from the dense phase region and includes CO, CO2, and H2O generated by the coking reaction, the molar flow rates of each component are calculated as follows:

[0161]

[0162]

[0163]

[0164]

[0165]

[0166] In the formula, Z F Z represents the height of the rarefaction region, in meters (m). reg This indicates the height of the regenerator, in meters (m).

[0167] Based on the continuity of gas flow, the gas molar flow rate at the inlet of the dilute phase region is equal to the gas molar flow rate at the outlet of the dense phase region, and the calculation formula is as follows:

[0168]

[0169]

[0170]

[0171]

[0172]

[0173] In the above formula, n (0) This represents the molar flow rate of each gas component at the inlet of the dilute phase region, in kmol·s. -1 , This represents the molar flow rate of each gas component at the outlet of the dense phase region, in kmol·s. -1 ;

[0174] The proportions of each gaseous component in the flue gas are calculated using the following formula:

[0175]

[0176] In the formula, This represents the molar flow rate of each gas component in the regenerator flue gas, in kmol·s. -1 ;

[0177] The formula for calculating the coke content of the regenerated catalyst is as follows:

[0178]

[0179] The molar amount of carbon atoms n in the regenerated catalyst coke C The calculation formula is as follows:

[0180]

[0181] The molar amount of hydrogen atoms n in the regenerated catalyst coke H The calculation formula is as follows:

[0182]

[0183] S3. Optimize the steady-state model of the regenerator.

[0184] The steady-state model of the regenerator was optimized using the molar ratio of carbon content in the recycled catalyst to hydrogen content in the regenerated catalyst, the coking rate, and the fourth-order Runge-Kutta method to prevent negative oxygen content in the regenerated flue gas and negative carbon content in the regenerated catalyst. The specific operation is as follows:

[0185] A. The method for optimizing the steady-state model of the regenerator using the molar ratio of carbon in the spent catalyst to hydrogen in the regenerated catalyst is as follows:

[0186] A1) Using the known initial conditions, the flue gas composition, the molar amount of carbon atoms and the molar amount of hydrogen atoms in the regenerator steady-state model are calculated.

[0187] The known initial conditions include the main air flow rate at the regenerator inlet, the regenerator temperature, and the carbon content of the catalyst to be generated.

[0188] A2) When the molar amount n of carbon atoms in the regenerated catalyst calculated in step A1) C When it is less than 0, set w in the regenerator steady-state model. ck,D =exp(n C )·w ck,D The composition of the flue gas, the molar amount of carbon atoms in the regeneration catalyst, and the molar amount of hydrogen atoms were recalculated using the regeneration system model.

[0189] A3) When the molar amount n of hydrogen atoms in the regenerated catalyst calculated in step A1) H When less than 0, set q = exp(n) in the regenerator steady-state model. H )·q, and recalculate the flue gas composition, the molar amount of carbon atoms in the regeneration catalyst, and the molar amount of hydrogen atoms using the regeneration system model;

[0190] B. The method for optimizing the regenerator steady-state model using the coking rate is as follows:

[0191] B1) Calculated based on the regenerator steady-state model and And set the char rate correction function.

[0192] In the formula, The molar flow rate of oxygen is expressed in kmol / s. This represents the molar flow rate of nitrogen gas, expressed in kmol / s.

[0193] B2) Multiply the coking rate correction function θ from step B1) by the reaction rate constant k in the regenerator steady-state model, and replace the reaction rate constant k in the regenerator steady-state model with the product of the two to complete the optimization of the regenerator steady-state model.

[0194] C. The fourth-order Runge-Kutta method is used to optimize the steady-state model of the regenerator.

[0195] In the regeneration system model In the middle, the initial value is known. Calculate the value after the next time interval h.

[0196] Where, k1=f(y n (38)

[0197]

[0198]

[0199] k4=f(y n +hk3)(41)

[0200] To avoid the case where the oxygen content is negative, when calculating (38), when At that time, set When calculating (39), when At that time, set When calculating (40), when hk3(4)+y n,4 When <0, set k3 = k3·exp(hk3(4)+y n,4 ).

[0201] By optimizing the steady-state model of the regenerator using the molar ratio of carbon content in the pre-regenerated catalyst to hydrogen and carbon content in the regenerated catalyst, the coking rate, and the fourth-order Runge-Kutta method, it is possible to ensure that the output flue gas oxygen content and the regenerated catalyst carbon content are not negative under relatively extreme process conditions (oxygen-deficient or oxygen-enriched conditions) without affecting the prediction results of conventional process conditions.

[0202] Example 2

[0203] A model building apparatus for implementing Embodiment 1 includes a model building module and a model optimization module, wherein the model building module is used to build a coking reaction kinetic model and a regenerator steady-state model, and the model optimization module is used to optimize the built regenerator steady-state model.

[0204] Example 3

[0205] An electronic device includes a processor and a memory, the memory storing computer-readable instructions that, when executed by the processor, enable the execution of the optimized method described in Embodiment 1.

[0206] In this embodiment, the electronic device includes a modeling device, a processor, a memory, a storage controller, a peripheral interface, an input / output unit, an audio unit, and a display unit, etc.

[0207] Specifically, the memory, storage controller, processor, peripheral interface, input / output unit, audio unit, and display unit are electrically connected directly or indirectly to each other to achieve data transmission or interaction. The modeling device includes at least one software functional module that can be stored in the memory or embedded in the operating system (OS) of the modeling device in the form of software or firmware. The processor is used to execute the executable module stored in the memory, including the software functional module or computer program.

[0208] The memory can be, but is not limited to, random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable read-only memory (EPROM), electrically erasable read-only memory (EEPROM), etc. The memory stores programs, and after receiving execution instructions, the processor executes the corresponding program. The method executed by the server defined in the flow process of this application can be applied to the processor or implemented by the processor.

[0209] A processor can be an integrated circuit chip with signal processing capabilities. The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), off-the-shelf programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0210] Peripheral interfaces couple various input / output devices to the processor and memory. Peripheral interfaces, processors, and memory controllers can be implemented in a single chip, or they can be implemented separately by independent chips.

[0211] The input / output unit, audio unit, and display unit are all existing technologies. For example, the input / output unit is used to provide users with input data to enable interaction between the user and the server (or local terminal), and can be a mouse, keyboard, etc.; the audio unit provides users with an audio interface, which may include one or more microphones, one or more speakers, and audio circuitry; the display unit provides an interactive interface (e.g., a user operation interface) between the electronic device and the user or is used to display image data for the user's reference.

[0212] Example 4

[0213] A readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the steps of Embodiment 1.

[0214] To verify the effectiveness of the present invention, the following comparative experiments were conducted:

[0215] Experimental Example

[0216] The scheme of Example 1 was used to predict the composition of the regenerator flue gas outlet and the carbon determination of the regenerated catalyst.

[0217] Assuming the regeneration system is in thermal equilibrium, the mass flow rate of the catalyst to be regenerated is 210 kg / s, the fixed carbon content of the catalyst is 1.0 wt%, and the temperature in the dense phase region of the regenerator is 690 °C, predict the impact of the main air volume on the flue gas outlet composition and the fixed carbon content of the regenerated catalyst. The impact of the main air volume on the flue gas outlet composition is shown in [reference needed]. Figure 1 The effect of main air volume on the carbon determination of regenerator is shown in [reference needed]. Figure 2 .

[0218] Comparative Example 1

[0219] Similar to the experimental example, the difference lies in that when optimizing the steady-state model of the regenerator, only the coking rate and the fourth-order Runge-Kutta method were used for optimization, without optimizing the molar ratio of carbon in the spent catalyst to hydrogen in the regenerated catalyst.

[0220] The impact of predicted main air volume on flue gas outlet composition is shown in the following figure. Figure 3 The effect of main air volume on the carbon determination of regenerator is shown in [reference needed]. Figure 4 .contrast Figure 1 and Figure 3 In the experimental case and Comparative Example 1, the predicted flue gas composition was the same under oxygen-deficient conditions; however, the flue gas composition differed slightly under oxygen-rich conditions. (Comparison) Figure 2 and Figure 4 Under oxygen-rich conditions, the experimental example predicted a positive carbon determination value for the regenerator, while Comparative Example 1 predicted a negative carbon determination value for the catalyst.

[0221] Comparative Example 2

[0222] Similar to the experimental example, the difference is that the regenerator steady-state model is not optimized. That is, the molar ratio of carbon in the catalyst to hydrogen in the regenerated catalyst, the coking rate, and the fourth-order Runge-Kutta method are not used to optimize the regenerator steady-state model. Instead, the regenerator steady-state model established in steps S1 and S2 is used directly for prediction.

[0223] The impact of predicted main air volume on flue gas outlet composition is shown in the following figure. Figure 5 The effect of main air volume on the carbon determination of regenerator is shown in [reference needed]. Figure 6 When the main air volume is less than 9.5m³ 3 / kg coke, the calculated oxygen content in the flue gas is negative. When using formulas (14)-(17) in Example 1, the oxygen content is squared, resulting in a complex number with no practical significance. Therefore Figure 5 , Figure 6 Only when the main air volume is greater than 9.5m 3 The data per kg of coke, respectively, are compared with... Figure 3 , Figure 4 same.

[0224] Comparative experiments, Comparative Example 1, and Comparative Example 2 show that the optimization method of this invention can ensure that the oxygen content in the flue gas and the carbon content of the regenerator are not negative under relatively extreme process conditions (oxygen-deficient or oxygen-enriched conditions), which has guiding significance for the design and optimized operation of the regenerator.

[0225] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and various changes and modifications can be made to these embodiments without departing from the principles and essence of the invention. The scope of protection of the present invention is defined only by the appended claims.

Claims

1. An optimization method for a steady-state model of a catalytic cracking regenerator, characterized in that: The steady-state model of the regenerator was optimized using the molar ratio of carbon content of the spent catalyst to hydrogen and carbon content of the regenerated catalyst, the coking rate, and the fourth-order Runge-Kutta method to prevent the oxygen content in the regenerated flue gas and the carbon content of the regenerated catalyst from being negative. The method for optimizing the steady-state model of the regenerator using the molar ratio of carbon in the spent catalyst to hydrogen in the regenerated catalyst is as follows: A1) Using the known initial conditions, the flue gas composition, the molar amount of carbon atoms and the molar amount of hydrogen atoms in the regenerator steady-state model were calculated. The known initial conditions include the main air flow rate at the regenerator inlet, the regenerator temperature, and the carbon content of the catalyst to be generated. A2) When the molar amount of carbon atoms in the regenerated catalyst calculated in step A1) When less than 0, the steady-state model of the regenerator is set. The composition of the flue gas, the molar amount of carbon atoms in the regeneration catalyst, and the molar amount of hydrogen atoms were recalculated using the regeneration system model. A3) When the molar amount of hydrogen atoms in the regenerated catalyst calculated in step A1) When less than 0, the steady-state model of the regenerator is set. The composition of the flue gas, the molar amount of carbon atoms in the regeneration catalyst, and the molar amount of hydrogen atoms were recalculated using the regeneration system model. The method for optimizing the regenerator steady-state model using the charring rate is as follows: B1) Calculated based on the regenerator steady-state model and And set the char rate correction function. ; In the formula, The molar flow rate of oxygen is expressed in kmol / s. This represents the molar flow rate of nitrogen gas, expressed in kmol / s. B2) The char rate correction function in step B1) Multiply by the reaction rate constant k in the regenerator steady-state model, and replace the reaction rate constant k in the regenerator steady-state model with the product of the two to complete the optimization of the regenerator steady-state model; The method for optimizing the regenerator steady-state model using the fourth-order Runge-Kutta method is as follows: In the regeneration system model In the middle, the initial value is known. Calculate the value after the next time interval h. ; in, (38) （39） （40） （41） To avoid the case where the oxygen content is negative, when calculating (38), when At that time, set When calculating (39), when At that time, set When calculating (40), when At that time, set .

2. The optimization method for a steady-state model of a catalytic cracking regenerator according to claim 1, characterized in that, The method for establishing the steady-state model of the catalytic cracking regenerator is as follows: S1. Establish a kinetic model of the coking reaction. The coke adhering to the surface of the deactivated catalyst is set as a mixture of carbon atoms and hydrogen atoms. During the combustion reaction, carbon atoms are oxidized to produce carbon monoxide and carbon dioxide, and hydrogen atoms are oxidized to produce water. The carbon monoxide produced by the carbon atom reaction will continue to be oxidized to produce carbon dioxide. Based on these four reactions, kinetic models of coke combustion reaction are established respectively. S2. Establish a steady-state model for the regenerator. Based on the coking reaction kinetic model established in step S1 and the process flow of the catalytic cracking regeneration system, a steady-state model of the regenerator is established.

3. The optimization method for a steady-state model of a catalytic cracking regenerator according to claim 2, characterized in that, In the combustion reaction of S1, carbon atoms are oxidized to produce CO and CO2, and hydrogen atoms are oxidized to produce H2O. The reaction equation is as follows: （1） （2） （3） In the formula, , , These represent the reaction rates of carbon atom oxidation to CO, CO2, and H atom oxidation to H2O, respectively, in units of... ; All of the above reactions occur in the dense phase region, and the calculation formulas are as follows: （4） （5） （6） In the formula, The reaction rate constant is expressed in units of 1 / 3 and 2 / 3. ; This represents the molar ratio of CO2 to CO produced, in units of... ; This represents the density of catalyst particles in the dense phase region, expressed in units of... ; Indicates the coke content on the catalyst, in units of ; The molar molecular mass of a carbon atom is expressed in units of... ; The molar molecular mass of a hydrogen atom is expressed in units of... ; The hydrogen-to-carbon molar ratio in coke; Indicates in Gas components in the region molar concentration, in units , The region is either the dense phase region D or the dilute phase region F, and the gas components are... It can be CO, CO2, H2O, O2, or N2; The volume fraction of the catalyst in the dense phase region is expressed by the following formula: （7） In the formula, This represents the volumetric flow rate of gas in the dense phase region, expressed in units of... It is related to the main airflow entering the regenerator; This represents the cross-sectional area of ​​the dense phase region of the regenerator; Reaction rate constant According to the Arrhenius equation, it can be calculated using the following formula: （8） In the formula, R represents the ideal gas constant, 8.

314. ; and These represent the pre-exponential factor and activation energy of the reaction, respectively. Indicates the reference regeneration temperature; In equations (4) and (5), The value is determined by the temperature of the dense phase region inside the regenerator. Sure: （9）。 4. The optimization method for a steady-state model of a catalytic cracking regenerator according to claim 3, characterized in that, During the combustion reaction of S1, the CO generated by the reaction of carbon atoms will continue to be oxidized to CO2. This reaction can occur in both the dense phase region and the dilute phase region. When the reaction occurs in the dense phase region, the reaction equation and the formula for calculating the reaction rate are as follows: （10） molar concentration of gas in the dense phase region （11） In the formula, Represents the molar flow rate of each gas component in the dense phase region, in units of... ; Since no charring reaction occurs in the dilute phase region, only the oxidation of CO takes place. The CO oxidation rate in the dilute phase region is as follows: （12） Represents the molar concentration of each gaseous component in the dilute phase region, in units of... The calculation formula is as follows: （13） In the formula, Indicates the molar flow rate of each gas component, in units of... .

5. The optimization method for a steady-state model of a catalytic cracking regenerator according to claim 4, characterized in that, The method for establishing the regenerator steady-state model in S2 is as follows: Material balance was performed on the gas in the dense phase region, assuming a constant layer height, to obtain the equations for the rate of change of the molar flow rate of each gas component along the axial direction, as shown below: （14） （15） （16） （17） （18） In the formula, This indicates the height of the dense phase layer, in meters (m). This represents the average cross-sectional area of ​​the regenerator, in meters (m²). 2 ; The initial values ​​of the molar flow rates of each component are calculated as follows: （19） （20） （21） （22） （23） In the formula, Indicates air mass flow rate, unit ; Indicates the molecular mass of air, unit ; For the gas in the dilute phase region, which all originate from the dense phase region and includes CO, CO2, and H2O generated by the coking reaction, the molar flow rates of each component are calculated as follows: （24） （25） （26） （27） （28） In the formula, This indicates the height of the rarefaction region, in meters (m). Based on the continuity of gas flow, the gas molar flow rate at the inlet of the dilute phase region is equal to the gas molar flow rate at the outlet of the dense phase region, and the calculation formula is as follows: （29） （30） （31） （32） （33） In the above formula, Represents the molar flow rate of each gas component at the inlet of the dilute phase region, in units of... , This represents the molar flow rate of each gas component at the outlet of the dense phase region, in units of... .

6. The optimization method for a steady-state model of a catalytic cracking regenerator according to claim 5, characterized in that, In the regenerator steady-state model established in S2, the proportions of each gas component in the flue gas are calculated by the following formula: （34） In the formula, Indicates the molar flow rate of each gas component in the regenerator flue gas, in units of... ; The formula for calculating the coke content of the regenerated catalyst is as follows: （35） Molar amount of carbon atoms in the regenerated catalyst coke The calculation formula is as follows: （36） Molar amount of hydrogen atoms in the regenerated catalyst coke The calculation formula is as follows: （37）。 7. A model building apparatus for implementing the optimization method according to any one of claims 1-6, characterized in that: It includes a model building module and a model optimization module. The model building module is used to build a coking reaction kinetic model and a regenerator steady-state model, and the model optimization module is used to optimize the built regenerator steady-state model.

8. An electronic device, characterized in that, It includes a processor and a memory, the memory storing computer-readable instructions that, when executed by the processor, enable the execution of the optimized method according to any one of claims 1-6.

9. A readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it performs the steps of the optimization method according to any one of claims 1-6.

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