Simulation method and system for styrene preparation reaction through ethylbenzene dehydrogenation

Abstract

The invention relates to a method for simulating reaction for preparing styrene by ethylbenzene dehydrogenation. The method comprises the following steps: step 1) establishing a reaction kinetic equation of a chemical reaction; step 2) establishing a material balance equation of each reactant and reaction product according to the reaction kinetic equation in the step 1); 3) establishing an energy balance equation according to the material balance equation in the step 2); (4) establishing a momentum balance equation according to the material balance equation in the step (2) and the energy balance equation in the step (3); (5) adopting the reaction kinetic equation, the material balance equation, the energy balance equation and the momentum balance equation; according to the content of each component in the raw material fed into the reactor, the temperature of the raw material, the pressure of the raw material and the structural parameters of the reactor, simulating and calculating to obtain the content of each component in a reaction product output by the reactor, the temperature of the reaction product and the pressure of the reaction product.

Description

Technical Field

[0001] The invention relates to the technical field of chemical engineering, and in particular to a simulation method and system for a reaction of ethylbenzene dehydrogenation to produce styrene. Background Art

[0002] In the chemical industry, ethylbenzene dehydrogenation is a process in which ethylbenzene is used as raw material and, under the action of a catalyst, a dehydrogenation reaction is performed to produce styrene. Styrene is a very important organic chemical raw material, which is widely used in the production of plastics and synthetic rubber, including polystyrene (PS), acrylonitrile-butadiene-styrene terpolymer (ABS), styrene-acrylonitrile copolymer (SAN), ion exchange resin, styrene-based thermoplastic elastomer (SBS) and unsaturated polyester.

[0003] In the early stage of the development of the ethylbenzene dehydrogenation process to produce styrene, zinc and magnesium catalysts were used, but they were soon replaced by iron-potassium catalysts with better performance. In recent years, ethylbenzene dehydrogenation catalysts have been further developed and researched in the direction of reducing the potassium content of the catalyst, reducing the water-to-hydrocarbon ratio of the catalyst and increasing the life of the catalyst. At present, the life of industrial catalysts is generally 2 to 3 years. The main processes for ethylbenzene dehydrogenation to produce styrene include Lummus / UOP technology, Fina / Badger technology, BASF technology and domestic ST technology. The industrial production of styrene in China began in the 1950s, and many sets of equipment were introduced and built one after another. In the 1990s, East China University of Science and Technology developed an axial radial reactor for ethylbenzene negative pressure dehydrogenation. The domestic ST technology developed in cooperation with Sinopec Shanghai Petrochemical Research Institute and Sinopec Shanghai Engineering Company has successfully built many industrial units and achieved good operating results.

[0004] The dehydrogenation reaction of ethylbenzene is a process controlled by chemical reaction and diffusion. The reaction is relatively complex and there are many influencing factors. It is generally believed that the dehydrogenation of adsorbed ethylbenzene with adjacent vacancies to produce adsorbed hydrogen and adsorbed styrene is the controlling step that determines the speed of the reaction. Reaction temperature, pressure, water-hydrocarbon ratio, etc. have a great influence on the reaction yield. The kinetics of ethylbenzene dehydrogenation reaction is an important method to explore the reaction mechanism, and many researchers have studied the kinetics of ethylbenzene dehydrogenation reaction.

[0005] The study of the reaction kinetics of ethylbenzene dehydrogenation to styrene has greatly promoted the progress of the process, but there are still problems such as the model involving reaction components is not detailed enough and the treatment of the reactor model is not perfect. First, the steam conversion reaction of small molecules is rarely considered. Since the tail gas treatment of the ethylbenzene dehydrogenation process needs to go through the absorption and desorption process, the tail gas composition cannot be predicted and calculated without considering the steam conversion reaction of small molecules. In addition, the research on the dehydrogenation reaction of ethylbenzene often ignores the side reactions caused by impurities. Since most of the feed ethylbenzene comes from the catalytic dry gas to ethylbenzene unit, a small amount of isopropylbenzene will be entrained in the ethylbenzene produced by this process. The α-methylstyrene generated by the dehydrogenation of isopropylbenzene is very easy to self-polymerize, thus affecting the normal operation of the reactor. Summary of the invention

[0006] The present invention proposes a ST process ethylbenzene dehydrogenation reaction simulation method and system, which includes 1 main reaction and 8 side reactions, covering the steam conversion reaction of small molecules and the side reaction of generating α-methylstyrene, and can more comprehensively predict the reaction process, facilitate the full process simulation of the styrene device in the later stage, and then optimize the device system, improve the device efficiency and the market competitiveness of styrene products. The present invention is implemented by the following technical solutions:

[0007] A simulation method for the dehydrogenation of ethylbenzene to produce styrene comprises the following steps:

[0008] Step 1) Establish the reaction kinetics equation of the following chemical reaction:

[0009] Reaction 1: Ethylbenzene reacts to produce styrene and hydrogen;

[0010] Reaction 2: Ethylbenzene reacts to produce benzene and ethylene;

[0011] Reaction 3: Ethylbenzene and hydrogen react to form toluene and methane;

[0012] Reaction 4: Styrene and hydrogen react to produce benzene and ethylene;

[0013] Reaction 5: Styrene and hydrogen react to produce toluene and methane;

[0014] Reaction 6: Methane and water react to produce carbon monoxide and hydrogen;

[0015] Reaction 7: Carbon monoxide reacts with water to produce carbon dioxide and hydrogen;

[0016] Reaction 8: Ethylene and water react to produce carbon monoxide and hydrogen;

[0017] Reaction 9: Cumene reacts to produce α-methylstyrene and hydrogen;

[0018] Step 2) establishing a material balance equation for each reactant and reaction product according to the reaction kinetic equation in step 1);

[0019] Step 3) establishing an energy balance equation based on the material balance equation in step 2);

[0020] Step 4) establishing a momentum balance equation based on the material balance equation in step 2 and the energy balance equation in step 3);

[0021] Step five) using the reaction kinetics equation, material balance equation, energy balance equation and momentum balance equation, according to the content of each component in the raw material fed into the reactor, the raw material temperature, the raw material pressure, and the reactor structural parameters, the simulation calculation obtains the content of each component in the reaction product output by the reactor, the reaction product temperature, and the reaction product pressure.

[0022] Optionally, the reaction kinetics equation includes:

[0023]

[0024] K P =C1×exp(C2-C3 / T-C4×log(T))

[0025] Among them, r 1 ~r 9 are the reaction rates of reactions 1 to 9, in kmol / (kg·h); Kp is the equilibrium constant of the main reaction, in kPa; C1 to C4 are correlation constants; k i is the reaction rate constant, unit kmol / (kg·h·kPa m ·K n ), where m is determined by dimensional analysis and is equal to 1-total number of series, and n is only r 7 Use, value is 3; k i0 is the reaction rate pre-exponential factor, with the same unit as k i Same; E a is the activation energy, in J / mol; b j is the adsorption constant, unit kPa -1 ; b j0 is the adsorption pre-exponential factor, unit kPa -1 ;Q j is the adsorption activation energy, in J / mol. ST is the partial pressure of styrene, P EB is the partial pressure of ethylbenzene, P H2O is the water partial pressure, P H2 is the hydrogen partial pressure, P C2H4 is the ethylene partial pressure, P CH4 is the methane partial pressure, P CO is the partial pressure of carbon monoxide, P ISBis the partial pressure of cumene

[0026] Optionally, the material balance equation is:

[0027]

[0028]

[0029] The flow rate change rate of impurity components that do not participate in the reaction, such as p-xylene, p-diethylbenzene and non-aromatics, is 0:

[0030]

[0031] Where F is the molar flow rate of the component, in kmol·h -1 , r 1 ~r 9 is the reaction rate of reactions 1 to 9, in kmol kg -1 ·h -1 , r is the bed radius, unit is m, L is the bed height, unit is m, ρ is the catalyst bulk density, unit is kg·m -3 , F Other Represents impurities. ST is the molar flow rate of styrene, F TL is the molar flow rate of toluene, F EB is the molar flow rate of ethylbenzene, F BZ is the molar flow rate of benzene, F H2O is the water molar flow rate, F H2 is the hydrogen molar flow rate, F C2H4 is the molar flow rate of ethylene, F CH4 is the molar flow rate of methane, F CO is the molar flow rate of carbon monoxide, F CO2 is the molar flow rate of carbon dioxide, F ISB is the molar flow rate of cumene, F AMS is the molar flow rate of α-methylstyrene, F other It is an impurity that does not participate in the reaction.

[0032] Optionally, the energy balance equation is:

[0033]

[0034] Where ΔH j is the enthalpy change of each reaction, j = 1 to 9, unit J·mol -1 ; C pi is the molar heat capacity at constant pressure, i = 1 to 19, unit J·mol -1 ·K -1 .

[0035] Optionally, the momentum balance equation is:

[0036]

[0037] Where ε is the bed porosity, d p is the equivalent diameter of the catalyst particle specific surface area, in m, μ is the dynamic viscosity of the mixed gas, in Pa·s, and u is the gas superficial velocity, in m·s -1 .

[0038] Optionally, the reactor in the step five) includes a first reactor and a second reactor connected in series, and the reaction kinetics equation, material balance equation, energy balance equation and momentum balance equation are used to sequentially calculate the reaction product temperature, reaction product pressure and reaction product composition of the first reactor and the second reactor.

[0039] Optionally, a heat exchanger is provided on the second reactor, and the heat exchange temperature of the heat exchanger is calculated using the following formula:

[0040]

[0041] Where T in,steam is the steam inlet temperature, in K, T out,steam is the steam outlet temperature, unit K, F steam is the steam molar flow rate, unit is kmol·h -1 , C p,steam is the molar heat capacity of steam at constant pressure, in J·mol -1 ·K -1 , T in,Material is the reaction material inlet temperature, unit K, T out,Material is the outlet temperature of the reaction material, unit K, F Material is the molar flow rate of the reaction material, unit is kmol·h -1 , C p,Material is the molar heat capacity of the reaction materials at constant pressure, in J·mol -1 ·K -1 .

[0042] A simulation system for the reaction of ethylbenzene dehydrogenation to produce styrene, comprising:

[0043] Reaction kinetics module, used to calculate the reaction rates of individual reactions in the reactor;

[0044] Reaction material balance module, used to calculate the flow and composition of each reaction raw material and reaction product in the reactor;

[0045] Reaction energy balance module, used to calculate the temperature change and reaction heat in the reactor;

[0046] Reaction momentum balance module to calculate the pressure change in the reactor.

[0047] The reaction of the reactor includes:

[0048] Ethylbenzene reacts to produce styrene and hydrogen;

[0049] Ethylbenzene reacts to produce benzene and ethylene;

[0050] Ethylbenzene reacts with hydrogen to produce toluene and methane;

[0051] Styrene reacts with hydrogen to produce benzene and ethylene;

[0052] Styrene reacts with hydrogen to produce toluene and methane;

[0053] Methane and water react to form carbon monoxide and hydrogen;

[0054] Carbon monoxide reacts with water to form carbon dioxide and hydrogen;

[0055] Ethylene reacts with water to produce carbon monoxide and hydrogen;

[0056] Cumene reacts to produce α-methylstyrene and hydrogen.

[0057] Optionally, the reactor includes a first reactor and a second reactor connected in series.

[0058] Optionally, a heat exchanger is provided on the second reactor, and the system further comprises:

[0059] The heat exchange calculation module is used to calculate the heat exchange temperature and heat exchange load of the heat exchanger.

[0060] Compared with the prior art, the present invention has the following advantages and effects:

[0061] The present invention proposes a method and system for simulating the reaction of ethylbenzene dehydrogenation to produce styrene in an ST process. The method and system are characterized in that a reaction network and a reaction kinetics model including one main reaction and eight side reactions are constructed based on the reaction mechanism of ethylbenzene dehydrogenation to produce styrene. A two-stage series one-dimensional pseudo-homogeneous radial reactor model with intermediate heat exchange is established based on the structural type of the ethylbenzene dehydrogenation reactor in the ST process. A model equation group including reaction material balance, heat balance, reactor pressure drop calculation and intermediate heat exchanger heat exchange calculation is established based on the reaction network and in combination with the reactor model, so that a more comprehensive simulation prediction of the ethylbenzene dehydrogenation reaction process can be performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a structural diagram of a reactor of the present invention. DETAILED DESCRIPTION

[0063] In order to make the purpose and technical solution of the present invention more clear, the present invention is further described in detail. The experimental methods described in the following examples are all conventional methods unless otherwise specified: if no specific techniques or conditions are specified in the examples, they are carried out according to the techniques or conditions described in the literature in the field or according to the product instructions; the reagents and materials, unless otherwise specified, can be obtained from commercial channels.

[0064] Example 1

[0065] The present invention provides a simulation method for the reaction of ethylbenzene dehydrogenation to produce styrene, comprising the following steps:

[0066] Step 1) Establish the reaction kinetics equation of the following chemical reaction:

[0067] Reaction 1: Ethylbenzene reacts to produce styrene and hydrogen;

[0068] Reaction 2: Ethylbenzene reacts to produce benzene and ethylene;

[0069] Reaction 3: Ethylbenzene and hydrogen react to form toluene and methane;

[0070] Reaction 4: Styrene and hydrogen react to produce benzene and ethylene;

[0071] Reaction 5: Styrene and hydrogen react to produce toluene and methane;

[0072] Reaction 6: Methane and water react to produce carbon monoxide and hydrogen;

[0073] Reaction 7: Carbon monoxide reacts with water to produce carbon dioxide and hydrogen;

[0074] Reaction 8: Ethylene and water react to produce carbon monoxide and hydrogen;

[0075] Reaction 9: Cumene reacts to produce α-methylstyrene and hydrogen;

[0076] Step 2) establishing a material balance equation for each reactant and reaction product according to the reaction kinetic equation in step 1);

[0077] Step 3) establishing an energy balance equation based on the material balance equation in step 2);

[0078] Step 4) establishing a momentum balance equation based on the material balance equation in step 2 and the energy balance equation in step 3);

[0079] Step five) using the reaction kinetics equation, material balance equation, energy balance equation and momentum balance equation, according to the content of each component in the raw materials fed into the reactor, the raw material temperature, the raw material pressure, and the reactor structural parameters, the simulation calculation obtains the content of each component in the reaction product output by the reactor, the reaction product temperature, the reaction product pressure and the reaction product composition.

[0080] Reactor Figure 1 The figure shows a two-stage series radial reactor model, which includes a first reactor and a second reactor in series, wherein a heat exchanger is also provided at the inlet of the second reactor.

[0081] Reactions considered include:

[0082]

[0083] EB→BZ+C 2 H 4 (2)

[0084] EB+H 2 →TL+CH 4 (3)

[0085] ST+H 2 →BZ+C 2 H 4 (4)

[0086] ST+2H 2 →TL+CH 4 (5)

[0087] CH 4 +H 2 O→CO+3H 2 (6)

[0088] CO+H 2 O→CO 2 +H 2 (7)

[0089] 0.5C 2 H 4 +H 2 O→CO+2H 2 (8)

[0090] ISB→AMS+H 2 (9)

[0091] Among them, EB is ethylbenzene, ST is styrene, TL is toluene, BZ is benzene, ISB is isopropylbenzene, and AMS is α-methylstyrene.

[0092] The reaction kinetics equation includes:

[0093]

[0094] K P =C1×exp(C2-C3 / T-C4×log(T))(21)

[0095] Where r is the reaction rate (kmol / (kg·h)), Kp is the main reaction equilibrium constant (kPa), C1~C4 are correlation constants, which are obtained from the existing public ethylbenzene dehydrogenation to styrene reaction data according to the reaction conditions such as the catalyst used, and k i is the reaction rate constant (kmol / (kg·h·kPa m ·K n ) where m is determined by dimensional analysis and is equal to 1-total number of series, and n is only r 7 Use, value is 3), k i0 is the reaction rate pre-exponential factor, with the same unit as k i Same, E a is the activation energy (J / mol), b j is the adsorption constant (kPa -1 ), b j0 is the adsorption pre-exponential factor, Q j is the adsorption activation energy (J / mol).

[0096] The ethylbenzene dehydrogenation reactor model is a two-stage series radial reactor model with intermediate heat exchange. The reactor structure is as follows Figure 1 As shown, the catalyst is loaded in the annular area of ​​the reactor. After the ethylbenzene vapor is heated by heat exchange, it is mixed with the superheated water vapor at the inlet of the first dehydrogenation reactor and enters the catalyst bed along the axial radial direction. The dehydrogenation reaction occurs under negative pressure adiabatic conditions. Since the dehydrogenation of ethylbenzene is an endothermic reaction, the outlet temperature of the first dehydrogenation reactor decreases. After the temperature is increased by heat exchange with the superheated water vapor in the intermediate heat exchanger, it enters the catalyst bed of the second dehydrogenation reactor to realize the two-stage negative pressure adiabatic dehydrogenation reaction. The logistics discharged from the outlet of the second dehydrogenation reactor is the final reaction product.

[0097] The mathematical model equation group of the ethylbenzene dehydrogenation reactor includes a material balance equation, a heat balance equation, a momentum balance equation and a heat balance equation for an intermediate heat exchanger.

[0098] The material balance equation is:

[0099]

[0100] Impurity components that do not participate in the reaction, such as p-xylene, p-diethylbenzene and non-aromatics, have a flow rate change rate of 0:

[0101]

[0102] Where F is the molar flow rate (kmol / h), r i is the reaction rate (kmol kg -1 ·h -1), i = 1 ~ 9, r is the bed radius (m), L is the bed height (m), ρ is the catalyst bulk density (kg / m3), Other represents impurities, specifically including: o-xylene, m-xylene, p-xylene, o-diethylbenzene, m-diethylbenzene, p-diethylbenzene and non-aromatics.

[0103] The energy balance equation is:

[0104]

[0105] Where ΔH j is the enthalpy change of each reaction, j = 1 to 9, unit J·mol -1 , C pi is the molar heat capacity at constant pressure, i = 1 to 19, unit J·mol -1 ·K -1 , the energy balance considers 9 reactions and 19 components (including reactants and major impurities, where i from 1 to 19 represents ethylbenzene, styrene, toluene, benzene, water, hydrogen, ethylene, methane, carbon monoxide, carbon dioxide, cumene, α-methylstyrene, o-xylene, m-xylene, p-xylene, o-diethylbenzene, m-diethylbenzene, p-diethylbenzene, and non-aromatics). The heat of each reaction is as follows:

[0106] ΔH 1 =-120697-4.56T / K

[0107] ΔH 2 =-108750+7.95T / K

[0108] ΔH 3 =53145+13.18T / K

[0109] ΔH 4 =11929+12.51T / K

[0110] ΔH 5 =173824+17.74T / K

[0111] ΔH 6 =-206100

[0112] ΔH 7 =41000

[0113] ΔH 8 =-225600

[0114] ΔH 9 =-119554

[0115] The constant pressure heat capacity equations of each component and mixture are as follows:

[0116] C P,i=A i +B i ×T+C i ×T 2 +D i ×T 3

[0117]

[0118] where y i is the mole fraction, A, B, C, and D are correlation constants derived from a public database. The momentum loss is based on the pressure drop formula for fluid flowing in an empty circular tube, specifically:

[0119]

[0120] Where ε is the bed porosity, d p is the equivalent diameter of the catalyst particle specific surface area, in m, μ is the dynamic viscosity of the mixed gas, in Pa·s, and u is the gas superficial velocity, in m·s -1 , the viscosity equations of each component and mixture are as follows:

[0121]

[0122] Among them, μ i is the viscosity of the pure component, in Pa·s, C i is the viscosity correlation constant, which comes from a public database, i = 1~4, μ mix is the viscosity of the mixture, in Pa·s, M i is the relative molecular mass, i = 1 to 19, unit: g·mol -1 .

[0123] The heat balance equation of the intermediate heat exchanger is:

[0124]

[0125] Where T in,steam is the steam inlet temperature, in K, T out,steam is the steam outlet temperature, unit K, F steam is the steam molar flow rate, unit is kmol·h -1 , C p,steam is the molar heat capacity of steam at constant pressure, in J·mol -1 ·K -1 , T in,Material is the reaction material inlet temperature, unit K, T out,Material is the outlet temperature of the reaction material, unit K, F Material is the molar flow rate of the reaction material, unit is kmol·h -1 , C p,Materialis the molar heat capacity of the reaction materials at constant pressure, in J·mol -1 ·K -1 .

[0126] Test example

[0127] The component properties, property correlation constants, adsorption equilibrium constants, and reaction kinetic constants contained in the mathematical equations in the simulation method are all retrieved from publicly published data such as chemical property manuals and databases.

[0128] The feed data of the simulation input are shown in Table 1.

[0129] Table 1 Input feed data

[0130]

[0131]

[0132] The device structure and catalyst data of the simulation input are shown in Table 2.

[0133] Table 2 Input equipment structure and catalyst data

[0134]

[0135] The response operation data of the simulated input are shown in Table 3.

[0136] Table 3 Input reaction operation data

[0137] project unit Numeric Second reactor inlet temperature ℃ 615 Second reactor inlet pressure Kpa 30 Intermediate heat exchanger steam inlet temperature ℃ 814 Steam inlet pressure of intermediate heat exchanger Kpa 250 Steam mass flow rate of intermediate heat exchanger kg / h 13700

[0138] The data in Tables 1 to 3 are input into the mathematical equation group in the simulation method, and the fourth-order Runge-Kutta method is used to solve it. The comparison results of the reaction product composition and the reactor temperature drop and pressure drop with the actual factory values ​​are shown in Table 4.

[0139] Table 4 Comparison between simulation value and factory value

[0140]

[0141]

[0142] As can be seen from Table 4, the simulated compositions of key components such as ethylbenzene, styrene, and hydrogen, as well as the temperature drop and pressure drop results of each reactor are relatively close to the actual factory values. Only the compositions of by-products with relatively small contents such as benzene, toluene, and carbon dioxide have slightly larger deviations.

[0143] The present invention also proposes a simulation system for the dehydrogenation of ethylbenzene to produce styrene reaction based on the above method, comprising: a reaction kinetics module for calculating the reaction rate of each reaction in the reactor;

[0144] Reaction material balance module, used to calculate the flow and composition of each reaction raw material and reaction product in the reactor;

[0145] Reaction energy balance module, used to calculate the temperature change and reaction heat in the reactor;

[0146] Reaction momentum balance module, used to calculate the pressure change in the reactor;

[0147] The reaction of the reactor includes:

[0148] Reaction 1: Ethylbenzene reacts to produce styrene and hydrogen;

[0149] Reaction 2: Ethylbenzene reacts to produce benzene and ethylene;

[0150] Reaction 3: Ethylbenzene and hydrogen react to form toluene and methane;

[0151] Reaction 4: Styrene and hydrogen react to produce benzene and ethylene;

[0152] Reaction 5: Styrene and hydrogen react to produce toluene and methane;

[0153] Reaction 6: Methane and water react to produce carbon monoxide and hydrogen;

[0154] Reaction 7: Carbon monoxide reacts with water to produce carbon dioxide and hydrogen;

[0155] Reaction 8: Ethylene and water react to produce carbon monoxide and hydrogen;

[0156] Reaction 9: Isopropylbenzene reacts to produce α-methylstyrene and hydrogen.

[0157] The heat exchange calculation module, the reactor includes a first reactor and a second reactor connected in series, the second reactor is provided with a heat exchanger, and the heat exchange calculation module is used to calculate the heat exchange temperature and heat exchange load of the heat exchanger.

[0158] In addition, it should be noted that the above are only preferred embodiments of the present invention and are not limited to the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A simulation method for the dehydrogenation of ethylbenzene to produce styrene, characterized in that: The following steps are involved: Step 1) Establish the reaction kinetics equation of the following chemical reaction: Reaction 1: Ethylbenzene reacts to produce styrene and hydrogen; Reaction 2: Ethylbenzene reacts to produce benzene and ethylene; Reaction 3: Ethylbenzene and hydrogen react to form toluene and methane; Reaction 4: Styrene and hydrogen react to produce benzene and ethylene; Reaction 5: Styrene and hydrogen react to produce toluene and methane; Reaction 6: Methane and water react to produce carbon monoxide and hydrogen; Reaction 7: Carbon monoxide reacts with water to produce carbon dioxide and hydrogen; Reaction 8: Ethylene and water react to produce carbon monoxide and hydrogen; Reaction 9: Cumene reacts to produce α-methylstyrene and hydrogen; Step 2) establishing a material balance equation for each reactant and reaction product according to the reaction kinetics equation in step 1); Step 3) establishing an energy balance equation according to the material balance equation in step 2); Step 4) establishing a momentum balance equation according to the material balance equation in step 2 and the energy balance equation in step 3); Step 5) using the reaction kinetics equation, material balance equation, energy balance equation and momentum balance equation, according to the content of each component in the raw materials fed into the reactor, the raw material temperature, the raw material pressure, and the reactor structural parameters, simulate and calculate the content of each component in the reaction product output by the reactor, the reaction product temperature, and the reaction product pressure.

2. The simulation method for the reaction of ethylbenzene dehydrogenation to styrene according to claim 1, characterized in that: The reaction kinetics equation includes: K P =C1×exp(C2-C3 / T-C4×log(T)) Among them, r1~r9 are the reaction rates of reactions 1~9, Kp is the main reaction equilibrium constant, C1~C4 are the correlation constants, and k i is the reaction rate constant, k i0 is the reaction rate pre-exponential factor, E a is the activation energy, b j is the adsorption constant, b j0 is the adsorption pre-exponential factor, Q j is the adsorption activation energy; P ST is the partial pressure of styrene, P EB is the partial pressure of ethylbenzene, P H2O is the water partial pressure, P H2 is the hydrogen partial pressure, P C2H4 is the ethylene partial pressure, P CH4 is the methane partial pressure, P CO is the partial pressure of carbon monoxide, P ISB is the partial pressure of cumene.

3. The simulation method for the reaction of ethylbenzene dehydrogenation to styrene according to claim 1, characterized in that: The material balance equation is: For impurity components that do not participate in the reaction, the flow rate change rate is 0: Where F is the molar flow rate of the component, r1~r9 are the reaction rates of reactions 1~9, r is the bed radius, L is the bed height, ρ is the catalyst packing density, and F Other F stands for impurities; ST is the molar flow rate of styrene, F TL is the molar flow rate of toluene, F EB is the molar flow rate of ethylbenzene, F BZ is the molar flow rate of benzene, F H2O is the water molar flow rate, F H2 is the hydrogen molar flow rate, F C2H4 is the molar flow rate of ethylene, F CH4 is the molar flow rate of methane, F CO is the molar flow rate of carbon monoxide, F CO2 is the molar flow rate of carbon dioxide, F ISB is the molar flow rate of cumene, F AMS is the molar flow rate of α-methylstyrene, F other It is an impurity that does not participate in the reaction.

4. The simulation method for the reaction of ethylbenzene dehydrogenation to styrene according to claim 1, characterized in that: The energy balance equation is: Where ΔH j is the molar reaction enthalpy change, j from 1 to 9 represents reactions 1 to 9 in sequence; C pi is the molar heat capacity at constant pressure, i from 1 to 19 represents the components ethylbenzene, styrene, toluene, benzene, water, hydrogen, ethylene, methane, carbon monoxide, carbon dioxide, isopropylbenzene, α-methylstyrene, o-xylene, m-xylene, p-xylene, o-diethylbenzene, m-diethylbenzene, p-diethylbenzene, and non-aromatics.

5. The simulation method for the reaction of ethylbenzene dehydrogenation to styrene according to claim 1, characterized in that: The momentum balance equation is: Where ε is the bed porosity, d p is the equivalent diameter of the specific surface area of ​​the catalyst particles, μ is the dynamic viscosity of the mixed gas, and u is the superficial velocity of the gas.

6. The simulation method for the reaction of ethylbenzene dehydrogenation to styrene according to claim 1, characterized in that: The reactor in the step five) includes a first reactor and a second reactor connected in series, and the reaction kinetics equation, material balance equation, energy balance equation and momentum balance equation are used to sequentially calculate the reaction product temperature, reaction product pressure and reaction product composition of the first reactor and the second reactor.

7. The simulation method for the dehydrogenation of ethylbenzene to produce styrene according to claim 6, characterized in that: The second reactor is provided with a heat exchanger, and the heat exchange temperature of the heat exchanger is calculated using the following formula: Where T in,steam is the steam inlet temperature, T out,steam is the steam outlet temperature, F steam is the steam molar flow rate, C p,steam is the molar heat capacity of steam at constant pressure, T in,Material is the inlet temperature of the reaction materials, T out,Material is the outlet temperature of the reaction materials, F Material is the molar flow rate of the reaction materials, C p,Material is the molar heat capacity of the reaction materials at constant pressure.

8. A simulation system for the dehydrogenation of ethylbenzene to produce styrene, characterized in that: include: Reaction kinetics module, used to calculate the reaction rates of each reaction in the reactor; Reaction material balance module, used to calculate the flow and composition of each reaction raw material and reaction product in the reactor; Reaction energy balance module, used to calculate the temperature change and reaction heat in the reactor; Reaction momentum balance module, used to calculate the pressure change in the reactor; The reaction of the reactor includes: Reaction 1: Ethylbenzene reacts to produce styrene and hydrogen; Reaction 2: Ethylbenzene reacts to produce benzene and ethylene; Reaction 3: Ethylbenzene and hydrogen react to form toluene and methane; Reaction 4: Styrene and hydrogen react to produce benzene and ethylene; Reaction 5: Styrene and hydrogen react to produce toluene and methane; Reaction 6: Methane and water react to produce carbon monoxide and hydrogen; Reaction 7: Carbon monoxide reacts with water to produce carbon dioxide and hydrogen; Reaction 8: Ethylene and water react to produce carbon monoxide and hydrogen; Reaction 9: Isopropylbenzene reacts to produce α-methylstyrene and hydrogen.

9. The simulation system for the reaction of ethylbenzene dehydrogenation to styrene according to claim 8, characterized in that: The reactor comprises a first reactor and a second reactor connected in series.

10. The simulation system for the reaction of ethylbenzene dehydrogenation to styrene according to claim 9, characterized in that: The second reactor is provided with a heat exchanger, and the system further comprises: The heat exchange calculation module is used to calculate the heat exchange temperature and heat exchange load of the heat exchanger.

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