A method and system for predicting carbon deposition in the electrolysis of CO by a solid oxide electrolyzer 2 in carbon deposition

Abstract

The present invention provides a method and system for predicting carbon deposition in the electrolysis of CO2 by a solid oxide electrolyzer, comprising the following steps: Step 1) constructing a kinetic equation model for the carbon deposition chemical reaction, which is used to calculate the amount of carbon deposition according to the reaction condition parameters during the electrolysis of CO2 by the solid oxide electrolyzer; Step 2) using the kinetic equation model of the carbon deposition chemical reaction to calculate the amount of carbon deposition in each region of the solid oxide electrolyzer during the electrolysis of CO2; obtaining the carbon deposition region and the amount of carbon deposition in the electrolysis of CO2 by the solid oxide electrolyzer. The carbon deposition prediction method of the present invention uses the kinetic equation model of the carbon deposition chemical reaction to simulate and calculate the carbon deposition process, and according to the calculation results, the parameters in the process of electrolyzing CO2 by the solid oxide electrolyzer can be adjusted to eliminate or reduce the carbon deposition generated during the electrolysis of CO2 by the solid oxide electrolyzer.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of electrolytic cells, and in particular to a method and system for predicting carbon deposition in the electrolysis of CO2 by a solid oxide electrolytic cell. Background Art

[0002] Solid oxide electrolysis cell (SOEC) electrolysis of CO 2 The development of clean and renewable energy can be combined with the utilization of carbon dioxide, which is efficient and clean. 2 One of the major problems is carbon deposition. Solid oxide electrolysis cells most commonly use Ni / YSZ as cathode electrode materials, and Ni is an excellent catalyst for the Boudourad reaction, which will cause carbon deposition on the electrode surface, thus affecting the performance and life of the electrolysis cell. Boudourad reaction equation:

[0003]

[0004] At present, the solid oxide electrolysis cell is being studied for CO 2 The carbon deposition problem can be divided into the following points: First, the form of carbon deposition is verified based on experiments; second, the possibility of carbon deposition is verified based on models, mainly one-dimensional, two-dimensional, three-dimensional models and thermodynamic models, and there are few kinetic models to describe the amount of carbon deposition and the specific location of carbon deposition; third, the influence of operating conditions on carbon deposition is verified, which is generally experimental verification or thermodynamic model verification. The experiment is cumbersome and cannot analyze the carbon deposition inside the electrolytic cell, while the thermodynamic model describes the possibility of carbon deposition and cannot accurately calculate the amount of carbon deposition. Therefore, it is urgent to establish a systematic model to predict the specific amount of carbon deposition and reduce or eliminate carbon deposition according to the operating conditions. Summary of the invention

[0005] In order to electrolyze CO 2 The amount of carbon deposits generated can be predicted, and then the carbon deposits can be eliminated by adjusting the reaction parameters. The present invention proposes a solid oxide electrolysis cell for electrolyzing CO 2 Carbon deposition prediction method and system. The present invention adopts the following technical solutions:

[0006] A method for predicting carbon deposition in electrolyzing CO2 in a solid oxide electrolytic cell comprises the following steps:

[0007] Step 1) constructing a kinetic equation model of the carbon deposition chemical reaction, wherein the kinetic equation model of the carbon deposition chemical reaction is used to electrolyze CO in a solid oxide electrolysis cell. 2 The amount of carbon deposits is calculated based on the reaction condition parameters during the process;

[0008] Step 2) The kinetic equation model of carbon deposition chemical reaction is used to calculate the carbon deposition amount in each area of ​​the solid oxide electrolytic cell during the electrolysis of CO2; 2 The carbon deposit area and amount.

[0009] Optionally, the kinetic equation model of the carbon deposition chemical reaction includes:

[0010] Carbon deposition reaction rate equation for electrolysis of CO in a solid oxide electrolysis cell 2 The carbon deposition reaction rate is calculated based on the reaction condition parameters during the process.

[0011] Optionally, the kinetic equation model of the carbon deposition chemical reaction also includes:

[0012] Porosity differential equation for CO electrolysis in solid oxide electrolysis cells 2 The porosity of the electrode material is calculated based on the carbon deposition reaction rate during the process.

[0013] Optionally, the kinetic equation model of the carbon deposition chemical reaction also includes:

[0014] Catalyst activity differential equation for CO electrolysis in solid oxide electrolyzers 2 The catalyst activity is calculated from the carbon deposition reaction rate during the process.

[0015] Optionally, the reaction condition parameters include operating condition parameters and structural parameters;

[0016] The operating condition parameters include: temperature, pressure, air intake, and operating current;

[0017] The structural parameters include: cathode material porosity, electrode thickness, electrolyte thickness, electrolytic cell rib width, and electrolytic cell flow channel length.

[0018] Optionally, the kinetic equation model of the carbon deposition chemical reaction also includes:

[0019] The mass conservation equation is used to simulate the electrolysis of CO in solid oxide electrolysis cells. 2 Diffusion of substances in the process;

[0020] Butler–Folmer equation for simulation of CO electrolysis in solid oxide electrolysis cells 2 The electrochemical reaction process in the process;

[0021] Energy conservation equations for simulating CO electrolysis in solid oxide electrolysis cells 2 Energy transfer process in the process;

[0022] Momentum conservation equation for simulation of CO electrolysis in solid oxide electrolysis cells 2The flow process in the process.

[0023] A solid oxide electrolysis cell for electrolysis of CO 2 The carbon deposition control method comprises the following steps:

[0024] The solid oxide electrolysis cell is used to electrolyze CO 2 Predict the carbon deposition of the process;

[0025] When the carbon deposition amount calculated by the kinetic equation model of the carbon deposition chemical reaction is greater than the carbon deposition amount threshold, the solid oxide electrolysis cell is used to electrolyze CO 2 The operating condition parameters in the process are adjusted, and then the carbon deposit amount is calculated by the kinetic equation model of the carbon deposit chemical reaction, and the above process is repeated until the carbon deposit amount is less than the carbon deposit amount threshold;

[0026] The operating condition parameters include temperature, pressure, air intake, and operating current.

[0027] Optionally, the carbon deposit amount threshold is 0.

[0028] Optionally, the method further comprises calculating the electrolysis efficiency according to the kinetic equation model of the carbon deposition chemical reaction, and electrolyzing CO in the solid oxide electrolysis cell according to the calculation result. 2 The reaction condition parameters are adjusted during the process until the electrolysis efficiency reaches the maximum.

[0029] The structural design method of a solid oxide electrolytic cell comprises the following steps:

[0030] When the carbon deposition amount calculated by the kinetic equation model of the carbon deposition chemical reaction is greater than 0, the solid oxide electrolysis cell is used to electrolyze CO 2 The structural parameters of the electrolytic cell are adjusted during the process, and then the carbon deposition amount is calculated by the kinetic equation model of the carbon deposition chemical reaction, and the above process is repeated until the carbon deposition amount is 0; and then the structural parameters of the carbon deposition amount 0 calculated by the kinetic equation model of the carbon deposition chemical reaction are used to design the solid oxide electrolytic cell;

[0031] The electrolytic cell structural parameters include cathode material porosity, electrode thickness, electrolyte thickness, electrolytic cell rib width, and electrolytic cell flow channel length.

[0032] A solid oxide electrolysis cell for electrolysis of CO 2 Carbon deposition prediction system, including:

[0033] The carbon deposition prediction module uses a kinetic equation model of the carbon deposition chemical reaction to calculate the carbon deposition in each area of ​​the solid oxide electrolytic cell during the electrolysis of CO. 2 The amount of carbon deposits in the process; the solid oxide electrolysis cell electrolysis CO 2The carbon deposit area and amount.

[0034] Optionally, the solid oxide electrolysis cell electrolyzes CO 2 The carbon deposition prediction system also includes:

[0035] Quality simulation module for simulating the electrolysis of CO in solid oxide electrolysis cells 2 Diffusion of substances in the process;

[0036] Current and polarization simulation module for simulating the electrolysis of CO in solid oxide electrolysis cells 2 The electrochemical reaction process in the process;

[0037] Energy simulation module for simulating the electrolysis of CO in solid oxide electrolysis cells 2 Energy transfer process in the process;

[0038] Momentum simulation module, used to simulate the electrolysis of CO in solid oxide electrolysis cells 2 The flow process in the process.

[0039] Optionally, the quality simulation module includes:

[0040] The gas channel material simulation submodule is used to simulate the solid oxide electrolysis cell electrolysis of CO 2 Diffusion process of substances in gas channels;

[0041] The electrode material simulation submodule is used to simulate the electrolysis of CO in solid oxide electrolysis cells. 2 Diffusion processes of substances in porous electrodes.

[0042] Optionally, the energy simulation calculation module includes:

[0043] The gas channel energy simulation submodule is used to simulate the electrolysis of CO in solid oxide electrolysis cells. 2 Heat conduction and convection processes in the gas channel during the process;

[0044] The electrode energy simulation submodule is used to simulate the electrolysis of CO in solid oxide electrolysis cells. 2 Heat conduction process of process electrode.

[0045] Optionally, the momentum simulation module includes:

[0046] The gas channel momentum simulation submodule is used to simulate the electrolysis of CO in solid oxide electrolysis cells. 2 Flow process in the gas channel during the process;

[0047] The electrode momentum simulation submodule is used to simulate the electrolysis of CO in solid oxide electrolysis cells. 2 Flow processes within the process electrode.

[0048] Optionally, the solid oxide electrolysis cell electrolyzes CO 2 The carbon deposition prediction system also includes:

[0049] The carbon deposition control module is used to control the carbon deposition amount calculated by the kinetic equation model of the carbon deposition chemical reaction when it is greater than the carbon deposition amount threshold. 2 The reaction condition parameters in the process are adjusted, and then the carbon deposit amount is calculated through the kinetic equation model of the carbon deposit chemical reaction until the carbon deposit amount is less than the carbon deposit amount threshold;

[0050] The reaction condition parameters include temperature, pressure, air intake, and operating current.

[0051] Optionally, the solid oxide electrolysis cell electrolyzes CO 2 The carbon deposition prediction system also includes:

[0052] Solid oxide electrolytic cell design module, when the carbon deposition amount calculated by the kinetic equation model of carbon deposition chemical reaction is greater than 0, the solid oxide electrolytic cell electrolysis CO 2 The reaction condition parameters in the process are adjusted, and then the carbon deposit amount is calculated through the kinetic equation model of the carbon deposit chemical reaction until the carbon deposit amount is 0;

[0053] The reaction condition parameters include cathode material porosity, electrode thickness, electrolyte thickness, electrolytic cell rib width, and electrolytic cell flow channel length.

[0054] The present invention has the following beneficial effects:

[0055] 1. The carbon deposition prediction method of the present invention uses the kinetic equation model of carbon deposition chemical reaction to simulate the carbon deposition process. According to the calculation results, the solid oxide electrolysis cell CO electrolysis can be used to predict the carbon deposition process. 2 Adjust the process parameters to eliminate or reduce the CO 2 Carbon deposits generated during the process.

[0056] 2. The carbon deposition prediction method of the present invention incorporates the differential equations of porosity and catalyst activity, which can effectively reflect the influence of carbon deposition on the electrolytic cell and more truly reflect the influence of carbon deposition on porosity and catalyst activity, and can calculate the real-time changes in carbon deposition rate.

[0057] 3. The control system can effectively reflect the amount of carbon deposits; through system control, it can effectively reduce the occurrence of carbon deposits and improve system efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0059] Figure 1 This is a schematic diagram of the calculation domain of the solid oxide electrolysis cell;

[0060] Figure 2 Flow chart for controlling carbon deposits.

[0061] Figure 3 Carbon deposition at different gas flow rates.

[0062] Figure 4 Carbon deposition conditions at different electrode porosities. DETAILED DESCRIPTION

[0063] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] Example 1

[0065] The present invention proposes a solid oxide electrolysis cell for electrolyzing CO 2 A single channel is selected as the calculation domain, including the connector, cathode, cathode diffusion layer, electrolyte membrane, and gas channel. Because the electrolytic cell is composed of multiple repeating units, one of the units is selected for calculation, and the calculation domain is selected as the single channel in the electrolytic cell. Its structure is shown in Figure 1 The carbon deposition prediction method for the three-dimensional model of the electrolytic cell includes the following steps:

[0066] Step 1) constructing a kinetic equation model of a carbon deposition chemical reaction, wherein the kinetic equation model of a carbon deposition chemical reaction is used to calculate the amount of carbon deposition according to reaction condition parameters during the electrolysis of CO2 in a solid oxide electrolysis cell;

[0067] Step 2) Use the kinetic equation model of carbon deposition chemical reaction to calculate the various regions of the solid oxide electrolytic cell during the electrolysis of CO 2 The amount of carbon deposits in the process; the solid oxide electrolysis cell electrolysis CO 2 The carbon deposit area and amount.

[0068] The kinetic equation model of the carbon deposition chemical reaction is established according to the Boudourad reaction equation:

[0069]

[0070] The kinetic equation model of carbon deposition chemical reaction includes:

[0071] Carbon deposition reaction rate equation for electrolysis of CO in a solid oxide electrolysis cell 2 The reaction rate of carbon deposition is calculated based on the reaction condition parameters in the process;

[0072] Porosity differential equation for CO electrolysis in solid oxide electrolysis cells 2 The porosity of the electrode material is calculated based on the carbon deposition reaction rate during the process.

[0073] Differential equations of catalyst activity for CO electrolysis in solid oxide electrolyzers 2 The catalytic activity is calculated from the carbon deposition reaction rate during the process.

[0074] In this embodiment, the carbon deposition reaction rate equation is first established as the carbon deposition chemical reaction equation:

[0075]

[0076] in is the carbon deposition reaction rate; is the reaction constant for the cracking of CO to produce C; is the CO adsorption reaction constant; is the pressure of CO; is the threshold constant for carbon deposition; It is CO 2 pressure; is the O intermediate reaction constant.

[0077] According to the definition and calculation method of chemical reaction rate, the above carbon deposition reaction rate is affected by gas pressure. , The impact of , The solid oxide electrolysis cell electrolyzes CO 2 Effect of reaction process on CO electrolysis in solid oxide electrolysis cell 2 The factors affecting the reaction mainly include: temperature, gas pressure, air intake, working voltage, cathode material porosity, cathode active layer thickness, diffusion layer thickness, electrolyte thickness, and electrolytic cell flow channel length. Some of the above parameters are 2The parameters that are adjusted in real time during the process include temperature, gas pressure, air intake, and working voltage. These parameters are working condition parameters. Other parameters are determined when the solid oxide electrolytic cell is designed and manufactured and cannot be changed, including cathode material porosity, cathode active layer thickness, diffusion layer thickness, electrolyte thickness, and electrolytic cell flow channel length. These parameters are electrolytic cell structural parameters.

[0078] In this embodiment, the catalyst activity differential equation is:

[0079]

[0080]

[0081] a is the catalyst activity; is the carbon deposition reaction rate; C c is the carbon deposit concentration; ka is the catalyst activity decay constant, R is the gas constant; T is the temperature.

[0082] In this embodiment, the porosity differential equation is:

[0083]

[0084] is the electrode porosity; is the carbon deposition reaction rate; Mc is the molar mass of carbon; is the carbon deposit density.

[0085] Electrochemical reaction CO electrolysis 2 During the process, CO is generated. When the local concentration of CO in the cathode material is too high, carbon deposits will form on the cathode material. The porosity differential equation and catalyst activity differential equation mentioned above can be used to calculate the changes in the porosity and catalyst activity of the cathode material as carbon deposits form and accumulate. The porosity will affect the diffusion of CO, and the catalyst activity will affect the speed of the electrochemical reaction. Therefore, the gas pressure used to calculate the carbon deposition reaction rate after carbon deposition is generated is , Therefore, the kinetic equation model of the carbon deposition chemical reaction in this embodiment can calculate the real-time change of the carbon deposition reaction rate over time.

[0086] Due to the above parameters affecting the carbon deposition reaction rate, the solid oxide electrolysis cell electrolyzes CO 2 In order to determine the various parameters in the carbon deposition reaction rate through simulation calculation, the present embodiment proposes the following set of equations in conjunction with the kinetic equation model of the above carbon deposition chemical reaction.

[0087] Solid oxide electrolysis cell for CO electrolysis 2The material diffusion process in the gas channel is calculated using the following mass conservation equation:

[0088]

[0089] is the density; U is the velocity term;

[0090] Solid oxide electrolysis cell for CO electrolysis 2 The material diffusion process in the porous electrode is calculated using the following mass conservation equation:

[0091]

[0092] is the density; U is the velocity term; Qm is the mass source term.

[0093] The relationship between current and polarization is calculated using the Butler-Volmer equation:

[0094]

[0095] Where i is the current density; is the exchange current density coefficient; n is the number of transferred electrons; F is the Faraday constant; is the electrode polarization; R is the gas constant; T is the temperature; i 0 is the exchange current density. Q is the current source term.

[0096] Solid oxide electrolysis cell for CO electrolysis 2 The heat conduction and convection processes in the gas channel during the process are calculated using the following energy conservation equation:

[0097]

[0098] in, is density; Cp is heat capacity; T is temperature; is the thermal conductivity.

[0099] Solid oxide electrolysis cell for CO electrolysis 2 The heat conduction process of the process electrode is calculated using the following energy conservation equation:

[0100]

[0101] in, is density; Cp is heat capacity; T is temperature; is the thermal conductivity; Qe is the heat source term.

[0102] The momentum simulation module includes:

[0103] Solid oxide electrolysis cell for CO electrolysis 2 The flow process in the gas channel during the process is calculated using the following momentum conservation equation:

[0104]

[0105] Where U is the velocity term; p is the pressure; It's viscosity.

[0106] Solid oxide electrolysis cell for CO electrolysis 2 The flow process in the process electrode is calculated using the following momentum conservation equation:

[0107]

[0108] Among them, U is the velocity term; is the porosity; is the density; p is the pressure; is viscosity; is the permeability; Qm is the mass source term.

[0109] The gas concentrations in the flow channel and the electrode region can be calculated using the above equations, and the carbon deposition reaction rate can be calculated by substituting the gas concentrations into the above carbon deposition reaction model.

[0110] Example 2

[0111] By using the prediction system in Example 1, the reaction parameters can be adjusted to control carbon deposition. The process of controlling carbon deposition is as follows: Figure 2 As shown:

[0112] The amount of carbon deposits is connected to the control module as an output result, and a threshold value (i.e., the amount of carbon deposits is 0) is set for comparison. If the amount of carbon deposits is greater than 0, the operating conditions (temperature, pressure, current, intake volume, the adjustment parameters are not unique, it may be one parameter, it may be multiple parameters adjusted together), and then the calculation is performed again until the amount of carbon deposits is 0, indicating that there is no carbon deposits. During the adjustment period, the operating conditions are set within a certain range.

[0113] When some solid oxide electrolytic cells cannot prevent carbon deposition by adjusting the operating conditions due to defects in structural size and porosity, the electrolysis efficiency is connected to the control module as an output result. By setting a certain threshold (desired efficiency value) and adjusting the operating parameters, the electrolysis efficiency is maintained at the highest level. The calculation method of electrolysis efficiency is as follows:

[0114]

[0115] in is the electrolysis efficiency; V_cell is the electrolysis voltage; V_rev is the reversible voltage; eta_th is the thermal efficiency.

[0116] Example 3

[0117] By using the prediction system in Example 1, the structural parameters of the solid oxide electrolytic cell can be adjusted, thereby designing a solid oxide electrolytic cell without carbon deposits.

[0118] The carbon deposit amount is connected to the control module as an output result, and a threshold value (i.e., the carbon deposit amount is 0) is set for comparison. If the carbon deposit amount is greater than 0, the structural parameters (the porosity of the cathode material, the thickness of the electrode and electrolyte, the width of the electrolytic cell ribs, and the length of the electrolytic cell flow channel) are adjusted, and then the calculation is performed again until the carbon deposit amount is 0, indicating that there is no carbon deposit. Then, the electrolytic cell equipment is selected and integrated according to the calculated material properties and electrolytic cell structure.

[0119] Example 4

[0120] This embodiment proposes a solid oxide electrolysis cell for electrolyzing CO 2 Carbon deposit control system, including:

[0121] Carbon deposition model module for electrolysis of CO in solid oxide electrolysis cells 2 The amount of carbon deposits is calculated based on the reaction condition parameters during the process;

[0122] The control module is used to control the solid oxide electrolysis cell to electrolyze CO when the carbon deposition amount calculated by the kinetic equation model of the carbon deposition chemical reaction is greater than the carbon deposition amount threshold. 2 The reaction condition parameters in the process are adjusted, and then the carbon deposit amount is calculated through the kinetic equation model of the carbon deposit chemical reaction until the carbon deposit amount is less than the carbon deposit threshold.

[0123] Quality simulation module for simulating CO electrolysis in solid oxide electrolyzers 2 Diffusion of substances in the process;

[0124] Current and polarization simulation module for simulating CO electrolysis in solid oxide electrolysis cells 2 Electrochemical reactions in the process;

[0125] Energy simulation module for simulating CO electrolysis in solid oxide electrolysis cells 2 Energy transfer process in the process;

[0126] Momentum simulation module for simulating CO electrolysis in solid oxide electrolysis cells 2 The flow process in the process.

[0127] The carbon deposition model module and the control module in this system calculate the carbon deposition amount and adjust the parameters according to the method in Example 1. The mass simulation module, the current and polarization simulation module, the energy simulation module, and the momentum simulation module are used to realize the coupling between charge, matter, energy, and fluid flow.

[0128] The quality simulation module includes:

[0129] Gas channel material simulation submodule for simulating CO electrolysis in solid oxide electrolysis cells 2 The material diffusion process in the gas channel is calculated using the mass conservation equation:

[0130]

[0131] is the gas density; U is the velocity term;

[0132] Electrode material simulation submodule, used to simulate CO electrolysis in solid oxide electrolysis cells 2 The diffusion process of substances in a porous electrode is calculated using the mass conservation equation:

[0133]

[0134] is the gas density; U is the velocity term; Qm is the mass source term.

[0135] Current and polarization simulation module, the relationship between current and polarization is calculated using the Butler-Volmer equation:

[0136]

[0137] Where i is the current density; is the exchange current density coefficient; n is the number of transferred electrons; F is the Faraday constant; is the electrode polarization; R is the gas constant; T is the operating temperature; i 0 is the exchange current density. Q is the current source term.

[0138] The energy simulation module includes:

[0139] Gas channel energy simulation submodule for simulating CO electrolysis in solid oxide electrolysis cells 2 The heat conduction and heat convection process in the gas channel during the process is calculated using the energy conservation equation:

[0140]

[0141] in, is the gas density; Cp is the gas heat capacity; T is the operating temperature; is the thermal conductivity of gas.

[0142] Electrode energy simulation submodule, used to simulate CO electrolysis in solid oxide electrolysis cells 2 The heat conduction process of the process electrode is calculated using the energy conservation equation:

[0143]

[0144] in, is density; Cp is heat capacity; T is temperature; is the thermal conductivity; Qe is the heat source term.

[0145] The momentum simulation module includes:

[0146] Gas channel momentum simulation submodule for simulating CO electrolysis in solid oxide electrolysis cells 2 The flow process in the gas channel during the process; calculated using the momentum conservation equation

[0147]

[0148] Electrode momentum simulation submodule for simulating CO electrolysis in solid oxide electrolysis cells 2 Flow process in the process electrode. Calculated using the momentum conservation equation:

[0149]

[0150] Among them, U is the velocity term; is the porosity; is the gas density; p is the gas pressure; is viscosity; is the permeability; Qm is the mass source term.

[0151] Test example

[0152] Figure 3 This is one of the schematic diagrams of carbon deposition control results: working voltage 1.4V, temperature 750℃, pressure 1 atmosphere, cathode material porosity 0.35, cathode active layer thickness 10 microns, diffusion layer thickness 200 microns, electrolyte thickness 10 microns, electrolytic cell flow channel length 15cm. Under the premise of keeping other conditions the same, the intake air flow rate is changed through system control. The carbon deposition amount is calculated using the kinetic equation model of the carbon deposition chemical reaction in Example 1. The results show that as the flow rate increases, the carbon deposition gradually decreases.

[0153] Figure 4This is one of the schematic diagrams of the equipment selection results: the flow rate is adjusted to 4m / s, and the other conditions are the same as the above test example. In addition, different porosities are changed. Finally, it is concluded that there is little carbon deposition when the porosity of the cathode material is above 0.45. Therefore, when it comes to the electrolytic cell structure, a cathode material with a porosity of more than 0.45 can be selected.

[0154] The above is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A method for predicting carbon deposition during the electrolysis of CO in a solid oxide electrolysis cell 2 ​ It is characterized in that It includes the following steps: Step 1) Construct a kinetic equation model for the carbon deposition chemical reaction, and the kinetic equation model for the carbon deposition chemical reaction is used to calculate the carbon deposition amount according to the reaction condition parameters during the electrolysis of CO in the solid oxide electrolytic cell 2 process; Step 2) Use the kinetic equation model of the carbon deposition chemical reaction to calculate the carbon deposition amount in each region of the solid oxide electrolytic cell during the electrolysis of CO 2 process; Obtain the carbon deposition area and carbon deposition amount of solid oxide electrolytic cell electrolyzing CO 2 ; The kinetic equation model of the carbon deposition chemical reaction includes: The carbon deposition reaction rate equation is used to calculate the carbon deposition reaction rate based on the reaction condition parameters during the electrolysis of CO in a solid oxide electrolyzer 2 during the process; Porosity differential equation for calculating the porosity of an electrode material based on the carbon deposition reaction rate during the electrolysis of CO in a solid oxide electrolytic cell 2 during the process; Differential equation of catalyst activity, used to calculate the catalyst activity according to the carbon deposition reaction rate during the electrolysis of CO in a solid oxide electrolyzer 2 during the process; The carbon deposition chemical reaction equation is: Among them is the coking reaction rate; is the reaction constant for the production of C by CO cracking; is the CO adsorption reaction constant; is the pressure of CO; is the threshold constant for carbon deposition; is CO 2 pressure; is the O intermediate reaction constant; The porosity differential equation is: Among them is the electrode porosity; is the carbon deposition reaction rate; Mc is the molar mass of carbon; is the carbon deposition density; The catalyst activity differential equation is: where a is the catalyst activity; is the carbon deposition reaction rate; C c is the carbon deposition concentration; ka is the decay constant of the catalyst activity, R is the gas constant; T is the temperature.

2. Method for predicting carbon deposition in the electrolysis of CO in a solid oxide electrolytic cell according to claim 1 2 for carbon deposition prediction It is characterized in that The reaction condition parameters include working condition parameters and electrolytic cell structure parameters; The working condition parameters include: temperature, gas pressure, intake air volume, working voltage; The electrolytic cell structure parameters include: cathode material porosity, cathode active layer thickness, diffusion layer thickness, electrolyte thickness, electrolytic cell flow channel length.

3. Method for predicting carbon deposition during electrolysis of CO in the solid oxide electrolytic cell according to claim 1 2 ​ It is characterized in that The kinetic equation model of the carbon deposition chemical reaction further includes: The mass conservation equation is used to simulate the mass diffusion process during the electrolysis of CO in a solid oxide electrolyzer 2 process; The Butler–Volmer equation, which is used to simulate the electrochemical reactions during the electrolysis of CO in a solid oxide electrolysis cell 2 during the process; The energy conservation equation is used to simulate the energy transfer process during the electrolysis of CO in a solid oxide electrolyzer 2 process; The momentum conservation equation is used to simulate the flow process during the electrolysis of CO in a solid oxide electrolyzer. 2 ​ 4. A method for controlling carbon deposition in the electrolysis of CO by a solid oxide electrolyzer 2 ​ It is characterized in that It includes the following steps: Predict the carbon deposition during the electrolysis of CO in a solid oxide electrolytic cell by using any one of the methods according to claims 1 to 3 2 during the process; When the amount of carbon deposition calculated by the kinetic equation model of the carbon deposition chemical reaction is greater than the carbon deposition amount threshold, the operating condition parameters in the process of electrolyzing CO by the solid oxide electrolytic cell are adjusted, and then the amount of carbon deposition is calculated through the kinetic equation model of the carbon deposition chemical reaction. The above process is cycled until the amount of carbon deposition is less than the carbon deposition amount threshold; 2 The operating condition parameters during the process of electrolyzing CO are adjusted, and then the amount of carbon deposition is calculated through the kinetic equation model of the carbon deposition chemical reaction. The above process is cycled until the amount of carbon deposition is less than the carbon deposition amount threshold; The working condition parameters include temperature, gas pressure, intake air volume, working voltage.

5. Method for controlling carbon deposition in electrolyzing CO of solid oxide electrolytic cell according to claim 4 2 ​ It is characterized in that The carbon deposition amount threshold is 0.

6. Method for controlling carbon deposition in electrolyzing CO of solid oxide electrolytic cell according to claim 4 2 ​ It is characterized in that The method further includes calculating the electrolysis efficiency according to the kinetic equation model of the carbon deposition chemical reaction, and adjusting the reaction condition parameters in the process of electrolyzing CO by the solid oxide electrolytic cell according to the calculation result until the electrolysis efficiency reaches the maximum. 2 The reaction condition parameters in the process of electrolyzing CO by the solid oxide electrolytic cell are adjusted until the electrolysis efficiency reaches the maximum.

7. A structural design method of a solid oxide electrolytic cell It is characterized in that It includes the following steps: Predict the carbon deposition during the electrolysis of CO in a solid oxide electrolysis cell by any one of the methods recited in claims 1 to 3 2 process; When the carbon deposition amount calculated by the kinetic equation model of the carbon deposition chemical reaction is greater than 0, the structure parameters of the electrolytic cell in the process of electrolyzing CO in the solid oxide electrolytic cell are adjusted, and then the carbon deposition amount is calculated through the kinetic equation model of the carbon deposition chemical reaction, and the above process is cycled until the carbon deposition amount is 0; 2 When the carbon deposition amount calculated by the kinetic equation model of the carbon deposition chemical reaction is greater than 0, the structure parameters of the electrolytic cell in the process of electrolyzing CO in the solid oxide electrolytic cell are adjusted, and then the carbon deposition amount is calculated through the kinetic equation model of the carbon deposition chemical reaction, and the above process is cycled until the carbon deposition amount is 0; Design a solid oxide electrolytic cell with structural parameters of carbon deposition amount of 0 calculated by using the kinetic equation model of the carbon deposition chemical reaction; The electrolytic cell structure parameters include cathode material porosity, electrode thickness, electrolyte thickness, electrolytic cell rib width, electrolytic cell flow channel length.

8. A carbon deposition prediction system for electrolyzing CO in a solid oxide electrolytic cell 2 ​ It is characterized in that It includes: A carbon deposition prediction module, and the carbon deposition model module calculates the carbon deposition amount in each region of the solid oxide electrolytic cell during the electrolysis of CO by using a kinetic equation model of the carbon deposition chemical reaction 2 process; Obtain the carbon deposition region and carbon deposition amount of solid oxide electrolytic cell electrolyzing CO 2 ; The kinetic equation model of the carbon deposition chemical reaction includes: A carbon deposition reaction rate equation for calculating the carbon deposition reaction rate according to the reaction condition parameters during the electrolysis of CO in a solid oxide electrolytic cell 2 during the process; A porosity differential equation for calculating the porosity of an electrode material based on the carbon deposition reaction rate during the electrolysis of CO in a solid oxide electrolytic cell 2 during the process; The differential equation of catalyst activity is used to calculate the catalyst activity according to the carbon deposition reaction rate during the electrolysis of CO in a solid oxide electrolytic cell 2 during the process; The carbon deposition chemical reaction equation is: wherein is the carbon deposition reaction rate; is the reaction constant for the production of C by CO cracking; is the CO adsorption reaction constant; is the pressure of CO; is the threshold constant for carbon deposition; is CO 2 pressure; is the O intermediate reaction constant; The porosity differential equation is: wherein is the electrode porosity; is the coking reaction rate; Mc is the molar mass of carbon; is the coking density; The catalyst activity differential equation is: where a is the catalyst activity; is the carbon deposition reaction rate; C c is the carbon deposition concentration; ka is the decay constant of the catalyst activity, R is the gas constant; T is the temperature.

9. The system according to claim 8 It is characterized in that The carbon deposition prediction system for electrolyzing CO in the solid oxide electrolytic cell further includes: 2 ​ A mass simulation module for simulating and calculating the mass diffusion process during the electrolysis of CO in a solid oxide electrolytic cell 2 process; A current and polarization simulation module is used to simulate and calculate the electrochemical reactions during the electrolysis of CO in a solid oxide electrolyzer. 2 during the process; An energy simulation module for simulating and calculating the energy transfer process during the electrolysis of CO in a solid oxide electrolyzer 2 process; A momentum simulation module for simulating and calculating the flow process during the electrolysis of CO in a solid oxide electrolysis cell 2 process.

10. The system according to claim 9 It is characterized in that The mass simulation module includes: A gas channel substance simulation sub-module is used to simulate and calculate the electrolysis of CO in a solid oxide electrolytic cell 2 and the substance diffusion process in the gas channel; The electrode material simulation sub-module is used to simulate and calculate the mass diffusion process of CO in the solid oxide electrolytic cell in the porous electrode. 2 ​ 11. The system according to claim 9 It is characterized in that The energy simulation module includes: A gas channel energy simulation sub-module for simulating and calculating the heat conduction and heat convection processes in the gas channel during the electrolysis of CO in a solid oxide electrolyzer 2 process; The electrode energy simulation sub-module is used to simulate and calculate the heat conduction process of the electrode during the electrolysis of CO in the solid oxide electrolytic cell. 2 ​ 12. The system according to claim 9 It is characterized in that The momentum simulation module includes: Gas channel momentum simulation sub-module, used to simulate the flow process in the gas channel during the electrolysis of CO in a solid oxide electrolytic cell 2 during the process; An electrode momentum simulation sub-module, which is used to simulate and calculate the flow process inside the electrode during the electrolysis of CO in a solid oxide electrolytic cell. 2 ​ 13. The system according to claim 9 It is characterized in that The carbon deposition prediction system for electrolyzing CO in the solid oxide electrolytic cell further includes: 2 ​ The carbon deposition control module, when the calculated carbon deposition amount obtained from the kinetic equation model of the carbon deposition chemical reaction is greater than the carbon deposition amount threshold, electrolyzes CO in the solid oxide electrolytic cell 2 adjusts the reaction condition parameters during the process, and then calculates the carbon deposition amount through the kinetic equation model of the carbon deposition chemical reaction until the carbon deposition amount is less than the carbon deposition amount threshold; The reaction condition parameters include temperature, pressure, intake air volume, working current.

14. The system according to claim 9 It is characterized in that The carbon deposition prediction system for electrolyzing CO by the solid oxide electrolytic cell further includes: 2 ​ Solid oxide electrolyzer design module, when the amount of carbon deposition calculated by the kinetic equation model of the carbon deposition chemical reaction is greater than 0, the reaction condition parameters during the electrolysis of CO in the solid oxide electrolyzer are adjusted, and then the amount of carbon deposition is calculated through the kinetic equation model of the carbon deposition chemical reaction until the amount of carbon deposition is 0; 2 The reaction condition parameters during the electrolysis of CO in the solid oxide electrolyzer are adjusted, and then the amount of carbon deposition is calculated through the kinetic equation model of the carbon deposition chemical reaction until the amount of carbon deposition is 0; The reaction condition parameters include cathode material porosity, electrode thickness, electrolyte thickness, electrolytic cell rib width, electrolytic cell flow channel length.

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