Preparation method of SOEC stack-based system for preparing wide-ratio synthesis gas and the system

Abstract

This invention discloses a wide-ratio syngas preparation system based on an SOEC stack, comprising a gas supply unit connected sequentially to an SOEC unit and a tail gas treatment unit via pipelines. The SOEC unit includes an SOEC stack, which comprises several individual cells, each including a fuel electrode, an electrolyte, and an oxygen electrode. The H2 / CO ratio prepared by this invention can be precisely and over a wide range. The target gas composition can be rapidly adjusted by regulating the gas ratio and electrolysis parameters, making it suitable for the differentiated requirements of feedstock gas composition in various downstream reaction processes, such as Fischer-Tropsch synthesis, methanol synthesis, and methane synthesis. This invention also discloses a method for preparing the wide-ratio syngas system based on an SOEC stack.

Description

Technical Field

[0001] This invention belongs to the field of solid oxide electrolytic cell co-electrolysis technology, and relates to a wide-ratio syngas preparation system based on SOEC stack. This invention also relates to the preparation method of the above-mentioned wide-ratio syngas preparation system based on SOEC stack. Background Technology

[0002] Solid oxide electrolyzers (SOECs) can utilize renewable electricity and external waste heat to convert water (H2O) and carbon dioxide (CO2) into syngas, which consists of hydrogen (H2) and carbon monoxide (CO). The generated syngas can then be integrated with downstream chemical processes to synthesize high-value-added chemical products such as methane, methanol, and dimethyl ether, achieving a low-carbon end-to-end green electricity-chemicals chain.

[0003] SOEC, powered by electricity and heat, reduces the inlet H2O / CO2 to the outlet H2 / CO. The H2 / CO ratio in the outlet syngas can be adjusted by regulating the gas composition and flow rate at the SOEC inlet, as well as the battery's operating state (current density / voltage), to meet the feedstock requirements of downstream synthetic fuels. Different chemicals require different syngas ratios. To match SOEC technology with downstream chemical synthesis, a wide range of adjustable syngas ratios at the SOEC outlet is necessary. However, in existing technologies, the SOEC outlet syngas ratio is difficult to determine, making it challenging to adapt to downstream chemical synthesis needs. Therefore, a method for controlling the H2 / CO ratio in the outlet syngas is needed to meet the synthesis requirements of different chemicals.

[0004] Therefore, based on existing industrial-sized batteries, it is of great significance to explore the impact of operating conditions on the proportion of syngas discharged from SOEC co-electrolysis and to establish control methods to meet the needs of multiple synthesis scenarios. Summary of the Invention

[0005] The purpose of this invention is to provide a wide-ratio syngas preparation system based on SOEC stacks. By adjusting the SOEC operating parameters, the H2 / CO ratio in the outlet syngas can be precisely adjusted to meet the diverse requirements of various downstream chemical processes for feedstock gas composition.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned SOEC-based wide-scale synthesis gas preparation system.

[0007] The technical solution adopted in this invention is a wide-ratio synthesis gas preparation system based on SOEC stack, including a gas supply unit, which is connected to the SOEC unit and the tail gas treatment unit in sequence through pipelines; the SOEC unit includes an SOEC stack, which includes several single cells, and each single cell includes a fuel electrode, an electrolyte and an oxygen electrode.

[0008] The invention is further characterized by: The gas supply unit includes a steam generator, the inlet of which is connected to the first inlet, the second inlet and the third inlet via pipes, and the outlet of which is connected to the first heater. A water pump is installed between the first inlet and the steam generator; a first flow meter is installed between the second inlet and the steam generator; and a second flow meter is installed between the third inlet and the steam generator. The gas supply unit also includes an air compressor pump, the output of which is connected to a second heater via a pipe.

[0009] The first heater is connected to the fuel electrode via a pipe, and the second heater is connected to the oxygen electrode via a pipe.

[0010] The exhaust gas treatment unit includes a condensation and H2O removal device. The inlet of the condensation and H2O removal device is connected to the fuel electrode, and the outlet of the condensation and H2O removal device outputs syngas. The outlet of the condensation and H2O removal device is also connected to a gas phase detection device.

[0011] Another technical solution adopted in this invention is a method for preparing a wide-ratio syngas preparation system based on an SOEC fuel cell stack. The method specifically includes the following steps: Step 1: Pre-treat and mix H2O, CO2, and H2 to generate a mixed gas; Step 2: After preheating the mixture and air separately, the mixture is supplied to the fuel electrode at the initial total intake flow rate, and the air is supplied to the oxygen electrode. Step 3: Apply an initial current density to the SOEC stack, co-electrolyze to generate syngas, and detect the H2 / CO ratio in the syngas; Step 4: Adjust the H2 / CO ratio.

[0012] Another feature of the technical solution of the present invention is that: Step 1 is as follows: Liquid water is pumped into the steam generator through the first inlet, CO2 is introduced into the steam generator through the second inlet, and H2 is introduced into the steam generator through the third inlet. The liquid water is preheated in the steam generator and converted into superheated steam. The CO2 and H2 gases are mixed with the steam to form a mixed gas.

[0013] Step 2 is as follows: The mixture obtained in step 1 is heated to 750–850°C by the first heater and supplied to the fuel electrode at the initial total intake flow rate. Air is compressed by an air compressor pump, heated to the same temperature as the first heater by a second heater, and then supplied to the oxygen electrode.

[0014] Step 3 specifically includes the following steps: Step 3.1, SOEC stack co-electrolysis, An initial current density is applied in the SOEC stack, and the fuel electrode electrolyzes the supplied mixed gas. The gas is then cooled to 40-80°C by a condenser to remove H2O, and syngas is obtained after water removal. Step 3.2, Syngas Detection, The gas phase detection device detects the H2 / CO ratio in the synthesis gas.

[0015] Step 4 specifically includes the following steps: Step 4.1, coarse adjustment of the H2 / CO ratio. Using the H2 / CO ratio in the syngas measured in step 3 as the initial reference baseline, when it is necessary to increase the H2 content in the produced gas, the H2O ratio is increased in steps of 10% volume fraction, and the total flow rate is increased in steps of 0.1 standard liters per minute (NL / min); when it is necessary to increase the CO content in the produced gas, the H2O ratio is decreased in steps of 10% volume fraction. When the H2 / CO ratio in the produced gas differs from the expected ratio by no more than 10%, step 4.1 ends. Step 4.2, fine-tuning the H2 / CO ratio. By using 0.05 amperes per square centimeter (A / cm²) 2 To adjust the step size, a current density is applied to achieve fine-tuning of the H2 / CO ratio in the synthesis gas.

[0016] In step 1, the volume ratio of H2O / CO2 / H2 is 30~60:30~60:10; in step 2, the initial total inlet flow rate of the mixed gas supplied to the fuel electrode is 0.4 liters per minute per 100 cm². 2 In step 3, the initial current density applied to the SOEC stack is 0.2 A / cm². 2 .

[0017] The beneficial effects of this invention are: (1) The H2 / CO ratio can be precisely adjusted within a wide range (0~10), which is suitable for the different requirements of different downstream reaction processes for the composition of raw materials, such as Fischer-Tropsch synthesis, methanol synthesis, methane synthesis, etc.

[0018] (2) It has flexibility and ease of operation. The composition of the target gas can be quickly adjusted by adjusting the gas ratio and electrolysis parameters without the need for complex process switching.

[0019] (3) It helps to achieve efficient utilization of carbon resources and reduction of greenhouse gas emissions, improve the utilization efficiency of renewable energy, and meet the needs of green manufacturing under the "dual carbon" background. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the process for preparing a wide-ratio synthesis gas according to the present invention; Figure 2 This refers to the H2 / CO ratio of the outlet synthesis gas obtained by testing different inlet component ratios and current densities in embodiments of the present invention. Figure 3 The H2 / CO ratio of the outlet syngas is obtained by testing different fuel electrode flow rates and current densities in embodiments of the present invention.

[0021] In the diagram, 1. First inlet, 2. Second inlet, 3. Third inlet, 4. Water pump, 5. First flow meter, 6. Second flow meter, 7. Steam generator, 8. First heater, 9. Second heater, 10. Air compressor pump, 11. SOEC stack, 1101. Fuel electrode, 1102. Electrolyte, 1103. Oxygen electrode, 12. Condensation and H2O removal device, 13. Gas phase detection device. Detailed Implementation

[0022] The following detailed description is provided in conjunction with specific implementation methods.

[0023] A wide-scale synthesis gas preparation system based on SOEC stack includes a gas supply unit, which is connected to the SOEC unit and the tail gas treatment unit in sequence through pipelines.

[0024] The gas supply unit includes a steam generator 7. One end of the steam generator 7 is connected to a first inlet 1, a second inlet 2, and a third inlet 3 via pipes. The other end of the steam generator 7 is connected to a first heater 8. A water pump 4 is installed between the first inlet 1 and the steam generator 7; a first flow meter 5 is installed between the second inlet 2 and the steam generator 7; and a second flow meter 6 is installed between the third inlet 3 and the steam generator 7.

[0025] The gas supply unit also includes an air compressor pump 10, the output of which is connected to a second heater 9 via a pipe.

[0026] SOEC stack 11 includes several individual cells. Each individual cell includes a fuel electrode 1101, an electrolyte 1102, and an oxygen electrode 1103. A mixture of water vapor, CO2, and H2 passes through a first heater 8 and then flows into the fuel electrode 1101 of each individual cell through a gas pipe. Air passes through a second heater 9 and then flows into the oxygen electrode 1103 of each individual cell through a gas pipe.

[0027] The exhaust gas treatment unit includes a condensation and H2O removal device 12 and a gas phase detection device 13. The inlet of the condensation and H2O removal device 12 is connected to the fuel electrode 1101, and the exhaust gas from the fuel electrode 1101 is input to the condensation and H2O removal device 12. The outlet of the condensation and H2O removal device 12 outputs syngas. The outlet of the condensation and H2O removal device is also connected to the gas phase detection device 13 to detect the syngas. The oxygen electrode 1103 outputs surplus air.

[0028] like Figure 1 As shown, liquid water is pumped into the steam generator 7 via the first inlet 1 and the water pump 4. Simultaneously, CO2 and H2 are introduced into the steam generator 7 via the second inlet 2 and the third inlet 3, respectively. In the steam generator 7, the liquid water is converted into superheated steam, and the CO2 and H2 gases are preheated and thoroughly mixed with the steam to form a stable H2O + CO2 + H2 mixture. This mixture is heated to the operating temperature of the SOEC stack 11 by the first heater 8 and supplied to the fuel electrode 1101 of the SOEC stack 11. The purge air is compressed by the air compressor pump 10, heated to the same temperature by the second heater 9, and supplied to the oxygen electrode 1103 of the SOEC stack 11. A current density is applied to the SOEC stack 11, causing the fuel electrode 1101 of the SOEC stack 11 to electrolyze the supplied H2O and CO2 to generate H2 and CO, which are then fed into the condensation and H2O removal device 12. H2 and CO are cooled and condensed by the H2O removal device 12 to remove moisture, obtaining the target H2 / CO synthesis gas. At the same time, the gas phase detection device 13 detects the H2 / CO ratio in the synthesis gas. The oxygen electrode 1103 of the SOEC stack 11 discharges oxygen-enriched air, which can be recycled or directly discharged.

[0029] The preparation method of a wide-scale syngas preparation system based on SOEC stack is implemented according to the following steps: Step 1: Pre-treat and mix H2O, CO2, and H2 to generate a mixed gas.

[0030] Liquid water is fed into the steam generator 7 through the first inlet 1 and the water pump 4. At the same time, CO2 and H2 are introduced into the steam generator 7 through the second inlet 2 and the third inlet 3, respectively. In the steam generator 7, the liquid water is converted into superheated steam, and the CO2 and H2 gases are preheated and fully mixed with the steam to form a stable H2O + CO2 + H2 mixture.

[0031] The volume ratio of H2O / CO2 / H2 is 30~60:30~60:10. The volume percentage of H2 in the mixture is 10%, which is used to prevent the Ni-based catalyst in the fuel electrode 1101 from being oxidized and deactivated.

[0032] Step 2: After preheating the mixture and air separately, the mixture is supplied to the fuel electrode 1101 at the initial total intake flow rate, and the air is supplied to the oxygen electrode 1103.

[0033] The mixed gas obtained in step 1 is heated to the operating temperature of the SOEC stack 11, which is 750–850°C, by the first heater 8, with an initial total inlet flow rate of 0.4 L / min / 100 cm³. 2 Fuel electrode 1101 is supplied to SOEC stack 11; After being compressed by the air compressor pump 10, the air is heated by the second heater 9 to the same temperature as the first heater 8, and then supplied to the oxygen electrode 1103 of the SOEC stack 11.

[0034] Step 3: Apply an initial current density to the SOEC stack 11, co-electrolyze to generate syngas, and detect the H2 / CO ratio in the syngas.

[0035] Step 3.1, SOEC stack co-electrolysis.

[0036] An initial current density of 0.2 A / cm² was applied to the SOEC stack 11. 2 This causes the fuel electrode 1101 of the SOEC stack 11 to electrolyze the supplied mixed gas to generate H2 and CO. The H2 and CO are cooled to 40~80°C by the condensation and H2O removal device 12. After cooling and condensation to remove moisture, the target H2 / CO synthesis gas is obtained. The oxygen electrode 1103 of the SOEC stack 11 discharges oxygen-enriched air, which can be recycled or directly discharged.

[0037] Step 3.2, Syngas detection.

[0038] The gas phase detection device 13 detects the H2 / CO ratio in the synthesis gas.

[0039] Step 4: Adjust the H2 / CO ratio.

[0040] Step 4.1, coarse adjustment of H2 / CO ratio.

[0041] The H2 / CO ratio in the syngas measured in step 3 is used as the initial reference standard.

[0042] When it is necessary to increase the H2 content in the produced gas, the H2O ratio is increased in steps of 10% by volume, and the total flow rate is increased in steps of 0.1 NL / min; when it is necessary to increase the CO content in the produced gas, the H2O ratio is decreased in steps of 10% by volume.

[0043] When the H2 / CO ratio in the produced gas differs from the expected ratio by no more than 10%, step 4.1 ends, and a preliminary regulation measure is formed.

[0044] Step 4.2, fine-tuning the H2 / CO ratio.

[0045] With the inlet components and total fuel electrode flow rate fixed, by using 0.05 A / cm 2 To fine-tune the applied current density by adjusting the step size, further precise control of the H2 / CO ratio in the synthesis gas can be achieved.

[0046] The above method allows for flexible adjustment of the H2 / CO ratio within the range of 0 to 10:1, meeting the differentiated requirements of various downstream processes (such as Fischer-Tropsch synthesis, methanol synthesis, methanation reaction, etc.) for feedstock composition.

[0047] Example 1 A wide-ratio synthesis gas preparation system based on SOEC stack includes a gas supply unit, which is connected to the SOEC unit and the tail gas treatment unit in sequence through pipelines. The SOEC unit includes an SOEC stack 11, which includes several single cells. Each single cell includes a fuel electrode 1101, an electrolyte 1102 and an oxygen electrode 1103.

[0048] Example 2 A wide-ratio synthesis gas preparation system based on SOEC stack includes a gas supply unit, which is connected to the SOEC unit and the tail gas treatment unit in sequence through pipelines. The SOEC unit includes an SOEC stack 11, which includes several single cells. Each single cell includes a fuel electrode 1101, an electrolyte 1102 and an oxygen electrode 1103.

[0049] The gas supply unit includes a steam generator 7. The inlet end of the steam generator 7 is connected to the first inlet 1, the second inlet 2 and the third inlet 3 respectively through pipes. The outlet end of the steam generator 7 is connected to the first heater 8. A water pump 4 is installed between the first inlet 1 and the steam generator 7; a first flow meter 5 is installed between the second inlet 2 and the steam generator 7; and a second flow meter 6 is installed between the third inlet 3 and the steam generator 7. The gas supply unit also includes an air compressor pump 10, the output of which is connected to a second heater 9 via a pipe.

[0050] Example 3 A wide-ratio synthesis gas preparation system based on SOEC stack includes a gas supply unit, which is connected to the SOEC unit and the tail gas treatment unit in sequence through pipelines. The SOEC unit includes an SOEC stack 11, which includes several single cells. Each single cell includes a fuel electrode 1101, an electrolyte 1102 and an oxygen electrode 1103.

[0051] The gas supply unit includes a steam generator 7. The inlet end of the steam generator 7 is connected to the first inlet 1, the second inlet 2 and the third inlet 3 respectively through pipes. The outlet end of the steam generator 7 is connected to the first heater 8. A water pump 4 is installed between the first inlet 1 and the steam generator 7; a first flow meter 5 is installed between the second inlet 2 and the steam generator 7; and a second flow meter 6 is installed between the third inlet 3 and the steam generator 7. The gas supply unit also includes an air compressor pump 10, the output of which is connected to a second heater 9 via a pipe.

[0052] The first heater 8 is connected to the fuel electrode 1101 via a pipe, and the second heater 9 is connected to the oxygen electrode 1103 via a pipe.

[0053] Example 4 A wide-ratio synthesis gas preparation system based on SOEC stack includes a gas supply unit, which is connected to the SOEC unit and the tail gas treatment unit in sequence through pipelines. The SOEC unit includes an SOEC stack 11, which includes several single cells. Each single cell includes a fuel electrode 1101, an electrolyte 1102 and an oxygen electrode 1103.

[0054] The exhaust gas treatment unit includes a condensation and H2O removal device 12, the inlet of which is connected to a fuel electrode 1101, and the outlet of which outputs syngas; the outlet of the condensation and H2O removal device 12 is also connected to a gas phase detection device 13.

[0055] Example 5 The preparation method of a wide-scale syngas preparation system based on an SOEC stack includes the following steps: Step 1: Pre-treat and mix H2O, CO2, and H2 to generate a mixed gas; Step 2: After preheating the mixture and air separately, the mixture is supplied to the fuel electrode 1101 at the initial total intake flow rate, and the air is supplied to the oxygen electrode 1103. Step 3: Apply an initial current density to the SOEC stack 11, co-electrolyze to generate syngas, and detect the H2 / CO ratio in the syngas; Step 4: Adjust the H2 / CO ratio.

[0056] Example 6 The preparation method of a wide-scale syngas preparation system based on an SOEC stack includes the following steps: Step 1: Pre-treat and mix H2O, CO2, and H2 to generate a mixed gas; Step 2: After preheating the mixture and air separately, the mixture is supplied to the fuel electrode 1101 at the initial total intake flow rate, and the air is supplied to the oxygen electrode 1103. Step 3: Apply an initial current density to the SOEC stack 11, co-electrolyze to generate syngas, and detect the H2 / CO ratio in the syngas; Step 4: Adjust the H2 / CO ratio.

[0057] Step 1 is as follows: Liquid water is fed into steam generator 7 through first inlet 1 and water pump 4. CO2 is fed into steam generator 7 through second inlet 2 and H2 is fed into steam generator 7 through third inlet 3. The liquid water is preheated in steam generator 7 and converted into superheated steam. CO2 and H2 gases are mixed with steam to form a mixed gas.

[0058] Step 2 is as follows: The mixture obtained in step 1 is heated to 750–850°C by the first heater 8 and supplied to the fuel electrode 1101 at the initial total intake flow rate; Air is compressed by air compressor pump 10 and heated to the same temperature as the first heater 8 by second heater 9 before being supplied to oxygen electrode 1103.

[0059] Step 3 specifically involves: Step 3.1, SOEC stack co-electrolysis, An initial current density is applied in the SOEC stack 11, and the fuel electrode 1101 electrolyzes the supplied mixed gas, cools it to 40~80°C through the condenser and H2O removal device 12, and obtains syngas after removing water. Step 3.2, Syngas Detection, The gas phase detection device 13 detects the H2 / CO ratio in the synthesis gas.

[0060] Step 4 specifically includes the following steps: Step 4.1, coarse adjustment of the H2 / CO ratio. Using the H2 / CO ratio in the syngas measured in step 3 as the initial reference baseline, when it is necessary to increase the H2 content in the produced gas, the H2O ratio is increased in steps of 10% volume fraction, and the total flow rate is increased in steps of 0.1 NL / min; when it is necessary to increase the CO content in the produced gas, the H2O ratio is decreased in steps of 10% volume fraction. When the H2 / CO ratio in the produced gas differs from the expected ratio by no more than 10%, step 4.1 ends. Step 4.2, fine-tuning the H2 / CO ratio. By using 0.05A / cm 2To adjust the step size, the current density is applied to achieve fine-tuning of the H2 / CO ratio in the synthesis gas.

[0061] In step 1, the volume ratio of H2O / CO2 / H2 is 30~60:30~60:10; in step 2, the initial total inlet flow rate of the mixed gas supplied to the fuel electrode 1101 is 0.4 L / min / 100 cm³. 2 In step 3, the initial current density applied to the SOEC stack 11 is 0.2 A / cm². 2 .

[0062] Below, we combine 100cm 2 The experimental test results of a single cell further illustrate the actual effectiveness of the present invention.

[0063] Figure 2 The figure shows the variation of the H2 / CO ratio in the syngas obtained under different inlet gas compositions (H2O / CO2 volume percentage), total flow rate of fuel electrodes, and applied current density.

[0064] like Figure 2 As shown, when the battery operating temperature is fixed at 750℃ and the total flow rate of the fuel electrode is 0.4L / min, as the inlet H2O volume percentage gradually increases from 0% to 75% and the current density gradually increases from 0 to 0.4A / cm², 2 The H2 / CO ratio in the syngas outlet can be significantly adjusted within the range of 0–10, meeting the differentiated requirements of various industrial synthesis processes for syngas components.

[0065] The test results show that increasing the inlet H2O volume percentage significantly increases the H2 content in the syngas, while adjusting the current density has a relatively small impact on the H2 / CO ratio. Therefore, the syngas ratio can be coarsely adjusted by regulating the H2O volume fraction, and finely adjusted by regulating the current density applied to the SOEC stack 11.

[0066] like Figure 3 As shown, under the condition of keeping the fuel gas volume fraction fixed at H2O:CO2:H2 = 45:45:10 and the SOEC stack 11 temperature constant, gradually increasing the total flow rate of the fuel electrode gas from 0.4 L / min to 1.0 L / min can significantly improve the H2 / CO ratio in the syngas. Furthermore, the effect of current density on the H2 / CO ratio is flow-dependent: at lower flow rates (0.4 L / min), the H2 / CO ratio gradually decreases with increasing current density; while at higher flow rates (≥0.7 L / min), increasing the current density can slightly increase the H2 / CO ratio.

[0067] Taking Fischer-Tropsch synthesis as an application example, this process typically requires an H2 / CO ratio of 2 in the synthesis gas. Initial operating conditions can be set as follows: total fuel electrode flow rate 0.4 L / min / 100 cm³. 2 The gas mixture ratio is H2O:CO2:H2 = 45:45:10, and the current density is 0.2 A / cm². At this point, the H2 / CO ratio of the resulting syngas is slightly less than 2. To meet the requirements, the inlet H2O volume percentage can be adjusted to 50%, i.e., H2O:CO2:H2 = 50:40:10, and the current density can be fine-tuned to 0.26 A / cm². This will achieve the target H2 / CO ratio of 2 in the syngas production, satisfying the feedstock requirements for Fischer-Tropsch synthesis.

Claims

1. A wide-ratio synthesis gas preparation system based on an SOEC fuel cell stack, characterized in that, It includes a gas supply unit, which is connected to the SOEC unit and the exhaust gas treatment unit in sequence through pipelines; the SOEC unit includes an SOEC stack (11), which includes several single cells, each single cell including a fuel electrode (1101), an electrolyte (1102) and an oxygen electrode (1103).

2. The SOEC-based wide-ratio synthesis gas preparation system according to claim 1, characterized in that, The gas supply unit includes a steam generator (7), the inlet of which is connected to the first inlet (1), the second inlet (2) and the third inlet (3) respectively via pipes, and the outlet of the steam generator (7) is connected to the first heater (8). A water pump (4) is installed between the first inlet (1) and the steam generator (7), a first flow meter (5) is installed between the second inlet (2) and the steam generator (7), and a second flow meter (6) is installed between the third inlet (3) and the steam generator (7). The gas supply unit also includes an air compressor pump (10), the output of which is connected to a second heater (9) via a pipe.

3. The SOEC-based wide-ratio synthesis gas preparation system according to claim 2, characterized in that, The first heater (8) is connected to the fuel electrode (1101) via a pipe, and the second heater (9) is connected to the oxygen electrode (1103) via a pipe.

4. The wide-ratio synthesis gas preparation system based on an SOEC stack according to claim 1, characterized in that, The exhaust gas treatment unit includes a condensation H2O removal device (12), the inlet of which is connected to a fuel electrode (1101), and the outlet of which outputs syngas; the outlet of which is also connected to a gas phase detection device (13).

5. A method for preparing a wide-scale syngas preparation system based on an SOEC fuel cell stack, characterized in that, The wide-ratio synthesis gas preparation system based on SOEC stacks as described in claims 1-4 specifically includes the following steps: Step 1: Pre-treat and mix H2O, CO2, and H2 to generate a mixed gas; Step 2: After preheating the mixture and air separately, the mixture is supplied to the fuel electrode (1101) at the initial total intake flow rate, and the air is supplied to the oxygen electrode (1103). Step 3: Apply an initial current density to the SOEC stack (11), co-electrolyze to generate syngas, and detect the H2 / CO ratio in the syngas; Step 4: Adjust the H2 / CO ratio.

6. The method for preparing a wide-scale syngas preparation system based on an SOEC stack according to claim 5, characterized in that, Step 1 specifically involves: Liquid water is fed into the steam generator (7) through the first inlet (1) and the water pump (4). CO2 is fed into the steam generator (7) through the second inlet (2) and H2 is fed into the steam generator (7) through the third inlet (3). The liquid water is preheated in the steam generator (7) and converted into superheated steam. CO2 and H2 gases are mixed with the steam to form a mixed gas.

7. The method for preparing a wide-scale syngas preparation system based on an SOEC stack according to claim 5, characterized in that, Step 2 specifically involves: The mixture obtained in step 1 is heated to 750–850°C by the first heater (8) and supplied to the fuel electrode (1101) at the initial total intake flow rate. Air is compressed by an air compressor pump (10) and then heated by a second heater (9) to the same temperature as the first heater (8) before being supplied to the oxygen electrode (1103).

8. The method for preparing a wide-scale syngas preparation system based on an SOEC stack according to claim 5, characterized in that, Step 3 specifically includes the following steps: Step 3.1, SOEC stack co-electrolysis, An initial current density is applied in the SOEC stack (11), and the fuel electrode (1101) electrolyzes the supplied mixed gas, cools it to 40~80°C through a condenser and H2O removal device (12), and obtains syngas after removing water; Step 3.2, Syngas Detection, The gas phase detection device (13) detects the H2 / CO ratio in the synthesis gas.

9. The method for preparing a wide-scale syngas preparation system based on an SOEC stack according to claim 5, characterized in that, Step 4 specifically includes the following steps: Step 4.1, coarse adjustment of the H2 / CO ratio. Using the H2 / CO ratio in the syngas measured in step 3 as the initial reference baseline, when it is necessary to increase the H2 content in the produced gas, the H2O ratio is increased in steps of 10% volume fraction, and the total flow rate is increased in steps of 0.1 NL / min; when it is necessary to increase the CO content in the produced gas, the H2O ratio is decreased in steps of 10% volume fraction. When the H2 / CO ratio in the produced gas differs from the expected ratio by no more than 10%, step 4.1 ends. Step 4.2, fine-tuning the H2 / CO ratio. By using 0.05A / cm 2 To adjust the step size, the current density is applied to achieve fine-tuning of the H2 / CO ratio in the synthesis gas.

10. The method for preparing a wide-scale syngas preparation system based on an SOEC stack according to claim 5, characterized in that, In step 1, the volume ratio of H2O / CO2 / H2 is 30~60:30~60:10; in step 2, the initial total inlet flow rate of the mixed gas supplied to the fuel electrode (1101) is 0.4 L / min / 100 cm³. 2 In step 3, the initial current density applied to the SOEC stack (11) is 0.2 A / cm. 2 .

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