Method and device for preparing synthesis gas through high-temperature electrolysis

Abstract

The invention discloses a method and device for preparing synthesis gas through high-temperature electrolysis, and the method comprises the following steps: raw material gas enters an electrolytic tank from an anode inlet, and anode tail gas directly enters a cathode of the electrolytic tank and finally leaves the electrolytic tank from a cathode outlet; the raw material gas comprises hydrocarbon fuel, water vapor and / or carbon dioxide, and the hydrocarbon fuel comprises methane, ethane, propane, methanol, ethanol and / or biomass gasified gas; the water vapor and / or carbon dioxide in the raw material gas are / is subjected to an electrolytic reduction reaction at the cathode to generate hydrogen and / or carbon monoxide, and the hydrocarbon fuel in the raw material gas is subjected to a partial oxidation reaction at the anode to generate hydrogen and carbon monoxide. The device has the advantages that the gas inlet and outlet path design and gas inlet component management of the device for preparing the synthesis gas through electrolysis of the hydrocarbon fuel assisted solid oxide are simplified, the carbon deposition resistance of the anode is enhanced, and the stability and the reliability of operation of the device are improved.

Description

Technical Field

[0001] The present invention relates to a method and device for preparing synthesis gas, and in particular to a method and device for preparing synthesis gas by high-temperature electrolysis. Background Art

[0002] Synthesis gas is a mixed gas with H2 and CO as the main components. It is an important raw material or intermediate in the petrochemical industry and is widely used in the synthesis of bulk chemical products such as ammonia, olefins, and methanol. Coal gasification and natural gas conversion are the two main methods for producing synthesis gas in the traditional chemical route. The former uses oxygen, water vapor, etc. as gasification agents to convert the combustible components in coal or coke into gas at high temperature. Its effective components include CO, H2, CO2, CH4, etc.; the latter is based on steam reforming, carbon dioxide reforming, partial oxidation reforming, or the coupling of the above reforming methods to convert natural gas into synthesis gas with different H2 / CO molar ratios. These thermochemical process technologies are mature and have strong production capacity, but they consume a large amount of non-renewable fossil energy and need to be carried out under harsh conditions such as high temperature and high pressure, which leads to problems such as high energy consumption, waste of resources, and environmental pollution.

[0003] Solid oxide electrolysis cell (SOEC) is an all-solid-state electrochemical device based on a ceramic electrolyte diaphragm. Its operating temperature is generally 400-1000°C. It can use renewable electricity to electrolyze H2O into H2 and O2, or electrolyze CO2 into CO and O2, thereby converting surplus electrical energy into fuel chemical energy. SOEC can also simultaneously electrolyze H2O / CO2 to generate syngas and O2, becoming one of the important emerging alternative technologies for the sustainable preparation of syngas.

[0004] In the prior art, Energy&Fuels 2009,23,3089–3096 adopts a traditional flat-plate SOEC, CN116200755A adopts a hollow flat tube SOEC, and CN103613066A adopts a micro-tube SOEC, where H2O / CO2 are co-electrolyzed into synthesis gas at the cathode, and O2 is simultaneously produced at the anode; International Journal of Hydrogen Energy 2021,46,20305-20312 introduces CH4 fuel into the anode of SOEC, CN107180985A introduces low-concentration coalbed methane containing gases such as CH4, N2 and CO2 into the anode of SOEC, and CN107868962A introduces a mixture of carbon powder, catalyst and molten salt into the anode of SOEC, so that the oxygen ions produced by co-electrolysis and transmitted to the anode side can react with hydrocarbon fuels or solid carbon on the anode side to generate synthesis gas or carbon monoxide, thereby reducing the energy consumption of the electrolysis process.

[0005] However, these hydrocarbon fuel or solid carbon fuel assisted SOEC electrolysis technologies have the following problems in practical applications: first, the input and output gases of the cathode and anode are independent of each other, which is a complex structural design of "two inlets and two outlets"; second, the high-purity or high-concentration hydrocarbon fuel (such as CH4) input at the anode inlet is prone to cracking and carbon deposition reactions at high temperatures, resulting in anode structural damage and performance degradation, or even complete failure; third, when inputting H2O and / or CO2 at the cathode inlet, it is often necessary to simultaneously input a certain amount of H2 or CO as a safety gas to prevent the cathode from failing due to oxidation reactions (such as Ni being oxidized to NiO) in high-concentration H2O / CO2. Summary of the invention

[0006] Purpose of the invention: The present invention aims to provide a method and device for preparing synthesis gas by high-temperature electrolysis of SOEC with "one inlet and one outlet", which solves the problems of complex inlet and outlet gas path design, gas composition management, anode carbon deposition, etc. faced by hydrocarbon fuel-assisted solid oxide electrolysis cells. Technical solution: The present invention provides a method for preparing synthesis gas by solid oxide electrolysis cell, which comprises: raw gas enters the electrolysis cell from the anode inlet, anode tail gas directly enters the cathode of the electrolysis cell, and finally leaves the electrolysis cell from the cathode outlet; the raw gas comprises hydrocarbon fuel, water vapor and / or carbon dioxide, and the hydrocarbon fuel includes but is not limited to methane, ethane, propane, methanol, ethanol, biomass gasification gas, etc.; the water vapor and / or carbon dioxide in the raw gas undergo electrolytic reduction reaction at the cathode to generate hydrogen and / or carbon monoxide, and the hydrocarbon fuel in the raw gas undergoes partial oxidation reaction at the anode to generate hydrogen and carbon monoxide.

[0007] The solid oxide electrolysis stack for preparing synthesis gas by high-temperature electrolysis of the present invention comprises an anode end plate, an intermediate plate assembly and a cathode end plate. The intermediate plate assembly comprises a plurality of repeating units, and each repeating unit is connected by a connecting plate.

[0008] The repeating unit includes an anode seal, an anode current collector, an electrolytic cell, a cathode current collector, a middle frame and a cathode seal which are packaged in sequence, wherein the anode seal, the middle frame and the cathode seal are all hollow frames, and the seal seals the electrolytic cell, the current collector and the middle frame on the connecting plate;

[0009] The anode end plate, the repeating unit and the connecting plate are each provided with at least one air inlet and one air outlet on one side, the other side of the repeating unit is provided with at least one opening, and the cathode end plate is not provided with an opening;

[0010] In the electrolytic cell, the raw gas enters the electrolytic cell from the inlet of the anode, the tail gas of the anode directly enters the cathode of the electrolytic cell, and finally leaves the electrolytic cell from the outlet of the cathode. The raw gas is composed of hydrocarbon fuel, water vapor, carbon dioxide, etc., and the hydrocarbon fuel includes but is not limited to methane, ethane, propane, methanol, ethanol, biomass gasification gas, etc. The hydrocarbon fuel in the raw gas undergoes a partial oxidation reaction at the anode to generate synthesis gas, and the water vapor and / or carbon dioxide in the raw gas undergo an electrolytic reduction reaction at the cathode to generate hydrogen and / or carbon monoxide.

[0011] Furthermore, the electrolytic cell comprises a cathode, an anode and an electrolyte, and the cathode, the electrolyte and the anode are processed by high temperature sintering and other processes to form a close interface bonding.

[0012] Furthermore, the electrolyte is a ceramic material with oxygen ion conductivity, including but not limited to yttria-stabilized zirconia, scandia-stabilized zirconia, doped cerium oxide, strontium magnesium-doped lanthanum gallate, doped barium zirconate, doped barium ceria, and the like.

[0013] Furthermore, both the cathode and the anode are composite ceramics composed of an electronic conductive phase and an oxygen ion conductive phase, and the volume fraction of the electronic conductive phase in the solid phase is not less than 40%.

[0014] Furthermore, the electronic conductive phase in the cathode and the anode is a metal, an alloy, a conductive ceramic or a composite thereof, including but not limited to Ni, Cu, 430L, (La 1-x Sr x )(Cr 1-y Fe y ) 3-δ , (La 1-x Sr x )(Cr 1-y Mn y ) 3-δ ,La 2- x Sr x Fe 2-y-z Ni y Mo z O 6-δ 、430L-(La 1-x Sr x )(Cr 1-y Fe y ) 3-δ wait.

[0015] Furthermore, the oxygen ion conductive phase in the cathode and the anode is an oxide having oxygen ion conductivity, including but not limited to yttria-stabilized zirconia, scandia-stabilized zirconia, doped cerium oxide, strontium magnesium-doped lanthanum gallate, doped barium zirconate, doped barium ceria, etc.

[0016] Furthermore, the electrolyte is dense, with a thickness ranging from 1 to 1000 microns, preferably ranging from 10 to 30 microns.

[0017] Furthermore, the cathode and the anode are both porous, with a porosity ranging from 5% to 95%, preferably ranging from 30% to 50%.

[0018] Furthermore, the thickness of the cathode and the anode is in the range of 0.05-1.5 mm, preferably in the range of 0.1-0.5 mm.

[0019] Furthermore, the chemical composition, porosity and thickness of the cathode and the anode may be the same or different.

[0020] Furthermore, the operating temperature of the solid oxide electrolytic cell is in the range of 400-1000°C, preferably in the range of 500-750°C.

[0021] Furthermore, the operating voltage between the cathode and the anode of the solid oxide electrolytic cell is 0.1-2.0V, preferably in the range of 0.3-1.3V.

[0022] Preferably, the inner wall of the cathode hole is covered with nano catalyst materials, including but not limited to Ni, Fe, Co, FeNi3, Ce 1-x Sm x O 2-δ 、Ce 1-x G x O 2-δ , (La 1-x Sr x )(Co 1-y Fe y ) 3-δ 、(Ba 1-x Sr x )(Co 1-y Fe y ) 3-δ 、(Sm 1- x Sr x )CoO 3-δ 、SmBaCo2O 5+δ 、LaBa 0.5 Sr 0.5 Co2O 5+δ 、SmBa 0.5 Sr 0.5 Co2O 5+δ ,BaGd 0.8 La 0.2 Co2O 6-δ ,La 2- x Srx Fe 2-y-z Ni y Mo z O 6-δ wait.

[0023] Preferably, the inner wall of the anode hole is covered with nano catalyst materials, including but not limited to Ni, Fe, Co, FeNi3, Ce 1-x Sm x O 2-δ 、Ce 1-x G x O 2-δ , (La 1-x Sr x )(Co 1-y Fe y ) 3-δ 、(Ba 1-x Sr x )(Co 1-y Fe y ) 3-δ 、(Sm 1- x Sr x )CoO 3-δ 、SmBaCo2O 5+δ 、LaBa 0.5 Sr 0.5 Co2O 5+δ 、SmBa 0.5 Sr 0.5 Co2O 5+δ ,BaGd 0.8 La 0.2 Co2O 6-δ ,La 2- x Sr x Fe 2-y-z Ni y Mo z O 6-δ wait.

[0024] Further, the anode end plate is the top surface of the electrolytic stack, and the cathode end plate is the bottom surface of the electrolytic stack. The anode seal, anode current collector, middle frame, electrolytic cell, cathode seal, cathode current collector and connecting plate constitute a repeating unit of the electrolytic stack.

[0025] Furthermore, the anode seal, the middle frame, and the cathode seal are all hollow frames, and the seal seals the electrolytic cell and the middle frame to the connecting plate. The top surface of the middle frame is sealed with the bottom surface of the connecting plate or the bottom surface of the anode end plate in the adjacent repeating unit through the anode seal to form an anode chamber; the bottom surface of the middle frame is sealed with the top surface of the connecting plate or the top surface of the cathode end plate through the cathode seal to form a cathode chamber.

[0026] Further, the anode current collector is filled in the anode chamber, the top surface of the anode current collector is in close contact with the bottom surface of the connecting plate in the adjacent repeating unit or the bottom surface of the anode end plate, and the bottom surface of the anode current collector is in close contact with the anode of the electrolytic cell; the cathode current collector is filled in the cathode chamber, the top surface of the cathode current collector is in close contact with the cathode of the electrolytic cell, and the bottom surface of the cathode current collector is in close contact with the top surface of the connecting plate or the top surface of the cathode end plate.

[0027] Furthermore, the right side of the anode end plate is provided with a raw gas inlet and a product gas outlet of the electrolytic stack; the right sides of the anode seal, the middle frame, the cathode seal and the connecting plate are provided with suitable openings to ensure that the anode chambers in different repeating units are connected to the raw gas inlet, and the cathode chambers in different repeating units are connected to the product gas outlet.

[0028] Furthermore, suitable openings are provided on the left side of the middle frame, the middle frame seal and the middle frame bottom plate to ensure that the anode chamber and the cathode chamber of the electrolytic cell are connected, so that the tail gas of the anode can directly enter the cathode chamber of the electrolytic cell.

[0029] Furthermore, the anode end plate, the anode seal, the middle frame, the cathode seal, the connecting plate and the cathode end plate are all dense.

[0030] Furthermore, the anode end plate, the middle frame, the connecting plate and the cathode end plate are high temperature alloys or conductive oxides having a thermal expansion coefficient close to that of the electrolyte, including but not limited to 430L, 441, 446, Crofer, (La 1-x Sr x )TiO 3–δ ,La 2-x Sr x Fe 2-y-z Ni y Mo z O 6-δ wait.

[0031] Furthermore, the surfaces of the anode end plate, the connecting plate and the cathode end plate are covered with a conductive protective coating, including but not limited to Ni, Fe, Co, FeNi3, (La1-x Sr x )(Cr 1-y Fe y ) 3–δ , (La 1-x Sr x )(Cr 1-y Mn y ) 3–δ , (La 1-x Sr x )TiO 3–δ ,La 2-x Sr x Fe 2-y-z Ni y Mo z O 6-δ wait.

[0032] Furthermore, the anode current collector and the cathode current collector are metals, alloys, conductive oxides or composites thereof with high porosity and good electronic conductivity, including but not limited to nickel foam, nickel felt, nickel mesh, copper foam, copper felt, copper mesh, stainless steel mesh, porous (La 1-x Sr x )TiO 3–δ 、Porous La 2-x Sr x Fe 2-y-z Ni y Mo z O 6-δ wait.

[0033] Furthermore, the anode seal and the cathode seal are high-temperature sealing materials with high resistivity, including but not limited to glass, mica or vermiculite.

[0034] Furthermore, the present invention provides a device for preparing synthesis gas by high-temperature and high-pressure electrolysis, comprising a high-pressure container and the above-mentioned solid oxide electrolysis stack for preparing synthesis gas by high-temperature electrolysis, wherein the solid oxide electrolysis stack for preparing synthesis gas by high-temperature electrolysis is placed in the cavity of the high-pressure container, and the cavity of the high-pressure container is connected to the cathode chamber and the anode chamber of the solid oxide electrolysis stack.

[0035] Furthermore, the present invention provides a hydrocarbon fuel synthesis equipment, including the high-temperature and high-pressure electrolysis synthesis gas preparation device, a fuel high-pressure synthesis module, a thermal management module and an intelligent control module, etc. The high-pressure synthesis gas generated by the high-temperature and high-pressure electrolysis synthesis gas preparation device directly enters the fuel high-pressure synthesis module and is converted into hydrocarbon fuel; the thermal management module is composed of one or more components of a steam generator, a heat exchanger, and an electric heater, which are used to preheat the raw gas and recover the waste heat of the process gas and the product gas; the hydrocarbon fuel includes but is not limited to methanol, ethanol, gasoline, diesel, sustainable aviation kerosene, etc.

[0036] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) It simplifies the design of the inlet and outlet gas paths and the management of the inlet composition of the hydrocarbon fuel-assisted solid oxide electrolysis stack to produce synthesis gas, realizes "one inlet and one outlet", enhances the anode's anti-carbon deposition performance, and improves the stability and reliability of the device operation; (2) Since the cavity of the high-pressure container is connected to the cathode chamber and the anode chamber, not only can the high-pressure operation of the SOEC be realized, but it can also be directly connected to the fuel high-pressure synthesis module for operation, simplifying the system design and improving the system energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the principle of producing synthesis gas by the device of the present invention;

[0038] Figure 2 It is a schematic diagram of the packaging structure of the device of the present invention;

[0039] Figure 3 Schematic diagram of the packaging structure of the electrolytic stack repeating unit. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0041] Figure 1-3 The reference numerals in the figures are as follows:

[0042] Label name Label name 100 Electrolytic Cell 8 Anode terminal plate 1 anode 9 Anode seal 2 Electrolytes 10 Anode current collector 3 cathode 11 Middle frame 4 Electronically conductive phase 12 Cathode seal 5 Oxygen ion conducting phase 13 Cathode current collector 6 Anode Nanocatalyst Materials 14 Connecting plate 7 Cathode Nanocatalyst Materials 15 Cathode terminal plate 200 Raw gas 16 Anode chamber 300 Product gas 17 Cathode chamber 400 Electrolytic stack 18 Raw gas inlet 500 Repeating Unit 19 Product gas outlet

[0043] Example 1

[0044] like Figure 2 As shown, the solid oxide electrolytic stack 400 includes an anode end plate 8, an anode seal 9, an anode current collector 10, an electrolytic cell 100, a middle frame 11, a cathode current collector 13, a cathode seal 12, a connecting plate 14 and a cathode end plate 15.

[0045] The electrolytic cell 100 includes an anode 1, an electrolyte 2 and a cathode 3 sintered from top to bottom ( Figure 1 ). The raw gas 200 enters the electrolytic cell 100 from the inlet of the anode 1 , the tail gas of the anode 1 directly enters the cathode 3 of the electrolytic cell 100 , and the product gas 300 of the cathode 3 leaves the electrolytic cell 100 from the outlet of the cathode 3 .

[0046] The anode terminal plate 8 is the top surface of the electrolytic stack 400, the cathode terminal plate 15 is the bottom surface of the electrolytic stack 400, and no opening is provided on the cathode terminal plate 15. The anode seal 9, the anode current collector 10, the electrolytic cell 100, the cathode seal 12, the middle frame 11 and the cathode current collector 13 constitute a repeating unit 500 of the electrolytic stack 400 ( Figure 3 ), each repeating unit 500 is connected by a connecting plate 14.

[0047] The anode seal 9 , the middle frame 11 and the cathode seal 12 are all hollow frames, and the seals seal the electrolytic cell 100 and the middle frame 11 onto the connecting plate 14 .

[0048] The top surface of the middle frame 11 is sealed together with the bottom surface of the connecting plate 14 or the bottom surface of the anode end plate 8 in the adjacent repeating unit 500 through the anode seal 9, and forms an anode chamber 16; the bottom surface of the middle frame 11 is sealed together with the top surface of the connecting plate 14 or the top surface of the cathode end plate 15 through the cathode seal 12, and forms a cathode chamber 17.

[0049] The anode current collector 10 is filled in the anode chamber 16, and the top surface of the anode current collector 10 is in close contact with the bottom surface of the connecting plate 14 in the adjacent repeating unit 500 or the bottom surface of the anode end plate 8, and the bottom surface of the anode current collector 10 is in close contact with the anode 1 of the electrolytic cell 100; the cathode current collector 13 is filled in the cathode chamber 17, and the top surface of the cathode current collector 13 is in close contact with the cathode 3 of the electrolytic cell 100, and the bottom surface of the cathode current collector 13 is in close contact with the top surface of the connecting plate 14 or the top surface of the cathode end plate 15.

[0050] like Figure 2 As shown, the raw gas inlet 18 and the product gas outlet 19 of the electrolytic stack 400 are provided on the right side of the anode end plate 8; suitable openings are provided on the right sides of the anode seal 9, the middle frame 11, the cathode seal 12, and the connecting plate 14 to ensure that the anode chamber 16 in different repeating units 500 is connected to the raw gas inlet 18, and the cathode chamber 17 in different repeating units 500 is connected to the product gas outlet 19.

[0051] A suitable opening is provided on the left side of the middle frame 11 to ensure that the anode chamber 16 and the cathode chamber 17 of the electrolytic cell 100 are connected, so that the tail gas of the anode 1 can directly enter the cathode chamber 17 of the electrolytic cell 100 .

[0052] The anode end plate 8, the anode seal 9, the middle frame 11, the cathode seal 12, the connecting plate 14 and the cathode end plate 5 are all dense.

[0053] The anode terminal plate 8, the anode current collector 10, the anode 1 and cathode 3 of the electrolytic cell 100, the cathode current collector 13, the connecting plate 14 and the cathode terminal plate 15 all have high electronic conductivity, and the electrolyte 2 of the electrolytic cell 100 has high oxygen ion conductivity. The close interface contact between adjacent components will minimize the interface contact resistance and promote the rapid transmission of electrons. The anode current collector 10 and the cathode current collector 13 both have high porosity, which will promote the rapid transmission and uniform distribution of gas in the anode chamber 18 and the cathode chamber 19, respectively, thereby increasing the electrode reaction rate.

[0054] Both the anode seal 9 and the cathode seal 12 have high electrical resistance, which prevents short circuit problems between the anode 1 and the cathode 3 of the electrolytic cell 100 and also prevents short circuit problems between adjacent repeating units 500 .

[0055] Anode end plate 8, middle frame 11, connection plate 14 and cathode end plate 15 are high temperature alloy 446 having a thermal expansion coefficient close to that of electrolyte 2 of electrolytic cell 100. The surfaces of anode end plate 8, connection plate 14 and cathode end plate 15 are covered with conductive protective coating FeNi3 alloy.

[0056] The anode current collector 10 and the cathode current collector 13 are nickel foam metals having high porosity and good electronic conductivity.

[0057] The anode seal 9 and the cathode seal 13 are high temperature sealing glasses with high resistivity.

[0058] The inner wall of the hole of the anode 1 is covered with an anode nano-catalyst material 6, and the nano-catalyst material 6 is Ce 0.8 G 0.2 The inner wall of the pores of the cathode 3 is covered with a nano catalyst material 7, which is La 0.5 Sr 1.5 Fe 1.5 Ni 0.1 Mo 0.4 O6.

[0059] Example 2

[0060] Based on the device described in Example 1, raw gas 200 is introduced at the raw gas inlet 18. The raw gas 200 is composed of CH4, H2O and CO2, and the volume ratio of the three gases is CH4:H2O:CO2=3:2:1. A voltage of 0.5V is applied between the anode 1 and the cathode 3.

[0061] When the raw gas 200 passes through the anode 1, CH4 is electrolyzed with the cathode and O is transferred through the electrolyte 2. 2- Reacts to generate H2 and CO, and the anode reaction is

[0062] After the anode tail gas enters the cathode 3, the H2O and CO2 in the mixed gas will undergo a co-electrolysis reaction, and the cathode reaction is 2H2O+CO2+6e - →2H2+CO+3O 2- .

[0063] The overall reaction of the electrolytic cell 100 is 3CH4+2H2O+CO2→8H2+4CO. It can be seen that the product gas 300 of the cathode 3 is synthesis gas, and the volume ratio of H2 to CO is 2. The product gas is collected at the product gas outlet 19.

[0064] Example 3

[0065] Based on the device described in Example 1, raw gas 200 is introduced at the raw gas inlet 18. The raw gas 200 is composed of ethanol and water vapor, and the volume ratio of the two gases is C2H6O:H2O=1:1. The voltage applied between the anode 1 and the cathode 3 is 0.4V.

[0066] When the raw gas 200 passes through the anode 1, C2H6O is electrolyzed with the cathode and O is transferred through the electrolyte 2. 2- Reacts to generate H2 and CO, and the anode reaction is

[0067] After the anode tail gas enters the cathode 3, the H2O in the mixed gas will undergo an electrolysis reaction, and the cathode reaction is H2O+2e - →H2+O 2- .

[0068] The overall reaction of the electrolytic cell 100 is C2H6O+H2O→4H2+2CO. It can be seen that the product gas 300 of the cathode 3 is synthesis gas, and the volume ratio of H2 to CO is 2. The product gas is collected at the product gas outlet 19.

[0069] Example 4

[0070] Based on the device described in Example 1, raw gas 200 is introduced at the raw gas inlet 18. The raw gas 200 is composed of CH4 and CO2, and the volume ratio of the two gases is CH4:CO2=1:1. The voltage applied between the anode 1 and the cathode 3 is 0.8V.

[0071] When the raw gas 200 passes through the anode 1, CH4 is electrolyzed with the cathode and O is transferred through the electrolyte 2. 2- Reacts to generate H2 and CO, and the anode reaction is

[0072] After the anode tail gas enters the cathode 3, the CO2 in the mixed gas will undergo an electrolysis reaction, and the cathode reaction is CO2+2e - →CO+O2- .

[0073] The overall reaction of the electrolytic cell 100 is CH4+CO2→2H2+2CO. It can be seen that the product gas 300 of the cathode 3 is synthesis gas, and the volume ratio of H2 to CO is 1. The product gas is collected from the product gas outlet 19.

Claims

1. A method for preparing synthesis gas by high temperature electrolysis, characterized in that: The method comprises: raw gas enters an electrolytic cell from an anode inlet, anode tail gas directly enters a cathode of the electrolytic cell, and finally leaves the electrolytic cell from a cathode outlet; the raw gas comprises hydrocarbon fuel, water vapor and / or carbon dioxide, and the hydrocarbon fuel comprises methane, ethane, propane, methanol, ethanol and / or biomass gasification gas; the water vapor and / or carbon dioxide in the raw gas undergo an electrolytic reduction reaction at the cathode to generate hydrogen and / or carbon monoxide, and the hydrocarbon fuel in the raw gas undergoes a partial oxidation reaction at the anode to generate hydrogen and carbon monoxide.

2. A solid oxide electrolysis stack for preparing synthesis gas by high temperature electrolysis based on the method of claim 1, characterized in that: It comprises an anode end plate (8), an intermediate plate assembly and a cathode end plate (15), wherein the intermediate plate assembly comprises a plurality of repeating units, and each of the repeating units is connected by a connecting plate (14); The repeating unit comprises an anode seal (9), an anode current collector (10), an electrolytic cell (100), a cathode current collector (13), a middle frame (11) and a cathode seal (12) which are packaged in sequence, wherein the anode seal (9), the middle frame (11) and the cathode seal middle frame (12) are all hollow frames, and the seal seals the electrolytic cell, the current collector and the middle frame (11) on a connecting plate (14); The anode end plate (8), the repeating unit and the connecting plate (14) are each provided with at least one air inlet and one air outlet on the same side, and the other side of the repeating unit is provided with at least one opening; In the electrolytic cell (100), the raw gas enters the electrolytic cell from the inlet of the anode (1), the tail gas of the anode directly enters the cathode (3) of the electrolytic cell, and finally leaves the electrolytic cell from the outlet of the cathode (3).

3. The solid oxide electrolysis stack for preparing synthesis gas by high temperature electrolysis according to claim 2, characterized in that: The anode seal (9), the middle frame (11), the cathode seal (12) and the connecting plate (14) are provided with suitable openings on the same side to ensure that the anode chambers (16) in different repeating units are connected to the raw gas inlet, and the cathode chambers (17) in different repeating units are connected to the product gas outlet; the other side of the anode seal (9), the middle frame (11) and the cathode seal (12) are provided with suitable openings to ensure that the anode chamber (16) of the electrolytic cell (100) is connected to the cathode chamber (17), so that the tail gas of the anode chamber (16) can directly enter the cathode chamber (17).

4. The solid oxide electrolysis stack for preparing synthesis gas by high temperature electrolysis according to claim 2, characterized in that: The anode current collector (10) is filled in the anode chamber (16), the top surface of the anode current collector (10) is in close contact with the bottom surface of the connecting plate (14) or the bottom surface of the anode end plate (8) in the adjacent repeating unit, and the bottom surface of the anode current collector (10) is in close contact with the anode (1) of the electrolytic cell (100); the cathode current collector (13) is filled in the cathode chamber (17), the top surface of the cathode current collector (13) is in close contact with the cathode (3) of the electrolytic cell (100), and the bottom surface of the cathode current collector (13) is in close contact with the top surface of the connecting plate (14) or the top surface of the cathode end plate (15).

5. The solid oxide electrolysis stack for preparing synthesis gas by high temperature electrolysis according to claim 2, characterized in that: The material of the anode end plate (8), the middle frame (11), the connecting plate (14) and the cathode end plate (15) is a high-temperature alloy or a conductive oxide having a thermal expansion coefficient close to that of the electrolyte, selected from 430L, 441, 446, Crofer, (La 1-x Sr x )TiO 3–δ or La 2-x Sr x Fe 2-y- z Ni y Mo z O 6-δ At least one of the above, the anode current collector (10) and the cathode current collector (13) are made of metals, alloys, conductive oxides or composites thereof with high porosity and good electronic conductivity, selected from foamed nickel, nickel felt, nickel mesh, foamed copper, copper felt, copper mesh, stainless steel mesh, porous (La 1-x Sr x )TiO 3–δ or porous La 2-x Sr x Fe 2-y-z Ni y Mo z O 6-δ At least one of the above, the surfaces of the anode end plate (8), the connecting plate (14) and the cathode end plate (15) are covered with a conductive protective coating, and the conductive protective coating is selected from Ni, Fe, Co, FeNi3, (La 1-x Sr x )(Cr 1-y Fe y ) 3–δ , (La 1-x Sr x )(Cr 1-y Mn y ) 3–δ , (La 1-x Sr x )TiO 3–δ or La 2-x Sr x Fe 2-y-z Ni y Mo z O 6-δ At least one of the anode seal (9) and the cathode seal (12) is made of a high-temperature sealing material with high resistivity, selected from glass, mica or vermiculite.

6. The solid oxide electrolysis stack for preparing synthesis gas by high temperature electrolysis according to claim 2, characterized in that: The raw gas includes at least two of hydrocarbon fuel, water vapor and carbon dioxide, and the hydrocarbon fuel includes at least one of methane, ethane, propane, methanol, ethanol or biomass gasification gas.

7. The solid oxide electrolysis stack for preparing synthesis gas by high temperature electrolysis according to claim 2, characterized in that: The electrolyte (2) is selected from at least one of yttria-stabilized zirconia, scandium-stabilized zirconia, doped cerium oxide, strontium magnesium-doped lanthanum gallate, doped barium zirconate or doped barium ceria; the cathode (3) and the anode (1) are both composite ceramics including an electronic conductive phase and an oxygen ion conductive phase, wherein the volume fraction of the electronic conductive phase in the solid phase is not less than 40%; the electronic conductive phase (4) is a metal, an alloy, a conductive ceramic or a composite thereof, selected from Ni, Cu, 430L, (La 1-x Sr x )(Cr 1-y Fe y ) 3-δ , (La 1-x Sr x )(Cr 1-y Mn y ) 3-δ ,La 2-x Sr x Fe 2-y-z Ni y Mo z O 6-δ or 430L-(La 1-x Sr x )(Cr 1-y Fe y ) 3-δ At least one of the above, the oxygen ion conductive phase (5) is an oxide having oxygen ion conductivity, selected from at least one of yttria-stabilized zirconia, scandium oxide-stabilized zirconia, doped cerium oxide, strontium magnesium-doped lanthanum gallate, doped barium zirconate or doped barium cerate; the inner wall of the pores of the cathode (3) is covered with a nano catalyst material, selected from Ni, Fe, Co, FeNi3, Ce, 1-x Sm x O 2-δ 、Ce 1- x G x O 2-δ , (La 1-x Sr x )(Co 1-y Fe y ) 3-δ 、(Ba 1-x Sr x )(Co 1-y Fe y ) 3-δ 、(Sm 1-x Sr x )CoO 3-δ 、SmBaCo2O 5+δ 、LaBa 0.5 Sr 0.5 Co2O 5+δ 、SmBa 0.5 Sr 0.5 Co2O 5+δ ,BaGd 0.8 La 0.2 Co2O 6-δ or La 2-x Sr x Fe 2-y-z Ni y Mo z O 6-δ At least one of the above, the inner wall of the anode hole is covered with a nano catalyst material selected from Ni, Fe, Co, FeNi3, Ce 1-x Sm x O 2-δ 、Ce 1- x G x O 2-δ , (La 1-x Sr x )(Co 1-y Fe y ) 3-δ 、(Ba 1-x Sr x )(Co 1-y Fe y ) 3-δ 、(Sm 1-x Sr x )CoO 3-δ 、SmBaCo2O 5+δ 、LaBa 0.5 Sr 0.5 Co2O 5+δ 、SmBa 0.5 Sr 0.5 Co2O 5+δ ,BaGd 0.8 La 0.2 Co2O 6-δ or La 2-x Sr x Fe 2-y-z Ni y Mo z O 6-δ At least one of .

8. The solid oxide electrolysis stack for preparing synthesis gas by high temperature electrolysis according to claim 2, characterized in that: The operating temperature range of the electrolytic cell (100) is 400-1000°C, and the operating voltage between the cathode (3) and the anode (1) is 0.1-2.0V.

9. A high-temperature and high-pressure electrolysis device for preparing synthesis gas, characterized in that: It comprises a high-pressure container and a solid oxide electrolysis stack for preparing synthesis gas by high-temperature electrolysis as described in any one of claims 2-8, wherein the solid oxide electrolysis stack for preparing synthesis gas by high-temperature electrolysis is placed in the cavity of the high-pressure container, and the cavity of the high-pressure container is connected to the cathode chamber and the anode chamber of the solid oxide electrolysis stack for preparing synthesis gas by high-temperature electrolysis.

10. A hydrocarbon fuel synthesis equipment, characterized in that: It comprises the high-temperature and high-pressure electrolysis synthesis gas preparation device, the fuel high-pressure synthesis module, the thermal management module and the intelligent control module as described in claim 9, the high-pressure synthesis gas produced by the high-temperature and high-pressure electrolysis synthesis gas preparation device directly enters the fuel high-pressure synthesis module and is converted into hydrocarbon fuel; the thermal management module comprises a steam generator, a heat exchanger and / or an electric heater for preheating the raw gas and recovering the waste heat of the process gas; the hydrocarbon fuel comprises methanol, ethanol, gasoline, diesel and / or sustainable aviation kerosene.

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