Tubular solid oxide reactor and method for synthesizing ammonia

Abstract

The invention belongs to the technical field of ammonia synthesis, and discloses a tubular solid oxide reactor and an ammonia synthesis method. The tubular solid oxide reactor comprises a tubular solid oxide electrolytic tank, a gas transmission pipe and an ammonia synthesis catalyst, the tubular solid oxide electrolytic tank comprises a fuel electrode supporting pipe body, an electrolyte layer and an air electrode layer, and the ammonia synthesis catalyst is filled in the hollow interior of the fuel electrode supporting pipe body. The gas transmission pipe is communicated with the hollow interior of the fuel electrode supporting pipe body, the electrolyte layer is arranged on the outer surface of the fuel electrode supporting pipe body, and the air electrode layer is arranged on the outer surface of the electrolyte layer. According to the tubular solid oxide reactor disclosed by the invention, the tubular solid oxide electrolytic tank is matched with the ammonia synthesis catalyst, so that green ammonia can be prepared by directly taking water and nitrogen as raw materials, and the tubular solid oxide reactor is clean, environment-friendly and low in cost.

Description

Technical Field

[0001] The invention belongs to the technical field of synthetic ammonia, and in particular relates to a tubular solid oxide reactor and a method for synthesizing ammonia. Background Art

[0002] In addition to being a bulk chemical product mainly used in the production of fertilizers, pharmaceuticals, and synthetic fibers, ammonia is also known as "Hydrogen 2.0". It is a carbon-free hydrogen carrier with a high hydrogen storage density. It can be used as a fuel for high-temperature industries, directly burned to provide energy, or decomposed to produce hydrogen energy for use in hydrogen fuel cells, hydrogen-powered vehicles, metallurgy, chemical industry, and other fields. Ammonia is easier to liquefy, store, and transport than hydrogen. Therefore, storing and transporting hydrogen in the form of ammonia is one of the effective strategies to improve the safety of hydrogen storage and transportation and reduce the cost of hydrogen transportation.

[0003] At present, industrial ammonia synthesis mainly adopts the high temperature and high pressure (300-550℃, 20-30MPa) Haber-Bosch process, which leads to high energy consumption and high carbon dioxide emissions, exacerbating the energy crisis and environmental pollution. Therefore, the development of new green ammonia synthesis technology is of great significance. Electrochemical synthesis of ammonia is regarded as one of the most promising ammonia synthesis processes. It overcomes the thermodynamic limitations of the traditional Haber-Bosch method of ammonia synthesis and helps to promote the low temperature and low pressure of the ammonia synthesis process. However, due to the high bond energy of the nitrogen-nitrogen triple bond, the electrochemical synthesis of ammonia using water and nitrogen as raw materials has slow reaction kinetics, resulting in low ammonia yield and lack of feasibility for industrial application.

[0004] Therefore, how to improve the efficiency of synthetic ammonia remains a technical problem to be solved urgently in this field. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a tubular solid oxide reactor and a method for synthesizing ammonia, which does not require traditional high-pressure conditions and can achieve efficient preparation of green ammonia under milder conditions.

[0006] According to a first aspect of the present invention, there is provided a tubular solid oxide reactor, comprising a tubular solid oxide electrolysis cell, a gas transmission tube and an ammonia synthesis catalyst, wherein the tubular solid oxide electrolysis cell comprises a fuel electrode support tube body, an electrolyte layer and an air electrode layer, the ammonia synthesis catalyst is filled in the hollow interior of the fuel electrode support tube body, the gas transmission tube is connected to the hollow interior of the fuel electrode support tube body, the electrolyte layer is arranged on the outer surface of the fuel electrode support tube body, and the air electrode layer is arranged on the outer surface of the electrolyte layer.

[0007] In some embodiments of the present invention, the ammonia synthesis catalyst includes at least one of an iron-based catalyst, a ruthenium-based catalyst, a metal nitride catalyst and a transition metal catalyst.

[0008] In some embodiments of the present invention, the ammonia synthesis catalyst is an iron catalyst.

[0009] In some embodiments of the present invention, the fuel electrode support tube body has a porous structure.

[0010] In some embodiments of the present invention, the tubular solid oxide electrolysis cell is a tubular oxygen ion conductor electrolysis cell (Solid Oxide Electrolysis Cell, SOEC) or a tubular protonic ceramic electrolysis cell (Protonic Ceramic Electrolysis Cell, PCEC).

[0011] In some embodiments of the present invention, the gas transmission pipe is a porous gas transmission pipe. The wall of the porous gas transmission pipe is provided with a porous structure. The present invention transmits the reaction gas including hydrogen, water vapor and nitrogen through the gas transmission pipe, controls the transmission of the reaction gas by adjusting the length and diameter of the gas transmission pipe and the pore size of the porous structure on the wall of the pipe, and increases the reaction time and contact area between the reaction gas and the ammonia synthesis catalyst.

[0012] In some embodiments of the present invention, the inner diameter of the fuel electrode support tube body is 0.5-5.0 cm.

[0013] In some embodiments of the present invention, the outer diameter of the fuel electrode support tube body is 0.6-5.5 cm.

[0014] In some embodiments of the present invention, the fuel electrode support tube body has a tube length of 5-50.0 cm.

[0015] In some embodiments of the present invention, current collecting layers are provided on both the inner surface and the outer surface of the tubular solid oxide electrolytic cell, and the current collecting layers are connected to wires.

[0016] In some embodiments of the present invention, the material of the fuel electrode support tube body includes a Ni-based material mixed with an electrolyte, a Ni-based material modified by Fe impregnation, metal Pd, Ag-Pd alloy, SrTi 0.6 Fe 0.4 O 3-δ (STF), La x Sr 1-x Ti 1- y Ru y O 3-δ(LSTR) or any of the perovskite materials mixed with electrolytes.

[0017] In some embodiments of the present invention, the material of the fuel electrode support tube body is a Ni-based material mixed with an electrolyte, wherein the mass ratio of the Ni-based material to the electrolyte is (1-3):1.

[0018] In some embodiments of the present invention, the electrolyte of the electrolyte layer comprises Y 0.08 Zr 0.92 O 2-δ (YSZ), Gd 0.1 Ce 0.9 O 1.95 (GDC), BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3-δ (BCZYYb), BaCe 0.7 Zr 0.1 Y 0.2 O 3-δ (BCZY), BaCe 0.9 Y 0.1 O 3-δ (BCY) or BaZr 0.8 Y 0.2 O 3-δ Any of (BZY).

[0019] In some embodiments of the present invention, when the tubular solid oxide electrolytic cell is a tubular oxygen ion conductor electrolytic cell (tubular SOEC), the electrolyte in the electrolyte layer is an oxygen ion conductor, including Y 0.08 Zr 0.92 O 2-δ (YSZ) or Gd 0.1 Ce 0.9 O 1.95 (GDC).

[0020] In some embodiments of the present invention, when the tubular solid oxide electrolytic cell is a tubular proton ceramic electrolytic cell (tubular PCEC), the electrolyte in the electrolyte layer is a proton conductor, including BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3-δ (BCZYYb), BaCe 0.7 Zr 0.1 Y 0.2 O 3-δ (BCZY), BaCe 0.9 Y 0.1 O 3-δ(BCY) or BaZr 0.8 Y 0.2 O 3-δ Any of (BZY).

[0021] In some embodiments of the present invention, the material of the air electrode includes a perovskite material such as La 0.8 Sr 0.2 MnO 3-δ (LSM), La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF), Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ (BSCF), BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ (BCFZY), PrBa 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 5+δ (PBSCF) or any one of the perovskite materials mixed with electrolyte.

[0022] In some embodiments of the present invention, the material of the air electrode is a perovskite material mixed with an electrolyte, wherein the mass ratio of the perovskite material to the electrolyte is (1-3):1, preferably 1:1.

[0023] In some embodiments of the present invention, the area of ​​the air electrode layer is 1-10 cm 2 The effective area of ​​the tubular solid oxide reactor of the present invention depends on the area of ​​the air electrode layer on the outer surface of the tube.

[0024] In some embodiments of the present invention, the method for preparing the tubular solid oxide reactor comprises the following steps:

[0025] preparing a fuel electrode support tube blank;

[0026] Sintering the fuel electrode support tube blank for the first time to obtain a fuel electrode support tube body;

[0027] An electrolyte layer is prepared on the outer surface of the fuel electrode support tube body, and a tubular fuel electrode||electrolyte structure is obtained by a second sintering;

[0028] An air electrode layer is prepared on the outer surface of the electrolyte layer, and a tubular fuel electrode||electrolyte||air electrode structure is obtained through a third sintering, namely a tubular solid oxide electrolytic cell;

[0029] Filling an ammonia synthesis catalyst into the hollow interior of the fuel electrode support tube body;

[0030] One end of the gas transmission tube is placed in the hollow interior of the fuel electrode support tube body and communicated with the hollow interior of the fuel electrode support tube body to obtain the tubular solid oxide reactor.

[0031] In some embodiments of the present invention, the method for preparing the tubular solid oxide reactor further includes the following steps: coating a current collecting layer on the inner surface and the outer surface of the tubular solid oxide electrolytic cell, and connecting the current collecting layer with a wire.

[0032] In some embodiments of the present invention, the temperature of the first sintering is 900-1100°C.

[0033] In some embodiments of the present invention, the temperature of the second sintering is 1300-1500°C.

[0034] In some embodiments of the present invention, the temperature of the third sintering is 800-1000°C.

[0035] In some embodiments of the present invention, a pore former is added when preparing the fuel electrode support tube blank.

[0036] In some embodiments of the present invention, the amount of the pore former added is 5-15% of the total mass of the remaining raw materials for preparing the fuel electrode support tube blank.

[0037] In some embodiments of the present invention, the pore former is graphite.

[0038] In some embodiments of the present invention, the method for preparing the electrolyte layer and the method for preparing the air electrode layer is an immersion pulling method.

[0039] The second aspect of the present invention provides a method for synthesizing ammonia, using water vapor and nitrogen as main reaction raw materials, adopting the tubular solid oxide reactor described in the first aspect of the present invention to electrolyze water and synthesize ammonia, and producing ammonia in the hollow interior of the fuel electrode support tube body.

[0040] In some embodiments of the present invention, the method for synthesizing ammonia comprises the following steps:

[0041] connecting the tubular solid oxide reactor to an electrochemical workstation;

[0042] Passing the reaction raw materials into the tubular solid oxide reactor;

[0043] The tubular solid oxide electrolysis cell electrolyzes water vapor to produce hydrogen;

[0044] During the electrolysis process, under the catalytic action of the ammonia synthesis catalyst, the hydrogen and the nitrogen react to produce ammonia.

[0045] In some embodiments of the present invention, when the tubular solid oxide electrolytic cell is a tubular SOEC, the process of introducing the reaction raw materials into the tubular solid oxide reactor comprises:

[0046] Water vapor, hydrogen and nitrogen are introduced into the hollow interior of the fuel electrode support tube body through a gas transmission tube, and the air electrode is in contact with the air.

[0047] In some embodiments of the present invention, when the tubular solid oxide electrolytic cell is a tubular PCEC, the process of introducing the reaction raw materials into the tubular solid oxide reactor comprises:

[0048] Hydrogen and nitrogen are introduced into the hollow interior of the fuel electrode support tube body through a gas transmission tube, and the air electrode is in contact with air and water vapor.

[0049] In some embodiments of the present invention, the voltage of the electrolysis is from open circuit potential to 1.2-1.6V.

[0050] In some embodiments of the present invention, the reaction temperature is 400-850°C.

[0051] In some embodiments of the present invention, the reaction temperature is 400-750°C.

[0052] In some embodiments of the present invention, the reaction temperature is 500-700°C.

[0053] In some embodiments of the present invention, there are multiple tubular solid oxide reactors, and the multiple tubular solid oxide reactors are connected in series and then connected to the electrochemical workstation. The present invention achieves efficient and large-scale preparation of green ammonia by connecting multiple tubular solid oxide reactors in series.

[0054] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0055] (1) In the tubular solid oxide reactor provided by the present invention, an ammonia synthesis catalyst is filled in the hollow interior of the fuel electrode support tube body. Through the combination of the tubular solid oxide electrolytic cell and the ammonia synthesis catalyst, green ammonia can be directly prepared using water and nitrogen as raw materials, which is clean, environmentally friendly and low-cost. In addition, the tubular solid oxide reactors can be connected in series to achieve efficient and large-scale synthesis of green ammonia.

[0056] (2) The method for synthesizing ammonia provided by the present invention utilizes a tubular solid oxide electrolytic cell to electrolyze water to produce hydrogen. The generated hydrogen reacts with the introduced nitrogen gas under the action of an ammonia synthesis catalyst to produce ammonia. By combining chemical catalysis and electrochemical catalysis methods, the nitrogen gas is activated and the reaction activity of the nitrogen-nitrogen triple bond is increased, thereby effectively improving the ammonia production efficiency of the existing electrochemical ammonia synthesis process. Green ammonia is efficiently synthesized in a tubular solid oxide reactor, wherein the rate of synthesizing ammonia can reach 46.11×10 -10 mol NH3 ·s -1 cm -2 . BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a schematic structural diagram of a tubular solid oxide reactor of the present invention;

[0058] Figure 2 is a schematic cross-sectional structure diagram of a tubular solid oxide reactor of the present invention;

[0059] Figure 3 A physical diagram of a tubular solid oxide electrolytic cell of the present invention;

[0060] Figure 4 A physical diagram of a tubular solid oxide reactor of the present invention;

[0061] Figure 5 It is a schematic structural diagram of a plurality of tubular solid oxide reactors connected in series according to the present invention;

[0062] Figure 6 This is a schematic diagram of synthesizing ammonia using the tubular PCEC reactor of Example 1 of the present invention;

[0063] Figure 7 This is a graph showing the change in current over time of the tubular PCEC reactor of Example 1 of the present invention when the reactor is operated at 700° C. and an electrolysis voltage of 1.2 V for 6 hours;

[0064] Figure 8 The graphs are of the ammonia synthesis rate of the tubular PCEC reactor of Example 1 of the present invention and the tubular PCEC reactor without an ammonia synthesis catalyst (control group) respectively running at 700° C. and an electrolysis voltage of 1.2 V within 2 hours;

[0065] Fig. 9 This is a schematic diagram of synthesizing ammonia using the tubular SOEC reactor of Example 2 of the present invention;

[0066] Fig.10 The graphs are of the ammonia synthesis rate of the tubular SOEC reactor of Example 2 of the present invention and the tubular SOEC reactor without an ammonia synthesis catalyst (control group) operating at 750° C. and an electrolysis voltage of 1.2 V for 2 hours.

[0067] Figure numerals: 100, tubular solid oxide electrolytic cell; 110, fuel electrode support tube body; 120, electrolyte layer; 130, air electrode layer; 200, gas transmission tube; 210, porous structure; 300, ammonia synthesis catalyst. DETAILED DESCRIPTION

[0068] In the description of the present invention, it is necessary to understand that the orientation or positional relationship indicated by the terms upper, lower, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0069] In the description of the present invention, the meaning of "plurality" is more than two. If there is a description of "first", "second", etc., it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0070] Embodiments of the present invention are described in detail below. The described embodiments are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0071] refer to Figure 1 and Figure 2 As shown, the tubular solid oxide reactor of the present invention comprises a tubular solid oxide electrolysis cell 100, a gas transmission tube 200 and an ammonia synthesis catalyst 300, wherein the tubular solid oxide electrolysis cell 100 comprises a fuel electrode support tube body 110, an electrolyte layer 120 and an air electrode layer 130, the ammonia synthesis catalyst 300 is filled in the hollow interior of the fuel electrode support tube body 100, the gas transmission tube 200 is connected to the hollow interior of the fuel electrode support tube body 100, a porous structure 210 is provided on the tube wall of the gas transmission tube 200, the electrolyte layer 120 is provided on the outer surface of the fuel electrode support tube body 100, and the air electrode layer 130 is provided on the outer surface of the electrolyte layer 120.

[0072] It can be understood that the filling amount of the ammonia synthesis catalyst of the present invention depends on the tube length and tube inner diameter of the fuel electrode supporting tube body.

[0073] In some embodiments of the present invention, the prepared tubular solid oxide electrolytic cell is shown in the figure below: Figure 3 As shown, the tube length is 6.2 cm, the outer diameter of the tube is 0.9 cm, and the inner diameter of the tube is 0.75 cm.

[0074] In some embodiments of the present invention, the prepared tubular solid oxide reactor is as follows: Figure 4 As shown, Figure 4 (a), (b), and (c) are three tubular solid oxide reactors with different air electrode areas. Specifically, the "S1" area in (a) indicates that the area of ​​the air electrode is 1 cm 2 The "S2" area in (b) indicates that the area of ​​the air electrode is 5 cm 2 The “S3” area in (c) indicates that the area of ​​the air electrode is 10 cm 2 .

[0075] In some embodiments of the present invention, multiple tubular solid oxide reactors are connected in series. Figure 5 As shown, Figure 5 This is a schematic diagram of the structure of multiple tubular solid oxide reactors connected in series (the gas transmission pipe is not shown).

[0076] In some embodiments of the present invention, the tubular solid oxide reactor is a tubular oxygen ion conductor reactor or a tubular proton ceramic reactor.

[0077] The tubular solid oxide reactor and the method for synthesizing ammonia provided by the present invention are described in detail below through specific examples. Unless otherwise specified, the raw materials, reagents or devices used in the examples can be obtained from conventional commercial channels or can be obtained by existing technical methods. Unless otherwise specified, the test or testing methods are conventional methods in the art.

[0078] Example 1

[0079] A tubular PCEC reactor is prepared by a preparation method comprising the following steps:

[0080] Mixing NiO, BCZYYb and a graphite pore former, and molding to obtain a fuel electrode support tube blank; wherein the mass ratio of NiO to BCZYYb is 6.5:3.5, and the addition amount of the graphite pore former is 10% of the total mass of NiO and BCZYYb;

[0081] The fuel electrode support tube blank is first sintered at 1000°C to remove the graphite pore-forming agent, thereby obtaining a fuel electrode support tube body having a certain strength;

[0082] A layer of electrolyte material (BCZYYb) is coated on the outer surface of the fuel electrode support tube by the immersion and pulling method, and a second sintering is performed at 1400°C to form an electrolyte layer, thereby obtaining a high-strength tubular fuel electrode||electrolyte structure;

[0083] A layer of air electrode material (a mixture of LSCF and BCZYYb in a mass ratio of 1:1) was coated on the outer surface of the electrolyte layer by the immersion pulling method, and the air electrode layer was formed by the third sintering at 900 °C to obtain a tubular fuel electrode||electrolyte||air electrode structure, namely, tubular PCEC; the area of ​​the air electrode layer was 1 cm 2 , the length of the tubular PCEC is 6.2 cm, the outer diameter is 0.9 cm, and the inner diameter is 0.75 cm;

[0084] Silver paste is coated on the inner and outer surfaces of the tubular PCEC, which is used as the current collecting layer after drying, and a silver mesh is wrapped on the outer surface and led out through a silver wire;

[0085] Filling 1 g of iron catalyst into the hollow interior of the fuel electrode support tube body;

[0086] One end of the porous gas transmission tube is placed in the hollow interior of the fuel electrode support tube body to obtain a tubular proton ceramic reactor (tubular PCEC reactor).

[0087] refer to Figure 6 As shown, a method for synthesizing ammonia, using the above-mentioned tubular PCEC reactor, comprises the following steps:

[0088] Connect the silver wire of the tubular PCEC reactor to the electrochemical workstation;

[0089] 75 mL min-1 of gas was introduced into the tube of the tubular PCEC (i.e., the hollow interior of the fuel electrode support tube body) through the porous gas transmission tube. -1 of hydrogen and 25 mL min -1 A nitrogen mixture of 50 mL / min humidified at room temperature was introduced outside the tubular PCEC. -1 A mixture of 3% water vapor and 97% air.

[0090] The tubular PCEC reactor was operated at 700°C and an electrolysis voltage of 1.2V to electrolyze water and synthesize ammonia, and ammonia gas was produced in the tube of the tubular PCEC.

[0091] It can be understood that the tubular PCEC reactor electrolyzes water at the air electrode.

[0092] Synthetic ammonia performance test

[0093] 1. Operation stability test

[0094] like Figure 7 As shown, the current variation curve of the tubular PCEC reactor of Example 1 is operated at 700°C and an electrolysis voltage of 1.2V for 6 hours. It can be seen that the tubular PCEC reactor exhibits good chemical / electrochemical operation stability.

[0095] 2. Synthetic ammonia efficiency test

[0096] The product gas in the tubular PCEC reactor was heated to a concentration of 0.01 mol·L -1 The ammonia yield in the absorption liquid was tested by absorption of dilute sulfuric acid.

[0097] The tubular PCEC reactor of Example 1 and the tubular PCEC reactor without an ammonia synthesis catalyst in the tube (control group) were operated at 700° C. and an electrolysis voltage of 1.2 V for 2 h. The test results are as follows: Figure 8 shown.

[0098] from Figure 8 It can be seen that the ammonia synthesis rate of Example 1 is 46.11×10 -10 mol NH3 ·s -1 cm -2 , that is, the electrolytic cell generates 46.11×10 per square centimeter of effective area per second. -10 moles of ammonia; the synthesis rate of ammonia in the control group was 0.75×10 -10 mol NH3 ·s -1 cm -2 It can be seen that in Example 1, the ammonia synthesis catalyst is loaded in the tube of the tubular solid oxide electrolytic cell, and the performance of synthesizing ammonia is improved by about 2 orders of magnitude through chemical / electrochemical catalysis.

[0099] Example 2

[0100] A tubular SOEC reactor is prepared by a preparation method comprising the following steps:

[0101] Mixing NiO, YSZ and a graphite pore former, and molding them to obtain a fuel electrode support tube blank; wherein the mass ratio of NiO to YSZ is 6.5:3.5, and the amount of the graphite pore former added is 10% of the total mass of NiO and YSZ;

[0102] The fuel electrode support tube blank is first sintered at 1000°C to remove the graphite pore-forming agent, thereby obtaining a fuel electrode support tube body having a certain strength;

[0103] A layer of electrolyte material (YSZ) is coated on the outer surface of the fuel electrode support tube by the immersion and pulling method, and a second sintering is performed at 1400°C to form an electrolyte layer, thereby obtaining a high-strength tubular fuel electrode||electrolyte structure;

[0104] A layer of air electrode material (a mixture of LSCF and GDC in a mass ratio of 1:1) was coated on the outer surface of the electrolyte layer by the dip-coating method, and the air electrode layer was formed by the third sintering at 900°C to obtain a tubular fuel electrode||electrolyte||air electrode structure, i.e., a tubular SOEC; the area of ​​the air electrode layer was 1 cm 2 , the length of the tubular PCEC is 6.2 cm, the outer diameter is 0.9 cm, and the inner diameter is 0.75 cm;

[0105] Silver paste is coated on the inner and outer surfaces of the tubular SOEC, which is used as the current collecting layer after drying, and a silver mesh is wrapped on the outer surface and led out through a silver wire;

[0106] Filling 1 g of iron catalyst into the hollow interior of the fuel electrode support tube body;

[0107] One end of the porous gas transmission tube is placed in the hollow interior of the fuel electrode support tube body to prepare a tubular oxygen ion conductor reactor (tubular SOEC reactor).

[0108] refer to Fig. 9 As shown, a method for synthesizing ammonia, using the above-mentioned tubular SOEC reactor, comprises the following steps:

[0109] Connect the silver wire of the tubular SOEC reactor to the electrochemical workstation;

[0110] A mixed gas of water vapor, hydrogen and nitrogen is introduced into the tube of the tubular SOEC (i.e., the hollow interior of the fuel electrode support tube body) through a porous gas transmission tube, and air at room temperature is introduced outside the tube of the tubular SOEC;

[0111] The tubular SOEC reactor was operated at 700°C and an electrolysis voltage of 1.2V to electrolyze water and synthesize ammonia, and ammonia gas was produced in the tube of the tubular SOEC.

[0112] It is understood that the tubular SOEC reactor electrolyzes water at the fuel electrode.

[0113] Ammonia synthesis efficiency test

[0114] The product gas in the tubular SOEC reactor was heated to a concentration of 0.01 mol·L -1 The ammonia yield in the absorption liquid was tested by absorption of dilute sulfuric acid.

[0115] The tubular SOEC reactor of Example 2 and the tubular SOEC reactor without ammonia synthesis catalyst in the tube (control group) were operated at 750°C and an electrolysis voltage of 1.2V for 2 hours. The test results are as follows: Fig.10 shown.

[0116] from Fig.10 It can be seen that the ammonia synthesis rate of Example 2 is 3.77×10 -10 mol NH3 ·s -1 cm -2 ; The ammonia synthesis rate of the control group was 0.16×10 -10 mol NH3 ·s -1 cm -2 It can be seen that in Example 2, the ammonia synthesis catalyst is loaded in the tube of the tubular solid oxide electrolytic cell, and the ammonia synthesis performance is also significantly improved through chemical / electrochemical catalysis.

[0117] The preferred embodiments of the present invention are specifically described above, but the invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A tubular solid oxide reactor, characterized in that: It includes a tubular solid oxide electrolysis cell, a gas transmission tube and an ammonia synthesis catalyst. The tubular solid oxide electrolysis cell includes a fuel electrode support tube body, an electrolyte layer and an air electrode layer. The ammonia synthesis catalyst is filled in the hollow interior of the fuel electrode support tube body. The gas transmission tube is connected to the hollow interior of the fuel electrode support tube body. The electrolyte layer is arranged on the outer surface of the fuel electrode support tube body. The air electrode layer is arranged on the outer surface of the electrolyte layer.

2. The tubular solid oxide reactor according to claim 1, characterized in that: The ammonia synthesis catalyst includes at least one of an iron-based catalyst, a ruthenium-based catalyst, a metal nitride catalyst and a transition metal catalyst.

3. The tubular solid oxide reactor according to claim 1, characterized in that: The fuel electrode support tube body has a porous structure.

4. The tubular solid oxide reactor according to claim 1, characterized in that: The material of the fuel electrode support tube body includes a Ni-based material mixed with an electrolyte, a Ni-based material modified by Fe impregnation, metal Pd, Ag-Pd alloy, SrTi 0.6 Fe 0.4 O 3-δ ,La x Sr 1-x Ti 1-y Ru y O 3-δ Or any one of the perovskite materials mixed with electrolyte.

5. The tubular solid oxide reactor according to claim 1, characterized in that: The electrolyte of the electrolyte layer includes Y 0.08 Zr 0.92 O 2-δ , Gd 0.1 Ce 0.9 O 1.95 ,BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3-δ ,BaCe 0.7 Zr 0.1 Y 0.2 O 3-δ ,BaCe 0.9 Y 0.1 O 3-δ or BaZr 0.8 Y 0.2 O 3-δ Any one of .

6. The tubular solid oxide reactor according to claim 1, characterized in that: The material of the air electrode includes La 0.8 Sr 0.2 MnO 3-δ ,La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ , Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ 、BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ , PrBa 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 5+δ Or any one of the perovskite materials mixed with electrolyte.

7. A method for synthesizing ammonia, characterized in that: With water vapor and nitrogen as main reaction raw materials, the tubular solid oxide reactor described in any one of claims 1 to 6 is used to electrolyze water and synthesize ammonia, and ammonia is produced in the hollow interior of the fuel electrode support tube body.

8. The method according to claim 7, characterized in that The following steps are involved: connecting the tubular solid oxide reactor to an electrochemical workstation; Passing the reaction raw materials into the tubular solid oxide reactor; The tubular solid oxide electrolysis cell electrolyzes water vapor to produce hydrogen; During the electrolysis process, under the catalytic action of the ammonia synthesis catalyst, the hydrogen and the nitrogen react to produce ammonia.

9. The method according to claim 8, characterized in that The voltage of the electrolysis is an open circuit potential of 1.2-1.6V; the temperature of the reaction is 400-850°C.

10. The method according to claim 8, characterized in that There are multiple tubular solid oxide reactors, and the multiple tubular solid oxide reactors are connected in series and then connected to the electrochemical workstation.

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