A foam metal enhanced heat transfer carbon assisted solid oxide electrolytic cell

Abstract

The present invention provides a foam metal enhanced heat transfer carbon-assisted solid oxide electrolytic cell, comprising a cathode flow channel, a cathode, an electrolyte, an anode and an anode cavity, water vapor is introduced into the cathode flow channel as an oxidant to cause a reduction reaction, the anode cavity contains foam metal, carbon fuel and a catalyst, water vapor is introduced into the anode cavity as an in-situ gasification medium, water vapor and carbon fuel undergo a carbon gasification reaction to generate CO and H2, oxygen ions generated by the cathode are transferred to the anode through the electrolyte, and undergo an oxidation reaction with CO and H2 generated in the anode cavity, and part of the CO generated by the carbon gasification reaction undergoes a water gas replacement reaction with water vapor at the anode to generate CO2 and H2; the foam metal achieves effective regulation of temperature distribution by enhancing heat transfer. The present invention can reduce the energy consumption of the carbon-assisted electrolytic cell, and achieve simultaneous generation of fuel gas at the cathode and anode, significantly improving the working efficiency of the electrolytic cell.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic cells, in particular to a foam metal enhanced heat transfer carbon assisted solid oxide electrolytic cell. Background Art

[0002] Hydrogen is the clean energy carrier with the highest energy density by weight among various gas fuels. In particular, green hydrogen produced from renewable energy sources such as wind, solar and bioenergy is believed to play an important role in the future low-carbon energy system. Currently, 50% of the world's hydrogen is produced by steam reforming of methane using natural gas or coal-bed methane resources, which is called "grey hydrogen" or "blue hydrogen".

[0003] Solid Oxide Electrolysis Cell (SOEC) is a high-temperature electrolysis cell suitable for converting excess renewable energy into hydrogen fuel. Compared with low-temperature electrolysis cells, most of the energy required by SOEC exists in the form of heat, and its electricity demand is relatively low. In addition, SOEC has a high operating temperature, does not require precious metal catalysts, and has low cost. It is an advanced energy device with great development potential and market prospects.

[0004] The use of a carbon-assisted solid oxide electrolysis cell (CA-SOEC) with integrated anode and oxidation reaction to react with the introduced water vapor for in-situ gasification can reduce the overpotential of the anode and improve the kinetics of the anode reaction, thereby improving energy efficiency. However, the high operating temperature and uneven temperature distribution of CA-SOEC lead to severe battery degradation and low life, limiting its large-scale use and promotion. Maintaining the high kinetic performance of CA-SOEC while reducing its operating temperature is the key to the further development of CA-SOEC. Summary of the invention

[0005] The purpose of the present invention is to provide a foam metal enhanced heat transfer carbon-assisted solid oxide electrolysis cell in response to the above problems, introduce water vapor into the anode cavity as an in-situ gasification medium, and improve the heat transfer efficiency of the anode cavity by uniformly doping carbon fuel into the foam metal with high thermal conductivity, so as to effectively regulate the temperature distribution.

[0006] To this end, the above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0007] A foam metal enhanced heat transfer carbon assisted solid oxide electrolytic cell, the electrolytic cell comprising a cathode flow channel, a cathode, an electrolyte, an anode and an anode cavity arranged in sequence, characterized in that:

[0008] Water vapor is introduced into the cathode flow channel as an oxidant, and a reduction reaction occurs at the junction of the cathode and the electrolyte to generate H2;

[0009] The anode cavity contains foam metal, carbon fuel and catalyst. Water vapor is introduced into the anode cavity as an in-situ gasification medium. The water vapor and the carbon fuel undergo carbon gasification reaction to generate CO and H2.

[0010] The oxygen ions produced at the cathode are transferred to the anode through the electrolyte and undergo oxidation reaction with the CO and H2 produced in the anode chamber to generate CO2 and H2O.

[0011] Part of the CO produced by the carbon gasification reaction undergoes a water-gas replacement reaction with water vapor in the anode to generate CO2 and H2;

[0012]

[0013] The foam metal in the anode cavity reduces the thermal resistance of the system by enhancing heat transfer, thereby reducing energy consumption and achieving effective regulation of temperature distribution.

[0014] The foam metal in the anode cavity is a porous metal material with high gas diffusion permeability and high mechanical stability;

[0015] The catalyst in the anode cavity is a catalyst for the carbon gasification reaction; the carbon gasification reaction catalyst can promote the reaction of water vapor, carbon dioxide and carbon fuel to generate H2 and CO, change the reaction path, reduce the reaction energy barrier, and ensure the stability of the output performance of the electrolytic cell after the anode flow is increased.

[0016] The carbon fuel in the anode cavity is an inorganic carbon fuel.

[0017] Water vapor as a gasification medium can increase the carbon gasification reaction rate, mass transfer rate and electrochemical activity, and can significantly reduce the performance degradation of the electrolytic cell caused by concentration polarization and activation polarization, thereby greatly reducing the working potential and energy consumption. The anode cavity uses a foam metal-carbon fuel composite material instead of a single carbon fuel, which further reduces energy consumption and improves the working performance of CA-SOEC by enhancing heat transfer.

[0018] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0019] As a preferred technical solution of the present invention: the foam metal in the anode cavity includes but is not limited to Cu-Mn, Ni-Fe and other foam materials.

[0020] As a preferred technical solution of the present invention: the catalyst in the anode cavity includes alkaline earth metal catalysts such as CaO, MgO, etc., iron-based catalysts and multi-component composite catalysts.

[0021] As a preferred technical solution of the present invention: the inorganic carbon fuel includes coal, coke, activated carbon, graphite, fiberboard, carbon black or biochar. Coal, coke, activated carbon, graphite, fiberboard, carbon black or biochar are carbon fuels with a wide range of sources, which are conducive to reducing the manufacturing cost of CA-SOEC and are suitable for large-scale application of CA-SOEC.

[0022] As a preferred technical solution of the present invention: the carbon fuel is uniformly doped in the foam metal.

[0023] As a preferred technical solution of the present invention: the anode and cathode are both made of porous Ni-YSZ material; the electrolyte is made of dense YSZ-SDC double-layer material. The cathode and anode materials are porous enough for gas transmission, and the electrolyte material is dense enough to separate the gas generated by the anode and cathode. Anode catalysts such as Ni promote the water vapor replacement reaction, thereby producing more fuel gas H2, which has a faster H2 diffusion rate and higher electrochemical activity, which is beneficial to improving the output performance of CA-SOEC.

[0024] As a preferred technical solution of the present invention: the water vapor flow rate in the cathode flow channel is 10 to 800 mL / min;

[0025] The water vapor flow rate in the anode chamber is 10 to 800 mL / min.

[0026] It should be noted that this range is the recommended flow range, and the water vapor flow rates of the cathode and anode can be different. At this water vapor flow rate, the operating temperature in the CA-SOEC is stable, and the output performance of the CA-SOEC is stable.

[0027] As a preferred technical solution of the present invention: the anode chamber discharges a mixed gas containing H2, CO, CO2 and H2O. The mixed gas produced in the anode chamber can be used as a raw material for synthesizing high value-added hydrocarbon fuels such as methanol, basically achieving zero carbon emissions and higher energy utilization conversion efficiency.

[0028] As a preferred technical solution of the present invention: the electrolytic cell is a tubular electrolytic cell;

[0029] The length of the tubular electrolytic cell is 7 cm, the width of the cathode flow channel is 1750 μm, the thickness of the cathode is 24 μm; the thickness of the anode is 400 μm, the thickness of the electrolyte is 8 μm, and the operating voltage of the tubular electrolytic cell is 0.8V to -0.1V.

[0030] As a preferred technical solution of the present invention: the operating temperature range of the carbon-assisted solid oxide electrolytic cell is 650-850°C. Within this temperature range, it is beneficial to reduce the material and preparation costs of CA-SOEC and improve the long-term operation stability of CA-SOEC. Within this temperature range, the carbon gasification reaction is an endothermic reaction, and the foam metal quickly conducts the heat generated by the overpotential and electrochemical reaction, significantly reducing the thermal resistance of the system, thereby reducing energy consumption, which is beneficial to improving the output performance of CA-SOEC, and effectively avoiding local temperature rise and uniform temperature distribution.

[0031] The present invention provides a foam metal enhanced heat transfer carbon-assisted solid oxide electrolytic cell, comprising a cathode flow channel, a cathode, an electrolyte, an anode and an anode cavity, water vapor is introduced into the cathode flow channel as an oxidant to cause a reduction reaction, the anode cavity contains foam metal, carbon fuel and a catalyst, water vapor is introduced into the anode cavity as an in-situ gasification medium, water vapor and carbon fuel undergo a carbon gasification reaction to generate CO and H2, oxygen ions generated by the cathode are transferred to the anode through the electrolyte, and undergo an oxidation reaction with CO and H2 generated in the anode cavity, and part of the CO generated by the carbon gasification reaction undergoes a water gas replacement reaction with water vapor at the anode to generate CO2 and H2; the foam metal achieves effective regulation of temperature distribution by enhancing heat transfer. The present invention can reduce the energy consumption of the carbon-assisted electrolytic cell, and achieve simultaneous generation of fuel gas at the cathode and anode, significantly improving the working efficiency of the electrolytic cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the distribution positions of various reactions in the foam metal enhanced heat transfer carbon-assisted solid oxide electrolysis cell provided by the present invention.

[0033] Figure 2 The specific temperature control effect diagram of the foam metal enhanced heat transfer carbon-assisted solid oxide electrolytic cell provided by the present invention, wherein: (a) is the specific temperature control effect diagram of the CA-SOEC with enhanced heat transfer by adding foam metal; (b) is the specific temperature control effect diagram of the traditional CA-SOEC. DETAILED DESCRIPTION

[0034] The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

[0035] When the operating voltage is 0.5V, the inlet gas is 99% H2O and 1% H2, the cathode and anode inlet gas flow rates are 800mL / min, and the temperature is 1073K, combined with the specific operating parameters given in Table 1, the preliminary simulation results of the present invention are given.

[0036] Table 1 Model parameters

[0037]

[0038] The power consumption, fuel generation rate, and maximum and minimum temperatures are shown in Table 2. The structure, electrode materials, and input parameters (gas temperature and composition) of the enhanced heat transfer carbon-assisted electrolytic cell with added foam metal are consistent with those of the traditional carbon-assisted electrolytic cell without added foam metal. The only difference is the change in the thermal properties of the anode cavity caused by the addition of foam metal, such as thermal conductivity, heat capacity, and density.

[0039] Table 2 Model results

[0040] Metal foam No foam metal Power consumption W 7.509 9.796 Hydrogen molar yield mol / s 1.544E-04 1.651E-04 Carbon monoxide molar yield mol / s 1.285E-04 1.208E-04 Maximum temperature K 1077.9 1182.1 Minimum temperature K 1049.6 1010.0 Maximum temperature gradient K / m 66771 231150

[0041] As shown in Table 2, after adding foamed metal, the power consumption is reduced by more than 20%, while still maintaining a relatively high fuel yield, significantly improving the working efficiency of the carbon-assisted electrolysis cell.

[0042] In addition, if Figure 2 As shown, after adding foam metal, the heat transfer rate is increased, no obvious local temperature rise occurs in the electrolytic cell, and the maximum temperature of the electrolytic cell is reduced, the temperature difference of the electrolytic cell is reduced, and the temperature distribution is uniform, showing good temperature regulation ability.

[0043] The above-mentioned specific implementation methods are used to explain the present invention and are only preferred embodiments of the present invention, rather than limiting the present invention. Any modifications, equivalent substitutions, improvements, etc. made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A foam metal enhanced heat transfer carbon assisted solid oxide electrolytic cell, the electrolytic cell comprising a cathode flow channel, a cathode, an electrolyte, an anode and an anode cavity arranged in sequence, characterized in that: Water vapor is introduced into the cathode flow channel as an oxidant to cause a reduction reaction; The anode cavity contains foam metal, carbon fuel and catalyst. Water vapor is introduced into the anode cavity as an in-situ gasification medium. The water vapor and the carbon fuel undergo carbon gasification reaction to generate CO and H2. The oxygen ions produced at the cathode are transferred to the anode through the electrolyte and undergo oxidation reaction with the CO and H2 produced in the anode cavity. Part of the CO produced by the carbon gasification reaction undergoes a water-gas replacement reaction with water vapor in the anode to generate CO2 and H2; The foam metal in the anode cavity reduces the thermal resistance of the system by enhancing heat transfer; The foam metal in the anode cavity is a porous metal material with high gas diffusion permeability and high mechanical stability; The catalyst in the anode chamber is a catalyst for carbon gasification reaction; The carbon fuel in the anode cavity is an inorganic carbon fuel; The inorganic carbon fuel includes coal, coke, activated carbon, graphite, fiberboard, carbon black or biochar; The anode and cathode are both made of porous Ni-YSZ material; the electrolyte is made of dense YSZ-SDC double-layer material; The water vapor flow rate in the cathode flow channel is 10 to 800 mL / min; The water vapor flow rate in the anode chamber is 10 to 800 mL / min; The electrolytic cell is a tubular electrolytic cell; The length of the tubular electrolytic cell is 7 cm, the width of the cathode flow channel is 1750 μm, the thickness of the cathode is 24 μm; the thickness of the anode is 400 μm, the thickness of the electrolyte is 8 μm, and the operating voltage of the tubular electrolytic cell is 0.8V to -0.1V.

2. The foam metal enhanced heat transfer carbon assisted solid oxide electrolytic cell according to claim 1, characterized in that: The foam metal in the anode cavity includes Cu-Mn and Ni-Fe foam materials.

3. The foam metal enhanced heat transfer carbon assisted solid oxide electrolytic cell according to claim 1, characterized in that: The catalyst in the anode cavity includes an alkaline earth metal catalyst, an iron catalyst and a multi-component composite catalyst.

4. The foam metal enhanced heat transfer carbon assisted solid oxide electrolytic cell according to claim 1, characterized in that: The carbon fuel is uniformly doped in the foam metal.

5. The foam metal enhanced heat transfer carbon assisted solid oxide electrolytic cell according to claim 1, characterized in that: The anode chamber is discharged with a mixed gas containing H2, CO, CO2 and H2O.

6. The foam metal enhanced heat transfer carbon assisted solid oxide electrolytic cell according to any one of claims 1 to 5, characterized in that: The operating temperature range of the electrolytic cell is 650-850°C.

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