High-temperature solid oxide fuel cell power generation system and method coupled with methanol synthesis
By coupling a high-temperature solid oxide fuel cell power generation system for methanol synthesis, H2, CO and CH4 in the purge gas are directly used as SOFC fuel for electrochemical reaction, which solves the problem of low energy utilization in purge gas treatment and realizes efficient resource utilization and combined heat and power.
Patent Information
- Application Number
- CN202511845438.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-02-24
AI Technical Summary
In existing technologies, the treatment of purge gas in methanol synthesis processes has low energy efficiency, high equipment investment and operating costs, resulting in lengthy process flow and increased energy consumption.
A high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis is adopted. Through a tubular reactor and SOFC power generation system, H2, CO and CH4 in the purge gas are directly used as SOFC fuel to generate electricity through electrochemical reaction, and the fuel utilization rate is further improved through internal reforming reaction.
It enables efficient resource utilization of released gas, reduces equipment investment and operation and maintenance costs, realizes combined heat and power, and improves the optimization of the energy cycle system.
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Figure CN121565901A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of purge gas resource utilization technology, and in particular to a high-temperature solid oxide fuel cell power generation system and method coupled with methanol synthesis. Background Technology
[0002] Methanol is one of the most important basic chemical raw materials, serving as a core precursor for the synthesis of hundreds of chemical products such as formaldehyde, acetic acid, and olefins. It is also a key medium for achieving a clean energy transition. Methanol can be produced from various raw materials, including coal, natural gas, and biomass, with a wide range of sources and no geographical limitations. Especially in China's energy structure of "abundant coal, scarce oil, and limited gas," coal-to-methanol technology has formed a large-scale industrial chain with an annual production capacity exceeding 90 million tons, accounting for more than 60% of global production. Furthermore, as a liquid fuel, methanol is convenient to store and transport, has a high hydrogen content, and emits significantly fewer pollutants after combustion than traditional fossil fuels. It can also be synthesized into "liquid solar methanol" through renewable energy source electrolysis of water to produce hydrogen and then synthesizing CO2, achieving carbon resource recycling and becoming an important carrier of the hydrogen economy. Currently, the application of methanol in transportation, shipping, and distributed energy is rapidly expanding. In the shipping sector, methanol-powered orders have surpassed those for natural gas fuel, highlighting its strategic value as a green energy source.
[0003] In the methanol synthesis process, purge gas is the actively emitted recirculated tail gas used to maintain the stable operation of the reaction system. Its typical composition includes hydrogen (40%-60%), carbon monoxide (5%-15%), carbon dioxide (5%-10%), methane (10%-30%), and small amounts of inert gases such as nitrogen and argon, while also carrying trace amounts of methanol vapor. Traditional treatment methods include direct combustion for energy or separation and purification of hydrogen / carbon monoxide. However, the former has low energy efficiency, and the latter cannot fully utilize the mixed gas, and both involve high equipment investment and operating costs, resulting in a lengthy process and increased energy consumption.
[0004] Therefore, there is an urgent need for an efficient and intensive technology for the resource utilization of purge gas. Summary of the Invention
[0005] In view of this, the technical problem to be solved by the present invention is to provide a high-temperature solid oxide fuel cell power generation system and method coupled with methanol synthesis, thereby realizing the resource utilization of purge gas.
[0006] To achieve the above objectives, the present invention provides a high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis, comprising a methanol synthesis reaction system and an SOFC power generation system;
[0007] The methanol synthesis reaction system includes a methanol synthesis reactor; the SOFC power generation system includes a reforming reactor and an SOFC stack.
[0008] The methanol synthesis reactor is a tubular reactor, with a methanol synthesis catalyst installed in the tube side to carry out the methanol synthesis reaction.
[0009] The shell side of the tubular reactor is equipped with water and synthetic methanol purge gas; the methanol synthesis reaction is exothermic, causing the water and synthetic methanol purge gas in the shell side to vaporize and heat up.
[0010] The vaporized and heated water and the synthetic methanol purge gas enter the reforming reactor to carry out the reforming reaction and generate electrochemical reaction feed gas, which then enters the SOFC stack for electrochemical reaction.
[0011] Optionally, the methanol synthesis reaction system further includes a gas-liquid separator;
[0012] The material obtained from the methanol synthesis reaction enters the gas-liquid separator, where it is separated to obtain the synthetic methanol purge gas, which is then returned to the shell side of the tubular reactor.
[0013] Optionally, the methanol synthesis reaction system includes a first heat exchanger, a methanol synthesis reactor, a cooler, and a gas-liquid separator;
[0014] The first heat exchanger is provided with a first air inlet, a second air inlet, and a first air outlet;
[0015] The first air inlet is used for the introduction of syngas feedstock; the first air outlet is connected to the air inlet of the methanol synthesis reactor, and is used for the syngas feedstock after heat exchange to enter the tube side of the methanol synthesis reactor for reaction;
[0016] The methanol synthesis reactor is connected in sequence to a cooler and a gas-liquid separator. After the methanol synthesis reaction is completed, the material enters the cooler to cool down, and then enters the gas-liquid separator to separate the methanol synthesis circulating gas, methanol synthesis purge gas, and liquid phase. The methanol synthesis circulating gas enters the first heat exchanger through the second inlet of the first heat exchanger, and the methanol synthesis purge gas enters the shell side of the methanol synthesis reactor. The liquid phase is crude methanol.
[0017] Optionally, the first heat exchanger is provided with a third air inlet and a second air outlet;
[0018] The outlet of the methanol synthesis reactor is connected to the third inlet of the first heat exchanger, and the second outlet of the first heat exchanger is connected to the inlet of the cooler.
[0019] After the methanol synthesis reaction is completed, the material first enters the first heat exchanger through the third inlet for initial cooling, and then enters the cooler through the second outlet for further cooling.
[0020] Optionally, the SOFC power generation system further includes a second heat exchanger;
[0021] The inlet of the second heat exchanger is connected to the outlet of the methanol synthesis reactor and is connected to the shell side of the tubular reactor; the outlet of the second heat exchanger is connected to the inlet of the reforming reactor.
[0022] Optionally, the SOFC stack includes an anode and a cathode; the anode is connected to the outlet of the reforming reactor.
[0023] Optionally, the SOFC power generation system further includes: a blower and a third heat exchanger;
[0024] The blower is provided with an air inlet, and the air outlet of the blower is connected to the air inlet of the third heat exchanger; the air outlet of the third heat exchanger is connected to the air inlet of the SOFC stack cathode.
[0025] Optionally, the SOFC stack further includes: a cathode exhaust gas outlet and an anode exhaust gas outlet, which are connected to the burner.
[0026] The burner's outlet is connected in sequence to the reforming reactor, the second heat exchanger, and the third heat exchanger.
[0027] The present invention also provides a method for generating electricity using a high-temperature solid oxide fuel cell coupled with methanol synthesis, comprising the following steps:
[0028] Provide a high-temperature solid oxide fuel cell power generation system coupled with the above-mentioned methanol synthesis;
[0029] Synthesis gas is introduced into the tubular section of the methanol synthesis reactor through the inlet. Under the catalytic action of the methanol synthesis catalyst, the methanol synthesis reaction takes place. The generated material is cooled and then enters the gas-liquid separator, where crude methanol and synthetic methanol purge gas are obtained through separation.
[0030] The purge gas from the methanol synthesis reactor enters the shell side of the methanol synthesis reactor, mixes with water, and is heated by the heat released during the methanol synthesis reaction, causing vaporization and temperature rise.
[0031] The vaporized and heated water and the synthetic methanol purge gas enter the reforming reactor to carry out the reforming reaction and generate electrochemical reaction feed gas, which then enters the SOFC stack for electrochemical reaction.
[0032] Optionally, the synthesis gas is heated by a heat exchanger before entering the tube side of the methanol synthesis reactor.
[0033] The material generated by the methanol synthesis reaction first enters the shell side of the first heat exchanger to heat the synthesis gas as a heat source. At the same time, the material is cooled for the first time through heat exchange, and then enters the cooler for further cooling.
[0034] The gas-liquid separator also separates unreacted syngas, which is returned to the first heat exchanger for reuse in the system, or connected to the SOFC stack as a raw material for electrochemical reaction.
[0035] Compared with the prior art, the present invention provides a high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis, including a methanol synthesis reaction system and an SOFC power generation system; wherein, the methanol synthesis reaction system includes a methanol synthesis reactor; the SOFC power generation system includes a reforming reactor and an SOFC stack; the methanol synthesis reactor is a tubular reactor, with a methanol synthesis catalyst installed in the tube side and water and methanol synthesis purge gas installed in the shell side; the shell side of the tubular reactor is connected to the SOFC power generation system.
[0036] The present invention achieves the following beneficial effects:
[0037] 1. This invention provides an efficient way to utilize purge gas during methanol synthesis. By combining it with a solid oxide fuel cell, a high proportion of H2, CO and CH4 are directly used as SOFC fuel and converted into electrical energy through an electrochemical reaction. This avoids the thermodynamic losses and pollutant emissions in the traditional combustion process. The generated electrical energy can be used in power equipment such as blowers, pumps and compressors in the methanol synthesis system.
[0038] 2. The high-temperature characteristics of SOFC can simultaneously utilize CO2 and residual methanol vapor in the purge gas, and further improve fuel utilization through internal reforming reaction. For example, CO2 can react with H2 to produce methane, while methanol vapor can directly participate in electrochemical reaction. Therefore, according to market demand, one or more of syngas, synthetic methanol purge gas and methanol can be flexibly controlled as raw materials for SOFC power generation system, with broad application prospects and the ability to achieve flexible adjustment of power-methanol, etc.
[0039] 3. Compared with traditional purge gas treatment processes, SOFC systems do not require multi-stage reactors and complex gas separation devices, significantly reducing equipment investment and operation and maintenance costs. At the same time, they can achieve combined heat and power, further optimizing the energy cycle system. Attached Figure Description
[0040] Figure 1 A schematic diagram of the high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis provided by the present invention;
[0041] Figure 2 This is a schematic diagram of the high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis in Example 1;
[0042] Figure 3 This is a schematic diagram of the high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis in Example 2;
[0043] Figure 4 This is a schematic diagram of the high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis in Example 3. Detailed Implementation
[0044] This invention provides a high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis, comprising a methanol synthesis reaction system and an SOFC power generation system;
[0045] The methanol synthesis reaction system includes a methanol synthesis reactor; the SOFC power generation system includes a reforming reactor and an SOFC stack.
[0046] The methanol synthesis reactor is a tubular reactor, with a methanol synthesis catalyst installed in the tube side to carry out the methanol synthesis reaction.
[0047] The shell side of the tubular reactor is equipped with water and synthetic methanol purge gas; the methanol synthesis reaction is exothermic, causing the water and synthetic methanol purge gas in the shell side to vaporize and heat up.
[0048] The vaporized and heated water and the synthetic methanol purge gas enter the reforming reactor to carry out the reforming reaction and generate electrochemical reaction feed gas, which then enters the SOFC stack for electrochemical reaction.
[0049] Figure 1 This is a schematic diagram of the high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis provided by the present invention. A: Synthesis gas; B: Pure water; C: Crude methanol; D: Synthesis methanol purge gas; F: Air; I: Combustion flue gas.
[0050] In this invention, the methanol synthesis reactor is a tubular reactor. The flow path of fluid within the heat transfer tubes inside the heat exchanger is referred to as the tube side, and the flow path of fluid within the gap between the heat exchanger shell and the tube bundle is referred to as the shell side. The tube side may include multiple heat exchange tubes.
[0051] Synthesis gas A enters the methanol synthesis reaction system to react and produce crude methanol C. Synthesis methanol purge gas D and pure water B are heated in the shell side of the methanol synthesis reaction system and then enter the SOFC (solid oxide fuel cell) power generation system to produce electricity through an electrochemical reaction.
[0052] In some specific implementations, the tubular reactor is provided with an inlet that is connected to the shell side for water to enter.
[0053] In some specific implementations, the methanol synthesis reaction system further includes a gas-water separator.
[0054] The gas-liquid separator is used to separate the gas and liquid phases in the reaction products.
[0055] The materials obtained from the methanol synthesis reaction enter a gas-liquid separator, where they are separated to obtain methanol purge gas, unreacted synthesis gas feedstock gas, and liquid phase.
[0056] In this process, the methanol purge gas is returned to the shell side of the tubular reactor and mixed with pure water. Unreacted syngas feedstock gas can be returned to the reaction system. The liquid phase is the crude methanol product obtained from the reaction.
[0057] In some specific implementations, the methanol synthesis reaction system includes a first heat exchanger, a methanol synthesis reactor, a cooler, and a gas-liquid separator.
[0058] The first heat exchanger is used to heat the synthesis gas feedstock gas, optionally heating it to 200~400℃ before it enters the methanol synthesis reactor.
[0059] The first heat exchanger is provided with a first air inlet, a second air inlet, and a first air outlet;
[0060] The first inlet is used for the introduction of syngas feedstock; the first outlet is connected to the inlet of the methanol synthesis reactor and is used for the syngas feedstock after heat exchange to enter the tube side of the methanol synthesis reactor for reaction.
[0061] The methanol synthesis reactor is connected in sequence to a cooler and a gas-liquid separator. After the methanol synthesis reaction is completed, the material enters the cooler to cool down, and then enters the gas-liquid separator to separate the synthetic methanol circulating gas, synthetic methanol purge gas, and liquid phase.
[0062] In this process, the methanol synthesis gas recirculation gas enters the first heat exchanger through the second inlet and is then reused in the methanol synthesis reactor, improving the utilization rate of the synthesis gas feedstock. The methanol synthesis purge gas enters the shell side of the methanol synthesis reactor, mixes with pure water, and is heated by the heat released during the methanol synthesis reaction, which is then used in the SOFC power generation system. The liquid phase is crude methanol.
[0063] In some specific embodiments, the first heat exchanger is further provided with a third air inlet and a second air outlet. The first heat exchanger includes tubes and a shell side that surrounds the tubes. The third air inlet and the second air outlet are in communication with the shell side.
[0064] The outlet of the methanol synthesis reactor is connected to the third inlet of the first heat exchanger, and the second outlet of the first heat exchanger is connected to the inlet of the cooler.
[0065] After the methanol synthesis reaction is completed, the material first enters the shell side of the first heat exchanger through the third inlet for the first cooling. After entering the first heat exchanger, the material can be used as a heat source to heat the synthesis gas feedstock entering the inner tube through the first inlet. Thus, heat exchange is completed between the methanol synthesis reaction material and the synthesis gas feedstock, achieving the effect of heat exchange.
[0066] After the material undergoes the first cooling process described above, it enters the cooler through the second air outlet to further cool down. In some specific implementation schemes, it can be cooled to about 40°C before entering the gas-liquid separator.
[0067] The synthetic methanol purge gas separated by the gas-water separator enters the shell side of the methanol synthesis reactor, mixes with pure water, and is then heated and vaporized by the heat released during the methanol synthesis reaction before entering the SOFC power generation system.
[0068] In some specific embodiments, the SOFC power generation system further includes a second heat exchanger for heating the synthetic methanol purge gas. The inlet of the second heat exchanger is connected to the outlet of the methanol synthesis reactor, which is connected to the shell side of the tubular reactor, for discharging the heated and vaporized synthetic methanol purge gas. The outlet of the second heat exchanger is also connected to the inlet of the reforming reactor.
[0069] After the synthetic methanol purge gas enters the reforming reactor, the methanol, methane and other substances therein undergo steam reforming to produce CO, CO2 and hydrogen, which can be used as feed gas for electrochemical reactions.
[0070] SOFC stacks include an anode and a cathode. The anode is connected to the outlet of the reforming reactor. The products of the reforming reaction enter the anode, and air enters the cathode. Methanol purge gas and air undergo an electrochemical reaction in the SOFC stack to output electricity.
[0071] In some specific implementations, the SOFC power generation system further includes a blower and a third heat exchanger. The blower is provided with an air inlet for air to enter and pressurize. The air outlet of the blower is connected to the air inlet of the third heat exchanger. After entering the third heat exchanger, the air is heated, optionally to 600~700°C. The air outlet of the third heat exchanger is connected to the air inlet of the SOFC stack cathode.
[0072] In some specific implementations, the SOFC stack also includes a cathode exhaust gas outlet and an anode exhaust gas outlet, which are connected to the burner. After entering the burner, the cathode exhaust gas and anode exhaust gas undergo a combustion reaction to generate high-temperature combustion flue gas. After being cooled, the high-temperature combustion flue gas is vented at a high-point safety location.
[0073] In some specific implementation schemes, the burner's outlet is connected in sequence to the reforming reactor, the second heat exchanger, and the third heat exchanger, serving as a heat source for heating the reforming reaction, the methanol synthesis off-gas, and the air, while simultaneously cooling the cathode and anode tail gases, thus utilizing energy more efficiently.
[0074] In some specific implementations, syngas and methanol purge gas are used as raw materials for electrochemical reaction. Based on this, in addition to the aforementioned high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis, a connection is added between the syngas and the combustion flue gas-fuel side heat exchanger 8. Specifically, the outlet of the syngas is connected to the inlet of the second heat exchanger. The syngas and methanol purge gas enter the second heat exchanger together, are heated, and then enter the reforming reactor, and then enter the SOFC stack for electrochemical reaction.
[0075] In some specific implementation schemes, the unreacted syngas feedstock obtained from the gas-liquid separator can also be returned to the inlet of the second heat exchanger, and together with the methanol purge gas, it enters the second heat exchanger for heating and then enters the reforming reactor, and then enters the SOFC stack for electrochemical reaction, serving as the feedstock for the SOFC power generation system, further reducing energy consumption.
[0076] In some specific implementation schemes, methanol and methanol purge gas are used as raw materials for electrochemical reaction. Based on this, in addition to the aforementioned high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis, a connection is added between crude methanol and the combustion flue gas-fuel side heat exchanger 8. Specifically, the crude methanol obtained from the gas-liquid separator is connected to the inlet of the second heat exchanger. The crude methanol and methanol purge gas enter the second heat exchanger together, are heated, and then enter the reforming reactor, and then enter the SOFC stack for electrochemical reaction.
[0077] The present invention also provides a method for generating electricity using a high-temperature solid oxide fuel cell coupled with methanol synthesis, comprising the following steps:
[0078] Provide a high-temperature solid oxide fuel cell power generation system coupled with the above-mentioned methanol synthesis;
[0079] Synthesis gas is introduced into the tubular section of the methanol synthesis reactor through the inlet. Under the catalytic action of the methanol synthesis catalyst, the methanol synthesis reaction takes place. The generated material is cooled and then enters the gas-liquid separator, where crude methanol and synthetic methanol purge gas are obtained through separation.
[0080] The purge gas from the methanol synthesis reactor enters the shell side of the methanol synthesis reactor, mixes with water, and is heated by the heat released during the methanol synthesis reaction, causing vaporization and temperature rise.
[0081] The vaporized and heated water and the synthetic methanol purge gas enter the reforming reactor to carry out the reforming reaction and generate electrochemical reaction feed gas, which then enters the SOFC stack for electrochemical reaction.
[0082] The composition of the synthesis gas is not particularly limited in this invention. It can be any gas mixture known to those skilled in the art that is suitable for methanol synthesis reaction, preferably a synthesis gas with a hydrogen to carbon monoxide ratio of 2 to 3:1.
[0083] Preferably, the synthesis gas is heated by a heat exchanger before entering the tube side of the methanol synthesis reactor. The preferred temperature is 200-400°C.
[0084] Preferably, the material generated from the methanol synthesis reaction is cooled in a cooler.
[0085] Preferably, the material generated by the methanol synthesis reaction first enters the shell side of the first heat exchanger to heat the synthesis gas as a heat source, and at the same time, the material is cooled for the first time through heat exchange, and then enters the cooler for further cooling.
[0086] Preferably, the mixture is cooled to 30~50°C, more preferably to 40±2°C, before entering the gas-liquid separator.
[0087] In some specific embodiments, the gas-liquid separator also separates unreacted syngas, which can be returned to the first heat exchanger for reuse in the system, or connected to the SOFC stack as a raw material for electrochemical reactions.
[0088] In some specific embodiments, the crude methanol obtained by the gas-liquid separator is connected to the SOFC stack and used as a raw material for electrochemical reaction.
[0089] Preferably, the vaporized and heated water and the synthetic methanol purge gas are heated by heat exchange in a second heat exchanger before entering the reforming reactor. The reforming products enter the anode of the SOFC stack, while air enters the cathode. The methanol purge gas and air undergo an electrochemical reaction in the SOFC stack to generate electricity. Preferably, the air is pressurized by a blower, then heated by a third heat exchanger before entering the cathode. The temperature is preferably raised to 600-700°C.
[0090] The exhaust gases generated at the cathode and anode enter the burner and undergo a combustion reaction to produce high-temperature combustion flue gas.
[0091] The aforementioned high-temperature combustion flue gas needs to be cooled before being emitted. Preferably, the high-temperature combustion flue gas sequentially enters a reforming reactor, a second heat exchanger, and a third heat exchanger to serve as a heat source for heat exchange.
[0092] Solid oxide fuel cells (SOFCs), as a third-generation fuel cell, have become a key direction in the energy technology revolution due to their all-solid-state structure, wide fuel adaptability, and high energy conversion efficiency (60%-85%). Their core advantages are: 1) They can directly utilize various carbon-based fuels such as hydrogen, CO, and methane without requiring precious metal catalysts and are resistant to impurities such as sulfides, reducing fuel pretreatment costs; 2) High-temperature operation (600-1000℃) promotes internal fuel reforming, simplifies system design, and the high-grade waste heat generated can achieve combined heat and power (CHP), resulting in a comprehensive energy utilization rate exceeding 80%; 3) Modular design flexibly adapts to distributed power generation scenarios, combining environmental friendliness and economic efficiency.
[0093] This invention innovatively uses methanol synthesis off-gas as SOFC fuel, effectively combining the advantages of solid oxide fuel cells, such as low requirements for raw materials and the ability to "eat various grains", to achieve the dual benefit of "improving efficiency with waste". It not only opens up new avenues for the high-value utilization of chemical by-product gas, but also provides innovative solutions for clean energy system integration and carbon emission reduction.
[0094] To further illustrate the present invention, a detailed description is provided below with reference to embodiments. However, it should be understood that these descriptions are merely for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims.
[0095] There are no particular restrictions on the source of any raw materials used in this invention; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.
[0096] Example 1
[0097] use Figure 2 The high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis is shown, wherein,
[0098] 1-Synthesis gas feedstock heat exchanger (first heat exchanger); 2-Methanol synthesis reactor; 3-Synthetic methanol cooler; 4-Gas-water separator; 5-Blower; 6-Combustion flue gas-air heat exchanger (third heat exchanger); 7-SOFC stack; 8-Combustion flue gas-fuel side heat exchanger (second heat exchanger); 9-Reform reactor; 10-SOFC tail gas burner.
[0099] A - Synthesis gas; B - Pure water; C - Crude methanol; D - Synthesis methanol purge gas; E - Synthesis methanol recycle gas; F - Air; G - Anode tail gas; H - Cathode tail gas; I - Combustion flue gas.
[0100] Syngas A enters syngas feedstock heat exchanger 1, where it exchanges heat with the outlet stream of methanol synthesis reactor 2, raising its temperature to 200-400°C before entering methanol synthesis reactor 2. Methanol synthesis reactor 2 is a tubular reactor; the tube side is filled with methanol synthesis catalyst, and the shell side is a mixture of pure water B and synthetic methanol purge gas D, which is the fuel-side stream for SOFC power generation. The heat released during methanol synthesis is used for the vaporization and heating of pure water B and methanol purge gas. The outlet product of methanol synthesis reactor 2 exchanges heat with syngas A for cooling, then enters synthetic methanol cooler 3, where it exchanges heat with cooling water to be cooled to approximately 40°C before entering gas-liquid separator 4. The gas phase is split into two streams: synthetic methanol recycle gas E and synthetic methanol purge gas D. Synthetic methanol recycle gas E mixes with syngas A and enters methanol synthesis reactor 2 to synthesize methanol, improving the utilization rate of syngas feedstock. Synthetic methanol purge gas D is used in the SOFC power generation system. The liquid phase is crude methanol C.
[0101] A mixture of methanol purge gas D and pure water B enters methanol synthesis reactor 2 for heat exchange and heating, then enters combustion flue gas-fuel side heat exchanger 8 for further heat exchange and heating, and then enters reforming reactor 9. Methanol, methane, and other components in methanol purge gas D undergo steam reforming to produce CO, CO2, and hydrogen. The reformed products enter the anode of SOFC stack 7. Air F enters blower 5 for pressurization and then enters combustion flue gas-air heat exchanger 6 to exchange heat with combustion flue gas, heating it to 600-700°C before entering the cathode of SOFC stack 7. Methanol purge gas and air undergo an electrochemical reaction in the SOFC stack to output electricity. Anode tail gas G and cathode tail gas H enter burner 10, where a combustion reaction occurs to generate high-temperature combustion flue gas I. High-temperature combustion flue gas I sequentially exchanges heat with reforming reactor 9, combustion flue gas-fuel side heat exchanger 8, and combustion flue gas-air heat exchanger 6, cooling it to approximately 100°C before being safely vented at a high point.
[0102] Analysis results show that 1 ton of syngas, with a 95% recycling conversion rate, can produce 830-850 kg of methanol, and the purge gas release is approximately 290-300 Nm³. 3 When applied to SOFC power generation systems, it can generate 660~680kW of electricity.
[0103] Example 2
[0104] use Figure 3 The high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis shown is... Figure 2 The only difference is the addition of a connection between the syngas and the combustion flue gas-fuel side heat exchanger 8, which uses syngas and methanol off-gas as raw materials for electrochemical reaction.
[0105] This embodiment adds the direct use of syngas as raw material for SOFC power generation. 1 ton of syngas with a typical composition can generate approximately 3300 kWh of electricity.
[0106] Example 3
[0107] use Figure 4 The high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis shown is... Figure 2 The only difference is the addition of a connection between crude methanol and the combustion flue gas-fuel side heat exchanger 8, which uses methanol and methanol off-gas as raw materials for an electrochemical reaction.
[0108] This embodiment adds the feature of directly generating SOFC power from the generated crude methanol, with 1 ton of crude methanol generating approximately 3000 kWh of electricity.
[0109] The above embodiments describe cases of using purge gas, a portion of syngas, and a portion of crude methanol products in SOFC power generation systems. In actual implementation, the purge gas can be flexibly adjusted to regulate the proportion of syngas used to generate methanol, thereby achieving flexible conversion between syngas, methanol, and electricity.
[0110] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.
Claims
1. A high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis, comprising a methanol synthesis reaction system and an SOFC power generation system; in, The methanol synthesis reaction system includes a methanol synthesis reactor; the SOFC power generation system includes a reforming reactor and an SOFC stack. The methanol synthesis reactor is a tubular reactor, with a methanol synthesis catalyst installed in the tube side to carry out the methanol synthesis reaction. The shell side of the tubular reactor is equipped with water and synthetic methanol purge gas; the methanol synthesis reaction is exothermic, causing the water and synthetic methanol purge gas in the shell side to vaporize and heat up. The vaporized and heated water and the synthetic methanol purge gas enter the reforming reactor to carry out the reforming reaction and generate electrochemical reaction feed gas, which then enters the SOFC stack for electrochemical reaction.
2. The high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis according to claim 1, characterized in that, The methanol synthesis reaction system also includes a gas-liquid separator; The material obtained from the methanol synthesis reaction enters the gas-liquid separator, where it is separated to obtain the synthetic methanol purge gas, which is then returned to the shell side of the tubular reactor.
3. The high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis according to claim 2, characterized in that, The methanol synthesis reaction system includes a first heat exchanger, a methanol synthesis reactor, a cooler, and a gas-liquid separator; The first heat exchanger is provided with a first air inlet, a second air inlet, and a first air outlet; The first air inlet is used for the introduction of syngas feedstock; the first air outlet is connected to the air inlet of the methanol synthesis reactor, and is used for the syngas feedstock after heat exchange to enter the tube side of the methanol synthesis reactor for reaction; The methanol synthesis reactor is connected in sequence to a cooler and a gas-liquid separator. After the methanol synthesis reaction is completed, the material enters the cooler to cool down, and then enters the gas-liquid separator to separate the methanol synthesis circulating gas, methanol synthesis purge gas, and liquid phase. The methanol synthesis circulating gas enters the first heat exchanger through the second inlet of the first heat exchanger, and the methanol synthesis purge gas enters the shell side of the methanol synthesis reactor. The liquid phase is crude methanol.
4. The high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis according to claim 3, characterized in that, The first heat exchanger is provided with a third air inlet and a second air outlet; The outlet of the methanol synthesis reactor is connected to the third inlet of the first heat exchanger, and the second outlet of the first heat exchanger is connected to the inlet of the cooler. After the methanol synthesis reaction is completed, the material first enters the first heat exchanger through the third inlet for initial cooling, and then enters the cooler through the second outlet for further cooling.
5. The high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis according to claim 1, characterized in that, The SOFC power generation system also includes a second heat exchanger; The inlet of the second heat exchanger is connected to the outlet of the methanol synthesis reactor and is connected to the shell side of the tubular reactor; the outlet of the second heat exchanger is connected to the inlet of the reforming reactor.
6. The high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis according to claim 1, characterized in that, The SOFC stack includes an anode and a cathode; the anode is connected to the outlet of the reforming reactor.
7. The high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis according to claim 6, characterized in that, The SOFC power generation system also includes: a blower and a third heat exchanger; The blower is provided with an air inlet, and the air outlet of the blower is connected to the air inlet of the third heat exchanger; the air outlet of the third heat exchanger is connected to the air inlet of the SOFC stack cathode.
8. The high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis according to claim 1, characterized in that, The SOFC stack also includes: a cathode exhaust gas outlet and an anode exhaust gas outlet, which are connected to the burner. The burner's outlet is connected in sequence to the reforming reactor, the second heat exchanger, and the third heat exchanger.
9. A method for generating electricity using a high-temperature solid oxide fuel cell coupled with methanol synthesis, comprising the following steps: Provide a high-temperature solid oxide fuel cell power generation system coupled with methanol synthesis as described in any one of claims 1 to 8; Synthesis gas is introduced into the tubular section of the methanol synthesis reactor through the inlet. Under the catalytic action of the methanol synthesis catalyst, the methanol synthesis reaction takes place. The generated material is cooled and then enters the gas-liquid separator, where crude methanol and synthetic methanol purge gas are obtained through separation. The purge gas from the methanol synthesis reactor enters the shell side of the methanol synthesis reactor, mixes with water, and is heated by the heat released during the methanol synthesis reaction, causing vaporization and temperature rise. The vaporized and heated water and the synthetic methanol purge gas enter the reforming reactor to carry out the reforming reaction and generate electrochemical reaction feed gas, which then enters the SOFC stack for electrochemical reaction.
10. The method for generating electricity using a high-temperature solid oxide fuel cell coupled with methanol synthesis according to claim 9, characterized in that, The synthesis gas is heated by a heat exchanger and then enters the tube side of the methanol synthesis reactor. The material generated by the methanol synthesis reaction first enters the shell side of the first heat exchanger to heat the synthesis gas as a heat source. At the same time, the material is cooled for the first time through heat exchange, and then enters the cooler for further cooling. The gas-liquid separator also separates unreacted syngas, which is returned to the first heat exchanger for reuse in the system, or connected to the SOFC stack as a raw material for electrochemical reaction.