Rectification dehydrogenation and fuel cell combined coupling system

Abstract

The utility model relates to a rectification dehydrogenation and fuel cell combined coupling system, which comprises a rectification dehydrogenation system, a fuel cell system, a mixer and a combustion chamber, the rectification dehydrogenation system comprises a reactive distillation tower and a reboiler I, the reboiler I is communicated with the tower bottom of the reactive distillation tower, the fuel cell system comprises an SOFC (Solid Oxide Fuel Cell) electric pile, and the fuel cell system comprises a fuel cell. The SOFC electric pile comprises an anode and a cathode, an anode waste gas outlet of the SOFC electric pile is communicated with the mixer, a cathode waste gas outlet of the SOFC electric pile is communicated with the mixer, the mixer is communicated with the combustion chamber, and combustion tail gas of the combustion chamber is communicated with the outside of the first reboiler and is used for providing a heating heat source for the first reboiler. The high-efficiency power generation efficiency of the system is realized, and meanwhile, the carbon emission and the consumed economic cost of the system are effectively reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of energy technology especially relates to a rectification dehydrogenation and fuel cell combined coupling system. BACKGROUND

[0002] In order to cope with the dual challenge of energy crisis and environmental pollution, distributed energy system (DES) arouses the extensive attention of researchers because of its small scale deployment, modularity, high efficiency and stability. Among them, solid oxide fuel cell (SOFC) as an advanced power generation equipment, with its power generation high efficiency, simple structure, good fuel adaptation, environmental friendly characteristics, becomes one of the most promising power generation technologies. The working temperature range of SOFC is 650-1000 DEG C, and a large amount of high-grade waste heat is generated in the power generation process, in order to recover this part of heat energy, combining SOFC with upstream fuel production process (such as dehydrogenation process of liquid organic hydrogen carrier (LOHC)) is an effective means to improve energy efficiency. Liquid organic hydrogen carrier technology is a promising hydrogen storage and transportation method, which can realize long-distance efficient transportation of hydrogen by using existing oil and gas infrastructure. However, the high energy consumption accompanied by LOHC dehydrogenation process is still a technical problem that needs to be overcome in the process of wide application of the technology.

[0003] At present, scholars have carried out relevant research on the integration of SOFC and LOHC system, mainly the combination of SOFC and fixed bed dehydrogenation process, the anode tail gas generated by SOFC is used to preheat hydrogen, the cathode tail gas is used to preheat air, and then the mixed combustion is carried out, and the tail gas after combustion is directly used as the heating source of the fixed bed reaction section. In this process, in order to avoid that the temperature of the reaction section of the fixed bed reactor is too high, fresh air is used to reduce the temperature of the tail gas after combustion, and the dehydrogenation temperature of the fixed bed dehydrogenation process is high, and the energy consumption is large. Although the combination of SOFC and fixed bed dehydrogenation process can reduce the energy consumption of the system to a certain extent, the use of fresh air to reduce the temperature of the tail gas after combustion reduces the energy grade of the tail gas. Therefore, how to further reduce the energy consumption of the process and realize the maximum utilization of SOFC tail gas energy becomes an important problem.

[0004] Therefore, the prior art still needs to be improved and developed. UTILITY MODEL CONTENT

[0005] In view of the above problems of the prior art, the utility model aims at providing a rectification dehydrogenation and fuel cell combined coupling system, which aims at solving the problem of high energy consumption generated in the dehydrogenation process and realizing the maximum utilization of SOFC tail gas energy.

[0006] The utility model system realizes efficient system power generation efficiency, effectively reduces system carbon emission and economic cost.

[0007] The technical scheme of the utility model discloses as follows:

[0008] Scheme one)

[0009] A kind of rectification dehydrogenation and fuel cell coupling coupling system, including rectification dehydrogenation system, fuel cell system, mixer, combustion chamber,

[0010] The rectification dehydrogenation system includes reaction rectifying tower, reboiler one,

[0011] The fuel cell system includes SOFC electric pile, the SOFC electric pile includes anode and cathode, the anode exhaust outlet of the SOFC electric pile is communicated with the mixer, the cathode exhaust outlet of the SOFC electric pile is communicated with the mixer, the mixer is communicated with combustion chamber,

[0012] The combustion tail gas of the combustion chamber is communicated with the reboiler one for providing the heating heat source of reboiler one, the reboiler one is communicated with the bottom of the reaction rectifying tower.

[0013] Further, in order to more reasonable energy utilization: the fuel cell system further includes hydrogen preheater one, the hydrogen preheater one is connected between the anode exhaust outlet of the SOFC electric pile and the mixer and is located before SOFC electric pile anode gas inlet for preheating hydrogen into anode;

[0014] Or the hydrogen preheater one is connected between the combustion chamber and reboiler one and is located before SOFC electric pile anode gas inlet for preheating hydrogen into anode.

[0015] Further, in order to more reasonable energy utilization: the fuel cell system further includes air preheater one, the air preheater one is connected between the cathode exhaust outlet of the SOFC electric pile and the mixer and is located before SOFC electric pile cathode gas inlet for preheating air into cathode;

[0016] Or the air preheater one is connected between the reboiler one and SOFC electric pile cathode gas inlet and is located before SOFC electric pile cathode gas inlet for preheating air into cathode;

[0017] Or the air preheater one is connected between the anode exhaust outlet of the SOFC electric pile and mixer and is located before SOFC electric pile cathode gas inlet for preheating air into cathode;

[0018] Or the air preheater one is connected between the combustion chamber and reboiler one and is located before cathode gas inlet for preheating air into cathode.

[0019] Further, to ensure the stable operation of the fuel cell system to meet the process requirements, the fuel cell system further comprises a hydrogen preheater two arranged between the hydrogen preheater one and the anode, and an air preheater two arranged between the air preheater one and the cathode.

[0020] Further, the overhead hydrogen stream outlet of the reaction rectification tower is in communication with the anode of the SOFC stack, and a condenser and a pressure relief valve are arranged between the overhead hydrogen stream outlet of the reaction rectification tower and the anode of the SOFC stack.

[0021] Further, to meet the process requirements, the reboiler one is further in communication with the bottom of the reaction rectification tower and is provided with a reboiler two.

[0022] Further, to make the energy utilization more reasonable, the fuel cell system is further provided with a GT turbine and a generator, and the combustion tail gas of the combustion chamber is communicated with the GT turbine for providing power for GT turbine power generation.

[0023] Beneficial effects: The rectification dehydrogenation and fuel cell coupling system of the utility model realizes high-efficiency system power generation efficiency, effectively reduces system carbon emission and economic cost. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is the structure schematic view of the rectification dehydrogenation and fuel cell coupling system of example 1.

[0025] Figure 2 is the structure schematic view of the rectification dehydrogenation and fuel cell coupling system of example 2.

[0026] Figure 3 is the structure schematic view of the rectification dehydrogenation and fuel cell coupling system of example 3.

[0027] Figure 4 is the structure schematic view of the rectification dehydrogenation and fuel cell coupling system of example 4.

[0028] In the drawing:

[0029] 1, hydrogen-rich storage tank; 2, reaction rectification tower; 3, condenser; 4, pressure relief valve; 5, hydrogen preheater one; 6, hydrogen preheater two; 7, SOFC stack; 8, air preheater one; 9, air preheater two; 10, mixer; 11, combustion chamber; 12, reboiler one; 13, reboiler two; 14, hydrogen-poor storage tank; 15, pre-reactor; 16, back-pack reactor; 19, turbine; 20, generator. DETAILED DESCRIPTION

[0030] The utility model provides a kind of rectification dehydrogenation and fuel cell coupling system and coupling method thereof, to make the purpose, technical scheme and effect of the utility model more clear, the following is further detailed to the utility model of the utility model.It should be understood that the specific embodiments described herein are merely intended to explain the utility model and not to limit the utility model.

[0031] As Figure 1 The utility model provides a kind of rectification dehydrogenation and fuel cell coupling system, including rectification dehydrogenation system, fuel cell system, mixer 10, combustion chamber 11.

[0032] The rectification dehydrogenation system includes reaction rectification tower 2, reboiler one 12, the reboiler one 12 is communicated with the reaction rectification tower 2 bottom.

[0033] The fuel cell system includes SOFC electric pile 7, the SOFC electric pile 7 includes anode and cathode, the SOFC electric pile 7 anode exhaust outlet is communicated with the mixer 10, the SOFC electric pile 7 cathode exhaust outlet is communicated with the mixer 10, and the mixer 10 is communicated with combustion chamber 11.

[0034] The combustion tail gas of the combustion chamber 11 is communicated with the reboiler one 12, to provide the heating heat source of reboiler one 12.

[0035] SOFC electric pile 7 anode exhaust gas and SOFC electric pile 7 cathode exhaust gas are mixed by mixer 10, then mixed gas is combusted in combustion chamber 11, and the tail gas of combustion chamber combustion is communicated with reboiler one 12, can be used to heat reboiler one 12, to save energy.

[0036] When using, dehydrogenation raw material is passed into reaction rectification tower 2 and carries out reaction rectification, and the hydrogen gas taken from the reaction rectification tower 2 top is sent to SOFC electric pile 7 anode and air passed into SOFC electric pile 7 cathode reaction, SOFC electric pile 7 anode exhaust gas and SOFC electric pile 7 cathode exhaust gas are discharged after SOFC electric pile 7 reaction, then SOFC electric pile 7 anode exhaust gas and SOFC electric pile 7 cathode exhaust gas are mixed in mixer 10 first, then are combusted in combustion chamber 11, and the tail gas produced in combustion chamber 11 combustion is passed into reboiler one 12 and is used to heat reboiler one 12.

[0037] The utility model discloses in order to more reasonable energy utilization, the fuel cell system further includes hydrogen preheater one 5, the hydrogen preheater one 5 is connected between the SOFC electric pile 7 anode exhaust outlet and the mixer 10 and is located before SOFC electric pile 7 anode gas inlet for preheating hydrogen passed into anode.

[0038] The SOFC stack 7 anode exhaust gas is first preheated by the hydrogen preheater 5 before entering the SOFC stack 7 anode, and then enters the mixer 10, which can further prevent heat loss.

[0039] In one embodiment, in order to make the energy utilization more reasonable, the fuel cell system further comprises an air preheater 8 connected between the SOFC stack 7 cathode exhaust gas outlet and the mixer 10 and located before the SOFC stack 7 cathode gas inlet for preheating the air entering the cathode.

[0040] The SOFC stack 7 cathode exhaust gas is first preheated by the air preheater 8 before entering the SOFC stack 7 cathode, and then enters the mixer 10, which can further prevent heat loss.

[0041] Specifically, in order to ensure the stable operation of the fuel cell system to meet the process requirements, the fuel cell system further comprises a hydrogen preheater 6 arranged between the hydrogen preheater 5 and the anode, and an air preheater 9 arranged between the air preheater 8 and the cathode.

[0042] The hydrogen preheater 6 and the air preheater 9 can ensure the temperature of the hydrogen and air entering the SOFC stack 7 anode and the SOFC stack 7 cathode, thereby ensuring the stable operation of the system.

[0043] Specifically, the reaction rectification column 2 overhead hydrogen stream outlet is in communication with the SOFC stack 7 anode, and a condenser 3 and a pressure relief valve 4 are arranged between the reaction rectification column 2 overhead hydrogen stream outlet and the SOFC stack 7 anode.

[0044] The condenser 3 can realize gas-liquid separation of the gas taken out from the top of the reaction rectification column 2, the gas phase is hydrogen, which can be temporarily stored in the hydrogen-rich storage tank 1 as the hydrogen raw material of the fuel cell system through the pressure relief valve 4, and the liquid phase is returned to the column as a condensate to continue rectification.

[0045] Specifically, in order to meet the process requirements, the reboiler 12 is further in communication with the reboiler 13 arranged between the reaction rectification column 2 bottom.

[0046] The reboiler 13 can ensure the temperature of the material entering the reaction rectification column 2, thereby ensuring the stable operation of the system.

[0047] In one embodiment, as shown in Figure 2 The hydrogen preheater 5 is connected between the combustion chamber 11 and the reboiler 12 and located before the SOFC stack 7 anode gas inlet for preheating the hydrogen entering the anode.

[0048] The tail gas produced by the combustion of the combustion chamber 11 is first preheated by the hydrogen preheater 5 to preheat the hydrogen gas entering the anode of the SOFC stack 7, and then is preheated by the reboiler 12 to preheat the material entering the reaction rectifying tower 2.

[0049] The air preheater 8 is connected between the reboiler 12 and the cathode gas inlet of the SOFC stack 7 and is located before the cathode gas inlet of the SOFC stack 7 to preheat the air entering the cathode.

[0050] The tail gas produced by the combustion of the combustion chamber 11 is first preheated by the reboiler 12 to preheat the material entering the reaction rectifying tower 2, and then is preheated by the air preheater 8 to preheat the air entering the cathode of the SOFC stack 7.

[0051] In one embodiment, as shown in Figure 3 The hydrogen preheater 5 is connected between the reboiler 12 and the anode gas inlet of the SOFC stack 7 to preheat the hydrogen gas entering the anode.

[0052] The tail gas produced by the combustion of the combustion chamber 11 is first preheated by the reboiler 12 to preheat the material entering the reaction rectifying tower 2, and then is preheated by the air preheater 8 to preheat the air entering the cathode of the SOFC stack 7.

[0053] The air preheater 8 is connected between the anode exhaust gas outlet of the SOFC stack 7 and the mixer 10 and is located before the cathode gas inlet of the SOFC stack 7 to preheat the air entering the cathode.

[0054] The anode exhaust gas of the SOFC stack 7 is first preheated by the air preheater 8 to preheat the air entering the cathode of the SOFC stack 7, and then is preheated by the mixer 10.

[0055] In one embodiment, as shown in Figure 4 The air preheater 8 is connected between the combustion chamber 11 and the reboiler 12 and is located before the cathode gas inlet to preheat the air entering the cathode.

[0056] The tail gas produced by the combustion of the combustion chamber 11 is first preheated by the air preheater 8 to preheat the air entering the cathode of the SOFC stack 7, and then is preheated by the reboiler 12 to preheat the material entering the reaction rectifying tower 2.

[0057] In order to make the energy utilization more reasonable, the fuel cell system is further provided with a GT turbine 19 and a generator 20, and the combustion tail gas of the combustion chamber 11 is communicated with the GT turbine 19 to provide power for the power generation of the GT turbine 19.

[0058] Optionally, the raw material used in application can be H12-BT with a purity of 75%-99.9%.

[0059] In one embodiment, the operating pressure of the reactive distillation column 2 is 0.3-3 bar, the temperature of the overhead condenser 3 is 25-60℃, the reboiler ratio of the column bottom reboiler is 10-20, the reboiler temperature is 225-350℃, the number of reaction stages is 1-15, and the total number of theoretical plates is 2-25.

[0060] In one embodiment, the working temperature of the SOFC stack 7 is 700-1200℃, the gas inlet temperature of the SOFC stack 7 is 500-1000℃, the working pressure is 1-8 bar, the air excess coefficient is 1-5, the fuel utilization rate is 0.7-0.9, and the number of single cells of the SOFC stack 7 is 1000-6000.

[0061] In one embodiment, the purity of hydrogen extracted from the top of the reactive distillation column 2 is 80-99.99%, and the purity of H0-BT in the column bottom product is 50-95% with a dehydrogenation degree of 55-95%.

[0062] In one embodiment, the anode tail gas of the fuel cell system is 726.85-1126.85℃, the cathode tail gas is 726.85-1126.85℃, and the tail gas temperature discharged from the combustion chamber 11 is 400-1200℃.

[0063] Example 1

[0064] As shown in Figure 1 , the present embodiment provides a distillation dehydrogenation and fuel cell coupled system, which comprises a distillation dehydrogenation system, a fuel cell system, a mixer 10, and a combustion chamber 11.

[0065] The distillation dehydrogenation system comprises a reactive distillation column 2 and a reboiler one 12, wherein the reboiler one 12 is in communication with the bottom of the reactive distillation column 2.

[0066] The fuel cell system comprises a SOFC stack 7, wherein the SOFC stack 7 comprises an anode and a cathode, the anode exhaust gas outlet of the SOFC stack 7 is in communication with the mixer 10, the cathode exhaust gas outlet of the SOFC stack 7 is in communication with the mixer 10, and the mixer 10 is in communication with the combustion chamber 11.

[0067] The combustion tail gas of the combustion chamber 11 is communicated to the reboiler one 12 for providing a heating heat source for the reboiler one 12.

[0068] The fuel cell system further comprises a hydrogen preheater one 5, which is connected between the anode exhaust gas outlet of the SOFC stack 7 and the mixer 10 and located before the anode gas inlet of the SOFC stack 7 for preheating hydrogen entering the anode.

[0069] The fuel cell system further comprises an air preheater one 8 connected between the SOFC stack 7 cathode exhaust gas outlet and the mixer 10 and located before the SOFC stack 7 cathode air inlet for preheating the air entering the cathode.

[0070] The fuel cell system further comprises a hydrogen preheater two 6 located between the hydrogen preheater one 5 and the anode, and an air preheater two 9 located between the air preheater one 8 and the cathode.

[0071] The reaction distillation column 2 overhead hydrogen stream outlet is in communication with the SOFC stack 7 anode, and a condenser 3 and a pressure relief valve 4 are provided between the reaction distillation column 2 overhead hydrogen stream outlet and the SOFC stack 7 anode.

[0072] The reboiler one 12 is further in communication with the reaction distillation column 2 bottom, and a reboiler two 13 is provided.

[0073] The reboiler two 13 can ensure the temperature of the material entering the reaction distillation column 2, thereby ensuring the stable operation of the system.

[0074] The reaction distillation column 2 in the distillation dehydrogenation and fuel cell coupled system of the embodiment is a pressurized reaction distillation dehydrogenation column, and the fuel cell system is a normal pressure plate type SOFC coupled system.

[0075] In use, the perhydrogen benzyl toluene H12-BT is fed into the reaction distillation column 2 for reaction distillation, the hydrogen gas taken from the reaction distillation column 2 overhead is sent to the SOFC stack 7 anode to react with the air entering the SOFC stack 7 cathode, the SOFC stack 7 anode exhaust gas and the SOFC stack 7 cathode exhaust gas are discharged after the SOFC stack 7 reaction, then the SOFC stack 7 anode exhaust gas and the SOFC stack 7 cathode exhaust gas are mixed in the mixer 10 first, and then burned in the combustion chamber 11, and the tail gas generated by the combustion in the combustion chamber 11 is fed into the reboiler one 12 for heating the reboiler one 12.

[0076] The dehydrogenation reaction and product separation are carried out in the reaction distillation column 2, after the gas taken from the reaction distillation column 2 overhead is separated into gas and liquid by the condenser 3, the gas phase hydrogen can be temporarily stored in the hydrogen-rich storage tank 1 as the fuel cell system raw material, and the liquid phase is returned to the reaction distillation column 2 as the condensate. The heavy component kettle liquid composed of H0-BT and a small amount of H6-BT obtained from the reaction distillation column 2 kettle is sent to the hydrogen-poor storage tank 14 as the hydrogen-poor product for subsequent hydrogenation.

[0077] In the fuel cell system of this embodiment, hydrogen from the reactive rectification tower 2 is preheated to the inlet temperature by the hydrogen preheater 5 and then introduced into the anode of the SOFC stack 7, while air is preheated to the inlet temperature by the air preheater 8 and then introduced into the cathode of the SOFC stack 7. Electrochemical reactions occur in the cell to generate electricity. In the process of electricity generation, the unspent hydrogen is discharged from the SOFC anode as anode exhaust gas, and the unspent air is discharged from the SOFC cathode as cathode exhaust gas.

[0078] The anode exhaust gas discharged from the SOFC stack 7 anode exhaust gas outlet is used to provide the heating source for the hydrogen preheater 5 to heat the hydrogen, and the cathode exhaust gas discharged from the SOFC stack cathode is used to provide the heating source for the air preheater 8 to heat the air. Then, the two are directly mixed and sent to the combustion chamber 11 to undergo combustion reaction. The exhaust gas generated by the combustion is used to heat the reboiler 12 of the reactive rectification tower 2.

[0079] 26.12 kg / h of pure H12-BT raw material is introduced into the pressurized reactive rectification dehydrogenation tower from the top. The tower operates at a pressure of 1.8 bar, with a theoretical number of 5 in the reaction section, a total theoretical plate number of 8 in the reactive rectification tower 2, a reboiler ratio of 11.6 for the tower kettle reboiler, a reboiler temperature of 309.46°C, a tower top condenser 3 temperature of 40°C, a tower kettle take-off flow rate of 24.36 kg / h of H0-BT with a purity of 98.32%, which is sent to the hydrogen-lean storage tank 14 for subsequent hydrogenation; a tower top take-off flow rate of 1.59 kg / h of hydrogen with a purity of 99.99%, which is sent to the SOFC stack 7 as fuel.

[0080] In the atmospheric plate SOFC power generation system, the SOFC structure is composed of plate cells, which operate at atmospheric pressure. The SOFC cell operating temperature is 831.85°C, the gas inlet temperature is 831.85°C, the air excess coefficient is 2.6, the fuel utilization rate is 0.83, and the number of plate cells in the SOFC stack 7 is 1350.

[0081] The coupling system performance: the anode exhaust flow rate from SOFC stack 7 is 12.54 kg / h, the temperature is 831.85℃, the cathode exhaust flow rate is 42.77 kg / h, the temperature is 831.85℃, the anode and cathode exhausts are used to heat hydrogen and air respectively, the temperature of the anode exhaust is reduced to 205℃, the temperature of the cathode exhaust is reduced to 27℃, they are mixed and sent to the combustion chamber 11 for combustion reaction to produce a combustion exhaust with a flow rate of 55.31 kg / h and a temperature of 496℃, and finally the exhaust is sent to the reboiler of the reaction rectification column 2, thereby realizing the integration of the reaction rectification column 2 and the SOFC system. In the integration process, the hydrogen is heated to 830℃, the air is heated to 830℃, the kettle liquid in the reboiler is heated to form a reboiling vapor at 308.75℃, and at the same time, in order to ensure the stable operation of the SOFC system, an additional column kettle reboiler, an air preheater and a hydrogen preheater are provided to meet the process requirements. Finally, the entire system can generate 29.18 kW of electricity, achieve a power generation efficiency of 56.13%, the system energy consumption is 25.48 kW, the carbon emission is 0.274 kgCO2 / kWh, and the average electricity cost is 0.135 $ / kWh.

[0082] Example 2

[0083] As shown in Figure 2 , different from example 1, the reaction rectification column 2 in the coupling system of the rectification dehydrogenation and fuel cell in this embodiment is a normal pressure reaction rectification dehydrogenation column, and the fuel cell system is a normal pressure plate type SOFC. The hydrogen preheater 5 in this embodiment is connected between the combustion chamber 11 and the reboiler 12 and located before the anode gas inlet of the SOFC stack 7 for preheating the hydrogen entering the anode. The air preheater 8 is connected between the reboiler 12 and the cathode gas inlet of the SOFC stack 7 and located before the cathode gas inlet of the SOFC stack 7 for preheating the air entering the cathode.

[0084] The operating pressure of the reaction rectification column 2 is 1 bar, the temperature of the condenser 3 at the top of the column is 25-60℃, the reboiling ratio of the kettle reboiler is 10-20, the temperature of the reboiler is 225-350℃, the number of reaction stages is 1-15, and the total number of theoretical plates is 2-25.

[0085] In this embodiment, the cathode exhaust and the anode exhaust from the SOFC stack 7 are directly sent to the mixer 10 and then to the combustion chamber 11 for combustion reaction. The exhaust produced by the combustion is first sent to the hydrogen preheater 5, then to the reboiler 12, and then to the air preheater 8, which are used to heat hydrogen, the reboiler 12 and air in sequence.

[0086] In use, 23.32 kg / h of pure H12-BT raw material is fed into the reaction rectification column 2 from the top, the theoretical plate number of the reaction section in the column is 5, the theoretical plate number of the stripping section is 8, the reboiling ratio of the reboiler at the bottom of the column is 11.6, the temperature of the condenser 3 at the top of the column is 40°C, and the temperature of the reboiler is 281.53°C. The flow rate of H0-BT with a purity of 85.79% obtained from the bottom of the column is 21.75 kg / h, which is sent to the hydrogen storage tank 14 for subsequent hydrogenation; the flow rate of hydrogen with a purity of 99.98% obtained from the top of the column is 1.32 kg / h, which is sent to the SOFC stack 7 as fuel.

[0087] In the fuel cell system, the SOFC structure is composed of plate cells, which operates at normal pressure, the working temperature of the SOFC cell is 826.85°C, the gas inlet temperature is 826.85°C, the air excess coefficient is 2.5, the fuel utilization rate is 0.85, and the number of plate cells in the SOFC stack 7 is 1250.

[0088] The anode exhaust with a flow rate of 10.12 kg / h and a temperature of 826.85°C is discharged from the anode of the SOFC stack 7, and the cathode exhaust with a flow rate of 37.92 kg / h and a temperature of 826.85°C is discharged from the cathode. After mixing in the mixer 10, they are fed into the combustion chamber 11 for combustion reaction to produce combustion exhaust with a flow rate of 48.04 kg / h and a temperature of 1172°C. The exhaust is sequentially fed into the hydrogen preheater 1 5, the reboiler 1 2, and the air preheater 1 8 to heat hydrogen, the reboiler 1 2, and air, respectively, thereby realizing the integration of the reaction rectification column 2 and the SOFC system. By using the combustion exhaust, the hydrogen obtained from the top of the reaction rectification column 2 is heated to 826.85°C, the liquid in the reboiler is heated to form reboiling steam with a temperature of 281.23°C, and fresh air is heated to 281°C. At the same time, in order to ensure the stable operation of the SOFC system, an additional reboiler 1 3 and air preheater 9 are provided to meet the process requirements. Finally, the entire system can generate electricity of 25.05 kW, the power generation efficiency can reach 57.6%, the system energy consumption is 18.41 kW, the carbon emission is about 0.196 kg CO2 / kWh, and the average electricity cost is 0.106 $ / kWh.

[0089] Example 3

[0090] As shown in Figure 3 different from example 1, in the coupling system of the rectification dehydrogenation and fuel cell of the present example, the air preheater 1 8 is connected between the anode exhaust outlet of the SOFC stack 7 and the mixer 1 0 and located before the cathode gas inlet of the SOFC stack 7 for preheating the air fed into the cathode; the hydrogen preheater 1 5 is connected between the reboiler 1 2 and the anode gas inlet of the SOFC stack 7 for preheating the hydrogen fed into the anode. The reaction rectification column 2 of the present example adopts a back-pack type reaction rectification column.

[0091] The raw material inlet of the reactive distillation column 2 of the embodiment is provided with a pre-reactor 15, and the liquid phase side of the reactive distillation column 2 is provided with a back-pack reactor 16.

[0092] In the embodiment, 1-2 back-pack reactors are arranged between the column sections of the reactive distillation column 2, the inner diameter of the reactor is 0.3-2 meters, and the height is 0.5-2.5 meters.

[0093] In the embodiment, the reaction temperature of the pre-reactor 15 and the back-pack reactor 16 is 200-300℃. The reaction pressure of the pre-reactor 15 and the back-pack reactor 16 is 0.5-2.5 bar. The purity of the hydrogen gas taken out from the top of the reactive distillation column 2 is not less than 99%, the purity of H0-BT in the product taken out from the bottom of the reactive distillation column 2 is not less than 85%, and the dehydrogenation degree is not less than 30%.

[0094] In application, 24.46 kg / h of pure H12-BT raw material is introduced into the pre-reactor 15 for reaction, the reaction residence time is 0.5 h, the reaction temperature is 295℃, and the pressure is 1.6 bar. The material after reaction is introduced into the reactive distillation column 2 from the top, the operation pressure of the column is about 1.8 bar, the theoretical plate number of the reaction section is 5, the theoretical plate number of the stripping section is 8, the reboiling ratio of the column bottom reboiler is 11.6, the reboiler temperature is 309.58℃, and the temperature of the top condenser 3 is 40℃. The H0-BT with a purity of 99.25% taken out from the bottom of the reactive distillation column 2 at a flow rate of 22.81 kg / h is sent to the hydrogen storage tank 14 for subsequent hydrogenation; the hydrogen gas with a purity of 99.99% taken out from the top at a flow rate of 2.16 kg / h is sent to the SOFC stack 7 as fuel.

[0095] In the fuel cell system, the SOFC structure is composed of plate cells, the working temperature of the SOFC cell is 821.85℃, the gas inlet temperature is 821.85℃, the air excess coefficient is 2.3, the fuel utilization rate is 0.84, and the number of plate cells in the SOFC stack 7 is 1100.

[0096] The anode exhaust from SOFC stack 7 has a flow rate of 11.56 kg / h and a temperature of 821.85°C, and the cathode exhaust has a flow rate of 38.65 kg / h and a temperature of 821.85°C. The anode exhaust is first heated by air preheater 8 to heat the air to 447°C, and then the temperature of the anode exhaust is reduced to 95°C, and then the anode exhaust is mixed with the cathode exhaust and sent to combustion chamber 11 for combustion, and combustion exhaust having a flow rate of 50.21 kg / h and a temperature of 888°C is generated, and then the exhaust is sequentially used to heat reboiler 12 of reaction rectifying column 2 and hydrogen preheater 5 to heat the liquid in reboiler 12 to 308.81°C and hydrogen to 282°C, thereby achieving integration of reaction rectifying column 2 and the SOFC system. At the same time, in order to ensure stable operation of the SOFC system, additional reboiler 13, air preheater 9 and hydrogen preheater 6 are provided to meet the process requirements. Finally, the entire system can generate 28.67 kW of electricity, the power generation efficiency is 56.89%, the system energy consumption is 26.89 kW, the carbon emission is about 0.271 kg CO2 / kWh, and the average electricity cost is 0.121 $ / kWh.

[0097] Example 4

[0098] As shown in Figure 4 , unlike Example 2, in the distillation dehydrogenation and fuel cell coupled system of this example, hydrogen preheater 5 is connected between the anode exhaust outlet of SOFC stack 7 and mixer 10 and located before the anode gas inlet of SOFC stack 7 for preheating hydrogen entering the anode, and air preheater 8 is connected between combustion chamber 11 and reboiler 12 and located before the cathode gas inlet for preheating air entering the cathode.

[0099] SOFC stack 7 of this example is composed of tubular structure cells, and the stack is operated under pressure, and a GT turbine 19 is additionally provided in the SOFC power generation system. When the pressurized tubular SOFC system is used for power generation, the working temperature of SOFC stack 7 is 726.85-1126.85°C, the stack gas inlet temperature is 500-1000°C, the working pressure is 1-8 bar, the air excess coefficient is 2.5-5, the fuel utilization rate is 0.7-0.9, and the number of SOFC stack 7 cell sheets is 1000-6000.

[0100] The anode exhaust from SOFC stack 7 is first heated by hydrogen preheater 5 to heat hydrogen, and then directly mixed with the cathode exhaust, and then sent to combustion chamber 11 for combustion, and the combustion exhaust generated after combustion is sequentially used to heat air by air preheater 8, reboiler 12 of reaction rectifying column 2 and hydrogen by hydrogen preheater 5, thereby achieving integration of reaction rectifying column 2 and the SOFC system.

[0101] In application, 25.11 kg / h of pure H12-BT raw material is introduced into the single atmospheric pressure reaction rectification tower from the top, the theoretical plate number of the reaction section is 5, the theoretical plate number of the stripping section is 8, the reboiling ratio of the tower kettle reboiler is 11.6, the reboiler temperature is 281.53℃, the top condenser 3 temperature is 40℃, the reaction rectification tower 2 kettle adopts 23.42 kg / h of H0-BT with a purity of 85.79% to send to the hydrogen storage tank 14 for subsequent hydrogenation; the top adopts 1.44 kg / h of hydrogen with a purity of 99.98% to send to the SOFC stack 7 as fuel.

[0102] In the pressurized tubular SOFC power generation system, the SOFC structure is composed of tubular cells, which operates at a pressure of 5 bar, the gas compressor pressure ratio is 5, the SOFC cell operating temperature is 820.85℃, the gas inlet temperature is 820℃, the air excess coefficient is 2.4, the fuel utilization rate is 0.86, and the number of tubular cells in the SOFC stack 7 is 1150.

[0103] The anode exhaust flow from the SOFC stack 7 is 11.09 kg / h at a temperature of 820.85℃, and the cathode exhaust flow is 40.58 kg / h at a temperature of 820.85℃. The anode exhaust is heated to 370℃, and then the temperature drops to 542℃, and then mixed with the cathode exhaust to send to the combustion chamber 11 for combustion reaction, and generates a combustion exhaust flow of 51.67 kg / h at 906℃, and then the combustion exhaust is sequentially heated to the reboiler one 12 and the air preheater one 8, the kettle liquid in the reboiler one 12 is heated to 308.81℃, and the air in the air preheater one 8 is heated to 405℃, thereby realizing the integration of the reaction rectification tower 2 and the fuel cell system. At the same time, in order to ensure the stable operation of the fuel cell system, an additional kettle reboiler two 13 is additionally provided to meet the process requirements. Finally, the entire system can generate 30.26 kW of electricity, the power generation efficiency can reach 58.13%, the system energy consumption is 29.87 kW, the carbon emission is about 0.293 kgCO2 / kWh, and the average electricity cost is 0.128 $ / kWh.

[0104] It should be understood that the application of the present application is not limited to the above examples, and those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the present application.

Claims

1. A coupling system for distillation dehydrogenation and fuel cell, characterized in that, The system comprises a rectification dehydrogenation system, a fuel cell system, a mixer, a combustion chamber, The rectification dehydrogenation system comprises a reaction rectification tower, a reboiler one, the reboiler one is communicated with the bottom of the reaction rectification tower, The fuel cell system comprises a SOFC stack, the SOFC stack comprises an anode and a cathode, the anode exhaust outlet of the SOFC stack is communicated with the mixer, the cathode exhaust outlet of the SOFC stack is communicated with the mixer, the mixer is communicated with the combustion chamber, The combustion tail gas of the combustion chamber is communicated with the reboiler one, which is used for providing the heating source of the reboiler one.

2. The system according to claim 1, wherein the system further comprises a fuel cell. The fuel cell system further comprises a hydrogen preheater one, which is connected between the anode exhaust outlet of the SOFC stack and the mixer and before the anode gas inlet of the SOFC stack for preheating the hydrogen entering the anode; Or the hydrogen preheater one is connected between the combustion chamber and the reboiler one and before the anode gas inlet of the SOFC stack for preheating the hydrogen entering the anode; Or the hydrogen preheater one is connected between the reboiler one and the anode gas inlet of the SOFC stack for preheating the hydrogen entering the anode.

3. The system according to claim 1, wherein the system further comprises a fuel cell. The fuel cell system further comprises an air preheater one, which is connected between the cathode exhaust outlet of the SOFC stack and the mixer and before the cathode gas inlet of the SOFC stack for preheating the air entering the cathode; Or the air preheater one is connected between the reboiler one and the cathode gas inlet of the SOFC stack for preheating the air entering the cathode; Or the air preheater one is connected between the anode exhaust outlet of the SOFC stack and the mixer and before the cathode gas inlet of the SOFC stack for preheating the air entering the cathode; Or the air preheater one is connected between the combustion chamber and the reboiler one and before the cathode gas inlet for preheating the air entering the cathode.

4. The system according to claim 2 or 3, wherein the system further comprises a fuel cell. The fuel cell system further comprises a hydrogen preheater two arranged between the hydrogen preheater one and the anode, and an air preheater two arranged between the air preheater one and the cathode.

5. The system of claim 1, wherein the system further comprises a fuel cell. The top hydrogen stream outlet of the reaction rectification tower is communicated with the anode of the SOFC stack, and a condenser and a pressure relief valve are arranged between the top hydrogen stream outlet of the reaction rectification tower and the anode of the SOFC stack.

6. The system of claim 1, wherein the system further comprises a fuel cell. The reboiler two is further arranged between the reboiler one and the bottom of the reaction rectification tower.

7. The system of claim 1, wherein the system further comprises a fuel cell. The fuel cell system further comprises a GT turbine and a generator, and the combustion tail gas of the combustion chamber is communicated with the GT turbine for providing power for the power generation of the GT turbine.

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