Scheduling hydrogen production system coupling solar energy storage and adsorption-enhanced methane steam reforming

Abstract

The invention belongs to the field of energy and chemical industry, and particularly relates to a scheduling hydrogen production system for coupling solar energy storage and adsorption-enhanced methane steam reforming. The system comprises a reaction module, a heat exchange module and a storage module, the operation mode is divided into a daytime mode and a night mode; the reaction module comprises a calcination reactor, a first gas-solid separator, a first adsorption-enhanced methane reforming reactor, a second gas-solid separator, a carbonation reactor, a third gas-solid separator, a second adsorption-enhanced methane reforming reactor and a fourth gas-solid separator; the heat exchange module comprises twelve heat exchangers and two turbines. According to the system, renewable energy solar energy is used as a system energy source, a calcium-based material is used as an energy storage medium and an adsorption-enhanced methane steam reforming medium, continuous utilization of solar energy and scheduling preparation of high-purity hydrogen can be achieved, and the system has a good application prospect in promotion of renewable energy utilization and clean energy preparation. And the construction of a clean and low-carbon energy system is of great significance.

Description

Technical Field

[0001] The present invention belongs to the field of energy and chemical industry, and in particular relates to a scheduling hydrogen production system for coupling solar energy storage and adsorption-enhanced methane steam reforming. Background Art

[0002] Hydrogen energy is a clean and efficient secondary energy source. Due to its abundant reserves and zero-carbon emission potential, it has become an important research direction in the energy field in recent years. At present, industrial hydrogen production mainly relies on technologies such as coal gasification, methane steam reforming and water electrolysis. Among them, methane steam reforming is widely used because of its high conversion efficiency and low hydrogen production cost. However, this traditional process consumes a large amount of fossil fuels and is accompanied by a large amount of carbon dioxide emissions, which puts great pressure on the environment. With the increasing global demand for clean energy and the proposal of carbon neutrality goals, it is particularly important to develop efficient hydrogen production technologies that can reduce carbon emissions and combine renewable energy.

[0003] Adsorption-enhanced steam methane reforming (SE-SMR) is an advanced hydrogen production technology that has received widespread attention in recent years. This technology breaks the limitation of reaction equilibrium by dynamically removing the carbon dioxide generated in the reaction through adsorbents, thereby significantly improving the hydrogen yield and reaction efficiency. In existing research, calcium-based materials (such as CaO) are widely used to adsorb carbon dioxide, which undergoes a carbonation reaction (CaO+CO2→CaCO3) under high temperature conditions to achieve efficient capture of carbon dioxide.

[0004] As a clean and renewable energy source, solar energy has gradually become an important energy source in the industrial field due to its wide availability and low-carbon characteristics. However, due to its intermittent and volatile nature, solar energy has poor energy supply stability and is difficult to meet the demand for stable energy supply in industry. In existing research, solar energy storage technology can solve this problem, including latent heat storage, sensible heat storage and thermochemical energy storage. Among them, thermochemical energy storage using calcium-based materials as the medium is widely used in the field of concentrated solar power generation due to its low price and high heat storage density. It is used to achieve stable storage and supply of solar energy.

[0005] In summary, existing technologies have been extensively studied in the fields of adsorption enhanced methane steam reforming hydrogen production and solar energy storage power generation. However, there is insufficient research on how to promote the combination of renewable energy and adsorption enhanced methane steam reforming hydrogen production technology. Therefore, exploring the efficient application of renewable energy in the hydrogen production process is an effective direction to promote further development in this field. Summary of the invention

[0006] In view of the problems and shortcomings in the prior art, the object of the present invention is to provide a scheduling hydrogen production system that couples solar energy storage and adsorption-enhanced methane steam reforming.

[0007] Based on the above purpose, the present invention adopts the following technical solution:

[0008] The present invention provides a scheduling hydrogen production system that couples solar energy storage and adsorption-enhanced methane steam reforming, including a reaction module, a heat exchange module and a storage module; the operation mode is divided into a day mode and a night mode;

[0009] The reaction module includes a calcination reactor, a first gas-solid separator, a first adsorption enhanced methane reforming reactor, a second gas-solid separator, a carbonation reactor, a third gas-solid separator, a second adsorption enhanced methane reforming reactor, and a fourth gas-solid separator. The inlets of the gas-solid separators are all connected to the reactor outlets, and the two outlets of the third gas-solid separator and the fourth gas-solid separator are both connected to the heat exchanger; the heat exchange module includes 12 heat exchangers and 2 turbines, and the inlet and outlet of the heat exchanger are directly or indirectly connected to the gas-solid separator outlet and the reactor inlet respectively, the inlet of the first turbine is connected to the hot outlet of the seventh heat exchanger, the outlet of the first turbine is connected to the inlet of the CO2 high-pressure gas cylinder, the inlet of the second turbine is connected to the cold outlet of the eleventh heat exchanger, and the outlet of the second turbine is connected to the cold inlet of the twelfth heat exchanger;

[0010] In the daytime mode, CaCO3 solid absorbs the heat generated by the concentrated solar receiver in the calcination reactor to calcine to generate CaO solid and CO2 gas, wherein a portion of the CaO solid enters the first adsorption enhanced methane reforming reactor to generate CaCO3 solid, and then re-enters the calcination reactor to be calcined, and the remaining CaO solid directly enters the CaO storage tank for storage, at the same time, the first adsorption enhanced methane reforming reactor absorbs solar heat, and CH4 and H2O in the reactor react to obtain H2 gas; the waste heat carried by the products in the calcination reactor and the first adsorption enhanced methane reforming reactor is recycled through the first heat exchanger, the second heat exchanger, the third heat exchanger and the fourth heat exchanger;

[0011] In night mode, the high-pressure CO2 gas in the CO2 high-pressure cylinder enters the second turbine to release energy and generate electricity, and then enters the carbonation reactor to undergo a carbonation reaction with a portion of the CaO solid transported from the CaO storage tank to release heat, and the reaction products provide heat for the methane steam reforming reaction; at the same time, the remaining CaO solid transported from the CaO storage tank directly enters the second adsorption enhanced methane reforming reactor to participate in the reaction; in addition, the electric energy generated by the first turbine and the second turbine is used to supplement the heat source of the second adsorption enhanced methane reforming reactor through electric heating to enable the reaction to proceed completely.

[0012] Furthermore, the calcination reactor is used to receive tower concentrated solar radiation to decompose the reactant CaCO3 particles into CaO and CO2 by endothermic absorption, and store solar energy in the form of chemical energy and sensible heat. The carbonation reactor is indirectly connected to the CaO storage tank and the CO2 high-pressure gas cylinder, and is used to cause the carbonation reaction of CaO to release the energy stored in the form of chemical energy as an energy source for the adsorption enhanced methane reforming reaction. The first adsorption enhanced methane reforming reactor and the second adsorption enhanced methane reforming reactor are used for methane steam reforming hydrogen production reaction, and are connected to the outlet of each reactor by a gas-solid separator to separate the gas phase and solid phase of the reaction product for easy storage and transportation.

[0013] Furthermore, in the daytime mode, the CO2 gas produced by the calcination reactor enters the first heat exchanger to exchange heat with the room temperature liquid water of the input system, so that it forms water vapor and enters the first adsorption enhanced methane reforming reactor, and then the CO2 gas continues to enter the fourth heat exchanger to exchange heat with the CH4 gas of the input system.

[0014] Furthermore, in the night mode, CaO and CO2 gases in the carbonation reactor react to release heat, which is carried out of the carbonation reactor in the form of sensible heat by the product CaCO3 solid and the remaining CO2 gas of the reaction. After separation by the third gas-solid separator, the heat released by the carbonation reaction is transferred to the H2O input into the system through the seventh heat exchanger and the eighth heat exchanger respectively, providing heat for the methane steam reforming reaction, and then stored in the CaCO3 storage tank and the CO2 high-pressure gas cylinder respectively.

[0015] Furthermore, the CaO solid generated by calcination in the calcination reactor is stored in a CaO storage tank and used for the first adsorption enhanced methane reforming reaction in a ratio of 7:2; the CaO solid in the CaO storage tank is used for carbonation reaction and for the second adsorption enhanced methane reforming reaction in a ratio of 3:2.

[0016] Furthermore, the calcination reactor and the carbonation reactor are both fluidized bed reactors, the calcination reactor is connected to a concentrating solar receiver, the first adsorption enhanced methane reforming reactor and the second adsorption enhanced methane reforming reactor are both fixed bed reactors; and the heat exchangers are both countercurrent shell and tube heat exchangers.

[0017] Furthermore, the storage module includes a CaCO3 storage tank, a CaO storage tank, a CO2 high-pressure gas cylinder, a cooler and a compressor; one inlet of the CaCO3 storage tank is indirectly connected to the outlet of the carbonation reactor via the third gas-solid separator and the eighth heat exchanger in sequence, and the other inlet of the CaCO3 storage tank is indirectly connected to the outlet of the second adsorption enhanced methane reforming reactor via the fourth gas-solid separator, the ninth heat exchanger, the fifth heat exchanger and the sixth heat exchanger in sequence, and the CaCO3 storage tank outlet is connected to the top inlet of the calcination reactor through the second heat exchanger; the CaO storage tank inlet is indirectly connected to the outlet of the carbonation reactor via the first gas-solid separator and the first diverter in sequence, and the CaO storage tank outlet is respectively connected to the lower inlet of the carbonation reactor and the upper inlet of the second adsorption enhanced methane reforming reactor through the second diverter; the cooler outlet is connected to the compressor inlet, the compressor outlet is connected to one of the inlets of the CO2 high-pressure gas cylinder, and the CO2 high-pressure gas cylinder outlet is connected to the second turbine via the sixth heat exchanger and the eleventh heat exchanger in sequence.

[0018] Furthermore, the CaCO3 storage tank is a normal temperature and pressure storage tank, the CaO storage tank is a high temperature and normal pressure storage tank, and an insulated storage tank is adopted with a storage temperature of 700°C. The CO2 high-pressure gas cylinder is a normal temperature and high-pressure gas cylinder with a storage pressure of 75 bar.

[0019] Furthermore, the reaction medium in the calcination reactor is a solid calcium carbonate-based material; the reaction medium in the carbonation reactor is a solid calcium oxide-based material and carbon dioxide gas; the reaction medium in the first adsorption enhanced methane reforming reactor and the second adsorption enhanced methane reforming reactor is methane gas, liquid water and solid calcium oxide particles, and the catalyst loaded in the reactor is a Ni-based catalyst.

[0020] Furthermore, the solid calcium carbonate-based material is solid calcium carbonate particles; the solid calcium oxide-based material is solid calcium oxide particles.

[0021] Furthermore, when there is sufficient solar energy during the day, the first adsorption enhanced methane steam reforming reactor uses solar energy as a heat source, and when there is no solar energy at night, the second adsorption enhanced methane steam reforming reactor uses the heat released by the carbonation reactor as a heat source.

[0022] Furthermore, the sum of the solar input powers of the calcination reactor and the first adsorption enhanced methane reforming reactor is 100 MW; the temperature of the calcination reactor is 900°C and the pressure is 1 bar; the ratio of CH4:H2O in the first adsorption enhanced methane reforming reactor and the second adsorption enhanced methane reforming reactor is 1:2 by volume, the reaction temperature is 650°C, and the reaction pressure is 1 bar.

[0023] Furthermore, the storage temperature in the CaO storage tank is 700°C; the storage pressure in the CO2 high-pressure cylinder is 75 bar.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The system's two operating modes, daytime and nighttime, are conducive to storing a portion of solar energy in the form of chemical energy through the CaCO3 calcination reaction when there is sufficient sunlight, and using it as a reserve heat source for the methane reforming hydrogen production reaction when there is insufficient sunlight or at night. This overcomes the intermittent problem of solar energy, realizes the dispatchability of solar energy utilization, and completes the continuous preparation of high-purity hydrogen.

[0026] (2) The system uses solid CaO particles to absorb and enhance the CO2 gas produced by the methane steam reforming reaction, promoting hydrogen generation and obtaining high-purity hydrogen.

[0027] (3) The system utilizes a heat exchange module, especially a heat exchange module including 12 heat exchangers and 2 turbines. The inlet and outlet of the heat exchanger are directly or indirectly connected to the outlet of the gas-solid separator and the inlet of the reactor respectively. The inlet of the first turbine is connected to the hot outlet of the seventh heat exchanger, the outlet of the first turbine is connected to the inlet of the CO2 high-pressure gas cylinder, the inlet of the second turbine is connected to the cold outlet of the eleventh heat exchanger, and the outlet of the second turbine is connected to the cold inlet of the twelfth heat exchanger, forming a heat exchange network to recycle and utilize waste heat of materials, thereby greatly improving the energy utilization rate of the system and achieving system energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the structure of the scheduling hydrogen production system of the present invention coupling solar energy storage and adsorption enhanced methane steam reforming;

[0029] Figure 2 The figure is a calculation process model diagram of the system of the present invention in the daytime mode;

[0030] Figure 3 This is a model diagram of the calculation process of the system of the present invention in night mode.

[0031] In the figure: calcination reactor 1; first adsorption enhanced methane reforming reactor 2; CaCO3 storage tank 3; CaO storage tank 4; CO2 high-pressure gas cylinder 5; carbonation reactor 6; second adsorption enhanced methane reforming reactor 7; first gas-solid separator S1; second gas-solid separator S2; third gas-solid separator S3; fourth gas-solid separator S4; first heat exchanger HX1; second heat exchanger HX2; third heat exchanger HX3; fourth heat exchanger HX4; fifth heat exchanger HX5; sixth heat exchanger HX6; seventh heat exchanger HX7; eighth heat exchanger HX8; ninth heat exchanger HX9; tenth heat exchanger HX10; eleventh heat exchanger HX11; twelfth heat exchanger HX12; cooler CL1; compressor COMP; first turbine T1; second turbine T2; first splitter SEU1; second splitter SEU2. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through embodiments in combination with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] Example 1

[0034] This embodiment provides a scheduling hydrogen production system that couples solar energy storage and adsorption-enhanced methane steam reforming, as shown in the schematic diagram. Figure 1 As shown, it includes a reaction module, a heat exchange module and a storage module; the operation mode is divided into a day mode and a night mode;

[0035] The reaction module includes a calcination reactor 1, a first gas-solid separator S1, a first adsorption-enhanced methane reforming reactor 2, a second gas-solid separator S2, a carbonation reactor 6, a third gas-solid separator S3, a second adsorption-enhanced methane reforming reactor 7, and a fourth gas-solid separator S4. The inlets of the gas-solid separators are all connected to the reactor outlets, and the two outlets of the third gas-solid separator and the fourth gas-solid separator are both connected to the heat exchanger; the calcination reactor 1 and the carbonation reactor 6 are both fluidized bed reactors, the calcination reactor 1 is connected to a concentrating solar receiver, the first adsorption-enhanced methane reforming reactor 7 is connected to the concentrating solar receiver, and the second adsorption-enhanced methane reforming reactor 7 is connected to the concentrating solar receiver. The reforming reactor 2 and the second adsorption enhanced methane reforming reactor 7 are both fixed bed reactors; the reaction medium in the calcination reactor 1 is a solid calcium carbonate-based material; the reaction medium in the carbonation reactor 6 is a solid calcium oxide-based material and carbon dioxide gas; the reaction medium in the first adsorption enhanced methane reforming reactor 2 and the second adsorption enhanced methane reforming reactor 7 is methane gas, liquid water and solid calcium oxide particles, and the catalyst loaded in the reactor is a Ni-based catalyst; the solid calcium carbonate-based material is solid calcium carbonate particles; the solid calcium oxide-based material is solid calcium oxide particles.

[0036] The heat exchange module includes 12 heat exchangers and 2 turbines. The inlet and outlet of the heat exchanger are directly or indirectly connected to the outlet of the gas-solid separator and the inlet of the reactor respectively. The inlet of the first turbine T1 is connected to the hot outlet of the seventh heat exchanger HX7, the outlet of the first turbine T1 is connected to the inlet of the CO2 high-pressure gas cylinder 5, the inlet of the second turbine T2 is connected to the cold outlet of the eleventh heat exchanger HX11, and the outlet of the second turbine T2 is connected to the cold inlet of the twelfth heat exchanger HX12; the heat exchangers are all countercurrent shell and tube heat exchangers.

[0037] The storage module includes a CaCO3 storage tank 3, a CaO storage tank 4, a CO2 high-pressure gas cylinder 5, a cooler CL1 and a compressor COMP; the storage temperature in the CaO storage tank 4 is 700°C, and the storage pressure in the CO2 high-pressure gas cylinder 5 is 75 bar; one inlet of the CaCO3 storage tank 3 is indirectly connected to the outlet of the carbonation reactor 6 through the third gas-solid separator S3 and the eighth heat exchanger HX8 in sequence, and the other inlet of the CaCO3 storage tank 3 is indirectly connected to the outlet of the second adsorption enhanced methane reforming reactor 7 through the fourth gas-solid separator S4, the ninth heat exchanger HX9, the fifth heat exchanger HX5 and the sixth heat exchanger HX6 in sequence. The outlet of tank 3 is connected to the top inlet of calcination reactor 1 through the second heat exchanger HX2; the inlet of CaO storage tank 4 is indirectly connected to the outlet of carbonation reactor 6 through the first gas-solid separator S1 and the first splitter SEU1 in sequence, and the outlet of CaO storage tank 4 is respectively connected to the lower inlet of carbonation reactor 6 and the upper inlet of second adsorption enhanced methane reforming reactor 7 through the second splitter SEU2; the outlet of cooler CL1 is connected to the inlet of compressor COMP, the outlet of compressor COMP is connected to one of the inlets of CO2 high-pressure gas cylinder 5, and the outlet of CO2 high-pressure gas cylinder 5 is connected to the second turbine T2 through the sixth heat exchanger HX6 and the eleventh heat exchanger HX11 in sequence.

[0038] In the daytime mode, the CaCO3 solid absorbs the heat generated by the concentrated solar receiver in the calcination reactor 1 and is calcined at 900°C and 1 bar to generate CaO solid and CO2 gas. The CaO solid calcined in the calcination reactor 1 enters the CaO storage tank 4 for storage and is used for the first adsorption enhanced methane reforming reaction in a ratio of 7:2, wherein the CaO solid enters the first adsorption enhanced methane reforming reactor 2 to generate CaCO3 solid, and then re-enters the calcination reactor 1 to be calcined, and the remaining CaO solid directly enters the CaO storage tank 4 for storage; the CO2 gas generated by the calcination reactor 1 enters the first heat exchanger HX1 The CO2 gas exchanges heat with the room-temperature liquid water of the input system to form water vapor and enter the first adsorption enhanced methane reforming reactor 2, and then the CO2 gas continues to enter the fourth heat exchanger HX4 to exchange heat with the CH4 gas of the input system; at the same time, the first adsorption enhanced methane reforming reactor 2 absorbs solar heat, and the volume ratio of CH4 and H2O in the reactor is 1:2, and H2 gas is obtained by reverse reaction at 650°C and 1 bar; the waste heat carried by the products in the calcination reactor 1 and the first adsorption enhanced methane reforming reactor 2 is recycled through the first heat exchanger HX1, the second heat exchanger HX2, the third heat exchanger HX3 and the fourth heat exchanger HX4.

[0039] In night mode, the high-pressure CO2 gas in the CO2 high-pressure gas cylinder 5 enters the second turbine T2 to release energy and generate electricity, and then enters the carbonation reactor 6. The CaO solid in the CaO storage tank 4 is used for the carbonation reaction and for the second adsorption enhanced methane reforming reaction in a ratio of 3:2, wherein the CaO solid transported from the CaO storage tank 4 enters the carbonation reactor 6 to react with the CO2 gas for carbonation to release heat, and the reaction products provide heat for the methane steam reforming reaction. The CaO and CO2 gas in the carbonation reactor 6 react to release heat, which is carried out of the carbonation reactor 6 in the form of sensible heat by the product CaCO3 solid and the remaining CO2 gas of the reaction, and is separated by the third gas-solid separator S3. After separation, the heat released by the carbonation reaction is transferred to the H2O input into the system through the seventh heat exchanger HX7 and the eighth heat exchanger HX8 respectively, providing heat for the methane steam reforming reaction, and then stored in the CaCO3 storage tank and the CO2 high-pressure gas cylinder respectively; at the same time, the CaO solid transported from the CaO storage tank 4 directly enters the second adsorption enhanced methane reforming reactor 7 for adsorption enhanced methane reforming reaction, and the volume ratio of CH4 and H2O in the reactor is 1:2, and the reverse reaction is carried out at 650°C and 1 bar to obtain H2 gas; in addition, the electric energy generated by the first turbine T1 and the second turbine T2 is used to supplement the heat source for the second adsorption enhanced methane reforming reactor 7 by electric heating to make the reaction complete.

[0040] When there is sufficient solar energy during the day, the first adsorption enhanced methane steam reforming reactor 2 uses solar energy as a heat source. When there is no solar energy at night, the second adsorption enhanced methane steam reforming reactor 7 uses the heat released by the carbonation reactor as a heat source.

[0041] During production, in the daytime mode, the CaCO3 solid in the CaCO3 storage tank 3 is preheated by the second heat exchanger HX2 and then enters the calcination reactor 1. The calcination reactor 1 absorbs the heat generated by the concentrated solar receiver to calcine CaCO3 to generate CaO solid and CO2 gas. The CaO solid calcined in the calcination reactor 1 enters the CaO storage tank 4 for storage and is used for the first adsorption enhanced methane reforming reaction in a ratio of 7:2, wherein the CaO solid is separated by the first gas-solid separator S1 and then passes through the first diverter SEU1. A part of the CaO solid enters the first adsorption enhanced methane reforming reactor 2, where the CO2 gas generated by the adsorption reaction is generated to generate CaCO3 solid, which is then separated by the second gas-solid separator S2 and then re-enters the calcination reactor 1 to be calcined, forming a cycle of calcium-based materials, and the remaining CaO solid directly enters the CaO storage tank 4 for storage; The CO2 gas produced in the calcination reactor 1 is separated by the first gas-solid separator S1 and then enters the first heat exchanger HX1 to exchange heat with the room temperature liquid water of the input system, so that it forms water vapor and enters the first adsorption enhanced methane reforming reactor 2. Then the CO2 gas continues to enter the fourth heat exchanger HX4 to exchange heat with the CH4 gas of the input system, and then enters the cooler CL1 to be cooled and compressed to 75 bar by the compressor COMP and then stored in the CO2 high-pressure gas cylinder 5; at the same time, the first adsorption enhanced methane reforming reactor 2 also absorbs solar heat to produce methane water vapor reforming reaction, and the CaCO3 solid and H2 gas produced by the reaction are separated by the second gas-solid separator S2, and the CaCO3 solid directly enters the calcination reactor 1 to be calcined, while the H2 gas is cooled by the third heat exchanger HX3 and the second heat exchanger HX2 to obtain high-purity H2 gas.

[0042] In the night mode, the high-pressure CO2 gas in the CO2 high-pressure gas cylinder 5 passes through the sixth heat exchanger HX6 and the eleventh heat exchanger HX11 successively, enters the turbine T2 to release energy and generate electricity, and then enters the twelfth heat exchanger HX12 for preheating before entering the carbonation reactor 6. The CaO solid in the CaO storage tank 4 is used for the carbonation reaction and for the second adsorption enhanced methane reforming reaction in a ratio of 3:2, wherein a portion of the high-temperature CaO solid transported from the CaO storage tank 4 through the second diverter SEU2 enters the carbonation reactor 6 to react with the CO2 gas to generate CaCO3 solid, releasing a large amount of heat, which is carried out of the carbonation reactor 6 in the form of sensible heat by the product CaCO3 solid and the remaining CO2 gas of the reaction, and after separation by the gas-solid separator S3, the heat released by the carbonation reaction is transferred to the H2O input into the system through the seventh heat exchanger HX7 and the eighth heat exchanger HX8, respectively, The methane steam reforming reaction provides heat, which is then stored in the CaCO3 storage tank 4 and the CO2 high-pressure gas cylinder 5 respectively; at the same time, the remaining high-temperature CaO solid transported from the CaO storage tank 4 directly enters the second adsorption enhanced methane reforming reactor 7, and the room-temperature liquid water input into the system absorbs the waste heat of the reforming product CaCO3 solid through the ninth heat exchanger HX9, and then passes through the eighth heat exchanger HX8 and the seventh heat exchanger HX7 in turn to absorb heat and then carry a large amount of heat into the second adsorption enhanced methane reforming reactor 7 for adsorption enhanced methane reforming reaction, while the CH4 gas input into the system is preheated through the fifth heat exchanger HX5 and the tenth heat exchanger HX10 in turn and then enters the second adsorption enhanced methane reforming reactor 7 to participate in the reaction, and the electric energy generated by the first turbine T1 and the second turbine T2 is used as a supplementary heat source for the second adsorption enhanced methane reforming reactor 7 through electric heating to ensure that the reforming reaction is complete.

[0043] Example 2

[0044] This embodiment provides Aspen simulation tests performed on the day mode and night mode of the system of the present invention.

[0045] Under the operating conditions shown in Table 1 below, the system was simulated using Aspen plus V11 software:

[0046] Table 1: System simulation operation parameter settings

[0047]

[0048] like Figure 2 The calculation process model of the system in the day mode is shown in Table 2. The values ​​of the main parameters such as the temperature, pressure, flow rate, molar enthalpy and molar entropy of each logistics are calculated and shown in Table 2 below:

[0049] Table 2: Main parameter values ​​of each logistics when the system is running in day mode

[0050]

[0051]

[0052] According to the above results, the energy analysis of the daytime mode of the system shows that when 100MW of solar energy is introduced into the system, 95.75MW of solar energy is directly applied to the calcination reactor, and 4.25MW of solar energy is directly applied to the first adsorption enhanced methane reforming hydrogen production reactor. In the calcination reactor, 52.93% of the solar energy is stored in the product CaO and CO2 in the form of chemical energy, 21.17% of the solar energy indirectly enters the adsorption enhanced reforming reactor through the calcined product CaO to provide energy for the reforming reaction, and the remaining 47.06% of the solar energy is carried by the reaction products CaO and CO2 in the form of sensible heat. In addition, 60.70% of the solar energy absorbed by the adsorption enhanced methane reforming reactor is also carried by the reaction products in the form of sensible heat. These sensible heats can be recovered through the heat exchange network and used to preheat the reactants of the calcination reaction and the adsorption enhanced methane reforming reaction to achieve efficient energy utilization. The waste heat recovery efficiency of the heat exchange network in the daytime mode is 62.71%.

[0053] In daytime mode, 60.26% of the solar energy input to the system is stored through the reaction products CaO and CO2 as the energy source in nighttime mode; the system energy loss rate is 38.06%, which includes compression loss (accounting for 12.46%), cooling loss (accounting for 10.39%), and waste heat waste (15.19%); the molar flow rate of hydrogen that can be generated by the daytime mode system is 474.99 mol / s, and the system daytime hydrogen yield is 66.88%.

[0054] like Figure 3 The calculation process model of the system in night mode is shown below. The values ​​of the main parameters such as temperature, pressure, flow rate, molar enthalpy and molar entropy of each stream are calculated and shown in Table 3 below:

[0055] Table 3: Main parameter values ​​of each logistics when the system is running in night mode

[0056]

[0057]

[0058] According to the above results, the energy analysis of the night mode of the system shows that the system energy of the night mode comes from the solar energy stored in the day mode. In the night mode, the carbonation reaction releases 10.67MW of energy, of which 57.67% is used to heat the reactants to the reaction temperature, and the remaining 42.32% is taken out of the calcination reactor by the unreacted reactants and reaction products, and is used to evaporate and preheat the H2O entering the reforming reactor; the waste heat of the carbonation reactor and the reforming reactor products is recovered through the heat exchanger network, which is used to preheat the reactants of the carbonation reaction and the adsorption enhanced methane reforming reaction. The waste heat recovery efficiency of the heat exchanger network in the night mode is 84.85%. After preheating the reactants, the adsorption enhanced methane reforming reactor still requires a heat load of 1.77MW, which is provided by turbines T1 and T2. In night mode, the system's energy loss rate is 13.75%, which is due to CaO storage loss (4.47%) and waste heat waste (9.28%). The molar flow rate of hydrogen generated by the system in night mode is 474.99 mol / s, and the system's nighttime hydrogen yield is 50.38%.

[0059] Combining the results of the two operation modes, the system is calculated by the following formula under the conditions of 100MW solar power and 12h sunshine time:

[0060] System flow conservation conditions:

[0061] F CA，clc =F CA，SMR，day +F CA，SMR，night +F CA，carb ,

[0062] Among them, F CA,c1c : Ca flow rate of calcination reactor, F CA,SMR,day : Ca flow rate of the adsorption-enhanced reforming reactor in day mode, F CA,SMR,night : Ca flow rate of the adsorption-enhanced reforming reactor in day mode, F CA,carb : Ca flow rate of carbonation reactor;

[0063] System energy conditions:

[0064] Q clc +Q SMR，day =Q sun

[0065] Q carb -Q SMR，night >0,

[0066] Among them, Q c1c : Calcination reaction heat load, Q SMR,day : Daily adsorption enhanced reforming reaction heat load, Q sun : Solar input, Q SMR,night : Daily adsorption enhanced reforming reaction heat load, Qcarb : Carbonation reaction heat load;

[0067] System evaluation indicators:

[0068] Solar hydrogen production efficiency:

[0069]

[0070] Among them, n H2 : Molar amount of hydrogen produced by the system, HHV H2 : Hydrogen calorific value, n CH4 : molar amount of methane input to the system, HHV CH4 : Methane calorific value, q solar : System solar input load, q comp : System compressor input load, HHV H2 286 kJ / mol, HHV CH4 It is 888.3 kJ / mol, and the hydrogen production rate for the whole day is 57.47%.

[0071] In summary, the scheduling hydrogen production system coupled with solar energy storage and adsorption-enhanced methane steam reforming provided by the present invention is based on the concept of existing solar energy storage and power generation systems, uses calcium-based materials as energy storage and CO2 adsorption materials, and couples solar energy storage and adsorption-enhanced methane steam reforming hydrogen production systems. It overcomes the intermittent problem of solar energy and achieves the goal of using solar energy to prepare high-purity hydrogen in a schedulable manner throughout the day. It has broad promotion and application prospects in promoting the development and utilization of clean renewable energy and the field of methane hydrogen production technology.

[0072] The above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the protection scope of the present invention. Those skilled in the art can modify or replace the technical solution of the present invention according to the idea of ​​the present invention without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A scheduling hydrogen production system coupling solar energy storage and adsorption enhanced methane steam reforming, characterized in that: It includes reaction module, heat exchange module and storage module; the operation mode is divided into day mode and night mode; The reaction module includes a calcination reactor, a first gas-solid separator, a first adsorption enhanced methane reforming reactor, a second gas-solid separator, a carbonation reactor, a third gas-solid separator, a second adsorption enhanced methane reforming reactor, and a fourth gas-solid separator. The inlets of the gas-solid separators are all connected to the reactor outlets, and the two outlets of the third gas-solid separator and the fourth gas-solid separator are both connected to the heat exchanger; the heat exchange module includes 12 heat exchangers and 2 turbines, and the inlet and outlet of the heat exchanger are directly or indirectly connected to the gas-solid separator outlet and the reactor inlet respectively, the inlet of the first turbine is connected to the hot outlet of the seventh heat exchanger, the outlet of the first turbine is connected to the inlet of the CO2 high-pressure gas cylinder, the inlet of the second turbine is connected to the cold outlet of the eleventh heat exchanger, and the outlet of the second turbine is connected to the cold inlet of the twelfth heat exchanger; In the daytime mode, CaCO3 solid absorbs the heat generated by the concentrated solar receiver in the calcination reactor to calcine to generate CaO solid and CO2 gas, wherein a portion of the CaO solid enters the first adsorption enhanced methane reforming reactor to generate CaCO3 solid, and then re-enters the calcination reactor to be calcined, and the remaining CaO solid directly enters the CaO storage tank for storage, at the same time, the first adsorption enhanced methane reforming reactor absorbs solar heat, and CH4 and H2O in the reactor react to obtain H2 gas; the waste heat carried by the products in the calcination reactor and the first adsorption enhanced methane reforming reactor is recycled through the first heat exchanger, the second heat exchanger, the third heat exchanger and the fourth heat exchanger; In night mode, the high-pressure CO2 gas in the CO2 high-pressure cylinder enters the second turbine to release energy and generate electricity, and then enters the carbonation reactor to undergo a carbonation reaction with a portion of the CaO solid transported from the CaO storage tank to release heat, and the reaction products provide heat for the methane steam reforming reaction; at the same time, the remaining CaO solid transported from the CaO storage tank directly enters the second adsorption enhanced methane reforming reactor to participate in the reaction; in addition, the electric energy generated by the first turbine and the second turbine is used to supplement the heat source of the second adsorption enhanced methane reforming reactor through electric heating to enable the reaction to proceed completely.

2. The scheduling hydrogen production system of coupling solar energy storage and adsorption enhanced methane steam reforming according to claim 1 is characterized in that: In the daytime mode, the CO2 gas produced by the calcination reactor enters the first heat exchanger to exchange heat with the room temperature liquid water input into the system, so that it forms water vapor and enters the first adsorption enhanced methane reforming reactor. Then the CO2 gas continues to enter the fourth heat exchanger to exchange heat with the CH4 gas input into the system.

3. The scheduling hydrogen production system of coupling solar energy storage and adsorption enhanced methane steam reforming according to claim 1 is characterized in that: In night mode, CaO and CO2 gases in the carbonation reactor react to release heat, which is carried out of the carbonation reactor in the form of sensible heat by the product CaCO3 solid and the remaining CO2 gas of the reaction. After separation by the third gas-solid separator, the heat released by the carbonation reaction is transferred to the H2O input into the system through the seventh heat exchanger and the eighth heat exchanger respectively, providing heat for the methane steam reforming reaction, and then stored in the CaCO3 storage tank and the CO2 high-pressure gas cylinder respectively.

4. The scheduling hydrogen production system of coupling solar energy storage and adsorption enhanced methane steam reforming according to claim 1 is characterized in that: The CaO solid generated by calcination in the calcination reactor is stored in the CaO storage tank and used for the first adsorption enhanced methane reforming reaction in a ratio of 7:2; the CaO solid in the CaO storage tank is used for carbonation reaction and for the second adsorption enhanced methane reforming reaction in a ratio of 3:

2.

5. The scheduling hydrogen production system of coupling solar energy storage and adsorption enhanced methane steam reforming according to claim 1 is characterized in that: The storage module includes a CaCO3 storage tank, a CaO storage tank, a CO2 high-pressure gas cylinder, a cooler and a compressor; one inlet of the CaCO3 storage tank is indirectly connected to the outlet of the carbonation reactor via the third gas-solid separator and the eighth heat exchanger in sequence, the other inlet of the CaCO3 storage tank is indirectly connected to the outlet of the second adsorption enhanced methane reforming reactor via the fourth gas-solid separator, the ninth heat exchanger, the fifth heat exchanger and the sixth heat exchanger in sequence, and the CaCO3 storage tank outlet is connected to the top inlet of the calcination reactor via the second heat exchanger; the CaO storage tank inlet is indirectly connected to the outlet of the carbonation reactor via the first gas-solid separator and the first diverter in sequence, and the CaO storage tank outlet is respectively connected to the lower inlet of the carbonation reactor and the upper inlet of the second adsorption enhanced methane reforming reactor via the second diverter; the cooler outlet is connected to the compressor inlet, the compressor outlet is connected to one of the inlets of the CO2 high-pressure gas cylinder, and the CO2 high-pressure gas cylinder outlet is connected to the second turbine via the sixth heat exchanger and the eleventh heat exchanger in sequence.

6. The scheduling hydrogen production system of coupling solar energy storage and adsorption enhanced methane steam reforming according to claim 1 is characterized in that: The reaction medium in the calcination reactor is a solid calcium carbonate-based material; the reaction medium in the carbonation reactor is a solid calcium oxide-based material and carbon dioxide gas; the reaction medium in the first adsorption enhanced methane reforming reactor and the second adsorption enhanced methane reforming reactor is methane gas, liquid water and solid calcium oxide particles, and the catalyst loaded in the reactor is a Ni-based catalyst.

7. The scheduling hydrogen production system of coupling solar energy storage and adsorption enhanced methane steam reforming according to claim 6 is characterized in that: The solid calcium carbonate-based material is solid calcium carbonate particles; the solid calcium oxide-based material is solid calcium oxide particles.

8. The scheduling hydrogen production system of coupling solar energy storage and adsorption enhanced methane steam reforming according to claim 1 is characterized in that: When there is sufficient solar energy during the day, the first adsorption enhanced methane reforming reactor uses solar energy as a heat source. When there is no solar energy at night, the second adsorption enhanced methane reforming reactor uses the heat released by the carbonation reactor as a heat source.

9. The dispatching hydrogen production system for coupling solar energy storage and adsorption enhanced methane steam reforming according to any one of claims 1 to 8, characterized in that: The sum of the solar input powers of the calcination reactor and the first adsorption enhanced methane reforming reactor is 100MW; the temperature of the calcination reactor is 900°C and the pressure is 1 bar; the ratio of CH4:H2O in the first adsorption enhanced methane reforming reactor and the second adsorption enhanced methane reforming reactor is 1:2 by volume, the reaction temperature is 650°C and the reaction pressure is 1 bar.

10. The scheduling hydrogen production system of coupling solar energy storage and adsorption enhanced methane steam reforming according to claim 9 is characterized in that: The storage temperature in the CaO storage tank is 700°C; the storage pressure in the CO2 high-pressure cylinder is 75 bar.

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