CN114634160A - Full-flow method and device for thermochemical zinc-sulfur-iodine cycle coupling methane hydrogen production - Google Patents
Full-flow method and device for thermochemical zinc-sulfur-iodine cycle coupling methane hydrogen production Download PDFInfo
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Abstract
The invention discloses a full-flow method and a device for thermochemical hydrogen production by coupling zinc-sulfur-iodine circulation with methane, belonging to the technology of hydrogen production by coupling zinc-sulfur-iodine circulation with methane. The invention sequentially uses high-temperature gas generated by methane combustion as H of sulfur iodine circulation2SO4The decomposition and HI decomposition provide heat, the high-temperature gas is finally externally supplied with saturated steam, ZnI through a heat exchanger2‑CO2High temperature solid mixture and H in reaction column2SO4The heat of the high-temperature gas generated by decomposition is supplied to saturated steam through the heat exchanger, so that the energy cascade utilization of the process and the system is realized. The invention fully utilizes the heat of methane pure oxygen combustion without external heat supply to realize hydrogen production from methane and simultaneously has no CO2For the purpose of discharge, and is free of H2And CO separationAnd (5) problems are solved. The invention introduces solid ZnO and synthesizes ZnI2，ZnI2Then with CO2The reaction of ZnO and CO is realized, and the internal circulation of ZnO is realized. Compared with the traditional method for circularly preparing hydrogen by using sulfur and iodine, the total waste heat recovery rate of the invention can be improved to more than 65%.
Description
Technical Field
The invention relates to a technology for hydrogen production by coupling zinc-sulfur-iodine circulation with methane, belongs to the technical field related to hydrogen production by thermal circulation, and particularly relates to a full-flow method and a full-flow device for hydrogen production by coupling thermochemical zinc-sulfur-iodine circulation with methane.
Background
With the rapid increase of global economy and the massive utilization of fossil fuels, global warming is an important environmental problem which people have to face at present, and low carbon development becomes a common consensus of all countries. In order to cope with global warming climate problems, various countries have raised targets for carbon dioxide emission reduction. To solve the problem fundamentally, developing and utilizing new energy and renewable energy is a feasible way according with the development trend. The hydrogen energy is one of the cleanest energy sources, and not only is the hydrogen itself non-toxic and harmless, but also the product in the utilization process is only water, and no pollutants such as carbon dioxide and the like are discharged. The energy density of the hydrogen energy is large, and the conversion efficiency is high. Besides being used as an energy source, hydrogen is an important chemical raw material. More than half of the hydrogen is used in the important chemical processes of ammonia synthesis, petroleum cracking and the like in the world every year. Hydrogen is a secondary energy source and needs to be produced by a primary energy source. The traditional Sulfur Iodine (SI) cycle was first proposed by the American atomic energy (General Atomics) company in the 1970 s and consisted essentially of a three-step reaction:
SO2 + 2H2O +I2 = H2SO4 + 2HI （85℃）
2H2SO4 = 2SO2 +2H2O + O2 （850℃）
2HI = H2 + I2 (450℃)。
the zinc-sulfur-iodine circulating system is added with ZnI2Synthesis and ZnI2-CO2The reaction step comprises the following chemical reactions:
ZnO + 2HI = H2O + ZnI2
ZnI2 + CO2 = ZnO + I2 + CO （>800℃）。
the zinc-sulfur-iodine circulating system has the following general reactions:
H2O + CO2 = CO + H2 +O2。
the zinc-sulfur-iodine circulating system comprises four subsystems, namely a Bunsen reaction subsystem and H2SO4Decomposition subsystem, HI decomposition subsystem, ZnI2And (4) subsystems. First, sulfur dioxide and iodine react with excess water in a Bunsen reaction to form a mixed solution of sulfuric acid and hydroiodic acid. Under the condition of excessive iodine, the solution can spontaneously generate liquid-liquid stratification. The upper light phase solution is a sulfuric acid phase, mainly a sulfuric acid solution. The lower heavy phase is the hydroiodic acid phase (HIx) and will also contain small amounts of sulfuric acid impurities. Since the separated HIx solution contains impurities, and the impurities have a great influence on the subsequent process, the purification treatment of the acid solution is required. After purification, the HIx phase solution needs to be concentrated to increase the HI concentration. Rectifying and separating by a conventional rectifying tower, allowing the tower bottom residue to be high-concentration HI solution, then introducing into an HI decomposition reactor to decompose into hydrogen and iodine elementary substances at about 450 ℃, and introducing unreacted HI gas into ZnI2Subsystem, first of all reacting with ZnO to synthesize ZnI2Synthetic ZnI2With CO2Reaction at 800 deg.C to form ZnO, CO and I2. ZnO returns again to react with HI to generate ZnI2。H2SO4The phases are similar to the operation of the HIx phase, and after concentration, the H phase is introduced2SO4Decomposition of the reactor to SO2、O2And H2O, thereby forming a complete closed loop. Under the condition of an external proper heat source, only H needs to be continuously added2O and CO2H can be generated2、O2And CO. Meanwhile, the whole system can avoid the problem of hydrogen-oxygen separation, and the separation of CO belongs to gas-solid separation and is easy to operate. However, the traditional zinc-sulfur-iodine circulating hydrogen production system needs a high-temperature environment, has extremely high requirements on stable and high-quality heat sources, and causes energy waste due to huge temperature difference among units. At the same time, continuous input of high-purity CO is required2But, however, doIs the existing CO2The cost and energy consumption of the trapping technology are both at a high level. Therefore, the traditional zinc-sulfur-iodine circulating hydrogen production system is limited by a heat source place and high in cost, and cannot be popularized and applied on a large scale.
The current published technical and literature documents are studied on the thermochemical cycle hydrogen production and methane reforming hydrogen production processes, wherein patent CN108821315A discloses a thermochemical cycle mineralization of CO2Simultaneous decomposition of H2O system H2Method and apparatus for recycling hydrogen production with CO2Mineralization is organically combined, but the HI solution is concentrated by an electrodialysis method, so that the requirement on the corrosion resistance of an electrode material is extremely high, and the manufacturing cost is high; the electrolytic cell is limited in volume, so that large-scale industrial application is difficult to realize, and meanwhile, the problem of the source of a high-temperature heat source is not solved, so that industrial site selection is greatly limited, and specific implementation equipment is lacked. Patent CN102583239B provides a thermochemical cyclic decomposition of CO2And H2O to CO and H2The method and the device realize CO2The purposes of emission reduction and hydrogen production are achieved, but the highest heat source temperature (less than 900 ℃) is high in requirement, the heat source is required to be combined with other heat sources in various forms such as solar energy and nuclear energy, the site selection is greatly limited, the safety is greatly challenged, and the existing CO has the advantages that2The commercial application of capture technology still faces economic problems due to its high cost and energy consumption. Patent CN108715438A discloses thermochemical cycle mineralization of CO2Simultaneous decomposition of H2O system H2Coproduction of H2SO4Method of innovatively mixing CO2The mineralization technology is organically combined with the thermochemical sulfur-iodine open-loop circulating water decomposition for hydrogen production, and CO is mineralized and fixed under mild reaction conditions2Simultaneous production of H with high added value2And H2SO4However, it requires continuous replenishment of large amounts of SO2And does not address the source of high temperature heat sources. The patent CN102464299B provides a method for producing hydrogen by reforming methane steam with a fluidized bed, which effectively protects the activity of a catalyst for producing hydrogen by reforming and simplifies the process flow, but the methane steam is heavyThe whole hydrogen production is a strong heat absorption process, needs to provide a large amount of heat from the outside in the presence of a catalyst and is accompanied by CO2Emission, but also H2And the separation of CO. CN101559924B proposes a hydrogen production process by methane steam reforming, wherein methane, steam and an adsorbent are mixed in a mixer and then enter a reactor for reaction, and a catalyst is arranged in the reactor. The reacted gas and the adsorbent leave the reactor to be separated, part of the separated adsorbent is calcined and regenerated, the other part of the adsorbent is removed and supplemented with an equal amount of fresh adsorbent, and the fresh adsorbent and the adsorbent from the regenerator enter the mixer to be mixed together, so that continuous operation and separation of the catalyst and the adsorbent are realized, but the fresh adsorbent needs to be continuously supplemented, a large amount of heat needs to be provided from the outside, and the CO is accompanied by2And (4) discharging.
The thermochemical cycle hydrogen production process has high hydrogen production efficiency and no CO2And the discharge is beneficial to carbon neutralization, so that the thermochemical cycle is expected to be a clean, economic and sustainable large-scale hydrogen production method. However, the traditional thermochemical cycle process is limited by a high-temperature heat source, and cannot be popularized on a large scale; and from H2SO4High temperature SO generated in the decomposition tower2,O2The mixed gas must be cooled before entering the Bunsen reaction tower, and the process causes energy waste. The methane hydrogen production technology is mature and low in price, but the methane hydrogen production technology needs to consume a large amount of external energy in the traditional reforming process and is accompanied by CO2And H is present2And the separation of CO.
Disclosure of Invention
The invention aims to provide a full-flow method and a full-flow device for thermochemical zinc-sulfur-iodine cycle coupling methane hydrogen production, which do not contain CO2And (3) discharging and CO-producing hydrogen and CO, avoiding the problem of separation of hydrogen and CO, and simultaneously utilizing a high-temperature mixture generated by the heat exchanger to supply saturated steam to the outside so as to improve the heat efficiency of the system.
The technical scheme of the invention is as follows:
the invention provides a full flow method for thermochemical zinc-sulfur-iodine cycle coupling methane hydrogen production, which comprises the following steps:
the iodine-containing liquid and water in the Bunsen premixing tank are fed into a Bunsen reaction tower, reaction feeding mixed gas enters the Bunsen reaction tower from the side surface of the Bunsen reaction tower to react with the iodine-containing liquid, reaction liquid obtained by the reaction is fed into a liquid-liquid separation tower, and when a HIx phase and an H phase are reacted2SO4After phase separation, removing impurities from the HIx phase by an HIx purification tower, concentrating by an HI rectifying tower, and then entering an HI decomposition tower; h2SO4Is sent to H2SO4Concentrated in a low-pressure flash tank and enters H2SO4A decomposition tower;
high temperature CO produced by methane pure oxygen combustion2And H2The O-gas mixture is fed to H2SO4The decomposing tower heats the inner tower plate; warp H2SO4H concentrated by low-pressure flash tank2SO4Solution from H2SO4Spraying from the top of the decomposition tower, contacting with high temperature tower plate in the descending process, and performing decomposition reaction to generate SO2,O2And H2O, containing O2,SO2And H2The high-temperature mixed gas of O is returned to the Bunsen reaction tower as reaction feed mixed gas after heat exchange by a heat exchanger;
high temperature CO2And H2Mixed gas of O leaving H2SO4Feeding the tower plate inside the decomposing tower into a HI decomposing tower to heat the tower plate inside; spraying the concentrated HI solution from the top of the HI decomposition tower, contacting with high temperature tower plate in descending process, and performing decomposition reaction to generate H2And I2；H2The undecomposed HI gas and iodine vapor are then fed to a first condensing tower, and H mixed with the gas2O, HI and I2The hydrogen is washed and removed to obtain hydrogen, and the hydrogen is washed by NaOH and then is output as commodity gas; part of the iodine-containing liquid at the bottom of the first condensing tower is pressurized again and conveyed to the top of the first condensing tower for spraying, and part of the iodine-containing liquid leaves the first condensing tower and enters ZnI2A synthesis tower; high temperature CO2And H2The O mixed gas leaves a tower plate inside the HI decomposition tower and enters a heat exchanger for heat exchange and condensation, condensed water is sent to a Bunsen premixing tank for recycling, and CO2Gas access to ZnI2-CO2The reaction tower is used as a raw material;
ZnI2the synthesis tower utilizes HI in iodine-containing liquid and pre-filled ZnO solid to synthesize ZnI2；ZnI2Separating the liquid-solid mixture obtained by the reaction in the synthesis tower by a microporous filter, wherein iodine-containing liquid is sent to a second condensation tower for spraying, the sprayed iodine-containing liquid is sent to a Bunsen premixing tank for recycling, and the solid mixture ZnI in the microporous filter2And unreacted ZnO into ZnI2-CO2Reaction column, ZnI2With CO2React and externally supply CO and ZnI2-CO2Returning ZnO and unreacted materials generated in the reaction tower to ZnI2A synthesis tower.
The invention also provides a thermochemical zinc-sulfur-iodine cycle coupling methane hydrogen production full-flow device for implementing the method, which comprises a Bunsen premixing tank, a Bunsen reaction tower, a liquid-liquid separation tower, an HIx purification tower, an HI rectification tower and an H2SO4Low-pressure flash drum, first condensing tower, second condensing tower, HI decomposing tower and H2SO4A decomposition tower, a plurality of NaOH washing tanks, a first heat exchanger, a second heat exchanger, a third heat exchanger and ZnI2Synthesis column, ZnI2-CO2Reaction tower, microporous filter, CH4A combustion chamber and an oxygen storage tank;
the Bunsen reaction tower is provided with at least two gas inlets, a liquid inlet, a gas outlet and a liquid outlet; an outlet of the Bunsen premixing tank is connected with a liquid inlet of the Bunsen reaction tower, a liquid outlet of the Bunsen reaction tower is connected with an inlet of the liquid-liquid separation tower, a gas outlet is connected with the NaOH washing tank, two gas inlets are respectively connected with the HIx purification tower and the first heat exchanger, and an outlet of the NaOH washing tank is connected with the oxygen storage tank;
h of liquid-liquid separation column2SO4Phase outlet connection H2SO4Bottom spray inlet of low pressure flash tank, H2SO4The top gas outlet of the low-pressure flash tank is connected with a fan through a pipeline to discharge water vapor, and the bottom liquid outlet is connected to the H2SO4Spray inlet at the top of the decomposition column, H2SO4A decomposed gas outlet of the decomposition tower is connected to one gas inlet of the Bunsen reaction tower after passing through the first heat exchanger through a pipeline;
the HIx phase outlet of the liquid-liquid separation tower is connected with the bottom spraying inlet of the HIx purification tower; a liquid outlet of the HIx purification tower is connected with a bottom spraying inlet of the HI rectification tower, and a gas outlet is connected with the other gas inlet of the Bunsen reaction tower; a gas outlet at the top of the HI rectifying tower is connected with a fan through a pipeline to discharge water vapor, a liquid outlet at the bottom of the HI rectifying tower is connected with a top spraying inlet of the HI decomposing tower, and an iodine-containing mixed gas outlet of the HI decomposing tower is connected with a first condensing tower;
the bottom of the first condensing tower is connected with an iodine-containing liquid outlet ZnI2Synthetic tower, ZnI2The synthesis tower also has one and ZnI2-CO2Inlet to the reaction column, ZnI2The bottom outlet of the synthesis tower is connected with a microporous filter; the iodine-containing liquid outlet of the microporous filter is connected to the top spraying inlet of the second condensing tower, and the solid-phase mixture outlet of the microporous filter is connected to the ZnI2-CO2A reaction tower;
ZnI2-CO2the mixed gas outlet of the reaction tower is connected to a second condensing tower, ZnI2-CO2The high-temperature solid mixture outlet of the reaction tower is connected to ZnI after heat exchange through a third heat exchanger by a pipeline2A synthesis tower; ZnI2-CO2The reaction tower is also provided with CO2An inlet; an iodine-containing liquid outlet of the second condensation tower is connected with a Bunsen premixing tank;
CH4the oxygen inlet of the combustion chamber is connected with an oxygen storage tank, CH4The high-temperature gas outlet of the combustion chamber passes through the pipeline and sequentially passes through the H2SO4Feeding the tower plates inside the decomposition tower and the HI decomposition tower into a second heat exchanger for heat exchange, and introducing CO of the second heat exchanger2Outlet connection ZnI2-CO2CO of reaction tower2An inlet; and a condensate water outlet of the second heat exchanger is connected with a Bunsen premixing tank.
According to a preferred embodiment of the present invention, said H2SO4The decomposing tower is internally provided with a tower plate structure which is formed by arranging a plurality of inclined tower plates along the height direction of the tower, the inner cavity of the tower plate structure is used as a high-temperature gas flow passage, each inclined tower plate is at a set angle with the horizontal plane, and the bottom end of the inclined tower plate above and the adjacent inclined tower plate below are arrangedThe top ends of the high-temperature gas channels are positioned at the same side, the high-temperature gas channels of the adjacent tower plates are communicated with each other, and the lower end of the tower plate surface of each inclined tower plate is provided with a hole for the undecomposed sulfuric acid solution to enter the surface of the next inclined tower plate.
According to the preferable scheme of the invention, a tower plate structure formed by arranging a plurality of inclined tower plates along the height direction of the HI decomposition tower is arranged in the HI decomposition tower, the inside of the tower plate structure is hollow and used as a high-temperature gas flow passage, each inclined tower plate forms a set angle with the horizontal plane, the bottom end of the upper inclined tower plate and the top end of the adjacent lower inclined tower plate are positioned at the same side, the high-temperature gas flow passages of the adjacent tower plates are communicated with each other, and the surface of the tower plate of each inclined tower plate is provided with a hole for allowing the undecomposed HI solution to enter the surface of the next inclined tower plate.
The invention considers the pure oxygen combustion of methane, has the advantages of high theoretical flame temperature, small equipment size and the like, and is an efficient energy-saving combustion technology, so that the high-temperature environment required by the whole zinc-sulfur-iodine system can be provided by the pure oxygen combustion of methane, and other substances can be recycled.
CH4Pure oxygen combustion is as follows:
CH4 + 2O2 = 2H2O +CO2。
the invention organically combines the zinc-sulfur-iodine circulating hydrogen production and the methane pure oxygen combustion, and the chemical total reaction is as follows:
CH4 + O2 = H2 +H2O +CO。
compared with the traditional process and device for preparing hydrogen by thermochemical iodine sulfide, the method solves the problem of site selection of high-temperature heat sources (nuclear energy, solar energy and the like), and has a prospect of wide application in a large scale. Compared with the traditional methane reforming hydrogen production process, the invention fully utilizes the heat of pure oxygen combustion of methane without external heat supply to realize hydrogen production of methane and simultaneously without CO2Purpose of discharge, and no H2And CO separation problems. Meanwhile, the high-temperature gas generated by the methane combustion chamber is sequentially H2SO4The decomposition and HI decomposition provide heat, and finally saturated steam, ZnI, is supplied outside through a heat exchanger2-CO2High temperature solid mixture and H in reaction column2SO4The heat of the high-temperature gas generated by decomposition is supplied to saturated steam through the heat exchanger, so that the energy cascade utilization of the process and the system is realized. The invention introduces solid ZnO and synthesizes ZnI2，ZnI2Then with CO2The reaction of ZnO and CO is realized, and the internal circulation of ZnO is realized. The iodine-containing liquid at the bottom of the condensing tower returns to the premixing tank again for recycling, and compared with the traditional method for circularly preparing hydrogen by using sulfur and iodine, the total waste heat recovery rate of the invention can be improved to more than 65%.
Drawings
FIG. 1 is a schematic flow diagram of a process for producing hydrogen by sulfur-iodine cycle according to the present invention;
wherein: 1-premixing tank, 2-Bunsen reaction tower, 3-NaOH washing tank, 4-first heat exchanger and 5-H2SO4Decomposing column, 6-liquid separating column, 7-H2SO4Low-pressure flash tank, 8-HIx purification tower, 9-HI rectification tower, 10-, HI decomposition tower, 11-first condensation tower, 12-ZnI2Synthesis column, 13-Millipore Filter, 14-ZnI2-CO2Reaction tower, 15-second condensing tower, 16-pressure pump, 17-blower, 18-oxygen storage tank, 19-CH4Combustion chamber, 20-second heat exchanger; 21-a third heat exchanger; A-HIx phase liquid, B-H2SO4Phase liquid, C-SO2、O2、H2High temperature mixed gas of O, D-SO2、O2And H2O gas-liquid mixture, E-steam, F-oxygen, G-concentrated HI solution, H-H2、HI、H2O and I2Mixed gas, I-liquid-solid mixture, J-iodine-containing liquid, K-hydrogen, L-ZnO and ZnI2Mixture, M-CO2N-CO, HI and I2High temperature mixed gas, O-CO gas, P-water, Q-H2S gas, R-concentrated sulfuric acid, S-HI solution, T-high temperature CO2And H2Mixed gas of O and U-cold water.
FIG. 2 is HI decomposition column and H2SO4Detail diagram of the tower plate structure inside the decomposition tower.
Detailed Description
The technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, and the specific embodiments described herein are only used for explaining the present invention, but the scope of the present invention is not limited to the embodiments.
As shown in fig. 1, the thermochemical zn-s-i-o cycle coupling methane hydrogen production complete flow apparatus provided in this embodiment mainly includes a premixing tank 1, a Bunsen reaction tower 2, a liquid-liquid separation tower 6, a HIx purification tower 8, a HI rectification tower 9, and an H rectification tower2SO4Low-pressure flash drum 7, first condensing tower 11, second condensing tower 15, HI decomposing tower 10 and H2SO4 A decomposition tower 5, a plurality of NaOH washing tanks 3, a first heat exchanger 4, a second heat exchanger 20, a third heat exchanger 21 and ZnI2Synthesis column 12, ZnI2-CO2Reaction tower 14, microporous filter 13, CH4 A combustion chamber 19 and an oxygen storage tank 18.
Liquid phase mixture (HI, I) in Bunsen reaction column 22And water) from premix tank 1, gas phase mixture (SO)2、O2And H2O mixture) from H2SO4Decomposing tower 5 (H)2SO4The gas phase mixture generated by the decomposing tower 5 enters the Bunsen reaction tower after heat exchange by the first heat exchanger 4). Oxygen is discharged from the top of the Bunsen reaction tower, washed by a NaOH washing tank 3 and stored in an oxygen storage tank for pure oxygen combustion of methane. The operating environment of the Bunsen reaction tower 2 is normal pressure of 70-90 ℃, the reaction is spontaneous exothermic reaction, and I is remained in the tower after the reaction is finished2、H2SO4HI and H2A liquid phase mixture of O.
The reaction liquid after the reaction in the Bunsen reaction tower 2 enters a liquid-liquid separation tower 6 for H2SO4Phase and HIx phase separation on standing.
H in the liquid-liquid separation column 62SO4The phase enters H from a discharge port on the side surface of the tower2SO4In a low-pressure flash tank 7, H2SO4The operating environment of the flash tank 7 is 0.2-0.5bar, 60-80 ℃, and water is quickly vaporized and separated. Warp H2SO4H concentrated by flash tank 72SO4The solution is pressurized by a pressurizing pump 16 and then discharged from the reactor H2SO4The top of the decomposition tower 5 (the operating environment is normal pressure 1000-And (5) spraying. H2SO4The inside column plate structure (figure 2) that is equipped with of decomposition tower, the inside cavity of column plate structure is as the high temperature gas runner, the contained angle of every column plate and horizontal plane is 25 degrees (this angle is the best angle of guaranteeing that sulphuric acid solution has sufficient dwell time and can be along the downward free flow of column plate at high temperature column plate), the bottom of top column plate is located same one side and communicates each other with the top of adjacent below column plate, the high temperature gas runner of adjacent column plate communicates each other promptly, set up the rectangle hole that supplies the sulphuric acid solution of undecomposed to get into next layer slope column plate surface on the column plate lower extreme position of every slope column plate. H2SO4The high temperature gas flow channel inside the tower plate of the decomposition tower flows the high temperature from the methane combustion chamber>1500℃）CO2And H2Mixed gas of O, and the tower plate has certain temperature (1000 ℃ C. and 1200 ℃ C.). The sulfuric acid solution sprayed from the top falls to a high-temperature column plate, flows along the column plate under the action of gravity, and is subjected to decomposition reaction under the action of a catalyst, the undecomposed sulfuric acid solution falls to the next column plate through a rectangular hole on the surface of the column plate, continues to flow freely on the surface of the column plate, is subjected to decomposition reaction, and sequentially reciprocates, and in the whole process, the high-temperature gas and the sulfuric acid have independent channels and are not in contact with each other. H2SO4High-temperature mixed gas SO generated by decomposition of the decomposition tower2,O2And the water leaves from the top of the tower and enters a first heat exchanger 4 to exchange heat with cold water, and saturated steam is supplied to the outside.
The HIx phase is discharged from the bottom of the liquid-liquid separation tower 6 and flows into the HIx purification tower 8, and is sprayed and enters the bottom of the HIx purification tower 8, the operating environment of the HIx purification tower 8 is 140 ℃ at normal pressure and 200 ℃, and the gas phase mixture discharged from the top of the HIx purification tower 8 is returned to the Bunsen reaction tower 2 through a fan 17.
The HI solution from the HIx purification column 8 is sprayed from the bottom into the HI rectification column 9, concentrated under the normal pressure of 140 ℃. about.200 ℃, pressurized by the pressurizing pump 16 and sprayed from the top into the HI decomposition column 10. The operation environment of the HI decomposition tower 10 is normal pressure of 450-600 ℃, a tower plate structure (figure 2) is arranged in the HI decomposition tower, and the tower plate structure and the H of the HI decomposition tower2SO4The column plate structures of the decomposing columns are the same, and the interiors of the column plate structures are hollowThe high-temperature gas flow channels are formed, the included angle between each tower plate and the horizontal plane is 25 degrees (the angle is the optimal angle which ensures that the HI solution has enough residence time on the high-temperature tower plates and can freely flow downwards along the tower plates), the bottom end of the upper tower plate and the top end of the adjacent lower tower plate are positioned on the same side and are communicated with each other, namely, the high-temperature gas flow channels of the adjacent tower plates are communicated with each other, and the lower end of the tower plate surface of each inclined tower plate is provided with a rectangular hole for allowing the undecomposed HI solution to enter the surface of the next inclined tower plate. Flowing from H in a high-temperature gas channel inside a tower plate of the HI decomposition tower2SO4High temperature CO of decomposition column 52And H2O mixed gas (900 ℃ C. and 1100 ℃ C.) to make the tower plate have the temperature (450 ℃ C. and 600 ℃ C.). And after falling to a high-temperature tower plate, the top-sprayed HI solution flows along the tower plate at a low speed under the action of gravity and undergoes decomposition reaction under the action of a catalyst, the undecomposed HI solution falls to the next layer of tower plate through the rectangular holes on the surface of the tower plate and continues to flow on the surface of the tower plate and undergo decomposition reaction, and the steps are repeated in sequence, wherein in the whole process, the high-temperature gas and the HI solution have independent channels and are not in contact with each other. High temperature gas mixture (H) decomposed by HI decomposition tower 102,I2) And unreacted HI gas exits from the top of the column into first condensation column 11.
The iodine-containing liquid in the first condensation tower 11 is sprayed from the top and meets the high-temperature gas from the HI decomposition tower 10, and the HI gas and I2In the dissolved iodine-containing liquid, a part of the iodine-containing liquid at the bottom of the first condensing tower 11 is recycled to the top of the tower for spraying, and the rest enters ZnI2In the synthesis column 12. The hydrogen leaves from the top of the first condensing tower 11 and is collected after being washed by another NaOH washing tank 3.
Iodine-containing liquid from the first condensation column 11 and liquid from ZnI2-CO2ZnI in ZnO in reaction column 142Reaction in the synthesis column 12, ZnI2The operation environment of the synthesis tower 12 is 30-40 ℃ under normal pressure, and after the reaction is finished, the mixture in the tower enters the microporous filter 13 from the bottom of the tower. Solid phase mixture (ZnO, ZnI) filtered by microporous filter 132) Is sent to ZnI2-CO2 A reaction tower 14 for delivering the filtered iodine-containing liquidSpraying to a second condensing tower 15.
ZnI2-CO2The working environment in the reaction tower 14 is normal pressure 1000-1300 ℃, and the high-temperature CO generated in the methane combustion chamber 192And H2The O mixed gas passes through H in sequence2SO4 Decomposing tower 5 and HI decomposing tower 10, and finally reaching second heat exchanger 20, after heat exchange, condensing water vapor into liquid water and returning to premixing tank 1, and returning CO2Then enters ZnI through the side surface of the tower2-CO2Reaction column 14, ZnI from microporous filter 132Reaction of ZnI2-CO2Gaseous products (CO and I) of the reaction column 142) The CO is discharged from the top of the tower, enters a second condensing tower 15 and is sprayed by iodine-containing liquid, and the obtained CO enters another NaOH washing tank 3 and is collected after being washed. ZnI2-CO2The high-temperature solid-phase mixture in the reaction tower 14 is discharged from the bottom of the tower, subjected to heat exchange by a third heat exchanger 21 and returned to ZnI2In the synthesis tower 12, the high-temperature solid-phase mixture is subjected to heat exchange with cold water in a third heat exchanger 21, and saturated steam is supplied to the outside of the third heat exchanger 21.
In the whole set of equipment, the high temperature generated after methane pure oxygen is combusted>1500℃）CO2And H2The mixed gas of O is H in turn2SO4The decomposition reaction and the HI decomposition reaction provide heat, and finally saturated steam is supplied outside through a second heat exchanger. ZnI2-CO2The high temperature solid mixture in the reaction column 14 and H2SO4The high-temperature mixed gas generated by the decomposing tower 5 passes through the third heat exchanger 21 and the first heat exchanger 4 respectively and then is externally supplied with saturated steam, and the premixing tank 1 temporarily stores the returned iodine-containing liquid and the water condensed by the heat exchangers.
A blower 17 is provided on a gas pipe to be supplied with a power for transportation, and a booster pump 16 is provided on a liquid pipe to be supplied with a power for transportation. The fan 17 powers the gas delivery. A booster pump 16 powers the liquid delivery.
The NaOH washing tank is used for removing acid impurities and water in the product gas.
The process steps for preparing hydrogen in the zinc-sulfur-iodine cycle by adopting the device are as follows:
premixing pot 1, BunThe sen reaction tower 2 and the liquid-liquid separation tower 6 form a Bunsen reaction and liquid-liquid two-phase separation process section, reactants enter the Bunsen reaction tower 2 to generate HI and H through spontaneous reaction at 70-90 DEG C2SO4. After the reaction is finished, the mixture enters a liquid-liquid separation tower 6 for standing, and the upper layer H2SO4The phase liquid is pumped into H2SO4In flash drum 7, the lower HIx phase liquid is fed to a HIx purification column 8.
H of the liquid-liquid separation column 62SO4The phase liquid is sprayed into the flash tank 7 from the bottom, and in the environment of 60-80 ℃ and 0.2-0.5bar, the water is quickly vaporized and exits from the top of the tower. Concentrated H2SO4The solution is gathered at the bottom of the tower and then enters H through a pump2SO4The decomposition tower 5 generates decomposition reaction under the action of 1000-1200 ℃ catalyst to generate SO2、O2And H2O，SO2、O2And H2Mixed gas of O from H2SO4The top of the decomposition tower is separated and then exchanges heat with external cold water through the first heat exchanger 4, and saturated steam is supplied to the outside of the first heat exchanger 4. The mixture after heat exchange returns to the Bunsen system again, and finally, under the action of the fan 17, oxygen enters the oxygen storage tank 18 through the NaOH washing tank 3 to be combusted by methane pure oxygen.
HI and H in HIx purification column 82SO4The Bunsen reverse reaction at 140-200 ℃ occurred as follows:
8HI + H2SO4 = H2S + 4H2O + 4I2。
generation of H2The S gas exits the top of the column and is returned to the Bunsen system to achieve H removal2SO4The purpose of the impurities. Feeding the material discharged from the bottom of the HIx purification tower 8 into a HI rectifying tower 9 for concentration, and concentrating the concentrated HI/I2The solution is sprayed from the top of the HI decomposition tower 10 to descend, and the HI decomposition reaction is carried out under the action of a catalyst at the temperature of 450-600 ℃ to prepare hydrogen:
2HI = H2 + I2。
hydrogen gas, I2And the undecomposed HI gas and water vapor enter a first condensation tower 11 and are mixed with the sprayed iodine-containing liquid in the rising processBody encounter, water vapor condensation and separation, I2And HI dissolved in the iodine containing liquid. Finally, under the action of a fan, H is separated2And the product gas is discharged from the top of the tower after being washed by NaOH. Part of iodine-containing liquid for absorbing HI gas is sent to the tower top again for spraying, and the rest part enters ZnI2In the synthesis column 12.
ZnI2Synthetic tower 12, Zn-CO2The reaction tower 14 and the microporous filter 13 constitute ZnI2And (5) a process section. The liquid-solid mixture in the microporous filter 13 enters ZnI2-CO2The reaction tower 14 reacts with CO under the action of a catalyst at the temperature of 1000 ℃ and 1300 DEG C2Carrying out reaction; the iodine-containing liquid filtered by the microporous filter 13 is sent to a second condensing tower 15 for spraying, the iodine-containing liquid at the bottom of the tower returns to the premixing tank 1, and CO leaves from the top of the tower and is output as commodity gas after being washed by NaOH.
The invention realizes the hydrogen production by fully utilizing the heat of the pure oxygen combustion of the methane without discharging CO2The high-temperature gas generated in the methane combustion chamber is sequentially H2SO4The decomposition and HI decomposition provide energy, saturated steam is supplied outside through a heat exchanger, and simultaneously ZnI2-CO2High temperature solid mixture and H in the reaction column2SO4High-temperature gas generated by decomposition is supplied with saturated steam through the heat exchanger, so that the energy cascade utilization of the process and the system is realized. The invention introduces solid ZnO and synthesizes ZnI2，ZnI2Then with CO2The reaction of ZnO and CO is generated, and the purpose of internal circulation of ZnO is achieved. The iodine-containing liquid at the bottom of the second condensing tower returns to the premixing tank again for recycling.
Example 1
The operating environment in the Bunsen reaction tower is 85 ℃, the temperature is normal pressure, and the feeding in the tower is 20mol SO2,78mol I2200mol of water. After full reaction, the mixture enters a liquid-liquid separation tower to stand for 1h for separation. After separation of the two phases, H2SO4Phase composition H2SO4 4.3 mol/kg，HI 0.5 mol/kg，I2 0.1 mol/kg，H2O27.3 mol/kg, molar ratio of impurities HI/H2SO4Is 0.12; HIx phase composition is H2SO4 0.2 mol/kg，HI 1.5 mol/kg，I2 2.4 mol/kg，H2O9.1 mol/kg, impurity molar ratio H2SO4The HI was 0.13.
H2SO4Phase mixture from H2SO4The bottom of the flash tank is sprayed, the liquid water is quickly vaporized and carried away under the environment of 70 ℃ at 0.3 bar. H2SO4Bottom H of flash tower2SO4The mass fraction reaches 85 percent. Concentrated sulfuric acid enters H2SO4The decomposition tower is subjected to decomposition reaction under the action of a catalyst at 1100 ℃, and the decomposition rate reaches over 98 percent. SO produced by decomposition2、O2And H2The molar ratio of O was about 2:2:1, the mixed gas exited from the top of the column and the exit temperature was 1100 ℃. The high-temperature mixed gas exchanges heat with external cold water in a first heat exchanger, then returns to the Bunsen reaction tower for circulation, and O obtained in the Bunsen reaction tower2And (4) washing by NaOH, and outputting to an oxygen storage tank for methane pure oxygen combustion.
The HIx phase mixture was sprayed from the bottom of the HIx purification column and reacted at 160 ℃ as follows:
by-product H2S generation H2SO4 + 8HI ＝ H2S + 4I2 + 4H2O。
Gas H2S is returned to the Bunsen reaction tower for circulation again, so that the impurity H is effectively removed2SO4Purpose of purifying the HI solution.
HI concentration at the bottom of the HIx rectifying tower reaches HI and H2The azeotropic point of O is 4.45mol/kg (57%), the concentrated HI solution enters an HI decomposition tower, and decomposition reaction is carried out under the action of a catalyst at 500 ℃, and the decomposition rate is 22%. H produced by decomposition2、I2And unreacted HI gas and water vapor exited the top of the column at an exit temperature of 500 ℃. High temperature mixed gas (H)2、I2、HI、H2O) is sent into a first condensing tower under the action of a fan, meets iodine-containing liquid sprayed at the tower top in the rising process, and water vapor is condensed and separated out to obtain HI, I2The gas is dissolved in iodine-containing liquid, the hydrogen leaves from the tower top and is washed by NaOH solution to be output as commodity gas, and the output speed is 0.45m3/h。Part of iodine-containing liquid at the bottom of the first condensing tower is sprayed and recycled from the tower top again, and the rest part is sent to ZnI2A synthesis tower.
ZnI2ZnI after reaction in the synthesis column2The ZnO mixture enters ZnI after being filtered by a microporous filter2-CO2A reaction tower for generating CO by combusting with methane pure oxygen under the action of a catalyst at 1300 DEG C2Reaction:
ZnI2 + CO2 = ZnO + I2 + CO。
formed ZnO and unreacted ZnI2Returning the solid mixture to ZnI2The synthesis tower enters the next circulation. CO and I2The mixed gas is sprayed by iodine-containing liquid in the second condensing tower, CO leaves the second condensing tower and is washed by NaOH to be output as commercial gas, and the output speed is 0.45m3H is used as the reference value. The iodine-containing liquid at the bottom of the second condensing tower is sent to a premixing tank.
The system heat balance can be known, the total waste heat recovery efficiency is 65%, and high energy utilization efficiency is realized.
Example 2
The operating environment in the Bunsen reaction tower is 85 ℃ and normal pressure, and the charging amount in the tower is 25mol of SO2,55mol I2240mol of water. After full reaction, the mixture enters a liquid-liquid separation tower to stand for 1h for separation. After separation of the two phases, H2SO4Phase composition of H2SO4 4.6 mol/kg，HI 0.2 mol/kg，I2 0.07 mol/kg，H2O27.5 mol/kg, molar ratio of impurities HI/H2SO4Is 0.05; HIx phase composition is H2SO4 0.05 mol/kg，HI 1.0mol/kg，I2 3.3 mol/kg，H2O12.4 mol/kg, impurity molar ratio H2SO4The HI was 0.05.
H2SO4Phase mixture from H2SO4Spraying from the bottom of the flash tank, wherein liquid water is quickly vaporized and carried away in an environment of 0.3bar and 70 ℃. H2SO4Bottom H of flash tower2SO4The mass fraction reaches 85 percent. Concentrated sulfuric acid enters H2SO4The decomposition tower is subjected to decomposition reaction under the action of a catalyst at 1100 ℃, and the decomposition rate reaches more than 98 percentThe above. SO produced by decomposition2、O2And H2The molar ratio of O was about 2:2:1, the mixed gas exited from the top of the column and the exit temperature was 1100 ℃. The high-temperature mixed gas exchanges heat with external cold water in a first heat exchanger, returns to the Bunsen reaction tower for circulation, and O obtained in the Bunsen reaction tower2And (4) washing by NaOH, and outputting to an oxygen storage tank for methane pure oxygen combustion.
The HIx phase mixture was sprayed from the bottom of the HIx purification column and reacted at 160 ℃ as follows:
by-product H2S generation H2SO4 + 8HI ＝ H2S + 4I2 + 4H2O。
Gas H2S is returned to the Bunsen reaction tower for circulation again, so that the impurity H is effectively removed2SO4Purpose of purifying HI solution.
HI concentration at the bottom of the HIx rectifying tower reaches HI and H2The azeotropic point of O is 4.45mol/kg (57%), the concentrated HI solution enters an HI decomposition tower, and decomposition reaction is carried out under the action of a catalyst at 500 ℃, and the decomposition rate is 22%. H produced by decomposition2、I2And unreacted HI gas and water vapour exit the top of the column at an exit temperature of 500 ℃. High temperature mixed gas (H)2、I2、HI、H2O) is sent into a first condensing tower under the action of a fan, meets iodine-containing liquid sprayed at the tower top in the rising process, and water vapor is condensed and separated out to obtain HI, I2The gas is dissolved in iodine-containing liquid, the hydrogen leaves from the tower top and is washed by NaOH solution to be output as commodity gas, and the output speed is 0.45m3H is used as the reference value. Part of the iodine-containing liquid at the bottom of the first condensation tower is sprayed and circulated from the tower top again, and the rest iodine-containing liquid is sprayed and circulated to ZnI2A synthesis tower.
ZnI2ZnI after reaction in the synthesis column2The ZnO mixture enters ZnI after being filtered by a microporous filter2-CO2A reaction tower for generating CO by pure oxygen combustion with methane under the action of a 1300 ℃ catalyst2Reaction:
ZnI2 + CO2 = ZnO + I2 + CO。
formed ZnO and unreacted ZnI2Returning the solid mixture to ZnI2The synthesis tower enters the next circulation. CO and I2The mixed gas is sprayed by iodine-containing liquid in the second condensing tower, CO leaves the second condensing tower and is washed by NaOH to be output as commercial gas, and the output speed is 0.45m3H is used as the reference value. The iodine-containing liquid at the bottom of the second condensing tower is sent to a premixing tank.
The system heat balance can be known, the total waste heat recovery efficiency is 65%, and high energy utilization efficiency is realized.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is specific and detailed, but not to be understood as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.
Claims (10)
1. A full-flow method for hydrogen production by coupling thermochemical zinc-sulfur-iodine cycle with methane is characterized by comprising the following steps:
the iodine-containing liquid and water in the Bunsen premixing tank are fed into a Bunsen reaction tower, reaction feeding mixed gas enters the Bunsen reaction tower from the side surface of the Bunsen reaction tower to react with the iodine-containing liquid, reaction liquid obtained by the reaction is fed into a liquid-liquid separation tower, and when a HIx phase and an H phase are reacted2SO4After phase separation, removing impurities from the HIx phase by an HIx purification tower, concentrating by an HI rectifying tower, and then entering an HI decomposition tower; h2SO4Is sent to H2SO4Concentrated in a low-pressure flash tank and enters H2SO4A decomposition tower;
high temperature CO produced by methane pure oxygen combustion2And H2The O-mixed gas is sent to H2SO4The decomposing tower heats the inner tower plate; warp H2SO4H concentrated by low-pressure flash tank2SO4Solution from H2SO4Spraying from the top of the decomposition tower, contacting with high temperature tower plate in the descending process, and performing decomposition reaction to generate SO2、O2And H2O, containing O2、SO2And H2The high-temperature mixed gas of O is returned to the Bunsen reaction tower as reaction feeding mixed gas after heat exchange by a heat exchanger;
high temperature CO2And H2Mixed gas of O leaving H2SO4Feeding the column plate in the decomposition tower into an HI decomposition tower to heat the column plate; spraying the concentrated HI solution from the top of the HI decomposition tower, contacting with high temperature tower plate in descending process, and performing decomposition reaction to generate H2And I2；H2The undecomposed HI gas and iodine vapor are then fed to a first condensing tower, and H mixed with the gas2O, HI and I2The hydrogen is washed and removed to obtain hydrogen, and the hydrogen is washed by NaOH and then is output as commodity gas; part of the iodine-containing liquid at the bottom of the first condensing tower is pressurized again and conveyed to the top of the first condensing tower for spraying, and part of the iodine-containing liquid leaves the first condensing tower and enters ZnI2A synthesis tower; high temperature CO2And H2The O mixed gas leaves a tower plate inside the HI decomposition tower and then enters a heat exchanger for heat exchange and condensation, condensed water is sent to a Bunsen premixing tank for recycling, and CO2Gas access to ZnI2-CO2The reaction tower is used as a raw material;
ZnI2the synthesis tower utilizes HI in iodine-containing liquid and pre-filled ZnO solid to synthesize ZnI2；ZnI2Separating the liquid-solid mixture obtained by the reaction in the synthesis tower by a microporous filter, wherein iodine-containing liquid is sent to a second condensation tower for spraying, the sprayed iodine-containing liquid is sent to a Bunsen premixing tank for recycling, and a solid mixture ZnI in the microporous filter2And unreacted ZnO into ZnI2-CO2Reaction column, ZnI2With CO2React and externally supply CO and ZnI2-CO2Returning ZnO and unreacted materials generated in the reaction tower to ZnI2A synthesis tower.
2. The full-flow method for thermochemical zinc-sulfur-iodine cycle coupling hydrogen production from methane as claimed in claim 1, wherein CO generated after pure oxygen combustion of methane2And H2The temperature of the O high-temperature mixed gas is more than 1500 ℃;
into H2SO4CO of column plate inside decomposing tower2And H2The temperature of the O high-temperature mixed gas is more than 1500 ℃, and the mixed gas leaves H2SO4CO of column plate inside decomposing tower2And H2The temperature of the O high-temperature mixed gas is 1000-2And H2The temperature of the O high-temperature mixed gas is 900-1100 ℃, and the CO leaving the tower plate inside the HI decomposition tower2And H2The temperature of the O high-temperature mixed gas is 450-600 ℃.
3. The full flow process for hydrogen production from methane by thermochemical zinc-sulfur-iodine cycle coupling as claimed in claim 1, wherein said Bunsen reaction tower, liquid-liquid separation tower, HIx purification tower, HI rectification tower, first condensation tower, second condensation tower, HI decomposition tower, H2SO4Decomposing tower, ZnI2Synthesis column and ZnI2-CO2The tower pressure of the reaction tower is normal pressure; h2SO4The pressure in the low-pressure flash tank is controlled between 0.2 and 0.5 bar.
4. The thermochemical zinc-sulfur-iodine cycle coupled methane hydrogen production full process method of claim 1 wherein the temperature of the Bunsen reaction tower is 70-90 ℃; the inlet/outlet temperature of the HIx purification tower is 140-200 ℃; the temperature of the HI rectifying tower is 140-200 ℃; the temperature of the HI decomposition tower is 450-600 ℃; h2SO4The temperature of the low-pressure flash tank is 60-80 ℃; h2SO4The temperature of the decomposition tower is 1000-1200 ℃; ZnI2-CO2The temperature of the reaction tower is 1000-1300 ℃; ZnI2The temperature of the synthesis tower is 30-40 ℃.
5. The full flow process for hydrogen production from methane by thermochemical zinc-sulfur-iodine cycle coupling as claimed in claim 1, wherein SO entering the Bunsen reaction tower2、H2O and I2The molar ratio of (1), (8-10): (2-4), returning the O in the Bunsen reaction tower2And SO2The molar flow ratio of (a) to (b) is 1: 2.
6. Thermochemical zinc-sulfur-iodine cycle coupling methane hydrogen production total flow for implementing method of claim 1The device is characterized by comprising a Bunsen premixing tank, a Bunsen reaction tower, a liquid-liquid separation tower, a HIx purification tower, a HI rectifying tower and H2SO4Low-pressure flash drum, first condensing tower, second condensing tower, HI decomposing tower and H2SO4A decomposition tower, a plurality of NaOH washing tanks, a first heat exchanger, a second heat exchanger, a third heat exchanger and ZnI2Synthesis column, ZnI2-CO2Reaction tower, microporous filter, CH4A combustion chamber and an oxygen storage tank;
the Bunsen reaction tower is provided with at least two gas inlets, a liquid inlet, a gas outlet and a liquid outlet; an outlet of the Bunsen premixing tank is connected with a liquid inlet of the Bunsen reaction tower, a liquid outlet of the Bunsen reaction tower is connected with an inlet of the liquid-liquid separation tower, a gas outlet is connected with the NaOH washing tank, two gas inlets are respectively connected with the HIx purification tower and the first heat exchanger, and an outlet of the NaOH washing tank is connected with the oxygen storage tank;
h of liquid-liquid separation column2SO4Phase outlet connection H2SO4Bottom spray inlet of low pressure flash tank, H2SO4The top gas outlet of the low-pressure flash tank is connected with a fan through a pipeline to discharge water vapor, and the bottom liquid outlet is connected to the H2SO4Spray inlet at the top of the decomposition column, H2SO4A decomposed gas outlet of the decomposition tower is connected to one gas inlet of the Bunsen reaction tower after passing through the first heat exchanger through a pipeline;
the HIx phase outlet of the liquid-liquid separation tower is connected with the bottom spraying inlet of the HIx purification tower; a liquid outlet of the HIx purification tower is connected with a bottom spraying inlet of the HI rectifying tower, and a gas outlet is connected with the other gas inlet of the Bunsen reaction tower; a gas outlet at the top of the HI rectifying tower is connected with a fan through a pipeline to discharge water vapor, a liquid outlet at the bottom of the HI rectifying tower is connected with a top spraying inlet of the HI decomposing tower, and an iodine-containing mixed gas outlet of the HI decomposing tower is connected with a first condensing tower;
the bottom of the first condensing tower is connected with an iodine-containing liquid outlet ZnI2Synthetic tower, ZnI2The synthesis tower also has one and ZnI2-CO2Inlet to the reaction column, ZnI2The bottom outlet of the synthesis tower is connected withConnecting a microporous filter; the iodine-containing liquid outlet of the microporous filter is connected to the top spraying inlet of the second condensing tower, and the solid-phase mixture outlet of the microporous filter is connected to the ZnI2-CO2A reaction tower;
ZnI2-CO2the mixed gas outlet of the reaction tower is connected to a second condensing tower, ZnI2-CO2The high-temperature solid mixture outlet of the reaction tower is connected to ZnI after heat exchange through a third heat exchanger by a pipeline2A synthesis tower; ZnI2-CO2The reaction tower is also provided with CO2An inlet; an iodine-containing liquid outlet of the second condensation tower is connected with a Bunsen premixing tank;
CH4the oxygen inlet of the combustion chamber is connected with an oxygen storage tank, CH4The high-temperature gas outlet of the combustion chamber passes through the pipeline and sequentially passes through the H2SO4Introducing the tower plates inside the decomposition tower and the HI decomposition tower into a second heat exchanger for heat exchange, wherein CO in the second heat exchanger2Outlet connection ZnI2-CO2CO of reaction tower2An inlet; and a condensate water outlet of the second heat exchanger is connected with a Bunsen premixing tank.
7. The thermochemical zinc-sulfur-iodine cycle coupling methane hydrogen production complete flow plant of claim 6, wherein said H is2SO4The inside column plate structure of constituteing is arranged along the tower height direction by a plurality of slope column plates to decomposition tower inside, the inside cavity of column plate structure is as the high-temperature gas runner, every slope column plate all personally submits the settlement angle with the level, the bottom of top slope column plate and the top of adjacent below slope column plate lie in with the high-temperature gas runner of one side and adjacent column plate intercommunication each other, set up the hole that supplies the sulfuric acid solution of non-decomposition to get into one deck slope column plate surface down on the column face lower extreme position of every slope column plate, high-temperature gas and sulfuric acid solution are contactless in the tower.
8. The full flow device for hydrogen production from methane by thermochemical zinc-sulfur-iodine cycle coupling according to claim 6, wherein a column plate structure composed of a plurality of inclined column plates arranged in the height direction of the column is provided inside the HI decomposition column, the column plate structure is hollow as a high-temperature gas flow passage, each inclined column plate is at a predetermined angle with the horizontal plane, the bottom end of the upper inclined column plate and the top end of the adjacent lower inclined column plate are located on the same side, the high-temperature gas flow passages of the adjacent column plates are communicated with each other, a hole for allowing undecomposed HI solution to enter the surface of the lower inclined column plate is provided on the column plate surface of each inclined column plate, and the high-temperature gas and HI solution are not in contact with each other in the column.
9. The full-flow device for hydrogen production from methane by thermochemical zinc-sulfur-iodine cycle coupling according to claim 7 or 8, characterized in that the included angle between the inclined tower plate and the horizontal plane is 25 °.
10. The thermochemical zinc-sulfur-iodine cycle coupling methane hydrogen production complete flow device according to claim 6, wherein a hydrogen outlet is formed in the top of the first condensing tower, and the hydrogen outlet is connected with a NaOH washing tank; a CO gas outlet is formed in the top of the second condensing tower and connected with a NaOH washing tank; the first heat exchanger, the second heat exchanger and the third heat exchanger use water as heat exchange media and supply saturated steam to the outside.
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| CN115321479A (en) * | 2022-10-11 | 2022-11-11 | 浙江百能科技有限公司 | Method and device for producing hydrogen and co-producing sulfuric acid by thermochemical zinc-sulfur-iodine cycle decomposition of water |
| CN116969416A (en) * | 2023-09-20 | 2023-10-31 | 浙江百能科技有限公司 | System and process for oxygen-enriched combustion coupled thermochemical sulfur-iodine cycle |
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