Metallurgical high-temperature waste residue sensible heat driven iodine-sulfur open-cycle hydrogen production process

Abstract

The invention belongs to the technical field of utilizing waste heat recovery to participate in thermochemical hydrogen production, and discloses an iodine-sulfur open-cycle hydrogen production process driven by sensible heat of metallurgical high-temperature waste slag. The Bunsen system is connected with the SO2 storage tank; the HI decomposition reaction device is connected with the Bunsen system; i2 generated by decomposition of the HI decomposition reaction device is put into the Bunsen system again; the H2 storage tank is communicated with the HI decomposition system; wherein the HI decomposition reaction device is provided with an injection port, and the metallurgical high-temperature waste slag is injected into the HI decomposition reaction device through the injection port; and the HI decomposition reaction device is used for carrying out HI decomposition reaction by absorbing heat of the metallurgical high-temperature waste slag. According to the invention, SO2 generated by flue gas desulfurization of a steel plant is taken as a raw material, a sulfuric acid decomposition link is avoided, meanwhile, a direct heat exchange reactor is designed, heat of metallurgical waste residues is efficiently utilized, an HI decomposition catalyst is removed, a reaction system is simplified, and the waste heat utilization rate is improved.

Description

Technical Field

[0001] This invention belongs to the field of waste heat recovery for thermochemical hydrogen production technology. Specifically, it relates to an open-circuit hydrogen production process driven by the sensible heat of metallurgical high-temperature waste slag. Background Technology

[0002] The iron and steel metallurgical process generates a large amount of high-temperature waste slag, mainly blast furnace slag and steel slag. Currently, my country's annual blast furnace slag production exceeds 300 million tons, with a slag discharge temperature of 1400-1600℃ and an enthalpy value of 1700 MJ·t. -1 Each ton of slag contains the equivalent heat released by the complete combustion of 60 kg of standard coal, making its sensible heat resources quite abundant. Currently, most enterprises do not recover this sensible heat; only a few utilize the waste heat from the slag flushing water after water quenching for heating, but their waste heat recovery rate is only about 10%. The high-quality sensible heat resources contained in hot metallurgical waste slag are not being effectively recovered and utilized. In recent years, dry granulation processes have been proposed, using air as a cooling medium and heat recovery via heat exchangers. However, heat exchange processes still exist, and due to the low thermal conductivity of high-temperature molten slag, heat exchange cannot simultaneously achieve both rate and temperature balance. Based on this, thermochemical exchange has been proposed, which utilizes endothermic chemical reaction processes to rapidly absorb heat from the slag to produce fuel, including reactions such as coal gasification, methane reforming, and methanol decomposition.

[0003] Chinese patent application number 202310176925.0 discloses a method for hydrogen production via blast furnace slag sensible heat recovery coupled with thermochemical iodine-sulfur cycle. The method utilizes the waste heat recovered from blast furnace slag to drive iodine-sulfur cycle hydrogen production, employing a dry granulation process. Air is used as the medium to recover heat from the blast furnace slag, and hot air drives the decomposition of sulfuric acid to produce SO2 for the Bunsen reaction. The HI generated in the Bunsen reaction decomposes to produce H2 at 300-500℃. The process still uses air as the heat exchange medium, which has lower thermal efficiency compared to direct heat exchange. Furthermore, the SO2 production reaction temperature from sulfuric acid decomposition is above 850℃, placing stringent requirements on equipment structure, corrosion resistance, and heating uniformity. HI decomposition requires additional catalyst filling, which is expensive, has poor stability, and is prone to poisoning and deactivation. Chinese patent application number 202210141496.9 discloses a thermochemical sulfur-iodine cycle hydrogen production method and apparatus, which optimizes sulfuric acid decomposition and the Bunsen reactor to reduce investment and energy consumption. However, its design does not consider a heat source, and the chemical reaction process is not optimized. The long process still results in heat loss and equipment complexity. Chinese patent application number 200510061121.8 discloses an open-loop iodine-sulfur cycle hydrogen production process and apparatus, proposing the roasting of sulfur-containing minerals to produce SO2 for the reaction process, avoiding the sulfuric acid decomposition step and simplifying the system. However, sulfide roasting also requires energy consumption, and the heat source is not determined in the design.

[0004] Based on the above analysis, simplifying the iodine-sulfur cycle hydrogen production process and efficiently utilizing the sensible heat of metallurgical waste slag to drive the reaction energy, thereby simultaneously achieving efficient utilization of waste heat from metallurgical waste slag and low-cost hydrogen production, is the optimal technical route to promote the recovery and utilization of waste heat resources in the steel industry and efficient and low-cost hydrogen production.

[0005] Therefore, there is an urgent need to provide a hydrogen production process for iodine-sulfur open-circuit driven by the sensible heat of metallurgical high-temperature waste slag to overcome the above problems.

[0006] In view of the above, this application is hereby submitted. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology, such as low utilization rate of waste heat from metallurgical waste slag and frequent addition of reaction catalyst. The purpose is to provide a metallurgical high-temperature waste slag sensible heat driven open-circuit iodine-sulfur cycle hydrogen production process that simplifies the iodine-sulfur cycle hydrogen production process while improving the utilization rate of waste heat from metallurgical waste slag.

[0008] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is: a hydrogen production process for iodine-sulfur open-circuit cycle driven by sensible heat from metallurgical high-temperature waste slag, comprising:

[0009] SO2 storage tank, wherein the SO2 storage tank stores SO2 gas;

[0010] The Bunsen system has its inlet connected to the outlet of the SO2 storage tank, and uses SO2 gas as one of the reaction raw materials.

[0011] The HI decomposition reactor is connected to the Bunsen system and uses HI generated by the reaction in the Bunsen system as a raw material for the decomposition reaction. The I2 generated by the decomposition in the HI decomposition reactor is reintroduced into the Bunsen system as a reaction raw material for the Bunsen system.

[0012] H2 storage tank, which is connected to the hydrogen outlet of the HI decomposition system, is used to store the H2 generated by the HI decomposition reaction device;

[0013] The HI decomposition reaction device is equipped with an injection port through which metallurgical high-temperature waste slag is injected; the HI decomposition reaction device carries out the HI decomposition reaction by absorbing the heat from the metallurgical high-temperature waste slag.

[0014] According to one embodiment of the present invention, the SO2 stored in the SO2 storage tank originates from high-concentration SO2 generated by flue gas desulfurization in a steel plant.

[0015] According to one embodiment of the present invention, the Bunsen system further includes:

[0016] Water is injected through the water inlet, with water being one of the reaction raw materials;

[0017] Iodine injection port: I2 generated by the reaction of the HI decomposition reaction device is injected into the Bunsen through the iodine injection port.

[0018] The generated H2SO4 is discharged from the Bunsen system through the sulfur discharge port.

[0019] According to one embodiment of the present invention, the HI decomposition reaction device further includes: a slag discharge port through which the heat-transferred high-temperature metallurgical waste slag is discharged from the HI decomposition reaction device.

[0020] The horizontal level of the slag discharge port is lower than the horizontal level of the injection port.

[0021] According to one embodiment of the present invention, the metallurgical high-temperature waste slag includes blast furnace slag and steel slag.

[0022] According to one embodiment of the present invention, a heat exchange tube sheet is provided inside the HI decomposition reaction device. The heat exchange tube sheet is inclined, and one end of the heat exchange tube sheet is connected to the inner wall of the HI decomposition reaction device, while the horizontal height of the other end is less than the horizontal height of the end connected to the inner wall of the HI decomposition reaction device.

[0023] HI flows from the bottom to the top of the heat exchange tube sheet for preheating and decomposition;

[0024] The high-temperature metallurgical waste slag injected into the HI decomposition reactor through the injection port is poured onto the heat exchange tube sheet.

[0025] According to one embodiment of the present invention, the heat exchange tube sheet is composed of a single heat exchange core tube arranged in a tight "S" shape.

[0026] The heat exchange core tube is filled with thermally conductive particles, and the porosity of the heat exchange core tube is 0.5.

[0027] According to one embodiment of the present invention, a plurality of heat exchange tube sheets are provided, and the plurality of heat exchange tube sheets are arranged sequentially and at intervals facing each other;

[0028] The horizontal height of the lower end of the upper heat exchanger tube sheet in two adjacent heat exchanger tube sheets is greater than the horizontal height of the upper end of the lower heat exchanger tube sheet in two adjacent heat exchanger tube sheets.

[0029] Metallurgical high-temperature waste slag injected into the HI decomposition reactor through the injection port moves sequentially from top to bottom on multiple heat exchange tube sheets.

[0030] According to one embodiment of the present invention, the angle between the heat exchange tube sheet and the horizontal plane is 10°-75°.

[0031] According to one embodiment of the present invention, four heat exchange tube sheets are provided, and the four heat exchange tube sheets are respectively a first heat exchange tube sheet, a second heat exchange tube sheet, a third heat exchange tube sheet and a fourth heat exchange tube sheet from top to bottom in terms of horizontal height;

[0032] The first heat exchanger tube sheet is connected to the third heat exchanger tube sheet, and the second heat exchanger tube is connected to the fourth heat exchanger tube, or...

[0033] The first heat exchanger tube sheet is connected to the fourth heat exchanger tube sheet, and the second heat exchanger tube is connected to the third heat exchanger tube.

[0034] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0035] 1) This invention features a simple and reliable process with low investment costs and good economic efficiency. It simplifies the process by eliminating the sulfuric acid decomposition unit in the traditional iodine-sulfur cycle hydrogen production process, significantly simplifying the process flow. Compared with existing open-loop, complex SO2 production processes, this invention uses SO2 generated from steel plant waste gas desulfurization as raw material, resulting in a substantial reduction in process equipment. Furthermore, it converts SO2 in the waste gas into sulfuric acid, achieving waste reuse and providing better economic benefits.

[0036] 2) This invention improves system thermal efficiency and significantly reduces operating energy consumption. By adopting a strategy of direct heat exchange between high-temperature metallurgical waste slag and HI, the energy conversion process is avoided. The waste heat recovery rate of blast furnace slag is increased from 10% in the traditional water quenching method to over 65%. Iodine-sulfur hydrogen production can achieve continuous and stable operation entirely by relying on the waste heat of blast furnace slag. Only water and SO2 byproducts of waste gas desulfurization need to be input to produce H2 and sulfuric acid.

[0037] 3) This invention significantly reduces the cost of hydrogen production from iodine and sulfur. The simplified process system and efficient utilization of waste heat lead to a substantial reduction in the investment and operating costs of iodine-sulfur chemical hydrogen production. In addition, the efficient heat transfer can ensure that the temperature of the HI decomposition reactor is above 500°C, enabling catalyst-free high-temperature thermal decomposition of HI. This reduces catalyst costs and effectively avoids system problems caused by catalyst deactivation. The cost of hydrogen production from iodine and sulfur can be reduced to below 3 yuan / kg H2.

[0038] 4) This invention improves HI decomposition efficiency and increases hydrogen production rate. The HI decomposition temperature is increased from 300-500℃ in the traditional iodine-sulfur method to 600-1200℃. The high temperature promotes the reaction rate, shortens the reaction time, and increases the decomposition rate. At 1200℃, the equilibrium decomposition rate can reach 63.3%, which is significantly higher than the 1% decomposition rate at 500℃ without a catalyst and 23% under the condition with a catalyst. The H2 yield is 2.5 times higher than that under the traditional condition with a catalyst.

[0039] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0040] The accompanying drawings, as part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation of the invention. Obviously, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings:

[0041] Figure 1 This is a process flow diagram of an open-circuit hydrogen production process for iodine and sulfur driven by sensible heat from metallurgical high-temperature waste slag, as described in an embodiment of the present invention.

[0042] Figure 2 This is a schematic diagram of the HI decomposition reaction device in an embodiment of the present invention;

[0043] Figure 3 This is a schematic diagram of the structural composition of the heat exchange tube sheet in an embodiment of the present invention.

[0044] Description of main components in the diagram:

[0045] 1. SO2 storage tank; 2. Bunsen system; 3. HI decomposition reaction device; 31. Heat exchanger tube sheet; 311. Heat exchanger core tube; 4. H2 storage tank; 5. Slag collector.

[0046] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0048] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0049] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0050] like Figures 1 to 3 As shown, the present invention discloses a metallurgical high-temperature waste slag sensible heat-driven iodine-sulfur open-circuit hydrogen production process, comprising:

[0051] SO2 storage tank 1, wherein SO2 storage tank 1 stores SO2 gas;

[0052] Bunsen system 2, wherein the air inlet of Bunsen system 2 is connected to the air outlet of SO2 storage tank 1, and SO2 gas is used as one of the reaction raw materials;

[0053] HI decomposition reaction device 3 is connected to Bunsen system 2 and uses HI generated by the reaction in Bunsen system 2 as raw material for decomposition reaction; the I2 generated by the decomposition of HI decomposition device 3 is reintroduced into Bunsen system 2 as a reaction raw material of Bunsen system 2.

[0054] H2 storage tank 4 is connected to the hydrogen outlet of the HI decomposition system and is used to store the H2 generated by the HI decomposition reaction device 3.

[0055] The HI decomposition reaction device 3 is equipped with an injection port through which metallurgical high-temperature waste slag is injected; the HI decomposition reaction device 3 carries out the HI decomposition reaction by absorbing the heat of the metallurgical high-temperature waste slag.

[0056] Existing technologies rely on intermediate media such as air for sensible heat recovery from waste residue, which suffers from the problem of difficulty in balancing heat exchange rate and temperature and low thermal efficiency. This invention directly injects high-temperature metallurgical waste residue into the HI decomposition reaction device through an injection port, enabling direct heat exchange between the waste residue and the reaction system without a medium. This eliminates intermediate heat transfer links such as air / water, avoids energy loss during the heat exchange process, and achieves higher sensible heat utilization, directly reducing the external energy consumption of the HI decomposition reaction.

[0057] This invention utilizes the heat of the waste residue itself (1400-1600℃) to directly meet the temperature requirements of the HI decomposition reaction (300-500℃), thereby reducing equipment investment costs; this invention directly drives HI decomposition through the sensible heat of the waste residue, increasing the reaction rate to a level that does not require high-cost catalysts, thereby reducing operating costs.

[0058] The I2 generated by HI decomposition is directly returned to the Bunsen system, forming a closed loop with the SO2 in the SO2 storage tank (unlike the high-energy-consuming process of existing technologies that require roasting of sulfur-containing minerals or decomposition of sulfuric acid to regenerate SO2). The utilization rate of sulfur and iodine media is close to 100%, reducing the energy consumption in the SO2 preparation process.

[0059] Existing technologies suffer from severe heat loss due to their "long process and multiple heat exchange stages," while this invention reduces heat loss during transmission and conversion through a short process design.

[0060] By directly utilizing the sensible heat of metallurgical waste slag, no additional cooling medium is required, reducing wastewater and dust emissions from the metallurgical waste slag cooling process at the source. High-value-added hydrogen is produced while recovering the sensible heat of the waste slag, achieving synergistic optimization of "cost reduction, efficiency improvement and emission reduction" in the metallurgical industry.

[0061] In summary, this invention, through its core design of "direct injection of metallurgical high-temperature waste slag into a HI decomposition reaction device," overcomes the bottlenecks in existing technologies such as "low efficiency of indirect heat exchange, complex equipment, and catalyst dependence," achieving multi-dimensional improvements in the utilization rate of sensible heat from waste slag, hydrogen production costs, and system stability. It provides a new technical path for waste heat recovery and low-cost green hydrogen production in the steel industry, and has significant industrial application value and environmental benefits.

[0062] In one specific embodiment of this example, the SO2 stored in the SO2 storage tank 1 originates from high-concentration SO2 generated by flue gas desulfurization in a steel plant.

[0063] More specifically, in one particular embodiment of this example, the SO2 source includes high-concentration SO2 generated after desorption by the activated carbon desulfurization device for sintering flue gas, or high-concentration SO2 generated by the hydrolysis desulfurization analysis tower for blast furnace gas.

[0064] In one specific implementation of this embodiment, the Bunsen system 2 further includes:

[0065] Water is injected through the water inlet, with water being one of the reaction raw materials;

[0066] Iodine injection port: I2 generated by the reaction in HI decomposition reaction device 3 is injected into the Bunsen through the iodine injection port.

[0067] The generated H2SO4 is discharged from the Bunsen system 2 through the sulfur discharge port.

[0068] By introducing high-concentration SO2 gas and water from SO2 storage tank 1 into the Bunsen reaction system, the SO2 reacts with I2 at 20-100℃ to produce HI and H2SO4. The chemical reaction equations are as follows:

[0069] I2 + SO2 + 2H2O → 2HI + H2SO4;

[0070] HI and H2SO4 are separated, and H2SO4 is concentrated to obtain a high-concentration H2SO4 solution as a byproduct.

[0071] The HI obtained after separation is concentrated and purified before entering HI decomposition reaction unit 3. The HI decomposition reaction is carried out at 600-1200℃ without a catalyst. The chemical reaction equation is as follows:

[0072] 2HI→I2+H2;

[0073] All the generated I2 was injected into the Bunsen reaction system through the iodine injection port, and the generated H2 was stored in H2 storage tank 4.

[0074] In one specific embodiment of this example, the HI decomposition reaction device 3 further includes a slag discharge port through which the heat-transferred metallurgical high-temperature waste slag is discharged from the HI decomposition reaction device 3.

[0075] The horizontal level of the slag discharge port is lower than the horizontal level of the injection port.

[0076] Please see the appendix Figure 1 and attached Figure 2 In one specific embodiment of this example, the bottom of the HI decomposition reaction device 3 is provided with a slag collector 5. After being injected into the HI decomposition reaction device 3 through the injection port, it is heated and discharged through the slag discharge port and collected in the slag collector 5.

[0077] In one specific embodiment of this example, the metallurgical high-temperature waste slag includes blast furnace slag and steel slag;

[0078] In the direction of movement, the metallurgical high-temperature waste slag enters from the upper part (the inlet) of the HI decomposition reaction device 3 and exits from the lower part (the outlet).

[0079] In the direction of movement, HI enters from the lower part of the HI decomposition reaction device 3 (heat exchange tube plate 31) and flows upward to decompose.

[0080] In one specific embodiment of this example, a heat exchange tube plate 31 is provided inside the HI decomposition reaction device 3. The heat exchange tube plate 31 is inclined, and one end of the heat exchange tube plate 31 is connected to the inner wall of the HI decomposition reaction device 3. The horizontal height of the other end is less than the horizontal height of the end connected to the inner wall of the HI decomposition reaction device 3.

[0081] HI flows from the bottom to the top of the heat exchange tube sheet 31 for preheating and decomposition;

[0082] The metallurgical high-temperature waste slag injected into the HI decomposition reaction device 3 through the injection port is poured onto the heat exchange tube sheet 31.

[0083] In this invention, by setting the heat exchange tube sheet 31, while ensuring the normal downward flow of metallurgical high-temperature waste slag, it has a larger contact area and a longer contact time with it, thus achieving sufficient heat exchange.

[0084] Please see the appendix Figure 2 and attached Figure 3 In one specific embodiment of this example, the heat exchange tube sheet 31 is composed of a whole heat exchange core tube 311 arranged in a "S" shape.

[0085] The heat exchange core tube 311 is filled with thermally conductive particles, and the porosity of the heat exchange core tube 311 is 0.5.

[0086] HI flows back and forth inside the heat exchange core tube 311, fully exchanging heat with the heat-conducting particles and high-temperature metallurgical waste slag.

[0087] In this invention, the heat-conducting particles inside the heat exchange tube bundle are inert materials with high thermal conductivity. After filling, the porosity inside the tube is 0.5, which can increase the heat transfer rate from the wall to the inside of the fluid domain, and also enable the mixed gas to form vortices and disturb each other during the flow process, thereby enhancing the heat transfer effect between the fluids, further improving the heating rate, and making the HI temperature distribution more uniform.

[0088] In one specific embodiment of this example, the thermally conductive particles are SiC particles.

[0089] In one specific embodiment of this example, the heat exchange tube sheet 31 is composed of a single heat exchange core tube 311 arranged in a tight "S" shape.

[0090] Correspondingly, the heat exchange core tubes 311 arranged in a "S" shape include straight pipe sections and "U"-shaped sections, with the two ends of the "U"-shaped sections respectively connected to straight pipe sections arranged in parallel with each other;

[0091] The axial direction of the straight pipe section is parallel to the inclination direction of the heat exchange tube sheet 31, or...

[0092] The axial direction of the straight pipe section is perpendicular to the inclination direction of the heat exchange tube sheet 31.

[0093] Please see the appendix Figure 2 and attached Figure 3 In one specific embodiment of this example, multiple heat exchange tube sheets 31 are provided, and the multiple heat exchange tube sheets 31 are arranged sequentially and at intervals facing each other.

[0094] The horizontal height of the lower end of the upper heat exchanger tube sheet 31 is greater than the horizontal height of the upper end of the lower heat exchanger tube sheet 31.

[0095] Metallurgical high-temperature waste slag injected into the HI decomposition reaction device 3 through the injection port moves sequentially from top to bottom on multiple heat exchange tube plates 31.

[0096] In this invention, after the metallurgical high-temperature waste slag is discharged from the slag ditch, it falls into the first heat exchange tube plate 31 of the HI decomposition reaction device 3 through the injection port at the top of the HI decomposition reaction device 3. Under the action of gravity, it slides down to the end of the heat exchange tube plate 31 (the end with a lower horizontal height) and falls into the second heat exchange tube plate 31, and so on until the last heat exchange tube plate 31, after which it falls into the slag collector set at the bottom of the HI decomposition reaction device 3 through the slag discharge port.

[0097] The high-temperature metallurgical slag comes into direct contact with the heat exchange tube sheet 31 (contact heat transfer), and the heat is conducted to the heat exchange core tube 311 and the internal heat-conducting particles and HI. On the other hand, the heat dissipated continues to heat the upper heat exchange tube sheet 31 (thermal radiation heat transfer). After repeated heat exchange (through multiple heat exchange tube sheets 31 arranged from top to bottom), the high-temperature metallurgical slag is cooled to form metallurgical cooling slag, which enters the slag collector.

[0098] In one specific embodiment of this example, the outer periphery of the HI decomposition reaction device 3 is covered with thermal insulation material;

[0099] The design of using thermal insulation material to cover the outer perimeter helps to reduce heat loss, thereby further increasing the heating rate and ensuring that the decomposition reaction proceeds at the appropriate temperature.

[0100] In one specific embodiment of this example, the iodine-sulfur open-circuit hydrogen production process driven by the sensible heat of metallurgical high-temperature waste slag further includes: a thermocouple and a control component (not shown in the figure). The thermocouple is used to detect the temperature inside the HI decomposition reaction device 3, and the control component is used to receive the temperature detected by the thermocouple and adjust the inlet flow rate of the HI decomposition reaction device 3 according to the temperature to control the endothermic efficiency of the chemical reaction and ensure that the minimum temperature inside the HI decomposition reaction device 3 is above 600°C.

[0101] The thermocouple is disposed on the upper surface of the heat exchange tube sheet 31;

[0102] At least one thermocouple is provided for each heat exchange tube sheet 31 (multiple thermocouples may be provided);

[0103] Each heat exchange tube sheet 31 is provided with a thermocouple.

[0104] In one specific embodiment of this example, the angle between the heat exchange tube sheet 31 and the horizontal plane is 10°-75°.

[0105] It should be noted that in the scheme where multiple heat exchange tube sheets 31 are provided, the angles between the multiple heat exchange tube sheets 31 and the horizontal plane are the same, or...

[0106] Some of the heat exchanger tube sheets 31 have different angles with the horizontal plane, while other portions of the heat exchanger tube sheets 31 have the same angle with the horizontal plane, or...

[0107] The angle between any one of the multiple heat exchange tube sheets 31 and the horizontal plane is different.

[0108] In this invention, by setting the above-mentioned tilt angle, the metallurgical high-temperature waste slag is allowed to contact the heat exchange tube plate 31 as much as possible, ensuring that the metallurgical high-temperature waste slag flows down naturally while extending the contact area and contact time between the metallurgical high-temperature waste slag and the heat exchange tube plate 31.

[0109] In one specific embodiment of this invention, the high-temperature metallurgical waste slag is injected through the injection hole;

[0110] The injection angle of the metallurgical high-temperature waste slag is generally 90°, that is, it falls vertically.

[0111] Metallurgical high-temperature waste slag has a relatively low density and is in a molten state (liquid mobile phase) at high temperatures, so the impact force on the heat exchange tube sheet 31 when it falls vertically is relatively small.

[0112] Please see the appendix Figure 2 and attached Figure 3In one specific embodiment of this example, four heat exchange tube plates 31 are provided, and the four heat exchange tube plates 31 are respectively the first heat exchange tube plate, the second heat exchange tube plate, the third heat exchange tube plate and the fourth heat exchange tube plate from top to bottom in terms of horizontal height.

[0113] The first heat exchanger tube sheet is connected to the third heat exchanger tube sheet, and the second heat exchanger tube is connected to the fourth heat exchanger tube, or...

[0114] The first heat exchanger tube sheet is connected to the fourth heat exchanger tube sheet, and the second heat exchanger tube is connected to the third heat exchanger tube.

[0115] In this invention, in the scheme of connecting the heat exchange tube plate 31 set at the lower part (bottom side) and the heat exchange tube plate 31 set at the upper part (top side), the two heat exchange tube plates 31 cooperate, the lower heat exchange tube plate 31 has a lower temperature and mainly undertakes the preheating function, while the upper heat exchange tube plate 31 has a higher temperature and undertakes the high-temperature decomposition function.

[0116] The advantages of the solution provided in this application are:

[0117] 1) The process is simple and reliable, with low investment costs and good economic efficiency. It simplifies the process by eliminating the sulfuric acid decomposition unit in the traditional iodine-sulfur cycle hydrogen production process, greatly simplifying the process flow. Compared with existing open-loop, complex SO2 production processes, using SO2 generated from steel plant waste gas desulfurization as raw material significantly reduces the amount of equipment required. Furthermore, it converts SO2 in the waste gas into sulfuric acid, achieving waste reuse and resulting in better economic benefits.

[0118] 2) Improved system thermal efficiency and significantly reduced operating energy consumption. By adopting a strategy of direct heat exchange between high-temperature metallurgical waste slag and HI, the energy conversion process is avoided. The waste heat recovery rate of blast furnace slag is increased from 10% in the traditional water quenching method to more than 65%. Iodine-sulfur hydrogen production can achieve continuous and stable operation entirely by relying on the waste heat of blast furnace slag. Only water and SO2 by-products of waste gas desulfurization need to be input to produce H2 and sulfuric acid.

[0119] 3) Significantly reduced cost of iodine-sulfur hydrogen production. The simplified process system and efficient utilization of waste heat lead to a significant reduction in investment and operating costs for iodine-sulfur chemical hydrogen production. In addition, the efficient heat transfer can ensure that the temperature of the HI decomposition reactor is above 500℃, enabling catalyst-free high-temperature thermal decomposition of HI. This reduces catalyst costs and effectively avoids system problems caused by catalyst deactivation. The cost of iodine-sulfur hydrogen production can be reduced to below 3 yuan / kg H2.

[0120] 4) Improved HI decomposition efficiency and increased hydrogen production rate. The HI decomposition temperature is increased from 300-500℃ in the traditional iodine-sulfur process to 600-1200℃. The high temperature promotes the reaction rate, shortens the reaction time, and increases the decomposition rate. At 1200℃, the equilibrium decomposition rate can reach 63.3%, which is significantly higher than the 1% decomposition rate at 500℃ without a catalyst and 23% under the condition with a catalyst. The H2 yield is 2.5 times higher than that under the traditional catalytic condition.

[0121] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. The implementation schemes in the above embodiments can also be further combined or replaced. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A hydrogen production process by metallurgical high temperature waste slag sensible heat driven iodine-sulfur open cycle, characterized in that, include: SO2 storage tank, wherein the SO2 storage tank stores SO2 gas; The Bunsen system has its inlet connected to the outlet of the SO2 storage tank, and uses SO2 gas as one of the reaction raw materials. The HI decomposition reactor is connected to the Bunsen system and uses HI generated by the reaction in the Bunsen system as a raw material for the decomposition reaction. The I2 generated by the decomposition in the HI decomposition reactor is reintroduced into the Bunsen system as a reaction raw material for the Bunsen system. H2 storage tank, which is connected to the hydrogen outlet of the HI decomposition system, is used to store the H2 generated by the HI decomposition reaction device; The HI decomposition reaction device is equipped with an injection port through which metallurgical high-temperature waste slag is injected. The HI decomposition reactor performs the HI decomposition reaction by absorbing heat from high-temperature metallurgical waste slag.

2. The sensible heat-driven iodine-sulfur open-circuit hydrogen production process based on metallurgical high-temperature waste slag according to claim 1, characterized in that, The SO2 stored in the SO2 storage tank originates from high-concentration SO2 generated during flue gas desulfurization at the steel plant.

3. The sensible heat-driven iodine-sulfur open-circuit hydrogen production process based on metallurgical high-temperature waste slag according to claim 1, characterized in that, The Bunsen system also includes: Water is injected through the water inlet, with water being one of the reaction raw materials; Iodine injection port: I2 generated by the reaction of the HI decomposition reaction device is injected into the Bunsen through the iodine injection port. The generated H2SO4 is discharged from the Bunsen system through the sulfur discharge port.

4. The sensible heat-driven iodine-sulfur open-circuit hydrogen production process based on metallurgical high-temperature waste slag according to claim 1, characterized in that, The HI decomposition reaction device further includes: a slag discharge port, through which the heat-transferred high-temperature metallurgical waste slag is discharged from the HI decomposition reaction device. The horizontal level of the slag discharge port is lower than the horizontal level of the injection port.

5. The sensible heat-driven iodine-sulfur open-circuit hydrogen production process based on metallurgical high-temperature waste slag according to claim 4, characterized in that, The metallurgical high-temperature waste slag includes blast furnace slag and steel slag.

6. The sensible heat-driven iodine-sulfur open-circuit hydrogen production process based on metallurgical high-temperature waste slag according to claim 4, characterized in that, The HI decomposition reactor is equipped with a heat exchange tube sheet, which is inclined. One end of the heat exchange tube sheet is connected to the inner wall of the HI decomposition reactor, and the horizontal height of the other end is less than the horizontal height of the end connected to the inner wall of the HI decomposition reactor. HI flows from the bottom to the top of the heat exchange tube sheet for preheating and decomposition; The high-temperature metallurgical waste slag injected into the HI decomposition reactor through the injection port is poured onto the heat exchange tube sheet.

7. The sensible heat-driven iodine-sulfur open-circuit hydrogen production process based on metallurgical high-temperature waste slag according to claim 6, characterized in that, The heat exchange tube sheet is composed of a single heat exchange core tube arranged in a tight "S" shape; The heat exchange core tube is filled with thermally conductive particles, and the porosity of the heat exchange core tube is 0.

5.

8. The sensible heat-driven iodine-sulfur open-circuit hydrogen production process based on metallurgical high-temperature waste slag according to claim 7, characterized in that, Multiple heat exchanger tube sheets are provided, and the multiple heat exchanger tube sheets are arranged sequentially and at intervals facing each other. The horizontal height of the lower end of the upper heat exchanger tube sheet in two adjacent heat exchanger tube sheets is greater than the horizontal height of the upper end of the lower heat exchanger tube sheet in two adjacent heat exchanger tube sheets. Metallurgical high-temperature waste slag injected into the HI decomposition reactor through the injection port moves sequentially from top to bottom on multiple heat exchange tube sheets.

9. The sensible heat-driven iodine-sulfur open-circuit hydrogen production process based on metallurgical high-temperature waste slag according to claim 8, characterized in that, The angle between the heat exchange tube sheet and the horizontal plane is 10°-75°.

10. A metallurgical high-temperature waste slag sensible heat-driven iodine-sulfur open-circuit hydrogen production process according to claim 8 or 9, characterized in that, There are four heat exchange tube sheets, which are arranged from top to bottom horizontally as the first heat exchange tube sheet, the second heat exchange tube sheet, the third heat exchange tube sheet and the fourth heat exchange tube sheet; The first heat exchanger tube sheet is connected to the third heat exchanger tube sheet, and the second heat exchanger tube is connected to the fourth heat exchanger tube, or... The first heat exchanger tube sheet is connected to the fourth heat exchanger tube sheet, and the second heat exchanger tube is connected to the third heat exchanger tube.

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