Oxygen radical elimination catalytic converter, Alkaline water electrolysis hydrogen production system and control method

Abstract

The application discloses an oxygen free radical elimination catalytic converter, an alkaline water electrolysis hydrogen production system and a control method, which realizes the capture of oxygen free radicals generated on the anode side, and through the setting of a feed inlet, a partition plate structure and the like, the volume flow of the gas-liquid mixture is dynamically regulated according to the electrolytic tank load control flow area, and the risk of bubble blockage and pipeline pressure drop is reduced. According to the composition of the oxygen free radicals, the catalytic unit is divided into three layers, and the various components of the oxygen free radicals in the fluid are processed in stages, so that the capture efficiency of the catalytic converter for the oxygen free radicals is improved. The catalytic conversion module is composed of two or more oxygen free radical catalytic converters, which are alternately operated, a make-up alkali tank is arranged at the outlet of the catalytic conversion module as a backwashing module, the oxygen free radical catalytic converter after operation is flushed and operated and maintained, and the capture efficiency of the catalytic converter for the oxygen free radicals is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen production by alkaline electrolysis of water. More specifically, the present application relates to an oxygen radical elimination catalytic converter, an alkaline water electrolysis hydrogen production system and a control method. BACKGROUND

[0002] Hydrogen energy is considered an important part of the future energy system as a clean and efficient energy carrier. According to the production process and production by-products, hydrogen production technologies are divided into blue hydrogen, gray hydrogen and green hydrogen modes. Among the many hydrogen production technologies, water electrolysis technology is widely concerned for its environmental protection and sustainability. Among them, the alkaline water electrolysis hydrogen production technology has the lowest equipment cost, a longer development history, the most mature technology, rich industrialization economy, and is suitable for large-scale hydrogen production in the industrialization process. The stability of the alkaline water electrolysis hydrogen production process also supports the coupling of intermittent renewable energy sources such as solar and wind energy, and alleviates the pressure on the power grid.

[0003] Due to the characteristics of the electrolysis reaction and the complex electrolyte environmental factors, the electrolysis efficiency of the alkaline water electrolysis system is less than 100% during operation, and oxygen radicals such as hydroxyl radicals · OH , superoxide anion radicals are inevitably generated on the anode side. Oxygen radicals themselves have strong oxidizing properties, and they enter each BoP (Balance of Plant) component of the electrolysis system with the circulating alkali solution, adhere to the inner wall and oxidize it, which is the fundamental reason for the corrosion of the inner wall of the BoP component of the alkaline water electrolysis hydrogen production system and the reduction of its service life. After a period of operation, the surface of the BoP component will fall off or ions will be precipitated, causing impurities in the circulating alkali solution and the collected gas. At the same time, the oxygen radicals generated on the anode side will gradually deposit with the circulation of the alkali solution, causing the oxygen evolution side reaction, resulting in a decrease in the effective current for the electrolysis reaction. Some oxygen radicals adhere to the surface of the electrode along with the micro-bubbles carried by the circulating alkali solution, corrode the surface catalyst layer, increase the overpotential of the electrode reaction, and reduce the electrolysis efficiency.

[0004] At the same time, the purification system of most existing alkaline water electrolysis hydrogen production systems only targets the separated gas at the downstream end, cools and removes the impurities in the alkali solution, and does not consider the challenge of harmful substances accompanying the circulation of the alkali solution in actual operation. There is a lack of analysis of the service life of the alkaline water electrolysis hydrogen production system equipment from the source, i.e. the electrolysis reaction. In particular, the operation and maintenance cycle of the alkaline water electrolysis system is relatively long, which makes it difficult to observe the impact of oxygen radical corrosion in a closed environment, which is undoubtedly a hidden danger for the operation of the alkaline water electrolysis hydrogen production system.

[0005] Finally, the invention of the existing alkaline electrolytic water system components lacks dynamic analysis for working condition changes. In the actual operation process of the electrolytic cell, according to different workloads, the gas production rate at the outlet and the alkali circulation amount will change. The fixed structure of the alkali filter will form a deposition layer that affects the flow state of the alkali, and often the operating power and the pipeline pressure drop do not match. The change in the flow state of the alkali increases the concentration overpotential on the surface of the electrode, ultimately affecting the working performance of the alkaline water hydrogen production electrolytic cell. With the development of industrialization, the scale of the alkaline water electrolysis hydrogen production system is gradually expanding, and the range of working condition changes is also increasing. Therefore, it is very important to develop a catalytic converter that is suitable for high-efficiency removal of oxygen free radicals in a wide power range. SUMMARY

[0006] An object of the present application is to provide an oxygen free radical elimination catalytic converter, an alkaline water electrolysis hydrogen production system and a control method, which realizes the capture of oxygen free radicals generated on the anode side, and by setting a rotating valve at the inlet and a baffle structure near the outlet, the flow area is adjusted according to the load of the electrolytic cell, thereby dynamically adjusting the volume flow of the gas-liquid mixture, reducing the risk of bubble blockage and pipeline pressure drop. A baffle plate is installed inside the sleeve to achieve preliminary separation of the gas-liquid mixture using density difference, and the alkali and gas are treated separately. The catalytic unit is divided into three layers according to the composition of oxygen free radicals, and the various components of oxygen free radicals in the fluid are treated in stages, improving the capture efficiency of the catalytic converter for oxygen free radicals. The catalytic conversion module is composed of 2 or more oxygen free radical catalytic converters, which operate alternately, and a alkali supplement tank is set at the outlet of the catalytic conversion module as a backwashing module to flush and maintain the oxygen free radical catalytic converter after operation, improving the capture efficiency of the catalytic converter for oxygen free radicals.

[0007] In order to solve the above technical problems, the application provides an oxygen radical elimination catalytic converter, which comprises a horizontally assembled shell, a sleeve coaxially arranged in the shell and a plurality of catalytic units, one end of the shell is sealed by a valve core, the other end is sealed and provided with a shell outlet; the sleeve is a hollow sealed cavity structure, one end of the sleeve close to the valve core is tightly and sealingly arranged with the valve core, a plurality of feeding ports are arranged on the one end of the sleeve close to the valve core, a plurality of communication holes are arranged on the valve core and communicate with the feeding ports; a plurality of baffles are arranged on the inner wall of the sleeve in sequence, staggered and spaced; an exhaust port and a liquid discharge port are arranged on the one end of the sleeve close to the shell outlet in sequence; a plurality of catalytic units are arranged in sequence, staggered and parallel between the sleeve and the shell outlet for layered treatment of gas and liquid, the catalytic unit comprises two catalytic coating layers arranged symmetrically in sequence, the pore diameters of the plurality of catalytic units decrease in sequence along the gas and liquid flow direction, and the pore diameters of the two catalytic coating layers of the same catalytic unit decrease from bottom to top; the communication holes are communicated with the anode side outlet of the electrolytic cell of the electrolytic hydrogen production system, so as to pass the mixture of alkali liquor and gas into the sleeve through the feeding ports, the exhaust port is used for passing the gas and small particle size alkali liquor into the upper catalytic coating layer of the catalytic unit, and the liquid discharge port is used for passing the alkali liquor into the lower catalytic coating layer.

[0008] Preferably, the sleeve is rotationally arranged, so as to adjust the through area size between the communication holes and the feeding ports.

[0009] Preferably, the shell inner wall is provided with a baffle at the positions corresponding to the exhaust port and the liquid discharge port, the size of the baffle is matched with the exhaust port and the liquid discharge port, and the baffle is used for adjusting the flow area of the exhaust port and the liquid discharge port by the rotation of the sleeve, so as to adapt to the flow of the gas-liquid mixture generated under different loads of the electrolytic cell.

[0010] Preferably, the plurality of feeding ports are symmetrically arranged along the vertical axis of the sleeve, and an included angle is arranged between the central axis of the baffle and the vertical axis of the sleeve, which is 30° to 45°.

[0011] Preferably, a plurality of baffles are arranged on the liquid discharge port side and the exhaust port side of the sleeve respectively and extend towards the center of the sleeve, the baffles are semicircular and the bottom radius is equal to the radius of the sleeve, and a plurality of filter holes are arranged on the baffles for filtering the alkali liquor.

[0012] Preferably, a space is arranged between the two catalytic coating layers of the catalytic unit, and a space is also arranged between the adjacent catalytic units, so as to balance the pressure drop of the gas and liquid in the treatment process.

[0013] The application also provides an alkaline water electrolysis hydrogen production system provided with an oxygen radical elimination catalytic converter, comprising an electrolytic cell, a catalytic conversion module, an alkali supplement tank and a gas-liquid separator, the catalytic conversion module feed inlet is connected to the anode side outlet of the electrolytic cell, the catalytic conversion module outlet is connected to the anode side gas-liquid separator feed inlet and the alkali supplement tank, the catalytic conversion module comprises at least two oxygen radical elimination catalytic converters with the same alkali liquid flow range, which are arranged in parallel to form at least two catalytic conversion branches, electromagnetic valves are arranged on the electrolytic cell anode side outlet pipeline, the anode side gas-liquid separator feed inlet pipeline, the alkali supplement tank pipeline and the two catalytic conversion branch outlet pipelines, a rotary valve is arranged on the two catalytic conversion branch inlet pipelines, and flow detectors are arranged on the at least two catalytic conversion branches to detect the flow before and after the corresponding oxygen radical elimination catalytic converter.

[0014] Preferably, H2O2 concentration detectors are arranged at the outlets of the two catalytic conversion branches, the alkali supplement tank is connected to an alkali liquid circulation controller, and the electrolytic cell anode side outlet is further connected to a sewage system, and an electromagnetic valve is arranged on the pipeline of the sewage system.

[0015] The application also provides a control method for an alkaline water electrolysis hydrogen production system, comprising the following steps:

[0016] Step one: the electrolytic cell is operated, the generated gas and the circulating alkali liquid enter the catalytic conversion module from the anode side outlet, the rotary valves of the two catalytic conversion branches are controlled to distribute the gas-liquid mixture flow, and then the gas-liquid mixture flow enters the corresponding oxygen radical elimination catalytic converter;

[0017] Step two: one or more oxygen radical elimination catalytic converters are operated, the outlet alkali liquid flow is detected by the corresponding flow detector, if the flow is lower than the limit demand set under the current working condition, the rotary valve at the inlet of the branch is controlled to increase the gas-liquid mixture flow, if the flow is higher than the limit demand set under the current working condition, the rotary valve at the inlet of the branch is controlled to reduce the gas-liquid mixture flow, and the process is repeated until the set demand is reached.

[0018] Preferably, the method further comprises:

[0019] When the oxygen radical elimination catalytic converter is operated, the oxygen radical content at the outlet is monitored by the H2O2 concentration detector arranged on each catalytic conversion branch, if the oxygen radical content exceeds the set limit value, the operation and maintenance mode is entered, that is, the catalytic conversion branch is closed and the other catalytic conversion branch is opened, the electromagnetic valves on the branch of the corresponding alkali supplement tank and the sewage system of the catalytic conversion branch in the operation and maintenance mode are opened, the oxygen radical catalytic converter in the operation and maintenance mode is backwashed, and the operation is restored when the oxygen radical content is less than the demand value, if the oxygen radical content still exceeds the limit value after a period of backwashing, manual disassembly and operation and maintenance are performed.

[0020] The present application at least includes the following advantages:

[0021] (1) The oxygen radical elimination catalytic converter uses the linkage of the valve core and the sleeve to change the inlet mass flow of the gas-liquid mixture in real time according to the output power of the electrolytic cell, and changes the contact area with the baffle by rotating the connected sleeve to adjust the flow rate of the gas and the lye, thereby ensuring the stable flow of the gas and the liquid in the catalytic unit under different working conditions, improving the catalytic conversion efficiency, effectively breaking through the technical barriers of the narrow applicable working condition range and poor flexibility caused by the fixed structure of the existing alkaline water electrolysis hydrogen production system equipment, and comprehensively improving the operation cycle of the electrolytic hydrogen production system components in a wide load range (the fluctuation adaptation range is about 35%-110%).

[0022] (2) The present application adds baffles at the top and bottom of the sleeve, which can effectively separate the gas-liquid mixture at the outlet of the electrolytic cell, maintain the relative stability of the subsequent flow of the gas and the liquid under working condition changes, further horizontally install the oxygen radical catalytic converter, and make the gas and the lye after catalytic conversion enter the subsequent gas-liquid separator of the electrolytic hydrogen production system in a stable flow state, thereby reducing the working load and the vessel pressure drop, and further reducing the manufacturing cost.

[0023] (3) The present application divides the catalytic unit of the shell into three columns of catalytic units, which can capture and remove various oxygen radical components in stages. According to the flow resistance difference of the gas and the liquid in the pipeline, the catalytic unit is divided into two layers, the upper layer catalytic coating has a smaller pore size than the lower layer catalytic coating for processing the liquid. The pore size of each column of catalytic units gradually decreases along the gas-liquid flow direction, which is used for separation, coalescence and separation of the bubbles carried or generated, and prevents the blockage of bubbles in the catalytic oxidation process.

[0024] (4) The present application sets the catalytic conversion module at the anode side of the electrolytic cell of the alkaline water electrolysis hydrogen production system, performs layered and staged purification on the gas-liquid mixture, maintains the stability of the pipeline pressure drop, reduces the working load of the system gas-liquid separator, and fundamentally avoids the corrosion of the lye to the system components outside the electrolytic cell, thereby reducing the operation and maintenance cost. The two catalytic converters of the catalytic conversion module operate alternately to capture the oxygen radicals carried in the gas and the liquid in stages. Meanwhile, a lye supplement tank is arranged at the outlet of the catalytic conversion module as a backwashing module, which realizes stable operation under load changes in combination with the control of the branch and total electromagnetic valves, improves the applicable cycle of the catalytic converter, realizes the operation detection of the catalytic efficiency of the oxygen radical catalytic converter through the concentration monitor, maintains the stable operation of the electrolytic system under different working conditions, improves the economy of the system, and is convenient for operation and maintenance.

[0025] Other advantages, objects, and features of the present application will be apparent from the following description, and will be understood by those skilled in the art through a study of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 Figure 1 is a perspective view of the oxygen radical elimination catalytic converter of the present application;

[0027] Figure 2 Figure 2 is a sectional view of the oxygen radical elimination catalytic converter of the present application;

[0028] Figure 3 is a schematic diagram of the working principle of the oxygen radical elimination catalytic converter of the present application;

[0029] Figure 3(a) is the principle of the oxygen radical elimination catalytic converter of the present application, Figure 3(b) is the gas flow trace diagram when the cross-sectional area of the feed inlet of the oxygen radical elimination catalytic converter of the present application is maximum, and Figure 3(c) is the gas flow trace diagram when the feed inlet of the oxygen radical elimination catalytic converter of the present application is closed;

[0030] Figure 4 Figure 4 is a perspective view of the sleeve of the present application;

[0031] Figures 5~7 Figure 5 is a schematic diagram of the pore size of the first to third catalytic units along the gas-liquid flow direction of the present application;

[0032] Figure 8 Figure 6 is a schematic diagram of the phase angle distribution of the present application.

[0033] Figure 9 Figure 7 is a structural schematic diagram of the alkaline water electrolysis hydrogen production system of the present application;

[0034] Figure 10 Figure 8 is a structural schematic diagram of the catalytic conversion module of the alkaline water electrolysis hydrogen production system of the present application;

[0035] Figure 11 Figure 9 is a control block diagram of the catalytic conversion module of the alkaline water electrolysis hydrogen production system of the present application.

[0036] BRIEF DESCRIPTION OF DRAWINGS

[0037] 1 - servo motor; 2 - valve core; 3 - communication hole; 4 - sealing assembly; 5 - shell; 6 - sleeve; 7 - first gas catalytic conversion layer; 8 - second gas catalytic conversion layer; 9 - third gas catalytic conversion layer; 10 - first liquid catalytic conversion layer; 11 - second liquid catalytic conversion layer; 12 - third liquid catalytic conversion layer; 13 - shell outlet; 14 - feed inlet; 15 - baffle; 16 - exhaust port; 17 - liquid discharge port; 18 - partition plate; 19 - electrolytic cell; 20 - catalytic conversion module; 21 - gas-liquid separator; 22 - alkali supplement tank; 23 - alkali liquor circulation controller; 24 - first electromagnetic valve; 25 - second electromagnetic valve; 26 - third electromagnetic valve; 27 - fourth electromagnetic valve; 28 - fifth electromagnetic valve; 29 - sixth electromagnetic valve; 30 - first rotary valve; 31 - second rotary valve; 32 - first flow detector; 33 - second flow detector; 34 - first oxygen radical elimination catalytic converter; 35 - second oxygen radical elimination catalytic converter; 36 - first H2O2 concentration detector; 37 - second H2O2 concentration detector. DETAILED DESCRIPTION

[0038] In order to better understand the purpose, structure and function of the present application, the following further detailed description of the present application is made in conjunction with the accompanying drawings, so that those skilled in the art can implement the present application according to the description.

[0039] It should be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial channels unless otherwise specified; in the description of the present application, the terms "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the present application.

[0040] As Figure 1 and Figure 2As shown, the application discloses a catalytic converter for eliminating oxygen radicals of an alkaline water electrolysis hydrogen production system, which comprises a shell 5, a sleeve 6, a valve core and a catalytic unit, the shell is cylindrical, one side is open and closed as a whole by the valve core 2, the other side is connected as a whole by a side plate, the side plate is provided with a shell outlet 13, so that the whole shell is a hollow sealed cavity structure, the sleeve 6 is coaxial with the center axis of the shell, which is also a hollow sealed cavity structure, the sleeve 6 is provided with a gas-liquid separation layer, a feed inlet 14, an exhaust outlet 16 and a liquid outlet 17, the gas-liquid separation layer is composed of multiple baffles 15 with filter holes, which is used for separating the gas-liquid mixture to facilitate the catalytic unit to capture and eliminate oxygen radicals of gas and liquid respectively, the feed inlet 14 is arranged on one side of the sleeve relative to the valve core and is used for feeding the mixture composed of alkali solution and gas into the sleeve 6, the exhaust outlet 16 is used for feeding the gas and alkali mist and other small particle size alkali solution into the upper catalytic coating of the catalytic unit, and the liquid outlet 17 is used for feeding the alkali solution into the lower catalytic coating; the inner wall of the shell is provided with a partition plate 18 near the exhaust outlet and the liquid outlet, which is used for cooperating with the regulation and control of the flow area of the exhaust outlet 16 and the liquid outlet 17, and is suitable for the flow of the gas-liquid mixture generated under different loads of the electrolytic cell, in the rotation process of the sleeve, the exhaust outlet 16 and the liquid outlet 17 contact with the partition plate 18, the flow area of the gas and the alkali solution changes, and the flow of the gas-liquid mixture generated under different loads of the electrolytic cell changes.

[0041] As Figure 4 shown, the baffles 15 are arranged on the liquid outlet 17 side and the exhaust outlet 16 side of the sleeve 6 and extend towards the center of the sleeve 6, the baffles are matched with the width of the sleeve 6, that is, the baffles are semicircular and the bottom radius is equal to the radius of the sleeve, that is, if there is no filter hole, the baffles can completely block the movement of the liquid at the bottom of the sleeve. The multiple baffles 15 are arranged in an upper and lower interval and are oppositely arranged, the baffles 15 are provided with a plurality of filter holes for filtering the alkali solution. In order to achieve the best effect of gas-liquid separation at this stage, the catalytic converter is horizontally assembled, the gas-liquid mixture can be effectively layered after flowing through the catalytic converter of the application, thereby reducing the working load of the subsequent gas-liquid separator in the electrolytic hydrogen production system, reducing the volume of the gas-liquid separator, making the design compact, and reducing the manufacturing cost.

[0042] The valve core 2 is installed at one end of the feed inlet 14 of the rotatable sleeve 6, and a sealing assembly 4 such as a gasket is arranged between the valve core 2 and the sleeve 6 to prevent leakage of the alkali solution and the gas; the valve core 2 is rotatably connected with the servo motor 1, and the servo motor 1 is used to drive the sleeve 6 to rotate; the sleeve 6 is provided with at least two phase angle distributed feed inlets 14, and the valve core 2 is a plate-shaped structure provided with a plurality of communication holes 3 and connected with the anode side outlet of the electrolytic cell of the electrolytic hydrogen production system; by rotating the sleeve 6, the sleeve feed inlets 14 with different phase angle distributions are all or partially communicated with the corresponding plurality of communication holes 3 on the valve core 2, which is used to preliminarily control the flow and speed of the gas-liquid mixture entering the sleeve. The vertical axis of the sleeve, i.e. Figure 8 the vertical axis of the sleeve, is the vertical axis of the sleeve cross section passing through the center point. The liquid outlet and the gas outlet are located at the upper and lower ends of the vertical axis.

[0043] A baffle plate 18 is arranged on the inner wall of the shell 5 at the positions corresponding to the gas outlet and the liquid outlet, and the contact area of the baffle plate 18 with the liquid outlet 17 and the gas outlet 16 is changed by the sleeve rotation control, thereby changing the flow of the liquid and the gas entering the catalytic coating, as shown in Figure 8 An angle is arranged between the central axis of the baffle plate 18 and the vertical axis of the sleeve, forming a phase angle difference, preferably 30° to 45°, to adapt to the control of the flow rate of the separated gas and liquid under the change of the gas-liquid mixture flow, and to strengthen the subsequent catalytic layer in capturing and eliminating the impurities in the alkali solution and the gas by oxygen free radicals. If no angle is arranged between the central axis of the baffle plate 18 and the vertical axis of the sleeve, the baffle plate is horizontally placed, the baffle plate and the gas outlet and the liquid outlet of the sleeve coincide, the exhaust and the liquid discharge rate is reduced, and in severe cases, it will cause blockage, so a certain phase difference is arranged between the baffle plate and the sleeve. The setting range of the phase angle difference between the baffle plate and the sleeve is based on: calculating the blocking area of the baffle plate to the gas (liquid) outlet under the condition of the maximum feed inlet area, thereby adjusting the phase angle between the baffle plate and the feed inlet, and finding the relatively optimal phase angle difference through multiple iteration calculations.

[0044] The plurality of feed inlets are symmetrically arranged along the vertical axis of the sleeve, which is used in larger scale AWE systems to process higher flow of the gas-liquid mixture from the anode side outlet of the electrolytic cell. The feed inlets and the communication holes of the present application are described by taking two as an example. If the number of feed inlets is increased, the area of the gas-liquid mixture to be processed is increased, and therefore the contact area of the gas outlet and the liquid outlet with the baffle plate is increased, and the size and area of the baffle plate and the gas outlet and the liquid outlet are also adjusted accordingly.

[0045] The three catalytic units in the shell 5 are arranged in parallel and have two catalytic coatings on the upper and lower surfaces, which are symmetrically arranged along the horizontal axis of the sleeve cross section to treat the gas and the alkali mist impurities and the oxygen radical components contained in the alkali solution after the preliminary gas-liquid separation of the sleeve, respectively. The height of the catalytic coating is 3-5 mm, and the spacing between the catalytic units is 5-7 mm to balance the pressure drop of the gas-liquid change in the treatment process.

[0046] The catalytic units in the shell 5 are named as the first catalytic unit, the second catalytic unit and the third catalytic unit along the gas-liquid flow direction to gradually treat the oxygen radical components enriched by the anode side reaction. The pore sizes of the three alkali solution catalytic units gradually decrease along the gas-liquid flow direction, preferably 100 μm, 50 μm and 10 μm, and the pore sizes of the three gas catalytic units gradually decrease along the gas-liquid flow direction, preferably 80 μm, 30 μm and 5 μm. As shown in Figure 5 、 Figure 6 and Figure 7 The bubbles carried in the alkali solution are coalesced into large-sized bubbles after contacting the small-pore-size catalytic units, and then are separated and discharged from the liquid, effectively avoiding the problem of bubble blockage in the catalytic units. According to the working conditions of the electrolytic cell, the pore size of the bubbles in the gas-liquid mixture at the outlet of the electrolytic cell is 200-500 μm, and the bubbles are broken and reformed after passing through the baffle with a pore size, which is reduced by about 70% compared with the original size. Therefore, the diameter of the bubbles is reduced to 60 μm-150 μm when passing through the lower liquid catalytic coating.

[0047] The first catalytic unit includes the alkali solution catalytic coating (the first liquid catalytic conversion layer 10) loaded with Pt / C catalyst and the porous titanium gas diffusion catalytic coating (the first gas catalytic conversion layer 7) for preferentially decomposing H2O2 and preventing ·OH produced by the volatilization and decomposition of subsequent H2O2 with high-temperature alkali solution from corroding the metal pipeline and the sealing material.

[0048] The second catalytic unit includes the alkali solution catalytic coating (the second liquid catalytic conversion layer 11) loaded with Mn / C catalyst and Pt / C catalyst and the porous titanium gas diffusion catalytic coating (the second gas catalytic conversion layer 8) subjected to surface sulfonation treatment, and the surface sulfonation treatment process is to introduce groups on the surface of the gas diffusion catalytic coating carrier to enhance the electrostatic adsorption of The alkali solution catalytic coating 11 loaded with Pt / C catalyst and the porous titanium gas diffusion catalytic coating 8 are to decompose the H2O2 newly produced by the disproportionation reaction.

[0049] The third catalytic unit includes the alkali solution catalytic coating (the third liquid catalytic conversion layer 12) loaded with The alkali liquid catalytic coating (third liquid catalytic conversion layer 12) and the porous gas diffusion catalytic coating (third gas catalytic conversion layer 9) are used for removing ·OH, the pore size of the alkali liquid and the gas catalytic coating is the smallest, the gas bubbles in the alkali liquid are eliminated to the maximum extent, the ·OH is prevented from entering the downstream of the alkali water electrolysis hydrogen production system with the gas bubbles, and the gas bubbles are prevented from being blocked in the catalytic converter.

[0050] The connection between the shell of the oxygen free radical elimination catalytic converter and the catalytic unit is provided with a spring buckle, so that the connection is detachable.

[0051] The working process of the oxygen free radical elimination catalytic converter is as follows:

[0052] As shown in FIG. 3(a), it is a working principle diagram of the oxygen free radical elimination catalytic converter. When the electrolytic cell is running, the gas-liquid mixture composed of the gas generated at the electrode and the circulating alkali liquid introduced into the electrolytic cell is discharged from the electrolytic cell outlet. The separated gas, small particle size alkali liquid and alkali mist in the baffle of the sleeve are discharged through the gas outlet at the top of the sleeve, enter the top of the catalytic unit of the catalytic converter shell, flow through the upper layers of the first catalytic unit, the second catalytic unit and the third catalytic unit, and capture and eliminate the and The separated gas, small particle size alkali liquid and alkali mist in the baffle of the sleeve are discharged through the gas outlet at the top of the sleeve, enter the top of the catalytic unit of the catalytic converter shell, flow through the upper layers of the first catalytic unit, the second catalytic unit and the third catalytic unit, and capture and eliminate the The capture and elimination are carried out, and then the catalytic converter is flowed out through the shell outlet. The gravity potential energy generated by the agglomerates of the attached alkali mist and liquid droplets combined in the pore diameter is used to make them fall to the flowing alkali liquor, so that the gas-liquid stratification can be realized, and the content of the alkali liquor impurities carried by the gas at the shell outlet can be effectively controlled. As shown in FIG. 3(b) and FIG. 3(c), according to different application conditions, based on the phase angle deviation, the rotation of the sleeve will affect the effective cross-sectional area of the oxygen radical catalytic converter inlet, so as to control the volume flow rate of the gas-liquid mixture entering, and then adjust the gas-liquid separation efficiency of the sleeve under varying conditions; at the same time, during the adjustment process, the contact area of the exhaust port and the liquid discharge port of the sleeve with the partition plate of the shell changes synchronously, the flow rates of the gas and the liquid after preliminary separation change, and the gas and the liquid enter the catalytic conversion unit of the shell along the exhaust port and the liquid discharge port respectively, so that the catalytic conversion efficiency is improved by changing the gas-liquid flow time, and the pipeline pressure drop is stabilized. In the present application, the load change will affect the gas production rate in the electrolysis process, and the flow rate of the alkali liquor circulation is currently constant, so the total volume of the gas-liquid mixture will change. In the present application, the flow velocity is kept constant (such as 2 m / s), and the size of the inlet is controlled to control the flow area.

[0053] The application further discloses an alkali water electrolysis hydrogen production system provided with an oxygen radical elimination catalytic converter for eliminating oxygen radical corrosion. Figure 9 As shown in the figure, an oxygen radical corrosion elimination alkaline electrolytic water system comprises an electrolytic tank 19, an alkali supplement tank 22, an alkali liquor circulation controller 23, a gas-liquid separator 21, an alkali liquor filter, a catalytic conversion module 20 and an alkali liquor circulation module, the alkali liquor circulation module comprises an alkali liquor circulation pump and an alkali liquor circulation heat exchanger; the catalytic conversion module inlet is connected to the anode side outlet of the electrolytic tank 19 (receives the gas-liquid mixture from the electrolytic tank, and a fifth electromagnetic valve 28 is arranged on the pipeline) and a pollution discharge system (a sixth electromagnetic valve 29 is arranged on the pipeline thereof), the catalytic conversion module outlet is connected to the anode side gas-liquid separator 21 inlet (a fourth electromagnetic valve 27 is arranged on the pipeline) and the alkali supplement tank 9 (a third electromagnetic valve 26 is arranged on the pipeline) respectively; the anode side gas-liquid separator 21 liquid discharge port is connected to the electrolytic tank 19 anode side inlet through the alkali liquor circulation module and the alkali liquor filter to form a closed loop circulation system, and the gas-liquid separator 21 gas discharge port is connected to a gas purification and collection device; the alkali liquor circulation controller 23 is connected to the alkali supplement tank 22; a plurality of branch pipes corresponding to the oxygen radical elimination catalytic converters are arranged on the alkali supplement tank and the pollution discharge system respectively, and the third electromagnetic valve 26 and the sixth electromagnetic valve 29 are arranged on the branch pipes respectively.

[0054] The alkali supplement tank 22 is connected to the outlet of the catalytic conversion module and the inlet of the anode side gas-liquid separator 21 through a third electromagnetic valve, forming a backwashing module; the alkali liquid flow meters installed on each branch of the catalytic conversion module 20 and the alkali supplement tank 22 are connected to an alkali liquid circulation controller 23; the alkali liquid circulation module comprises an alkali liquid circulation pump and an alkali liquid circulation heat exchanger, and the liquid outlet of the anode side gas-liquid separator 21 is connected to the alkali liquid circulation pump and connected to the electrolytic tank 19 of the alkaline electrolytic water hydrogen production device through the alkali liquid circulation heat exchanger. In the operation mode, the alkali liquid circulation controller 23 needs to output alkali liquid from the alkali supplement tank for pollution discharge; in the working mode, the alkali liquid circulation controller 23 needs to adjust the alkali liquid entering and leaving the alkali supplement tank, and keep the alkali liquid flow of the alkali liquid circulation system stable.

[0055] As shown in Figure 10 The catalytic conversion module 20 comprises at least two oxygen radical elimination catalytic converters with the same alkali liquid flow range, and the oxygen radical elimination catalytic converters are connected in parallel, and at least one oxygen radical elimination catalytic converter works in the process. The application is described by taking two oxygen radical elimination catalytic converters as an example. The first catalytic conversion branch is provided with a first rotary valve 30, a first oxygen radical elimination catalytic converter 34, a first flow detector 32 for detecting the flow before and after the first oxygen radical elimination catalytic converter 34, and a first electromagnetic valve 24, and the second catalytic conversion branch is provided with a second rotary valve 31, a second oxygen radical elimination catalytic converter 35, a second flow detector 33 for detecting the flow before and after the second oxygen radical elimination catalytic converter, and a second electromagnetic valve 25. The first H2O2 concentration detector 36 and the second H2O2 concentration detector 37 are respectively arranged at the outlets of the two catalytic conversion branches. The first H2O2 concentration detector is added between the first electromagnetic valve and the first oxygen radical elimination catalytic converter, and the second H2O2 concentration detector is added between the second electromagnetic valve and the second oxygen radical elimination catalytic converter. The first flow detector and the second flow detector of the application adopt flow meters in actual use.

[0056] As shown in Figure 11 The application further discloses a control method of the oxygen radical elimination catalytic conversion module.

[0057] (1) The electrolytic tank is operated to generate oxygen gas and circulating alkali liquid which enter the catalytic conversion module from the anode side outlet, and the flow of the gas-liquid mixture is distributed through the rotary valves of the two branches, and then enters the corresponding oxygen radical elimination catalytic converter of the branch.

[0058] (2) The first or second or all oxygen radical elimination catalytic converters are operated, the alkali solution flow rate at the outlet of the oxygen radical elimination catalytic converter is monitored by the alkali solution flow rate detector, and according to the number of oxygen radical elimination catalytic converters in operation, when two oxygen radical elimination catalytic converters are operated, the flow rate of the two branches is theoretically about 1 / 2 under the condition that the alkali solution demand of the system is unchanged and the pressure is unchanged, and therefore, if the flow rate is less than half of the alkali solution demand of the electrolytic cell under the current operating condition, the inlet rotary valve of the branch is controlled to increase the flow rate of the gas-liquid mixture; when the operating condition of the alkali electrolytic cell fluctuates, the flow rate of the gas-liquid mixture is unstable, and the alkali solution flow rate detector detects that the content of a branch is too high, for example, the flow rate fluctuation is too large and exceeds the set value, for example, exceeds 10%, the inlet rotary valve of the branch is controlled to reduce the flow rate, and the electromagnetic valve corresponding to the alkali supplement tank on the outlet of the catalytic conversion module of the branch is opened, the alkali supplement tank 22 is connected to release pressure, and the inlet rotary valve is adjusted again after the system is stable;

[0059] (3) When the oxygen radical elimination catalytic converter is operated, the H2O2 concentration detector arranged on each branch is used to monitor the excessive oxygen radical content at the outlet, and then the operation and maintenance mode is entered, that is, the branch is disconnected, the other oxygen radical catalytic converter is switched to operate, the electromagnetic valves at the outlet of the alkali supplement tank and the inlet of the pollution discharge system on the corresponding branch are opened, the alkali solution is introduced to backwash the oxygen radical catalytic converter on the disconnected branch, and is introduced into the pollution discharge system; if the H2O2 concentration detector detects that the content of the oxygen radical is still excessive, the electromagnetic valve of the corresponding branch is closed and the catalyst is replaced.

[0060] For example, when the operation and maintenance state is entered, if the first H2O2 concentration detector detects that the content of the oxygen radical at the outlet of the first oxygen radical elimination catalytic converter is excessive, the third electromagnetic valve 26 corresponding to the outlet of the alkali supplement tank on the branch is opened, the alkali solution is introduced from the alkali supplement tank to backwash the first oxygen radical catalytic converter, the second rotary valve is rotated to adjust the cross-sectional area of the inlet to the maximum, the sixth electromagnetic valve 29 corresponding to the inlet of the pollution discharge system on the branch with excessive oxygen radical content is opened, the content of the oxygen radical in the first oxygen radical elimination catalytic converter is monitored by the first H2O2 concentration detector, and when the content of the oxygen radical is less than the required value, the operation is restored, if the content of the oxygen radical is still excessive after backwashing for a period of time, manual disassembly and operation and maintenance are performed.

[0061] It is to be understood that the present application is described by way of example only, and that modifications or alterations can be made to the features and embodiments described without departing from the spirit and scope of the application. Although embodiments of the present application have been disclosed in connection with the enumerated embodiments, the present application is not limited to those embodiments. Rather, it is intended to embrace all alternatives, modifications and substitutions as is permitted by the scope of the claims and equivalents thereof.

Claims

1. An oxygen radical elimination catalytic converter characterized by, The application relates to a horizontal assembly type shell, a sleeve coaxially arranged in the shell and a plurality of catalytic units, one end of the shell is sealed by a valve core, the other end is sealed and provided with a shell outlet; the sleeve is a hollow sealed cavity structure, one end of the sleeve close to the valve core is tightly and sealingly arranged with the valve core, a plurality of feeding ports are arranged on the one end of the sleeve close to the valve core, a plurality of communication holes are arranged on the valve core and communicate with the feeding ports; a plurality of baffles are sequentially, spacedly and staggeredly arranged on the inner wall of the sleeve; an exhaust port and a liquid discharge port are respectively arranged on the one end of the sleeve close to the shell outlet; a plurality of catalytic units are sequentially, spacedly and parallelly arranged between the sleeve and the shell outlet for layered treatment of gas and liquid, the catalytic unit comprises two catalytic coating layers arranged symmetrically upwards and downwards, the pore diameters of the plurality of catalytic units sequentially decrease along the gas and liquid flow direction, and the pore diameters of the two catalytic coating layers of the same catalytic unit decrease from bottom to top; the communication holes are communicated with the anode side outlet of an electrolytic cell of an electrolytic hydrogen production system, so that a mixture of alkali liquor and gas is introduced into the sleeve through the feeding ports, the exhaust port is used for introducing gas and small-particle-diameter alkali liquor into the upper catalytic coating layer of the catalytic unit, and the liquid discharge port is used for introducing alkali liquor into the lower catalytic coating layer. The sleeve is rotationally arranged, so that the through area size between the communication holes and the feeding ports is adjusted. The inner wall of the shell is provided with a baffle at the positions corresponding to the exhaust port and the liquid discharge port, the baffle is matched with the sizes of the exhaust port and the liquid discharge port and is used for adjusting the flow area of the exhaust port and the liquid discharge port through the rotation of the sleeve to adapt to the gas-liquid mixture flow generated under different loads of the electrolytic cell.

2. The oxygen radical elimination catalytic converter of claim 1, wherein, The plurality of feeding ports are symmetrically arranged along the vertical axis of the sleeve, an included angle is arranged between the central axis of the baffle and the vertical axis of the sleeve, and the included angle is 30-45 degrees.

3. The oxygen radical elimination catalytic converter of claim 1, wherein, The plurality of baffles are arranged on the liquid discharge port side and the exhaust port side of the sleeve respectively and extend towards the center of the sleeve, the baffles are semicircular and the bottom radius of the baffles is equal to the radius of the sleeve, and a plurality of filtering holes are arranged on the baffles for filtering the alkali liquor.

4. The oxygen radical elimination catalytic converter of claim 1, wherein, The two catalytic coating layers of the catalytic unit are provided with a spacing, and the adjacent catalytic units also have a spacing, so as to balance the pressure drop of the gas and liquid in the treatment process.

5. An alkaline water electrolysis hydrogen production system equipped with the oxygen radical elimination catalytic converter according to any one of claims 1 to 4, characterized in that, The application relates to an electrolytic cell, a catalytic conversion module, an alkali supplement tank and a gas-liquid separator, the feeding port of the catalytic conversion module is connected with the anode side outlet of the electrolytic cell, the outlet of the catalytic conversion module is connected with the feeding port of the anode side gas-liquid separator and the alkali supplement tank, the catalytic conversion module comprises at least two oxygen radical elimination catalytic converters with the same alkali liquor flow range, the oxygen radical elimination catalytic converters are parallelly arranged to form at least two catalytic conversion branches, electromagnetic valves are arranged on the electrolytic cell anode side outlet pipeline, the anode side gas-liquid separator feeding port pipeline, the alkali supplement tank pipeline and the two catalytic conversion branch outlet pipelines, a rotary valve is arranged on the two catalytic conversion branch inlet pipelines, and flow detectors are arranged on the at least two catalytic conversion branches for detecting the flow before and after the corresponding oxygen radical elimination catalytic converter.

6. The hydrogen production system by alkaline water electrolysis mounted with an oxygen radical elimination catalytic converter according to claim 5, characterized by, Both of the two catalytic conversion branch outlets are provided with H2O2 concentration detectors, the alkali supplement tank is connected to an alkali liquor circulation controller, and a sewage system is also connected to the anode side outlet of the electrolytic tank, and an electromagnetic valve is also arranged on the pipeline of the sewage system.

7. The control method of the alkaline water electrolysis hydrogen production system according to claim 6, characterized by, The method comprises the following steps: Step one, the electrolytic tank is operated, the generated gas and the circulating alkali liquor enter the catalytic conversion module from the anode side outlet, the flow of the gas-liquid mixture is distributed by the rotary valve control of the two catalytic conversion branches, and then enters the oxygen free radical elimination catalytic converter of the corresponding branch; Step two, one or more oxygen free radical elimination catalytic converters are operated, the outlet alkali liquor flow is detected by the corresponding flow detector, if it is lower than the limit demand set under the current working condition, the rotary valve at the inlet of the branch is controlled to increase the flow of the gas-liquid mixture, if it is higher than the limit demand set under the current working condition, the rotary valve at the inlet of the branch is controlled to reduce the flow of the gas-liquid mixture, until the set demand is reached.

8. The control method of the alkaline water electrolysis hydrogen production system according to claim 7, characterized by, Further comprising: When the oxygen free radical elimination catalytic converter is operated, the oxygen free radical content at the outlet is monitored by the H2O2 concentration detector arranged on each catalytic conversion branch, if it exceeds the set limit value, the operation and maintenance mode is entered, i.e. the catalytic conversion branch is closed, the other catalytic conversion branch is opened, the electromagnetic valves on the branch of the alkali supplement tank and the sewage system corresponding to the catalytic conversion branch in the operation and maintenance mode are opened, the oxygen free radical catalytic converter in the operation and maintenance mode is back-flushed, until the oxygen free radical content is less than the demand value, and then the operation is restored, if the oxygen free radical content still exceeds the limit value after a period of back-flushing, manual disassembly and operation and maintenance are performed.

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