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

Abstract

According to the oxygen free radical elimination catalytic converter, the alkaline water electrolysis hydrogen production system and the control method, oxygen free radicals generated on the anode side are captured, meanwhile, through the arrangement of a feeding port, a partition plate structure and the like, the flow area is regulated and controlled according to the load of an electrolytic bath, the volume flow of a gas-liquid mixture is dynamically regulated and controlled, and the oxygen free radicals generated on the anode side are eliminated. And the risk of bubble blockage and the pipeline pressure drop are reduced. The catalytic unit is divided into three layers according to the components of the oxygen free radicals, various components of the oxygen free radicals existing in the fluid are treated stage by stage, and the capture efficiency of the catalytic converter on the oxygen free radicals is improved. The catalytic conversion module is composed of two or more oxygen free radical catalytic converters which operate alternately, an alkali supplementing box is arranged at an outlet of the catalytic conversion module to serve as a backwashing module, the oxygen free radical catalytic converters after operation are washed and subjected to operation maintenance, and the capture efficiency of the catalytic converters on oxygen free radicals is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production by alkaline water electrolysis, and more specifically to an oxygen free radical elimination catalytic converter, an alkaline water electrolysis hydrogen production system, and a control method. Background Art

[0002] As a clean and efficient energy carrier, hydrogen is considered an important component of the future energy system. Hydrogen production technologies are categorized into blue hydrogen, gray hydrogen, and green hydrogen, depending on the production process and by-products. Among the numerous hydrogen production technologies, water electrolysis has garnered widespread attention due to its environmental and sustainability characteristics. Among these, alkaline water electrolysis hydrogen production technology is the most mature due to its low equipment costs and long history of development. Its industrialized economy is extensive, making it suitable for large-scale hydrogen production in the industrialized process. The stability of the alkaline water electrolysis hydrogen production process also supports coupling with intermittent renewable energy sources such as solar and wind power, alleviating pressure on the power grid.

[0003] Affected by the characteristics of electrolysis reaction and complex electrolyte environment factors, the electrolysis efficiency of alkaline water electrolysis system is less than 100% during operation, and it is inevitable to produce hydroxyl radicals on the anode side. OH , superoxide anion free radical Oxygen free radicals, such as oxygen free radicals, are highly oxidizing. They enter the electrolysis system's BoP (Balance of Plant) components with the circulating alkaline solution, attaching to the inner walls and oxidizing them. This is the fundamental cause of corrosion and reduced lifespan of the BoP components in alkaline water electrolysis hydrogen production systems. After a period of operation, the BoP component surface will detach or ions will precipitate, causing impurities in the circulating alkaline solution and collected gas. At the same time, oxygen free radicals generated on the anode side gradually deposit as the alkaline solution circulates, triggering an oxygen evolution side reaction and reducing the effective current used for the electrolysis reaction. Some oxygen free radicals, carried by microbubbles in the circulating alkaline solution, adhere to the electrode surface, corroding the catalyst layer, increasing the overpotential of the electrode reaction, and reducing electrolysis efficiency.

[0004] Furthermore, the purification systems of most existing alkaline water electrolysis hydrogen production systems only cool and remove alkaline impurities from the gas being separated downstream. These systems fail to consider the challenges associated with hazardous substances in the alkaline water circulation process. Furthermore, they lack equipment lifespan analysis that addresses the source, namely the electrolysis reaction. In particular, the relatively long operation and maintenance cycles of alkaline water electrolysis systems make it difficult to observe the effects of oxygen free radical corrosion in a closed environment, undoubtedly posing a potential risk to the operation of these systems.

[0005] Finally, existing inventions of alkaline water electrolysis system components lack dynamic analysis of operating condition changes. During the actual operation of the electrolyzer, the gas production rate and alkali solution circulation volume at the outlet will vary depending on the workload. The fixed-structure alkali solution filter will form a sediment layer, which affects the alkali solution circulation state. This often leads to a mismatch between the operating power and the pipeline pressure drop. The change in the alkali solution circulation state causes the concentration overpotential on the electrode surface to increase, ultimately affecting the performance of the alkaline water hydrogen production electrolyzer. With the development of industrialization, the scale of alkaline water electrolysis hydrogen production systems has gradually expanded, and the range of operating condition changes has also increased. Therefore, it is very important to develop a catalytic converter that can efficiently remove oxygen free radicals over a wide power range. Summary of the Invention

[0006] One object of the present invention is to provide an oxygen free radical elimination catalytic converter, an alkaline water electrolysis hydrogen production system, and a control method. These systems capture oxygen free radicals generated on the anode side while dynamically regulating the volume flow of the gas-liquid mixture by providing a rotary valve at the feed inlet and a baffle structure near the outlet, adjusting the flow area according to the electrolyzer load. This reduces the risk of bubble blockage and pipeline pressure drop. Baffles are installed within the sleeve to achieve preliminary separation of the gas-liquid mixture using density differences, treating the alkaline solution and gas separately. The catalytic unit is divided into three layers based on the composition of the oxygen free radicals, allowing for graded treatment of the various oxygen free radical components in the fluid, thereby improving the catalytic converter's oxygen free radical capture efficiency. The catalytic conversion module consists of two or more oxygen free radical catalytic converters, which operate alternately. A caustic refill tank is provided at the outlet of the catalytic conversion module as a backwash module to flush and maintain the oxygen free radical catalytic converters after operation, thereby improving the catalytic converter's oxygen free radical capture efficiency.

[0007] In order to solve the above technical problems, the present invention provides an oxygen free radical elimination catalytic converter, comprising a horizontally assembled shell and a sleeve and a plurality of catalytic units coaxially arranged in the shell, one end of the shell is sealed by a valve core, and the other end is sealed and provided with a shell outlet; the sleeve is a hollow sealed cavity structure, the end of the sleeve facing the valve core is tightly sealed with the valve core, a plurality of feed ports are provided on the end of the sleeve facing the valve core, and a plurality of connecting holes are provided on the valve core, which are connected with the feed ports; a plurality of baffles are sequentially spaced and staggered on the inner wall of the sleeve; the sleeve is respectively provided with a plurality of baffles at the upper and lower ends near the end facing the shell outlet An exhaust port and a drain port are provided; a plurality of catalytic units are arranged in parallel and spaced in sequence between the sleeve and the shell outlet for stratified treatment of gas and liquid, the catalytic unit includes two catalytic coatings symmetrically arranged above and below, the apertures of the plurality of catalytic units decrease in sequence along the gas-liquid flow direction, and the apertures of the upper and lower catalytic coatings of the same catalytic unit decrease from bottom to top; the communicating hole is connected to the anode side outlet of the electrolyzer of the electrolytic hydrogen production system, so as to introduce a mixture of alkali solution and gas into the sleeve through the feed port, the exhaust port is used to introduce gas and small-particle alkali solution into the upper catalytic coating of the catalytic unit, and the drain port is used to introduce alkali solution into the lower catalytic coating.

[0008] Preferably, the sleeve is rotatably arranged to adjust the size of the through area between the connecting hole and the feed port.

[0009] Preferably, the inner wall of the shell is provided with partitions at corresponding positions of the exhaust port and the drain port, which match the size of the exhaust port and the drain port and are used to regulate the flow area of ​​the exhaust port and the drain port by rotating the sleeve to adapt to the flow rate of the gas-liquid mixture generated under different loads of the electrolytic cell.

[0010] Preferably, the multiple feed ports are symmetrically arranged along the vertical axis of the sleeve, and an angle of 30° to 45° is set between the central axis of the partition and the vertical axis of the sleeve.

[0011] Preferably, a plurality of baffles are respectively arranged on the discharge port side and the exhaust port side of the sleeve and extend toward the center of the sleeve. The baffles are semicircular and the bottom circle radius is equal to the radius of the sleeve. The baffles are provided with several filter holes for filtering the alkali solution.

[0012] Preferably, a gap is provided between the upper and lower catalytic coatings of the catalytic unit, and there is also a gap between adjacent catalytic units to balance the pressure drop of gas-liquid changes during the treatment process.

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

[0014] Preferably, an H2O2 concentration detector is provided at the outlet of both catalytic conversion branches, the alkali replenishment tank is connected to the alkali solution circulation controller, and the anode side outlet of the electrolytic cell is also connected to a sewage discharge system, and an electromagnetic valve is also provided on the pipeline.

[0015] The present invention also provides a control method for an alkaline water electrolysis hydrogen production system, comprising the following steps: Step 1: The electrolyzer is in operation, and the generated gas and circulating alkaline solution enter the catalytic conversion module from the anode side outlet. The flow of the gas-liquid mixture is distributed through 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 2: One or more oxygen free radical elimination catalytic converters are operated, and the outlet alkali solution flow rate is detected by the corresponding flow detector. If it is lower than the limit demand set under the current operating conditions, the rotary valve at the inlet of the branch is controlled to increase the flow rate of the gas-liquid mixture; if it is higher than the limit demand set under the current operating conditions, the rotary valve at the inlet of the branch is controlled to reduce the flow rate of the gas-liquid mixture; until the set demand is reached.

[0016] Preferably, it also includes: When the oxygen free radical elimination catalytic converter is in operation, the oxygen free radical content at the outlet is monitored by the H2O2 concentration detector correspondingly installed on each catalytic conversion branch. If it exceeds the set limit value, the operation and maintenance mode is entered, that is, this catalytic conversion branch is closed, and other catalytic conversion branches are opened. The solenoid valves on the alkali replenishment tank and the ranking system branch corresponding to the catalytic conversion branch entering the operation and maintenance mode are opened, and the oxygen free radical catalytic converter entering the operation and maintenance mode is backwashed until the oxygen free radical content is less than the required value and then its operation is resumed. If the oxygen free radical content still exceeds the standard after backwashing for a period of time, manual disassembly and operation maintenance are carried out.

[0017] The present invention has at least the following beneficial effects: (1) The oxygen free radical elimination catalytic converter described in the present invention utilizes the linkage between the valve core and the sleeve to change the inlet mass flow of the gas-liquid mixture in real time according to the change of the output power of the electrolyzer and rotates the connected sleeve to change the contact area with the partition to adjust the flow rate of the gas and the alkaline solution, thereby ensuring the stable flow of gas and liquid in the catalytic unit under different working conditions, improving the catalytic conversion efficiency, and effectively breaking through the technical barriers of the narrow applicable working condition range and poor flexibility brought by the fixed structure of the existing alkaline water electrolysis hydrogen production system equipment, and comprehensively improving the operation cycle of the electrolysis hydrogen production system components within a wide load range (the fluctuation adaptation range is about 35%-110%).

[0018] (2) The present invention adds baffles at the top and bottom of the sleeve, which can effectively perform preliminary separation of the gas-liquid mixture at the outlet of the electrolyzer, maintain the relative stability of the subsequent flow of gas and liquid under changing working conditions, and further, the oxygen free radical catalytic converter is installed horizontally, so that the gas and alkaline solution after catalytic conversion enter the subsequent gas-liquid separator of the electrolytic hydrogen production system in a stable flow state, thereby reducing its workload and container pressure drop, thereby reducing production costs.

[0019] (3) The present invention divides the catalytic unit of the housing into three columns of catalytic units, which can capture and remove various oxygen free radical components in a graded manner. The catalytic unit is divided into two layers, upper and lower, based on the difference in flow resistance between gas and liquid in the pipeline. The pore size of the upper catalytic coating layer for treating gas is smaller than the pore size of the lower catalytic coating layer for treating liquid. The pore size of each column of catalytic units gradually decreases along the direction of gas-liquid flow, which is used to separate, aggregate, and separate bubbles that are carried or generated, thereby preventing bubble blockage during the catalytic oxidation process.

[0020] (4) The present invention sets a catalytic conversion module on the anode side of the electrolyzer of the alkaline water electrolysis hydrogen production system to purify the gas-liquid mixture in layers and grades, maintain the stability of the pipeline pressure drop, reduce the workload of the system gas-liquid separator, and fundamentally avoid the corrosion of the alkaline solution on the system components outside the electrolyzer, thereby reducing the operation and maintenance costs. The two catalytic converters of the catalytic conversion module operate alternately to capture the oxygen free radicals carried in the gas and liquid in a graded manner. At the same time, an alkali replenishment tank is set at the outlet of the catalytic conversion module as a backwash module, and the control of the branch and main solenoid valves is combined to achieve stable operation under load changes, thereby improving the service life of the catalytic converter. The catalytic efficiency of the oxygen free radical catalytic converter is detected by the concentration monitor, maintaining the stable operation of the electrolysis system under different working conditions, improving the economy of the system, and facilitating operation and maintenance.

[0021] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a perspective view of the oxygen free radical elimination catalytic converter of the present invention; Figure 2 is a cross-sectional view of the oxygen free radical elimination catalytic converter of the present invention; FIG3 is a schematic diagram of the working principle of the oxygen free radical elimination catalytic converter of the present invention; Among them, Figure 3 (a) shows the principle of the oxygen free radical elimination catalytic converter of the present invention, Figure 3 (b) shows the gas flow trace when the cross-sectional area of ​​the feed port of the oxygen free radical elimination catalytic converter of the present invention is the largest; Figure 3 (c) shows the gas flow trace when the feed port of the oxygen free radical elimination catalytic converter of the present invention is closed; Figure 4 A perspective view of the sleeve of the present invention; Figures 5-7 Schematic diagram of the apertures of the first to third catalytic units along the gas-liquid flow direction of the present invention; Figure 8 Schematic diagram of the phase angle distribution of the present invention.

[0023] Figure 9 Schematic diagram of the structure of the alkaline water electrolysis hydrogen production system of the present invention; Figure 10 This is a schematic structural diagram of the catalytic conversion module of the alkaline water electrolysis hydrogen production system of the present invention; Figure 11 This is a control block diagram of the catalytic conversion module of the alkaline water electrolysis hydrogen production system of the present invention.

[0024] Description of reference numerals: 1-Servo motor; 2-Valve core; 3-Communication hole; 4-Sealing assembly; 5-Housing; 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-Housing outlet; 14-Feed port; 15-Baffle; 16-exhaust port; 17-liquid discharge port; 18-partition; 19-electrolyzer; 20-catalytic conversion module; 21-gas-liquid separator; 22-alkali feeding tank; 23-alkali solution circulation controller; 24-first solenoid valve; 25-second solenoid valve; 26-third solenoid valve; 27-fourth solenoid valve; 28-fifth solenoid valve; 29-sixth solenoid valve; 30-first rotary valve; 31-second rotary valve; 32-first flow meter; 33-second flow meter; 34-first oxygen free radical elimination catalytic converter; 35-second oxygen free radical elimination catalytic converter; 36-first H2O2 concentration detector; 37-second H2O2 concentration detector. DETAILED DESCRIPTION

[0025] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below with reference to the accompanying drawings so that those skilled in the art can implement it according to the description.

[0026] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified; in the description of the present invention, the terms "horizontal", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0027] like Figure 1 and Figure 2 As shown, the present invention discloses a catalytic converter for eliminating oxygen free radicals in an alkaline water electrolysis hydrogen production system, comprising a shell 5, a sleeve 6, a valve core and a catalytic unit. The shell is cylindrical, one side opening is closed as a whole by a valve core 2, and 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 entire shell is a hollow sealed cavity structure. The shell is provided with a sleeve 6 axially coincident with its center, which is also a hollow sealed cavity structure. The sleeve 6 is provided with a gas-liquid separation layer, a feed port 14, an exhaust port 16 and a drain port 17. The gas-liquid separation layer is composed of a plurality of baffles 15 with filter holes, which are used to separate the gas-liquid mixture, thereby facilitating the catalytic unit to oxygenate the gas and liquid respectively. To capture and eliminate free radicals, the feed port 14 is arranged on the side of the sleeve relative to the valve core and is used to introduce a mixture of alkali solution and gas into the sleeve 6, the exhaust port 16 is used to introduce gas and small-particle alkali solution such as alkali mist into the upper catalytic coating of the catalytic unit, and the drain port 17 is used to introduce alkali solution into the lower catalytic coating; the inner wall of the shell is provided with a partition 18 near the exhaust port and the drain port, which is used to cooperate and regulate the flow area of ​​the exhaust port 16 and the drain port 17 to adapt to the flow rate of the gas-liquid mixture generated under different loads of the electrolytic cell. During the rotation of the sleeve, the exhaust port 16 and the drain port 17 come into contact with the partition 18, the flow area of ​​the gas and alkali solution changes, and the flow rate of the gas-liquid mixture generated under different loads of the electrolytic cell is changed.

[0028] like Figure 4As shown, the baffle 15 is arranged on the side of the liquid discharge port 17 and the air discharge port 16 of the sleeve 6, extending toward the center of the sleeve 6, and the baffle is adapted to the width of the sleeve 6, that is, the baffle is semicircular and the bottom circle radius is equal to the radius of the sleeve, that is, assuming that there is no filter hole, the baffle can completely block the movement of the liquid at the bottom of the sleeve. A plurality of baffles 15 are spaced apart and arranged relatively to each other, and the baffle 15 is provided with several 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, and the gas-liquid mixture can achieve effective gas-liquid stratification after flowing through the catalytic converter of the present invention, thereby reducing the workload 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 its production cost.

[0029] The valve core 2 is installed at one end of the feed port 14 of the rotatable sleeve 6. A sealing component 4, such as a sealing gasket, is provided between the valve core 2 and the sleeve 6 to prevent leakage of alkali solution and gas. The valve core 2 is rotatably connected to 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 feed ports 14 with phase angle distributions. The valve core 2 is a plate-like structure with multiple connecting holes 3 provided thereon and connected to the anode side outlet of the electrolyzer of the electrolytic hydrogen production system. Through the rotation of the sleeve 6, the sleeve feed ports 14 with different phase angle distributions are fully or partially connected to the corresponding multiple connecting holes 3 on the valve core 2, which is used to preliminarily control the flow rate and speed of the gas-liquid mixture entering the sleeve. The vertical axis of the sleeve is Figure 8 As shown in the figure, the vertical axis of the sleeve cross section passes through the center point. The drain port and the exhaust port are located just at the upper and lower ends of the vertical axis.

[0030] The inner wall of the shell 5 is provided with a partition 18 at the corresponding position of the exhaust port and the drain port. The contact area between the partition 18 and the drain port 17 and the exhaust port 16 is changed by rotating the sleeve, thereby changing the flow rate of the liquid and gas entering the catalytic coating. Figure 8 As shown, an angle is set between the central axis of the partition 18 and the vertical axis of the sleeve to form a phase angle difference, preferably 30° to 45°, to adapt to the control of the gas and liquid flow rate after separation under the change of the flow rate of the gas-liquid mixture, and to strengthen the subsequent catalyst layer to capture and eliminate oxygen free radicals for impurities present in the alkali solution and gas. If no angle is set between the central axis of the partition 18 and the vertical axis of the sleeve, the same angle is maintained, the baffle is placed horizontally, the exhaust port and the drain port of the partition and the sleeve coincide, the exhaust and drain rates are reduced, and blockage may occur in severe cases, so a certain phase difference is set for the partition and the sleeve. The basis for setting the range of the phase angle difference between the partition and the sleeve is: by calculating the blocking area of ​​the partition to the exhaust (liquid) port under the condition of the maximum feed port area, the phase angle between the partition and the feed port is adjusted, and the relatively optimal phase angle deviation is found through multiple iterative calculations.

[0031] The multiple feed ports are symmetrically arranged along the vertical axis of the sleeve, with the purpose of being applied to larger-scale AWE systems to process a higher flow rate of gas-liquid mixture at the anode side outlet of the electrolyzer. The feed ports and connecting holes of this application are described as two as an example. If the number of feed ports is increased, that is, the area of ​​the gas-liquid mixture to be processed is increased, the contact area between the exhaust port, the drain port and the partition will be increased, and the size and area of ​​the partition and the exhaust port and the drain port will also be adjusted accordingly.

[0032] The shell 5 includes three catalytic units arranged in parallel near the outlet end. The catalytic units have two upper and lower catalytic coatings, which are symmetrically arranged along the horizontal axis of the sleeve cross section to respectively process the gas after the initial gas-liquid separation of the sleeve and the impurities carrying alkaline mist, as well as the oxygen free radical components contained in the alkaline solution. A height of 3-5 mm is left in the middle of the catalytic coating, and a spacing of 5-7 mm is left between the catalytic units to balance the pressure drop of the gas-liquid changes during the treatment process.

[0033] The catalytic units included in the housing 5 are named as the first catalytic unit, the second catalytic unit and the third catalytic unit respectively along the gas-liquid flow direction, and are used to gradually process the various oxygen free radical components enriched by the reaction on the anode side. The pore sizes of the three alkali liquid 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 FIG. Figure 5 、 Figure 6 and Figure 7 As shown, bubbles carried in the alkali solution aggregate into larger bubbles upon contact with the small pores, which are then desorbed, separated, and discharged from the liquid, effectively avoiding bubble blockage in the catalytic unit. Depending on the operating conditions of the electrolyzer, the pore size of the bubbles in the gas-liquid mixture at the electrolyzer outlet ranges from 200 to 500 μm. After passing through the apertured baffles, the bubbles rupture and reform, reducing their size by approximately 70%. As a result, the bubble diameter decreases to 60 μm to 150 μm when flowing through the underlying liquid catalytic coating.

[0034] The first catalytic unit includes an alkaline liquid catalytic coating (first liquid catalytic conversion layer 10) equipped with a Pt / C catalyst and a porous titanium gas diffusion catalytic coating (first gas catalytic conversion layer 7), which is used to preferentially decompose H2O2 and prevent the subsequent decomposition of H2O2 with the volatilization of high-temperature alkaline liquid to produce OH, which corrodes metal pipes and sealing materials.

[0035] The second catalytic unit includes an alkaline liquid catalytic coating layer (second liquid catalytic conversion layer 11) carrying a Mn / C catalyst and a Pt / C catalyst, and a porous titanium gas diffusion catalytic coating layer (second gas catalytic conversion layer 8) subjected to a surface sulfonation treatment. The surface sulfonation treatment process is to introduce Group, enhance electrostatic adsorption; equipped with a Pt / C catalyst alkali catalytic coating 11 and porous titanium gas diffusion catalytic coating 8 is to decompose the disproportionation reaction to re-produced H2O2.

[0036] The third catalytic unit includes a The alkaline liquid catalytic coating (the third liquid catalytic conversion layer 12) and the porous gas diffusion catalytic coating (the third gas catalytic conversion layer 9) are used to remove ·OH. The pore size of the alkaline liquid and the gas catalytic coating is the smallest, which can eliminate bubbles in the alkaline liquid to the greatest extent, prevent ·OH from entering the downstream of the alkaline water electrolysis hydrogen production system with the bubbles, and prevent the bubbles from clogging the catalytic converter.

[0037] A spring clip is provided at the connection between the housing of the oxygen free radical elimination catalytic converter and the catalytic unit to achieve a detachable connection. When abnormal pressure difference occurs during operation, the catalytic efficiency is attenuated, or the response capability to special working conditions is reduced, resulting in poor working efficiency of the catalytic converter, the operation and maintenance personnel can directly dismantle the catalytic unit from the outside.

[0038] Oxygen free radical elimination catalytic converter working process: As shown in Figure 3 (a), the working principle diagram of the oxygen free radical elimination catalytic converter of the present invention is shown. When the electrolytic cell is in operation, a gas-liquid mixture composed of the gas generated at the electrode and the circulating alkaline solution introduced into the electrolytic cell is discharged from the outlet of the electrolytic cell. The gas-liquid mixture enters the sleeve from the feed port and undergoes preliminary gas-liquid separation through the baffle of the sleeve. After passing through the baffle, the preliminarily separated alkaline solution moves along the holes of the baffle and gradually settles and gathers at the bottom of the sleeve. It is discharged through the drain port at the bottom of the sleeve and enters the bottom of the catalytic unit of the catalytic converter housing. It flows through the lower layers of the first catalytic unit, the second catalytic unit and the third catalytic unit, respectively treating the presence of the free radicals in the alkaline solution. and The gas, small-particle alkali solution and alkali mist separated in the sleeve baffle are discharged through the exhaust port 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 respectively and The capture and elimination are carried out, and then the catalytic converter flows out through the shell outlet. The gravity potential energy generated by the agglomeration of the attached alkali mist and droplets combined in the pore size is used to make them fall to the flowing alkali liquor, so as to realize the gas-liquid layering and effectively control the content of the alkali liquor impurities carried by the gas at the shell outlet. 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 as to improve the catalytic conversion efficiency by changing the gas-liquid flow time, and stabilize the pipeline pressure drop. 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, and the present application controls the flow area by keeping the flow velocity unchanged (such as 2 m / s) and controlling the size of the inlet.

[0039] The application also 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 FIG. 1, an oxygen radical corrosion elimination alkali electrolysis 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.

[0040] The alkali supplement tank 22 is connected to the outlet of the catalytic conversion module and the feed port of the anode-side gas-liquid separator 21 through a third solenoid valve, forming a backwash module; the alkali flowmeter installed in each branch of the catalytic conversion module 20 and the alkali supplement tank 22 are all connected to the alkali circulation controller 23; the alkali circulation module includes an alkali circulation pump and an alkali circulation heat exchanger, and the discharge port of the anode-side gas-liquid separator 21 is connected to the alkali circulation pump, which is connected to the electrolyzer 19 of the alkaline water electrolysis hydrogen production device through the alkali circulation heat exchanger. In the operation and maintenance mode, the alkali circulation controller 23 needs to output alkali from the alkali supplement tank for sewage discharge; in the working mode, the alkali circulation controller 23 needs to adjust the alkali in and out of the alkali supplement tank and keep the alkali flow of the alkali circulation system stable.

[0041] like Figure 10 As shown, the catalytic conversion module 20 includes at least two oxygen free radical elimination catalytic converters with the same alkali liquid flow range, the oxygen free radical elimination catalytic converters are arranged in parallel, and during the process, at least one oxygen free radical elimination catalytic converter is in operation; this application is described by setting two oxygen free radical elimination catalytic converters as an example. The first catalytic conversion branch is provided with a first rotary valve 30, a first oxygen free radical elimination catalytic converter 34, and a first flow meter 32 for detecting the flow before and after the first oxygen free radical elimination catalytic converter 34, and a first solenoid valve 24. The second catalytic conversion branch is provided with a second rotary valve 31, a second oxygen free radical elimination catalytic converter 35, and a second flow meter 33 for detecting the flow before and after the second oxygen free radical elimination catalytic converter, and a second solenoid valve 25. The outlets of the two catalytic conversion branches are respectively provided with a first H2O2 concentration detector 36 and a second H2O2 concentration detector 37. The first H2O2 concentration detector is added between the first solenoid valve and the first oxygen free radical elimination catalytic converter, and the second H2O2 concentration detector is added between the second solenoid valve and the second oxygen free radical elimination catalytic converter. The first flow detector and the second flow detector of the present application are flow meters when actually used.

[0042] like Figure 11 As shown, the present invention also discloses a control method for an alkaline water electrolysis system for eliminating oxygen free radical corrosion. The method is used to control the above-mentioned oxygen free radical catalytic conversion module. During operation, at least one oxygen free radical elimination catalytic converter is in operation. The method comprises the following steps: (1) When the electrolyzer is running, the generated oxygen and the circulating alkaline solution enter the catalytic conversion module from the anode side outlet. The flow of the gas-liquid mixture is distributed through the rotary valve control of the two branches, and then enters the oxygen free radical elimination catalytic converter of the corresponding branch; (2) The first or second or all oxygen free radical elimination catalytic converters are in operation, and the alkali flow rate at the outlet of the oxygen free radical elimination catalytic converter is monitored by an alkali flow meter. According to the number of oxygen free radical elimination catalytic converters in operation, if two oxygen free radical elimination catalytic converters are in operation, the alkali demand of the system remains unchanged and the pressure remains unchanged, then theoretically the flow rate of the two branches is about 1 / 2. Therefore, if the setting is lower than half of the circulating alkali demand of the electrolytic cell under the current working condition, the rotary valve at the inlet of the branch is controlled to increase the flow rate of the gas-liquid mixture; when the working condition of the alkaline electrolytic cell fluctuates, causing the flow rate of the gas-liquid mixture to be unstable, and the alkali flow meter detects that the content of a branch is too high, if the flow fluctuation is too large and exceeds the set value, such as more than 10%, the rotary valve at the inlet of the branch is controlled to reduce the flow rate, and the solenoid valve corresponding to the alkali replenishment tank on this branch at the outlet of the catalytic conversion module is opened, and the alkali replenishment tank 22 is connected to release the pressure, and the inlet rotary valve is readjusted after the system stabilizes; (3) When the oxygen free radical elimination catalytic converter is in operation, if the oxygen free radical content at the outlet is monitored by the corresponding H2O2 concentration detector installed on each branch and exceeds the standard, the operation and maintenance mode will be entered, that is, the branch will be disconnected and switched to other oxygen free radical catalytic converters for operation. At the same time, the solenoid valves at the outlet of the alkali replenishment tank and the inlet of the sewage system on the corresponding branch will be opened, and alkali solution will be introduced to backwash the oxygen free radical catalytic converter on the disconnected branch and then lead to the sewage system; if the H2O2 concentration detector monitors that the oxygen free radical content is still exceeding the standard, the corresponding branch solenoid valve will be closed and the catalyst will be replaced.

[0043] For example, when entering the operation and maintenance state, if the first H2O2 concentration detector detects that the oxygen free radical content at the outlet of the first oxygen free radical elimination catalytic converter exceeds the standard, the third solenoid valve 26 located at the outlet of the alkali replenishing tank corresponding to this branch is opened, and alkali solution is introduced from the alkali replenishing tank to backwash the first oxygen free radical catalytic converter. At the same time, the second rotary valve adjusts the cross-sectional area of ​​the feed port to the maximum by rotation, and opens the sixth solenoid valve 29 at the inlet of the sewage system corresponding to the branch where the oxygen free radical content exceeds the standard. The oxygen free radical content of the first oxygen free radical elimination catalytic converter is monitored by the first H2O2 concentration detector until the oxygen free radical content is less than the required value and then resumes its operation. If the oxygen free radical content still exceeds the standard after backwashing for a period of time, manual disassembly and operation maintenance are performed.

[0044] It will be understood that the present invention is described by way of some embodiments, and those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and embodiments. They can be fully applied to various fields suitable for the present invention, and further modifications can be easily implemented by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. An oxygen free radical elimination catalytic converter, characterized in that: The invention comprises a horizontally assembled shell and a sleeve and a plurality of catalytic units coaxially arranged in the shell, one end of the shell is sealed by a valve core, and the other end is sealed and provided with a shell outlet; the sleeve is a hollow sealed cavity structure, the end of the sleeve facing the valve core is tightly sealed with the valve core, a plurality of feed ports are provided on the end of the sleeve facing the valve core, and a plurality of connecting holes are provided on the valve core, which are connected with the feed ports; a plurality of baffles are sequentially spaced and staggered on the inner wall of the sleeve; an exhaust port and a liquid discharge port are respectively provided on the upper and lower ends of the sleeve close to the end facing the shell outlet; a plurality of catalytic units They are arranged in parallel and spaced apart between the sleeve and the shell outlet for stratified treatment of gas and liquid. The catalytic unit includes two catalytic coatings symmetrically arranged above and below. The apertures of multiple catalytic units decrease in sequence along the gas-liquid flow direction, and the apertures of the upper and lower catalytic coatings of the same catalytic unit decrease from bottom to top; the connecting hole is connected to the anode side outlet of the electrolyzer of the electrolytic hydrogen production system to introduce a mixture of alkali solution and gas into the sleeve through the feed port, the exhaust port is used to introduce gas and small-particle alkali solution into the upper catalytic coating of the catalytic unit, and the drain port is used to introduce alkali solution into the lower catalytic coating.

2. The oxygen free radical elimination catalytic converter according to claim 1, characterized in that The sleeve is rotatably arranged to adjust the size of the through area between the communicating hole and the feed port.

3. The oxygen free radical elimination catalytic converter according to claim 2, characterized in that: The inner wall of the shell is provided with partitions at the corresponding positions of the exhaust port and the drain port, which match the size of the exhaust port and the drain port and are used to regulate the flow area of ​​the exhaust port and the drain port through the rotation of the sleeve to adapt to the flow rate of the gas-liquid mixture generated under different loads of the electrolytic cell.

4. The oxygen free radical elimination catalytic converter according to claim 3, characterized in that The multiple feed ports are symmetrically arranged along the vertical axis of the sleeve, and an angle of 30° to 45° is set between the center axis of the partition and the vertical axis of the sleeve.

5. The oxygen free radical elimination catalytic converter according to claim 1, wherein: A plurality of baffles are respectively arranged on the drain port side and the exhaust port side of the sleeve and extend toward the center of the sleeve. The baffles are semicircular and the bottom circle radius is equal to the radius of the sleeve. The baffles are each provided with a plurality of filter holes for filtering the alkali solution.

6. The oxygen free radical elimination catalytic converter according to claim 1, wherein: A gap is provided between the upper and lower catalytic coatings of the catalytic unit, and there is also a gap between adjacent catalytic units to balance the pressure drop of gas-liquid changes during the treatment process.

7. An alkaline water electrolysis hydrogen production system equipped with an oxygen free radical elimination catalytic converter according to any one of claims 1 to 6, characterized in that: The invention comprises an electrolytic cell, a catalytic conversion module, an alkali feeding tank and a gas-liquid separator, wherein the feed port of the catalytic conversion module is connected to the anode side outlet of the electrolytic cell, and the outlet of the catalytic conversion module is connected to the feed port of the anode side gas-liquid separator and the alkali feeding tank. The catalytic conversion module comprises at least two oxygen free radical elimination catalytic converters with the same alkali liquid flow range, which are arranged in parallel to form at least two catalytic conversion branches. Solenoid valves are provided on the outlet pipe of the anode side of the electrolytic cell, the feed port pipe of the anode side gas-liquid separator, the alkali feeding tank pipe and the outlet pipes of the two catalytic conversion branches. Rotary valves are provided on the inlet pipes of the two catalytic conversion branches. Flow detectors are provided on at least two catalytic conversion branches for detecting the flow rates before and after the corresponding oxygen free radical elimination catalytic converters.

8. The alkaline water electrolysis hydrogen production system equipped with an oxygen free radical elimination catalytic converter as claimed in claim 7, characterized in that: H2O2 concentration detectors are installed at the outlets of the two catalytic conversion branches, the alkali replenishment tank is connected to the alkali solution circulation controller, and the anode side outlet of the electrolytic cell is also connected to the sewage discharge system, and a solenoid valve is also installed on its pipeline.

9. The control method of the alkaline water electrolysis hydrogen production system according to claim 8, characterized in that: The steps include: Step 1: The electrolyzer is in operation, and the generated gas and circulating alkaline solution enter the catalytic conversion module from the anode side outlet. The flow of the gas-liquid mixture is distributed through 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 2: One or more oxygen free radical elimination catalytic converters are operated, and the outlet alkali solution flow rate is detected by the corresponding flow detector. If it is lower than the limit demand set under the current operating conditions, the rotary valve at the inlet of the branch is controlled to increase the flow rate of the gas-liquid mixture; if it is higher than the limit demand set under the current operating conditions, the rotary valve at the inlet of the branch is controlled to reduce the flow rate of the gas-liquid mixture; until the set demand is reached.

10. The control method of the alkaline water electrolysis hydrogen production system according to claim 9, characterized in that: Also includes: When the oxygen free radical elimination catalytic converter is in operation, the oxygen free radical content at the outlet is monitored by the H2O2 concentration detector correspondingly installed on each catalytic conversion branch. If it exceeds the set limit value, the operation and maintenance mode is entered, that is, this catalytic conversion branch is closed, and other catalytic conversion branches are opened. The solenoid valves on the alkali replenishment tank and the ranking system branch corresponding to the catalytic conversion branch entering the operation and maintenance mode are opened, and the oxygen free radical catalytic converter entering the operation and maintenance mode is backwashed until the oxygen free radical content is less than the required value and then its operation is resumed. If the oxygen free radical content still exceeds the standard after backwashing for a period of time, manual disassembly and operation maintenance are carried out.

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