In the context of the current energy transition, hydrogen energy, as a clean, efficient, and sustainable energy carrier, is gradually becoming a research hotspot in the global energy sector. Potassium hydroxide (alkaline) electrolysis for hydrogen production, as a mature hydrogen production technology, plays an important role in large-scale industrial hydrogen production. During the potassium hydroxide (alkaline) hydrogen production process, the JONSN precision-grade micro magnetic gear pump offers advantages such as stable flow, high pressure, leak-free operation, corrosion resistance, safety, and long service life, providing strong support for the optimization and efficiency enhancement of the potassium hydroxide electrolysis hydrogen production process.

1.Current Status of the Potassium Hydroxide Electrolysis Hydrogen Production Industry

At present, hydrogen production mainly involves several technological routes, including alkaline water electrolysis (ALK), proton exchange membrane (PEM), anion exchange membrane (AEM), and solid oxide electrolysis (SOEC). We will focus on analyzing alkaline electrolysis technology and pump selection. The main advantages of alkaline electrolysis technology lie in its maturity and lower costs, making it more suitable for large-scale and continuous hydrogen production. This process uses a 30% by weight potassium hydroxide solution or a 26% sodium hydroxide aqueous solution as the electrolyte, commonly referred to as alkaline solution, and employs PPS membranes or composite membranes as separators. The anode and cathode are separated, and direct current is applied to the two core metal electrodes, which decomposes water molecules into hydrogen and oxygen gases. Under the influence of direct current, water molecules at the cathode are decomposed into hydrogen ions and hydroxide ions. The hydrogen ions gain electrons to form hydrogen atoms, which further combine to generate hydrogen molecules. The hydroxide ions, under the action of the electric field, pass through the porous separator to reach the anode, where they lose electrons to form water molecules and oxygen molecules. The corresponding chemical reactions at the cathode and anode are the oxygen evolution reaction at the anode and the hydrogen evolution reaction at the cathode.

The alkaline electrolysis hydrogen production technology has shortcomings in terms of energy consumption, gas purity, and safety.

I. High energy consumption, high resistance, and low current density can lead to low production efficiency.

II. Low gas purity; large pore sizes in the membrane can result in gas impurities, and the slow start-stop process requires a longer preheating time. Therefore, it is not well-suited for renewable energy sources like wind and solar that experience significant load fluctuations. Additionally, its size and weight are relatively large, making miniaturization difficult.

III. Safety concerns arise from the inability to respond quickly to start-stop commands. It is essential to maintain a balance of pressure on both the cathode and anode sides of the electrolytic cell at all times to prevent hydrogen and oxygen from passing through the porous membrane and mixing, which could lead to ex-proof.

IV. The operating temperature of the alkaline cell is between 70 to 90 degrees Celsius. Once it stops and needs to be restarted, it takes a considerable amount of time to raise the temperature of the electrolytic cell back to the required 70 to 90 degrees Celsius.

V. Intermittent operation caan lead to the electrolytic cell's temperature remaining consistently below the working temperature, which will affect the electrolysis efficiency and also increase energy consumption

Regarding to the market, due to the continuous rise in global demand for clean energy, the market size of this industry is expanding, attracting numerous enterprises to participate. In terms of the policy environment, countries are increasingly proposing policies to support the development of hydrogen energy, creating favorable conditions for the potassium hydroxide electrolysis hydrogen production industry. However, this also raises higher requirements for safety, environmental protection, and other aspects. The potassium hydroxide electrolysis hydrogen production industry is full of opportunities but also faces many challenges. Future development will require joint efforts and continuous innovation from all parties involved.

Application of Pumps in the Potassium Hydroxide Electrolysis Hydrogen Production Industry 

In the potassium hydroxide electrolysis hydrogen production industry, pumps play a crucial role. The electrolysis of potassium hydroxide for hydrogen production involves applying direct current to an electrolytic cell, causing the potassium hydroxide solution to undergo an electrolysis reaction, generating hydrogen gas at the cathode and oxygen gas at the anode. This process requires precise control of parameters such as the flow rate, pressure, and concentration of the electrolyte to ensure the efficient and stable progression of the electrolysis reaction.

As one of the core moving components in the potassium hydroxide electrolysis hydrogen production process, pumps are required to continuously circulate the electrolyte throughout the year without downtime, ensuring uniform concentration and stable temperature within the electrolytic cell. The pump responsible for circulating the potassium hydroxide solution ensures that the electrolyte is evenly distributed within the electrolytic cell, thereby enhancing electrolysis efficiency and hydrogen production quality. Selecting a gear pump that operates stably, efficiently, and safely during the potassium hydroxide electrolysis hydrogen production process is of utmost importance. What type of pump is suitable for potassium hydroxide electrolysis hydrogen production?

In general, when selecting a gear pump for circulating the electrolyte in the potassium hydroxide electrolysis hydrogen production industry, the following points should be considered:

1. Quality, safety, and reliability; stable and efficient operation

2. Temperature resistance

3. High pressure

4. Leak-free operation

5. Corrosion resistance

(1) A horizontal comparison of traditional volumetric pumps mainly

includes electronic diaphragm pumps, screw pumps, and ordinary gear pumps.

Electronic diaphragm pumps belong to the plunger-type reciprocating pumps, which deliver pressure pulses and cannot meet the requirements for continuous delivery. The diaphragm may experience fatigue, rupture, and other issues during long-term use, resulting in poor safety. Additionally, they cannot satisfy the continuous operation process requirements throughout the year without downtime.

Screw pumps and ordinary gear pumps are both classified as volumetric rotary pumps. Traditional rotary pumps use metal rotors, which lack self-lubricating properties and are suitable for transporting viscous media. They are also relatively large in size. The manufacturing process of screw pumps is comparatively complex, leading to higher costs. Their structure is intricate, and once a fault occurs, maintenance can be quite challenging. They are prone to wear and failure due to impurities in the media. Furthermore, their performance may be affected under high-pressure conditions.

Is there a more suitable option for the electrolysis of potassium hydroxide for hydrogen production?

The emergence of micro magnetic gear pumps perfectly addresses the issues of pressure fluctuations, media leakage, and corrosion in the electrolysis solution of potassium hydroxide. Micro magnetic gear pumps feature characteristics such as non-pulsating flow, high linearity, high pressure difference, no leakage, and precise metering. Next, we will focus on analyzing micro magnetic gear pumps.

(2) Vertical Analysis of the Characteristics of Various Micro Magnetic Gear Pumps

Before understanding micro magnetic gear pumps, it is essential to know about the core gear material PEEK. Since the advent of PEEK special engineering plastics, PEEK has been successively applied in fields such as precision structural components, seals, bearings, and gears. With the development of various modified additives (such as carbon fiber, molybdenum disulfide, glass fiber, PTFE, and ceramics), different formulations of PEEK have emerged, each with varying properties. Compared to pure PEEK, these modified versions exhibit higher mechanical strength and better wear resistance. PEEK filled with ceramic additives can have a lifespan more than five times that of pure PEEK, making it suitable for use in various harsh working conditions.

Micro gear pumps have developed based on PEEK modification technology, allowing them to operate under low viscosity or even non-lubricated conditions. Additionally, the design incorporates a magnetic coupling, enabling high-pressure operation without leakage.

Currently, various domestic and international manufacturers are pursuing different technical routes for micro magnetic gear pumps:

1. Breakthroughs in the modification of PEEK gear shaft materials and processing techniques;

2. Breakthroughs in the materials and processing techniques of PEEK sliding bearings;

3. Improvements in the structural design of micro magnetic gear pumps.

Years of research and experience in micro magnetic gear pumps have shown us that if the overall design direction is incorrect, the pump's precision, performance, and lifespan will be significantly compromised.

I. Breakthroughs in the Modification of PEEK Gear Shaft Material and Processing Technology

 The gear shaft material is divided into two parts: the gear section and the shaft section.

Option 1: Traditional European and American gear pumps (and some domestic gear pump manufacturers) primarily use ordinary PEEK filled with carbon fiber for the gear material, while the shaft is made of stainless steel 316L. This configuration is suitable for applications with lower loads. The gears are injection molded into cylindrical shapes and then processed with hobbing. Ordinary PEEK filled with carbon fiber is easy to process and can achieve reasonable precision; however, the 316L stainless steel shaft is relatively soft. After approximately 5-6 months of operation, the shaft will gradually wear down, leading to significant gear runout and wear, ultimately damaging both the pump body and the gears. This issue may not be apparent during short-term use.

Traditional PEEK + Stainless Steel Shaft Surface Wear Condition

The second option: The gear material is made of imported high-strength, wear-resistant PEEK, while the shaft is made of zirconia nano-ceramic material. Due to the high difficulty of machining PEEK, many gears are formed using one-time injection molding. However, injection molding is susceptible to deformation from temperature variations, resulting in poor consistency of gears across different batches, which affects flow rates and leads to lower production costs.

JONSN Imported PEEK + Nano Ceramic Shaft

The third solution: JONSN precision-grade micro gear pump gear shaft, with gears made from high-strength, wear-resistant PEEK material imported from the UK, and the shaft made from zirconia nano-ceramic material. The gears undergo precision CNC gear finishing, addressing the processing issues of imported high-strength, wear-resistant PEEK gears by improving the tool material coating and strictly controlling the tool processing time. Additionally, the tooth profile is shaped through several hours of high-temperature molding and heat treatment, resulting in high gear precision, stable dimensions, smooth surfaces, high consistency, and long service life. The downside is the high cost, making it suitable for heavy-load, high-precision applications.

II. Breakthroughs in PEEK Sliding Bearing Materials and Processing Technology

Traditional bearing materials mainly use ordinary PEEK filled with carbon fiber, which is easy to process but has weak wear resistance and load-bearing performance, making it suitable only for light-load conditions.

The JONSN precision-grade micro gear pump sliding bearing is made from a special modified PEEK-based composite with a nano-level ceramic formulation, utilizing a dedicated processing and molding technology. It has high strength and strong dry friction resistance, making it suitable for heavy-load applications, with a lifespan exceeding 20,000 hours.

 III. Improvements in the Structural Design of Micro Magnetic Gear Pumps The structural design of traditional micro gear pumps has continued the American design from over 20 years ago (three-section structure + PTFE diaphragm sealing design). The gap between the two ends of the gears is easily affected by the thickness of the sealing gasket, leading to significant internal leakage, poor delivery accuracy, and low working efficiency. The structure is as follows:

Three-stage structural design

The design of the JONSN micro gear pump features a two-stage structure combined with a static sealing ring (see image below). Its advantages include:

(1) High assembly precision of gear shaft;

(2) Reduce the number of sealing rings and reduce the leakage points;

(3) The gaps between gears and cavities are completely guaranteed by machining precision, with high matching precision and consistency. There is no need for manual grinding and repair of gears and cavities. The more manual intervention, the worse the consistency;

(4) The internal structure adopts a large-diameter flow channel design to reduce fluid movement resistance and high conveying efficiency;

(5) Modular design, the motor can be selected according to the equipment space requirements, DC 24V, AC 380V or 440V motor;

The micro magnetic gear pump is a positive displacement pump that relies on magnetic coupling transmission. It consists of a pump body, a driving gear, an idle gear, a magnetic coupler and a drive motor. Its working principle is to bring the liquid in the suction chamber to the discharge chamber through the rotation of the gear, thereby realizing liquid transportation.

Compared with traditional mechanical seal pumps, JONSN precision micro magnetic gear pumps have the following significant features:

No leakage: Magnetic coupling transmission avoids the problem of shaft seal leakage, effectively prevents electrolyte leakage, and ensures the safety and environmental protection of the production process.

High precision: It can accurately control the flow rate with a small error range, meeting the high-precision flow control requirements of the potassium hydroxide electrolytic hydrogen production process.

Corrosion resistance: Special materials and coatings are used to withstand the strong corrosion of potassium hydroxide electrolyte, extending the service life of the pump.

Low noise: Smooth operation and low noise, reducing the impact on the working environment.

Solutions of the JONSN-MR Series Precision Micro Magnetic Gear Pump in the Electrolytic Hydrogen Production Industry Using Potassium Hydroxide (Alkaline Solution)

According to customer working conditions requirements in the potassium hydroxide electrolysis hydrogen production industry:

Circulation pump, medium: 30% alkali solution, around 85°C, flow rate 5L/min, outlet pressure 1bar.

Combined with the gear pump selection application software developed by JONSN to simulate and calculate working conditions, MRVC220 is equipped with a 24V150W DC brushless motor, which can meet the usage requirements.

The system selection plan is as follows:

Jonsn application engineers believe that the process of hydrogen production by potassium hydroxide electrolysis is a complex calculation process. At present, the quality of circulating pumps at home and abroad is also uneven. It is very important to choose a precision gear pump with reliable and stable quality. The use risk can be reduced by simulating the working conditions through the selection application software.

Some hydrogen production industry performance:

Tianjin ** Hydrogen Energy Co., Ltd. Model: MRV220 Quantity: 300 units July 2024 Stable operation

JONSN has obtained the approval of many classification societies, and the whole series of products have obtained the type certification of CCS China Classification Society.

Relevant certificates:

Introduction to the development of JONSN

Founded in 2010, JONSN is a company focusing on the research and development, production and sales of gear pumps. Since its inception, we have taken "carefully and attentively making every precision gear pump" as our business philosophy. We have gear pump assembly lines, as well as gear hobbing, gear grinding, surface grinding machines, CNC machine tools, machining centers, multi-station comprehensive testing platforms, tests and other professional equipment.

Since the changes in the domestic and foreign market environment in 2019, Jonsn has made new plans to establish a new factory in the central region. Thanks to Ganzhou's high-quality business environment and Ganzhou's gear industry supporting processing capabilities, the new factory was officially settled in Ganzhou Economic and Technological Development Zone in 2020. The factory has passed the German Rhine TUV ISO9001-2015 quality management system certification, China CCS, France BV, the United States ABS, Japan NK and other classification society quality certification, and has obtained a number of patented technologies. The company has an excellent R&D and innovation team, and cooperates with foreign companies. With the rich experience we have accumulated in the field of gear pumps over the years, through technological innovation, the use of new processes and new materials, the optimization of the pump structure, the improvement of the quality and technical level of gear pumps, and major breakthroughs in many key technical fields of precision gear pumps, JONSN gear pumps have become key control equipment for online transportation in many high-end manufacturing industries.

JONSN is a micro gear pump company that entered the field of potassium hydroxide electrolysis hydrogen production earlier in China. It occupies a large market share in the field of potassium hydroxide electrolysis hydrogen production industry and has professional and mature solutions.

JONSN-MR precision micro gear pump has the following advantages in the potassium hydroxide electrolysis hydrogen production industry:

1. Simple structure: The structure of the gear pump is relatively simple, easy to manufacture and maintain, reducing equipment costs and maintenance difficulties.

2. Stable delivery and wide application range: It can provide continuous and stable flow output in different intervals such as 60L/h, 200L/h, 600L/h, 1500L/h, 2800L/h, 3600L/h, etc., which is conducive to the smooth progress of the electrolysis process. It can handle alkaline solutions of different concentrations and temperatures and has good versatility.

3. Corrosion resistance: Since the working medium is corrosive, the pump body and gears should be made of materials resistant to strong alkali corrosion, such as stainless steel 316L or Hastelloy.

4. Good sealing: The high-quality mechanical seal or magnetic seal of the JONSN precision micro gear pump can effectively prevent the leakage of potassium hydroxide solution and gas, ensuring the safety and stability of the working environment.

5. High precision and high stability: JONSN precision micro gear pump can provide accurate and stable flow output to meet the strict requirements of electrolytic hydrogen production process for electrolyte supply.

6. High temperature resistance: Considering the heat that may be generated during the electrolysis process, JONSN precision micro gear pump has good high temperature resistance to ensure normal operation in high temperature environment.

Overall, the application of JONSN-MR precision micro gear pump in potassium hydroxide electrolysis hydrogen production industry has obvious advantages. Its reliable quality and quality enable it to operate stably and efficiently, high-precision control ensures the exhaust gas treatment effect, corrosion resistance improves the reliability of the equipment, and low noise and vibration improve the working environment and operating comfort. It is an ideal solution for potassium hydroxide electrolysis hydrogen production industry!