Electrolysis of Water to Produce Hydrogen

As a clean and sustainable way to produce hydrogen, electrolysis of water to produce hydrogen has shown extremely significant advantages in today’s energy field.

From an environmental protection point of view, its entire production process has the outstanding characteristics of no pollution and zero emissions. In the process of electrolyzing water, only electricity is used to decompose water into hydrogen and oxygen, without producing greenhouse gases such as carbon dioxide, sulfur dioxide or other pollutants. This characteristic makes hydrogen production from water electrolysis play a key role in addressing the serious challenge of global warming. Compared with traditional fossil fuel hydrogen production methods, it avoids the emission of large amounts of greenhouse gases during extraction, processing and conversion, reduces environmental damage from the source, and provides strong support for the ecological balance of the earth.

In terms of synergy with renewable energy, hydrogen production through electrolysis of water shows a high degree of compatibility. With the rapid development of renewable energy sources such as solar and wind energy around the world, the problems of intermittency and unpredictability of their power generation have become increasingly prominent. For example, solar power generation is affected by weather and day and night changes, while wind power generation depends on the strength and stability of the wind. The electrolysis of water to produce hydrogen technology provides an ideal way to solve this problem. When there is a surplus of renewable energy generation, the excess electricity can be efficiently used to electrolyze water to produce hydrogen, converting electrical energy into chemical energy for storage. This method of energy storage not only effectively avoids the waste of renewable energy power, but also enhances the flexibility and efficiency of the entire power system. When renewable energy generation is insufficient or power demand peaks, the stored hydrogen can be converted back into electrical energy through technologies such as fuel cells and fed back to the grid to ensure the stable operation of the grid. This process is like installing a flexibly adjustable “energy buffer” for the power system, allowing renewable energy to be better integrated into the existing energy system and improving the stability and reliability of energy supply.

Main device – electrolyzer

• Alkaline electrolyzer:
  This is a device used in the more traditional and mature water electrolysis hydrogen production technology. Its electrodes generally use nickel-based materials and other materials, and the electrolyte is usually potassium hydroxide (KOH) or sodium hydroxide (NaOH) solution, which has the advantages of relatively low cost and simple operation. However, its disadvantage is that the energy efficiency is not particularly high, and it requires the use of asbestos and other diaphragm materials, which has certain environmental and safety risks. It is currently being gradually improved. For example, it is also used in some small industrial hydrogen production scenarios or in situations where hydrogen purity requirements are not extremely high.
  Working principle: In an alkaline electrolytic cell, OH⁻ ions (from the electrolyte) will migrate to the anode and lose electrons on the anode surface to generate oxygen and water; while at the cathode, water molecules gain electrons and migrate from the anode through the separator. K⁻ (taking KOH electrolyte as an example) combines to generate hydrogen and OH⁻, thereby achieving a continuous water electrolysis process.
• Proton exchange membrane electrolyzer (PEM electrolyzer):
  It uses a proton exchange membrane as the diaphragm, and the electrodes generally use precious metal catalysts (such as platinum, etc.). This electrolytic cell has the advantages of large current density, high energy efficiency, high hydrogen purity, fast start-up and response speed, and is suitable for use in renewable energy. In scenarios where power generation (such as wind power and photovoltaics) is highly volatile, hydrogen production can be flexibly matched with intermittent power sources. However, the disadvantage is the high cost, especially the high price of proton exchange membranes and precious metal catalysts, which limits its large-scale low-cost promotion. It is often used in fields with high requirements for hydrogen quality, such as the production of hydrogen for fuel cell vehicles.
  Working principle: In the PEM electrolyzer, water is oxidized on the anode surface to generate oxygen, protons (H⁺) and electrons. The protons migrate to the cathode in the form of hydronium ions (H₃O⁺) through the proton exchange membrane, and electrons are obtained on the cathode surface. Reduction produces hydrogen gas.
• Solid Oxide Electrolyzer (SOEC):
  The working temperature is relatively high (generally around 600℃-1000℃). It uses ceramic materials as electrolytes, which has the advantages of high energy conversion efficiency and can be coupled with high-temperature heat sources (such as high-temperature nuclear reactors, etc.). In the future, if it can solve the problem of high temperature Technical problems such as material stability and lifespan, as well as cost reduction, will have great application potential. It is still in the research and development and small-scale demonstration and application stages.
  Working principle: At high temperature, oxygen ions (O²⁻) in the solid oxide electrolyte migrate from the cathode to the anode under the action of the electric field. They react with the input water at the anode to generate oxygen, and at the cathode, oxygen is obtained from the external circuit. The hydrogen ions of electrons combine with oxygen ions to produce hydrogen gas.

Factors affecting the efficiency of hydrogen production from water electrolysis

• Electrode materials: Different electrode materials have different catalytic activities for electrolysis reactions. For example, noble metal electrodes often have better catalytic effects, can reduce the overpotential of the reaction, reduce power loss, and improve hydrogen production efficiency, but the cost is higher; while some transition New electrode materials such as metal compounds are also constantly being developed in order to achieve a better balance between cost and performance.
• Electrolyte concentration and properties: For alkaline electrolyzers, the appropriate electrolyte concentration affects the migration speed and conductivity of ions, etc., thus affecting the electrolysis efficiency; different types of electrolytes (such as KOH and NaOH) also have certain differences.
• Current density: Appropriately increasing the current density can speed up the electrolysis reaction and increase the production rate of hydrogen. However, too high a current density may lead to an increase in overpotential, an increase in power consumption, and may also affect the service life of electrodes and other materials, so it needs to be reasonable. control.
• Temperature: Generally speaking, an appropriate increase in temperature can speed up the reaction rate and reduce the electrical energy required for the reaction. However, the degree of impact and the appropriate temperature range are different for different types of electrolyzers. For example, solid oxide electrolyzers need to be at a higher temperature. Its advantages can only be exerted when it is operated at high temperature, while alkaline electrolyzers and PEM electrolyzers can operate at room temperature or within a certain medium temperature range.

Application areas

• Energy field: As a clean energy source, hydrogen can be used in fuel cell vehicles. It reacts with oxygen in the fuel cell to generate electric energy to drive the vehicle to achieve zero-emission transportation. It can also be used as an energy storage medium in renewable energy sources (such as wind energy and solar energy). When there is excess power generation, electrolysis of water is used to produce hydrogen to store energy. When energy demand peaks or renewable energy generation is insufficient, hydrogen is converted into electrical energy through fuel cells to replenish the power grid, which plays a role in peak shaving and valley filling, and stabilizing energy supply. .
• Chemical industry: Hydrogen is an important raw material in many chemical production processes. For example, it is used in the production of synthetic ammonia, which is produced by reacting with nitrogen. It can also be used in hydrocracking, hydrorefining and other processes in petroleum refining to improve oil products. quality, increase light oil yield, etc.

At present, water electrolysis hydrogen production technology is constantly developing and improving, and the cost is gradually reducing. Especially with the large-scale development of renewable energy, there are more and more electrolysis water hydrogen production projects coupled with it. In many countries around the world They are actively arranging related industries and promoting the development of green hydrogen production to help achieve goals such as energy transformation and addressing climate change. However, we still face many challenges such as further reduction of costs, improvement of performance and extension of life of key equipment such as electrolyzers. In the future, it is expected to be better solved through technological innovation and scale effect, and it will play a more important role in the construction of clean energy system.

Hydrogen production by electrolysis of water is the most advantageous method for producing hydrogen. Utrasonic coating systems are ideal for spraying carbon-based catalyst inks onto electrolyte membranes used for hydrogen generation. This technology can improve the stability and conversion efficiency of the diaphragm in the electrolytic water hydrogen production device. Cheersonic has extensive expertise coating proton exchange membrane electrolyzers, creating uniform, effective coatings possible for electrolysis applications.

Cheersonic ultrasonic coating systems are used in a number of electrolysis coating applications. The high uniformity of catalyst layers and even dispersion of suspended particles results in very high efficiency electrolyzer coatings, either single or double sided.

About Cheersonic

Cheersonic is the leading developer and manufacturer of ultrasonic coating systems for applying precise, thin film coatings to protect, strengthen or smooth surfaces on parts and components for the microelectronics/electronics, alternative energy, medical and industrial markets, including specialized glass applications in construction and automotive.

Our coating solutions are environmentally-friendly, efficient and highly reliable, and enable dramatic reductions in overspray, savings in raw material, water and energy usage and provide improved process repeatability, transfer efficiency, high uniformity and reduced emissions.

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