Hydrogen

For many years, hydrogen technologies have been an integral part of the process industry, especially in areas such as refineries, methanol, and ammonia production, where natural gas and coal primarily serve as the base materials for hydrogen production. With the increasing focus on a low-carbon future, the generation of hydrogen from renewable sources, for example through electrolysis using electricity from solar and wind energy, is gaining importance. This “green” hydrogen production is crucial for the desired decarbonization of the global economy and promises to play a key role in the energy supply of the future.

Throughout the hydrogen value chain – from generation through processing and distribution to storage – the equipment and materials used must meet extreme requirements. They are exposed to temperatures up to -253 °C, pressures up to 700 bar and beyond, as well as specific challenges such as hydrogen migration, which can cause material fatigue and cracking in metals. In addition, handling hydrogen requires special safety measures and materials that can withstand diffusion and the reactive properties of hydrogen. Therefore, the development and implementation of technologies for the safe and efficient handling of hydrogen are crucial for the successful integration of hydrogen as an energy carrier in a wide range of industrial applications.

Hydrogen-induced embrittlement – Continuous exposure to hydrogen can lead to the phenomenon of hydrogen-induced embrittlement in certain materials. In this process, hydrogen penetrates the microstructure of materials, causing a reduction in mechanical strength and ultimately structural failure. To prevent such negative effects, the selection of materials that come into direct contact with hydrogen is of crucial importance. Typically, the use of austenitic steels such as 316L or 316Ti is recommended. In addition, specialized alloys such as Hastelloy C276, Inconel 718, or 2.4711 (Elgiloy®) offer high resistance against hydrogen embrittlement. Beyond material selection, it is important to follow specific guidelines and best practices in the design and maintenance of hydrogen applications to ensure the integrity and longevity of the components used.
Hydrogen permeation – Hydrogen, the lightest element in the periodic table, consists of the second smallest atoms after helium. When in contact with metal surfaces, hydrogen molecules require only a small amount of energy to be split into individual atoms and eventually converted into protons (H+-ions). These protons can then penetrate metal and alloy structures, leading over time to changes in the signal of the measuring sensor. The degree of this effect increases with the energy introduced into the process by higher temperatures or pressures. To minimize the penetration of hydrogen through metal and thus a change in sensor signal, a gold coating provides an effective solution. Gold forms an efficient barrier against hydrogen permeation, with a significantly lower permeation rate compared to common industrial materials such as stainless steel 316L. This protective layer helps ensure the long-term stability and accuracy of sensors in hydrogen-rich environments by significantly reducing the interaction between hydrogen ions and the interior of the sensor. Thus, the reliability and lifespan of measuring instruments in demanding applications, especially at high temperatures and pressures, can be significantly improved.
Leaks in hydrogen systems – Hydrogen can form explosive mixtures with air at concentrations as low as 4 mole percent in the air. Therefore, it is critical to avoid or greatly limit leaks in systems that work with hydrogen. An effective ventilation system is essential for the safe operation of hydrogen applications to minimize potential risks. For this reason, metallic seals are often chosen in hydrogen environments, as they offer higher tightness and resistance to the specific properties of hydrogen. Moreover, it is important that the leak rate within the measuring components is kept as low as possible to further increase safety and effectively prevent the unintended release of hydrogen. Modern measuring devices and systems are therefore designed to meet the specific requirements of hydrogen applications, including the use of materials and technologies that minimize leakage rates.
Challenges in hydrogen storage – Storing hydrogen poses various challenges in measurement and handling depending on its state of aggregation. In gaseous form, hydrogen is stored at pressures up to 700 bar, requiring the use of pressure sensors that allow measurements up to 1,050 bar to accommodate temperature fluctuations and safety requirements. This is particularly important for use at hydrogen refueling stations. In its liquid form, hydrogen is kept at extremely low temperatures of -253 °C or below. Therefore, solutions for temperature monitoring must not only be capable of precisely measuring these extreme conditions but also not impair the effectiveness of tank insulation. Additionally, the materials and technologies used must be able to withstand harsh environmental conditions without losing accuracy or reliability. It is crucial that the measuring instruments are robust enough to ensure long-term stability and functionality under these extreme conditions, which is a key prerequisite for the safe and efficient use of hydrogen as an energy source.

➜ Hydrogen Production

Electrolysis

The production of green hydrogen, a key component of the energy transition, typically starts with the process of water electrolysis. In this technology, water molecules (H2O) are split into hydrogen (H2) and oxygen (O2) by the use of electricity derived from renewable sources such as solar energy, wind power, or hydropower.

Currently, three main types of electrolysis processes dominate the market:

Alkaline electrolyzers use an aqueous solution of potassium hydroxide as the electrolyte to catalyze the splitting of water molecules.
Proton exchange membrane electrolyzers (PEM) use a special polymer electrolyte membrane that allows for high efficiency in hydrogen production.
“Solid Oxide Electrolyser Cell” technology (SOEC) relies on the electrochemical decomposition of steam into its components at high temperatures of up to 850 °C.

Each of these electrolysis techniques poses specific operational requirements, especially in terms of process pressure, temperature, and the medium used. To master these challenges, we offer a comprehensive range of measurement solutions for pressure, temperature, flow, and level. These instruments are crucial for the efficient and safe operation of the electrolyzers and thus contribute to the optimization of hydrogen production. In addition, they support the maintenance and monitoring of the facilities to ensure their longevity and reliability, which in turn contributes to cost efficiency and strengthens the green hydrogen economy.

Products - Electrolysis

WIKA Models IV30, IV31, IV50, IV51 Valve manifold 3-, 5-valve manifold for differential pressure measuring instruments

Low-wear design due to non-rotating spindle tip in the bonnet
Low torque and smooth operation of valve handle even at high pressure
Enhanced safety due to blow-out proof bonnet design
Customer-specific combination of valves and instruments (hook-up) on request
Standardised centre distances of 37 mm and 54 mm, suitable for WIKA differential pressure gauges and commonly used process transmitters

Datasheet
User Manual

Hydrogen

➜ Hydrogen Production

Electrolysis

Conventional H2 Production

➜ Hydrogen Storage and Transport

Storage and Transport

Compression

Hydrogen Fuel Stations

➜ Use of Hydrogen

Stationary Fuel Cells

Mobile Fuel Cells

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Conventional H₂ Production