Fluids Handling

Efficient electrolysis to optimise hydrogen production: Why valve and sensor technology are key

Burkert 32 minutes ago

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As the UK accelerates towards large-scale low-carbon hydrogen production, electrolysis processes are taking centre stage. This is placing increased emphasis on energy efficiency to optimise the viability and sustainability of hydrogen production. Valves and sensors designed specifically for the demands of electrolysis are vital for optimising efficiency and they also have a critical role in ensuring system safety.

Tony Brennan, Regional Business Development Manager for the energy sector at Bürkert, explains.

As the UK government forecasts the growth of low-carbon hydrogen production to around 5GW by 2030, this signals a multi-gigawatt expansion of electrolysis-based hydrogen production. This technique will also extend beyond green hydrogen as electrolysis is also playing a growing role in hybrid and industrial hydrogen systems as hydrogen supply chains decarbonise.

The UK has identified hydrogen as an important part of its pathway towards net zero with electrolytic hydrogen expected to play an increasingly significant role in future production. As electrolyser projects increase in scale, the ability to control the process accurately will become increasingly important for managing energy consumption, maintaining reliability and achieving consistent hydrogen production.

A key challenge for hydrogen producers is that electrolysis is energy intensive, requiring significant energy to break the strong and stable bonds in water molecules and drive the chemical reaction. As a result, optimising process efficiency is key to cost management and the system’s own sustainability rating.

For hydrogen producers, this means that efficiency cannot be considered solely at the electrolyser itself. Every stage of the process, from water supply and cooling through to pressure management and gas separation, can influence the overall performance of the system. Accurate measurement and precise control are therefore essential considerations when designing an efficient hydrogen production system.

Efficiency and reliability

Optimising efficiency depends on maintaining close control over flow and pressure where small deviations can reduce performance, increase electrical demand and cause system losses. As a result, precision valves and sensors are key across electrolysis techniques, including alkaline electrolysis (AEL), proton exchange membrane (PEMEL) electrolysis as well as solid oxide electrolysis (SOEL), which relies on steam rather than water as the source.

Although the technologies differ in their operating principles and process conditions, each requires accurate control of key parameters to maintain stable operation. Flow, pressure and temperature must be monitored and controlled closely to ensure that the electrolyser operates within its intended conditions.

Valves and sensors are also essential for maintaining safety and system reliability which is vital for maximised productivity and uptime. The stable management of pressure, temperature and gas separation is essential to prevent overpressure, backflow or unintended mixing of hydrogen and oxygen.

This makes process instrumentation an important part of the overall electrolyser system. Reliable sensors provide the data required for effective control while precision valves enable operators and control systems to respond to changes in operating conditions. Together, they help maintain process stability while supporting safe and efficient hydrogen production.

Cooling water, fresh water and recirculate

The initial stage in electrolysis involves the control of cooling water, fresh water and recirculate. Electromotive control valves provide automated control driven by an electric motor, offering greater precision and stability compared to pneumatic or hydraulic actuation.

A proportional valve can be set to any position within its range to enable precise control. A direct-acting valve that can achieve a defined opening, such as the Bürkert Type 3280, can hold a set position with zero current, making a significant energy saving.

This type of control can be particularly important in systems where energy consumption must be carefully managed. Since electrolysis already requires significant electrical input, reducing unnecessary energy consumption in supporting systems can contribute to improved overall process efficiency.

Continuous flow measurement of the supply is also important to optimise efficiency. Accurately measuring the deionised water supply ensures the electrolyser receives the optimum flow to prevent underfeeding which would reduce hydrogen yield or overfeeding which would waste pumping energy.

Maintaining the correct water supply is therefore an important part of achieving consistent electrolyser performance. Accurate flow measurement gives the control system the information required to maintain the desired operating conditions while avoiding unnecessary pumping energy.

Meanwhile, in cooling circuits, precise flow measurement allows operators to maintain stable stack temperature which affects overall energy consumption relative to the yield. Temperature control is particularly important because changes in stack operating conditions can influence the efficiency of the electrochemical reaction and therefore the relationship between energy consumption and hydrogen output.

A paddle wheel flowmeter suited for use with neutral, particle-free liquids can provide accurate continuous flow measurements in a compact in-line format. Bürkert’s Type 8030 provides the accuracy required, achieving +/-1% of the measured value with repeatability as close as +/-0.4%.

For hydrogen production systems, compact measurement technology can provide a practical way of monitoring essential process parameters without adding unnecessary complexity to the installation. Continuous flow measurement also supports more consistent operation by allowing deviations from the desired flow conditions to be identified and corrected.

Precise online analysis of the supply will also improve electrolyser efficiency as water quality, considering factors such as conductivity, pH and dissolved oxygen, directly affects reaction performance, component integrity and long-term system stability.

Water quality is particularly important in PEM systems where membrane health is highly sensitive to impurities. Monitoring the condition of the water supply can therefore help protect critical electrolyser components while supporting stable and reliable operation over time.

As hydrogen production systems move towards larger capacities, monitoring water quality alongside flow and pressure can become an increasingly important element of the overall process control strategy.

The electrolyser

Within the electrolyser itself, maintaining stable and balanced conditions on both half cells is essential. This includes the anode side where water is split to produce oxygen and the cathode side where hydrogen is formed from the resulting ions, or protons in the case of PEM systems.

The two sides of the electrolyser therefore perform different roles while operating as part of the same electrochemical process. Maintaining the correct balance between them is essential to achieving efficient and stable hydrogen production.

Any mismatch can reduce reaction efficiency, increase electrical losses and place stress on the separating membrane, potentially leading to gas crossover and reduced hydrogen purity.

Gas crossover is particularly important from a process safety and product quality perspective. Maintaining appropriate pressure conditions across the stack helps to minimise the potential for unwanted gas mixing while supporting the required hydrogen purity.

Demands on a valve system that can control both the anode and cathode sides of an electrolyser are high as each environment is hydraulically and chemically different and operates with different dynamics.

This is referred to as back pressure control as the valve regulates outlet resistance to set and stabilise the pressure within each half cell upstream of the valve.

Effective back pressure control is therefore a key part of maintaining the operating conditions required by the electrolyser. Precise control also allows the system to respond to changes in operating conditions rather than simply operating at a fixed pressure.

Bürkert’s Type 3361 electromotive control valve has been designed to precisely and dynamically control outlet pressure on both the anode and cathode sides.

Minimising pressure differentials and associated losses, the valve’s stable control ensures the electrolyser operates consistently at its optimal efficiency point even under transient load conditions.

This dynamic control capability is particularly relevant as hydrogen electrolysis becomes increasingly integrated with variable energy sources. As the wider hydrogen industry develops, the ability of electrolysers to operate efficiently under changing conditions will be an important consideration for system designers and operators.

Accurate pressure measurement

To measure the pressure of hydrogen leaving the stack via the cathode circuit as well as measuring the pressure of oxygen discharged from the stack via the anode circuit, an accurate sensor is vital.

Along with an accuracy requirement meeting levels around 0.1% deviation of the measured value, the need for reliability and durability at the stack outlets are also critical attributes of sensor design.

The pressure transmitter should be manufactured from corrosion-resistant stainless steel and a design including a flush diaphragm guarantees security when working with hydrogen.

Accurate pressure measurement provides the information required to maintain the correct conditions within the electrolyser and its associated circuits. It also supports the wider control strategy by helping operators identify changes in pressure that could affect efficiency, reliability or safety.

The demanding conditions around the electrolyser stack mean that sensor selection must consider more than measurement accuracy alone. Materials, durability and compatibility with hydrogen service are also important factors when specifying instrumentation for hydrogen production systems.

Safe shut-off

Above all, ensuring safety in an electrolysis system is critical. In particular, this surrounds the outlets of the electrolysis stack as well as downstream in gas separation, drying and purification units and also at the storage and compression interface.

The oxygen outlet from the anode side of the stack is a critical area too. Across each of these locations as well as other plant control points, shut-down valves are essential.

Reliable isolation is a fundamental requirement for hydrogen production because hydrogen and oxygen are generated as part of the same electrochemical process. Effective shut-off therefore forms an important part of the overall safety strategy, particularly during start-up, normal operation and emergency shutdown conditions.

The Bürkert Type 6240 solenoid valve is suited to hydrogen electrolysis systems as it provides fast reliable electrical shut-off of gas streams, ensuring safe isolation of hydrogen during start-up, operation and emergency shutdown conditions.

Its direct-acting design enables rapid response and tight sealing which is critical for preventing unwanted gas migration.

The ability to isolate gas streams quickly can support safe plant operation across multiple stages of the hydrogen production process. This includes the electrolyser outlets as well as downstream gas handling equipment where hydrogen is separated, dried and purified before being transferred to storage or compression.

In addition to its safety role, the valve can also support system efficiency by enabling “kick-and-drop” operation, where a brief high-energy actuation ‘kick’ ensures reliable switching followed by a lower holding energy state, reducing overall power consumption while maintaining a secure valve position.

This demonstrates how valve technology can contribute to both safety and energy efficiency. While the primary function of a shut-down valve is safe isolation, reducing the energy required to maintain the valve in its operating position can also help minimise the auxiliary energy demand of the wider system.

From development to scale

As electrolysis production of hydrogen scales from development through to large-scale yields, precision control will be increasingly relied on to ensure efficiency, safety and reliability at every stage.

The challenge for hydrogen producers is not simply to increase electrolyser capacity. Systems must also maintain stable operating conditions as they become larger and more complex. This places greater emphasis on accurate process measurement, reliable automation and control technologies that can respond quickly to changes in operating conditions.

Valve and sensor technology will not only optimise energy use and process stability but also help to facilitate faster system integration and commissioning, accelerating time to market for hydrogen projects.

For project developers and system integrators, the selection of suitable valves and sensors can therefore form an important part of the wider engineering strategy. Components designed around the specific requirements of hydrogen electrolysis can help simplify control while providing the measurement and isolation capabilities needed for safe operation.

By maintaining optimal operating conditions across both small-scale development units and gigawatt-scale installations, the most efficient and reliable valves and sensors will provide the foundation for hydrogen production at scale as the industry expands.

As the UK hydrogen sector develops, electrolysis will continue to require careful attention to energy consumption, process efficiency and system reliability. Precision flow measurement, pressure control, water quality monitoring and dependable shut-off all have a role to play in achieving these objectives.

Ultimately, efficient hydrogen electrolysis depends on the effective coordination of the entire process. By combining accurate sensors with responsive valve technology, operators can maintain the conditions required for efficient hydrogen production while supporting safety and reliability as systems move from development projects towards large-scale deployment.

For further information, contact;

Bürkert Fluid Control Systems
Tel.: +44 1285 64 87 20
sales.uk@burkert.com
www.burkert.com

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Burkert Fluid Control Systems

01285648720
sales.uk@burkert.com
http://www.burkert.com/
Fluid Control Centre 1 Bridge End Gloucestershire Cirencester GL7 1QY GB

About us

Bürkert is present in thirtyfive countries around the world. We also work with a large network of distributors and partners, which means we are as close as possible to our customers. This global presence ensures full service and support to all of our customers in every country around the world. Research is the lifeblood of our company.

At Bürkert, we are never satisfied with the status quo and are continually seeking new technologies and solutions for our customers. Every year, our people develop new and highly advanced products and solutions, ranging from integrated process measurement and control units to the most sophisticated systems used in pharmaceutical research. To be a market leader, we are also an R&D leader.

Therefore, our investment in research & development is one of the highest in our industry. In our research centres in Germany and France, 150 people are committed to working for a common future for our company and our customers. We are committed to offering our expertise wherever it is needed, anywhere in the world. This global presence ensures that our advances in fluid control technology are also global.

What we do in a nutshell

Manufacture of process equipment. One of the few manufacturers to provide solutions for the complete control loop.

Where we supply to

UK Ireland, Europe

Industries we supply to

Food and Beverage, Pharmaceutical Cosmetics Toiletries, Water and Wastewater

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