Hydrogen and safety solutions for electrical hazards in explosive environments
The quest for net-zero emissions and global decarbonization has driven a dramatic increase in demand for renewable energy sources. Hydrogen is rapidly emerging as a promising solution, especially for its dual role as both a source of and storage medium for energy.
As governments and industries aim to meet aggressive decarbonization goals by 2030, hydrogen production, distribution, and storage facilities are expanding worldwide. But with this rise in hydrogen usage comes an important challenge: safety. Hydrogen, while a clean and efficient energy carrier, is also highly explosive, requiring robust protective measures in hazardous environments.
Planned and operational water electrolysis projects in Europe
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The promise of green hydrogen and the need for transition
Hydrogen comes in various "colors", each representing a different production method, and consequently, a different environmental impact. The hydrogen color spectrum includes black, grey, blue, and green hydrogen, with green hydrogen being the most environmentally friendly.
Colors of hydrogen
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Today, the majority of the world’s hydrogen is produced through steam methane reforming, a process with natural gas containing methane CH4 being split into hydrogen H2 and CO2
Steam-methane reforming reaction
CH4 + H2O (+ heat) → CO + 3H2
Water-gas shift reaction
CO + H2O → CO2 + H2 (+ small amount of heat)
which emits significant amounts of carbon dioxide (CO2) as a by-product of the process itself and as a by-product of heating the steam reformer to 800-900 degC.
This form of hydrogen, often referred to as black or grey hydrogen, must be replaced if the global net-zero carbon goal is to be achieved.
Green hydrogen, on the other hand, is produced via electrolysis, where electric power—preferably generated by renewable sources - is used to split water (H2O) into hydrogen (H2) and oxygen (O2). Despite the clear environmental benefits, only about 5% of hydrogen production today is green. Scaling up green hydrogen production is essential to realizing a low-carbon economy, as it provides a sustainable pathway for industries heavily reliant on fossil fuels to transition toward cleaner energy solutions.
Hydrogen’s explosive nature: An ongoing safety challenge
While hydrogen has many advantages, its highly explosive nature poses a significant risk. The ignition energy required for hydrogen is much lower compared to other traditional gases, such as liquefied natural gas (LNG), and its ignitable hydrogen/oxygen mixture range is much broader. This means that the risk of explosion is inherently higher wherever hydrogen is produced, stored, or used.
In environments where hydrogen is handled, hazardous areas - where the possibility of an explosion exists - are automatically created. This necessitates a comprehensive safety framework to prevent potential hazards. Hydrogen-related safety measures extend across the entire value chain, from production facilities to transportation pipelines, and down to storage tanks and end-user applications.
As the world plans for significant expansion in hydrogen infrastructure, it is crucial that safety considerations evolve alongside the growth. This expansion introduces safety dimensions, particularly related to electrical hazards in explosive environments, which must be addressed to enable the widespread use of hydrogen as a safe and effective energy solution.
Managing electrical hazards in explosive hydrogen environments
One of the most critical aspects of safety in hydrogen-rich environments is managing electrical hazards. Even small sparks from electrical components can ignite hydrogen, which is why companies working in this space must adopt stringent safety protocols and technologies.
In hazardous environments, explosion-proof equipment is vital to prevent the ignition of hydrogen. Electrical systems used in hydrogen processing, storage, and transport must adhere to specific safety standards that minimize the risk of sparks or other ignition sources. This involves the use of intrinsic safety (IS) equipment, designed to operate safely in explosive atmospheres by limiting the electrical and thermal energy available for ignition.
For example, using intrinsically safe devices in hydrogen environments ensures that the energy from the electrical equipment is not sufficient to trigger a hydrogen explosion. The intrinsic safety design principle is particularly crucial for measuring and controlling process values like pressure, temperature, and flow in hydrogen production and distribution processes.
PR electronics: A trusted partner for hydrogen safety solutions
In the complex and high-stakes environments where hydrogen is handled, PR electronics offers advanced solutions for interfacing process values, especially in explosive hydrogen environments. With over 50 years of experience, PR electronics specializes in developing cost-effective solutions for instrumentation in hazardous zones, including those involving hydrogen. Our expertise in explosion-proof instrumentation allows for seamless integration of sensors and control systems, ensuring safety while optimizing process efficiency.
PR electronics focuses on providing instrumentation that meets the strict requirements of explosive environments and their associated Ex standards as ATEX, IECEx, UL, FM etc. The range of intrinsically safe devices enables the accurate and safe monitoring of hydrogen-related processes, and their associated signals related to e.g. temperature, pressure, level, and flow from production to storage and transport. This ensures that critical process values like pressure, flow, valve status and temperature are measured reliably, even in the most challenging conditions.
As hydrogen’s role in the global energy mix continues to grow, so does the need for trusted partners who understand the unique safety challenges that hydrogen presents. PR electronics is a leader in this space, offering innovative solutions that help industries navigate the complexities of working with explosive gases like hydrogen.
Intrinsically safe solutions for hazardous zones
PR electronics provides a range of intrinsically safe (IS) solutions, designed for environments exposed to hydrogen. Easy to engineer and maintain, these solutions ensure reliable performance in areas with varying zone classifications, such as Zone 0 / Div 1, where explosive hydrogen gas is continuously present. Hydrogen, classified as Gas Group IIC, requires special care since even minimal sparks can ignite it. PR electronics ensures safe interfacing of instruments like temperature sensors and pressure transmitters in such hazardous zones.
Zone classifications and compliance
PR electronics’ products comply with EN / IEC 60079 standards, ensuring safety in hydrogen environments. Solutions are tailored for different classifications:
- Zone 0 / Div 1: Continuous presence of hydrogen gas.
- Zone 1 / Div 1: Occasional presence of hydrogen gas.
- Zone 2 / Div 2: Lower risk of hydrogen presence, but safety measures still apply.
Temperature classifications for hydrogen equipment
Hydrogen has an auto-ignition temperature of 560°C.
An IS product with the T4-T6 temperature rating (T1 least stringent) is sufficient to avoid any hazard related to ambient temperature, but due to its low ignition energy, equipment must be designed and monitored carefully. PR electronics provides temperature-rated solutions that maintain safety even under demanding conditions.
Solution example for monitoring temperature
Simple steps to qualify your intrinsic safety system (ATEX environment)
- Transmitter in Zone 0 Exia rated / Barrier in safe area [Ex ia] rated.
- Hydrogen requires a Gas Group IIC rated product.
- Determine the Zone / Division area classification for the transmitter – in this case, Zone 0 / DIV 1 for continuous presence of hydrogen.
- Determine the operating temperatures for the transmitter – e.g., 80°C ambient. Hydrogen's ignition temperature of 560°C is well above the temperature requirement for Ex temperature classification T4 = 135°C. The barrier has an ambient operating temperature of up to 60°C in the safe area.
- Perform a loop calculation for the complete IS system, including the transmitter, cable, and barrier, with the respective entity parameters
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PR 5337D Temperature transmitter PR 5337D with an ATEX Ex rating: II 1 G Ex ia IIC T6...T4 Ga |
PR 9106B Barrier PR 9106B for safe area installation with ATEX Ex rating: II (1) G [Ex ia Ga] IIC/IIB/IIA |
For simplicity only ATEX ratings are listed here. Similar product ratings will be observed for IECEx, UL, FM, INMETRO etc. Please consult the product manual / datasheet.
Working with PR electronics IS solutions
PR electronics offers easy-to-use, intrinsically safe devices that simplify safety in hydrogen environments. Designed for user-friendliness, our solutions help companies focus on optimizing processes while minimizing safety risks in hazardous zones.
Advantages of intrinsic safety
Intrinsic safety offers several advantages:
- Simplified maintenance with live work possible.
- Lower costs compared to explosion-proof enclosures and associated components.
- Fault-tolerant designs.
- Applicability to all gas and dust zones.
