10 basic steps that any Atex Engineer should do in a Hydrogen (H2) Plant

Hydrogen has significant potential as a renewable energy source due to several factors. But Engineers designing a plant also face several challenges.

Given hydrogen's extreme combustibility, even small sparks, hot surfaces, or other ignition sources can trigger explosions in mixtures containing between 4% and 77% hydrogen by volume. Due to its profound hazard potential, hydrogen falls into ignition group IIC, alongside the most explosive gases. Consequently, stringent standards for the design and operation of hydrogen generation facilities are imperative.

Hydrogen necessitates a meticulously controlled environment, where only equipment devoid of ignition potential or equipped with suitable ATEX measures may be utilized within Ex Zones, both within facilities and their immediate vicinity.

One of the common concerns for Engineers in the Renewable energy sector is therefore how they should successfully ensure the safety of their plant and implement Ex d equipment ensure the safety of personnel and the facility. Here are some basic steps that any Renewable Energy Engineer should follow:

1. Understand ATEX Regulations: Familiarize yourself with the ATEX directives and regulations relevant to your jurisdiction. Ensure compliance with ATEX standards such as ATEX Directive 2014/34/EU for equipment and protective systems intended for use in potentially explosive atmospheres.
2. Conduct Hazardous Area Classification: Perform a thorough hazardous area classification of the hydrogen plant to identify zones where explosive atmospheres may occur. Classify areas into Zone 0, Zone 1, or Zone 2 depending on the likelihood and duration of the presence of explosive atmospheres.
3. Select ATEX-Certified Equipment: Choose ATEX-certified equipment suitable for use in hydrogen-rich environments. Ensure that all electrical and mechanical equipment installed in hazardous zones, such as pumps, motors, sensors, and lighting fixtures, are certified for the appropriate ATEX zone classification.
4. Implement Intrinsic Safety Measures: Opt for intrinsically safe equipment and instrumentation wherever possible. Intrinsically safe devices are designed to prevent the release of sufficient electrical or thermal energy to ignite a hazardous atmosphere, reducing the risk of explosion. In Plants where Hydrogen is permanent in the atmosphere, regulations may put severe restrictions on what type of atex equipment can be used. Generally, it may be that IS (Intrinsically safe) solutions are the only viable solution to ensure maximal safety.
5. Provide Proper Ventilation: Ensure adequate ventilation in enclosed areas to prevent the buildup of hydrogen gas concentrations beyond safe limits. Implement ventilation systems equipped with explosion-proof fans and dampers to maintain airflow and mitigate the risk of explosion.
6. Implement Explosion Protection Measures: Employ explosion protection measures such as explosion-proof enclosures, flame arrestors, and explosion isolation systems to contain and mitigate the effects of a potential explosion. Install explosion suppression systems and inert gas purging systems where necessary to prevent the ignition of flammable gases.
7. Train Personnel: Provide comprehensive training to personnel on the safe handling, operation, and maintenance of ATEX equipment. Educate employees on the risks associated with hydrogen and the importance of adhering to safety protocols and procedures.
8. Perform Regular Inspections and Maintenance: Establish a rigorous inspection and maintenance schedule for ATEX equipment to ensure continued compliance and optimal performance. Conduct periodic inspections, testing, and calibration of safety-critical devices to detect and address any issues promptly.
9. Implement Emergency Response Procedures: Develop and implement emergency response procedures for dealing with incidents involving the release or ignition of hydrogen gas. Train personnel in emergency evacuation protocols, firefighting techniques, and the use of personal protective equipment (PPE).
10. Engage Qualified Professionals: Seek the expertise of qualified engineers, safety consultants, and ATEX specialists to assist in the design, installation, and maintenance of ATEX-compliant systems and equipment. Ensure that all modifications and upgrades to the hydrogen plant are performed by competent professionals following industry best practices.

Materials:

Where H2 comes into contact with a material in a Valve, Switch or Transmitter for example (under roughly 65 bar of pressure) Stainless Steel 316 would be highly advised.

Why?

Hydrogen Embrittlement Resistance: Hydrogen embrittlement is a phenomenon where hydrogen atoms penetrate the crystal lattice of metals, causing them to become brittle and prone to fracture. Certain grades of stainless steel exhibit high resistance to hydrogen embrittlement, ensuring the mechanical integrity of hydrogen infrastructure.

Above 65 bar, Stainless 316 can actually in practice, become increasingly brittle in H2 Plants and thus would need to be reinforced with Gold Plating to increase the integrity of the metal. Gold has much smaller atomic holes than stainless steel, which means that the level of Hydrogen Embrittlement is significantly reduced to trace levels. Thus, the hydrogen can barely get through the gold layer.

Hardy's top tip:

For electrical safety devices in the surrounding plant however ceteris paribus, Stainless Steel may be an unnecessarily cost-ineffective solution. Something like a GRP Beacon, Sounder, or Sounder Beacon would provide a more economical solution to a Hydrogen Plant as there is minimal, if any exposure to Hydrogen in the surrounding environment whilst ensuring maximal safety of the AVS device.

GRP stands for Glass Reinforced Plastic, also known as fiberglass reinforced plastic (FRP) or simply fiberglass. It is a composite material made of a polymer matrix reinforced with glass fibers. GRP is commonly used in various industries for its excellent strength-to-weight ratio, corrosion resistance, and versatility.

In a Marine/Offshore environment however, where AVS (Audible and Visual Signalling) devices may be continually exposed to the saline in Seawater, SS 316 would provide the optimal longevity. The corrosion resistance between SS 316 and GRP is minimal, however it only takes a small crack from the corrosion of the salt with GRP to develop and render the device damaged.

At Ex-Tech Signalling we supply AVS devices globally. Whether it is a Hydrogen plant or a Marine application. A chemical, or Pharmaceutical application we have the technical expertise to save you money, time and ensure that your application is up to date with the appropriate Ex d directives.

Should you wish to discuss your ATEX requirements, Ex-Tech Signalling and Pyropress Ltd have over 70 years experience manufacturing a range of ATEX Switches, Transmittors and signalling equipment in Plymouth, UK.

Suitable for Zones 1 &2, 21 & 22 for a wide range of ATEX Applications, give us a call today and we would be happy to point you in direction of our global distributors. With free technical expertise of your process, what are you waiting for? Pick up the phone or send us an email today:

T: 01752 333939

E: [email protected]

W: https://www.pyropress.com

https://ex-techsignalling.com