Top Safety Considerations for Hydrogen Plant System Development Near Edmonton

Alberta is on its way to becoming a major hydrogen hub. As the industry grows and new hydrogen plants and pipelines are constructed, it will become increasingly important for hydrogen producers to ensure they are designed with safety as the number one priority.

Hydrogen production is very different from other fuel production and refining processes, and an understanding of the safety issues in hydrogen plant development is essential. In this post, we’ll look at the key safety considerations in hydrogen plant development, including the smaller, often overlooked components and systems critical to plant safety and the value of seeking expert advice on the safest, most reliable systems.

Hydrogen Safety Hazards

Ensuring safety in hydrogen plant development requires an understanding of hydrogen’s properties to minimize its hazards.

Hydrogen gas is colourless, odourless, tasteless, and generally undetectable by human senses. It’s also non-toxic and non-poisonous, so hydrogen gas doesn’t cause any direct harm to humans. However, its difficulty to detect means that major leaks can go unnoticed. Leaks won’t release anything toxic, but they can create other safety hazards under certain conditions.

Hydrogen Gas Is Highly Flammable

Hydrogen has a very low ignition energy and is combustible over a wide range of concentrations. At atmospheric pressure, hydrogen is combustible at concentrations from 4% to 74.2%. This means it only takes a small spark to ignite a small amount of hydrogen in the air.

Hydrogen fires can be just as difficult to detect as a leak. The flame is nearly invisible and produces no smoke, and it emits little radiant heat, so you may not see or even feel the heat from a hydrogen fire unless you are very close to it. This makes sensors such as thermal imaging cameras essential for fire monitoring.

Hydrogen Is Lighter Than Air

Hydrogen is the lightest molecule in existence, so when it leaks, it rises quickly. Outdoors, it dissipates quickly, reducing the risk of fire. Indoors, however, leaking hydrogen rises to the ceiling where it tends to accumulate in pockets. While this means workers on the ground won’t be exposed to the flammable gas, it can still cause fires or explosions, and again, it’s easy to overlook these pockets of invisible gas. Proper ventilation design in hydrogen plant development is essential to prevent this hazard.

Hydrogen Plant Design Considerations

Preventing fire and explosion hazards requires careful planning and plant design. Even the smallest components should be selected carefully and with safe hydrogen service in mind. To reduce the risk of the hazards described above, consider these hydrogen plant development tips:

Use Leak-Resistant Components

Hydrogen loves to leak because it is such a tiny molecule. To limit potential leak points, piping and tubing systems should be designed with as few joints as possible and all components must be rated for hydrogen service and the specific operating conditions of the process. 

Fittings must be mechanically sound and capable of sealing hydrogen. Welded tube fittings are preferred over mechanical fittings as they create a more effective seal. Threaded connections should be avoided to eliminate potential leak paths. Regardless of type, all fittings must be made of hydrogen-compatible materials and engineered for the pressure and temperature conditions under which they will be used.

Swagelok FK-series tube fittings are specifically engineered for the unique demands of hydrogen service, with 316 stainless steel fabrication and pressure ratings up to 22,500 psi. Swagelok SWS welding system allow gas-sealing welded connections that are also a good option for sealing hydrogen piping.

Hoses are vulnerable to abuse and damage and should be protected with a flexible covering that provides resistance to abrasion and fire. Hoses may be metallic or nonmetallic but must be made of a conductive material so they can be grounded. They should be inspected at least annually and replaced as soon as they show any wear or damage or no less frequently than every three years.

Process Hydrogen Outdoors or in a Well-Ventilated Area

To minimize the risk of hydrogen leaks and potential fires inside the plant, hydrogen plants should be set up so gas is supplied from an outdoor area at a safe distance from structures, ventilation intakes, and vehicle routes. If hydrogen must be used indoors, it should be stored outdoors before use and supplied to the indoor area with hydrogen-rated, welded piping.

Indoors, passive ventilation features such as roof or eave vents can prevent leaking hydrogen from accumulating near the ceiling. The plant’s ceiling and roof should be designed to ensure hydrogen can dissipate safely. Inlets should be located at the floor level, while outlets should be located at the high point of the room.

Active ventilation systems can be used to ensure sufficient airflow to keep hydrogen concentration below the flammability limit. However, keep in mind that no active ventilation system can effectively disperse the kind of massive hydrogen leak released from a pressurized vessel, pipe rupture, or blowdown.

When hydrogen is stored inside, make sure to incorporate measures during hydrogen plant development to minimize risks. For example:

• Limit the total hydrogen volume based on workspace size.
• Store hydrogen cylinders away from cylinders containing oxidants.
• Keep cylinders secured.
• Use only non-combustible materials for plant infrastructure.
• Set up ventilation systems to introduce airflow to the floor and exhaust at the highest point of the room.
• Install hydrogen sensors throughout the plant.
• Install dispensers in unconfined areas with ceiling heights of at least 7.5 meters.

Design for Fire Safety

It is critical to ensure that if a hydrogen leak or fire occurs, it is detected quickly and personnel are notified. Flame and leak detectors are required because hydrogen gas is colorless and odorless and the flames can be difficult to see.

Any areas where hydrogen is dispensed or stored must have fire alarms, portable fire extinguishers, and a manual emergency stop button located remotely from but within sight of the dispenser. The emergency stop should end the process and isolate the hydrogen outside of the facility. Sprinklers can be installed to prevent fire damage, but water should not be sprayed on hydrogen flames. Only personnel trained in hydrogen firefighting should attempt to control a hydrogen fire.

Install Safe and Reliable Grab Sampling Systems

Hydrogen production requires regular sampling and analysis to ensure purity. If the samples are not representative, though, problems can go undetected. This can not only compromise product purity but also potentially create safety hazards.

Fortunately, there are grab sampling system components designed specifically for hydrogen sampling. Two options to consider are quick-connects and purge bypass tubes.

Stainless steel quick-connects allow sample cylinders to be safely and easily attached and detached from sampling stations. Quick-connects can easily handle high-pressure hydrogen sampling and offer unrestricted flow for gas transfers. They can also be keyed to prevent accidental intermixing of different lines in multi-pressure or multi-fluid systems.

Purging helps ensure representative hydrogen samples by clearing the sample line of any residue from previous samples. A purge bypass tube circulates an inert gas, typically nitrogen, through the sampling system to remove any residual gas or contaminants before and after drawing a sample. The inert gas and any residual gases are then vented.

An Experienced Local Vendor Can Help with Safe Hydrogen Plant Development

At Edmonton Valve & Fitting, we understand that the growth of the hydrogen industry is exciting but also requires a focus on safety during hydrogen plant development. Fortunately, we have the experience and expertise with hydrogen service to help you make the right decisions. 

We offer a wide range of hydrogen-compatible Swagelok components with top-quality metallurgy, leak-tight designs, and high-pressure resistance. We also offer components suitable for on-vehicle applications, including light-duty, heavy-duty, rail, ship, and aerospace.

Our Field Advisors can perform an onsite consultation to assess your hydrogen plant development needs and recommend the best systems and components to ensure safe, reliable operations. Field Advisory services include, but are not limited to:

•     Virtual onsite evaluations
•     Design advice
•     Leak detection and repair
•     Product-specific training
•     Component and instrumentation advice
•     Regulator sizing guidance