Hydrogen is an increasingly important player, especially since renewable energies are gaining ground in industry. However, it is essential to consider the electrostatic risks associated with its use.
The main risks associated with hydrogen in an industrial environment
Formation of an explosive atmosphere
Hydrogen is a very light gas and can mix easily with air. When released, it can form explosive mixtures with air, especially in environments where ignition sources, such as sparks, may be present. Static electricity is a potential source of ignition for these explosive mixtures.
Accumulation of static loads
Equipment that handles or transports hydrogen can accumulate electrostatic charges. For example, pipes, tanks and transfer equipment can become charged due to the movement of hydrogen or the building materials themselves. These charges can discharge suddenly, creating sparks that can trigger an explosion if the gas is present in sufficient concentration.
Electrostatic discharge (ESD)
Electrostatic discharges can cause sparks in environments where hydrogen is present. Even a low-intensity discharge can be sufficient to ignite a mixture of hydrogen and air, particularly in confined or poorly ventilated environments.
Propagation of static loads
Hydrogen, because of its low mass, can easily move and diffuse in the air. If installations or systems for transporting hydrogen are not properly designed to prevent the build-up of charges, these charges can propagate through conductive surfaces or equipment, increasing the risk of ignition.
What are the sources of electrostatic charge?
To understand the electrostatic risks associated with hydrogen, it is essential to identify the sources of electrostatic charge. These charges can be generated by a variety of mechanisms. Here are some common sources of electrostatic charge:
- Friction between two different materials, as when hydrogen moves in pipes.
- Contact and separation of surfaces, e.g. when containers are filled or emptied.
- Electrostatic induction caused by external electric fields near storage equipment.
Avoid electrostatic hazards by taking preventive measures. Make sure equipment is properly grounded, and use antistatic materials where possible. Regular monitoring of installations is recommended.
What are antistatic materials?
To reduce the electrostatic risks associated with hydrogen, use antistatic materials. These materials disperse electrical charges, preventing the build-up of dangerous charges. They are often used in environments where hydrogen is handled or stored.
We also recommend regular checks on the condition of these materials. Wear and tear can reduce their effectiveness. Incorporating this check into your maintenance routines reduces electrostatic risks and ensures a safer environment for all.
Install earthing systems
To reduce the electrostatic risks associated with hydrogen, grounding systems are essential. These systems dissipate accumulated electrical charges, reducing the likelihood of a dangerous electrostatic discharge.
Here are a few ways to set up these systems:
- Use conductive materials for tanks and piping.
- Install ATEX grounding cables and grounding reels on all equipment.
- Ensure that work surfaces are earthed.
- Regularly check the electrical continuity of ground connections.
Caution: Regular maintenance of grounding systems is essential to ensure their effectiveness. Periodic inspections minimize electrostatic risks by ensuring that all connections are intact and functional.
Monitor and control environmental humidity
Adequate humidity reduces the build-up of electrostatic charges. Use hygrometers to regularly measure relative humidity in sensitive areas.
Keep relative humidity between 40% and 60%. This helps dissipate electrostatic charges more effectively. Humidity control systems such as humidifiers and dehumidifiers can help maintain this optimum range.
Here are a few things you can do:
- Install hygrometers in critical areas.
- Use humidifiers to increase humidity if necessary.
- Use dehumidifiers to reduce excessive humidity.
- Monitor humidity levels regularly and adjust systems accordingly.
Good humidity control minimizes electrostatic risks and contributes to a safer environment for handling hydrogen. Adopt these practices for effective prevention.
In short, taking into account the electrostatic risks associated with hydrogen is essential to ensure the safety of installations and personnel. A thorough understanding and the implementation of adequate preventive measures are essential to minimize these risks and ensure safe handling of this potentially hazardous gas.
