Hydrogen filling stations: Green mobility

Hydrogen is a flexible energy storage medium that, together with the volatile production of solar and wind energy, is a solution for reducing greenhouse gases. One of the challenges will be the generation of electricity for the electrolysis required to produce hydrogen.

Production and delivery of hydrogen

At hydrogen filling stations, the required hydrogen can either be produced directly on site through electrolysis or delivered.

Storage of hydrogen

Hydrogen is temporarily stored at the filling station either in gaseous or liquefied form.
When stored in gaseous form, special high-pressure tanks are used that reach pressures between 30 and 500 bar. It is particularly important to protect against these high pressures. The HEROSE safety valve type 06810 with a set pressure of up to 800 bar is up to the task.
When stored in liquefied form, temperatures of up to -255 °C are reached. The evaporation of hydrogen must be minimized to prevent losses. Our top-entry valve FullX type 11C01, optionally with vacuum insulation, is designed for this application.

Compression and buffer storage

To refuel the vehicle, the hydrogen pressure must be further increased and buffered. Pressures of over 1,000 bar are achieved in order to be able to refuel several vehicles in a short time. The safety valve type 06820 with a setting pressure of up to 1,200 bar has enough capacity to protect lines and buffer tanks.

Cooling and refuelling

Cooling on site is carried out by a heat exchanger that contains coolant. Cooling is necessary to prevent overheating when refuelling, because heat is generated during the process due to the compression of the hydrogen in the vehicle tank.

To refuel, the vehicle's tank nozzle is connected to the filling station via the pump tap. The hydrogen is pumped into the vehicle tank at high pressure. The hydrogen is often cooled down to -40 °C beforehand. The refuelling normally only takes 3-5 minutes for cars and 10-15 minutes for trucks, so this step can be carried out quickly.

On the vehicle side, the hydrogen is also stored in special tanks under high pressure of 700 bar. The stored hydrogen is converted into electrical energy in a fuel cell. This energy then drives the electric motor.

Since the vehicle usually does not have a safety valve to release excessive pressure, the filling station must ensure that the pressure in the vehicle never gets too high. For this purpose, the pump is equipped with a safety valve that releases hydrogen if the pressure is too high. Here, too, the valves type 06810 are used for 350 bar refuelling and type 06820 for 700 bar refuelling.