Hydrogen through natural gas pipelines: safe and sustainable

Hydrogen can be safely transported through natural gas pipelines. Gasunie is an expert in the transport of natural gas and has years of experience in transporting hydrogen through a gas pipeline in the Dutch province of Zeeland. By using the existing natural gas network and installing new pipelines where necessary, a robust national transport network for hydrogen can be created.

Read the in-depth interview with experts Martin van Agteren and Otto Jan Huisingees on repurposing natural gas pipelines to build the hydrogen network.

Over the coming years, the Netherlands will see a decrease in the transport of natural gas. This is due to the phasing out of gas extraction in Groningen on the one hand and, on the other, because the Netherlands is using its energy sources ever more efficiently while also increasing sustainability through the use of alternative energy carriers. Now that the transport of natural gas is on a downward path, part of the gas network is becoming available for the transport of hydrogen.

The safety risks of transporting hydrogen through gas pipelines are comparable to those of natural gas. When transporting hydrogen, the effect of hydrogen on the pipeline and the higher ignition probability when clearing a pipeline of gas to make changes to the pipeline are taken into account.

Hydrogen and embrittlement

Hydrogen atoms can cause existing crack-like defects in welded joints to grow faster under pressure variations than natural gas. This is a form of hydrogen embrittlement. The likelihood of such defects is very low. This is because the pipelines have been thoroughly examined both at the plant and in the field, under the oversight of an independent inspection. For safety reasons, Gasunie also monitors pressure fluctuations to confirm that they cannot lead to a leak.

Ventilation prevents hydrogen accumulation

Hydrogen molecules are lighter than methane molecules (methane is the main component of natural gas) so it rises faster. This is a positive quality in case of leaks. The risk of a flammable or explosive mixture is lower than with natural gas. However, the ignition energy is much lower with a flammable hydrogen-air mixture.

Ventilation is important because hydrogen, like natural gas, can accumulate in confined spaces. This can lead to fire or explosions. Needless to say, Gasunie ensures that leaks with hydrogen occur as little as possible, just as with natural gas. For example, by not blowing off hydrogen but burning it, releasing only water.

Preventing leaks is better for the climate

Hydrogen itself has no direct effect on global warming because the hydrogen molecule cannot absorb infrared radiation. The methane molecule can absorb infrared radiation, which is why it is called a greenhouse gas. In theory, hydrogen can slow down the breakdown of methane in the atmosphere, causing the methane to stay in the atmosphere longer and retain heat longer. We obviously want to avoid that effect. To keep hydrogen emissions as low as possible, Gasunie takes this into account when designing and maintaining the hydrogen network.