Making ‘Groningen’ gas using the Zuidbroek nitrogen installation

In the Netherlands, we are used to using natural gas with a certain composition. How do we get the same quality gas after the Groningen gas field has closed? The nitrogen installation near Zuidbroek is a pivotal piece of this puzzle. Gas extraction from the Groningen field will then no longer be necessary.

Natural gas is composed mainly of methane and nitrogen, but the ratio is not the same in all natural gas. Gas from the Groningen field has an exceptionally high nitrogen content: 14 percent. Traditionally, all gas-powered equipment in the Netherlands has been designed with relatively low methane content in mind. This is now becoming an issue as more and more foreign gas is used in the Netherlands. The high methane content in imported gas makes it high-calorific gas, which installations such as our central heating boilers cannot handle. However, by adding nitrogen to imported gas, we can turn it into Groningen-quality, i.e. low-calorific, gas.

In order to put this solution into practice on a large scale, a decision was made in 2018 to build a nitrogen installation near the village of Zuidbroek in Groningen province. This location was chosen because it is where many gas transmission lines come together, making transmission from and to Zuidbroek the obvious choice. This installation will have the capacity to blend nitrogen with around 10 million cubic metres of imported gas on an annual basis. 
It consists of two parts: a blending station and a nitrogen plant. The nitrogen plant sucks in atmospheric air and separates it into nitrogen, oxygen, and several residual substances. While the oxygen is released, the nitrogen is fed into the blending station, where it is blended with high-calorific gas to make the low-calorific gas that is subsequently fed into our gas network.

The installation was initially scheduled to be ready on 1 April 2022, but like projects in almost all other industries this project suffered a delay due to the Covid-19 pandemic. Work on the installation was hampered by the various lockdowns, delays in the supply of materials, but also by staff shortages. It put the project back by around three months. 
Every year, Gasunie Transport Services (GTS) issues advice on how much gas will have to be extracted to guarantee gas supply in the Netherlands, factoring in the phase-out of extraction from the Groningen gas field. Due to the delay to the construction work and increased demand for Groningen gas from Germany, the advice issued previously has now been changed. GTS projects that, due to the delay, 7.6 billion cubic metres of gas from the Groningen field will be needed in 2022, assuming temperatures over the year will be at the average level. In 2021, this was 7.8 billion cubic metres of gas. It is now up to the State Secretary for the Extractive Industries, Hans Vijlbrief, to make the final decision. He is currently examining the various options.

Barring any setbacks, the Zuidbroek nitrogen installation will be up and running around the summer of 2022. And while it is the Netherlands’ ultimate ambition to have an entirely natural-gas-free energy system, we still have a long way to go to achieve that. The nitrogen installation will, therefore, be a key part of our gas infrastructure for many years to come, as we transition to a natural-gas-free Netherlands, but above all also en route to final closure of the Groningen gas field.