Gasunie Prepares for High Nitrogen Future

The Dutch natural gas transport grid operator Gasunie is preparing an expansion of its capacity to convert high-calorific into low-calorie gas as NAM's output from Groningen falls and GasTerra's sales contracts remain in place. It aims to take an investment decision before the end of this year.

Natural gas from the largest domestic gas field, Groningen, contains nitrogen, an inert gas, and the Dutch natural gas grid is suitable for the transport and distribution of this low-calorie gas. By mixing gas with nitrogen, before it is injected in the grid, Gasunie makes it acceptable for Dutch and foreign household appliances.

In 2012 it opened a salt cavern in Heiligerlee for storing nitrogen – the first in The Netherlands. At the same time, in nearby Zuidbroek, Gasunie started to use facilities to extract nitrogen from the air and inject it into the grid or send it to Heiligerlee. Gasunie can call on the underground storage at peak times, to ensure there is sufficient gas of the correct quality. The extension of Zuidbroek will probably have a capacity of 180,000 m³ nitrogen/hour, about tenfold the existing installation.

Dutch gas grid (Credit: Gasunie)

This will enable Gasunie to transfer on a yearly basis 6-9bn m³ high-calorific gas into 7-11bn m³ low-calorie gas, which is about 21% of the domestic consumption. As Dutch gas supplies are gradually declining, gas from other countries has started to occupy an increasingly prominent role in the Dutch energy mix. During the first six months of 2016 nitrogen use rose to 740mn m³. During the same period in 2015, this was 429mn m³.

Belgium and Germany

Belgium is an important importer of Dutch natural gas, but also imports lesser quantities from other countries, mainly Norway, Qatar and the UK. Some parts of the Belgian grid is suitable for low-calorie gas, others for high-calorie gas. Belgium has four blending stations, to add nitrogen or to mix both types of natural gas, to prevent possible deficits in one or the other during severe winters.

The lower Dutch production will also affect Belgium. By 2030 Dutch gas export to Belgium – as to France and Germany – will be finished. Contrary to the Netherlands Belgium has no plans to build additional nitrogen capacity. Instead, it gradually adapts its grids to be suitable for high-calorific gas. Germany also converts its grids for high-calorific gas. The first German projects already have been completed and new conversion projects have been announced.

Koen Mortelmans