Nitrogen: the savior in our decarbonization wrestles?

It may not be clear to the average consumer, but nitrogen fulfills a key function in the supply of Dutch natural gas to millions of households in Europe. And by doing so, it is an unexpected piece in the European energy puzzle towards a CO2 neutral economy. How has this simple molecule, a main component of the air that we breathe, found its way into the debates about greenhouse gasses and global warming?

Groningen gas valve

To understand the role of nitrogen, one has first to recognize that in the Netherlands, and parts of Germany, Belgium and France, gas consumption has since the 1960’s been based on its nearest main supply source: the Groningen field. Over decades, many millions of household appliances for cooking and heating, greenhouses, small industries and many CHP have been installed and operated in these regions, purposely manufactured to function on the Groningen gas quality. Although it was acknowledged that this quality was distinctly different from the prevailing gas types in the rest of Europe, the size of the Groningen reservoir offered sufficient supply security for long into the future.

Come 2019 however, this future seems to be nearing its end now. Not so much because the gas reserves are becoming depleted, but because of the effects of their extraction on Groningen soil stability and the public and political pressures resulting from them. Last year, the Dutch government has decided that Groningen gas production shall quickly be scaled down to a quarter of its original volume and ultimately be discontinued entirely to minimize further earthquake risks.

Ripple effects

And here we enter the pan-European picture of total energy supply and demand and its CO2 reduction targets. Because in the tightly integrated networks by which electricity, gas and heat are exchanged in Europe, such drastic decision by the Netherlands has immediate ripple effects to the energy balance of the entire region. How to compensate for this important reduction of supply? Should this be seen as an opportunity to enforce renewable energy and forget about carbon-based gas altogether, as some claim? Or increase Europe’s gas dependence of Russia, which despite its historic reliability appears to become increasingly debatable? Should hydrogen play a role?

In Europe, we have some experience with how the energy markets may answer such questions. Operators seek the lowest cost energy source. Lately, when Germany decided to phase out nuclear energy at a pace that renewables could not match, power generation shifted to cheap coal and lignite. Massive German public funds to subsidize solar and wind only led to overcapacity and cheap electricity, but without overall CO2 benefits.

How to avoid such undesirable situation to arise again when Groningen gas is taken out of the equation? And how to satisfy the millions of consumers with heating and cooking appliances that rely on Groningen gas quality?

It is here where nitrogen comes to the rescue. At least for the intermediate term.

Nitrogen the savior?

With nitrogen, produced from air, Groningen quality gas can easily be made from international gas types by admixing measured quantities of it. At a number of locations in today’s Dutch gas network, nitrogen blending facilities already exists where this is performed. Especially during the winter heating season, Groningen field production is below demand and increasing volumes of imported gas are blended with nitrogen to make up for the shortage. The pipeline grid would be capable of fully replacing Groningen gas by such produced mixture. And importers stand ready to increase their volumes, by LNG ships from the US or pipelines from Russia. So yes: nitrogen could come to the rescue of the many households seeking continued supply of their gas quality when the Groningen valve is closing. The only next question is however: how much nitrogen production and blending capacity will be needed, and when?

How much then?

Last year, after some hesitation, Gasunie Transport Systems found sufficient justification to decide for a new nitrogen production and blending plant near a gas import station at the German border. A consortium in which Bilfinger Tebodin takes part as engineering contractor, has been assigned the project, called Zuidbroek 2. Planned start-up is in 2022.

But further on into the future, justifications are cumbersome. What if consumption of Groningen gas quality shrinks steeper than expected due to initiated programs to replace appliances, despite current delays by consumer costs and shortage of skilled technicians? And when unforeseen electrification advancements shift demand to powerplants that run on international gas or other fuels? Adding to the uncertainty: economic recessions will reduce demand altogether. Furthermore, supply may add unpredictability with Groningen earthquake risks largely uncontrollable and public responses even more so. Effects can be expected from the energy transition to renewables. It is almost impossible to foresee how all these will impact the equation in Europe.

A new role

By offering continued availability of Groningen quality gas in such unpredictable future, nitrogen can be seen to cushion general energy supply/demand dynamics, with blending facilities acting as if they were some sort of safety valve. Indeed, it will contribute to avoiding additional coal and lignite being burned in powerplants instead, which would emit double quantities of CO2. As an alternative to costly new installations for capturing CO2 from the chimneys of such powerplants, nitrogen will also help avoiding obsolescence of already existing and publicly funded gas network infrastructures.

Needless to say now that nitrogen production and blending capacities shall be plentiful. For such simple air molecule to offer such profound effect in our climate ambitions, the opportunity shall not be left untouched.

Shall it then be Zuidbroek 3 or Maasvlakte 1? Actually, with the gas network as tightly integrated as it is, this doesn’t seem to make too much difference. As long as it comes.

Аuthor: Maurice Houben

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