Nitrogen+Syngas 372 Jul-Aug 2021
31 July 2021
The new carbon?
“Nitrogen management needs to be higher on the agenda of global environmental conferences”
At a time when green (or maybe blue) ammonia is being looked to as a way of reducing carbon emissions, substituting for hydrocarbons in a variety of potential uses, a conference held at the start of June was a reminder that nitrogen, its neighbour on the Periodic Table, is by no means off the hook on the environmental front. The Eighth Global Nitrogen Conference – held over from last year because of Covid-19, and this year held virtually, as most events are for the time being – was the latest in a series of tri-annual meetings convened by the International Nitrogen Initiative (INI), with support from the UN Economic Commission for Europe (UNECE) and the German Ministry of the Environment. The INI grew out of the 1979 UNECE Convention on Long-range Transboundary Air Pollution and 1999 Gothenburg Protocol, and is concerned specifically with ‘reactive nitrogen’ (i.e. nitrogen not tightly bound to itself in a triple bond, which makes up 78% of the air around us).
Many of the concerns will be familiar to the nitrogen industry – the release of nitrous oxide (N2O) into the atmosphere, with its global warming potential, NOx pollution and its effects on health, and nitrate migration into water courses and consequent algal blooms and anoxic ‘dead zones’ in river estuaries, as well as deleterious effects on ecosystems and soil quality. While acknowledging the benefits that the Haber-Bosch process has brought in terms of feeding a growing global population, the INI argues that it has also led to a 100 year period where Earth’s nitrogen cycle has been in imbalance, with an increasingly large load of reactive nitrogen roughly doubling the amount of nitrogen circulating in the environment over that time, and eventually finding its way into air and water.
NOx and N2O abatement has been a success story for the nitric acid industry in particular over the past two decades. However, in spite of the success of the process industry in dealing with N2O emissions, these have still risen globally by 30% since 1980, with most N2O lost to the atmosphere now coming from agriculture, as a result of the breakdown of urea and ammonium nitrate in the field. N2O is the third largest contributor to climate change after carbon dioxide and methane. Meanwhile, the effect of ammonia emissions from agriculture and other sources on human health is a subject of increasing concern.
The Global Nitrogen Conference, which was originally to have been held in Berlin, produced what it called the Berlin Declaration, which said that “better management of humanity’s relationship with nitrogen is central to the success of the [UN] Sustainable Development Goals.” To this end, it endorsed the 2019 Colombo Declaration to halve nitrogen waste by 2030 and called for measures to improve nitrogen management practices and technologies for use at the farm level, and the recovery of nitrogen from manures, wastewater and industrial effluents, as well as promoting foods “with lower nitrogen footprints and a higher share of plant-based protein sources”. Countries should set national nitrogen targets/ budgets – Germany is already on the verge of doing so, and nitrogen management needs to be higher on the agenda of global environmental conferences.
There is some evidence that this is happening. In December 2020 the UNECE adopted a draft guidance document on international sustainable nitrogen management in consultation with the INI. Much of the focus going forward will be on farming practises, and how and when and in what quantity nitrogen fertilizer and manures are applied to fields, with increasing use of precision agriculture to try and avoid volatilisation losses. But industry will also no doubt be required to play its part, via an increasing focus on slow and controlled release products – the UK’s recent consultation on banning or restricting the application of urea that is not treated with a urease inhibitor is one such straw in the wind, and it may lead to an increasing move towards nitrate fertilizers like AN and CAN in Europe.
As yet, nitrogen is not the new carbon – there is nowhere near the same focus and pressure at an international level. But momentum is building for an overhaul of how we look at nitrogen and its role in the environment, and while efforts so far have been piecemeal, and mainly on a national or regional level, more coordinated and potentially far reaching policy changes may only be a few years down the line.
