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No. 487: Assessment of the potential environmental impacts of a major ammonia spill from a Power-to-X plant and from shipping of ammonia in Greenland

Fritt-Rasmussen, J., Gustavson, K., Aastrup, P., Agersted, M.D., Boertmann, D., Clausen, D.C., Jørgensen, C.J., Lansø, A.S. & Mosbech, A. 2022. Assessment of the potential environmental impacts of a major ammonia spill from a Power-to-X plant and from shipping of ammonia in Greenland. Aarhus University, DCE – Danish Centre for Environment and Energy, 88 pp. Scientific Report No. 487. http://dce2.au.dk/pub/SR487.pdf

Summary

The Government of Greenland is considering putting out to tender hydropower potentials (> 100 MV). The intension it to use the generated power from the potential hydropower plants to produce ammonia in a Power to X (PtX) plant. As part of this process, Aarhus University, DCE – Danish Centre for Environment and Energy, has prepared an overall assessment of the potential environmental impacts from a major worst-case accidental release or spill of ammonia in relation to production and transportation of ammonia in a PtX plant or by shipping in Greenland. The tender material designates three potential sites for production and shipping as well as the quantities of ammonia that can be spilled in the event of a major accident.

The three sites are: Kangerlussuaq (Sdr. Strømfjord), Kangerlussuatsiaq (Evighedsfjorden) and Nuup Kangerlua (Godthåbsfjorden)

Liquid anhydrous ammonia (LNH3) is highly soluble in water and when released into the environment, it will also evaporate and react with water in the air. It will form a white cloud that will drift with the wind and spread highly toxic gasses. It will poison the organisms that it passes, and subsequently some of the ammonia will be deposited on vegetation, soil and water. Ammonia is highly toxic and exposure to elevated concentrations can be fatal to humans, animals and plants. Ultimately, it can cause disappearance of some species in the affected area for a period of time. However, ammonia is neither persistent nor does it bioaccumulate, and it is readily diluted and degraded in the environment. Thus, an accident will have some acute lethal effects where local population sizes may be reduced, followed by a recovery period whose length is dependent on the population status and reproductive potential. No toxic compounds will be left in the area after the acute phase.

For each of the three areas, this report presents maps with densities and highlights species of concern, vulnerable species and other relevant biological elements and human uses of the area. For the assessment of the potential environmental impacts of a major ammonia spill, modelled values and estimates of ammonia concentrations in the environment and thresholds values for toxicity are included and used to estimate potential risk zones of environmental impacts. The overall conclusions from the assessments are that a major, worst-case accidental ammonia spill would likely cause severe toxic damages up to several kilometres from the spill site, and some scenarios show that organisms might be affected more than 10 km from the spill sites. The actual impact of a spill will, to a large extent, depend on the weather conditions, the size of the spill as well as the recovery time of the affected populations.

A part of the project was also to conduct a literature search on historical spills. The ammonia industry is large and global and has accumulated experience from more than 100 years of production. From the literature it is evident that focus in the ammonia industry and the regulating authorities is on safety and prevention and on the implementation of Best Available Techniques (BATs) to avoid a large accident. It is very important that the highest safety standards are implemented to avoid an accident, also to save human lives. A large accident, with ammonia releases in the same order of magnitude as our spill scenarios, has been estimated to happen once in 10,000 years for a modern ammonia factory (DSB 2019).