Ammonia is widely used in the agricultural sector for the production of fertilizers, and it has received particular attention in the last decade as a promising fuel to reduce carbon emissions. Ammonia is a carbon-free molecule which produces no carbon dioxide emissions when burned. Liquid ammonia also requires less space than liquid hydrogen, making it a good candidate as an alternative fuel and energy carrier for long-haul transport. Green ammonia is carbon neutral. Nevertheless, several factors need to be considered, particularly in relation to safety when scaling-up its use, handling, and storage in the marine environment.
In fact, ammonia is classified as hazardous due to its toxicity, corrosivity and flammability. Prolonged exposure can irritate and burn the skin, mouth, throat and eyes, and result in lung damage and potentially death. Fires and explosions can also occur when ammonia mixes with air concentrations within its flammability range (15-28% in air). Ammonia also represents a threat to aquatic life. Un-ionized ammonia is extremely toxic to fish, causing gill damage, internal organ damage, skin damage and death. It also fuels the growth of marine algae. In case of large spills of liquid ammonia into the sea, the risk of rapid evaporation cannot be excluded yet.
The Knowledge Building Project (KSP) SafeAm aims at accelerating the implementation of new value chains for ammonia as a zero-emission fuel and energy carrier by improving safety systems’ design and procedures for handling accidental spills. SafeAm will develop an experimental dataset and complex thermo-physical models to increase the quantitative understanding of ammonia dissolution, mixing and evaporation. A new tool (PIRATE) for calculating the ammonia uptake in seawater and the amount dispersed into air will be created. Risk trade-offs, KPIs and regulatory guidance will also be provided through the project.
Ammonia (NH3) has intrinsic risks due to toxicity and flammability. While used as fertilizer for decades, accidents leading to severe injuries and deaths have been reported during production, storage and use. Concerns about NH3 safety for large-scale implementation in the maritime offshore industry are raising, especially about the effects of large releases on and into water. SafeAm will secure the feasibility of ongoing efforts and investments towards emerging NH3 technologies for use on the waterways. This will be accomplished by a full-chain cross-disciplinary effort, closing key knowledge gaps. Through experiments with increased fidelity and an expanded parameter space combined with thermodynamics modelling, SafeAm enables the quantitative description of the effects of LNH3 spills on and into water. This will be represented by a thermodynamic model developed in the framework of the project, which gives input to NH3-dispersion models both in air and in water. Based on this, the extent of the toxic cloud in atmosphere and the hazards for humans will be assessed for relevant and realistic spill scenarios. In addition, novel environmental risk-maps based on LNH3 spill-to-sea behaviors will be produced. Risk trade-offs between the benefit to the environment related to climate change and new risks to human and environment will be used as support for societal acceptance. Finally, input to standardization and guidelines will result from the work in SafeAm, defining up a set of safe handling procedures for application of NH3 over water considering the specific risk factors and criticalities. The findings thus will widen the horizon for quantitative risk assessment of alternative fuel applications.