While interest in the use of ammonia as a hydrogen carrier and zero-carbon fuel grows, a Princeton-led team of researchers found that a mismanaged ammonia economy could have unwanted environmental consequences. (adobe.stock.com)
Ammonia, a main component of many fertilizers, could play a key role in a carbon-free fuel system as a convenient way to transport and store clean hydrogen. The chemical, made of hydrogen and nitrogen (NH3), can also itself be burned as a zero-carbon fuel. However, new research led by Princeton University illustrates that even though it may not be a source of carbon pollution, ammonia’s widespread use in the energy sector could pose a grave risk to the nitrogen cycle and climate without proper engineering precautions.
A mismanaged ammonia economy could ramp up emissions of nitrous oxide (N2O), a long-lived greenhouse gas around 300 times more potent than CO2 and a major contributor to the thinning of the stratospheric ozone layer. It could lead to substantial emissions of nitrogen oxides (NOx), a class of pollutants that contribute to the formation of smog and acid rain. And it could directly leak fugitive ammonia emissions into the environment, also forming air pollutants, impacting water quality, and stressing ecosystems by disturbing the global nitrogen cycle.
“We know an ammonia economy of some scale is likely coming,” said research leader Amilcare Porporato, the Thomas J. Wu ’94 Professor of Civil and Environmental Engineering. “And if we are proactive and future-facing in our approach, an ammonia economy could be a great thing. But we cannot afford to take the risks of ammonia lightly. We cannot afford to be sloppy.”
