Impact of Hydrogen and Ammonia on Surface Air Pollution.

Hydrogen and ammonia fuels are being explored as cleaner and sustainable energy alternatives to fossil fuels, due to their potential for decarbonization. The production of renewable energy-based hydrogen converted into green ammonia offers a more efficient solution for storing and transporting energy than gaseous hydrogen. However, both ammonia and hydrogen can indirectly lead to air pollution.

Ammonia, if leaking to the atmosphere, plays a role in forming secondary aerosols, generating particles like ammonium nitrate that add to fine particulate matter (particulate matter with diameter <2.5 micrometers; PM2.5). Additionally, the production of oxides of nitrogen (NO_X) gases during ammonia combustion contributes to tropospheric ozone formation and can influence aerosol abundance (as NO_X may lead to less aerosols and not necessarily more). Hydrogen, if leaked to the atmosphere, will impact tropospheric ozone and possible aerosols through a complex chain of chemical reactions.

Our research aims to assess the potential air quality effects of shifting to a hydrogen and ammonia-based economy.

Using simulations from the three-dimensional global chemical transport model (OsloCTM3), we are investigating the impacts of hydrogen and ammonia on key air quality parameters, with a specific focus on surface concentrations of ozone and PM2.5.

We will attempt to assess the benefits of this energy transition in relation to the reduction of atmospheric pollutants associated with fossil fuels. In the case of ammonia, we will compare air pollution impacts across different emission sectors. Future work will involve the analysis of chemistry-climate model simulations.