Environmental life cycle assessment of an ammonia production process through cumulative exergy demand and ReCiPe: a focus on power generation from natural gas and biomass

The environmental impacts of the ammonia production process are because of the discharge of harmful chemicals as well as the high energy demand. One way to control its environmental impacts in the electricity transition phase, is the natural gas/biomass-based scenarios. This life cycle assessment (LCA) study, which has used ReCiPe and cumulative exergy demand (CExD), proves that natural gas is not right option for this specific case because the natural gas-based scenarios have more burdens than the residual fuel oil-based scenarios especially regarding fossil depletion (0.72%), human toxicity (14%), freshwater ecotoxicity (23%), particulate matter formation (33%), marine ecotoxicity (37%), and terrestrial acidification (40%). Moreover, this study shows that it is possible to reduce the environmental impacts without retrofitting the heart of process technology using the biomass-based scenarios. This paves the way for a sustainable ammonia process under the energy transition scenarios where retrofitting the process heart is not desired.