(286c) Developing a Nitrogen Circular Economy By Recovering and Utilizing N2o As a Feedstock for Phenol Production

Excess reactive nitrogen in the environment has led to a disruption of the global nitrogen cycle. A large fraction of that nitrogen ends up in wastewater treatment plants, where it is released back into the atmosphere as diatomic nitrogen or nitrous oxide (N₂O), a potent greenhouse gas. However, with an increasing emphasis on developing a nitrogen circular economy, various nitrogen recovery technologies are being investigated. One of these technologies is called the coupled aerobic-anoxic nitrous decomposition operation (CANDO). CANDO can convert ammonia in wastewater into N₂O, which is then co-combusted with methane for additional energy generation. However, N₂O is also a powerful selective oxidant that can be used for chemical production. Recovering N₂O from wastewater to produce industrially relevant chemicals could advance the nitrogen circular economy, but its environmental impacts have not been explored.

In this study, we investigate recovering N₂O from wastewater and utilizing it for phenol production, as traditional phenol production from the cumene process is energy intensive. By developing process models for both the N₂O recovery and the phenol production utilizing N₂O, a life cycle assessment was completed to compare the cumulative energy demand and the global warming potential (GWP) to the cumene process and other nitrogen recovery technologies. Results show that phenol production utilizing N₂O has lower energy demand and GWP than the cumene process. The results can encourage further exploration of using N₂O as an oxidant for the production of other industrial chemicals.