N 2 O as a Reactant Rather Than Pollutant at Wastewater Treatment Plants: Life Cycle Assessment and Technoeconomic Analysis of N 2 O-to-Phenol

High Resolution Image Download MS PowerPoint Slide N 2 O emissions-reducing technologies are essential to reduce wastewater treatment plant (WWTP) greenhouse gas (GHG) emissions. In this study, we perform a life cycle assessment (LCA) and technoeconomic analysis (TEA) of a technology that intentionally produces N 2 O from WWTP N and uses this gas as an oxidant in the production of phenol and co-product N 2 . We compare the cost and sustainability of producing phenol and N 2 with this technology and via conventional routes (cumene-to-phenol, cryogenic distillation, and pressure swing absorption to N 2 ). Depending on the co-product allocation method, the median cumulative energy demand of the phenol produced from WWTP nitrogen is 30% to 50% higher than phenol from the cumene process, while the global warming potential of phenol produced via this pathway ranges from 10% lower to 40% higher than conventional routes to this chemical. However, depending on the WWTP size, level of N 2 O recovery, and market price of feedstocks and products, producing phenol at WWTP with this technology can produce a positive internal rate of return. We conclude that this technology could be applicable for large-scale WWTPs, but technological advancements are needed.