Techno-Economic Analysis and Life Cycle Assessment of Hydroxylamine Eco-Manufacturing via Wastewater Electrochemical Reduction
Manish Mosalpuri, Wenzhen Li, Mark Mba Wright
Abstract
There is a growing need to develop novel technologies that reduce reactive nitrogen concentrations in wastewater streams and decrease our reliance on fossil fuel energy required to produce N-based chemicals and fertilizers. This study conducts a techno-economic analysis (TEA) and a life cycle assessment (LCA) of the electrochemical conversion of nitrate ions (NO 3 – ) present in wastewater to hydroxylamine (NH 2 OH), a valuable chemical intermediate. We employ experimental data and modeling assumptions to determine NH 2 OH production costs and life cycle emissions for a small-scale facility (producing 1500 kg-NH 2 OH/day) and a large-scale facility (producing 50,000 kg-NH 2 OH/day) integrated into a wastewater treatment plant. The present NH 2 OH production costs for the small- and large-scale facilities are estimated at $6.14/kg-NH 2 OH and $5.37/kg-NH 2 OH, respectively. The parameters dominating the electrochemical reactor cost are electrolyte, separations, and fixed cost, with their values as $1.48, $0.96, and $0.53/kg. Future cost reduction projections indicate that the present NH 2 OH production costs for the small- and large-scale facilities can be reduced to $2.79/kg-NH 2 OH and $2.06/kg-NH 2 OH (NH 2 OH market price = $1.72/kg), respectively, with improvements in the sensitivity analysis parameters. LCA results indicate that the proposed electrochemical pathway to produce NH 2 OH has lower life cycle impacts than the conventional pathway.