Production of Ammonium Formate Using Byproduct Waste Gas: Economic and Environmental Perspective

Reducing greenhouse gas emissions from the steel industry has become increasingly important. One viable approach is the valorization of CO-rich byproduct gas into high-value chemicals, rather than its conventional use as an energy source, which typically results in substantial CO2 emissions. In this context, this study proposes biocatalytic processes for producing ammonium formate (AF) using the CO contained in steel byproduct gas. To evaluate the economic and environmental feasibility of the proposed process in comparison with a conventional coal-based process, we conducted a comprehensive analysis including technoeconomic analysis and life cycle assessment. The minimum selling price of AF from the proposed process was estimated at $814.1 per ton-AF, which is comparable to that of the conventional process. This result highlights the need for heat pump integration to further improve economic performance. Moreover, the proposed process exhibited a lower environmental impact, with 3.1 kg-CO2 eq/kg-AF, compared to 5.9 kg-CO2 eq/kg-AF from the coal-based process. These findings demonstrate that utilizing byproduct gas for AF production not only enhances resource efficiency but also offers a promising pathway for greenhouse gas reduction in the steel industry.