Integrated Phosgene and Steel Production: Combining Process Optimization and Life Cycle Assessment to Minimize Greenhouse Gas Emissions

Harnessing basic oxygen furnace gas (BOFG) from steel mills as an alternative carbon source is a promising option to reduce greenhouse gas (GHG) emissions. This study explores two process concepts to purify CO from BOFG for subsequent phosgene synthesis: (i) vacuum pressure swing adsorption (VPSA) yielding pure CO, and (ii) CO2 separation via monoethanolamine (MEA) absorption producing CO-enriched gas. By combining process optimization with life cycle assessment (LCA), process parameters are identified that minimize GHG emissions. The MEA concept can reduce emissions by up to 60 %, whereas the VPSA concept achieves a reduction of 47 %. Utilizing renewable energy enables further reductions, indicating additional environmental benefits in the future. Overall, both processes effectively produce low-carbon CO for phosgene synthesis, with increasing environmental benefits in future energy systems.