Shades of sustainability: A comprehensive analysis of the carbon footprint in conventional blue ammonia and urea manufacturing processes

• LCA shows CO 2 accounts for 98.9 % of GHG emissions, driven by the Ammonia Converter Unit. • Methane and N 2 O contribute 0.74 % and 0.34 % of GHG emissions in blue ammonia production. • Integration of ammonia and urea plants reduces direct CO 2 emissions by approximately 19.4 %. • Indirect emissions rise by 9.9 % due to increased energy demands in the integrated process. • Study highlights emission hotspots and offers strategies for sustainable fertilizer production. The integration of sustainability principles into distribution networks presents a profound challenge for industries navigating today’s fast-paced and environmentally conscious landscape. Although a wealth of research has investigated the environmental impacts of industrial activities, there remains a significant gap concerning the life cycle assessment (LCA) of blue ammonia and urea production. This study aims to address this gap by offering a pioneering LCA of blue ammonia followed by urea, delivering an in-depth examination that spans the entire production process—from the initial raw material extraction to the final product stage. The analysis comprehensively evaluates both direct and indirect greenhouse gas (GHG) emissions, with a focus on key contributors, including carbon dioxide, methane, and nitrous oxide. Remarkably, the results show that carbon dioxide accounts for 98.9% of GHG emissions during the production of blue ammonia, while methane and nitrous oxide contribute 0.74% and 0.34%, respectively. Additionally, the integrated blue ammonia and urea process exhibits a slightly modified profile, with carbon dioxide accounting for 98.51%, methane for 1.00%, and nitrous oxide for 0.49%. The Ammonia Converter Unit, a crucial hotspot, is primarily responsible for these emissions. In the integrated blue ammonia and urea process, the utilization of captured carbon dioxide during urea synthesis significantly reduces direct emissions by approximately 19.4% compared to stand-alone ammonia production. However, this integration also increases indirect emissions due to higher energy demands, with electricity-related emissions rising by 9.9%. These findings underscore the trade-offs between direct and indirect emissions in the integrated process and highlight opportunities to enhance energy efficiency and adopt renewable energy sources. Through sensitivity analysis, the impact of feed gas composition on emissions and production efficiency was explored, identifying key process variables influencing sustainability outcomes. This detailed assessment highlights the environmental footprint of blue ammonia and urea production and offers actionable insights into potential sustainability strategies. By addressing emission hotspots in both processes, the study provides a foundation for targeted policy recommendations and supports the broader transition toward a more sustainable fertilizer industry.