Discovering Net-Zero Chemical Processes and Pathways by Developing Circular Reaction Networks and Their Hierarchical Screening
Sunghoon Kim, Bhavik R. Bakshi · Industrial & Engineering Chemistry Research · 2025
Achieving net-zero emissions in the chemical industry necessitates innovative reaction pathways and process designs. This study introduces a novel framework employing a double-direction search, integrating retrosynthetic analysis and structural similarity, to construct cradle-to-cradle circular reaction networks. Multilevel (chemistry, reaction, and process) and multiscope (reaction to life-cycle) optimization ensures alignment with both economic viability and environmental sustainability objectives, leading to more holistic solutions. A hierarchical approach efficiently streamlines the design space exploration, while technology readiness levels (TRLs) help determine the novelty of selected reactions. A methanol production case study from natural gas demonstrates the framework’s ability to uncover novel net-zero pathways. Notably, formaldehyde emerges as a key intermediate, and a direct synthesis route from recycled CH 4 (via CO 2 ) significantly enhances overall performance. Integrating low- and medium-TRL reactions with mature technologies seems promising for substantial cost savings and considerable greenhouse gas reduction, outperforming current commercial and emerging options. This research advances the critical development of sustainable, circular chemical processes that effectively support ambitious net-zero targets.