Navigating the Methanol Paradox: A Prescriptive LCA-DEA Framework for Benchmarking Diverse Production Pathways

High Resolution Image Download MS PowerPoint Slide Methanol is a pivotal carrier for the emerging hydrogen economy, yet the environmental trade-offs between conventional fossil-based and emerging renewable production pathways remain complex. This study introduces an integrated benchmarking framework coupling comprehensive process modeling, Life Cycle Assessment (LCA), and Super-Efficiency Data Envelopment Analysis (DEA) to evaluate 11 methanol production pathways. Results identify five renewable-integrated benchmarks, led by hydropower-driven CO 2 hydrogenation, which achieves top performance by bypassing syngas production and eliminating fossil-fuel dependency. Conversely, pathways relying on the fossil-intensive grid remain inefficient due to the high toxicological and carbon intensity of compression and O 2 production. Beyond identifying bottlenecks, the DEA framework endogenously delineates technological mentors for suboptimal pathways based on structural kinship and feedstock homology, ensuring that prescribed retrofit trajectories are practically feasible. While CO 2 hydrogenation maximizes theoretical efficiency, reforming-based routes can achieve significant gains by optimizing stoichiometry via CO 2 /O 2 integration. However, a critical Energy-Water-Land nexus trade-off is uncovered: renewable integration effectively neutralizes toxicity but triggers burden shifting toward increased land and water consumption. Furthermore, the carbon capture stage remains a net-positive GWP contributor unless decoupled from fossil-based thermal utilities. By mapping these structural bottlenecks and feasible benchmarks, this work establishes a rigorous mathematical basis for strategic retrofitting, charting a clear technological roadmap toward a circular carbon economy.