A scenario-responsive siting framework of CO₂ capture and electrochemical conversion systems using integrated spatial and multi-criteria decision analysis

Abstract

The growing interest in electrochemical CO₂ reduction to value-added hydrocarbons and oxygenates reflects the urgent need for sustainable carbon utilization pathways. While a range of products has been demonstrated, only a few have matured electrocatalysts with systematically optimized electrochemical performance metrics. These metrics critically affect overall production costs. Therefore, the need for a flexible siting framework that actively identifies optimal CO₂ electrolyzer locations based on plant specific sizing and production requirements is warranted for the advancement of this technology. We present a scenario-responsive decision-making framework for CO₂ electrolyzer siting, integrating Geographic Information Systems (GIS), the Decision-Making Trial and Evaluation Laboratory (DEMATEL), and the Analytic Network Process (ANP). Three spatial siting factors were defined in this study as key factors influencing site suitability, including land cost, transportation accessibility, and CO₂ source accessibility. The framework model's interdependencies among siting factors and computes land suitability using both general and scenario-adjusted weightings reflecting product type and plant capacity. Suitability of siting was evaluated for 15 deployment scenarios combining three capacities (1 MW, 20 MW, 100 MW) and five products (CO, HCOOH, C₂H₄, CH₃OH, C₂H₅OH) in two industrial clusters in Texas Houston and San Antonio. Results reveal regional differences: Houston's suitability patterns were highly sensitive to scenario weightings, while San Antonio exhibited more stable patterns. The model identified a small set of high-performing parcels, including one optimal site per region across most scenarios. These findings underscore the importance of city-specific siting, as regional variations limit the reliability of generalized assumptions.