Development of Sustainability Assessment Framework for Preliminary Design of Chemical Process: Hydrogen Production as Case Study

Sustainable process design has become increasingly important in transitioning from conventional to sustainable chemical production, yet comprehensive sustainability assessment at the preliminary design stage remains a challenge. This study addresses this gap by proposing a hierarchical framework that integrates the Principles, Criteria and Indicators (PC&I) method with multi-criteria decision-making (MCDM) tools, including entropy weighting, TOPSIS, and weighted addition. The framework guides the systematic selection of sustainability indicators across economic, environmental, and social dimensions. To validate its applicability, a case study on hydrogen production via four process routes, natural gas reforming, biomass-derived syngas, methanol purge gas recovery, and alkaline electrolysis, is conducted. Results show that the methanol purge gas process exhibits the best overall sustainability, followed by biomass syngas and alkaline electrolysis. The case demonstrates the framework’s capability to differentiate between alternatives under conflicting sustainability dimensions. This work provides a structured and replicable approach to support sustainable decision-making in early-stage chemical process design.