A hybrid MCDM framework for sustainability assessment of helium extraction from natural gas: a real case study

Extracting helium from natural gas is crucial for securing this strategic resource. However, supply chain vulnerabilities due to finite reserves and geopolitical constraints necessitate the development of sustainable extraction processes. This study evaluates two real helium extraction processes—a cryogenic separation process and an integrated membrane-pressure swing adsorption (PSA) process—using a hybrid multi-criteria decision-making (MCDM) framework. The framework includes three stages: criteria system formulation, criteria weighting, and alternative prioritization. A five-dimensional criteria system with 20 quantifiable metrics covers technical performance, environmental impacts, ecological and human health risks, economic viability, and inherent safety. The weighting stage integrates subjective expert judgments (via the Best-Worst Method) and objective data characteristics (through the Method based on the Removal Effects of Criteria) using game theory to avoid biased judgments. The prioritization stage employs the Measurement of Alternatives and Ranking according to Compromise Solution method, which maintains ranking stability and effectively addresses trade-offs in high-dimensional decision spaces. Results show that the integrated membrane-PSA process has a higher integrated sustainability score (0.7792) than the cryogenic process (0.4834). Ranking reversal, sensitivity, and comparative analysis verify the stability of the rankings, indicating that the integrated membrane-PSA process is more sustainable. In general, this study pioneers the sustainability assessment of helium extraction processes using MCDM methods, demonstrating that a comprehensive criteria system, unbiased weighting approach, and rational prioritization model are essential tools for future assessments and comparisons of the helium industry. The findings suggest that prioritizing improvements in recovery efficiency, energy use, and cost-effectiveness is essential for advancing sustainable helium extraction. These results also provide actionable insights for policymakers and industry stakeholders in technology selection and investment planning.