Sustainable waste valorization process selection through AHP and advanced Interval Valued Fermatean Fuzzy with integrated CODAS

The sustainable waste valorization process selection is a complex process in real life scenarios. In this study, a comprehensive evaluation of biological and thermal valorization processes is performed. The Interval Valued Fermatean Fuzzy Set (IVFFS) methodology with the integration of the Dombi Operator (DO), is applied combining with the Analytical Hierarchy Process (AHP). This analysis considered four distinct municipal solid waste (MSW) valorization processes—anaerobic digestion (AND), gasification, pyrolysis, and hydrothermal gasification (HTG)—assessing their effectiveness based on economic, environmental, technological, and social-governance criteria through IVFFS with Dombi Operator (DO). Advanced Combinative Distance-Based Assessment (CODAS) was applied for ranking these processes based on expert opinions and existing literature on the subject. According to the IVFFS assessment results, the thermal valorization technique gasification identified as the sustainable process with assessment score (A_s) of 0.063, followed by pyrolysis and HTG with A_s of 0.009 and −0.033, respectively. The threefold validation, encompassing weights variation, rank reversal, and changing DO value, consistently supported the finding that gasification stands out as the most sustainable process. Finally, policy implications derived from this study findings offer valuable guidance for policymakers seeking to endorse and promote these sustainable waste valorization processes in developing countries.