Sustainability Prioritization of Sludge-to-Energy Technologies based on An Improved DS/AHP Method

Selecting the most sustainable technology for sludge-to-energy among multiple alternatives is vital for promoting the development of resource recovery. This study aims at developing a sustainability assessment framework for the prioritization of sludge-to-energy technologies with the considerations of incompletion and uncertainty problems. The traditional Dempster–Shafer analytic hierarchy process (AHP) method has been adapted to gray conditions. AHP has been used to determine the weights of the criteria for sustainability assessment and rank the alternatives. Three technologies including sludge incineration to electricity, sludge anaerobic digestion for biogas to electricity through gas engine, and sludge anaerobic digestion for biogas to electricity through fuel cells have been studied by the proposed method, and the technology “sludge anaerobic digestion for biogas to electricity through fuel cell” has been recognized as the most sustainable technology for sludge-to-energy, followed by “sludge anaerobic digestion for biogas to electricity through gas engine,” and “sludge incineration to electricity” in the descending order. The results show that the proposed method is feasible for prioritizing the technologies for sludge-to-energy.