An integrated approach for sustainability assessment with hybrid AHP-LCA-PI techniques for chitosan-based TiO₂ nanotubes production

Designing a sustainable process requires the aid of systematic multivariate assessment method that considers the dimensions of economic, social and environmental impact. This work presents a sustainability assessment framework for the commercial production of chitosan-based titanium dioxide (TiO₂) nanotubes using a hybrid method consisting of analytical hierarchy process (AHP), life cycle assessment (LCA) and process integration (PI) techniques. Despite the attractive financial return of the case study as mentioned, its adverse environmental impacts pose challenges to commercialisation due to large consumption of chemicals and waste discharge. Hence, five production alternatives with resource conservation options were evaluated. AHP was adopted as a multiple criteria decision-making tool considering all three dimensions of sustainability; the latter include capital and operating costs, handling risk, alongside with environmental criteria, namely cumulative energy demand (CED), global warming potential (GWP) and water depletion (WD). The selected alternatives were validated through experiment works. Reutilisation of calcium chloride was determined to be the preferred configuration as it fulfilled all three sustainability dimensions, as compared to other alternatives.