A multi-index circularity framework for agro-residue based paper systems: Integrating performance, degradability, and effluent valorization

The pulp and paper industry commonly applies material flow analysis to evaluate circular economy transitions through resource recirculation metrics. However, focusing only on recirculation rates overlooks important environmental impacts and the overall value of the system, especially in biobased production systems that use agricultural waste as main materials. Circularity assessment therefore requires integration of material performance, degradability, and effluent management dimensions. This study proposes a multi-index quantitative framework for circularity assessment. The framework incorporates the Material Circularity Indicator (MCI) to ensure comparability while introducing three complementary indices: the Eco-Efficiency Circularity Index (EECI), the Durability–Degradability Balance (DDB), and the Circularity-Extended Score (CES). These indices use easier math formulas to assess things like strength, weight, how quickly materials break down, how long it takes to degrade, and waste produced. The framework was used on three types of agricultural waste—rice straw, black garlic husk, and corn cob by using data from lab tests and information from research. Results show that circularity rankings vary across indices, revealing distinct performance–environment trade-offs. The proposed method offers an engineering-oriented decision-support tool for feedstock selection that enhances transparency and reproducibility in laboratory-to-pilot-scale circularity assessment.