Kristina Hiir

Across production and processing systems, biological residuals are inconsistently defined, with the same materials treated as waste, by-products, or resources depending on context. This ambiguity constrains the identification of valorization pathways and limits the design of sustainable and resource-efficient operational strategies. This study addresses the issue by compiling a sector-resolved inventory of 94 bioresiduals across 12 bioeconomy-related activities. Analyzing 1763 firm–bioresidual observations from a national survey in Estonia using binomial logistic regression. The results show that bioresidual use is primarily shaped by operational and data-handling practices, particularly collection and accounting, rather than by structural firm characteristics. Separate collection emerges as a key precondition for higher-value use, while accounting practices are associated with external and energy-related pathways by increasing visibility and traceability. In contrast, irregular or seasonal bioresiduals tend to default to waste handling due to variability and perishability. The findings also indicate that many effective uses remain internal to production systems and are under-documented. Improving the definitions and monitoring practices of bioresiduals could support more efficient and sustainable resource management by reducing biowaste generation and enhancing coordination across value chains, thereby fostering the development of a circular bioeconomy.