Advancing Environmental Sustainability through a Bio-Based Circular Economy A Systematic Literature Review of Biochemical Process Engineering

This systematic literature review (SLR) synthesizes 82 Scopus-indexed, peer-reviewed articles on the bio-based circular economy (BCE) in biochemical process engineering published between 2015 and 2025, following the PRISMA protocol. These articles were reviewed using descriptive analysis and thematic synthesis that mapped publication trends, domain themes, methodological patterns, and ongoing research gaps. Results show a marked growth in publications after 2020, indicating rising global attention to bio-based solutions for environmental sustainability. The evidence base is geographically skewed toward Europe, with smaller contributions from Asia and other regions, despite the global relevance of bio-based resources. This literature focuses on the bioeconomy, circular economy, and bio-based technologies, including biorefineries, bio-based fertilizers. Thematically, the literature focuses on the bioeconomy, circular economy, and bio-based technologies, microalgae applications, and bio-based plastics. Methodologically, the corpus is dominated by quantitative techno-economic assessments, life cycle assessments, and process optimization, while the integration of qualitative, theory-based, and governance-oriented studies is still relatively limited. Conceptually, the field remains fragmented, with insufficient integration across technological, policy, and socio-ecological dimensions. To address these gaps, this literature proposes three complementary frameworks: (i) an Integrated Assessment Framework for holistic sustainability evaluation, (ii) a Multilevel Governance Framework to support BCE transitions, and (iii) a Circularity Metrics Framework that emphasizes tiered use, quality preservation, and nutrient cycling. Overall, although BCE research in biochemical process engineering is rapidly developing, future studies should strengthen the theoretical foundations, adopt interdisciplinary approaches, and develop context-sensitive frameworks to enable a more inclusive and sustainable bio-based circular transition.