Exploring biorefinery alternatives for biowaste valorization: a techno-economic assessment of enzymatic hydrolysis coupled with anaerobic digestion or solid-state fermentation for high-value bioproducts
Creators: name: Molina-Peñate, Esther
name: Artola, Adriana
name: Sánchez, Antoni
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Biochemistry
subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Biological Sciences not elsewhere classified
subject: Science Policy

description: Enzymatic hydrolysis of organic waste is gaining relevance as a complementary technology to conventional biological treatments. Moreover, biorefineries are emerging as a sustainable scenario to integrate waste valorization and high-value bioproducts production. However, their application on municipal solid waste is still limited. This study systematically evaluates the techno-economic feasibility of the conversion of the organic fraction of municipal solid waste (OFMSW) into high-value bioproducts through enzymatic hydrolysis. Two key variables are examined: (a) the source of the enzymes: commercial or on-site produced using OFMSW, and (b) the treatment of the solid hydrolyzate fraction: solid-state fermentation (SSF) for the production of biopesticides or anaerobic digestion for the production of energy. As a result, four different biorefinery scenarios are generated and compared in terms of profitability. Results showed that the most profitable scenario was to produce enzymes on-site and valorize the solid fraction via SSF, with an internal rate of return of 13%. This scenario led to higher profit margins (74%) and a reduced payback time (6 years), in contrast with commercial enzymes that led to an unprofitable biorefinery. Also, the simultaneous production of higher-value bioproducts and energy reduced the economic dependence of OFMSW treatment on policy instruments while remaining energetically self-sufficient. The profitability of the biorefinery scenarios evaluated was heavily dependent on the enzyme price and the efficiency of the anaerobic digestion process, highlighting the importance of cost-efficient enzyme production alternatives and high-quality OFMSW. This paper contributes to understanding the potential role of enzymes in future OFMSW biorefineries and offers economical insights on different configurations. Techno-economic analysis to assess enzyme origin and solid hydrolysate fate.The viability of enzymatic hydrolysis depends on the cost and origin of enzymes.On-site produced enzymes cut payback time to 6 years, elevating profits by 74%.Anaerobic digestion and solid-state fermentation can be complementary technologies.High-value bioproducts are key to making organic waste biorefineries profitable. Techno-economic analysis to assess enzyme origin and solid hydrolysate fate. The viability of enzymatic hydrolysis depends on the cost and origin of enzymes. On-site produced enzymes cut payback time to 6 years, elevating profits by 74%. Anaerobic digestion and solid-state fermentation can be complementary technologies. High-value bioproducts are key to making organic waste biorefineries profitable.