Work

Integrated co-digestion of sugarcane by-products for synergistic methane production, energy recovery, and GHG mitigation

Year: 2026

Type: article

Abstract: Efficient co-digestion of sugarcane by-products requires optimization of substrate interactions to maximize methane production while avoiding inhibitory conditions. Previous studies lack a systematic framework to evaluate interactions and determine optimal feed ratios for stable anaerobic digestion. To address this gap, this study employs a D -optimal mixture design to investigate co-digestion performance of filter cake, molasses, and vinasse. Biomethane potential was assessed through mesophilic batch experiments using 60 g VS per mixture, and kinetic modeling was applied to characterize methane production. The mixture containing 5:15:40 g VS of filter cake, molasses, and vinasse produced the highest methane yield of 570 mL CH 4 g −1 VS, while response surface modeling identified 6.42:15:38.57 as the optimal substrate proportion. Molasses acted as the primary enhancer of methane yield, filter cake imposed hydrolytic limitations, and moderate vinasse loading generated synergistic improvements. Synergy index values confirmed positive interactions, particularly in mixtures with higher methane recovery. Based on a reference system processing 1 ton of VS per day, methane from the optimized co-digestion mixtures enabled substantial energy recovery via a combined heat and power system, generating 2.05 MWh day −1 of electricity and 7.49 GJ day −1 of thermal energy. Substitution of grid electricity and natural gas-derived heat corresponded to an estimated 1.58 t CO 2 -eq day −1 of avoided emissions, demonstrating dual benefits of energy production and climate mitigation. Overall, this study presents a data-driven framework for optimizing ternary co-digestion, emphasizing substrate synergy in enhancing methane yield, energy recovery, and greenhouse gas mitigation within a sugarcane biorefinery context.

Source: Industrial Crops and Products

DOI: 10.1016/j.indcrop.2026.124258

Authors: Haniyeh Samadi, Barat Ghobadian, Hossein Ghanavati

Institutions: Tarbiat Modares University, Agricultural Research & Education Organization, Agricultural Biotechnology Research Institute of Iran

Language: English

Topic: Anaerobic Digestion and Biogas Production

Subfield: Building and Construction

Field: Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Responsible consumption and production, Climate action

Open Access status: gold

Estimated APC paid: $3,720