A nature-based approach to enhance the potential application of forest residues in anaerobic digestion

Forest residues and other woody wastes are abundant and require management. Anaerobic digestion (AD) is a potential disposal option for such waste, but the absence of cost-effective pretreatment technologies hinders their utilization in AD. This paper presents a nature-based approach for improving AD performance of forest residues, relying on the lignocellulose degradation processes inherent in the forest ecosystem. Wood samples at five decay classes (numbered 1-5 with increasing decay) were collected for series of experiments. Physicochemical analysis showed that higher decay class samples presented a series of characteristics favorable to AD. Wood samples from decay class 1 had the lowest methane yield, while decay class 3 had the highest, with a notable 160 % increase compared to decay class 1. The outcomes identify the stage of highest methane production from forest residues, allowing for strategic collection to improve the economic viability of using forest residues as feedstock for AD applications.