Biochar Enhances Anaerobic Co-Digestion of Poultry Litter and Wheat Straw

A study showed that adding alkaline biochar to anaerobic co-digestion of poultry litter and wheat straw boosts methane yield by 9.7%, improves solid removal, and enhances beneficial microorganisms. Optimal conditions included a specific carbon-to-nitrogen ratio and biochar dosage, significantly enhancing waste management efficiency.

July 9, 2024

1–2 minutes

Zhan, et al (2024)
BiocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More enhanced anaerobic co-digestion of poultry litter and wheat straw: performance, microbial analysis, and multiple factors’ interaction. *Renewable Energy*. https://doi.org/10.1016/j.renene.2024.120907

A recent study explored the use of biochar to enhance anaerobic co-digestion (Co-AD) of poultry litter (PL) and wheat straw (WS). This method converts agricultural waste into methane-rich biogas, offering an eco-friendly solution to waste management. Conducted in two phases, the study assessed the impact of adding alkaline biochar (ABC) on methane yield and the efficiency of the Co-AD process.

The feasibility experiment revealed notable improvements with biochar addition: a 9.7% increase in cumulative methane yield, a 15.2% rise in total solids removal, and a 14.2% increase in volatile solids removal. Biochar also boosted the presence of beneficial microorganisms like Methanobacterium and Methanosaeta, enhancing the methanogenic pathways by 37.3% compared to the control group.

In the interaction experiment, researchers discovered that the biochar dosage interacted significantly with the initial carbon-to-nitrogen (C/N) ratio and total solids (TS) level of the substrate. Mathematical models predicted optimal conditions for maximizing methane yield and solid removal: a C/N ratio of 29.93, TS level of 6.98%, and biochar dosage of 9.98% of the substrate. Under these conditions, methane yield and solid removal rates were 17.7% and 22.1% higher, respectively, than the control.

These findings demonstrate that biochar can significantly enhance the Co-AD process of agricultural wastes, providing a sustainable method for improving methane production and waste management.