Cattle manure biochar as an additive to improve methane production from cheese whey in rural areas

Madrigal G.; Mamani-Cachicatari G.; Mendieta O.; Martí-Herrero J. · Renewable Energy (2026) · DOI: 10.1016/j.renene.2026.126077

Resumen

Cheese production in the Puno region generates cheese whey (CW) as an organic waste while requiring substantial energy inputs, making anaerobic digestion (AD) a promising solution. Unlike previous studies focused on single-substrate systems, this study evaluated AD integration using CW from five cheese factories, with and without manure-derived biochar (BM-BC). CW mono-digestion showed rapid acid accumulation and methanogenesis inhibition (13.57–50.48 mL CH4 g−1 VS). In contrast, BM-BC addition significantly increased methane yields to 270.94–352.08 mL CH4 g−1 VS. BM-BC stabilized digestion through volatile fatty acid buffering, promoted microbial growth, and increased methane concentration to 63.4% v/v. Energy integration analysis showed that two factories could fully replace conventional fuels with biogas, while the others achieved approximately 80% substitution. Economic assessments indicated annual savings of USD 1885.0–6074.6 and payback periods of 1.6–5 years. Additionally, GHG emission offsets averaged 15.5 t CO2-eq yr−1 across the evaluated factories. These findings demonstrate the technical, economic, and environmental viability of BM-BC-enhanced AD in the regional cheese industry, supporting renewable energy development and sustainability goals.

Instituciones: Universidad Peruana Unión