Techno-economic design and validation of a 70 m3 concrete biodigester for the co-digestion of pig manure and organic waste in a 10 kWe biorefinery

Castillo Alvarez Y.; Pablo Gómez Montoya J. · Proceedings of the LACCEI international Multi-conference for Engineering, Education and Technology (2026) · DOI: 10.18687/laccei2026.1.1.1144

Resumen

Pig farming in the Ventanilla pig park (Callao, Peru) generates large volumes of manure that are currently managed in a precarious manner, with diffuse emissions of methane, leachates, and socio-environmental conflicts in a densely populated peri-urban area. Although biogas utilization offers a sustainable alternative, most of the solutions available to small and medium-sized producers are based on empirical designs, without clear criteria for organic load, hydraulics, or structural safety. This work presents the design and full-scale construction of a cylindrical concrete biodigester as a demonstration module to valorize manure from the Ventanilla pig farm and power a 10 kWe electric generator. The reactor is 5.0 m high and 3.8 m in internal diameter with a hemispherical dome, reaching a total internal volume of approximately 71 m3; of this volume, 70% is used for digestion liquor and 30% for biogas storage. The process sizing is based on a volumetric organic load of 2.5 kgSV/m3·day and a hydraulic retention time of approximately 23 days, considering 65 kg pigs with manure production of 8% of live weight, 6% dry matter, and 95% volatile solids. Under these assumptions, the system is designed to treat the manure of around 420 pigs, with a theoretical production of 43-44 m3/day of biogas (0.35 m3/kgSV) equivalent to about 96 kWh/day of electricity, sufficient to operate the 10 kWe generator for 9-10 hours per day. The civil plant already built and the planned integration of agitation equipment, gas hood, biogas lines, and generator set make this module a replicable demonstration platform for reducing environmental impacts and improving energy security in peri-urban pig farms.

Instituciones: Universidad Tecnológica del Perú