Study of the anaerobic co-digestion of bovine and swine manure: Technical and economic feasibility analysis

Abstract

This study seeks to theoretically evaluate electrical energy generation from biogas using a co-digestion process of both bovine and swine manure in anaerobic biodigesters. The analysis was performed using theoretical data from literature on daily animal manure output where the best quantitative methane generation was 4 parts bovine manure to 1 part swine manure. After the analysis of the substrate's biogas production, a technical and economic feasibility study was carried out using Net Present Value (NPV), the Internal Rate of Return (IRR), and the Levelized Cost of Energy (LCOE) investment projection tools. We also mapped the co-digestion potential and the offset of Greenhouse Gases (GHG) emissions associated with this application. The results showed that biogas plant projects using manure co-digestion processes are viable, starting at 1410 heads of cattle and 2350 head of swine. This quantity waste proportion results in a methane flow of 163.41 m³∙d−1, corresponding to an energy potential of 128 MWh∙year−1, thus placing the enterprise within the distributed microgeneration categorization, according to resolutions No. 482/2012 and No. 687/2015 from the National Electric Energy Agency (ANEEL).