Quantification and spatial distribution of the bioenergetic potential from slaughterhouses effluents biogas generation across Brazil

Abstract

This study describes the estimation of biogas energy use from the anaerobic treatment system of cattle, swine, and poultry slaughter units in Brazil. The simulation includes spatial distribution of the results and geographical comparison with other energy matrices and clean sources of electricity generation. The paper is divided into four sections: 1) the database formation, which included a survey and geocoding of cattle, swine and poultry slaughter units across the country; 2) a literature review covering the period from 2000 to 2020 to obtain the average Chemical Oxygen Demand (COD) for each of the effluents; 3) a simulation of electricity generation in the slaughter units, according to their classes and origins; and, 4) the preparation of national distribution maps of slaughter units, national bioenergy potential, by state and by animal origin, comparison maps of Electric Slaughter Units (ESU) using hydroelectric, photovoltaic and wind power plants, as well as the comparison map between the biomass energy use (biogas, sugarcane bagasse and black liquor). The slaughter units bioenergetic potential presented on the maps that the density in the distribution of these units adopts the effluent treatment proposal. Moreover, biogas is considered a decentralized energy matrix, but the density of slaughter units within the work proposal opposes this concept. The results indicated the formation of a corridor with a high potential for electricity generation, coinciding with regions that experience electrical stress in Brazil. In numbers, the potential would be enough to supply a population of up to 900,000 inhabitants, emphasizing ESU as a potential alternative for electricity using biogas. This is because the Brazilian meat market is somewhat consolidated, important worldwide and continuously generates effluents, which can add up to 28% to electricity from biomass. The greatest bioenergy potential was obtained in the Midwest region (1792 MW), followed by the South (1486 MW), Southeast (1278 MW), North (923 MW) and Northeast (236 MW) regions of the country. In terms of clean energy, when comparing the distribution of slaughter units with photovoltaic, wind and hydroelectric plants, a large territorial gain is observed (more uniform distribution in the country) and in relation to the electrical use of biomass, biogas use from ESU would promote it as the second largest matrix representing about 31% of national energy.