Estimativa da produção de gás metano no aterro sanitário municipal de Vitória da Conquista - BA: um estudo da sua geração e viabilidade econômica

Abstract

The deposition of solid waste in landfills is one of the main forms of management and final disposal of these materials. Landfills are designed and operated accordance with technical criteria and specific standards, aiming to minimize the impacts environmental and public health risks. One of the main challenges associated with the deposition of waste in landfills is the generation of gases, especially methane (CH4). The methane is produced during the anaerobic decomposition process of organic residues present at the landfill. This gas is highly potent in terms of the greenhouse effect and contributes significantly to climate change. To deal with methane generation, landfills implement gas collection systems. Pipes and wells are installed in landfill areas to capture methane and other gases produced. These gases are then channeled to a treatment or recovery system, such as controlled burning to generate energy or conversion into biogas. Methane gas captured in landfills can be directed to power plants, where it is used to drive turbines and generate electricity. This electricity can be used locally or injected into the electrical grid, contributing to the supply of renewable energy. Therefore, based on research made and projected calculations, the Municipal Landfill of Vitória da Conquista – BA has a high methane gas production annually; In its first year of operation, the landfill produced around 36,155,295.14 m3 /year, with an energy power of 5.5 MW, which is equivalent supply 23 thousand inhabitants per year and, in its last year of operation, it will produce 8.49 MW which corresponds to 41,250 people. Thus, the capture for energy use of gas methane from landfills becomes environmentally and socially viable, reducing environmental impacts of emissions into the atmosphere bringing positive effects that affect the quality of the environment and the health of the surrounding population. Regarding viability financial, the total value adopted for the project is R$ 84,372,750.00, for implementation and maintenance. An alternative for calculated revenue is the sale of energy electricity produced which, for the last years of the landfill's useful life, were estimated at R$ 472,707,415 with a tariff of R$ 1.05; R$562,746,923 with fare at R$1.25; R$ 652,786,431 with the fare at R$ 1.45; R$ 742,825,938 with the fare at R$ 1.65 and R$ 832,865,446 with the fare at R$1.85, generating profits of R$388,334,665 respectively; R$ 478,374,173; R$ 568,413,681; R$ 658,453,188 and R$ 748,492,696 so that the city of Vitória da Conquista, as well as other city halls, will adopt the gas capture system originating from landfill, bringing a great financial return. This project fulfills the role of stimulus for the city's next landfill to begin with a collection since the beginning of the operation. A future suggestion would also be a study of the commercialization carbon credits and emission reduction certificates for partner companies.