Avaliação técnica e econômica da utilização de biometano proveniente de aterro sanitário da região Sudeste do Brasil para abastecimento veicular

Abstract

Brazil has an underused potential for the generation of biogas and biomethane. Biogas can be used to generate electricity, for heating or, when purified at legislation’s appropriate levels giving rise to biomethane, as a fuel for vehicle supply. Replacing fossil fuels with this type of fuel considerably reduces greenhouse gas (GHG) emissions. Scientific research in this area are essential for the development and expansion of the utilization of this fuel in the country in face of the contributions it brings to environmental quality and to the delay of global warming and climate change, adding also the economic need to find substitute sources for the non-renewable ones. The use of biogas for electricity generation is a more widespread practice in Brazil, however, the use of biomethane as vehicular fuel is a more recent practice and, therefore, less studied. This research proposed to analyze the economic viability of the use of biomethane produced from consortia of existing sanitary landfills in the Southeast Region of Brazil, considering its use as vehicular fuel. A total of 508 cities distributed in 50 consortia of sanitary landfills in the States of São Paulo, Minas Gerais, Espírito Santo and Rio de Janeiro were analyzed. The economic viability was verified using the Net Present Value (NPV) and the Internal Rate of Return (IRR). For comparison purposes, two different forms of calculation were used for the pricing of biomethane sales: the first one considered direct sales to gas stations, while the second considered contract sales to non-thermal markets. For the first pricing methodology, of the 50 consortia studied, seven did not present economic viability for the commercialization of vehicular biomethane. Consortia with an installed capacity of less than 5,500 m³/day were those economically unviable. The relationship between the installed capacity and NPV found is of the linear type, that is, the greater the installed capacity is, the greater the NPV of the projects. However, the IRR of the projects, starting from a CAPEX (Capital Expenditure) of R$ 20 million, remains constant, around 35%, regardless of the increase in CAPEX As for the second pricing methodology, 14 of the consortia did not show economic viability for this purpose, the IRR for this pricing remained constant from a CAPEX of R$ 30 million, around 20%. There was also a reduction in GHG, over the 20 years adopted in this research, with the replacement of the volume of biomethane produced by the landfill consortia for diesel oil: the emission of 29.14 trillion tons of CO2eq is avoided.