Avaliação de resultados e causas do insucesso na geração de créditos de carbono nos Aterros Bandeirantes e Sítio São João

Abstract

One of the gases with higher global warming potential is the methane (CH4) which is 25 times more harmful than carbon dioxide (CO2). The methane emission occurs in various human activities including landfills. Following the ratification of the Kyoto Protocol and the implementation of the Clean Development Mechanism (CDM) by the United Nation Framework Convention on Climate Change (UNFCCC), several projects in landfills were enrolled in this organization. The projects capture the methane that would be emitted to the atmosphere and direct it to power generation or to burning at high temperature. CDM projects should be economically profitable, considering the sale of carbon credits and energy generated. This work aims at studying the case of the two largest CDM projects in landfills in Brazil - Bandeirantes Landfill and Landfill São João, which generate less credits than foreseen variables that may have influenced the differences between the volume of biogas and carbon credits estimated are analyzed. The evolution of estimation methods is also studied. The study’s methodology was a multiple case study in order to make a comparison between the estimated production of biogas and carbon credits and the actual captured in CDM Projects Landfill Bandeirantes and São João Support for the study came from six sources distinct: documents, files, interviews, direct observation, participant observation and physical artifacts. The results indicate that the differences between estimated and actual production can be captured as a result of various factors such as pH, humidity, type of coverage (soil and grass) and the model of institutional arrangement of the studied projects. The conclusion is that the CDM Projects from the Bandeirantes and São João Landfill were overestimated by using a methodology which did not include many parameters that directly interfere with the production of biogas and suffer the financial consequences by not generating electricity and carbon credits. It is suggested that the monitoring of parameters that directly interferes in the biogas production is held jointly by the landfill operator and project proponent in order to facilitate the identification of problems and corrections to do not impair the production and collection of biogas. The research can be applied to new landfills and in operation for sizing equipment/instruments from the collection of biogas and power generation plants, besides informing about the best practices to be made regarding the closure of landfills in operation, as the type of grass and the cover on the top of the landfill. The research also showed that the best methodology for calculating estimated biogas production is more efficient for Brazilian landfills, considering the parameters of the methodology ACM0001 - ver.15.