Desenvolvimento de um inventário de emissões atmosféricas por fontes fixas para o Brasil

Abstract

Atmospheric emissions for major stationary sources of pollutants in Brazil were inventoried and spatially distributed in this work. The developed inventory comprises a total of 16 refining units, 1730 thermoelectric power plants, 96 cement industries and 64 pulp and paper industries. The inventory is to base year 2011 but the data collected vary according to availability, between 2008 and 2015.The inventoried power plants represent about 28% of the electricity generated in Brazil, including as fuel natural gas, sugarcane bagasse, residual fuel oil, diesel oil and coal, representing about 94% of the electricity produced by the sector. For the pulp and paper industrial sector, the inventory comprises over 95% of installed capacity. The limits proposed by the AP-42 standards of the US Environmental Protection Agency – USEPA to the emission factors were applied in the calculations. Additional emission factors identified in the scientific literature were also included in the analysis as parameters for evaluation the range of uncertainty associated with the estimated emissions. The results show values of 857±415 Gg/year for NOx, 1,51±1,23 Tg/year for SOx, 21,2±13,7 Tg/year for CO, 10,4±10,1 Tg/year for MP, 1,14±0,95 Tg/year for TOC and 21,2±13,7 Tg/year for CO2. In comparison with values estimated for vehicles (MMA, 2011), the results show that the total estimated for NOx emissions was slightly lower than emissions from vehicles (944 Gg / year), while for the SOx the emissions were estimated to be more than 300 times vehicular emissions (about 5 Gg / year). For CO the estimated emissions were about 17 times the vehicle emissions, while for PM the estimated values were about 360 times the emissions estimated for vehicles. TOC emissions were about five times the estimated vehicle emissions. The estimated emissions for CO2 were about three times the vehicular emissions. Even when the lower limits of the emission factors are assumed, the contribution by stationary sources are still significant, with NOx being the only pollutant that would be overcome by vehicle emissions. The findings of this study clearly show that atmospheric emissions from stationary sources play a fundamental role in determining the concentration of air pollutants in Brazil. Any numerical scenario designed for air quality studies and to evaluate the impact on health, or even the definition of new policies related to the subject, need to include this new inventory in the scope.