Análise da Qualidade dos Combustíveis de Postos de Abastecimento nos Municípios de Bragança e Tracuateua, Pará

In recent years in Brazil, the media have reported cases of adulteration of fuels at gas stations. In this work, a physical-chemical study was carried out through the tests of anhydrous ethyl alcohol content in samples of common and additive gasoline and the test of the specific mass at a temperature of 20 oC in samples of diesel oil, common gasoline and additive gasoline, to verify the fuel quality at gas stations in the cities of Bragança and Tracuateua (northeastern extreme of the Brazilian state of Pará). When the fuel does not meet current specifications, it is considered non-conformity fuel. Adulteration is related to the addition of products to the fuel that will be marketed and whose objective is to obtain some financial advantage. In the geographic region of Bragança, several users have reported irregular fuels sold at the main gas stations. In this region, due to the lack of studies of this type, analyzes of fuel samples were carried out. The collections were carried out during the 2018-2019 biennium. In total, 58 fuel samples (91.38% in Bragança and 8.62% in Tracuateua) were collected: 36.20%, regular gasoline; 29.31%, gasoline with additives; and 34.49%, diesel fuel. In Bragança, 26.47% of the gasoline samples collected in this city did not have the amount of ethanol as established by law and, therefore, were in non-conformity. In Tracuateua, 75% of the gasoline samples collected also showed the same behavior in relation to the amount of ethanol. In the case of the density at 20 o C allowed by the Brazilian legislation, the city of Bragança presented 11.76% of the gasoline samples collected below the allowed value and were considered as in non-conformity. In the case of Tracuateua, 50% of the gasoline samples collected in this city showed the same behavior in terms of density and were also in non-conformity. For both studied cities, the sole fuel that did not change its specific mass was the diesel one. Therefore, this study revealed the existence of gas stations that have sold regular and additive gasoline outside the permitted standards. This pioneering study is of great importance because it will alert local authorities about the problem of marketing fuels that do not meet the current specifications of the Brazilian legislation and whose emission of gases causes atmospheric pollution besides being harmful to life and to the environment.