Avaliação quantitativa do impacto ambiental das emissões gasosas e do uso da água de resfriamento em instalações de geração termelétrica

Abstract

The energy crisis that Brazil faced in the past years has made the country, whose energy matrix is mainly based on water resources, opt for the use of other primary sources of energy in order to fulfill the demand of electricity. Within this scenario, the government has launched the “Priority Thermoelectricity Program” – PPT – aiming at increasing the country’s generating capacity. This program forecast the construction of more than 40 thermal plants using different generation technologies. Thermal generation brings advantages such as the fulfillment of environmental requests, once natural gas, which is used by most of the plants, is less polluting than other fossil fuels. In addition, thermal plants will be installed close to energy consuming centers. Their construction time is shorter and it is easier to obtain financial aid. This study intends to: - Identify the different methods of controlling pollutants that may be released by thermal plants; - Compare typical emissions of different thermal generation technologies with the emission standards in force in Brazil and in other countries; - Per capita vehicle and oil refinery emissions are compared in relation to the emissions coming from the thermoelectricity Brazilian program; - The environmental impact of polluting emissions is also evaluated in the light of a new parameter called Ecological Efficiency; - The impact of environmental conditions regarding water specific consumption for cooling considering different generation technologies, types of towers and the location of the plants is also evaluated. The methodology used to evaluate the gaseous emissions it was through you analyze comparative with the patterns of effective emissions in Brazil and in the world and, the patterns of quality of the air in agreement with the World Organization of the Health. For the use of the water in cooling systems analyzes it was her accomplished through a study of cases using the software Thermoflex. The principal obtained results were: the use of the natural gas and the use of control methods of pollutant reach the effective international patterns and they increase the ecological efficiency. The cogeneration results in discharges ecological efficiencies. Areas with it adapt smaller temperature they consume less amounts of water. And, the use of cooling towers evaporates it reduces the efficiency of power plants, mainly in hotter areas.