Contribuição ambiental para o planejamento da oferta futura de gás natural no Brasil.

Abstract

During the last three decades, the natural gas field has shown considerable progress as its participation in the Brazilian energy matrix. This growth is related to the supply and demand as well as the potential of lower environmental impact compared to other fossil fuels. Therefore, considering these characteristics, the Natural Gas became one of the main sources of energy. Beside the technical and economic benefits of the natural gas, it has also become a strategic source of energy, mainly due to the smaller impacts that are provided when compared to Oil and its derivatives. In view of this situation, Brazil has expanded and making available this resource due to the discovery of new reserves in São Paulo and the Northeast Coast. However, the scenario of the pipeline transport infrastructure is different. The country's current refined gas distribution network is not serving a significant portion of the residential population in the North, Midwest and even important counties in the countryside of the Northeast and Southeast.Therefore, it was sought to determine, for the current situation, the benefits and the overall environmental impact of the Natural Gas supply and to evaluate the future condition for this input. For this, it was decided to adopt the Cycle Assessment of Life (ACV) which is an environmental management tool used to evaluate environmental impacts associated with products, processes and services. Its main characteristic is to evaluate in a systemic way, taking into account all stages of its life cycle. The goal of this work was to evaluate the environmental contribution to the planning of the future supply of the natural gas in Brazil, according to the life cycle approach. For the environmental analysis, it was used the Life Cycle Impact Assessment (AICV), Recipe midpoint and, for energy analysis, the Primary Energy Demand method was used, followed by the calculation of the Energy Return on Investment Index (EROI). The results in terms of the environmental profile indicated that the processes that most contributed to the GHG emissions are the extraction and processing of the raw gas in the Gas Processing Units (UPGNs). The main contributions to Climate Change are CH4 emissions, which occur during the transportation of the raw or finished gas. For the South and Center-West, it was observed the influence of CO2 losses, which occur in the compression stations that move the gas from Bolivia to the South and Center-West areas of the country. In terms of PED, the results indicate a concentration of consumptions as NRF. It can be observed that the most of the losses of CH4, with great relevance, occur in the extraction of the input during the withdrawal of the fossil resource from the reserves. For the future supply condition the analysis showed that, for PED, the transport distance is a decisive factor, even supplanting the volume of refined gas to be distributed for the impact profile. Regarding CC, these two parameters will be important, and the greatest impact weight will be on the amount of gas distri...