Análise de ciclo de vida (ACV) de óleos refrigerantes para transformadores: comparação entre óleo mineral e óleo vegetal

Abstract

Transformers are considered one of the most important components in the transmission and distribution of the system sector electrical. As they work at high temperature your cooling system must work very well to increase its useful life. Carring out this refrigeration, most systems use mineral oil. The others use vegetable oil. The goal of this work is to carry out a life cycle analysis (LCA) so that it can be check which of the oils have the lowest environmental impacts. For this comparison, the most commonly used mineral oil (which is naphthalene base oil) and vegetable oil (sunflower and soybean oil) will be used. Thus, three scenarios were created to distinguish these most used forms to be used in transformers. In the scenario 1, there is mineral oil. I n scenario 2, sunflower oil and in scenario 3, soybean oil. All inventories collected were plotted to the SimaPro software so that the proposed results could be reached. When comparing these three scenarios, it was found that the best option for lubricating and cooling a transformer is scenario 1, for environmental reasons, to be the best option proposed for this activity. Such response is due to the fact that this scenario presents the lowest values of environmental impacts for air, water and soil. In comparison, scenario 1 only presents the impact of fossil depletion greater than others scenarios, due to the use of oil for its production. The worst scenario for cooling and lubricating transformers is scenario 2, because it presents fifteen values of impacts greater than others scenarios, such as: climate change, occupation of agricultural land and water depletion. The intermediate scenario, presenting two values of impacts greater than others scenarios and still having a negative impact (depletion of water). The quotation served as an assistance to verify which oil has a lower production cost. The cost of liters of lubricating mineral oil is R$1576.6 real per transformer and the cost of liters of lubricating vegetable oil is R$1653.6 real per transformers. We can conclude, based on costs, that mineral lubricating oils have a lower production cost than vegetable lubricating oil.