Assessing total and renewable energy in Brazilian automotive fuels. A life cycle inventory (LCI) approach

This article uses a first approach LCI procedure to evaluate total and renewable energy and CO2 emissions in Brazilian automotive fuels life cycle (LC). The LC model is structured and modular, capable of being successively refined if necessary. The procedure is applied to passenger car use in urban traffic, comparing three fuels used in Brazil (gasoline with 25% ethanol, pure ethanol and compressed natural gas), considering their use in urban traffic in the city of Rio de Janeiro. An in deep research was made to collect representative and unpublished data of Brazilian automotive fuels LC reality, what is considered a main contribution. The results show where specific advantages occur, particularly in the use of renewable fuels made from biomass, an option already practiced and appropriate for Brazilian reality. The use of gasoline with 25% ethanol shows the lowest total energy consumption for the LC, with similar performance to that of compressed natural gas and 36% better than ethanol from sugarcane. However, the last alternative has the advantage of depending almost exclusively on renewable energy (93%) and producing less net CO2 emissions.