Life Cycle Assessment of Technologies for Greenhouse Gas Emissions Reduction in Sugarcane Biorefineries

Since sugarcane biorefineries are a large source of CO2 emissions, there is an opportunity of using or capturing this pollutant. An alternative would be to use mechanisms to capture, transport and inject CO2 into underground geological formations with the purpose of permanent storage of this gas, the so called Carbon Capture and Storage or CCS. Another possibility is to produce biodiesel from microalgae cultivated with CO2 to replace fossil diesel used in the sugarcane production chain. Environmental impacts using life cycle assessment of both technologies, CCS and biodiesel production from microalgae, integrated into first and second generation ethanol production plants were assessed. Biodiesel production from microalgae promoted reduction in all the assessed environmental impact categories, decreasing about 35 % of climate change impacts. CCS presented the highest climate change reduction transforming ethanol in a net carbon absorber. However, higher environmental impact in other categories are observed in this case.