Life Cycle Assessment of vinasse biogas production in sugarcane biorefineries

The sugarcane biorefinery generates large amounts of vinasse. One strategy is to use this by-product as feedstock for energy production, since it is possible to obtain biogas and provide a better bio-fertilizer for fertirrigation. This paper investigates enviromnental aspects of biogas production and use in different biorefinery configurations. Life Cycle Assessment (LCA) is a tool for quantifying the potential environmental impacts of products, processes, or services, to support the selection making of desire products and/or processes from different alternatives. This work applies the LCA approach using the software SimaPro (R) and CML Baseline 2000 methods. LCA analyses were performed considering biogas production from vinasse in different biorefinery configurations and two on-site applications: as a complementary fuel in the boiler and as a diesel replacement in the agricultural operations. In all scenarios, significant improvements in the environmental impact categories Were observed when biogas was used as diesel replacement. The use of biogas as a complementary fuel in a boiler showed a smooth decrease in the enviromnental impacts compared to the conventional process. The integrated first and second ethanol configurations presented the better results for most of environmental impacts categories compared to the first ethanol configurations. The results indicate that the use of biogas is a promising technology. Its production and use is responsible for improving the productivity and environmental impacts of the plant.