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Abstract: While biofuels have currently been regarded as a good alternative for fossil fuels, there remain many debates on their impacts on human and environment. This paper tried to shed light on bio-ethanol in Brazil as one of the main producers and exporters in the world. The main question was to understand “how sustainable is bio-ethanol production in Brazil?” To answer, the political motives of producing bio-ethanol followed by its ecological and socio-economic impacts were discussed. The paper concluded that although bio-ethanol production in Brazil seems environmentally friendly, it might socio-economically be hazardous. [Copyright &y& Elsevier]

The potential for sugarcane ethanol from Brazil to mitigate GHG emissions is undeniable, but the way that ethanol is produced during the agricultural and industrial phases will ultimately determine its benefits to society. In this paper, we evaluate the environmental impacts of sugarcane agriculture and ethanol production in Brazil as management practices continue to change and production expands to new frontiers. We focused our evaluation on the impacts on water, atmosphere, and soils, including how the application of organic and inorganic fertilizers and the accumulation of crop residue in the field affect emissions of greenhouse gases (GHG). We also addressed the impacts of land use changes on threatened biomes and discussed some of the present obstacles regarding conservation and restoration efforts. We concluded that, since a similar assessment was put forth in 2008, our knowledge about the environmental impacts of sugarcane ethanol in Brazil has advanced with regard to soil degradation, nitrogen dynamics, and soil carbon stocks. However, more information is still needed about the impacts of the increasing use of pesticides, herbicides, and fertilizers in sugarcane agriculture, especially on water resources. Furthermore, without a better understanding about how landscape fragmentation affects the biodiversity of terrestrial and aquatic tropical ecosystems and the services they provide, policies created to protect and restore them may be ineffective. On the other hand, the use of presently available scientific information to end unsustainable farming and the implementation of conservation strategies proposed by the Brazilian Forest Code could be a first step to guarantee that ethanol is produced more sustainably in Brazil. [ABSTRACT FROM AUTHOR]

This paper presents the potential of biogas from anaerobic digestion of vinasse and its impact in different contexts. The use of vinasse biogas (VBG) for power generation is evaluated and the potential of this energy source is compared with fossil oil power plants in terms of energy, costs and greenhouse gases (GHG) emissions in Brazil, suggesting a program where the most expensive oil power plants are replaced by biogas plants with benefits in all aspects. Secondly, the use of vinasse biomethane (VBM) to replace natural gas (NG) in the state of São Paulo is examined, presenting an incentive program that could make this alternative fuel feasible even in smaller scale plants with minimal impact on NG costs in this state, while providing considerable emission reduction. The impact of VBG considering the increase in ethanol production over the next ten years is also evaluated, showing that substantial additional energy can be obtained and larger amounts of fossil fuels can be replaced. By crossing vinasse biogas potential with selected fossil fuels demand, the article brings insights to help the transition to a low-carbon society in a novel approach. The conclusions are that VBG and VBM can provide great benefits, such as USD 1 billion/year cost reductions and 6.7 million tons CO 2e /year emissions avoided by replacing fossil oil by biogas in power generation in Brazil and 3.2 million tons CO 2e /year avoided with biomethane replacing natural gas in the state of São Paulo, which, with specific programs and policies, could be achieved. • Vinasse biogas could replace fossil oil and natural gas in Brazil. • Electricity from vinasse biogas avoid GHG emissions at lower costs than oil plants. • Vinasse biomethane can replace natural gas in São Paulo with minimal cost increase. • Vinasse biogas can substitute more fossil fuels with increased ethanol production. [ABSTRACT FROM AUTHOR]