title: Assessing GHG emissions, ecological footprint, and water linkage for different fuels.
abstract: Currently, transport is highly dependent on fossil fuels and responsible for about 23% of world energy-related GHG (greenhouse gas) emissions. Ethanol from sugar cane and corn emerges as an alternative for gasoline in order to mitigate GHG emissions. Additionally, deeper offshore drilling projects such as in the Brazilian Pre-Salt reservoirs and mining projects of nonconventional sources like Tar Sands in Canada could be a solution for supplying demand of fossil fuels in the short and midterm. Based on updated literature, this paper presents an assessment of GHG emissions for four different fuels: ethanol from sugar cane and from corn and gasoline from conventional crude oil and from tar sands. An Ecological Footprint analysis is also presented, which shows that ethanol from sugar cane has the lowest GHG emissions and requires the lowest biocapacity per unit of energy produced among these fuels. Finally, an analysis using the Embodied Water concept is made with the introduction of a new concept, the "CO(2)-Water", to illustrate the impacts of releasing carbon from underground to atmosphere and of the water needed to sequestrate it over the life cycle of the assessed fuels. Using this method resulted that gasoline from fossil fuels would indirectly "require" on average as much water as ethanol from sugar cane per unit of fuel energy produced.
authors.affiliation: Mechanical Engineering Faculty, University of Campinas, PO Box 6122, 13083-970, Campinas, SP, Brazil. juanfrancisccr@yahoo.com
authors.forename: Mauro F
authors.initials: MF
authors.lastname: Chavez-Rodriguez
authors.forename: Silvia A
authors.initials: SA
authors.lastname: Nebra
mesh_terms: D000397:Air Pollution / Q000032:analysis / Q000517:prevention & control / Q000706:statistics & numerical data*; D056804:Biofuels; D002245:Carbon Dioxide / Q000032:analysis / Q000737:chemistry; D058572:Carbon Footprint / Q000706:statistics & numerical data*; D003247:Conservation of Natural Resources; D004736:Energy-Generating Resources / Q000706:statistics & numerical data*; D004777:Environment; D000431:Ethanol; D005579:Fossil Fuels; D017752:Greenhouse Effect; D014867:Water / Q000032:analysis / Q000737:chemistry
chemical_list: D056804:Biofuels; D005579:Fossil Fuels; D014867:Water; D002245:Carbon Dioxide; D000431:Ethanol