assessment on the environmental effect of adding soybean ethylic biodiesel to fossil diesel for...
TRANSCRIPT
Assessment on the environmental effect of adding
soybean ethylic biodiesel to fossil diesel for
passengers transportation in urban center
Alex R. Nogueira, Luiz Kulay and Gil Anderi da Silva
Passengers’ transportation in Brazil
Cities were designed for vehicles;
Lack of railroads or subway;
Road transportation prevails
large demand for infrastructure;
air pollution due to diesel consumption;
need for alternative fuels.
Biodiesel incorporation to the Brazilian energy matrix
National Program for Biodiesel Production and Consumption;
Federal law 11,097/2005: determined a gradual addition of biodiesel into fossil diesel blends:
at least 2% (B2) from 2008 to 2010;
at least 5% (B5) since 2010;
Mixtures are expressed in terms of biodiesel volumetric percentage.
Biodiesel as an alternative fuel
Biodiesel is traditionally proclaimed as more beneficial than fossil diesel:
better results in terms of Climate Change and energy efficiency; higher cetane number and oxigen content; lower sulfur content and safer storage.
On the other hand, there are some drawbacks associated with biodiesel consumption, such as:
impacts due to feedstock cultivation; poor cold flow properties and oxidation susceptibility;
Comprehensive analysis can be obtained from Life Cycle Assessment (LCA) studies.
well-to-wheel (WTW)
tank-to-wheel (TTW)well-to-tank (WTT)
LCA approaches for fuels
Goal
The study aims at evaluating the environmental effects of
different biodiesel + fossil diesel blends in passengers
locomotion by bus in the metropolitan region of São Paulo
(Brazil), considering the LCA well-to-wheel approach.
Blends considered:B0 (i.e. only diesel);B5B10B20B50
39 cities
20,7 million inhabitants
7,947.3 km2
20% of Brazilian GDP (approx.)
258 km of railroads
78 km of Metro
more than 20 thousand buses
6 million cars
São Paulo metropolitan region
Product system (foreground)
Bioethanol production
Soybean oil production
Transesterification Bus operation
Fossil diesel production in Brazil
Fossil diesel production in other
countries
Blending
T
T
T T
T
T
Scope
Methodological standardization: ISO 14044 (2006);
LCA approach: well-to-wheel;
Functional unit: passengers transportation in urban buses through 100 km;
This study is based on data adapted from Sugawara (2012), Nigro et al. (2008) and Leal (2008);
Geographical coverage: bus operation at São Paulo Metropolian region, and respective feedstock production in Brazil;
Technological coverage: Mercedes-Benz OM 904 LA engines (EURO III). Nevertheless, data can be considered as good proxy for buses operation in the region;
Allocation: economic criterion;
Life Cycle Impact Assessment (LCIA): ReCiPe v. 1.08 – endpoint.
CO2
Engine performance
Engine performance
BLENDDENSITY 15oC
(kg/L)AUTONOMY
(km/L)
FUEL CONSUMPTION
AT BENCH(g-comb/kWh)
CONSUMO DE COMBUSTÍVEL
(L/100km)
Diesel 0,842 2,3767 219,7 42,0751
B5 0,845 2,3767 220,3 42,0751
B10 0,847 2,3624 221,0 42,3291
B20 0,850 2,3482 222,5 42,5862
B50 0,863 2,3315 229,3 42,8901
Engine operation parameters considered in this study.
LCA results
Impact category Bus operation – B 0
Bus operation - B05
Bus operation - B10
Bus operation - B20
Bus operation - B50
Climate change (human health) 7,05E+01 6,87E+01 6,69E+01 6,30E+01 4,68E+01
Climate change (ecosystems) 7,83E+00 7,63E+00 7,43E+00 6,99E+00 5,20E+00
Particulate matter formation 2,11E+01 2,32E+01 2,51E+01 2,95E+01 4,74E+01
Photochemical oxidant formation 1,34E-02 1,46E-02 1,56E-02 1,78E-02 2,65E-02
Terrestrial acidification 2,49E-02 2,75E-02 2,99E-02 3,55E-02 5,84E-02
Human toxicity 5,75E-02 6,09E-02 6,46E-02 7,30E-02 1,07E-01
Terrestrial ecotoxicity 6,04E-04 6,53E-04 7,08E-04 8,34E-04 1,38E-03
Freshwater ecotoxicity 2,73E-06 3,74E-06 4,89E-06 7,60E-06 2,06E-05
Freshwater eutrophication 1,71E-05 2,31E-05 2,99E-05 4,62E-05 1,24E-04
Agricultural land occupation 3,70E-05 6,85E-05 1,04E-04 1,89E-04 6,03E-04
Fossil depletion 4,48E-01 4,52E-01 4,57E-01 4,63E-01 4,37E-01
LCA results
Impact categories contribution to the single score indicator (Pt).
B5/B0 B10/B0 B20/B0 B50/B0
Climate change Human Health 0,917 0,844 0,701 0,350
Climate change Ecosystems 0,917 0,844 0,701 0,350
Particulate matter formation 1,033 1,055 1,095 1,182
Photochemical oxidant formation 1,024 1,033 1,046 1,045
Terrestrial acidification 1,040 1,068 1,119 1,235
Human toxicity 0,997 0,998 0,996 0,981
Terrestrial ecotoxicity 1,018 1,042 1,084 1,202
Freshwater ecotoxicity 1,290 1,589 2,184 3,974
Freshwater eutrophication 1,275 1,559 2,124 3,821
Agricultural land occupation 1,743 2,499 4,015 8,585
Fossil depletion 0,951 0,906 0,811 0,514
TOTAL (single score) 0,942 0,889 0,785 0,527
LCA results
Effect of biodiesel addition to fossil diesel on indicators results for the impact categories.
Conclusion
Increase in biodiesel concentration lead to better environmental results (single score);
However, impacts are dominated by Climate Change results;
Bus operation dominated the impact categories indicator for climate change, particulate matter formation, photochemical oxidant formation and terrestrial acidification;
Fossil fuel depletion seemed to be of little significance to the overall results.
