ebi, september 24, 2010. (epa, 2010) (eia, 2010)
TRANSCRIPT
Emerging Environmental Challenges for Biofuels Production
Elliott Campbell University of California, Merced
EBI, September 24, 2010
Liquid Biofuel
(EPA, 2010)
Biopower
(EIA, 2010)
Why Bioenergy?
Similarities to current energy system Near-term Cost effective Scalable Deployable/storable Carbon-negative potential Rural economic development Appropriate technology options for the
developing world Synergies with fossil fuels Synergies with other renewables Perhaps better to ask “How?”
Roadmap
1. Air Quality2. Short-Lived Climate Forcers3. Land-Use Efficiency
1) Air Quality
Vehicle Phase Emissions
Ozone increase in LA and northeast offset by decrease in southeast
E85 unlikely to improve air quality Emissions outside of vehicle phase neglected
(Jacobson, ES&T, 2007)
Life-Cycle Emissions
Human health costs ~ Climate change costs Importance of upstream emissions relative to
vehicle emissions
(Hill et al., PNAS, 2007)
Sugarcane Ethanol Emissions
0
100
200
300
400
500
600
700
800
900
NOx VOC SOx CO
Life
-cyc
le E
mis
sion
(g e
mitt
ed /
mm
Btu
fuel
)
Sugarcane Ethanol
Corn Ethanol
Importance of Open Burning
VOC NOx PM10 PM2.5 SOx CO
Em
issi
on F
acto
r (g
em
itted
/ mm
Btu
)
0
1000
2000
3000
7000Straw Field Burning Straw Field Burning (50% Area Burned) Other Farming Ethanol Refinery Ethanol T/D Vehicle Use
Emissions Currently Underpredicted
1. Create a market for sugarcane trash2. Emissions from indirect land-use
change
Relation to Next-Generation Biofuels
(Morton et al., GCB, 2008)
2) Short-Lived Climate Forcers
Aerosols and Ozone Atmospheric lifetimes of days to
weeks Cooling and warming properties Spatial-explicit climate impacts Black Carbon has 55% of the RF
caused by CO2 and a greater forcing than all other SLCFs (Ramanathan and Carmichael, 2008)
Short Live Climate Forcers (SLCFs)
(Unger et al., PNAS, 2008)
0
10
20
30
40
50
60
70
80
90
100
Gasoline Sugarcane Sugarcane + BC_low
Sugarcane + BC_high
Clim
ate
Forc
ing
(g C
O2-
e /
MJ
fuel
)
Need for a Regional Analysis
(Naik et al., GRL, 2007)
3) Land-Use Efficiency
19
Global Land Use
(Campbell et al., ES&T, 2008)
20
County-Level Abandoned Agriculture
0
200
400
600
800
1,000
1,200
Aban
done
d Ar
eas (
1000
km
2 )
County crop
HYDE crop high
HYDE crop low
SAGE crop
HYDE pasture high
HYDE pasture low
(Campbell et al., in prep)
Regional Land Use
(Debolt, Campbell, et al., GCB-Bioenergy, 2010)
Source for stratospheric sulfate aerosol.
Important role in stratospheric ozone.
A novel tracer of terrestrial photosynthesis?CO2 COS
Fig. 1. The dominant land fluxes of CO2 are photosynthesis and respiration while OCS uptake is influenced by a process linked to photosynthesis.
Carbonyl Sulfide (COS, OCS, CSO)
Vertical Profiles
(Campbell et al., Science, 2008)
Energy Conversion Pathways
25
0
10,000
20,000
30,000
40,000
50,000
Gro
ss E
lect
ricity
Out
put
Fuel
Cyc
le E
lect
ric I
nput
Fuel
Cyc
le G
asol
ine
Inpu
t
Veh
icle
Cyc
le E
lect
ric I
nput
Veh
icle
Cyc
le G
asol
ine
Inpu
t
Net
Out
put
0
10
20
30
40
50
Gro
ss E
than
ol O
utpu
t
Fuel
Cyc
le E
lect
ric I
nput
Fuel
Cyc
le G
asol
ine
Inpu
t
Veh
icle
Cyc
le E
lect
ric I
nput
Veh
icle
Cyc
le G
asol
ine
Inpu
t
Net
Out
put
Tra
nspo
rtat
ion
Mil
eage
(10
3m
i ha
-1y-1
)
a) Ethanol b) Bioelectricity
(Campbell, Lobell, & Field, Science, 2009)
Transportation per Cropland Area
Conversion Pathways
Advantages to expanding focus to include electricity in addition to liquid fuels
Greater emphasis on jet and tanker fuels
Lignin rich feedstock
Questions for Emerging Issues Win-win solutions where environmental
mitigation results in more bioenergy supply? E.g. Sugarcane burning vs. second-
generation fuels SLCFs incorporated in mandated GHG
thresholds? International leakage of air quality
impacts? Abandoned lands and other alternative
land resources?