Bioenergy – Carbon Neutral or Not?
Elaine Oneil PhD
Executive Director, CORRIM
Alaska Wood Energy Conference
Ketchikan, AK
October 10, 2012
Consortium for Research on Renewable Industrial
Materials
A non-profit corporation formed by 17 research institutions to conduct
cradle to grave environmental studies of wood products
Type Inherent
carbon
neutrality Carboncycle
neutrality Life-cycle
neutrality Offset
neutrality Definition Biomass carbon was only recently removed from
atmosphere; returning it to the atmosphere merely closes
cycle. If uptake of carbon (in CO2) by plants over given area
and time is equal to emissions of biogenic carbon
attributable to that area, biomass removed from area is
carbon-cycle neutral. If emissions of all greenhouse gases from life cycle of
product system are equal to transfers of CO2 from
atmosphere into that product system, product system is
life-cycle neutral. If emissions of greenhouse gases are compensated for by
using offsets representing removals that occur outside of
product system, that product or product system is offset
neutral. Substitution If emissions associated with life cycle of product are
neutrality equal to (or less than) those associated with likely
substitute products, that product or product system is (at
least) substitution neutral. Accounting If emissions of biogenic CO2 are assigned emissions factor
neutrality of zero because net emissions of biogenic carbon are
determined by calculating changes in stocks of stored
carbon, biogenic CO2 is accounting neutral. Example All biomass is “inherently carbon neutral.” Biomass harvested from regions where forest carbon
stocks are stable is “carbon-cycle neutral.” Wood products that store atmospheric carbon in
long-term and permanent storage equal to (or
greater than) life-cycle emissions associated with
products are (at least) “life-cycle neutral.” Airline travel by passengers who purchase offset
credits equal to emissions associated with their
travels is “offset neutral.” Forest-based biomass energy system whose life-cycle
emissions are equal to (or less than) those
associated with likely substitute systems is (at least)
“substitution neutral.” U.S. government calculates transfers of biogenic
carbon to atmosphere by calculating annual changes
in stocks of carbon stored in forests and forest
products; emissions of CO2 from biomass combustion
are not counted as emissions from energy sector nor
are emissions from decay of dead trees in the forest
counted as emissions in the forest sector. Source: NCASI (2011); used with permission in SAF Task Force Report
Society of
American
Foresters
Climate
Change and
Biomass
Energy Task
Force Report
Annual Flux (Pg C/yr)
8
4
1960
Source:
adapted from Woods Hole Research Center
2005
US forest growth, removals, and mortality
by region, 1953-2006
SE
PNW
Source: Smith et al. 2009
Forests as carbon storage or fossil fuel
offset – which provides the largest
benefit?
$$$
Ocean
Land
Atmosphere
Fossil
Fuel
Reserves
Building
products
Forests
$
Fuels
Long
lived
electricity
Short
lived
Liquid
fuel
EPA Scientific Advisory Panel
US Life
Cycle
Assessment
Tool
Power Plant Feedstocks
Bituminous Coal
Natural Gas
Biomass
Net Biomass (Emissions -­‐ Uptake)
0.
20.
40.
60.
80.
100.
Percentage Emissions Relative to Bitiminous Coal
Source: Lippke et al 2011
Specific Impacts - EISA 2007
•  Mandates renewable fuel targets by 2022
•  Sets GHG thresholds compared to a gasoline
and diesel used in 2005
•  Must conduct a lifecycle analysis to determine
whether or not renewable fuels meet the GHG
thresholds •  Pyrolysis
Liquid Fuels Research
Forest residuals, whole tree, or thinnings
Pyrolysis Oil vs RFO
•  Gasification
Forest residuals or thinnings
Ethanol vs Gasoline
•  Bioconversion
Short Rotation Woody Crops (SRWC)
Biomass Feedstock Substitution at the Mill or Utility
Impacts C-efficiency not energy independence
Boiler
Forest Residuals
Heat for
Drying
Wood
Mill Residuals
Lumber mill
Forest Residuals
or Pellets
Cogen
Avoiding
purchased
electricity
Lumber mill
Global Warming Potential (GWP)
Biochem Ethanol vs gasoline
More than 100%
reduction in
fossil emissions
Sustainable Carbon Mitigation & Increasing Energy
Independence
“the bottom line”
Ø  Claims that increasing forest carbon/acre contribute to
sustainable carbon reductions fail to account for the
reductions in the one way flow of fossil fuel emissions to
the atmosphere
Ø  Sustainably managed forests are carbon neutral when removals
are set no higher than growth (a balanced 2-way flow)
Ø  Highest carbon efficiency is in our mills
Ø  Lowest carbon efficiency sending residuals to utilities or pellets
although good for long distance transport/sales
Ø  Transport fuels contribute to energy independence as well as
carbon mitigation & should be valued higher
Ø  Domestic jobs and rural income
Ø  Reduced foreign debt
Biofuel LCI/LCA Research Support
from:
USFS-FPL
DOE
several donors,
eight institutions/cooperators
and 20+ authors
For More Information www.corrim.org