Biofuels and Carbon: Implications for

Powertrain Strategies

John M. DeCiccoUniversity of Michigan Energy Institute

UMTRI Automotive Futures Conference on Powertrain Strategies for the 21st Century

July 22, 2015

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Particular Agricultural

InterestsEnergy Security

Concerns

CO2

Emissions Reduction

Support for Biofuels

Renewable Fuel Standard (RFS)• Legislation 2005 EPAct: RFS1, 7.5 Ggal (billion gallons) by 2012 2007 EISA: RFS2, ramp up to 36 Ggal by 2022, along

with lifecycle GHG targets for categories of fuel

• As in California’s Low-Carbon Fuel Standard (LCFS), an unprecedented requirement to use lifecycle analysis (LCA) for regulation

• Most recent EPA RFS proposed rule 15.9, 16.3, 17.4 Ggal in 2014, 2015, 2016, versus

~18, 20, 22 Ggal, respectively, as called for by EISA Cellulosic biofuel: 33 Mgal, versus 1.75 Ggal in 2014

as called for by EISA

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U.S. biofuel consumption

0

5

10

15

2000 2005 2010 2015

Billi

on G

allo

ns p

er Y

ear

Source: EIA Monthly Energy Review, Tables 3.7, 10.3, 10.4

Ethanol

Biodiesel

For reference, total U.S. liquid motor fuel (gasoline + diesel) consumption was 180 billion gallons per year as of 2014.

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Re-examining the environmental rationale for biofuels

• A growing number of questions are being raised about real-world impacts

• Back to basics: Biofuels and Carbon 101

• What went wrong when developing the prevailing public policy view?

• Policy and strategy implications

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Biofuels are carbon neutral

Source: http://www.ethanolrfa.org/pages/ethanol-facts-environment

The biosphere is already recycling carbon to and from the atmosphere

P = net flow of CO2 from atmosphere into biosphere through photosynthesis (Net Primary Production, NPP)

R = return flow of CO2 from biosphere into atmosphere (Heterotrophic Respiration, Rh) from metabolism by organisms other than primary producers (such as plants, algae, etc.)

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Fuel-related CO2

emissions in the context of the carbon cycle

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Implication: for biofuels to reduce CO2

emissions, feedstock production must meet a necessary condition of:

d(NEP)/dt > 0

i.e., growth and harvest of their feedstock must increase the net rate at which CO2 is removed from the atmosphere.

Schematic for carbon balance analysis of a vehicle-fuel system

End-use CO2emissions

Processemissions

Carbon uptake

System BoundarySoil carbon

Harvest

Carbon imported from fossil resources

MotorFuelProcessing

of feedstocks into products

Carbon exported to feed and food system

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Motor Vehicles

Key carbon flows across system boundary

Fuel ProcessingCropland

Export for Food / Feed

Export in Coproducts

Net CO2Uptake

End-use CO2Emissions

System Boundary

Fossil Resource

Biogenic Process CO2 Emissions

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Carbon balance analysis

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• Examine CO2 flows (both emissions and uptake) when and where they occur Biofuel use per se does not appreciably change

tailpipe CO2 emissions Processing emissions are at least as great for

biofuels as they are for fossil fuels Any potential benefit must come from an increase in

the rate of net CO2 uptake

• Bottom line: No commercial-scale biofuel production meets the

threshold test for a CO2 reduction benefit Production efficiency gains do not change this result

Source: DeCicco, J.M. 2013. Biofuel's carbon balance: doubts, certainties and implications. Climatic Change 121(4): 801-814. dx.doi.org/10.1007/s10584-013-0927-9

Direct GHG emissions impact of using corn ethanol instead of gasoline

+4% +55% +8% +69%

Source: Direct Carbon Balance Accounting for Biofuel Production: Methodology and Case Study, University of Michigan Energy Institute (forthcoming August 2015). 12

What went wrong? • Politically, the strength of one leg of support

(certain agricultural interests) trumped careful analysis of energy and environmental rationales for renewable fuels No one bothered to validate the LCA models used to

justify biofuels’ presumed CO2 benefits The problem is LCA model structure and application

(not just disagreements over data) Argonne's GREET model gives misleading results for

transportation fuels policy

• Congress gave EPA an intractable task California’s LCFS is also deeply flawed

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GREET Model for Fuel Lifecycle Analysis

WHERE IS THE LAND?

Source: Wang, M.Q. 2005. Updated energy and greenhouse gas emissions results for fuel ethanol. 14

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A need to rethink fuel strategies• Lifecycle analysis (LCA) is scientifically incorrect

Not grounded in biogeochemical basics of the carbon cycle Static accounting cannot be used for a dynamic system;

liquid fuels require dynamic stock-and-flow analysis Prior land use (not just land-use change) always matters, but

as practiced to date, LCA misspecifies the baseline

• For transportation fuels, GHG mitigation requires Increasing the rate of net CO2 removal upstream;

substituting fuels downstream has no benefit Replacing fossil carbon with biogenic carbon is not a sufficient

condition for reducing the net CO2 flow to atmosphere

• Implications for vehicle-fuel systems planning Biofuel production likely to stagnate (RFS slowdown/rollback?) Long-term business case for biofuels will erode as policy and

investment strategies face up to scientific and market realities

Toward a better analytic paradigm

Three-Legged Stool Binary Tree

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Clarifying the “Liquid Carbon Challenge”

Reduce the demand for fuel Limit growth of travel demand (control VMT) Reduce vehicle energy intensity (improve MPG)

Reduce GHG impact of the fuel system

Capture carbon onboard vehicles (not feasible)

Use chemically carbon-free fuels (electricity, hydrogen) to shift emissions, and thereby the control problem, somewhere else

Balance CO2 emitted by vehicle with CO2 removal somewhere else• Increase net CO2 uptake in biosphere (raise NEP)

• Avoid CO2 releases that would otherwise occur

• Sequester additional CO2 in the geosphere

Transport sector CO2 mitigation options break down as:

The baseline always

matters!

Source: DeCicco, J.M. 2015. The liquid carbon challenge: evolving views on transportation fuels and climate. WIREs Energy Environ 4(1): 98-114. doi:10.1002/wene.133

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Conclusions• For several decades now, numerous federal and state

policies have sought to catalyze a viable market for alternative transportation fuels Do such efforts rest on sound public policy premises?

• Is replacing petroleum a legitimate policy goal, • or is policy better focused on reducing its associated risks

(which are largely scale related)?

For advanced biofuels in particular, after more than 30 years of R&D and greatly increased public and private investments over the past decade, how credible is the vision?

• Regarding fuels and climate policy: Downstream substitution of liquid fuels provides no climate

mitigation benefit and is therefore a misplaced priority.

As the number of interests that take climate risk seriously grows, support for biofuels will inexorably erode.