GREET BIOFUEL LIFE-CYCLE ANALYSIS AND RESULTS

MICHAEL WANG 王全录Systems Assessment GroupEnergy Systems DivisionArgonne National Laboratory

The IEA Bioenergy Forum: Commercialising Conventional and Advanced Liquid Biofuels from Biomass Beijing, China, April 7-8, 2018

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Transportation life-cycle analysis models

The GREET model in the U.S since 1994 The EU WTW study since 2003 The Canadian GHGenius since 2001 MIT LCA of jet fuels since 2008

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The GREET® (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) model

GREET 1 model: Fuel-cycle (or well-to-wheels, WTW) modeling of

vehicle/fuel systems

Stochastic Simulation Tool

Carbon Calculator for Land Use Change from Biofuels (CCLUB)

GR

EET 2 model:

Vehicle cycle modeling for vehicles

• Available at www.greet.es.anl.gov• Update and release annually• Supported by three DOE EERE transportation

R&D offices

Energy use – transportation energy diversification Total energy: fossil energy and renewable energy

• Fossil energy: petroleum, natural gas, and coal (they are estimated separately)• Renewable energy: biomass, nuclear energy, hydro-power, wind power, and solar

energy

Greenhouse gases (GHGs) – climate changes CO2, CH4, N2O, black carbon, and albedo CO2e of the five (with their global warming potentials)

Air pollutants – urban air pollution VOC, CO, NOx, PM10, PM2.5, and SOx They are estimated separately for

• Total (emissions everywhere)• Urban (a subset of the total)

Water consumption – water sustainability GREET LCA functional units Per service unit (e.g., mile driven, ton-mi) Per unit of output (e.g., million Btu, MJ, gasoline gallon equivalent) Per units of resource (e.g., per ton of biomass)

GREET outputs include energy use, greenhouse gases, criteria pollutants and water consumption for vehicle and energy systems

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GREET includes all transportation subsectors

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• Desire to control air pollution in ports globally• Interest by EPA, local governments, IMO• GREET includes Ocean and inland water transportation Baseline diesel and alternative marine fuels

• Globally, a fast growing sector with GHG reduction pressure

• Interest by DOD, ICAO, FAA, and commercial airlines

• GREET includes Passenger and freight transportation Various alternative fuels blended with

petroleum jet fuels

• Light-duty vehicles• Medium-duty vehicles• Heavy-duty vehicles• Various powertrains:

Internal Combustion EnginesElectrics Fuel cells

• Interest by FRA, railroad companies

• Potential for CNG/LNG to displace diesel

1 - Overview

Roadtransportation

Airtransportation

Railtransportation

Marinetransportation

GREET includes more than 100 fuel production pathways from various energy feedstock sources

PetroleumConventional crudeShale oilOil Sands

Compressed Natural GasLiquefied Natural GasLiquefied Petroleum GasMethanolDimethyl EtherFischer-Tropsch DieselFischer-Tropsch Jet FuelFischer-Tropsch NaphthaHydrogen

Natural GasNorth AmericanNon-North AmericanShale gas

CoalSurface miningUnderground mining

SoybeansPalmRapeseedJatrophaCamelinaAlgae

GasolineDieselJet FuelLiquefied Petroleum GasNaphthaResidual Oil

HydrogenFischer-Tropsch DieselFischer-Tropsch Jet FuelMethanolDimethyl Ether

BiodieselRenewable DieselRenewable GasolineRenewable Jet Fuel

Sugarcane

Corn

Cellulosic BiomassSwitchgrassWillow/PoplarCrop ResiduesForest ResiduesMiscanthus

Residual OilCoalNatural GasNuclearBiomassOther Renewables

EthanolButanolJet fuel

EthanolJet Fuel

EthanolHydrogenMethanolDimethyl EtherFischer-Tropsch DieselFischer-Tropsch Jet FuelPyro Gasoline/Diesel/Jet

Electricity

Renewable Natural GasLandfill GasAnimal WasteWaste water treatment

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Coke Oven GasPetroleum CokeNuclear EnergyElectricity from different sources

Hydrogen

GREET includes various biomass feedstocks, conversion technologies, and fuels

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Grains, sugars, and cellulosics Ethanol, butanol

Cellulosics Drop-in hydrocarbon fuels

Aviation and marine fuels

Fermentation, Indirect Gasification

Algae and oil crops

Gasification (e.g., FT), Alcohol to Jet, Sugar to Jet

Hydroprocessing

Biodiesel

Renewable diesel

Transesterification

Hydroprocessing, Hydrothermal Liquefaction

Pyrolysis, Fermentation, Gasification (e.g., FT)

1 - Overview

Waste feedstock Natural gas and derivativesAnaerobic Digestion

ElectricityCombustion

Combustion

Renewable dieselHydrothermal LiquefactionFermentation

GHG reduction requirements of EPA’s Renewable Fuel Standard (RFS) are on LCA basis

Renewable fuel (D6) – 20% GHG reduction- Plants existing before 2008- Corn ethanol- Corn starch butanol- Sorghum ethanol w/NG process energy

Compliance of fuel with RFS determined by EPA based on lifecycle greenhouse gas emissions

Use of suite of models, including GREET for LCA Land use change (LUC) emissions included for biofuels

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Advanced biofuels (D5) – 50% GHG reduction

- Sugarcane ethanol- Naphtha and LPG from camelina- Sorghum ethanol w/ bioenergy

Biomass-based diesel (D4) – 50% GHG reduction

- Biodiesel (BD) and renewable diesel (RD) from soy, corn, rapeseed, camelina, algal and waste oils, fats and greases

- BD produced using esterification- RD w/ electricity and NG process energy- BD produced using glycerolysis and

transesterification

Cellulosic biofuels (D3) – 60% GHG reduction- Cellulosic diesel or ethanol from switchgrass,

miscanthus, energy cane, giant reed and napiergrass

- Fuels from crop residue, forest material, secondary cover crops on existing crop land, cellulose from food and yard waste

- Thermochemical pyrolysis, thermochemical gasification, biochemical direct fermentation, biochemical fermentation w/ catalytic upgrading w/ biomass process energy

California Low-Carbon Fuel Standard (LCFS) promotes low-carbon, liquid fuels

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Adopted in 2009 by the State of California To reduce California’s transportation fuel carbon intensity (CI) by

10% in 2020 relative to 2010 Gasoline Diesel Alternative fuels Electricity and hydrogen

GHG emissions for various fuels are determined on LCA basis Carbon intensity (CI), in grams of GHGs (CO2, CH4, and N2O), is the measure

of GHG emissions associated with producing and consuming a fuel GREET was adapted to CA-GREET to decide fuel’s LCA GHG intensity (or well-

to-wheels CI) LCFS has been the most successful program so far; CARB is now

deciding LCFS requirement for after 2020

Key factors determining biofuel LCA results

LCA system boundary

Feedstock types

Conversion technologies: energy balance and materials inputs such as enzyme and catalyst

Technology improvement over time

Biorefineries with distinctly different products: co-product methods

Direct and indirect land use changes

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GREET system boundary for biofuel LCA: direct activities and indirect effects are included

WTW analysis of petroleum fuel pathways

Refining process Second-largest GHG emissions source in fuel cycle Complex system with multiple co-products Key process for assessing the impact of producing

HOF12

Petroleum Refining

Key factors determining biofuel LCA results

LCA system boundary

Feedstock types

Conversion technologies: energy balance and materials inputs such as enzyme and catalyst

Technology improvement over time

Biorefineries with distinctly different products: co-product methods

Direct and indirect land use changes

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GREET renewable jet fuel GHGs: feedstock and conversion are key drivers

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Based on GREET2016. Emissions from land use change is not included.

GREET life-cycle GHG emissions of selected biofuels: feedstock is the main driver

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9557

328 11 -4

-150

-100

-50

0

50

100

150

With LUC Without LUC With LUC With LUC With LUC

Gasoline Corn ethanol Sugarcaneethanol

Corn stoverethanol

Switchgrassethanol

Miscanthusethanol

WTW

GH

G e

mis

sion

s, g

CO

2e/M

JWTP Biogenic CO₂ in Fuel PTW LUC WTW

3 - Accomplishments

Emission breakout for two ethanol types

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Corn Ethanol

Corn Stover Ethanol

Key factors determining biofuel LCA results

LCA system boundary

Feedstock types

Conversion technologies: energy balance and materials inputs such as enzyme and catalyst

Technology improvement over time

Biorefineries with distinctly different products: co-product methods

Direct and indirect land use changes

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Fertilizer use in U.S. corn farming has reduced significantly in the past 40 years

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This is US annual statistics. Measured data at farm level will help biofuel LCA move to finer resolution.

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010

Dry Mill Wet Mill Average

Historical Ethanol Plant Energy Use: Btu/Gallon

Historical trend of energy use in U.S. corn ethanol plants

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Key factors determining biofuel LCA results

LCA system boundary

Feedstock types

Conversion technologies: energy balance and materials inputs such as enzyme and catalyst

Technology improvement over time

Biorefineries with distinctly different products: co-product methods

Direct and indirect land use changes

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Integrated production of grain and stover ethanol can help further GHG reductionsEthanol with corn grain and corn stover can energy and

cost synergy for ethanol production

•21 Canter et al., BioEneg. Res., 2015.

Process

Material and Energy Flows

Heat

Electricity

Choice of co-product methods can have significant LCA effects

-120,000

-80,000

-40,000

0

40,000

80,000

C-E1

C-E2

C-E3

C-E4

C-E5

G-E

1

G-E

2

G-E

3

S-BD

1

S-BD

2

S-BD

3

S-BD

4

S-RD

1

S-RD

2

S-RD

3

S-RD

4

S-RD

5

. Gasoline . Diesel . Corn-EtOH . Switchgrass - EtOH . Biodiesel . Renewable Diesel .

GHG

Em

issi

ons

(g/m

mBt

u)

.

PTWWTPWTW

Soybean

Soy Meal

Soy Oil Naphtha

Jet Fuel

Light Ends

Renewable Diesel

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Choice of benefits from CHP-produced heat influences life-cycle GHG emissions of co-produced fuels

Corn ethanol GHG emissions are below emissions for corn ethanol produced in a stand-alone facility Stover ethanol life-cycle GHG

emissions are higher than when it is treated as a stand-alone fuel Treat Allocation strongly affects

results and should be transparently documented

•23Canter et al., BioEneg. Res., 2015.

Net GHG emissions for corn grain and stover ethanol for the baseline and the two alternative CHP usage scenarios. The 20%, 50%, and 60% GHG reduction lines represent the targets for the corresponding reduction in GHG emissions compared with gasoline at 94 g CO2eq/MJ. The line for grain ethanol and stover ethanol represent the GHG emissions to produce these fuels in a non-integrated scenario.

Paper to be published in BioFPR

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Co-product handling methods and results for integrated biorefineries (IBR) with fuels and products

IBRs with significant amount of biochemicals pose challenges to fuel LCA

– Fuel-specific LCA GHGs can be greatly impacted by the co-produced biochemicals• IBRs are highly integrated for heat needs and products; difficult and

unrealistic to separate inputs into different products from IBRs• Various co-product methods are adopted in LCA of a specific product

– Current fuel-focused GHG regulations, i.e., RFS and LCFS, do not directly consider GHG benefits of biochemicals• Fuel-specific LCA results are highly dependent on co-product

handling methods• Fuel-specific LCA results may or may not include the biochemical

GHG impacts, depending on co-product handling methods, and thus may cause potential “positive” leakage of GHG reduction benefits from biochemicals

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Evaluated IBR produces renewable diesel blendstock (RDB) and succinic acid (SA)– A significant amount of co-produced SA: 62.6 kg SA per mmBtu of RDB

LCA of IBR: the succinic acid (SA) case

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Co-product methods for fuels: displacement, IBR system-level allocation, and process-level allocation

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Pathways Co-product handling methods Allocation basis

a) RDB production only No co-product method needed

b) RDB in RDB/SA co-production

System-level allocation

Carbon efficiencyMarket value, 100% of current SA priceMarket value, 50% of current SA priceMass

Process-level allocation

Carbon efficiencyMarket value, 100% of current SA priceMarket value, 50% of current SA priceMass

DisplacementSA displacing petroleum-derived maleic anhydride

c) RDB in RDB/AA co-production

System-level allocation

Carbon efficiencyMarket value, 100% of current AA priceMarket value, 50% of current AA priceMass

Process-level allocation

Carbon efficiencyMarket value, 100% of current AA priceMarket value, 50% of current AA priceMass

Displacement AA displacing natural gas-derived AA

Life-cycle GHG emissions of RDB from IBRs with co-production of SA

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Biorefinery-level integrated LCA Link product-specific emission results to IBR production volumes for specific

products Provide facility-level LCA with total emission changes and contributions of

individual products Present results of the entire facility

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-2,000,000

-1,500,000

-1,000,000

-500,000

0

500,000

1,000,000

RDB Only with No Co-product Design SA Co-production Design AA Co-production Design

CO

2e, m

etric

tons

/yea

r

Annual biorefinery-level GHG emission reductions

Biorefinery total GHG emissions RDB displacement emission creditBio-chemical displacement emission credit Biorefinery total GHG emission reduction

Corn ethanol plant: grain ethanol, corn oil biodiesel, corn fiber ethanol (manuscript submitted to BioFPR)

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(a) The pathway is based on corn starch ethanol production with corn oil extraction (dry mill) . Main products include starch and fiber ethanol. The co-products DGS and corn oil are displaced by animal feed and soy oil, respectively. (b) Co-products are treated with combined ethanol approach. (c) Co-products are treated with separate ethanol approach.

Corn grain ethanol vs. corn fiber ethanol GHG results

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-20.0

0.0

20.0

40.0

60.0

80.0

Starch ethanol,conventional

Starch and fiberethanol, nth

Starch ethanol,nth

Fiber ethanol,nth

GH

G e

mis

sion

s (g

CO

2e M

J-1 )

Corn Ethanol Vehicle DGS Oil Total

b Gasoline (94)

20% reduction

50% reduction60% reduction

100% reduction

-20.0

0.0

20.0

40.0

60.0

80.0

Starch ethanol,conventional

Starch and fiberethanol, SOT

Starch ethanol,SOT

Fiber ethanol,SOT

GH

G e

mis

sion

s (g

CO

2e M

J-1 )

Corn Ethanol Vehicle DGS Oil Total

a Gasoline (94)

20% reduction

50% reduction60% reduction

100% reduction

(a) SOT and (b) nth plant technology

Trend of estimated LUC GHG emissions for corn and sugarcane ethanol

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Critical factors for LUC GHG emissions: Land intensification vs. extensification

• Crop yields: existing cropland vs. new cropland; global yield differences and potentials• Double cropping on existing land• Extension to new land types: cropland, grassland, forestland, wetland, etc.

Price elasticities• Crop yield response to price• Food demand response to price

Soil organic carbon changes from land conversions and land management

Corn Ethanol 0

5

10

15

20

25

30

35

40

45

50

CAR

B20

09

EPA

2010

Labo

rde

2011

CAR

B20

15

EU F

QD

(pro

p.)

2015

ECO

FSY

2015

LUC

GH

G E

mis

sion

s (g

CO

2e/M

J)

Sugarcane Ethanol

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Carbon Calculator for Land Use Change from Biofuels (CCLUB) module in GREET

GREET LCA water consumption results (L/GJ): irrigation for biofuel feedstocks can increase water use

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• Water LCA accounts for life-cycle freshwater consumption of transportation fuel production by evaluating the entire supply chain for each production pathway.

• Major water consumers include irrigation for biofuel feedstocks, and hydro- and thermo-electric power plants.

Biomass additionality argument questions whether bioenergy systems have carbon reductionsOnly additional biomass growth in biophysical systems can

result in carbon neutrality for bioenergyBiomass additionality by bioenergy

– Switch between biomass uses among different purposes vs. additional biomass growth: • Productivity of different biophysical systems • Biomass growth: managed systems vs. natural

biophysical systems – Length of carbon cycle of biomass feedstocks is a key

dimension• Annual: annual crops and perennial grasses• A few years: short-rotation trees• 50-100 years: forests

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ConclusionsGREET has become a standard LCA tool to examine energy and

environmental footprints of energy systemsGREET has been used by EPA and CARB to develop RFS and LCFS

regulations; it is now a compliance tool for LCFSGREET biofuel LCA includes all activities for biomass growth: Farming energy input Fertilizer production and use Farming management practices

High-level biofuel result summary Biofuel LCA results are dominated by feedstock types (1st gen., 2nd gen., and

3rd gen. feedstocks) Conversion technologies to produce hydro-carbon fuels and jet fuels require

hydrogen Farming management practices can affect biofuel sustainability in general

and LCA GHG results in particular

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Please visithttp://greet.es.anl.gov for:

• GREET models• GREET documents • LCA publications

• GREET-based tools and calculators

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There are nearly 30,000 registered GREET users globally

Geographically, 71% in North America, 14% in Europe, 9% in Asia

57% in academia and research, 33 % in industries, 8% in governments

GREET examines more than 80 on-road vehicle/fuel systems for both LDVs and HDVs

Conventional Spark-Ignition Engine Vehicles Gasoline Compressed natural gas, liquefied natural gas,

and liquefied petroleum gas Gaseous and liquid hydrogen Methanol and ethanol

Spark-Ignition, Direct-Injection Engine Vehicles Gasoline Methanol and ethanol

Compression-Ignition, Direct-Injection Engine Vehicles Diesel Fischer-Tropsch diesel Dimethyl ether Biodiesel

Fuel Cell Vehicles On-board hydrogen storage

– Gaseous and liquid hydrogen from various sources

On-board hydrocarbon reforming to hydrogen

Battery-Powered Electric Vehicles Various electricity generation sources

Hybrid Electric Vehicles (HEVs) Spark-ignition engines:

– Gasoline– Compressed natural gas, liquefied natural

gas, and liquefied petroleum gas– Gaseous and liquid hydrogen– Methanol and ethanol

Compression-ignition engines– Diesel– Fischer-Tropsch diesel– Dimethyl ether– Biodiesel

Plug-in Hybrid Electric Vehicles (PHEVs) Spark-ignition engines:

– Gasoline– Compressed natural gas, liquefied natural

gas, and liquefied petroleum gas– Gaseous and liquid hydrogen– Methanol and ethanol

Compression-ignition engines– Diesel– Fischer-Tropsch diesel– Dimethyl ether– Biodiesel

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GREET approach and data sources Approach Build a consistent LCA platform with reliable, widely accepted methods/protocols Address emerging LCA issuesMaintain openness and transparency of LCAs by making GREET publicly

available Primarily process-based LCA approach (the so-called attributional LCA); some

features of consequential LCA are incorporated

Data sources Open literature and results from other researchers DOE and other agencies R&D results

Fuel producers and technology developers for fuels and automakers for vehicles

Simulations with models such as ASPEN Plus for fuel production and ANL Autonomie and EPA MOVES for vehicle operations

Baseline technologies and energy systems: EIA Annual Energy Outlook (AEO) projections, EPA eGrid for electric systems, etc.

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US Federal Renewable Fuel Standard (RFS) promotes biofuels in transportation

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US biofuel volumes under the RFS program

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0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

2010 2011 2012 2013 2014 2015 2016 2017

M g

al/Y

r

Cell. biofuel (D3) Adv. Biofuel (D5) Biomass-based diesel (D4) Rew. Fuel (D6)

From Bob Lane of Jacobsen

California LCFS has increased alternative fuels significantly

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0200400600800

1,0001,2001,4001,6001,8002,000

2011 2012 2013 2014 2015 2016

Mill

on G

allo

n Eq

uiva

lent

s (G

GE)

Ethanol Biodiesel Renewable Diesel Fossil Natural Gas Biomethane Electricity

Ethanol LCFS credits LCFS: $90-100/ton CO2 (imputed from LCFS trading) CA economy-wide carbon market: $13-15/ton CO2 With $100/ton LCFS CO2 price; a gallon of ethanol has LCFS credit:

EtOH CI: gCO2e/MJ LCFS value: $/gal EtOH

70 (corn EtOH) $0.45

50 (corn EtOH) $0.81

30 (sugarcane EtOH) $1.1710 (Cell EtOH) $1.53

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LUC-related GHG emissions vary significantly among biofuel feedstocks

LUC GHG emissions

(g CO2eq MJ-1)WTW GHG

w/o LUC

(g CO2e MJ-1)

WTW GHG w/

LUC

(g CO2e MJ-1)Domestic International Total

Corn 1.4 ‒ 4.3 5.0 6.4 ‒ 9.3 57.1 63.5 ‒ 66.4

Miscanthus -22.3 ‒ -16.3 2.2 -20.1 ‒ -14.1 13.5 -6.7 ‒ -0.6

Note: 1) LUC GHG emissions are based on 100cm soil depth; variations reflect types of land impacted and land management practices.2) Conversion of cropland to cornfield with sustainable stover removal could result in increased SOC; conversion of grassland or forest to cornfield could result in decreased SOC

For cellulosic feedstocks, conversion of cropland and grassland to energy grass fields (e.g., Miscanthus farms) could increase or maintain SOC

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Production of bioenergy feedstocks can cause land-use change and/or land management change

Forest, grassland, cropland, cropland-pasture CroplandLand types

Land Use Change Land Management Change

Land Management

Feedstock Options

Conventional, reduced and no Till Cover crop, manure application

Corn grain

Corn stoverPoplarMiscanthusSwitchgrassSoy Willow

SOC changes upon land transition vary spatially and by feedstock type

From Cropland Pasture From Forest

To C

orn

To M

isca

nthu

s

SOC rate t ha-1 yr-1

Qin et al., GCB Bioenergy, 2016.