Transportation Fuels Life-Cycle Analysis Using the...

Transportation Fuels Life-Cycle Analysis Using the GREET Model

Ignasi Palou‐Rivera Center for Transporta6on Research Energy Systems Division Argonne Na6onal Laboratory ESI Seminar, CAPD, Carnegie Mellon University January 31, 2012

The GREET (Greenhouse gases, Regulated Emissions, and Energy use in Transporta8on) Model   Life‐cycle analysis is an integral part of evalua6on and pursuit

of efficient vehicle technologies and new transporta6on fuels   GREET LCA model development has been supported by US

Department of Energy since 1995   GREET and its documents are available at

hPp://greet.es.anl.gov/   The most recent version of GREET (GREET1_2011) was

released in Oct. 2011   There are more than 14,000 registered GREET users

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The GREET Model Estimates Energy Use and Emissions of GHGs and Criteria Pollutants for Vehicle/Fuel Systems   Energy use

–  Total energy: fossil energy and renewable energy •  Fossil energy: petroleum, natural gas, and coal (they are es6mated separately) •  Renewable energy: biomass, nuclear energy, hydro‐power, wind power, and solar energy

  Greenhouse gases (GHGs) –  CO2, CH4, and N2O –  CO2e of the three (with their global warming poten6als)

  Criteria pollutants –  VOC, CO, NOx, PM10, PM2.5, and SOx –  They are es6mated separately for

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

3

The 2007 EISA and Low-Carbon Fuel Standard Development Require Life-Cycle Analysis for Fuels

  EISA requires LCAs to be conducted to determine if given fuel types meet mandated minimum GHG reduc6ons –  New ethanol produced from corn: 20% –  Cellulosic biofuels: 60% –  Biomass‐based diesel (e.g., biodiesel): 50% –  Other advanced biofuels (e.g., imported sugarcane ethanol, renewable diesel, CNG/LNG

made from biogas): 50% –  EPA released a no6ce of proposed rulemaking (NPRM) in early May

  Low‐carbon fuel standard development efforts in EU, California, and other states require LCAs for biofuels –  Life cycle analysis includes –  All major GHGs (CO2, CH4, and N2O) –  Both produc6on and use of fuels –  Direct and indirect land use change impacts

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ESI Seminar, CAPD, Carnegie Mellon University

4

Key LCA Issues

  System boundary –  Construc6on of infrastructure vs. opera6on stages of the complete life cycle –  Indirect effects primarily via market/pricing effects

  Technology choices for LCAs –  LCA comparison among pathway technologies

•  Fuel produc6on: commercial ones vs. emerging ones s6ll at the R&D stage •  Vehicle technologies: performance equivalency

–  Pathway defini6on: technology op6ons for pathway stages •  Exis6ng vs. emerging •  Environmental sustainability vs. economic viability

–  Inter‐ and intra‐pathway technology choices result in many op6ons; cherry‐picking results from singular dimension can result in erroneous conclusions

  Methods of addressing co‐products of transporta6on fuels   Life‐cycle analysis methodologies

–  APribu6onal LCA: GREET approach –  Consequen6al LCA

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5

Life-Cycle Analysis System Boundary: Petroleum to Gasoline

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Life-Cycle Analysis System Boundary: Corn to Ethanol

Conventional Animal Feed Production

CO2 in the atmosphere

CO2 via photosynthesis

Energy inputs for farming

Fertilizer

N2O emissions from soil and water streams

CO2 emissions during fermentation

CO2 emissions from ethanol combustion Carbon in

ethanol Carbon in kernels

DGS

Direct land use change

Indirect land use changes for other crops and in other

regions

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7

GREET Includes More Than 100 Fuel Produc8on Pathways from Various Energy Feedstocks

The yellow boxes contain the names of the feedstocks and the red boxes contain the names of the fuels that can be produced from each of those feedstocks.

Petroleum Conventional Oil Sands

Compressed Natural Gas Liquefied Natural Gas Liquefied Petroleum Gas Hydrogen Methanol Dimethyl Ether Fischer-Tropsch Diesel Fischer-Tropsch Jet Fuel

Natural Gas North American Shale Gas Non-North American

Coal

Soybeans

Gasoline Diesel Liquefied Petroleum Gas Residual Oil (to electricity) Jet Fuel

Hydrogen Methanol Dimethyl Ether Fischer-Tropsch Diesel Fischer-Tropsch Jet Fuel

Biodiesel Renewable Diesel Renewable Gasoline Renewable Jet Fuel

Sugarcane

Corn

Cellulosic Biomass Switchgrass Fast Growing Trees Crop Residues Forest Residues

Coke Oven Gas Petroleum Coke Nuclear Energy

Residual Oil Coal Natural Gas Biomass Other Renewables

(hydro, wind, solar, geothermal)

Ethanol Butanol

Ethanol

Ethanol Hydrogen Methanol Dimethyl Ether Fischer-Tropsch Diesel Fischer-Tropsch Jet Fuel

Electricity

Hydrogen

Compressed Natural Gas Liquefied Natural Gas Hydrogen Methanol Dimethyl Ether Fischer-Tropsch Diesel Fischer-Tropsch Jet Fuel

Renewable Natural Gas Landfill Gas Biogas from anaerobic digestion

8

Algae

Biodiesel Renewable Diesel Renewable Gasoline Renewable Jet Fuel

1/31/2012 ESI Seminar, CAPD, Carnegie Mellon University

GREET Examines More Than 80 Vehicle/Fuel Systems

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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The Suite of GREET Models

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GREET GUI

GREET SST SST: Stochas;c Simula;on Tool

GUI: Graphic User Interface

GREET 1 Excel model: Fuel‐cycle (or WTW) modeling for light‐duty vehicles

GREET 2 Excel model: Vehicle‐cycle modeling for light‐duty vehicles

GREET CCLUB CCLUB: Carbon Calculator for Land Use Change from Biofuels Produc;on

GREET APD APD: Algae Process Descrip;on


A Process is The Building Block of a Pathway in GREET   A process employs technologies   Technologies employ fuels and may produce emissions

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Energy is defined at process level

Emissions are defined at technology level .

Product

Pathway

Processes

Technologies

Fuels and Material Inputs

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I. Fuels and Material Inputs:

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Product

Pathway

Processes

Technologies


Fer;lizers

Fuels

Electricity

Biomass

Nuclear

Proper6es: Hea6ng Value, C%, S%, etc.

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II. Technologies (Combus;on)

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Emissions

Boilers

Engines

Turbines

Tractors

Trucks

Fuel

Fuel

Fuel

Fuel

Fuel

Important Notes: •  CO2 is calculated by balancing carbon in the

fuel with carbon in emissions

•  SOx may be calculated by balancing sulfur in fuel with sulfur in emissions (if no emissions control)

•  EF for power genera6on technologies may be specified in [g/kWhe]

Emissions Factor (EFi) = Emissions of species i [g]

Unit of Fuel used [mmBtu]

Product

Pathway

Processes

Technologies


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II. Technologies (Light‐Duty Vehicles)

14

Emissions

Fuel

Species vector include:

•  CH4 and N2O

•  VOC, CO, NOx, PM10, and PM2.5

Important Notes: •  CO2 is calculated by balancing carbon in the fuel

with carbon in emissions

•  SOx is calculated by balancing sulfur in fuel with sulfur in emissions

•  Emission factors are independent of fuel economy

•  The vehicle technology is a process by itself (PTW)

Emissions Factor (EFi) = Emissions of species i [g]

Vehicle Miles Travelled [mi]

Product

Pathway

Processes

Technologies


VMT


III. Processes (The Building Blocks of Pathways)

15 Process

Emissions

Process Fuel 1

Process Fuel 2

Process Fuel 3

TECH. 1

TECH. 2

TECH. 3

For Energy: ‐  Define output‐input rela6on (e.g., efficiency) ‐  Define Process Fuel Share

For Emissions: ‐  Define Technology share for each process fuel

Main Product

Product

Pathway

Processes

Technologies


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(a) Energy Accoun;ng: •  Define output‐input rela6on

•  Efficiency (η) = 98% = energy in product/ all energy input

•  TPF = [(1/0.98) – 1] x 1 mmBtu = 20,408 Btu = total process fuel to recover 1 mmBtu of crude

•  Define Process Fuel Share •  2% Residual Oil •  15% Diesel •  62% NG •  21% Electricity

Example of Process Defini;on and Calcula;ons in GREET

16

Crude Recovery (η=98%)

Residual Oil (2%)

Diesel (15%)

Natural Gas (62%) Crude

Electricity (21%)

Total Process Fuel used (TPF) = [(1/η) – 1 ] x product_energy

TPF

Residual oil = 0.02 x 20,408 = 408 Btu Diesel = 0.15 x 20,408 = 3,061 Btu

etc. 1/31/2012 ESI Seminar, CAPD, Carnegie Mellon University

(b) Emissions Accoun;ng: •  Define Technology share for each process fuel

•  Residual Oil 100% Boiler •  Diesel 75% Engine, 25% Turbine •  NG 50% Boiler, 50% Engine •  Electricity Emissions free (at point of use)

Ei = Σj Σk EFi(j, k) . PF(j) . Share (j,k)

Where:

Ei = Total process emissions of pollutant i

EFi(j, k) = Emissions Factor of pollutant i when fuel j is used in technology k

Share (j,k) = Share of fuel j used in technology k

Example of Process Defini;on and Calcula;ons in GREET

17

Crude Recovery

Emissions

Residual Oil (408 Btu)

Diesel (3,061 Btu)

Natural Gas (12,653 Btu)

Boiler

Engine

Crude Turbine

Boiler

Engine

75%

25%

50%

50% Electricity (4,286 Btu)

Example: Eco= [EFCO,RO_Boiler x 1 x 408 + (EFCO,Diesel_Engine x 0.75 + EFCO,Diesel_Turbine x 0.25) 3,061 + (EFCO,NG_Boiler x 0.5 + EFCO,NG_Engine x 0.5) 12,653] 10

‐6 1/31/2012 ESI Seminar, CAPD, Carnegie Mellon University

Example of Process + Upstream

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Upstream

NG Recovery

NG Processing NG

Transporta6on

Oil1%

Gas20%

Coal47%

Nuclear21%

Renewable11%

Process

Crude Recovery

Residual Oil

Diesel

Natural Gas

Electricity

Crude

Emissions

Crude Recovery

Crude Transporta6on

Fuel Transporta6on

Crude Refining


Process Energy I/O Defini;on in GREET

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1.  Efficiency

Example: Electric energy (output) per fuel energy (input)

2.  Yield

Example: Gallons of Ethanol (output) per Bushel of Corn (input)

3.  Energy intensity . Payload . Transporta;on distance

EtOH Dry Mill

Power Plant

Payload [ton]

Distance [mi]

Energy Intensity [Btu/ton‐mi] Payload [ton]

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Three Categories of Process Emissions in GREET

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1.  Combus6on emissions (e.g., engines, boilers, turbines, etc.)

2.  Non‐combus6on emissions (e.g., SMR, GTL, etc.)

3.  Other emissions (from internally produced fuels)

Combus6on Process Fuel 1

Chemical Conversion

Process Fuel 2

internally produced fuel

Main Product

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Process Related Parameters in GREET

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•  Input / output rela6on (e.g., efficiency, yield, energy intensity, etc.)

•  Co‐product amount (e.g., steam, electricity, etc.)

•  Energy for carbon capture and sequestra6on (CCS)

•  Market shares of feedstock or product (Petroleum/oil sands, CG/RFG, electricity genera6on mix, etc.)

•  Technology shares (e.g., NG simple cycle / NG steam cycle / NG combined cycle, Dry mill / wet mill, etc.)

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Product

Pathway

Processes

Technologies


IV. Energy Accoun;ng Throughout A Pathway in GREET

22

Process 1 Process 2 Process 3 Vehicle

Traveling distance

1 1 1 1

Σi xi+upxi Σj yj+upyj

Σk zk+upzk

upfeed

feed fuel

Where:

  upfeed is upstream energy needed to produce 1 unit of feed

  x, y, and z are energy in process fuels or input materials

  upxi is upstream energy needed to produce xi amount of fuel or material i

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Process Co‐Products Handling Methodology in GREET

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•  Several methods are implemented in GREET:

•  Displacement (of equivalent product)

•  Alloca6on

•  Energy‐based

•  Mass‐based

•  Market value‐based

•  Hybrid

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Co‐Product Methods: Benefits and Issues

  Displacement method –  Data intensive: need detailed understanding of the displaced product sector –  Dynamic results: fluctuate with economic and market modifica6ons

  Alloca6on methods: based on mass, energy, or market revenue –  Easy to use –  Frequent updates not required for mature industry, e.g. petroleum refineries –  Mass‐based alloca6on: not applicable for certain cases –  Energy‐based alloca6on: less accurate with non‐fuel co‐products –  Market revenue based alloca6on: subject to price varia6on

  Process energy use approach –  Requires detailed engineering analysis –  Must allocate upstream burdens based on mass, energy, or market revenue

  There is no consensus in policy and research arena on which method is the most appropriate; GREET offers several methods for users to select

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Choice of Co-Product Methods Can Have Significant LCA Effects for Biofuels

25 In Wang et al. (Energy Policy J., 2011)

-120,000

-80,000

-40,000

0

40,000

80,000

C-E

1

C-E

2

C-E

3

C-E

4

C-E

5

G-E

1

G-E

2

G-E

3

S-B

D1

S-B

D2

S-B

D3

S-B

D4

S-R

D1

S-R

D2

S-R

D3

S-R

D4

S-R

D5

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

GH

G E

mis

sion

s (g

/mm

Btu

)

.

PTWWTPWTW

Diesel

D M E $ P D E $ D M E $ $D M E H

Switchgrass to Ethanol Biodiesel Renewable Diesel

Gasoline

Corn Ethanol

D: Displacement M: Mass based E: Energy Based

$: Market Value P: Process Purpose H: Hybrid Alloca6on

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Co-Product Displacement of Equivalent Product

26

Main Product

Emissions

Co‐Product

Process Fuel 1

Process Fuel 2

Process

Displaced Product Feed

Displacement of equivalent amount

Emissions (Credits)

Energy (Credits)

(Credit)

•  Important Notes: •  Main product carry the burden of all process energy and emissions

•  Co‐product does not carry any burden

•  Displaced product is iden6cal or equivalent to co‐product

•  If not iden6cal, a displacement ra6o may apply

•  All life‐cycle energy and emissions of the displaced product are credited to main product

•  For large co‐product/main product ra6o, credits may overwhelm main process emissions

Feed

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Alloca;on of Process Energy and Emissions to Co‐Products

27

Main Product (1‐x)

Emissions

Co‐Product (x)

Process Fuel 1

Process Fuel 2

Process •  Important Notes:

•  x is the ra6o of co‐product in all products by mass, energy, or market value

•  Main product and co‐product carry energy and emissions burden based on their ra6os in the total products

•  The main product and co‐product are equivalent (func6on at end use, quality, etc.)

•  Same process efficiency applies to all products for energy alloca6on (implied)

x 1‐x

x 1‐x x

1‐x

Feed x

1‐x


28

Main Effort and Challenge of LCAs: Data, Data, Data – General Data Sources for GREET

•  Open literature: transparent but much varia6on in data quality •  Process modeling (such as Argonne’s own ASPEN Plus and

Autonomie simula6ons): some6me specula6ve for yet developed commercial technologies

•  Companies and technology developers: osen proprietary and less transparent

•  Engagement of the whole community (LCA prac66oners, researchers, developers, agencies, etc.) and data source transparency are cri6cal

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Two Dis8nctly Different Uncertain8es in LCAs

•  System uncertain6es •  LCA methodology inconsistency: aPribu6onal vs. consequen6al •  System boundary selec6on: a moving target •  Treatment of co‐products •  These issues cause inconsistencies among LCA studies and results

•  Technical uncertain6es related to data availability and quality •  Varia6on in input parameters and output results •  Stochas6c simula6on feature is incorporated in GREET

•  Model and LCA analysis transparency can help advance understanding and consensus building

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30

Sample GREET WTW Results for Selected Vehicle/Fuel Options: Fossil vs. GHGs

From Wang et al. (forthcoming )

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31

Sample GREET WTW Results for Selected Vehicle/Fuel Options: Petroleum vs. GHGs

From Wang et al. (forthcoming ) 1/31/2012


GREET Team at Argonne

  11 staff on LCA research and GREET development –  Dr. Michael Wang: group leader –  Mr. Andy Burnham: vehicle cycle analysis, and natural gas pathways, and GREET user help –  Dr. Corrie Clark: geothermal and shale gas process analysis and water resource/quality assessment –  Dr. Jennifer Dunn: biofuels, soil carbon, baPeries, and GREET applica6ons –  Dr. Amgad Elgowainy: hydrogen fuel vehicles, plug‐in electric vehicles, GREET development –  Dr. Ed Frank: algae‐based biofuels, electric power genera6on systems –  Dr. Jeongwoo Han: renewable natural gas, pyrolysis, vehicle technologies, GREET development –  Ms. Marianne Mintz: renewable natural gas pathways –  Dr. Ignasi Palou‐Rivera: biofuels and petroleum fuels process modeling and LCA applica;ons –  Dr. John Sullivan: vehicle cycle analysis and geothermal and conven6onal power systems –  Dr. May Wu: biofuels and water resource/quality assessment

  Two post‐doctoral researchers on GREET LCA   Four GREET .net programmers   Other organiza6ons who help Argonne

–  MassachusePs Ins6tute of Technology –  Purdue University –  University of Illinois at Chicago and at Urbana‐Champaign –  University of Michigan at Ann Arbor –  The Great Plains Ins6tute

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Extra Slides

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33

GREET Includes Many Biofuel Production Pathways

  Soybeans to –  Biodiesel –  Renewable diesel –  Renewable gasoline –  Renewable jet fuel

34

  Ethanol via fermenta6on from  Corn  Sugarcane  Cellulosic biomass

•  Crop residues •  Dedicated energy crops •  Forest residues

  Renewable natural gas from   Landfill gas   Anaerobic diges6on of

animal wastes

  Cellulosic biomass via gasifica6on to   Fischer‐Tropsch diesel   Fischer‐Tropsch jet fuel

  Corn to butanol

  Cellulosic biomass via pyrolysis to   Gasoline   Diesel

  Algae to   Biodiesel   Renewable diesel   Renewable gasoline   Renewable jet fuel


Electricity Generation Systems in GREET

35

 Coal: Steam Boiler and IGCC   Coal mining and cleaning   Coal transporta6on   Power genera6on

 Natural Gas: Steam Boiler, Gas Turbine, and NGCC   NG recovery and processing   NG transmission   Power genera6on

 Residual Oil: Steam Boiler   Oil recovery and transporta6on   Oil refining   Residual oil transporta6on   Power genera6on

 Nuclear: Light Water Reactor   Uranium mining   Yellowcake conversion   Enrichment   Fuel rod fabrica6on   Power genera6on

 Biomass: Steam Boiler   Biomass farming and

harves6ng   Biomass transporta6on   Power genera6on

 Wind Power

 Hydro Power

 Solar Power via Photovoltaics

 Geothermal Power

Many Hydrogen Produc8on Pathways Are Included in GREET NA NG Central Plant Produc6on:

No C Sequestra6on C Sequestra6on NNA NG

NNA Flared Gas

Nuclear Energy

Biomass

Coal

Methanol Ethanol

Solar Energy

Electricity

Coke Oven Gas

Landfill Gas

Pet Coke

Central Plant Produc6on: HTGR H2O Splivng HTGR Electrolysis

Central Plant Produc6on: No C Sequestra6on C Sequestra6on


Distributed Produc6on

Distributed Produc6on: LWR Electrolysis HTGR Electrolysis

Distributed Produc6on

Central Plant Produc6on via PV

Distributed Produc6on via Electrolysis


Gaseous H2 Liquid H2








Gaseous H2

Central Plant Produc6on

Central Plant Produc6on: Standalone Steam Co‐Genera6on Electric Co‐Genera6on

Central Plant Produc6on: Standalone Electric Co‐Genera6on



HTGR – High‐temp. gas‐cooled reactors LWR – light water reactors

36

Key Steps to Address GHG Emissions of Potential Land Use Changes by Large-Scale Biofuel Production   Simula6ons of poten6al land use changes (in collabora6on with Purdue)

–  Significant efforts have been made in the past three years to improve exis6ng computa6onal general equilibrium (CGE) models

–  More efforts are being made to address addi6onal biomass feedstocks

  Carbon profiles of major land types (in collabora6on with UIC and UIUC) –  Both above‐ground biomass and soil carbon are being considered –  Of the available data sources, some are very detailed (e.g., the DAYCENT model) but

others are very coarse (e.g., the IPCC data) –  There are mismatches between CGE simulated land types and land types in available

carbon databases: satellite data with ground truthing

What Is New in GREET1_2011?

38

•  Algae biofuel pathways, with the algae process descrip6on (APD) with detailed assump6ons of the key stages of the algae pathways

•  Pyrolysis pathways from cellulosic biomass to renewable gasoline and diesel •  Shale gas pathway and updated natural gas pathways •  Renewable natural gas pathways from anaerobic diges6on of animal waste •  Jet fuel pathways, including opera6on of various classes of commercial aircrass •  Op6onal inclusion of energy uses and emissions associated with the construc6on of

petroleum and natural gas wells, coal mines, and various electric power genera6on systems

•  Geothermal power plant op6ons, including both opera6on and construc6on phases •  Updated petroleum recovery and refining efficiencies •  Updated farming assump6ons for corn stover, forest residue, switchgrass,

sugarcane and soybean

Aviation Fuel Options in GREET1_2011

39

 Hydrotreated Renewable Jet Fuel   Soybeans   Palm Oil   Rapeseeds   Jatropha   Camelina   Algae

  Passenger Aircrad   Single Aisle   Small Twin Aisle   Large Twin Aisle   Large Quad   Regional Jet   Business Jet

  Freight Aircrad   Single Aisle   Small Twin Aisle   Large Twin Aisle   Large Quad

 LCA Func;onal Units   Per MJ of fuel   Per kg‐km   Per passenger‐km

Fuels and Feedstocks Aircrad Types  Pyrolysis Oil Jet Fuel

  Crop Residues   Forest Residues   Dedicated Energy Crops

 Fischer‐Tropsch Jet Fuel   North American Natural Gas   Non‐North American Natural Gas   Renewable Natural Gas   Shale Gas   Biomass via Gasifica;on   Coal via Gasifica;on   Coal/Biomass via Gasifica;on

(In collabora6on with MIT PARTNER)

40

Near‐Future GREET Upgrades and Updates

•  An upgraded CCLUB for biofuel LUC GHG emissions •  Expansion on construc6on of fuels produc6on and distribu6on infrastructure •  An upgraded and updated GREET2 vehicle cycle version

•  A detailed baPery LCA module •  Updated energy and emission profiles of key vehicle materials •  A detailed module on vehicle assembling, disposal, and recycling

•  Alpha and beta tes6ng of GREET .net version •  Parallel development of GREET Excel and .net versions

1/31/2012


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