1. Jesse Daystar, Richard Venditti, Hasan Jameel, Mike Jett
North Carolina State University
Forest Biomaterials Department
Forest Products Societyβs 65th International Convention on
June 19-21, 2011 in Portland, Oregon.
3. Outline
ο Introduction
ο Research Objective and Goal
ο LCA Approach
ο Goal and Scope
ο Boundaries
ο Data collection
ο Results
ο Conclusions
4. Thermochemical Conversion: Biomass to Biofuels
ο Gasification: conversion of organic or fossil
materials at high temperature without
combustion to produce high energy synthetic
gas
ο The synthetic gas can be
ο burned for energy
ο reacted to produce liquid fuels
ο Advantage: feedstock flexibility (SW, HW, agric
resid, wastes)
8. Research Objectives
ο Life Cycle Analysis (LCA) on forest residuals/thinnings to
ethanol using a thermochemical conversion process (TC
bioethanol)
ο Determine the GHG savings versus gasoline
ο Determine the energy produced per unit of fossil fuel energy
input for the TC bioethanol process
Logging slash: Fs.fed.us
9. LCA Goal:
ο To estimate if a thermochemical conversion process of pine
residuals to ethanol would meet the Renewable Fuel
Standards (60% reduction)
ο Requires GHG data and energy data
ο Basis of Calculation required: Comparison of the production
of 1 MJ of energy from gasoline and from ethanol
11. LCA Boundary: Cradle to Grave
System Boundary
Process Chemicals
Olivine
MgO
Molydbenum
Feedstocks Conversion Process Distribution/Use
Production Fuel transportation
Biomass Gasification
Transportation Combustion emissions
Sequestered Carbon
Landfill Waste Treatment
Inorganic Ash Non-organic effluent
12. Key Assumptions:
ο Forests/plantations sustainably managed
ο Forest residue was a minor co-product and not assigned any
burdens for growing timber
ο Residue decomposition alternate scenario not considered
ο Land use change not studied
ο Equipment manufacture not considered
ο Methane (25X) and N2O (298x) GHG potency wrt CO2 (IPCC,
2006)
13. Methods: Aspen Gasification Model
(Mass and Energy Balances)
ο Developed by NREL: S. Phillips, A. Aden, J. Jechura, and D.
Dayton (2007)
ο Published technical report
ο Thermochemical Ethanol Via Indirect Gasification and
Mixed Alcohol Synthesis of Lignocellulosic Biomass
ο Facility size
ο 772,000 dry tonnes of wood fed/year
ο About 60 gallons per Ton of OD wood
ο About 100 million gallons/year facility
15. Material Balance
Input Stream lb/hr Ouput Stream lb/hr
Clear water chemicals 8.16E-01 Catalyst purge 1.07E+00
Make up catalyst 1.07E+00 Vent to atmosphere 1.90E+00
MgO 6.97E+00 Solid waste 7.94E+01
Char combustor water 2.43E+02 Sulfur storage 1.13E+02
Lo-Cat oxidizer air 2.72E+02 Air to atmosphere 2.80E+02
Make up olivine 5.38E+02 Water to treatment plant 1.21E+03
Steam make up water 3.25E+04 Sand fly ash 2.43E+03
Cooling make up water 8.60E+04 Windage to atmosphere 8.16E+03
Combustion air 2.63E+05 Higher alcohols 9.14E+03
Feedstock 3.34E+05 Blow turbine blow down 1.70E+04
Combustion air 4.30E+05 Ethanol product 5.07E+04
Condensor water 4.08E+06 CO2 vent 5.47E+04
Flue gas stack 9.35E+05
Evaporated to atmosphere 4.23E+06
Total in 5.22E+06 Total out 5.31E+06
% System closure 98.5%
16. Energy Balance
ο Boiler temperature adjusted such that the overall system
purchased energy set to zero
Boiler Temp
Energy +/- GHG Data
Environmental and
Feedstock Data Process Simulation Alcohol Products Adjust Boiler Temp
Economic Analysis
Economic data
Alcohol Products
17. Emissions Data Sources
ο Aspen model
ο Material and energy balance
ο US LCI database emission factors
ο Process chemicals
ο Waste water treatment
ο Waste transportation
ο Inorganic landfill
ο GREET emission factors
ο Fuel combustion
19. GHG Emission Sources
100%
Fuel Combustion
80% 35.90%
Percent of Total GHG Emissions
Fuel Transport
60% Fuel Production
40% Raw Materials
62.23%
Raw Materail Transport
20%
Sequestured Carbon
0%
-20%
-40% -86.95%
-60%
-80%
-100%
MJ Ethanol from Loblolly Pine
20. Global Warming Potential Cradle-to-grave
0.15
1.29E-01
kg CO2 Equivalents per MJ Fuel
0.1 8.66E-02
7.45E-02 7.45E-02
0.05 2.71E-02
4.57E-03 7.24E-03
3.07E-04 1.58E-04
0
3.46E-03 1.58E-04
-0.05
Gasoline
-0.1
Ethanol From Pine
-0.15
-0.2 -1.80E-01
Total Sequestured Raw Materail Raw Materials Fuel Fuel Fuel
Carbon Transport Production Transport Combustion
Axis Title
21. Thermochemical Conversion of Biomass to
Ethanol: 69% reduction in GHG
Lifecycle GHG Thresholds
120%
Specified in EISA
100% (percent reduction from
100%
2005 baseline)
80%
Renewable
20%
60% Gasoline fuela
Advanced
40% 31% Ethanol 50%
biofuel
20% Biomass-
50%
based diesel
0%
Global Warming Potential Cellulosic
60%
biofuel
22. Sensitivity Analysis
ο Evaluated raw material characteristics effects with ASPEN
model simulations:
ο Ξ (kg CO2)/Ξ(% Moisture Content )= 1.0
ο 45% MC is 69% reduction
ο 50% MC is 62% reduction
ο 55% MC is 54% reduction
ο Ξ (kg CO2)/Ξ(% Ash Content )= 0.8
ο MC and Ash (and not chemical composition) correlated with
model results within the set of hybrid poplar, hardwoods, pine,
eucalyptus, corn stover, switchgrass, miscanthus
24. Biomass Gasification for Electricity:
16 units of energy produced/1 unit of fossil fuel input
Life Cycle Assessment of a Biomass Gasification Combined-Cycle System,
Margaret K. Mann, Pamela L. Spath, NREL, 1997
25. Conclusions
ο Biomass growth and emissions during thermochemical
conversion dominate the GHG balance for biothenol
production
ο Production and use of TC bioethanol reduces GHG emissions
by 69% relative to gasoline, qualifies as cellulosic biofuel
ο The production of TC bioethanol produces 4 units of energy
per 1 unit of fossil fuel consumed, lower yield than biomass
gasification to electricity
26. Acknowledgements
ο Consortium for Research on Renewable Industrial Materials
ο Department of Energy
ο Maureen Puettmann β SimaPro assistance
28. CO2 and Temperature
6 320
4 300
2
280
CO2 (ppmv)
0
Temperature
260
-2
240
-4
220
-6
-8 200
-10 180
500000 400000 300000 200000 100000 0
Time (ybp)
Rohling et al. 2009. Antarctic temperature and global sea level closely coupled over the last five glacial cycles. Nature Geoscience 2:500.
29. EISA Renewable Fuel Volume Requirements (billion gallons)
Cellulosic Biomass-based Advanced
Total renewable
Year biofuel diesel biofuel
fuel requirement
requirement requirement requirement
2008 n/a n/a n/a 9.0
2009 n/a 0.5 0.6 11.1
2010 0.1 0.65 0.95 12.95
2011 0.25 0.80 1.35 13.95
2012 0.5 1.0 2.0 15.2
2013 1.0 a 2.75 16.55
2014 1.75 a 3.75 18.15
2015 3.0 a 5.5 20.5
2016 4.25 a 7.25 22.25
2017 5.5 a 9.0 24.0
2018 7.0 a 11.0 26.0
2019 8.5 a 13.0 28.0
2020 10.5 a 15.0 30.0
2021 13.5 a 18.0 33.0
2022 16.0 a 21.0 36.0
2023+ b b b b
30. Predicted GHG Reductions
β’ 138 million metric tons CO2e/year by 2022
β’ Equivalent to removing 27 million vehicles off the road.
β’ 254.4 million registered passenger vehicles in the US,
2007 DOT
30
31. Biofuel GHG Studies
GHG GHG
Feedstock Displacement % S Feedstock Displacement % S
Switchgrass -114 1 Corn -86 9
Switchgrass combustion
compared with coal
combustion -109 2 Corn-soy -38 10
Miscanthus (gasification) -98 3 Corn (starch) -25 11
Switchgrass -93 4 Corn (starch) -24 12
Switchgrass -73 5 Corn -3 13
Switchgrass -11 6 Corn (starch) 66 14
Switchgrass 43 7 Corn (starch) 93 15
Switchgrass 50 8
Sources: 1(Adler, Grosso et al. 2007), 2(Ney and Schnoor 2002), 3(Lettens, Muys et al. 2003), 4(Schmer, Vogel et al. 2008), 5(Wu, Wu et al. 2006),
6(Lemus and Lal 2005), 7(Delucchi 2006), 8(Searchinger, Heimlich et al. 2008), 9(Delucchi, 2006), 10(Adler, Grosso et al. 2007) 11(DiPardo 2004),
12(Wu, Wu et al. 2006), 13(Niven 2005), 14(Delucchi, 2006), 15(Searchinger, Heimlich et al. 2008) (Table modified from Davis et al 2009)
32. Previous GHG Studies
GHG GHG
Feedstock Displacement % S Feedstock Displacement % S
Switchgrass -114 1 Corn -86 9
Switchgrass combustion
compared with coal
combustion Average GHG 2reductions
-109 Corn-soy -38 10
Miscanthus (gasification) -98 3 Corn (starch) -25 11
Switchgrass Cellulosic: 59% (starch)
-93 4 Corn -24 12
Switchgrass -73 5 Corn -3 13
Corn: 2.2%
Switchgrass -11 6 Corn (starch) 66 14
Switchgrass 43 7 Corn (starch) 93 15
Switchgrass 50 8
Sources: 1(Adler, Grosso et al. 2007), 2(Ney and Schnoor 2002), 3(Lettens, Muys et al. 2003), 4(Schmer, Vogel et al. 2008), 5(Wu, Wu et al. 2006),
6(Lemus and Lal 2005), 7(Delucchi 2006), 8(Searchinger, Heimlich et al. 2008), 9(Delucchi, 2006), 10(Adler, Grosso et al. 2007) 11(DiPardo 2004),
12(Wu, Wu et al. 2006), 13(Niven 2005), 14(Delucchi, 2006), 15(Searchinger, Heimlich et al. 2008) (Table modified from Davis et al 2009)
33. LCA Boundary: Cradle to Grave:
ο Residue Collection and Chipping
ο Feedstock Transportation
ο Thermochemical Conversion Process
ο Ethanol Distribution
ο Combustion Logging slash:ysc.nb.ca
34. Upstream and Waste Emissions
30
25
Kg CO2 eq / hour
20
15
10
5
0
MgO Olivine Molydbenum Waste Landfill Landfill
treatment transportation
35. Global Warming Potential: 2005 Study
Life cycle assessment (LCA) of an integrated biomass gasification combined cycle (IBGCC)
with CO2 removal. Matteo Carpentieri *, Andrea Corti, Lidia Lombardi, Energy Conversion
and Management 46 (2005) 1790β1808
36. Global Warming Potential: 1997 Study
Life Cycle Assessment of a Biomass Gasification Combined-Cycle System,
Margaret K. Mann, Pamela L. Spath, NREL, 1997
