Maximum Total Time for Talk 25 minutes

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Maximum Total Time for Talk 25 minutes
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Comparative Sugar Recovery Data from Application
of Leading Pretreatment Technologies to Corn
Stover and Poplar

• Charles E. Wyman, Dartmouth College/University of
  California
• Bruce E. Dale, Michigan State University
• Richard T. Elander, National Renewable Energy
  Laboratory
• Mark T. Holtzapple, Texas AM University
• Michael R. Ladisch, Purdue University
• Y. Y. Lee, Auburn University
• Mohammed Moniruzzaman, Genencor International
• John N. Saddler, University of British Columbia
• 28th Symposium on Biotechnology for Fuels and
  Chemicals
• Nashville, Tennessee
• May 1, 2006

Biomass Refining CAFI
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CAFI Background

• Biomass Refining Consortium for Applied
  Fundamentals and Innovation organized in late
  1999 and early 2000
• Included top researchers in biomass hydrolysis
  from Auburn, Dartmouth, Michigan State, Purdue,
  NREL, Texas AM, U. British Columbia, U.
  Sherbrooke
• Mission
• Develop information and a fundamental
  understanding of biomass hydrolysis that will
  facilitate commercialization,
• Accelerate the development of next generation
  technologies that dramatically reduce the cost of
  sugars from cellulosic biomass
• Train future engineers, scientists, and managers.
  

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CAFI Approach

• Developing data on leading pretreatments using
• Common feedstocks
• Shared enzymes
• Identical analytical methods
• The same material and energy balance methods
• The same costing methods
• Goal is to provide information that helps
  industry select technologies for their
  applications
• Also seek to understand mechanisms that influence
  performance and differentiate pretreatments
• Provide technology base to facilitate commercial
  use
• Identify promising paths to advance pretreatment
  technologies

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USDA IFAFS Project Overview CAFI 1

• Multi-institutional effort funded by USDA
  Initiative for Future Agriculture and Food
  Systems Program for 1.2 million to develop
  comparative information on cellulosic biomass
  pretreatment by leading pretreatment options with
  common source of cellulosic biomass (corn stover)
  and identical analytical methods
• Aqueous ammonia recycle pretreatment - YY Lee,
  Auburn University
• Water only and dilute acid hydrolysis by
  co-current and flowthrough systems - Charles
  Wyman, Dartmouth College
• Ammonia fiber explosion (AFEX) - Bruce Dale,
  Michigan State University
• Controlled pH pretreatment - Mike Ladisch, Purdue
  University
• Lime pretreatment - Mark Holtzapple, Texas AM
  University
• Logistical support and economic analysis - Rick
  Elander/Tim Eggeman, NREL through DOE Biomass
  Program funding
• Completed in 2004

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Hydrolysis Stages
Cellulase enzyme
Stage 2 Enzymatic hydrolysis
Stage 1 Pretreatment
Residual solids cellulose, hemicellulose, ligni
n
Biomass
Solids cellulose, hemicellulose, lignin
Chemicals
Dissolved sugars, oligomers
Dissolved sugars, oligomers, lignin
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Key Features of CAFI Pretreatments
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CAFI 1 Feedstock Corn Stover

• NREL supplied corn stover to all project
  participants (source BioMass AgriProducts,
  Harlan IA)
• Stover washed and dried in small commercial
  operation, knife milled to pass ¼ inch round
  screen

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Consistent Mass Balance Approach as Applied to
AFEX
Enzyme (15 FPU/g of Glucan)
Ammonia
Hydrolyzate
99.0 lb
AFEX
Treated
Stover
Liquid
Hydrolysis
Wash
38.5 lb glucose
System
Stover
100 lb
(Ave. of 4 runs)
101.0 lb
18.9 lb
xylose
Residual
(dry basis)
Solids
Solids washed out
36.1 lb glucan
39.2 lb
2 lb
21.4 lb
xylan
Very few solubles from pretreatmentabout 2 of
inlet stover
95.9 glucan conversion to glucose, 77.6 xylan
conversion to xylose
99 mass balance closure includes (solids
glucose xylose arabinose )
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Calculation of Sugar Yields

• Comparing the amount of each sugar monomer or
  oligomer released to the maximum potential amount
  for that sugar would give yield of each
• However, most cellulosic biomass is richer in
  glucose than xylose
• Consequently, glucose yields have a greater
  impact than for xylose
• Sugar yields in this project were defined by
  dividing the amount of xylose or glucose or the
  sum of the two recovered in each stage by the
  maximum potential amount of both sugars
• The maximum xylose yield is 24.3/64.4 or 37.7
• The maximum glucose yield is 40.1/64.4 or 62.3
• The maximum amount of total xylose and glucose is
  100.

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Overall Sugar Yields from Corn Stover at 60 FPU/g
Glucan
Cumulative soluble sugars as total/monomers.
Single number just monomers.
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Sugar Yields from Corn Stover at 15 FPU/g Glucan
Maximum possible
Dilute acid
Controlled pH
Flowthrough
ARP
Lime
AFEX
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Sugar Yields from Corn Stover at 15 FPU/g Glucan
Maximum possible
Dilute acid
Controlled pH
Flowthrough
ARP
Lime
AFEX
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Sugar Yields from Corn Stover at 15 FPU/g Glucan
Maximum possible
Dilute acid
Controlled pH
Flowthrough
ARP
Lime
AFEX
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Sugar Yields from Corn Stover at 15 FPU/g Glucan
Maximum possible
Dilute acid
Controlled pH
Flowthrough
ARP
Lime
AFEX
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Sugar Yields from Corn Stover at 15 FPU/g Glucan
Maximum possible
Dilute acid
Controlled pH
Flowthrough
ARP
Lime
AFEX
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Sugar Yields from Corn Stover at 15 FPU/g Glucan
Maximum possible
Dilute acid
Controlled pH
Flowthrough
ARP
Lime
AFEX
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Sugar Yields from Corn Stover at 15 FPU/g Glucan
Maximum possible
Dilute acid
Controlled pH
Flowthrough
ARP
Lime
AFEX
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Sugar Yields from Corn Stover at 15 FPU/g Glucan
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CAFI Economic Estimates
Thermodynamics
Process Analogies
Chemistry
Design Methods
CAFI Researcher
Updated Model Basis and Feedstock Basis in CAFI
2 Project
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General Process Flow Diagram
Poplar
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Capital Cost Estimates
Basis 2000 metric tons (dry basis) corn
stover/day, assumes only monomers fermented
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Minimum Ethanol Selling Price (MESP)
Assumptions 2.5 years construction, 0.5 years
start up, 20 year plant life, zero net present
value when cash flows are discounted at 10 real
after tax rate
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Effect of Oligomer Conversion
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Observations for Corn Stover

• All pretreatments were effective in making
  cellulose accessible to enzymes
• Lime, ARP, and flowthrough remove substantial
  amounts of lignin and achieved somewhat higher
  glucose yields from enzymes than dilute acid or
  controlled pH
• However, AFEX achieved slightly higher yields
  from enzymes even though no lignin was removed
• Cellulase was effective in releasing residual
  xylose from all pretreated solids during
  enzymatic hydrolysis in Stage 2
• Xylose release by cellulase was particularly
  important for the high-pH pretreatments by AFEX,
  ARP, and lime, with about half being solubilized
  by enzymes for ARP, two thirds for lime, and
  essentially all for AFEX
• The projected costs were similar due to the high
  yields and similar capital costs for the overall
  processes

Biomass Refining CAFI
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Publication of Results from CAFI 1

• Bruce Dale of the CAFI Team arranged for and
  edited a special December 2005 issue of
  Bioresource Technology entitled Coordinated
  Development of Leading Biomass Pretreatment
  Technologies to document these results
• Wyman CE, Dale BE, Elander RT, Holtzapple M,
  Ladisch MR, Lee YY. 2005. Coordinated
  Development of Leading Biomass Pretreatment
  Technologies, Bioresource Technology 96(18)
  1959-1966, invited.
• Lloyd TA, Wyman CE. 2005. Total Sugar Yields for
  Pretreatment by Hemicellulose Hydrolysis Coupled
  with Enzymatic Hydrolysis of the Remaining
  Solids, Bioresource Technology 96(18)
  1967-1977, invited.
• Liu C, Wyman CE. 2005. "Partial Flow of
  Compressed-Hot Water Through Corn Stover to
  Enhance Hemicellulose Sugar Recovery and
  Enzymatic Digestibility of Cellulose,
  Bioresource Technology 96(18) 1978-1985,
  invited.
• Mosier N, Hendrickson R, Ho N, Sedlak M, Ladisch
  MR. 2005. Optimization of pH Controlled Liquid
  Hot Water Pretreatment of Corn Stover, Bioresourc
  e Technology 96(18) 1986-1993, invited.
• Kim S, Holtzapple MT. 2005. Lime Pretreatment
  and Enzymatic Hydrolysis of Corn
  Stover, Bioresource Technology 96(18)
  1994-2006, invited.
• Kim TH, Lee YY. 2005. Pretreatment and
  Fractionation of Corn Stover by Ammonia Recycle
  Percolation Process, Bioresource Technology
  96(18) 2007-2013, invited.
•  Teymouri F, Laureano-Perez L, Alizadeh H, Dale
  BE. 2005. Optimization of the Ammonia Fiber
  Explosion (AFEX) Treatment Parameters for
  Enzymatic Hydrolysis of Corn Stover, Bioresource
  Technology 96(18) 2014-2018, invited.
• Eggeman T, Elander RT. 2005. Process and
  Economic Analysis of Pretreatment Technologies,
  Bioresource Technology 96(18) 2019-2025,
  invited.
• Wyman CE, Dale BE, Elander RT, Holtzapple M,
  Ladisch MR, Lee YY. 2005. Comparative Sugar
  Recovery Data from Laboratory Scale Application
  of Leading Pretreatment Technologies to Corn
  Stover, Bioresource Technology 96(18)
  2026-2032, invited.

Biomass Refining CAFI
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DOE OBP Project April 2004 Start

• Funded by DOE Office of the Biomass Program for
  1.88 million through a joint competitive
  solicitation with USDA
• Using identical analytical methods and feedstock
  sources to develop comparative data for corn
  stover and poplar
• Determining more depth information on
• Enzymatic hydrolysis of cellulose and
  hemicellulose in solids
• Conditioning and fermentation of pretreatment
  hydrolyzate liquids
• Predictive models
• Added University of British Columbia to team
  through funding from Natural Resources Canada to
• Capitalize on their expertise with xylanases for
  better hemicellulose utilization
• Evaluate sulfur dioxide pretreatment along with
  those previously examined dilute acid,
  controlled pH, AFEX, ARP, lime
• Augmented by Genencor to supply commercial and
  advanced enzymes

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Tasks for the DOE OBP Project

• Pretreat corn stover and poplar by leading
  technologies to improve cellulose accessibility
  to enzymes
• Enzymatically hydrolyze cellulose and
  hemicellulose in pretreated biomass, as
  appropriate, and develop models to understand the
  relationship between pretreated biomass features,
  advanced enzyme characteristics, and enzymatic
  digestion results
• Develop conditioning methods as needed to
  maximize fermentation yields by a recombinant
  yeast, determine the cause of inhibition, and
  model fermentations
• Estimate capital and operating costs for each
  integrated pretreatment, hydrolysis, and
  fermentation system and use to guide research

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CAFI 2 Corn Stover

• 2nd pass harvested corn stover from Kramer farm
  (Wray, CO)
• Collected using high rake setting to avoid soil
  pick-up
• No washing
• Milled to pass ¼ inch round screen

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CAFI 2 Standard Poplar

• Feedstock USDA-supplied hybrid poplar
  (Alexandria, MN)
• Debarked, chipped, and milled to pass ¼ inch
  round screen

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Hydrolysis Stages
Cellulase enzyme
Stage 2 Enzymatic hydrolysis
Stage 1 Pretreatment
Residual solids cellulose, hemicellulose, ligni
n
Biomass
Solids cellulose, hemicellulose, lignin
Chemicals
Dissolved sugars, oligomers
Dissolved sugars, oligomers, lignin
Stage 3 Sugar fermentation
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CAFI 2 Pretreated Substrate Schedule
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Overall Yields for Corn Stover at 15 FPU/g Glucan
Cumulative soluble sugars as total/monomers.
Single number just monomers.
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Effect of Pretreatment Severity on Enzymatic
Hydrolysis of Dilute Acid Pretreated Poplar
CBUFPU 2.0 Digestion time 72hr
2 glucan concentration 50 FPU/ gm original glucan
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Effect of Protein Loadings on Cellulose
Hydrolysis of Poplar Solids
Digestion time 72hr
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Effect of Protein Loadings on Cellulose
Hydrolysis of Poplar Solids
Digestion time 72hr
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Effect of Protein Loadings on Cellulose
Hydrolysis of Poplar Solids
Digestion time 72hr
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CAFI 2 Initial Poplar

• Feedstock USDA-supplied hybrid poplar
  (Arlington, WI)
• Debarked, chipped, and milled to pass ¼ inch
  round screen
• Not enough to meet needs

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CAFI 2 Initial Poplar

• Feedstock USDA-supplied hybrid poplar
  (Arlington, WI)
• Debarked, chipped, and milled to pass ¼ inch
  round screen
• Not enough to meet needs

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C - Cellulase (31.3 mg/g glucan) X -
Xylanase (3.1 mg/g glucan) A - Additive (0.35g/g
glucan)
UT - Untreated AFEX condition 24 h water
soaked 11 (PoplarNH3) 10 min. res. time
AFEX Optimization for High/Low Lignin Poplar
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Differences Among Poplar Species
Based on information provided by Adam Wiese,
USDA Rheinlander, WI
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Fermentation of Dilute Acid Treated Corn Stover
Ca(OH)2
S. cerevisiae 424A(LNH-ST)
H2SO4
B
corn stover
Fermentation 30?C
Ethanol
175?C
Liquid
A
pH 6.0
pH 1.2
Solids
Cells
pH 1.2
A
B
Stream
g/L
g/L
80 of theoretical
Inhibitor
consumed
consumed
43
Fermentation of Hot Water Treated Corn Stover
Ca(OH)2
S. cerevisiae 424A(LNH-ST)
Water
Enzyme
B
corn stover
Fermentation 30?C
Ethanol
190?C
50?C
A
pH 6.0
pH 4.5
Cells Solids
A
B
Stream
g/L
g/L
95 of theoretical
No Xylanase
below threshold
consumed
consumed
44
Fermentation of SO2 Treated Corn Stover
SO2
Enzyme
S. cerevisiae 424A(LNH-ST)
Ca(OH)2
Ca(OH)2
B
corn stover
Fermentation 30?C
180?C
50?C
Ethanol
A
pH 1
pH 4.8
pH 6.0
Cells
Solids
A
B
Stream
g/L
g/L
96 of theoretical
No Xylanase
below threshold
consumed
consumed
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Observations

• The yields can be further increased for some
  pretreatments with enzymes a potential key
• Mixed sugar streams will be better used in some
  processes than others
• Oligomers may require special considerations,
  depending on process configuration and choice of
  fermentative organism
• Initial data on conditioning and fermentation
  shows mostly good yields
• All pretreatments gave similar results for corn
  stover
• Initial hydrolysis results for poplar are not as
  good, with one variety more recalcitrant than
  other

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Planned Work

• Maximize yields with standard poplar for each
  pretreatment
• Evaluate differences with initial poplar at
  optimal conditions for standard poplar
• Develop fermentation data with hydrolyzate for
  each material
• Upgrade technoeconomic model with corn stover and
  poplar
• Identify key features that distinguish
  performance of different pretreatments

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Acknowledgments

• US Department of Agriculture Initiative for
  Future Agricultural and Food Systems Program,
  Contract 00-52104-9663
• US Department of Energy Office of the Biomass
  Program, Contract DE-FG36-04GO14017
• Natural Resources Canada
• All of the CAFI Team members, students, and
  others who have been so cooperative

Biomass Refining CAFI
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CAFI DOE Project AI Advisory BoardMeetings
Every 6 Months

• Quang Nguyen, Abengoa Bioenergy
• Mat Peabody, Applied CarboChemicals
• Gary Welch, Aventinerei
• Greg Luli, BC International
• Paris Tsobanakis, Cargill
• Robert Wooley, Cargill Dow
• James Hettenhaus, CEA
• Steve Thomas, CERES
• Lyman Young, ChevronTexaco
• Kevin Gray, Diversa
• Paul Roessler, Dow
• Julie Friend, DuPont
• Jack Huttner, Genencor

• Don Johnson, GPC (Retired)
• Dale Monceaux, Katzen Engineers
• Kendall Pye, Lignol
• Farzaneh Teymouri, MBI
• Richard Glass, National Corn Growers Association
• Bill Cruickshank, Natural Resources Canada
• Robert Goldberg, NIST
• Joel Cherry, Novozymes
• Ron Reinsfelder, Shell
• Andrew Richard, Sunopta
• Carl Miller, Syngenta
• Carmela Bailey, USDA
• Don Riemenschneider, USDA

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Questions??
Louisiana Rice Hulls Pile