2005 OBP Biennial Peer Review

1. 2005 OBP Biennial Peer Review Pretreatment & Enzymatic Hydrolysis Rick Elander (NREL) Biochemical Conversion Platform November 15, 2005

2. Work Breakdown Structure NREL Academia Industry Earmark

3. Platform Fit with Pathways Integrated Biorefineries Feedstock R&D Sugars R&D Thermochemical R&D Products R&D (from) Program Outputs Corn Wet Mill Improvements (Corn) • Residual Starch Conversion • Fiber Conversion Systems-level demonstration and validation by 2009 • Aventine/Purdue • Residual Starch Conversion • Fiber Conversion • Milled Grain Fractionation Corn Dry Mill Improvements (Corn, Grain) Systems-level demonstration and validation by 2012 • CAFI 2 • Feedstock Qualification • Enzymatic Hydrolysis • Exploratory (Prt.) Sacch. • Rheology/CFD Modeling Agricultural Residue Processing (Corn Stover, Wheat Straw, Rice Straw) • Biomass Fractionation • Sugars Production Systems-level demonstration and validation by TBD Systems-level demonstration and validation by TBD Energy Crops (Perennial Grasses, Woody Crops) • CAFI 2 • Feedstock Qualification • Exploratory (Prt.) Sacch. • Biomass Fractionation • Sugars Production Systems-level demonstration and validation by 2010 Pulp and Paper Mill Improvements (Mill Wastes, Wood) • Forest Biorefinery (Hemicellulose Ext.) • New Fractionation Process • for hemiicellulose removal Biomass Program Strategic Goal Cost-competitive biorefinery technologies for the nation’s transportation, chemical and power industries Chemical building blocks from lignocellulosic biomass Fuels, chemicals and power from bio-based sugars and chemical building blocks Element Strategic Goals Sustainably supply biomass to biorefineries Low-cost sugars from lignocellulosic biomass

4. Barriers CommercialSuccess Barriers Price of Sugars from “Cellulosic” Biomass Major General Barriers Feedstock Cost Sugars Composition Sugars Yield Conversion Rate Sugars Quality Capital Investment R&D Technical Barriers Feedstock-Sugars Interface Biomass Pretreatment Enzymatic Hydrolysis Sugars Processing Process Integration • Biomass Recalcitrance • New Pathways • Enabling Tools

5. Overview Budget (FY05) Partners • NREL (Pretreatment and Enzymatic Hydrolysis Task) • Aventine/Purdue University • CAFI Universities • Auburn University • Dartmouth College • Michigan State University • Purdue University • Texas A&M University • University of British Columbia • Neoterics Int’l. • Harris Group Inc. • Novozymes • Genencor Int’l. • Merrick & Co. • University of Louisville

6. Approach • Overall Goal: Enable less severe (less costly) pretreatment and more economical enzymatic hydrolysis/sugar production • Understand how pretreatment alters biomass structure and composition • Assess required enzyme loadings and types • Understand response of feedstock types representing several pathways • Across different pretreatment processes and ranges of severities • Role of non-cellulase enzymes • High solids pretreatment and saccharification 2.4. Targeted Conversion Research 2.1. Pretreatment and Enzymatic Hydrolysis 2.3. Processing Integration

7. Pretreatment and Enzymatic Hydrolysis Projects • Projects Supporting Near Term Biorefinery Opportunities • Bridge to Corn Ethanol Project (Aventine/Purdue) • Hemicellulose Extraction Subtask (NREL) • Pretreatment Effects on Feedstock Structure and Types • Exploratory Saccharification Subtask (NREL) • Feedstock Qualification Subtask (NREL) • Integration of Leading Biomass Pretreatments Project (CAFI 2) • Enzymatic Hydrolysis and High Solids Processing • Enzyme Subcontract Liaison Subtask (NREL) • Enzymatic Hydrolysis Subtask (NREL) • Rheology and CFD Modeling Project (Univ. Louisville)

8. Bridge to Corn Ethanol– Aventine/Purdue • Objective: Demonstrate conversion of residual starch and lignocellulosic carbohydrates in wet mill corn fiber • Work has progressed from bench scale to in-plant pilot-scale testing over 5 years (with technoeconomic analysis guidance) • Simple, low cost approach that readily integrates into existing wet mill • Economic risks mitigated by integrating into existing commercial facility • Bench scale results and economic analysis decision points indicated sufficient potential to proceed to in-plant pilot testing at Aventine • Broad multidisciplinary collaboration involving Aventine, Purdue, NREL, USDA, Illinois Corn Marketing Board

9. Bridge to Corn Ethanol– Aventine/Purdue • Technical challenges focused on process validation at scale and equipment performance • Material handling and heat transfer have proven challenging • Slurry viscosity spikes during initial heat-up, then falls during pretreatment • Process robustness not yet validated for extended continuous operation • Modifications to heat exchanger, pump, and centrifuge underway to enable more reliable operation

10. Forest Biorefinery--Hemicellulose Extraction • Objective: Partially extract hemicellulose prior to chemical or thermomechanical pulping while retaining pulp quality • Solubilize enough sugars to permit economically viable ethanol production • Limit risks by focusing on key issues of hemicellulosic sugar recovery yields and pulp properties • Address other R&D issues later (e.g., oligomer conversion, acetic acid recovery, fermentation) • Initial milestones on sugar yields and potential ethanol economics look attractive under certain scenarios (strongly influenced by assumptions about utility and enzyme costs) • Some issues concerning pulp quality identified (that are being addressed by USDA FPL and academic participants in Agenda 2020 consortium) • Results to inform a go-no go decision for a “Stage 3” cost-shared industry-led consortium project

11. Forest Biorefinery--Hemicellulose Extraction Ferment Ferment Ethanol Ethanol Pre Pre - - Hemi Hemi - - Chip Pile Chip Pile or or Digester Digester cellulose cellulose Chemicals Chemicals Sugars Sugars Digester Digester Paper Products Paper Products Steam Extract Liquor • Completed a series of hemicellulose extractions at various conditions for maple and spruce chips • Preliminary economic analysis for ethanol production conducted • Extracted chips supplied to the USDA’s Forest Product Lab to evaluate pulp quality Recirculating Chip Extractor

12. Exploratory (Pretreatment) Saccharification • Objective: Understand biomass ultrastructure effects • Pretreatment catalyst transport (corn stem as a model) • Identify required enzyme activities as a function of pretreatment approach • Enable a less severe pretreatment that achieves high sugar yields • Highly integrated with other subtasks in Pretreatment & Enzymatic Hydrolysis and Targeted Conversion tasks • Feedstock Qualification subtask generates pretreated samples from different feedstock types across a range of pretreatment pHs/severities • “Joint” milestone with Plant Cell Wall Deconstruction subtask (9/05) • Leveraging “CAFI 2” comparative pretreatment project • Accessing “progressively” pretreated samples to understand how composition and structure change as pretreatment proceeds (effect on enzyme loading and required enzyme activities)

13. Exploratory (Pretreatment) Saccharification Surface Ultrastructure Changes Upon Dilute Acid Pretreatment Enzyme Augmentation Studies on ARP (CAFI) Pretreated Corn Stover Corn stem xylem No pretreatment Corn stem xylem 1.5% H2SO4,150oC, 20 min

14. Feedstock Qualification • Objective: Develop and apply a method for screening pretreatment pH and severity effects across feedstock types • Generate comparative pretreatment reactivity data for stakeholders • Do not attempt to optimize performance of specific pretreatment processes • Select feedstocks (beyond stover) based on “Billion Ton” study results • Switchgrass • Wheat straw • Representative forest biomass feedstock • Complements other activities in Biochemical Platform • CAFI (broad reactivity screening as compared to specific pretreatment process optimization) • Exploratory Saccharification/Plant Cell Wall Deconstruction • Sugar Processing Integration (platform for future integration of feedstock/pretreatment/enzyme combinations)

15. Feedstock Qualification Acidic ( severity) Neutral ( sev.) Alkaline ( severity) Acidic ( severity) Neut. ( sev) Alkaline ( severity) Initial Findings on Switchgrass Across Wide pH Range • Standard methodology for pretreatment and enzymatic saccharification developed • Initial data on switchgrass generated MultiClave 10-Well Reactor Sand Baths for Reactor Heating

16. Integration of Leading Biomass Pretreatments (CAFI 2) • Objective: Develop comparative performance data and process economics on selected leading pretreatment approaches using: • Common feedstocks • Standardized enzymes • Identical procedures for sample analysis • Consistent methods for economic analyses, i.e., for material and energy balancing and process cost estimation • Build off of USDA-funded “CAFI 1” project into new areas • Corn stover and hybrid poplar feedstocks • Enzyme activities and loadings matched to pretreated feedstocks • Hydrolyzate fermentability at relevant sugar concentrations • Rigor of economic models (esp. pretreatment area capital costs) • Generate “progressively” pretreated samples • Facilitate core OBP R&D in the Exploratory Saccharification and Plant Cell Wall Deconstruction subtasks

17. Integration of Leading Biomass Pretreatments (CAFI 2) Comparative Sugar Yields and Process Economics from “CAFI 1” Data AFEX 1.75 Dilute Acid Flow-through Hot Water ARP Lime 1.50 MESP, $/gal EtOH 1.25 1.00 Dilute Acid Hot Water AFEX ARP Lime w/o Oligomer Credit w/ Oligomer Credit Initial Findings from “CAFI 2” Project • Hybrid poplar is more difficult to effectively pretreat and saccharify • Especially for alkaline pretreatments • Commercial xylanase addition can result in higher xylose AND glucose yields at same overall protein loading as “cellulase only” enzyme cocktail • Especially for alkaline and neutral pretreatments • Process modeling updates underway (initial milestone in June, 2006)

18. Enzyme Subcontract Liaison • Objective: Support and validate enzyme cost reduction by enzyme manufacturers (Novozymes and Genencor) • Supply “standard” substrate (dilute acid pretreated corn stover, PCS) • Develop cost metric to translate performance into economic terms, i.e., enzyme cost ($/gallon EtOH) • Experimentally validate improved enzyme performance • Review/Audit achievements in reducing enzyme production costs • Contracts with two enzyme companies reduces risk • Different approaches, different means of achieving cost reduction • Improved enzyme production economics • Improved specific activity • NREL improvements to high solids, dilute acid pretreatment process contributed to enzyme cost reduction

19. Enzyme Subcontract Liaison Example SSF Performance Assay Results -- Improved Preparation Example SSF Performance Assay Results-- Improved Substrate Pretreated Corn Stover (PCS) Substrate Improvements Improved Enzyme Preparation on Pretreated Corn Stover (PCS) 100 100 90 90 80 80 70 70 % Cellulose Conversion 60 60 % Cellulose Conversion 50 50 Benchmark prep 40 Improved PCS 40 30 Improved prep 30 Original PCS 20 Benchmark prep 20 Improved prep 10 10 0 0 0 10 20 30 40 50 60 70 0 10 20 30 40 50 60 70 Soluble Protein Loading (mg protein/g cellulose) Soluble Protein Loading (mg protein/g cellulose) • Enzyme Subcontract Liaison activities completed in FY05 • Verified reduction of cellulase costs to less the $0.20/gallon EtOH (per enzyme cost metric) for both Novozymes and Genencor • 20-30X improvement from starting benchmark

20. Enzymatic Hydrolysis • Objective: Develop processing knowledge to enable high solids enzymatic saccharification • Understand impacts of background sugars and other inhibitors • Characterize rheology and mixing characteristics of high solid slurries to facilitate design of commercial equipment • Identify commercial reactor systems and develop cost information • Will test whole slurry conversion using advanced enzymes • Evaluate solid phase properties during hydrolysis (particle size, crystallinity, rheology, pore size distribution) and relate to kinetics • Investigate fundamental factors affecting rheology • Identify promising commercial reactor systems

21. Enzymatic Hydrolysis High solids processing can significantly reduce capital and operating costs Testing a High Solids Bioreactor (HSBR) and comparing to fed batch solids addition to a stirred tank bioreactor 25% solids before hydrolysis begins

22. Rheology and CFD Modeling—Univ. Louisville • Objective: Use Computational Fluid Dynamics (CFD) modeling to improve design of pretreatment, saccharification, and fermentation reactors • High solids conditions • Changes in insoluble solids level and slurry viscosity as pretreatment and enzymatic hydrolysis reactions proceed • Initial project investigated: • Viscosity of biomass slurries • CFD modeling of pretreatment reactors and stirred tank bioreactors • Detoxification of pretreatment hydrolyzates (activated carbon) • Current project focusing on: • High solids enzymatic processing strategies • CFD simulations of pretreatment/hydrolysis reactors • Measurement of changes in rheological properties

23. Rheology and CFD Modeling—Univ. Louisville CFD Simulations of Stirred Tank Bioreactor at Different Scales CFD Simulations of High Solids Pretreatment Reactor (Varying Screw Conveyor Design) Interrupted Flight Conveyor Conical Bottom-Lift Conveyor

24. Interim Stage Gate Overview • Most Recent Review: • Pretreatment Core R&D Stage Gate Review • June 9-10, 2005 (Golden, CO) • Other Recent Relevant Reviews: • May 2003 “Advanced Pretreatment” Interim Stage A Review • May 2003 “Enzyme Sugar Platform” Interim Stage B Review • November 2003 Office of the Biomass Program Peer Review • May 2004 “Fundamentals and New Concepts” Interim Stage A Review • September 2004 “Sugar Processing Integration” Interim Stage B Review

25. Interim Stage Gate Overview • Pretreatment Core R&D Stage Gate Review • Covered all 8 FY05 projects in Pretreatment Core R&D Area • June 9-10, 2005 (Golden, CO) • Reviewers: • Academia • Sharon Shoemaker – UC Davis • Michael Penner – Oregon State University • Industry • Bob Wooley – Nature Works • Pat Smith – Dow • Government (DOE) • Amy Miranda – Biomass Program (HQ) • Andy Trenka – Biomass Program Project Management Center (Golden) • David Thomassen – Office of Science (HQ)

26. Reviewer Comments—Overall Assessment Strengths • “Goals are relevant, realistic and well managed with stage gate disciplines.” • “Focus on critical issues/challenges. Use of merit-based research. Strong sense of team approach to problem solving.” • “Great researchers, dedicated. Great facilities.” Weaknesses • “Too few resources due to too little funding. DOE is not aggressive enough to terminate projects that don’t meet milestones.” • “Funding inadequate. Not clear that major pilot scheduled for FY08 (?) will have an adequate knowledge base from basic R&D to have the desired impact or to contribute the desired progress.” Suggested additions/deletions to improve the portfolio • “Collaborations for the surface characterization group with academics (to come up to speed fast) would be valuable.” • “Collaborations with knowledgeable groups on the surface characterization lab. Great facility, eager learners and smart people at NREL, but there are experience knowledgeable people elsewhere too, who would love to help.”

27. Reviewer Comments—Specific Projects • Detailed, specific comments were provided to all 8 projects in the Pretreatment Core R&D area • Will soon be available at http://www.eere.energy.gov/biomass/progs/biogeneral/obp_gate/pehindex.html • Specific recommendation to focus on three key areas: • Surface characterization • High solids enzymatic saccharification • Pretreatment and saccharification across feedstock categories

28. DOE Response • Final review panel report from June, 2005 Pretreatment Core R&D Interim Stage Gate Review recently received • 45 pages, with scoring and specific comments on all 8 projects • DOE response to reviewer comments is now underway • Plan to have an official response document completed in January, 2006 • FY06 AOP has been drafted with consideration to initial review panel feedback • A more focused plan in FY06: • Surface characterization • High solids enzyme saccharification • Pretreatment and saccharification across feedstock categories

29. Summary and Future Work Two projects completed in FY05 (no further work in FY06) • Forest Biorefinery—Hemicellulose Extraction (as core R&D activity) • Enzyme Subcontract Liaison FY06 Activities on Specific Projects • Bridge to Corn Ethanol Project (Purdue/Aventine) • Complete pilot testing of system with modified heat exchanger design • Exploratory Saccharification Subtask • Surface characterization: Evaluate lignin re-arrangement effects across different pretreatment approaches (CAFI, Feedstock Qualification, also Processing Integration Task samples) • Enzyme augmentation studies: Effect of specific non-cellulase components on CAFI and Feedstock Qualification pretreated samples

30. Summary and Future Work FY06 Activities on Specific Projects (cont.) • Integrate Leading Biomass Pretreatments (CAFI 2 Project) • Pretreatment and saccharification studies on poplar feedstock • Complete development of updated process economic models • Feedstock Qualification • Complete pretreatment pH and severity screening study of two feedstocks (switchgrass, wheat straw)—ties to FY06 Joule milestone • 3rd feedstock in FY07 (representative forest residue) • Enzymatic Hydrolysis • Continue to develop high solids saccharification (includes advancing rheology and reactor design studies) • Test advanced cellulase preparations under process relevant conditions (high solids, background sugars, hydrolyzate inhibitors) • Rheology and CFD Modeling Project (Univ. Louisville) • CFD simulations of high solids pretreatment and saccharification reactor designs