1. 2005 OBP Biennial Peer Review Selective Harvest Kevin L. Kenney, Christopher T. Wright Biomass Feedstock Interface Platform November 14, 2005

2. Overview Work Objective Objective – Decrease 2005 cost to $35/dry ton by 2015 for the purpose reducing sugar cost by almost 2 cents per lb, for all Billion Ton Vision Feedstocks Budget – About $2M per year from 2004 -2006 Current Partners – National Laboratories, Universities, Equipment Industry Developing Partners – Agribusiness Commodity Companies, Regional Feedstock Centers Partnerships, Feedstock Interface to Biorefining Partners Note: Sugar conversion cost estimate reductions based on the 2005 post-enzyme subcontract conversion case.

3. Pathway Agriculture Residue Pathway Energy Crops Pathway Pathway Impact: B-Level Milestone – Agriculture residue and energy crop feedstocks available to a biorefinery at $35/dry ton by 2015 C-Level Milestones – Production($10.00), Harvest/Collect($12.50), Storage($1.75), Transport($8.00), Preprocessing ($2.75), System Integration Cost and Quality Improvements (dry biomass first, wet second)

4. Approach 1. DOE Multi-Year Technical Plan Barriers for Feedstock Supply can be grouped into: Cost - $35 / try ton (Operational and Capital Costs) Quality – dockage, composition, conversion efficiency (selective harvest, fractional milling, in-storage fractional conversion) Quantity – biomass types (Billion Ton Study) 2. Develop preprocessing based feedstock supply systems that interface biorefining conversion processes to feedstock resources: Corn Stover Cereal Straw Switchgrass

5. Interim Stage Gate Overview Feedstock Interface Core R&D Ag Residue Processing R&D Energy Crop Processing R&D Feedstock Supply Chain Analysis Harvest & Collection Preprocessing Storage Feedstock Harvest & Collection Assembly System Classification of Biomass Physical Properties in Preprocessing Multi-Component Harvesting Equipment for Sugars Biomass Structure Task Post-Harvest Physiology of Biomass Storage Collection, Commercial Processing, and Utilization of Corn Stover Native Grass Utilization Project Biomass Power for Rural Development Chariton Valley Switchgrass Project UT Switchgrass Project Biomass Supply Systems & Logistics Supply Forecast & Analysis Production Harvesting Collection Storage Preprocessing Systems Integration Transportation Virtual Engineering Tools for Airstream Separation

6. Summarized Reviewer Comments This project was categorized by the reviewers as engineering tool development rather than an R&D project subject to Stage-Gate decision-making. It was observed that the modeling tool(s) were general and that increased focus on biomass and biomass- related applications would be of greater benefit. Recommendation: It is important to identify biomass feedstock characteristics that are important to a biorefinery and show how these tools can help provide feedstock with these characteristics more cheaply/efficiently. The question of where processing is most effectively done needs to be answered. What are the trade- offs on where you effect the separations? These questions need to be answered and the tool tied directly to real-world equipment development.

7. DOE Response Project focused on the relevance to a specific biomass application – selective harvest Identified necessary approach Identified theoretical targets Identified practical targets Developed and applied a computational engineering tool to achieve practical targets Field tested functionality of engineered solution Analyzed residue fractions to establish the value of selective harvest – not according to theoretical separation targets, but according to actual separations accomplished with a grain combine

8. DOE Response Practical Quality Targets Optimize Engineering Design Analysis Results Testing

9. Ongoing Tasks: Feedstock – Conversion Interface (Quality) Anatomical Plant Parts – Theoretical Quality Targets Composition Pretreatment Severity Techno-economic analysis Identifies differential product yield potential and conversion efficiency for plant parts Motivation for selective harvest

10. Ongoing Tasks: Feedstock – Conversion Interface (Quality) Residue Fractions: Chaff (hulls, awns, leaves) Straw (internodal stem, nodes) Practical Quality Targets Hand Fractionation vs. Combine Fractionation Anatomical Fractions: Chaff (hulls, awns, etc.) Leaves Internodal Stem Nodes

11. Ongoing Tasks Objective: Design a baffle to accomplish high-fidelity residue separation Approach: Develop virtual engineering model to design baffle separator by simulating baffle performance to (1) determine the effect of the baffle on the airflow of the combine cleaning system and (2) predict the effectiveness of the baffle in separating the residue streams. Model Components: Combine geometry Baffle design canvas (CAD tool) Embedded, interactive CFD model of the single-phase air flow of the combine cleaning system Computational Engineering Approach

12. Ongoing Tasks Shows that chaff mixing with the straw is not a problem Baffle increased the chaff stream purity from 64% to 93% The 7% straw is result if spearing through the concaves Testing

13. Ongoing Tasks Compositional Analysis Fractionation of residue stream has statistically significant effect on the composition of the the straw and chaff residue streams High-fidelity separation has largest effect on glucan and ash content

14. Ongoing Tasks Straw fraction has highest theoretical ethanol yield No Baffle: no value of selective harvest at this level of fractionation Baffle: 11 gallons of ethanol per dry ton difference between chaff and straw streams – significant differential value of selective harvest Whole stover ethanol yield approximated by dashed line. 0.5% increase for no-baffle straw, 3.3% increase for baffle straw Baffle: Do not loose “higher value” straw in chaff stream Results

15. Summary and Future Work