1 NREL/Neoterics Update—CAFI 2 Teleconference Rick Elander National Renewable Energy Laboratory National Bioenergy Center Golden, CO Tim Eggeman Neoterics International Lakewood, CO June 23, 2005 Biomass Refining CAFI

2 Agenda Biomass Refining CAFI Additional enzymatic digestibility data on NREL- generated dilute acid pretreated corn stover and hybrid poplar Process economic modeling plans for CAFI 2 project

3 Additional Digestibility Data Biomass Refining CAFI Dilute acid pretreated stover and poplar samples generated by NREL for CAFI 2 project were also used in core DOE program work at NREL SSF digestibility testing using standard current NREL LAP procedures (some differences from CAFI 2 digestibility protocol) –Enzyme loading on protein (not FPU) basis –Enzyme loading on per g cellulose in pretreated solids (not raw feedstock basis) –Digestibility in SSF mode using washed solids (yield based on conversion in cellulose in pretreated solids to ethanol) Higher severity pretreated Kramer corn stover controls included –More digestible than CAFI 2-generated dilute acid pretreated corn stover

4 CAFI Labeling Nomenclature for Previously Sent Samples Biomass Refining CAFI

Control Control +X Air only Air only + X HV, HT HV, HT + X LV, HT LV, HT + X HV, LTHV. LT Sunds High Severity % Cellulose Conversion HT = High Temperature Wash, LT = Low Temperature Wash HV = High Volume Wash, LV = Low Volume Wash SSF Digestibility of Dilute Acid Sunds Pretreated and Hot Washed Corn Stover to High Severity Pretreated Corn Stover SSF using NREL LAP-008 on washed solids. Enzyme load: 20 mg “Old” Spezyme CP protein/g cellulose Conversion of cellulose entering SSF to ethanol after 168 hr X: Xylanase supplementation: 12 mg “Old” Spezyme CP protein + 8 mg Multifect Xylanase protein/g cellulose Low Severity Low Severity with Hot Wash

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7 SSF Digestibility of Dilute Acid Pretreated Hybrid Poplar in NREL Steam Gun Using Various Enzyme Preparations 190 C, 70 seconds, 0.02 g acid/g dry feedstock Total enzyme load of 20 mg protein/g cellulose in treated feedstock [mix uses 12 mg protein/g cellulose of “new” Spezyme plus 8 mg protein/g cellulose of Multifect Xylanase]

8 Washed Poplar Compared to Steam Gun Pretreated Poplar Sunds Control (Early) Sunds Control (Early) + mix 16/4Sunds Control (Early) + mix 12/8 Air Blow Down only Water Hot-Wash 0.5% EtOH Hot Wash Sunds Control (Mid) Sunds Control (Mid) + mix 16/4 Sunds Control (Mid)+ mix 12/8 0.2% NaOH Hot Wash NaOH and EtOH Hot Wash Steam Gun Pretreated Poplar %Cellulose Conversion SSF Digestibility of Dilute Acid Sunds Pretreated and Hot 20 mg protein (GC 220)/g cellulose in pretreated poplar 16/4 = 16 mg protein (GC 220) + 4 mg protein (Multifect Xylanase)/g cellulose in pretreated poplar 12/8 = 12 mg protein (GC 220) + 8 mg protein (Multifect Xylanase)/g cellulose in pretreated poplar Biomass Refining CAFI SSF using NREL LAP-008 on washed solids. Conversion of cellulose entering SSF to ethanol after 168 hr

9 Process Model - Pretreatment Create Process Model for SO 2 Pretreatment Update Process Models for Other Pretreatments

10 Process Model - Overall NREL 2001 vs. NREL 2002 Model Integrate into Updated Version of NREL’s 2002 Model Front-end Feed Handling –Corn Stover –Poplar State of Technology vs. Market Target

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