Why 2g Sugar Process Should Begin with Wet Feedstock Storage Jim Hettenhaus, cea Inc ABFC New Orleans, LA June 2015

INTRODUCTION Stover Harvest Experience Harlan, Iowa –1997 Wisconsin and Illinois FIRES HARVEST RISK FOOTPRINT BALE DETERORIATION DIRT etc Has to be a Better Way! June 2015 cea Inc 2

Bale Loss in Storage Harlan Iowa, 1997 June 20153

cea Inc Bagasse Bale Storage ( ) June 20154

cea Inc Non-Wood Pulp Mill Storage Since 1950s June Dr. Joe Atchison

Wet Storage Basics 30 to 40% DM.... Serious Decomposition ~50% DM (bagasse).... Some Degradation Pile can develop ‘hot spots’ Corrected by moving the material around E. A. Ritter Method (1950).... > 80% DM Circulates liquor to build and saturate pile Added proprietary microbes to ferment sugars Modified Ritter Method... Wild Microbes June 2015 cea Inc 6

Ritter Wet Storage Process Flow June 2015 cea Inc 7 Truck Dump Wash- Shred- (pump ) Wet Storage Pad Pulp Process Feedstock Circulation Liquor Process Water Remove Dirt

cea Inc Multiple Piles Pipe to Top of the Stack June 20158

cea Inc Stover Storage Validation Imperial, NE June USDA Grant

cea Inc Stover Storage Validation Imperial, NE Stable Internal T, Fº~ 700 dry tons, 35’ high June

Wet Storage Composition June 2015 cea Inc 11 Source, Nathan Mosier et al, LORRE, Purdue University Component

Wet Storage Composition Economic Effect June 2015 cea Inc 12 Source, INL and NREL models, '07Change Holocellulose59%68%9% Solubles15%5%-10% More Holocellulose.... $0.20/gal EtOH Less Solubles, $2.25 dt/%.. $22.5/dt Improved Yield & Less Process Waste

cea Inc Wet Storage Removes solubles, volatiles June Source:Tappi

cea Inc Wet Storage Increases Feedstock Yield June Source:Tappi

cea Inc 15 Collection Dry & Wet Feedstock Dry Collection Problems include: Short, weather dependent collection window Fire hazard to transport Wet collection (for Wet Processing) Reduces collection risk Improves scheduling Increases utilization: equipment and labor Adds Water for Process Increases Load Weight Dec 8, 2014

Feedstock Moisture Comparison 6X more water collected 50% M is 3 gal H 2 O/gal EtOH ( The same ratio as present dry mill usage RFA ) Additional 76 MGPY for 30 MGPY Basis: 1 dry ton feedstock, 1100 dt/day, 30 MGPY Dec 8, 2014cea Inc 16 Feedstock Moisture Water lbs Water gal EtOH gal/dt gal H 2 O/ gal EtOH Annual Water (Mgal ) 50%2, %

cea Inc 17 Summary Feedstock Storage June 2015 PARAMETERDRY (Bales)WET (Ritter) Fire Hazard HighNone Dirt & Solubles Remain in BaleRemoved in Pile & Recycled Process Impact of Dirt & Solubles Dust Explosion Hazard Higher Maintenance Process Waste No Dust Less Equipment Wear More Fermentor Utilization Storage Area 10x1x Storage Height Bale Stack LimitsPump Head limit ( >50ft ) Storage Loss >10%<5% Weather Risk Rain, Hot WeatherNone Industry Proven Small, mostly farm useLarge, >100,000 dt/yr (non-wood pulp mills) Project Financing Adds RiskSecure Asset Moisture Limit < 20%Unlimited

cea Inc Future Outlook Collection & Processing Logistics Shrink residue collection area to local dry mill corn supply Move away from dry bale storage One pass harvest: ear, stalk and/or other Wet Storage Water Management Wet Process Water Source, ~200 to 240 gal/dt residue Return Feedstock P, K, soil to field, not to process Farmer Affordable Business Model Expand local Dry Mill with 2G sugars Manage Residue, improved agronomic systems Debt financing possible w/wet storage asset? June

Ethanol Plant Locations RFA Dec 8, 2014 cea Inc 19

Ethanol Plant Locations 1999 Iowa Site Study Dec 8, 2014 cea Inc 20 50, 25 mi radius

Hay Trailer Fire I-25, Colorado Springs-Denver June 2015 cea Inc 21

Recent Corn Stover Fires “Couple Sues DuPont” June 2015 cea Inc 22 Abengoa’s Bales Up in Smoke DuPont Fire & Resulting Lawsuit Nevada, Iowa

cea Inc Dry storage problems Fires ● > 10% yield loss ● 10x space Dust, Dirt ● Liability ● Moisture ● Viable Asset Collection Risk Dry: Field drying risky, schedule uncertain Wet biomass collected in field Downstream Effect: Lower processing cost Less ash, solubles ● Improves feedstock quality More holocellulose ● More production Summarize Value Added Wet Feedstock June

Economic Effect INL Estimate June 2015 cea Inc 24