Development of Sweet Sorghum as a Feedstock Crop Randy Powell, Ph.D. ABFC 2015; New Orleans June 9-10, 2015

Delta BioRenewables LLC (“DBR”) Goal: Re-introduce sweet sorghum as a commercial domestic crop Scalable/replicable technology demonstration since 2009 Focus on mid-size operations: 5-10,000 acres Roll mill juice extraction (20-50 ton/hr scale) Production and R&D Facility Agricenter International; Memphis, TN

ComponentCompositionPossible Downstream Products JuiceC6 SugarsFuels, chemicals, spirits, syrup BagasseLignocelluloseFeed, cellulosic sugars/fuels, fuel pellets, materials SeedStarchSpecialty feeds, sugar products Sweet Sorghum as a Feedstock Crop

Processing Learnings ( ) Billet harvesting preferred for sugar stability – Forage harvesting gives 25+% higher yield (12% bagasse protein) Open-pollinated varieties ~12-16 tpa billet yield (dryland) – Hybrids beginning to exceed 20 tpa Cane preparation unnecessary (softer than sugarcane) 2x Roll milling extracts 50% of sugar (mechanical limit) – 3x Roll milling w/ imbibition extracts ~80% of sugar Juice has high levels of suspended solids – Micronutrients beneficial for downstream fermentations

Sweet Sorghum Product Price Tiers

Ethylene Glycol Coca-Cola “Plant Bottle” Butanol, Isobutanol Gevo (Silsbee, TX), Cobalt BP/DuPont, Tetravitae/Eastman 1,3-Propanediol DuPont/Tate & Lyle (Loudon, TN) Bioisoprene, Butadiene Genencor/Goodyear, Amyris/Michelin Succinic Acid Myriant (Lake Providence, LA) BioAmber/Mitsui, DSM/Roquette, BASF/Purac Leading Chemicals from Sugars

DBR Sweet Sorghum Specialty Products Bulk juice for food use Food & fermentation grade syrups Bagasse pellets & bedding

Billet vs. forage harvesting *Sarah E. Lingle, et al, Post-harvest Changes in Sweet Sorghum I: Brix and Sugars, BioEnergy Research 5 (2012) pp

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