Development of Sweet Sorghum as a Feedstock Crop

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

Delta Bio. Renewables 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

Sweet Sorghum as a Feedstock Crop Component Composition Possible Downstream Products Juice C 6 Sugars Fuels, chemicals, spirits, syrup Bagasse Lignocellulose Feed, cellulosic sugars/fuels, fuel pellets, materials Seed Starch Specialty feeds, sugar products

Processing Learnings (2009 -2014) • 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) • 2 x Roll milling extracts 50% of sugar (mechanical limit) – 3 x 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

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

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

Billet vs. forage harvesting *Sarah E. Lingle, et al, Post-harvest Changes in Sweet Sorghum I: Brix and Sugars, Bio. Energy Research 5 (2012) pp 158 -167.

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