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 FacilityAgricenter International; Memphis, TN

Component Composition Possible Downstream Products

Juice C6 Sugars Fuels, chemicals, spirits, syrup

Bagasse Lignocellulose Feed, cellulosic sugars/fuels, fuel pellets, materials

Seed Starch Specialty feeds, sugar products

Sweet Sorghum as a Feedstock Crop

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)• 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 GlycolCoca-Cola “Plant Bottle” Butanol, Isobutanol

Gevo (Silsbee, TX), CobaltBP/DuPont, Tetravitae/Eastman

1,3-PropanediolDuPont/Tate & Lyle (Loudon, TN)

Bioisoprene, ButadieneGenencor/Goodyear, Amyris/Michelin

Succinic AcidMyriant (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) pp158-167.

Support and Collaboration