Sugar Beet Pulp

Ethanol Production from Sugar Beet Pulp

Sugar Beet Pulp To determine the technical feasibility of sequential enzyme treatments to produce separate fermentable Pectinases & sugar streams to increase cellulose loading Hemicellulases rates and ethanol titers from sugar fermentation. Separate sugar streams also may be fermented into Enzymatic Cellulose other higher-value fuels or chemicals. Objective Hydrolysis Cellulases

Arabinose and • Minimal additional costs for harvest, storage or Galacturonic Acid Glucose transportation of sugar beet pulp Sugar beet plant • Elimination of drying and pressing processes for pulp; energy for drying is estimated at $80/ton Escherichia coli Saccharomyces • Low lignin content (<2%) leads to elimination of Fermentation cerevisiae costly thermochemical pretreatment required for Process most other biomass feedstocks Benefits • Sugar beet pulp has a high carbohydrate content Ethanol consisting mainly of cellulose, hemicellulose and pectin Flow chart of ethanol production procedure from sugar beet pulp • Cellulose, hemicellulose and pectin components are readily hydrolyzed by commercial enzymes • Relatively small production scale on a processing plant basis • Relatively low level of cellulose content • Large pectin levels not typical of most lignocellulosic biomass

Challenges • Hemicellulose component has different composition than most biomass feedstocks Working with sugar Bioproduct Research Analyzing carbohydrates beet pulp Laboratory and ethanol

Cellulose • North Dakota and Minnesota produce 15.8 Other million tons of sugar beets per year, which is Ash 15% Glucose more than 50% of total U.S. production 4% 21% • 750,000 dry tons of low-value pulp remain Protein after sucrose extraction in North Dakota and 11% Impact Minnesota Arabinose 21% Pectin Galcturonic • North Dakota and Minnestoa could produce Acid 75 million to 90 million gallons of ethanol per 21% Hemicellulose

year if all carbohydrates in beet pulp (70-75%) Xylose Galactose can be used 2% 5% Sugar beet pulp composition

Scott Pryor, Nurun Nahar, and Rachel Rorick NDSU Dept of Agricultural and Biosystems Engineering www.ndsu.edu/bioopportunities North Dakota State University