SWEET POTATO PRODUCTION FOR ETHANOL

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SWEET POTATO PRODUCTION FOR ETHANOL
FEEDSTOCKS FOR BIOENERGY IN FLORIDA THE SWEET
POTATO
GEORGE HOCHMUTH hoch_at_ufl.edu
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SWEET POTATO Ipomoea batatus
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SWEET POTATO

• CONVOLVULACEAE-MORNING GLORY FAMILY
• TOP TEN FOOD CROP IN WORLD
• OFTEN CALLED YAM IN THE TRADE
• VARIOUS TYPES, COLORS, USES
• HIGH IN CARBOHYDRATE CONTENT

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SWEET POTATO PRODUCTION IN THE USA
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North Carolina Sweet Potato Commission
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SYNOPSIS OF SWEET PRODUCTION PRACTICES
TRANSPLANTS
NEWLY TRANSPLANTED FIELD
TRANSPLANT BEDS
MECHANICAL TRANSPLANTER
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SWEET POTATO PRODUCTION
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SYNOPSIS OF SWEET PRODUCTION PRACTICES
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SWEET POTATO COSTS OF PRODUCTION Alabama, 2005
(/acre)

• CUSTOM 20
• FERTILIZER 204
• HERBICIDE 35
• INSECTICIDE 85
• PLANTS 230
• HARV, PACK, SALES 1550
• LABOR 450
• FUEL, REPAIR 60
• INTEREST 30
• FIXED 80
• TOTAL COSTS 2744

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SWEET POTATO AS A FEDSTOCK FOR FUEL ENERGY
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ALCOHOL PRODUCTION WAS 40 TO 200 GREATER PER
UNIT PRODUCTION AREA WITH SWEET POTATO THAN OTHER
CARBOHYDRATE CROPS SUCH AS JERSULEM ARTICHOKE,
BEET, AND IRISH POTATO

• Mays et al., 1990. Fuel production potential of
  several horticultural crops. Adv. In New Crops.
  Timber Press.

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SWEET POTATO ROOTSSOME REPORTED CHEMICAL VALUES

• 20 DRY MATTER
• SUCROSE, GLUCOSE, FRUCTOSE (4, 3, 2 FR WT)
• NEAR 40 TOTAL SUGAR BY DRY WEIGHT
• 20 TO 25 STARCH BY FRESH WEIGHT
• 42 grams ETHANOL (200 proof) FROM 400 grams of
  fresh sweet potato
• 430 gals of 200 proof ethanol from acre (500
  bushels) of Georgia Red sweet potato
• Texas Tech Univ., Univ. Georgia, North Carolina
  State Univ.

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SOME ALCOHOL YIELDS FROM VARIOUS CROPS
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SWEET POTATO COSTS OF PRODUCTION (/ACRE)

• FOOD (AL, 2005) FUEL (EST.)
• CUSTOM 20 20
• FERTILIZER 204 175
• HERBICIDE 35 35
• INSECTICIDE 85 40
• PLANTS 230 230
• HARV, PACK, SALES 1550 300
• LABOR 450 100
• FUEL, REPAIR 60 40
• INTEREST 30 25
• FIXED 80 50
• TOTAL COSTS 2744 1015

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SWEET POTATO POSITIVE ATTRIBUTESAS A FUEL CROP
IN FLORIDA

• SUBTROPICAL CLIMATE-CAN GROW ANYWHERE
• RELATIVELY LOW INPUTS
• CAN BE HANDLED MECHANICALLY
• HIGH YIELDS OF ALCOHOL
• CAN BE STORED FOR SHORT PERIODS
• COSTS OF PRODUCTION CONSIDERABLY LESS THAN FOR
  FOOD CROP-PERHAPS

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WHAT IS NEEDED TO EVALUATE POTENTIAL OF SWEET
POTATO AS A FUEL CROP

• EVALUATION OF VARIETIES FOR YIELD
• INDUSTRIAL VARIETIES-GREATER STARCH CONC.
• MEASURE PRODUCTION, HARVESTING COSTS
• EVALUATE ALCOHOL YIELD AND CONVERSION COSTS
• EVALUATE TOTAL ECONOMIC PICTURE, PRODUCTION,
  TRANSPORT, CONVERSION, ETC.
• EVALUATE OVERAL IMPACT ON FOOD SYSTEM,
  ENVIRONMENT
• DEMONSTRATION PROGRAM

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GO GATORS !!!