Biogas and Biofuel Synergies

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Biogas and Biofuel Synergies

• Ann C. Wilkie
• Soil and Water Science Department
• University of Florida IFAS
• acwilkie_at_ufl.edu
• 2007 Farm to Fuel Summit
• St. Petersburg, Florida
• July 19, 2007

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Biofuels

• The rapid growth in biofuels production has
  significant impacts that must be managed
• Energy demand
• Wastewater production
• Water and Land use
• Air emissions
• Larger facilities mean increased wastewater and
  by-product volumes

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Bioethanol Production

• Depending on the feedstock and process design,
  ethanol production results in several
  by-products
• Crop residues
• Stillage
• Evaporator condensate
• Condensed solubles
• Spent cake

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DISTILLATION
BIOETHANOL
EVAPORATION
FERMENTATION
EVAPORATOR CONDENSATE
CONDENSED SOLUBLES
WHOLE STILLAGE
THIN STILLAGE
SPENT CAKE
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Stillage Production

• Up to 20 L of stillage per liter ethanol
• Stillage is a very high strength wastewater
• Increased ethanol production requires effective
  stillage treatment and utilization

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Biodiesel Production

• Depending on the feedstock and process design,
  biodiesel production results in several
  by-products
• Crude glycerol
• Washwater
• Press cake
• Crop residues

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TRANSESTERIFICATION
METHANOL KOH
WASTE OIL
CRUDE BIODIESEL
BIODIESEL
OIL CROPS ALGAE
VIRGIN OIL
Oil pressing
Washing
PRESS CAKE
CRUDE GLYCEROL
WASHWATER
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• We have the technology available to meet these
  challenges
• ANAEROBIC DIGESTION

• Anaerobic digestion offers a sustainable
  solution
• Biogas energy for in-plant use / export
• Reduced pollution potential
• Avoids non-energy markets

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Biogas Cycle
Solar energy
Photosynthesis
Biofuel production Animal husbandry Crop
harvesting Industrial processing Human consumption
CO2
H2O
Energy crops
Biofertilizer
Electrical and/or thermal energy
Biogas
Organic wastes
Natural gas pipeline
Anaerobic digestion
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Anaerobic Digestion
Complex Organic Carbon
Hydrolysis
Monomers Oligomers
Acidogenesis
Organic Acids
Acetogenesis
Acetate H2 / CO2
Methanogenesis
CH4 CO2
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LIQUEFACTION PHASE
GASIFICATION PHASE
COMPLEX ORGANIC MATTER
SIMPLE ORGANICS
ACETATE H2 / CO2
ACIDOGENS
METHANOGENS
METHANE and CARBON DIOXIDE
LOW ODOR EFFLUENT
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Biogas as fuel
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GatorGas UF-IFAS Anaerobic Digester (80-90 CH4)
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Water heater at UF-IFAS Dairy powered by manure
biogas
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Cowasaki !!
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DISTILLATION
BIOETHANOL
FERMENTATION
BIOGAS
STILLAGE
ANAEROBIC DIGESTION
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TRANSESTERIFICATION
METHANOL KOH
WASTE OIL
CRUDE BIODIESEL
BIODIESEL
OIL CROPS ALGAE
VIRGIN OIL
Washing
Oil pressing
PRESS CAKE
WASHWATER
CRUDE GLYCEROL
BIOGAS
Anaerobic Digestion
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Biogas from Biomass
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ANAEROBIC DIGESTER
MANURE
BIOGAS
CLOSED LOOP
STILLAGE
BIOETHANOL PLANT
DAIRY / FEEDLOT
FEED
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Biogas power provides

• Energy independence
• Renewable natural gas
• Energy reliability
• Based on locally sourced feedstocks
• Environmental sustainability
• Maximum use of resources

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Biogas and Biofuel Synergies

• Ann C. Wilkie
• Soil and Water Science Department
• University of Florida IFAS
• acwilkie_at_ufl.edu
• 2007 Farm to Fuel Summit
• St. Petersburg, Florida
• July 19, 2007