John Deere Visit July 28, 2000

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Kansas State University
Biodiesel Production and Handling
Wenqiao (Wayne) Yuan, Ph.D. Assistant
Professor Department of Biological and
Agricultural Engineering February 6, 2007 at KFB
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What is biodiesel

• Biodiesel
• Is a renewable fuel
• Is not straight vegetable oil (SVO)
• Is not waste vegetable oil (WVO)
• Is not a mixture of oil/fat with an alcohol
• Is not a blend with diesel fuel
• ASTM D6751

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Transesterification
A simplified representation of biodiesel
production Transesterification
(96 g)
(888 g)
(92 g)
(884 g)
100 lbs of oil 10.86 lbs of methanol -gt 100.4
lbs of biodiesel 10.4 lbs of glycerol
100 lbs of oil 21.72 lbs of methanol -gt 100.4
lbs of biodiesel 10.4 lbs of glycerol
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Issues Related to Transesterification Process

• Feedstock Issues
• FFA
• Water
• Process Issues
• Type of Alcohol
• Molar Ratio
• Catalyst
• Reaction time temperature
• Agitation

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Feedstock Issues

• 1. Free Fatty Acids (FFA)
• Free Fatty acids in the oils react with alkaline
  catalyst to form soaps.
• R-OH KOH K-OR H2O
• (FFA) KOH (Soap) water
• It results in loss of catalyst and reduction in
  yield

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Feedstock Issues (cont.)

• 2. Water
• Water deactivates the catalysts. Drying of
  oil is required.
• Water hydrolyses fats to form free fatty
  acids.

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Process Issues
Type of Alcohol

• Methanol, Ethanol, Butanol etc
• Methanol commercially used
• In methanolysis, emulsion forms and separated
  into lower glycerol portion and upper ester
  portion. Reaction time is small
• In ethanolysis, emulsions are stable and requires
  more complicated separation and purification
  process. Reaction time is large
• Typical alcohol TG molar ratio is 61 for base
  catalyzed reactions.

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Process Issues (cont.)
Catalyst used

• NaOH (Sodium hydroxide)
• High purity
• KOH (Potassium hydroxide)
• Need more
• Glycerol waste can be disposable
• H2SO4 (Sulfuric acid)
• Pretreatment of high free fatty acid oil
• Direct acid catalyzed reaction (not common)

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Process Issues (cont.)
Reaction time, temperature agitation

• Transesterification reaction will proceed at
  ambient (30C) temperatures but needs 4-8 hours
  to reach completion.
• Reaction time can be shortened to 2-4 hours at
  40C and 1-2 hours at 60C.
• Higher temperatures will decrease reaction times
  but require pressure vessels because methanol
  boils at 65C.
• Better agitation should be adopted to accelerate
  reaction.

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Batch, Base Catalyzed Process
Alcohol
Water
Water
TG
Ester
Biodiesel
Alcohol Catalyst
Dryer
Alcohol
Wash Water
Water
Acid
Batch Reactor
Crude Glycerol
Neutralized Glycerol
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30 gallon biodiesel unit
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Appleseed style biodiesel processor (design by
Maria Alovert). Uses old electric water heater as
main unit
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600 LITERS/DAY BIODIESEL UNIT
Control Panel
Motor Gear Box
Skid
Oil Tank
Methaoxide Vessel
Washing Vessel
Vacuum Drier
Separating Vessel
Reaction Vessel
Development Cost US 7000
Motor Gear Pump
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High FFA Feed Stocks

• Biodiesel feed stocks are classified by the
  amount of free fatty acids they contain
• Refined vegetable oils lt 0.05
• Crude vegetable oil 0.5-5
• Used Cooking Oil 2-7
• Animal fat 10-30
• Price decreases as FFAs increase but processing
  cost also increase
• Base Catalyzed Reaction not suitable for high FFA
  feeds because of soap formation!

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Acid Catalyzed Processes

• Acid catalyzed processes are used for direct
  esterification of free fatty acids in a high FFA
  feedstock
• Limitations
• Water formation by
• FFA methanol gt methyl ester water
• High alcohol FFA ratio required about 401
• Large amounts (5 to 25 ) catalyst may be required

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Preferred method for High FFA feeds Acid
Catalysis followed by base catalysis

• Use acid catalysis for conversion of FFAs to
• methyl esters, until FFA lt 0.5.
• Acid esterification of FFA is fast (1 hour) but
  acid catalyzed transesterification is slow (2
  days at 60C).
• 2. Then, add additional methanol and base
  catalyst to transesterify the triglycerides.

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Air
Biodiesel Unit 1tpd Capacity
SVO
SV2
P1
Motor
Methanol H2SO4
Design by DCE
Vegetable Oil Storage Tank 1500 Kg
Reactor 600 Ltrs.
Settling Tank 1000 Ltrs.
Vaccum Drier
SV2
P3
P2
Motor
Methanol KOH
SV3
Storage Tank 500 Ltrs.
Biodiesel Storage Tank 1000 Ltrs.
P6
P8
Vaccum Drier
P7
P5
Transesterification Reactor, 500Lts./Charge
P4
Washing Column 500 Ltrs./ Charge
Glycerol Storage Tank 500 Ltrs.
Separating Column 500 Ltrs./ Charge
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What you need to know about biodiesel
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Less energy content

• Less energy content
• 8 less energy per gallon
• 12.5 less energy per pound
• 8 less in power and torque
• 8 more fuel consumption or less MPG
• For B20, see 1 to 2 reduction in power
• For B5 or lower, no noticeable differences

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Stability issue

• Long term storage or aging
• Stability at elevated temperature and/or
  pressures as the fuel is recirculated through an
  engines fuel system
• The higher the level of unsaturation, the worse
  stability is
• Heat and sunlight will accelerate oxidation
• Certain metals such as copper, brass, bronze,
  lead, tin and zinc will accelerate the
  degradation process
• Keeping oxygen from the fuel reduces or
  eliminates fuel oxidation
• Antioxidants, whether natural or incorporated as
  an additive, can increase storage life or
  stability
• Fuel turn over between 2 and 4 months has no
  problem
• NBB recommends 6 month storage life for B100

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Cleaning effect

• Biodiesel has a tendency to dissolve the
  accumulated sediments in diesel storage and
  engine fuel tanks, which can plug fuel filters
  and even burst fuel filters to send all the
  sediment through the fuel system
• B35 and above has much greater cleaning effect
• Even if B20 is fine, it does not justify higher
  blending level
• Dont leave biodiesel on vehicle body

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Material compatibility

• B100 will degrade, soften, or seep through some
  hoses, gaskets, seals, elastomers, glues, and
  plastics with prolonged exposure
• Nitrile rubber compounds, polypropylene,
  polyvinyl, and Tygon materials are particularly
  vulnerable to B100
• Contact OEM or dealership before you use B100
• Brass, bronze, copper, lead, tin and zinc may
  accelerate the oxidation of diesel and biodiesel
• B20 is normally ok

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Gelling
(C)
No. 2 diesel
B5 is ok
B20 is problematic
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Biodiesel cold flow

• Blending biodiesel with diesel is most effective
• Most cold flow additives have a limited
  effectiveness on B100, but work with varying
  degrees of effectiveness with B20
• Mix with No.1 diesel fuel in winter
• Use less saturated feedstock in winter
• Use B10 or less in winter, but B30 or more in
  summer
• Lab testing should be done

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Summary

• Base catalyzed or acid pretreated and then base
  catalyzed methods are commonly used to make
  biodiesel
• What you need to know about biodiesel

• About 8 power and MPG loss
• Stability issues
• Cleaning effect
• Material compatibility
• Cold gelling

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Thank you!

• Questions or Comments?

Wenqiao (Wayne) Yuan Dept of Biological and
Agricultural Engineering Kansas State
University Office 785-532-2745 Email
wyuan_at_ksu.edu
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Feedstocks used

• Soybean oil, rapeseed oil, canola oil, cottonseed
  oil, corn oil, mustard oil, palm oil, etc
• Restaurant waste oils such as frying oils
• Animal fats such as beef tallow or pork lard
• Trap grease (from restaurant grease traps), float
  grease (from waste water treatment plants), etc

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Alcohol used

• Methanol
• Less expansive
• Lower boiling point (64.7C)
• Toxic
• Non-renewable
• Ethanol
• More expensive
• High boiling point (78.4C)
• Non-toxic
• Renewable

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Background
How is biodiesel used?

Pure biodiesel-B100 -In European Union
Countries
Blends (85)-B85 -Used in a power genset
Blends (20)-B20
As an additive-B2 -North Dakota and
Minnesota
Others solvents and paint remover
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Background
Any problems with biodiesel?

• Higher cost
• Lower energy content
• Weight base 12.5 lower, Volume base 8
  lower
• Worse cold flow properties
• Higher NOx emissions

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Biofuel research opportunities

• In the U.S.
• Advanced Energy Initiative 22 increase in clean
  energy research funding
• In Kansas state
• Kansas alternative fuels bill SB 387 has been
  introduced in the state Senate by the Committee
  on Agriculture to require the mandatory use of 2
  biodiesel in all diesel fuel sold for IC engines
  by Jan 1, 2010

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Why care about biodiesel?
Biodiesel Benefits the U.S. Farm Economy
An example of Kansas state once bill SB387 passed
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Biodiesel benefits the U.S. economy

• An example of biodiesel impact on Kansas state
  economy based on an annual diesel consumption of
  800 million gal.
• The U.S. consumes about 60 billion gallons of
  diesel per year.

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Cost analysis of biodiesel (analysis from Dr.
Jon Van Gerpen)
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Cost analysis of biodiesel (analysis from Dr.
Jon Van Gerpen, Cont.)
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Example Farmer Benefits of Biodiesel Use

• Assumptions
• A farmer wants to support biodiesel prod./use, so
  he/she uses B5 on-farm at 0.06 more per gal.
• Soybean increases 0.05/bu because of biodiesel
  use
• 30 bu/ac average soybean yield
• Average of 12.5 gallons of diesel used per acre
• Gain or Loss Additional Revenue Additional
  Cost
• Per Acre
• 30 bu/ac 0.05/bu 12.5 gal/ac 0.06/gal
  0.75
• On All Arkansas Soybean Acres with B5
• 2.1 million increase in net returns for AR
  farmers

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Example Farmer Benefits of Biodiesel Use (cont.)

• The break-even soybean price increase is 2.5
  cents/bu
• A less than 1 increase in soybean prices
  justifies the use of a biodiesel blend fuel.
• This price increase depends on growth of the
  biodiesel industry from
• Voluntary use (e.g. farmers using their own
  product)
• Mandatory use (e.g. a federal renewable fuels
  standard)

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Example Farmer Benefits of Biodiesel Use (cont.)

• If all soybean acreage in AR was grown using B5,
  over 2 million gallons of biodiesel would be
  demanded
• Would increase soybean demand 1.45 million
  bushels.
• The total amount of diesel used on-farm in AR
  2001 was 136.1 million gallons. If B5 was used
  this would require 6.8 mil gal of biodiesel
• Would increase soybean demand 4.86 mil. bushels

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Biodiesel Availability in Arkansas

• Morrilton Agri Coop Supply
• Neat (100) biodiesel sells for 1.92/gallon
• Conventional off-road diesel sells for 0.799
• B5 (5 biodiesel) costs 0.056 more per gallon
  than conventional diesel (0.950.7990.051.92
  0.855)
• World Energy Alternatives will ship to a customer
  or through existing fuel suppliers
• Some premium diesel contains small amounts of
  biodiesel
• CENEX Ruby Fieldmaster, Roadmaster, and
  Wintermaster
• No current biodiesel production in AR

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Alkali-catalyzed transesterification
Settling for 8 hours for glycerol separation
Agitated for on hour at 60C
Vacuum stripping
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Molecular structure
Fats and oils have quite big molecules with a
spinal of glycerol on which are bond three fatty
acid rests.
By the transesterification, the fatty acid rests
are removed from the glycerol and each is bond
with methanol.
The products are one mole glycerol and three mole
of fatty acid methyl ester.
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Catalyst?
Chemical marriage brokers The presence of a
catalyst facilitates reactions that would be
kinetically impossible or very slow without a
catalyst