biodiesel production: terminology & formulation
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Biodiesel Production: Terminology & Formulation. Barry Latham, M.A.Ed. Biodiesel Production & Curriculum Chemistry & Physics Instructor Chicago Heights, Illinois. Terminology. Biodiesel- fuel made from vegetable oils or animal fats - PowerPoint PPT PresentationTRANSCRIPT
Biodiesel Production: Terminology & Formulation
Barry Latham, M.A.Ed.Biodiesel Production & Curriculum
Chemistry & Physics InstructorChicago Heights, Illinois
TerminologyBiodiesel- fuel made from vegetable oils or
animal fats◦Transesterification (vegetable oils)- the process of
exchanging an alkoxy group of an ester compound with another alcohol
◦Saponification (animal fats)- the hydrolysis of an ester under basic conditions to form an alcohol and the salt of the carboxylic acid
Alcohol- any carbon chain which includes an –OH group◦Methanol (MeOH) or Ethanol (EtOH)
TerminologyCatalyst- a substance that is used in a chemical
reaction, but not consumed◦Potassium Hydroxide (KOH)◦Sodium Hydroxide (NaOH)
FAME- Fatty Acid Methyl Esters (<1 g/mL)◦Biodiesel
B100- 100% biodieselB20- 20% biodiesel, 80% traditional diesel
Glycerin- co-product of biodiesel (~1.173 g/mL)◦Can be made into liquid (KOH) or bar (NaOH) soap
Catalyst Choice Potassium Hydroxide (KOH)
◦ Most used by homebrewers◦ Dissolves faster as flakes than NaOH pellets◦ Glycerin produced can be easily made into liquid soap
Sodium Hydroxide (NaOH)◦ Typically causes more complications with soap formation◦ Used more in the industry◦ Glycerin produced can be easily made into bar soap
Sodium Methacrylate (H2C=C(CH3)CONa)◦ More effective catalyst
All have a high pH (caustic) All are dangerous- can burn skin, eyes, respiratory system
Alcohol ChoiceMethanol (MeOH)
◦ Shortest-chain alcohol◦ Most used by both homebrewers and in the industry◦ Biological effects similar to consuming ethanol, but more
severe Can cause nervous system failure, blindness if ingested or
absorbed through the skin or breathed in great quantities
Ethanol (CH3CH2OH)◦ 2-carbon chain alcohol◦ More restrictions on purchasing, storage and use◦ Higher rate of complications in reaction◦ Can cause inebriation
Both highly flammable and must be respectedStore only as much as you need in a safe area
◦ Obey local fire codes
Safety Issues Methanol
◦ Flammable◦ Can be absorbed through the skin◦ Can cause blindness and death
Potassium Hydroxide◦ Burns◦ Do not allow to touch your skin
Personal Protection Equipment (PPE)◦ Operate in a well-ventilated area◦ Wear safety goggles◦ Protective gloves◦ Do not directly inhale any vapors◦ Tie lose hair back◦ Wear closed toe shoes and long pants
FAME Reaction“Fatty Acid Methyl Ester”
Incomplete Reactions
monoglyceride(2/3 reaction)
diglyceride(1/3 reaction)
Triglyceride(no reaction)
16%BOOST Method100L, 16% MeOH, 2-Stage Process
Perform titration◦ Our oil titrates at 0.44 (August 28, 2008, 34 trials)◦ 0.45 (March 27, 2009, 5 trials)
Add 89% of KOH needed into 16L MeOH◦ Mix thoroughly (will mix overnight)
Add 14L of mixture to heated oil (55°C) Circulate for 1 hr. and settle overnight Add remaining KOH to remaining KOH/MeOH Drain glycerin and add remaining KOH/MeOH
mixture Circulate for 3 hr. and settle overnight Drain glycerin
80/20 Method100L, 18% MeOH, 2-Stage Process
Perform titration◦Our oil titrates at 0.44 (August 28, 2008,
34 trials)Add all KOH needed into 18L MeOH◦Mix thoroughly (will mix overnight)
Add 14.4L of mixture to heated oil (55°C)
Circulate for 1 hr. and settle overnight
Drain glycerin and add remaining KOH/MeOH mixture
Circulate for 3 hr. and settle overnight
Drain glycerin
22% Method100L, 22% MeOH, Single-Stage Process
Perform titration◦Our oil titrates at 0.44 (August 28, 2008, 34 trials)
Add all KOH needed into 22L MeOH◦Mix thoroughly (will mix overnight)
Add all of the mixture to heated oil (55°C)
Circulate for 3 hr. and settle overnight
Drain glycerin
“Dr. Pepper” Method (Small Scale)Single-Stage Process
Is typically used before a large batch
Results indicate how well the method will work on this specific oil
Must be done in the lab, not at oil collection site
Takes 12-24 hours for results
Performed in plastic pop bottle◦ MeOH will start to eat plastic
after 24-36 hours
Methods Summary%MeOH needs to be at least 13%◦More MeOH ensure greater completion of
reaction◦Too much can be wasteful, though
Circulation times can vary◦1-3 hours per batch seems to work for most
Batch sizes of 100L used for simplicity in calculations (scaling up or down)
Glycerin RemovalDrain the bottom layer
of glycerin
Dr. Pepper Method◦ Invert pop bottle and
gently squeeze while using your thumb as a valve
It is better to overflow and lose some biodiesel, than to leave some glycerin in your biodiesel
Biodiesel Use CautionsBiodiesel as an excellent solvent◦All natural rubber will eventually be dissolved
Use Viton, or other synthetic rubber hoses, seals and gaskets
◦Breaks down petroleum “grit” that builds up over time in the combustion chamber Grit is dissolved by biodiesel and can clog fuel and
exhaust filters◦Starting with a lower % of biodiesel slows this
process Can increase % over time while replacing rubber
material and filters