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 ◦ 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)

Terminology Catalyst- 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 B % biodiesel B20- 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 (H 2 C=C(CH 3 )CONa) ◦ More effective catalyst All have a high pH (caustic) All are dangerous- can burn skin, eyes, respiratory system

Alcohol Choice Methanol (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 (CH 3 CH 2 OH) ◦ 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 respected Store 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 Method 100L, 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 Method 100L, 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% Method 100L, 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 hours for results Performed in plastic pop bottle ◦ MeOH will start to eat plastic after 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 Removal Drain 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 Cautions Biodiesel 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