Safe Chemical Handling in Biodiesel Production


Biodiesel is a relatively safe product. It is considered nonflammable and biodegradable. However, the components to make biodiesel can be hazardous in some situations. Biodiesel is made by reacting vegetable oil or animal fat with an alcohol (methanol or ethanol) and a catalyst (sodium hydroxide or potassium hydroxide). Sulfuric and hydrochloric acids are also used in biodiesel production. Methanol, the catalysts, and the acids are toxic chemicals.

Methanol is colorless and tasteless and can cause blindness or death if …

Handling Strong Bases in Biodiesel Production

Sodium and Potassium Hydroxides/Methoxides

Used to catalyze the transesterification reaction, sodium and potassium hydroxide are extremely corrosive.

The hydroxides are dry flakes or pellets and must be dissolved in methanol, which produces “methoxides” concentrated in methanol. The dust from the hydroxides is an airway irritant and will burn unprotected skin and eyes, especially when handled manually. Dissolving the hydroxides in alcohol is an exothermic reaction and can generate a considerable amount of heat. Stirring the liquid in an open container …

Handling Strong Acids in Biodiesel Production

Sulfuric and Hydrochloric Acids

Acids may be used in treating high free fatty acid (FFA) feedstocks, neutralizing base catalyst and splitting soaps in the washing process, and/or in treating the crude glycerin by-product. Acids are colorless and can be extremely damaging to all body tissue. Acids cause rapid tissue destruction and serious chemical burns. Their vapors can cause eye, nose, and throat irritation; shortness of breath; pulmonary edema; or other serious ailments. Workers should wear acid-resistant protective clothing and gloves, …

Handling Alcohols in Biodiesel Production

Methanol and Ethanol

Methanol is the driving force behind the transesterification reaction. Methanol is colorless and tasteless, with a mildly sweet odor, and is a toxic chemical. It can enter the body through inhalation, direct skin contact, or accidental swallowing. It can cause blindness or death. Because it is eliminated from the body slowly, it is considered a cumulative poison, and repeated exposure could present long-term health hazards.

Personnel working with methanol should wear protective clothing (pants, long sleeves, coveralls) …