Catalyst

Catalysts

Sodium Hydroxide and Potassium Hydroxide are popular catalysts for home biodiesel production. They are mixed with Methanol to form a Methoxide.

Sodium Hydroxide (NaOH)

• inexpensive
• harder to dissolve into solution with Methanol
• solid Glycerol by-product
• accurate titration required to avoid making excess soap

Potassium Hydroxide (KOH)

• more costly
• easy to dissolve into solution with Methanol
• liquid Glycerol by-product
• forgiving with inaccurate titrations

Storage and handling

Both catalysts should be kept in a dry, sealed airtight container away from the reach of children.

Protective gloves and eye equipment must be worn during handling, as both are strong bases and will dissolve flesh into soap.

Care should be taken with "flake" products to avoid inhalation.

Never add Methanol to the catalyst - always dissolve the catalyst into the Methanol.

Methoxide mixing is an exothermic reaction, so care must be taken to release pressure during mixing, and a concentration of 100g catalyst in 1l of Methanol should not be exceeded, to prevent the Methanol boiling.