A number of different catalyst systems can work for the conversion of oils or fats (fuelstock) into biodiesel. Among the options are either acidic or basic homogeneous catalysts or acidic or basic heterogeneous catalysts. Homogeneous catalyst systems require catalysts which are liquids and heterogeneous catalysts are solids.

Basic catalyst:

KOH – Potassium Hydroxide

NaOH – Sodium Hydroxide

Choline Hydroxide – phase transfer catalyst

TMAH – phase transfer catalyst

Acidic Catalyst:

Excess methanol and sulfuric acid H2SO4

Solid resin acids