Triglycerides in the extracted oils are made to react with methanol with the addition of a catalyst in order to hasten the process helps break off the fatty acids away from glycerin and converting them into esters. After passing the raw materials through the vegetable oil production line, the resulting mixture must be washed thoroughly to remove waxes and residual catalysts. After this stage, the outcome of the process would be pure esters whose properties are like those of petroleum diesel. It can thus be run on automobile engines without further modification. The viscosity of biodiesel obtained from vegetable oil bears close similarity to that of conventional petroleum diesel.