Transesterification

From virgin oil to high-tech fuel

The molecular structure of virgin oils precludes their use in conventional combustion diesel engines. Vegetable oils—like animal fats—consist of triglycerides, that is, an ester of the trivalent alcohol glycerol with three fatty acids each.

Replacing the glycerol with methanol transforms the viscons oil into a fuel with excellent properties: biodiesel.

All it takes is a simple chemical reaction called transesterification with methanol and a small quantity of an alkaline catalyst. The most effective catalysts are Evonik’s sodium methylate 30 percent solution in methanol (NM 30) and potassium methylate 32 percent solution in methanol (KM 32).

In addition to biodiesel, the main product, transesterification also yields glycerol as a by-product.

Raw material requirements
Oils (triglycerides):	max. 1% ffa with use of NM30, preferably 0.1%
	max. 3% ffa with use of KM32 or > 1%
	max. 0.3% water, preferably 0.1%
Methanol:	0.1% water

Transesterification

From virgin oil to high-tech fuel

The molecular structure of virgin oils precludes their use in conventional combustion diesel engines. Vegetable oils—like animal fats—consist of triglycerides, that is, an ester of the trivalent alcohol glycerol with three fatty acids each.

Catalysts