Biodiesel is produced by reacting vegetable oils or animal fats with a low molecular weight mono alkyl alcohol (in most cases methanol). The so-called transesterification is typically performed at about 60°C in the presence of an alkaline catalyst such as sodium methoxide. For every ten tons of biodiesel produced about one ton of glycerol (or glycerine) is formed as a co-product.

In order to become more competitive and less dependable on politics, the biodiesel industry is looking for cheaper feedstocks, better control over feedstock supplies, improved conversion technology and new ways to increase the value of glycerine.

A significant improvement in conversion technology may come from heterogeneous catalyst systems which give easier catalyst separation, enable higher conversions, and yield a higher quality crude glycerine than current homogeneous alkaline catalysts. Finding new outlets for glycerine is also vital for the biodiesel industry to become more competitive. A promising approach is to convert glycerol to fuel additives, commodity chemicals and polymer building blocks such as 1,2-propanediol; 1,3-propanediol or epichlorohydrin (Pagliaro and Rossi, 2008).