Biofuels and their production and consumption have become an inherent part of everyday life worldwide. Any fuel of biological origin can be in principle called biofuel. Biofuels are currently classi?ed as the ?rst generation and the second generation biofuels.
Typical ?rst generation biofuels are bioethanol obtained by fermentation of sugars and biodiesel produced by transesteri?cation of vegetable oils with methanol.
And typical second generation biofuels are fuels mostly called Green Diesel, obtained from triglycerides and related feedstocks.
Green diesel, triglyceride-based hydrocarbons in diesel boiling range, is an attractive alternative to biodiesel—a product of transesteri?cation of vegetable oils, particularly due to its superior fuel properties and full compatibility with current diesel fuels.
Two basic approaches to production of green diesel—(i) hydrodeoxygenation of triglycerides and related compounds over metal sul?de catalysts and (ii) deoxygenation over supported noble metal catalysts are thoroughly discussed from the point of view of reaction conditions, catalyst composition and reaction pathways and products.