**3.1 Biodiesel**

The European Commission has adopted the Biofuels Directive in 2009, which requires biofuels to contribute 10% of all transport fuels by 2020 [46, 47].

The two main substitutes for conventional fuels are biodiesel and bioethanol. Biodiesel is used in diesel-powered vehicles, while bioethanol is used in gasolinepowered vehicles. The European Union is the major biodiesel producer. USA, Brazil, Argentina, Indonesia and Thailand along with the EU together produce 85% of all biodiesel worldwide. In 2016, 32.6 billion liters of biodiesel were produced globally. Global biodiesel production is expected to reach 39 billion liters by 2024, corresponding to a 27% increase from 2016. It is important to point out that the cost of biodiesel from the first generation biodiesel feedstock is currently 30% higher than of petroleum-based diesel [48]. Furthermore, it is estimated that 60–80% of the biodiesel production cost stems from the cost of raw materials. All this makes use of low-cost second generation biodiesel feedstock which is very attractive alternative [49].
