Life cycle assessment of flax and camelina for biodiesel production in Sicily (Southern Italy)

The use of renewable vegetable oils derived from oilseed crops could have serious environmental impacts especially regarding competition for land and emissions in air and water. The environmental performances of Linum usitatissimum L. (Flax) and Camelina sativa L. (Camelina) oilseed crops for biodiesel production has been assessed by means of Life Cycle Assessment (LCA) approach, considering three steps: i) the cultivation, ii) oil seeds transport to pressing plant and seed pressing, iii) biodiesel production from vegetable oil by transesterification. For the biodiesel from flax and camelina, more than 90% of the environmental impact is related to seed production, followed by the transesterification of raw vegetable oil and seed pressing at lab scale. The environmental performances are worst for the camelina mainly due to a lower seed yield. Nevertheless, these differences are slightly reduced thanks to the higher HHV (Higher Heating Values) of the camelina biodiesel. For both the biodiesel, the main environmental hotspots are: the production of factors production, the nitrogen emissions associated with the application of fertiliser and the mechanisation of the field operations (in particular soil tillage and sowing) and the emission of N and P compounds related to fertilisers application. In comparison with rapeseed (from data of Ecoinvent 3), the biodiesel from flax and camelina shows a higher environmental impact due to the higher consumption of fertilizers in rapeseed crop management.