Life cycle assessment of olive pomace valorisation through pyrolysis

A life cycle assessment (LCA) of the olive pomace valorisation by means of a pyrolysis system has been performed. The environmental impacts associated with three different stages were evaluated. The first stage is the olive production, the second stage is the olive oil extraction, where the by-product olive pomace is used as a raw material for the pyrolysis system. An LCA screening of the ecological versus the conventional route has been complementary evaluated. The pyrolysis system yields char, gases and tar, involving the following stages: biomass drying and grinding, pyrolysis, separation of gases and char, gas cooling by consecutively using an air heat exchanger followed of a water one, and the separation of gases and tar. For this study, 14 mid-point and 3 end-point impact categories were selected. The functional unit (FU) of 100 kg olive pomace was considered as an overall bench-mark approach. The obtained results reveal that the most environmental-friendly option was the ecological scenario. Therefore, only the biomass produced by this scenario was considered for a further pyrolysis system. The results showed the pyrolysis system can be considered an ecological tool for the valorisation of olive pomace, using energy-efficient equipment together with the water and air reutilization.