Life cycle energy and carbon emissions of essential oil extraction from Rosemary

The search for essential oils from aromatic plants has been growing worldwide due to its potential applications in the food, cosmetic and pharmaceutical industries. This work aims to evaluate the life cycle’s primary energy and carbon emissions of essential oil extraction from Rosemary grown in Portugal, following the LCA methodology. Two different functional units, 1 g of aromatic extract and 1 g of α-pinene, were selected for the study. Life cycle inventory data were mainly obtained from lab scale experiments, comparing three essential oil extraction processes, based on hydro-distillation (HD), HD followed by lyophilization (L) and supercritical fluid extraction (SFE). Results show that for the fresh samples, SFE is the best extraction method, with 290 MJ and 15 kg CO2-eq of energy and carbon emissions per 1 g of aromatic extract, while for dried samples the HD is preferable, with respectively 166 MJ and 8 kg CO2-eq per 1 g of aromatic extract. On the other hand, for obtaining 1 g α-pinene the HD is the best method with 465 and 1398 MJ of energy and 23 and 69 kg CO2-eq of carbon emissions, for respectively the fresh and dried samples.