Py-GC/MS and pyrolysis studies of eucalyptus, mentha, and palmarosa biomass

With the extraction of essential oils, a large amount of residual biomass is produced and they can be a good source of functional chemicals/energy. In this study, Py-GC/MS and slow pyrolysis of eucalyptus, mentha, and palmarosa were performed at various temperatures ranging from 300–450 °C to understand the distribution and characterization of the products. Under slow pyrolysis conditions, maximum bio-oil yield for eucalyptus (50.6 wt.%) and palmarosa (42.6 wt.%) was observed at 400 °C; however, for mentha (39.5 wt.%), it was observed at 450 °C. From bio-oil analysis, mentha showed a maximum area% of carbonyls (47.72%); however, phenolics were present in maximum area% in eucalyptus (63.82%) and palmarosa (46.39%). Eucalyptus bio-char showed a higher surface area as compared to the other bio-chars.