Enriching volatile aromatic compounds of lavender hydrolats by PDMS/ceramic composite membranes

Lavender hydrolats are of low value due to its low aromatic compound concentration. This work applied polydimethylsiloxane (PDMS) /ceramic composite membranes to enrich volatile aromatic compounds (linalool, terpinen-4-ol, α-terpineol, and camphor) of lavender hydrolats for improving antioxygenic property. The effect of operating conditions on the enrichment was systematically studied. The results showed that the fluxes of the four aromatic compounds increased with the increase of feed concentration in the binary simulation system. The enrichment factor of camphor increased more significantly than other components with the increase of flow velocity and the total flux was basically unchanged in pervaporation. The flux of lavender hydrolats was 254.84 g·m^-2·h^-1, the enrichment factors of linalool, terpinen-4-ol, α-terpineol, and camphor were found to be 5.64, 4.56, 2.59 and 15.31 at 40 °C, respectively. The free radical scavenging rate of enriched lavender hydrolats was significantly improved. This work provides a basis for the recovery of aromatic compounds from lavender hydrates by using PDMS/ceramic composite membranes.