THE EFFECTIVE DIFFUSIVITY OF CLOVE(Eugenia caryophyllus) ESSENTIAL OIL IN PRESSURIZED CO2

Abstract

The effective diffusivity of clove essential oil in subcritical liquid CO2 was estimated. The experimental apparatus employed was a fixed-bed extractor. The fixed bed was formed with grounded (mesh -32 + 65) and compacted clove buds which were considered a solid element. The effective diffusion coefficient was evaluated by fitting the experimental concentration profile to the unsteady state mass balance equation for unidirectional diffusion in a finite solid medium. The diffusion coefficient was related to the concentration of oil in the solid by an exponential function. The estimated values of the effective diffusion coefficient varied from 3.64 to 5.22x10-10 m2/s. The average relative errors were lower than 3.1%.<br>O coeficiente de difusão efetivo do óleo essencial de cravo-da-índia em CO2 líquido subcrítico foi estimado. O equipamento experimental usado foi um extrator de leito fixo. O leito fixo foi formado por cravo-da-índia moído (mesh -32 + 65) e compactado, sendo assim considerado como um meio sólido. O coeficiente de difusão efetivo foi estimado pelo ajuste do perfil de concentração experimental à equação de balanço de massa em estado transiente, para difusão unidirecional em um meio sólido. A dependência do coeficiente de difusão com a concentração de óleo no sólido, foi descrita por uma função exponencial. O coeficiente de difusão determinado variou de 3,64 a 5,22x10-10m2/s. Os erros médios relativos foram menores do que 3,1%

Separation and analysis of the major constituents of cloves by micellar electrokinetic chromatography

“…As an example, the eugenol content of clove oil is reported to be about 94% [17] according to some sources, and about 50% [20] according to other sources. For this reason, reliable analytical methods are clearly needed.…”