EFFECT OF MATERIAL LENGTH ON KINETICS OF ESSENTIAL OIL HYDRODISTILLATION FROM LEMONGRASS (Cymbopogon citratus)

The objective of this study is to investigate the effect of material length on the kinetics of the hydrodistillation of lemongrass (Cymbopogon citratus) essential oil with the use of a laboratory-scale hydrodistillation unit. The experimental results showed that the highest yield was taking place at a material length of 10 cm. Based on simultaneous evaporation and diffusion mechanism, the kinetics of lemongrass oil hydrodistillation process can be described mathematically using a two-parameter model. It was found that the parameter relating to the fast oil distillation period (evaporation coefficient) was larger than that of the slow oil distillation period (diffusion coefficient), thus, the evaporation stage was much faster than the diffusion stage. The gas chromatography-mass spectrometry analyses have proved that the material length did not influence the composition of lemongrass oils. The content of the citral as the main component in lemongrass essential oils was found to be more than 80%.