Extraction of essential constituents from effluent of hydro-distillation of fennel and investigation of hydrodynamic parameters using a rotary disc column (RDC)

There are different methods for the extraction of essential constituents from medicinal and aromatic plants; however, extraction with the aid of hydro-distillation is a common and feasible technique. In hydro-distillation, essential oils are extracted by water (solvent) and heat (process accelerator). Generally, this approach allows the extraction of essential constituents from generated wastewater. In this study, fennel, with antioxidant and antibacterial characteristics, was used for the extraction of essential oil. The major components found in fennel essential oil include Anisole, Estragole, Fenchone, and Limonene. The mass transfer of the extraction process in the RDC column was investigated with Anisole as the solute. The solvent used in this study was n-hexane (dispersed-phase). The effects of three parameters including dispersed-phase flow rate (3.8, 4.1, and 35 cc/min), nozzle size (1 and 1.5 mm), and rotor speed (75,125, and 175 rpm) on the holdup and mean drop size were assessed. For mass transfer evaluation of anisole, response surface methodology (RSM) was adopted. It was observed that at the optimum point, the amount of efficiency based on Anisole was 52%.