Extraction of Oil from Eucalyptus Camadulensis Using Water Distillation Method

This work was conducted to study the extraction of eucalyptus oil from natural plants (Eucalyptus camaldulensis leaves) using water distillation method by Clevenger apparatus. The effects of main operating parameters were studied: time to reach equilibrium, temperature (70 to100 ° C), solvent to solid ratio (4:1 to 8:1 (v/w)), agitation speed (0 to 900 rpm), and particle size (0.5 to 2.5 cm) of the fresh leaves, to find the best processing conditions for achieving maximum oil yield. The results showed that the agitation speed of 900 rpm, temperature 100 ° C, with solvent to solid ratio 5:1 (v/w) of particle size 0.5 cm for 160 minute give the highest percentage of oil (46.25 wt.%). The extracted oil was examined by HPLC. Keyword Extraction, Water Distillation, Eucalyptus Oil Introduction Eucalyptus oil C10H18O, is one of the most important essential oil. The oil is extracted from fresh and dried leaves, in addition to branch tips [1]. Eucalyptus oil has biological effects, antibacterial, antiviral and antifungal components and long history of use against the effect of cold, influenza, other respiratory infection, rhinitis and sinusitis [2]. Essential oils chemistry is very complex; in nature essential oils themselves have many chemical ingredients. Some of them play a major part and others a minor part. The ingredients found in essential oils are organic due to their molecular structure which is based on carbon atoms held together by hydrogen atoms. Oxygen atoms and sometimes nitrogen and sulphur atoms are also present [3]. They can be essentially classified into two groups: A. Volatile Fraction: Essential oil constituting of 90–95% of the oil in weight. B. Nonvolatile Residue: This comprises 1–10% of the oil, containing, fatty acids, sterols, carotenoids, waxes, and flavonoids. The properties of eucalyptus oil is shown below [4]: Description: Colourless to pale yellow liquid with an aromatic and camphoraceous. odour and pungent, cooling, spicy taste. Molecular formula: C10H18O. Molecular weight: 154. Specific Gravity at 25°C: 0.920 0.925. Refractive Index at 20°C: 1.4550 1.4600. Optial Rotation at 20°C: -0.5° +0.5°. Freezing Point: 0°C +1°C. Iraqi Journal of Chemical and Petroleum Engineering University of Baghdad College of Engineering Extraction of Oil from Eucalyptus Camadulensis Using Water Distillation Method 8 IJCPE Vol.14 No.2 (June 2013) -Available online at: www.iasj.net Boiling Point at 760 mmHg: 176 177°C. Flash Point: 49°C. Melting Point at 760 mmHg: 1.5°C. Solubility: Slightly soluble in water, soluble in: ethanol, ether, chloroform, and hexane. Extraction Essential oils can be extracted using a variety of methods, although some are not commonly used today. Currently, the most popular method of extraction is steam extraction, but as technological advances are made more efficient and economical methods are being developed. These include methods such as solvent extraction, supercritical fluid extraction, and microwave extraction. The suitability of extraction method varies from plant to plant and there are significant differences in the capital and operational costs associated [5]. Principles of Distillation It is imperative to note that a liquid always boils at the temperature at which its vapor pressure equals the atmospheric or surrounding pressure. For any two immiscible liquids, the total number of molecules present in the vapor phase is greater than the number which would be present if either pure liquid were present alone at the same temperature. Hence, the pressure exerted by the vapor mixture will be greater than that exerted by either pure vapor alone [6]. Consequently, the vapor pressure of the whole system increases, that cause to evaporate essential oil at temperature below its boiling point. Thus, any essential oil having high boiling point can be evaporated with steam in a ratio such that their combined vapor pressures equal the atmospheric pressure [3]. Water Distillation In the manufacture of essential oils using the method of water distillation, the botanic material is completely immersed in water and the still is brought to the boil. The main characteristic of this process is that there is direct contact between boiling water and plant material [3]. Distillation offers better conditions for the osmosis of oil, because the higher temperature and the movement of water, caused by temperature and pressure fluctuations within the still, accelerate the forces of diffusion to such a point that all the volatile oil contained within the plant tissue can be collected. A special case of water distillation it uses the practice of returning the distillate water to the still after the oil has been separated from it so that it can be re-boiled. The principal behind it is to minimize the losses of oxygenated components. Practical advantages of water distillation are that the stills are inexpensive, easy to construct and suitable for field operation. These are still widely used with portable equipment in many countries. This method protects the oils so extracted to a certain degree since the surrounding water acts as a barrier to prevent it from overheating [6]. Experimental Work Fresh leaves of Eucalyptus camaldulensis was collected from the gardens of Baghdad University, the leaves were taken to laboratory and cut out by a pair of scissors to small part. The schematic diagram of the equipment used is shown in figure 1. The Clevenger consists of a main tube combined with condenser and graduated tube with glass stopcock. A return tube for the aqueous part of the distillate connects the bottom of the measuring tube and the main tube. Eighty grams of fresh and clean Basma A. Abdul-Majeed, Asrar A. Hassan and Badoor M. Kurji -Available online at: www.iasj.net IJCPE Vol.14 No.2 (June 2013) 9 Eucalyptus leaves were placed into the three necked round extraction n flask and soaked with water. Clevenger apparatus was linked to the flask as shown in figure 2. The flask was heated using heating mantel. Water and leaves, were mixed and allowed to boil. Water and extracted eucalyptus oil evaporate. The vapour mixture condensed using reflux condenser, from condenser distillate water and oil flow in to gradated tube; as the oil is not miscible with water it may be easily separated and started accumulating and distillate water returning to the flask, after the oil has been separated from it, so that can be re-boiled. The oil was allowed to stand for sufficient time, to be clear and then it was collected and stored in dark glass vial in a refrigerator until it has been tested. Fig. 1, laboratory glassware Clevenger Fig. 2, Photographic representation of water distillation unit Results and Discussion Effect of Extraction Time The obtained results are plotted in figure 3. The effect of extraction time on oil extraction was studied until the equilibrium was reached, of particle size 0.5 cm at 100°C with solvent (distilled water) to solid ratio 5:1(ml/g) and agitation speed 300 rpm. Fig. 3, Effect of extraction time on oil extraction by water distillation Operating conditions (P.S.=0.5 cm, S.R. =5/1(ml/g), A.S.=300 rpm, T=100°C) The results in figure 3 shows, that extraction of oil increased with time. It is also can be observed that the rate of extraction is fast at the beginning of the extraction but gets slow gradually. The reason is that when the meal is exposed to the fresh solvent, the free oil on the surface of particles gets extracted quickly inducing a fast increase in the extraction rate. Furthermore, since the oil concentration is low in the solvent at the beginning of the extraction process, the oil diffuses quickly from the meal to the liquid phase due to the mass transfer effect. As the time passes by, the concentration of oil increases in the solvent resulting in a decrease in the diffusion rate. When the maximum amount of extractable oil is obtained, the oil yield level remains constant even by extending the extraction time; it reaches equilibrium [7]. This results are in agreement with the results which 0 5 10 15 20 25 30 35 40 0 100 200 300 % O il y ie ld