Application of Multistage Steam Distillation Column for Extraction of Essential Oil of Valeriana officinialis L. Cultivated in Iran

Essential oil of valeriana officinialis l. cultivated in iran was extracted using steam distillation technique and then analyzed by gas chromatography and gas chromatography-mass spectrometry. optimization of extraction of essential oil was performed using this technique. the extraction yield results for steam flow rates of 4, 7 and 9 l/min for a packed bed of 100 gram of plant were found to be 0.60, 0.52 and 0.47 percent, respectively. for bed heights of 35, 47.5 and 65 cm and a steam flow rate of 4 l/min the extraction yield was found to be 0.60, 0.36 and 0.24 percent. the results of multistage column for a total of 100 g packed bed and 4 l/min steam flow rate were 0.65, 0.65 and 0.6 for three, two and one stage distillation column, respectively. the oil yield was increased from 0.6 for standard roots to 0.7 for crushing roots.