Application of Multistage Steam Distillation Column for Extraction of Essential Oil of Rosemarinuse officinialis L

In this work, a new process design and clean production to increase the yield of steam distillation of rosemary essential oil was studied. For extraction of essential oil, a packed bed of rosemary was exposed to the steam flow. For improving the total yield, multistage bed column was used. The effects of steam flow rate, height of plant bed, multistage beds and time of extraction on yield and composition of the oil were studied. Also, trend of three major components of the oil during different extraction times and conditions were observed. We determined minimum steam to be passed through the packed bed so that there is minimum water in the distillation and hence, steam channeling phenomenon was overcome. Furthermore, we obtained optimum steam flow rate and time for extraction of the oil. Using a multistage column with suitable steam redistributors results in reduction of pressure drop, and steam channeling in the column, hence, increacing the yield of extraction. This research revealed different behaviors of the main components of rosemary oil; α-pinene, 1,8-cineole and camphor in treating with amount of steam flow rate.