Optimization of essential oil extraction from orange peels using steam explosion

In this work, a new extraction process using steam explosion at high temperature and pressure was developed, to drastically shorten the extraction time and improved extraction of the essential oil from citrus peels. In steam explosion process, the material is subjected to the high-pressure saturated steam following by substantially dropping the pressure through an angle valve to a vacuum tank. The optimum essential oil yield by the steam explosion was obtained at the 170 °C, 8 bar in 240 seconds duration time. The essential oil extraction of a certain amount of citrus peels by hydro-distillation took nearly eight times longer than explosion extraction process. The obtained citrus oil from hydro-distillation processes had 10 to 13 major components more than‏ the steam explosion, as shown by gas chromatography (GC-MS). The maximum product yield of Limonene, a major favorable component, were 77% and 100% in hydro-distillation and steam explosion processes, respectively.