A kind of extraction technology of Citronella Fragrance Oil, comprises the following steps:
(1) Lemongrass is ground at -50°C at a low temperature to 20 mesh to obtain lemongrass powder;
(2) Put the citronella powder in the extraction kettle, add 4 times the weight of the extraction agent soybean oil, soak for 30 minutes, turn on the vacuum pump, wait until the pressure in the extraction kettle reaches -0.1Mpa, and use the pressure difference between the extraction kettle and the solvent tank. The solvent butane in the solvent tank is injected into the extraction kettle. Under the conditions of extraction temperature of 55°C and extraction pressure of 1.0MPa, after extraction for 7 hours, the extract enters the separation tank;
(3) The extract is separated in the separation tank at a temperature of 55°C and a pressure of -0.1MPa for 5 minutes. After the solvent is separated, it returns to the solvent tank, and the citronella mixed oil is collected from the outlet valve of the separation tank, which is citronella. Turmeric oil (a blend of citronella essential oil and soybean oil).
After the slag in the extraction kettle is desolvated under reduced pressure, the citronella slag is collected.
The water content of citronella in step (1) is 10%, and the ratio of citronella powder to butane in the extraction process of step (2) is 1Kg:4L.
The extraction rate of citronella essential oil is (citronella oil-soybean oil)/citronella grass*100%, and the extraction rate of citronella essential oil in this example is 4.32%.
A method for extracting Citronella Fragrance Oil, comprising the steps of:
1) Cut the dried lemongrass stems and leaves (naturally sun-dried or dried) into short pieces;
2) The cut citronella stems and leaves are pressed into pieces, put into filter bags, and fed into the subcritical equipment extraction kettle;
3) Pour into subcritical fluid (may contain entrainer);
4) Control the pressure and temperature for static extraction and decompression separation to obtain citronella extract;
5) Repeat step 3) and step 4) once or several times, combine the extracts, drain, let stand for stratification, and the upper oil layer is the finished product of citronella oil.
Further, the stems and leaves of citronella are citronella species such as citral type and Java type.
Further, the cut short pieces are 1-3 cm long.
Further, the tableting process is to press into a round cake (with a diameter smaller than the inner diameter of the extraction tank), and put in lemongrass stems and leaves and a fluid with a solid-to-liquid ratio of 1:1.5-3 (g/l).
Further, the subcritical fluid is one or more of propane, butane, dimethyl ether (DEM), and isobutane.
Further, the entrainer can be a conventional solvent such as alcohol.
Further, the pressure and temperature of the countercurrent extraction are 0.3-1.2MPa, 30-60°C, and a single extraction time is 20-50min.