Effect of extraction time on the oil yield of supercritical CO2 extraction
Experiments show that the longer the extraction time, the higher the oil yield.
How to choose the SCF extraction time
In the initial stage of extraction, the oil yield increases significantly; however, with the extension of the extraction time, the oil yield increases slowly, there is an end of economic time, and the selectivity of extraction also decreases.
In order to reduce costs and improve equipment efficiency, the extraction time is generally 1~3 h in consideration of comprehensive considerations. Compared with other extraction techniques, SC-CO2 extraction requires a shorter time.
Under the condition of ensuring the oil yield, 40 min~3 h is sufficient for most samples.
Extraction time affects the fatty acid composition of the oil
In addition, the extraction time affects the fatty acid composition of the oil. When extracting tomato seed oil at 40 ℃ and 24.5 MPa, low-carbon chain fatty acids (C10:0, C12:0, C13:0, C14:0, C14:1) were extracted in the first 30 minutes.
The results of the study on SC-CO2 extraction of palm oil also show that shorter chain fatty acids are higher in the beginning of the extraction.
The experiment of extracting corn germ oil with SC-CO2 fluid shows that when the extraction temperature and extraction pressure are constant, with the extension of the extraction time, the content of the relatively volatile component palmitic acid in the oil gradually decreases, and the relatively low volatile component oleic acid The content gradually increased.