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Supercritical co2 extraction distillation of millet bran oil

Millet bran oil

With the development of social economy, people are paying more and more attention to health issues.

Supercritical co2 extraction distillation of millet bran oil

In recent years, people have gradually transitioned from eating high-fat animal fats to eating nutritious and healthy vegetable oils.

Millet is a by-product of the processing of millet after being shelled into refined millet. It is rich in various nutrients.

The gluten oil produced by it is a healthy oil. The proportion of fatty acids contained is more consistent with the common cooking oil. Nutritional requirements, in addition to food, can also be widely used in medicine, health care products, cosmetics and other industries.

Process conditions for extracting gluten by supercritical co2

The extraction conditions of gluten oil were used as indicators to study the process conditions of supercritical co2 extraction of gluten. The supercritical co2 fluid extraction-rectification study summarizes the effects of extraction pressure, extraction temperature, extraction time, co2 flow rate on oil yield, rectification pressure, and rectification temperature on rectification.

The results showed that the optimum extraction conditions were extraction pressure 30 MPa, extraction temperature 45°C, extraction time 2h, co2 flow 50kg/h, grain size 40 mesh, moisture content 7%. The oil yield under this condition was 19.69%.

Experimental results

The most suitable conditions for supercritical co2 rectification of gluten oil are extraction pressure 30 MPa, extraction temperature 45 ° C, extraction time 2 h, co2 flow 50 kg / h, rectification column pressure 10 MPa, rectification temperature rectification I: 40 ° C, fine Distillation II: 45 ° C, rectification III: 50 ° C, rectification IV: 55 ° C.

By measurement, the supercritical extraction method extracts gluten oil containing high unsaturated fatty acids, especially containing up to 67.8% of linoleic acid.

The physical and chemical indicators of extracting gluten oil by comparison of supercritical extraction method are better than the commercially available gluten oil.

Therefore, fluid extraction-rectification by supercritical co2 is a better method for extracting gluten.


China has abundant glutinous resources, with an annual output of more than 2 million tons of millet and more than 100,000 tons of glutinous rice.

The development of it can not only effectively use agricultural waste resources, reduce waste, but also help farmers get rich and improve people’s living standards. It is of great significance. At present, the price of gluten is about 100,000-600,000 yuan/ton. China’s vigorous development of the gluten oil industry has broad prospects.


The use of supercritical co2 fluid to extract millet bran oil from millet bran has many advantages, such as high solubility in extraction, faster mass transfer rate, better flow and balance, and good adjustability.

And easy to control, and maintain the biological activity of nutrients in the gluten oil. And avoiding environmental pollution, the process is non-toxic and non-polluting, and achieves clean production.

The millet bran oil extracted by supercritical extraction contains high unsaturated fatty acids, especially containing up to 67.8% of linoleic acid.
Extraction pressure: 30 MPa

Extraction temperature: 45°C

Extraction time: 2 h

Co2 flow: 50 kg/h

Rectification column pressure: 10 MPa

Rectification temperature rectification I: 40°C

Fine Distillation II: 45°C

Rectification III: 50°C

Rectification IV: 55°C