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CN-122012175-A - Supercritical CO2Green low-temperature refining process for sunflower seed oil

CN122012175ACN 122012175 ACN122012175 ACN 122012175ACN-122012175-A

Abstract

The invention relates to the technical field of grease processing and refining, and discloses a supercritical CO 2 green low-temperature refining process of sunflower seed oil, which comprises the steps of carrying out continuous tubular mild degumming on crude sunflower seed oil to obtain degummed oil; in a continuous countercurrent extraction tower, supercritical carbon dioxide is combined with variable frequency pulse injection entrainer to perform deacidification extraction, the obtained homogeneous fluid is introduced into a high-pressure fixed bed at the same temperature and at the same pressure, spherical mesoporous composite adsorbent is utilized to perform penetration decolorization, decolorized fluid is subjected to stepped decompression separation to obtain refined base oil, the refined base oil is continuously deodorized to obtain finished refined oil, short-range molecular distillation is performed on deodorized distillate to separate free fatty acid and recover vitamin E and plant sterol, and transient stepped decompression is utilized to perform in-situ desorption regeneration on saturated adsorbent. The invention avoids the grease saponification loss and the waste clay pollution caused by the traditional chemical alkali refining, effectively intercepts and enriches the thermosensitive micronutrient accompaniment during the whole process of low-temperature operation.

Inventors

  • GUO KUNPENG

Assignees

  • 山东圣道尔农业科技发展有限公司

Dates

Publication Date
20260512
Application Date
20260408

Claims (10)

  1. 1. The green low-temperature refining process of the supercritical CO 2 sunflower seed oil is characterized by comprising the following steps of: continuous tubular mild degumming is carried out on the sunflower seed crude oil, and the water-converted oil residue is centrifugally separated to obtain degummed oil; Inputting the degummed oil into a continuous countercurrent extraction tower, introducing supercritical carbon dioxide fluid, injecting entrainer according to a periodic variable frequency pulse mode, and performing deacidification extraction to obtain homogeneous fluid containing neutral grease and dissolved carbon dioxide; directly introducing the homogeneous fluid containing neutral grease and dissolved carbon dioxide into a high-pressure fixed bed filled with spherical mesoporous composite adsorbent under the same temperature and pressure state, continuously penetrating the bed layer for decoloring, and obtaining decolored fluid; Carrying out step decompression analysis on the decolorized fluid, separating out gaseous carbon dioxide and liquid-phase refined base oil, and recycling the gaseous carbon dioxide through a condenser; Continuously deodorizing the liquid-phase refined base oil, collecting deodorized distillate obtained by condensing at the top of the tower, and collecting finished refined oil from the bottom of the tower; carrying out short-range molecular distillation treatment on the deodorized distillate, separating free fatty acids and recovering a product enriched with vitamin E and phytosterol; And introducing supercritical carbon dioxide fluid into the spherical mesoporous composite adsorbent reaching adsorption saturation for static soaking, and performing step pressure relief to perform in-situ desorption regeneration.
  2. 2. The green low-temperature refining process of supercritical CO 2 sunflower seed oil according to claim 1, wherein the specific operation of continuous tubular mild degumming of crude sunflower seed oil is as follows: Heating sunflower seed crude oil to 45-55 ℃ through a heat exchange system, injecting a phosphoric acid aqueous solution with the mass concentration of 85% along a pipeline, controlling the addition amount of the phosphoric acid aqueous solution to be 0.1-0.3% of the mass of the crude oil, standing fluid in the pipeline for reaction for 15-30 minutes, then injecting pure water with the mass of 1-3% of the crude oil, entering a stirring kettle for hydration reaction for 20-40 minutes at the rotating speed of 40-60rpm, and finally continuously centrifuging to separate out water-converted oil residues through a disc centrifuge.
  3. 3. The green low-temperature refining process of supercritical CO 2 sunflower seed oil according to claim 1, wherein when deacidification extraction is carried out, the system pressure of the continuous countercurrent extraction tower is controlled to be 15.0-28.0MPa, the temperature is controlled to be 35-55 ℃, and the total mass ratio of gas to liquid is maintained to be (5-15): 1; The frequency conversion pulse injection mode of the entrainer is that 3-5 minutes is set as a complete injection period, the injection flow of the entrainer accounts for 4.0% of the total mass of the fluid in the first 30-35% of the period, and the injection flow of the entrainer accounts for 0-1.0% of the total mass of the fluid in the rest period.
  4. 4. The supercritical CO 2 sunflower seed oil green low-temperature refining process according to claim 3, wherein the entrainer is formed by mixing the following components in percentage by weight: 88-95% of main solvent; 2-2.5% of organic acid; 3-10% of an emulsifying agent; The main solvent is absolute ethyl alcohol or isopropanol, the organic acid is citric acid or ascorbic acid, and the emulsifier is glyceryl monostearate, polysorbate-80 or diglycerol monostearate.
  5. 5. The green low-temperature refining process of supercritical CO 2 sunflower seed oil according to claim 1, wherein the empty tower residence time of the homogeneous fluid containing neutral grease and dissolved carbon dioxide in the high-pressure fixed bed filled with spherical mesoporous composite adsorbent is controlled to be 20-40 minutes when decolorization is carried out.
  6. 6. The green low-temperature refining process of supercritical CO 2 sunflower seed oil according to claim 5, wherein the preparation method of the spherical mesoporous composite adsorbent comprises the following steps: Chitosan with deacetylation degree of 85-95% is dissolved in glacial acetic acid aqueous solution with volume concentration of 1.0-2.0% to prepare chitosan glue solution with mass concentration of 2-4%; Mixing tetraethyl orthosilicate with absolute ethyl alcohol according to the volume ratio of 1 (1-3), adding deionized water with the volume of 20-30% of the tetraethyl orthosilicate, dripping hydrochloric acid solution with the concentration of 0.1mol/L to adjust the pH value of the system to 2.0-3.0, and stirring for 1-2 hours at the rotating speed of 300-500rpm at the temperature of 40-50 ℃ to prepare silica sol; Dripping the chitosan glue solution into the silica sol at a constant speed of 5-10mL/min, adding sodium alginate with the dry weight of 1-2% of chitosan, adding genipin water solution with the pure substance addition amount of 1-5% of the dry weight of chitosan and the mass concentration of 0.5-1.5% as a cross-linking agent, and stirring and reacting for 2-3 hours at the temperature of 50-60 ℃ at the rotating speed of 150-250rpm to form semi-gel; Dropping the semi-gel into 0-5 ℃ absolute ethyl alcohol coagulation bath containing 2% of anhydrous calcium chloride through a drip spray nozzle with the aperture of 1-3mm, and solidifying to obtain spherical gel particles; aging the spherical gel particles for 12-24 hours at room temperature, repeatedly washing to neutrality, pre-freezing ice at-60 ℃ to-40 ℃, and then vacuum freeze-drying for 24-48 hours at the absolute pressure of a system of 10-30Pa to obtain the spherical mesoporous composite adsorbent.
  7. 7. The supercritical CO 2 sunflower seed oil green low-temperature refining process according to claim 1, wherein the specific operation of performing step decompression analysis on the decolorized fluid is as follows: The decolorized fluid enters a separation system, the pressure of a primary separation kettle is controlled at 8-12MPa, the temperature is controlled at 40-50 ℃, the pressure of a secondary separation kettle is controlled at 4-6MPa, and the temperature is controlled at 30-40 ℃.
  8. 8. The supercritical CO 2 sunflower seed oil green low-temperature refining process according to claim 1, wherein when continuous deodorization is carried out, the absolute pressure in a deodorization tower is maintained at 150-350Pa, the temperature of heat conduction oil in a heating section is controlled to be 175-195 ℃, a stripping section of the deodorization tower is filled with corrugated structured packing with the specific surface area of 250-350 square meters per cubic meter, direct steam with the oil weight of 0.5-1.5% is introduced from the bottom of the tower, and the total residence time of the oil in the tower is 60-100 minutes.
  9. 9. The supercritical CO 2 sunflower seed oil green low-temperature refining process according to claim 1, wherein the specific operation of short-path molecular distillation treatment of the deodorized distillate is: pre-deaerating the deodorized distillate for 10-20 minutes under the vacuum degree of 1-2kPa and the temperature of 60-80 ℃; The materials enter a first-stage short-path molecular distillation, the temperature of an evaporation surface is 120-140 ℃, the vacuum degree of a system is 5-20Pa, the rotating speed of a film forming scraper is 200-350rpm, and light component free fatty acid is separated; the residual heavy component enters a secondary short-path molecular distillation, the temperature of an evaporation surface is 180-210 ℃, the vacuum degree of a system is 0.1-1.0Pa, the rotating speed of a film forming scraper is 250-400rpm, and a light phase on a secondary condensation surface is collected to obtain a product enriched with vitamin E and plant sterol.
  10. 10. The green low-temperature refining process of supercritical CO 2 sunflower seed oil according to claim 1, wherein the specific operation of in-situ desorption regeneration is: Introducing a pure supercritical carbon dioxide fluid with the temperature of 50-60 ℃ and the pressure of 20-25MPa, and statically soaking the high-pressure fixed bed for 15-20 minutes; Opening a fixed bed jacket heat exchange system, and introducing waste heat steam at 110-130 ℃; Implementing the first step pressure relief, regulating a pressure relief valve to reduce the internal fluid pressure of the bed layer to 8-10MPa within 1-2 minutes, and keeping the pressure for 1 minute; Step decompression is carried out for the second time, and the pressure is further reduced to 1.0-2.0MPa within 2-3 minutes; recharging to 20-25MPa, and repeating the two-step decompression operation for 2-3 times; Finally, waste heat steam at 110-130 ℃ is directly introduced into the fixed bed, and the waste heat steam is purged for 30-60 minutes under normal pressure.

Description

Supercritical CO 2 sunflower seed oil green low-temperature refining process Technical Field The invention relates to the technical field of grease processing and refining, in particular to a supercritical CO 2 sunflower seed oil green low-temperature refining process. Background The sunflower seed oil contains a large amount of unsaturated fatty acid and trace nutrient accompanying matters such as vitamin E, plant sterol and the like, and the industrial refining process of the sunflower seed oil mainly depends on traditional process links such as chemical alkali refining, clay decolorization, high-temperature deodorization and the like at present, and the conventional process has obvious technical defects in the aspects of material yield, environmental protection and product nutrition retention. In the conventional deacidification link, chemical alkali liquor is generally added to neutralize free fatty acid in crude oil, saponification reaction of neutral grease is extremely easy to be initiated in the operation, absolute loss of the neutral oil is caused, the final yield of finished oil is reduced, and a large amount of high-concentration pollution soapstock is generated in the neutralization reaction, so that the waste water and solid waste treatment pressure of front-end working procedures of a factory is greatly increased. In the subsequent decoloring step, the prior art mostly adopts direct addition of high-temperature activated clay for pigment adsorption, pore channel structure is solidified after clay adsorption saturation, effective desorption and regeneration are difficult, a large amount of waste clay can only be directly treated as industrial solid waste, serious environmental protection burden is brought, and partial grease can be adsorbed and entrained in the waste clay, so that resource loss in the whole processing process is further aggravated. In the deodorization link at the tail end, the conventional process relies on high-temperature steam to carry out low-pressure steam stripping, the continuous high-temperature environment is easy to induce thermal oxidation degradation of lipid, so that trans-fatty acid is generated, the naturally-enriched thermosensitive antioxidant substances in sunflower seed oil can be degraded and consumed in a large amount under the long-time action of high temperature, and the existing equipment is difficult to separate volatile odor molecules and realize nondestructive separation and recycling of high-added-value nutritional components in distillate. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a supercritical CO 2 sunflower seed oil green low-temperature refining process, which solves the problems of the traditional refining process that the saponification loss of neutral oil and a large amount of soapstock pollution are caused by chemical alkali refining, the solid waste burden is caused by the incapability of regenerating waste carclazyte, and the thermal oxidation degradation of lipid and the consumption of heat-sensitive nutrient substances are caused by high-temperature operation. In order to achieve the above purpose, the invention is realized by the following technical scheme: a supercritical CO 2 sunflower seed oil green low-temperature refining process comprises the following steps: continuous tubular mild degumming is carried out on the sunflower seed crude oil, and the water-converted oil residue is centrifugally separated to obtain degummed oil; Inputting the degummed oil into a continuous countercurrent extraction tower, introducing supercritical carbon dioxide fluid, injecting entrainer according to a periodic variable frequency pulse mode, and performing deacidification extraction to obtain homogeneous fluid containing neutral grease and dissolved carbon dioxide; directly introducing the homogeneous fluid containing neutral grease and dissolved carbon dioxide into a high-pressure fixed bed filled with spherical mesoporous composite adsorbent under the same temperature and pressure state, continuously penetrating the bed layer for decoloring, and obtaining decolored fluid; Carrying out step decompression analysis on the decolorized fluid, separating out gaseous carbon dioxide and liquid-phase refined base oil, and recycling the gaseous carbon dioxide after compression; Continuously deodorizing the liquid-phase refined base oil, collecting deodorized distillate obtained by condensing at the top of the tower, and collecting finished refined oil from the bottom of the tower; carrying out short-range molecular distillation treatment on the deodorized distillate, separating free fatty acids and recovering a product enriched with vitamin E and phytosterol; and introducing supercritical carbon dioxide fluid into the spherical mesoporous composite adsorbent reaching adsorption saturation for static soaking, and then implementing transient step pressure relief to perform in-situ desorption regeneration. By adopt