Cottonseed oil purification method and cottonseed oil

Abstract

The invention relates to a cottonseed oil purification method and cottonseed oil, and the method comprises the following steps: sequentially performing oil expression, separation and filtration on pretreated cottonseeds to obtain crude cottonseed oil; heating the wool cotton oil to a preset temperature, and carrying out primary smelting treatment to obtain third-grade cotton oil; degumming the third-stage cottonseed oil, adding an alkaline solution for deacidification, adding a specific decolorizing agent for decolorizing, filtering, and deodorizing to obtain second-stage cottonseed oil; winterizing and degreasing the second-grade cottonseed oil to obtain purified first-grade cottonseed oil.

Description

Technical Field

[0001] The invention relates to the technical field of cottonseed oil purification, in particular to a cottonseed oil purification method and cottonseed oil. Background Art

[0002] Cottonseed oil is a high-grade edible oil, rich in essential fatty acids, of which about 80% are oleic acid and linoleic acid, unsaturated fatty acids and vitamins A, D, E, phosphorus, calcium, iron, potassium, sodium are also relatively rich, which can reduce the cholesterol and triglyceride content in serum, prevent atherosclerosis, and is suitable for malnourished people with hyperlipidemia. The existing cottonseed oil refining process produces a large amount of unpleasant, toxic and harmful substances, and there are problems such as high energy consumption, long processing cycle and high impurity content in the production process, which affect the quality of cottonseed oil; with the development of my country's edible oil market, there will be a large development space for oil used by special groups of healthy people, but my country's special oil started late, the production method is relatively traditional, and there are few products on the market, and it is urgent to develop special oils.

[0003] During the processing of cottonseed oil, a large amount of de-oiled cottonseed meal is produced. For every ton of cottonseed oil produced, more than four tons of defatted cottonseed meal are produced. The defatted cottonseed meal also contains 40% to 50% of cottonseed oil with high usable value. Since defatted cottonseed meal is a by-product of the cottonseed oil production process, most of it is processed into fertilizers, feed, etc., resulting in a waste of cottonseed resources and environmental pollution. If cottonseed meal can be effectively recycled and utilized, the utilization value of cottonseed will be greatly improved.

[0004] The method for extracting cottonseed oil in the prior art is a fractionation method, wherein the raw cottonseed oil is subjected to hot filtration to remove cottonseed protein insolubles and cottonseed cakes; clean water and quicklime are added to the filtrate in a degumming tank, and the pH value is adjusted to alkaline to remove soluble protein colloids, cottonphenol, etc. in the raw cottonseed oil; in order to prevent protein denaturation, the filtrate needs to be heated to 65-70°C, and the protein is condensed and suspended at 90°C, and then filtered with a 40-mesh filter cloth, thereby removing the protein to obtain a crude cottonseed oil; then, a certain amount of hot water is added to the crude cottonseed oil for hot water extraction to obtain a water phase and an oil phase, wherein the water phase is water-containing cottonseed oil, which is circulated back to the degumming tank after being heated by a water vapor circulation and heated to be reused; and the oil phase is degummed cottonseed oil, which is vacuum distilled to obtain the degummed cottonseed oil. Although this traditional method can remove some impurities in cottonseed oil to a certain extent, the degumming effect is not obvious due to the short degumming time and insufficient temperature. The degumming effect is not good, the amount of wastewater is large, the water-containing cottonseed oil is repeatedly reused, and the process cycle is long, which makes the production efficiency relatively low.

[0005] The existing cottonseed oil refining process produces a large amount of unpleasant, toxic and harmful substances. The production process has high energy consumption, long processing cycle and high impurity content, which affects the quality of cottonseed oil. Defatted cottonseed meal contains high-value cottonseed oil, but most of it is processed into fertilizer, feed, etc., causing resource waste and environmental pollution. The fractionation method for refining cottonseed oil has a short degumming time, the temperature is not high enough, the degumming effect is not obvious, the degumming effect is not good, the amount of wastewater is large, the process cycle is long, and the production efficiency is low. Summary of the invention

[0006] The main purpose of the present invention is to overcome the defects of the existing cottonseed oil purification method and cottonseed oil, and to provide a new cottonseed oil purification method and cottonseed oil, which can at least solve the problem of generating a large amount of unpleasant, toxic and harmful substances in the existing cottonseed oil refining process. The production process has high energy consumption, long processing cycle and high impurity content, which affect the quality of cottonseed oil; the defatted cottonseed meal contains high-value cottonseed oil, but most of it is processed into fertilizer, feed, etc., causing resource waste and environmental pollution; the fractionation method for refining cottonseed oil has a short degumming time, the temperature is not high enough, the degumming effect is not obvious, the degumming effect is not good, the amount of wastewater is large, the process cycle is long, and the production efficiency is low.

[0007] Compared with the prior art, the present invention has obvious advantages and beneficial effects. From the above technical scheme, it can be seen that in order to achieve the above-mentioned invention purpose, the main technical contents of the present invention are as follows:

[0008] The present invention provides a cottonseed oil purification method, comprising: a cottonseed oil refining step: sequentially pressing, separating and filtering pretreated cottonseeds to obtain cottonseed oil;

[0009] The secondary cottonseed oil processing steps include: heating the raw cotton oil to a preset temperature for primary refining to obtain the third-grade cottonseed oil, degumming the third-grade cottonseed oil, heating the degummed third-grade cottonseed oil to 70° C. to 90° C., adding an alkaline solution, stirring for 30 minutes to 35 minutes, separating the neutral oil by a centrifuge, drying the neutral oil and heating it to 110° C. to 120° C., adding a decolorizing agent and stirring, filtering and separating, heating it to 180° C. to 210° C., and distilling it with saturated steam for 2 hours under a vacuum state to obtain the secondary cottonseed oil;

[0010] First-grade cottonseed oil processing:

[0011] Evaporation step: heating the secondary cottonseed oil to 180° C. to 200° C., keeping the temperature constant for 10 to 20 minutes, and continuing to heat the oil to evaporate the glycerin in the secondary cottonseed oil to obtain the secondary cottonseed oil with evaporated glycerin;

[0012] Alkali translocation step: adding a first content of food-grade sodium hydroxide to the secondary cottonseed oil from which glycerol has been evaporated, stirring and reacting for 3 to 5 minutes; adding a second content of food-grade sodium hydroxide, stirring and reacting for 3 to 5 minutes to obtain an alkali translocation liquid;

[0013] Acid oil, neutralization reaction step: react the alkali translocation liquid with phosphoric acid, then add water and stir until there is no residue; wherein the mass of the phosphoric acid is 3% to 5% of the mass of the alkali translocation liquid;

[0014] Dehydration and fine filtration steps: the liquid after acid oil and neutralization reaction is heated to 180°C to 200°C, kept warm for 2 to 3 hours, cooled and filtered, and then first-level fine filtration and second-level fine filtration are carried out in sequence to obtain purified second-level cottonseed oil.

[0015] In an optional embodiment, the degumming treatment time in the secondary cottonseed oil processing step is 15 minutes to 25 minutes.

[0016] In an optional embodiment, the preset temperature of the degumming treatment is 80°C to 90°C.

[0017] In an optional embodiment, the alkaline solution includes calcium carbonate or magnesium carbonate solution;

[0018] The molar ratio of the alkaline solution to the cottonseed oil is 1:1 to 1.05.

[0019] In an optional embodiment, in the base translocation step, the first content is less than the second content;

[0020] The molar ratio of the primary lime to the first content of calcium oxide is 30:1-3;

[0021] The molar ratio of the secondary lime to the second content of calcium oxide is 15:1-3.

[0022] In an optional embodiment, the molar ratio of the first content to the second content is 1:3.5-5.

[0023] In an optional embodiment, the amount of primary lime and calcium oxide added accounts for 50% to 60% of the total amount of lime to be added; the amount of secondary lime and calcium oxide added accounts for 40% to 70% of the total amount of lime to be added.

[0024] In an optional embodiment, the nutrients forming cottonseed oil include 13% to 15% protein, 6% to 8% water, and the rest is oil;

[0025] In the secondary cottonseed oil processing step, the degummed raw cotton oil is added to an alkaline solution and heated to 180° C. to 200° C., the protein in the cottonseed oil reacts with the alkaline solution, the protein condenses to form a solid protein which is separated from the cottonseed oil, and the secondary cottonseed oil is obtained after filtering.

[0026] In an optional embodiment, the degumming temperature in the secondary cottonseed oil processing step, the evaporation temperature in the evaporation step, the alkali translocation reaction temperature in the alkali translocation step, the acid oil, the acid oil reaction temperature in the neutralization reaction step and the dehydration temperature in the dehydration fine filtration step are all the same.

[0027] On the other hand, a purified secondary cottonseed oil is provided, wherein the purified secondary cottonseed oil is purified by any of the methods described above.

[0028] By means of the above technical solution, the present invention (name) has at least the following advantages:

[0029] The cottonseed oil purification method and cottonseed oil provided in the embodiment of the present invention are analyzed according to the nutritional components of cottonseed oil. At a high temperature of 180°C to 200°C, when the protein colloid encounters a high temperature alkali, the colloid condenses, the condensed protein is separated from the cottonseed oil, and the protein becomes solid, so that the protein is separated from the oil, and the formation of protein colloid is avoided. By removing glycerol at a high temperature of 180°C to 200°C, the water content of the crude oil in the cottonseed oil is reduced to 3-5%, so that the subsequent alkali translocation step is more perfect. The alkali translocation step of the present invention reduces the time of alkali translocation, reduces the consumption of alkali, improves the utilization rate of alkali, reduces the concentration of alkali in waste alkali water, reduces the pollution of waste alkali water discharge, and improves the process flow of the alkali translocation reaction. The hydrolysis phenomenon in the conventional alkaline deoiling process is changed by the acid oil and neutralization reaction steps. Due to the reduced consumption of alkali, the side reactions produced are also reduced, so that the hydrolysis phenomenon is better controlled, and the crude oil content produced is increased to 80% to 85%; the amount of acid is reduced to 1 / 3 of the original process, and the acidity in the wastewater is controlled to 0.1%, which improves the quality of the finished oil produced and reduces the discharge of waste acid water. The dehydration temperature is increased to 180°C to 200°C through the dehydration fine filtration step, and the dehydration time is increased to 2 hours. After dehydration, the moisture is reduced to 0.4%, and the cottonseed oil produced reaches 95% to 98%, which greatly improves the quality of the cottonseed oil. In the dehydration reaction process, due to the high reaction temperature and long reaction time, the amount of cottonseed oil acid produced is reduced to 0.2%, which reduces the amount of activated carbon used in the fine filtration step and reduces the water consumption in the fine filtration process. The method provided in the embodiment of the present invention produces less wastewater and waste alkali liquid, and the obtained cottonseed oil is of high quality, which can reach a product containing more than 80% cottonseed oil, so that the comprehensive utilization of cottonseed oil produces significant economic value.

[0030] In summary, the special cottonseed oil purification method and cottonseed oil of the present invention can solve the problem of producing a large amount of unpleasant, toxic and harmful substances in the existing cottonseed oil refining process. The production process has high energy consumption, long processing cycle and high impurity content, which affects the quality of cottonseed oil; the defatted cottonseed meal contains high-value cottonseed oil, but most of it is processed into fertilizer, feed, etc., causing resource waste and environmental pollution; the fractionation method for refining cottonseed oil has short degumming time, low temperature, unobvious degumming effect, poor degumming effect, large amount of wastewater, long process cycle and low production efficiency. It has the above-mentioned advantages and practical values, and no similar design has been publicly published or used in similar cottonseed oil purification methods and cottonseed oil, so it is indeed innovative. It has great improvements in both the cottonseed oil purification method and cottonseed oil or in function, and has great progress in technology, and has produced good and practical effects. It has improved multiple functions compared with the existing cottonseed oil purification method and cottonseed oil, so it is more suitable for practical use and has wide industrial utilization value. It is truly a novel, progressive and practical new design.

[0031] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention provides a schematic flow chart of a cottonseed oil purification method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the cottonseed oil purification method and the specific implementation method of cottonseed oil proposed in the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0034] See also Figure 1 The cottonseed oil purification method of the preferred embodiment of the present invention mainly comprises the following steps: Raw cottonseed oil refining step S101: pressing, separating and filtering the pretreated cottonseed in sequence to obtain raw cottonseed oil.

[0035] Secondary cottonseed oil processing step S102: heating the raw cotton oil to a preset temperature for primary refining to obtain third-grade cottonseed oil, degumming the third-grade cottonseed oil, heating the degummed third-grade cottonseed oil to 70° C. to 90° C., adding an alkaline solution, stirring for 30 minutes to 35 minutes, separating neutral oil with a centrifuge, drying the neutral oil and heating it to 110° C. to 120° C., adding a decolorizing agent and stirring, filtering and separating, heating it to 180° C. to 210° C., and distilling it with saturated steam for 2 hours under a vacuum state to obtain secondary cottonseed oil;

[0036] The primary cottonseed oil processing includes an evaporation step S103, an alkali translocation step S104, and an acid oil and neutralization reaction step S105.

[0037] Evaporation step S103: heating the secondary cottonseed oil to 180° C. to 200° C., maintaining the temperature for 10 to 20 minutes, and continuing to increase the temperature to evaporate the glycerin in the secondary cottonseed oil to obtain the secondary cottonseed oil with evaporated glycerin.

[0038] Alkali translocation step S104: add a first content of food-grade sodium hydroxide to the secondary cottonseed oil, stir and react for 3 to 5 minutes; add a second content of food-grade sodium hydroxide, stir and react for 3 to 5 minutes to obtain an alkali translocation liquid.

[0039] Acid oil, neutralization reaction step S105: react the alkali translocation liquid with phosphoric acid, then add water and stir until there is no residue; wherein the mass of the phosphoric acid is 3% to 5% of the mass of the alkali translocation liquid.

[0040] Dehydration fine filtration step S106: The liquid after acid oil and neutralization reaction is heated to 180°C to 200°C, kept warm for 2 to 3 hours, cooled and filtered, and then first-level fine filtration and second-level fine filtration are performed in sequence to obtain purified second-level cottonseed oil.

[0041] The method provided by the embodiment of the present invention generates less waste water and waste alkali liquor, and the obtained cottonseed oil is of high quality, and can reach a product containing more than 80% cottonseed oil, so that the comprehensive utilization of cottonseed oil produces significant economic value.

[0042] The cottonseed oil purification method provided by the present invention will be explained and described in detail below through optional embodiments.

[0043] In the raw cotton oil refining step S101, the pretreated cotton seeds are sequentially subjected to oil pressing, separation and filtration to obtain raw cotton oil. The pretreated cotton seeds are put into a hot press for oil pressing, and enter a raw oil tank to separate the cotton core, and then the raw oil enters a vacuum filter for filtration, and the oil is discharged into an oil storage tank.

[0044] In the secondary cottonseed oil processing step S102, the raw cottonseed oil is heated to a preset temperature for degumming, and the degummed raw cottonseed oil is added to an alkaline solution, heated to 180°C to 200°C, and kept at a constant temperature for 2 to 3 hours, and filtered to obtain the secondary cottonseed oil. For example, it can be heated to 180°C, 183°C, 185°C, 190°C, 195°C or 200°C, etc., and kept at a constant temperature for 2 hours or 3 hours.

[0045] In an optional embodiment, the degumming treatment time in the secondary cottonseed oil processing step is 15 minutes to 25 minutes. Exemplarily, it can be 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes, 20 minutes, 21 minutes, 22 minutes, 23 minutes, 24 minutes or 25 minutes, etc.

[0046] In an optional embodiment, the preset temperature of the degumming process is 80° C. to 90° C. For example, it can be 80° C., 83° C., 85° C. or 90° C.

[0047] The degumming reaction temperature of the conventional alkaline degumming method is 80℃~90℃. Cottonseed protein reacts with alkali to form protein colloid, which makes the protein become pasty. Under the condition of heating, the protein colloid is condensed into a mass, which causes the cottonseed protein to hydrolyze and produce oil, and the recovery of protein is reduced, so that the cottonseed oil content is only between 50% and 65%. According to the nutritional component analysis of cottonseed oil, the cottonseed protein only accounts for about 12%~15% of the cottonseed mass percentage, while the water content is 6%~8%, and the oil content is about 36%. The embodiment of the present invention adopts a high-temperature alkali degumming method, and the degumming temperature is increased to 180℃~200℃. When the protein encounters high-temperature alkali, the protein condenses into protein colloid, and the condensed protein colloid is separated from the cottonseed oil. The protein colloid becomes solid and is separated from the oil. The embodiment of the present invention increases the degumming temperature, so that the water in the cottonseed oil is completely evaporated, avoiding the formation of protein colloid. In the degumming process, the separation of protein meets the process requirements of separating cottonseed oil and protein.

[0048] In the evaporation step S103, the secondary cottonseed oil is heated to 180°C to 200°C, illustratively, it can be heated to 180°C, 183°C, 185°C, 190°C, 195°C or 200°C, etc. The temperature is kept constant for 2 hours or 3 hours, and the temperature is continuously raised to evaporate the glycerin in the secondary cottonseed oil to obtain the secondary cottonseed oil.

[0049] In the embodiment of the present invention, the third-grade cottonseed oil from which glycerol is evaporated is piped to a glycerol evaporation tank, steam heated to 180° C., and kept at a constant temperature for 10 minutes. Then, steam heats the glycerol, and the evaporated water vapor is passed to a steam bag, and the water is collected as recycled water and passed to a crude oil filter. After the glycerol is completely evaporated, the glycerol is passed to a glycerol recovery tank for metering, and then the glycerol is passed through a glycerol metering pump to a glycerol finished product tank, and the glycerol can be packaged for sale. In the glycerol evaporation tank, the cottonseed oil liquid is dripped into an alkali transposition pot for alkali transposition treatment.

[0050] In the alkali translocation step S104, a first content of food-grade sodium hydroxide is added to the secondary cottonseed oil, and the mixture is stirred for reaction for 3 minutes, 4 minutes or 5 minutes; a second content of food-grade sodium hydroxide is added, and the mixture is stirred for reaction for 3 minutes, 4 minutes or 5 minutes to obtain an alkali translocation liquid.

[0051] In an optional embodiment, the alkaline solution includes a calcium carbonate or magnesium carbonate solution; and the molar ratio of the alkaline solution to the cottonseed oil is 1:1 to 1.05. For example, it can be 1:1 or 1:1.05.

[0052] In an optional embodiment, in the base transfer step, the first content is less than the second content.

[0053] In an optional embodiment, the molar ratio of the first content to the second content is 1:3.5 to 5. For example, it can be 1:3.5, 1:4, 1:4.5 or 1:5.

[0054] In an optional embodiment, the nutrients forming the cottonseed oil include 13% to 15% protein, 6% to 8% water, and the rest is oil; in the secondary cottonseed oil processing step, the degummed cottonseed oil is added to an alkaline solution and heated to 180° C. to 200° C., the protein in the cottonseed oil reacts with the alkaline solution, the protein condenses to form a solid protein that is separated from the cottonseed oil, and the secondary cottonseed oil is obtained after filtration.

[0055] In an optional embodiment, the temperature of the degumming treatment in the secondary cottonseed oil processing step, the evaporation temperature in the evaporation step, the alkali translocation reaction temperature in the alkali translocation step, the acid oil, the acid oil reaction temperature in the neutralization reaction step and the dehydration temperature in the dehydration fine filtration step are all the same.

[0056] On the other hand, a purified secondary cottonseed oil is provided, and the purified secondary cottonseed oil is purified by any of the above methods.

[0057] The cottonseed oil purification method provided by the present invention is further explained and described below through specific examples.

[0058] Example 1

[0059] Weigh 500kg of raw cotton seeds (with a depilation rate of more than 75%) that have been screened, washed, dried and depilated, and crush them with a crusher. At a temperature of 45°C, add 350kg of depilated cotton seeds, and press them with a press to obtain crude oil. The weight of the crude oil is 250kg. The speed of the press is 10 revolutions per unit. The crude oil is placed in a stainless steel oil filter tank for filtration and slag removal to ensure that the water content is 0.5%. After measurement, the crude cotton oil is metered into a mixing tank, and then into a degumming tank. The degumming kettle is heated to a temperature of 180°C, and the degumming treatment is carried out at a constant temperature for 2 hours, and then the secondary oil is filtered by a vacuum pump. 200 kg of cottonseed oil is added to a glycerin evaporator, heated to 180° C. with steam, a valve of a glycerin evaporator is opened, and the evaporation is performed for 10 minutes, and the second-grade cottonseed oil is dripped into an alkali transposition pot, and the water content of the liquid is reduced from 50% to 70% to about 3%, 1.1 kg of food-grade sodium hydroxide is added, and the temperature in the alkali transposition pot is maintained at 180° C. The reaction time is 3 minutes, phosphorus is converted into neutral phosphate and hydrocarbon, 8 kg of food-grade sodium hydroxide is added, and after reacting for 3 minutes, 40 kg of clean water is added, and the mixture is stirred for 3 minutes until neutralization is ensured. Put the liquid in the reaction pot into the acid oil reaction pot, add 1.63kg of phosphoric acid and 40kg of clean water, stir for 3 minutes, react for 5 minutes, maintain the temperature at 180℃, let the phosphorus become neutral phosphate, and then filter the acid oil reaction pot through a vacuum filter press to obtain 300kg of raw cotton oil, which is then placed in a vacuum dehydration device to obtain cottonseed oil with phosphide and moisture removed, add 0.4kg of citric acid, stir well, dehydrate for secondary dehydration, and when the moisture content is 0.1%, filter press to obtain 230kg of dewaxed oil, which is finely filtered and then put into a vacuum dehydration cylinder to make finished oil. 250kg of raw cotton is used as raw material, and the oil loss is 6.9%.

[0060] Example 2

[0061] Weigh 500kg of raw cotton seeds (with a depilation rate of more than 75%) that have been screened, washed, dried and depilated, and crush them with a crusher. At a temperature of 45°C, add 350kg of depilated cotton seeds, and press them with a press to obtain crude oil. The weight of the crude oil is 320kg. The speed of the press is 10 revolutions per unit. The crude oil is placed in a stainless steel oil filter tank for filtration and slag removal to ensure that the water content is 0.8%. After measurement, the crude cotton oil is metered into a mixing tank, and then into a degumming tank. The degumming kettle is heated to a temperature of 180°C, and the degumming treatment is carried out at a constant temperature for 2 hours, and then the secondary oil is filtered by a vacuum pump. 300 kg of cottonseed oil, the obtained secondary cottonseed oil is put into a glycerol evaporation tank, heated to 200 DEG C with steam, the valve of the glycerol evaporation pipe is opened, and the cottonseed oil is allowed to drip into an alkali transposition pot, and the water content of the liquid is reduced from 50% to 70% to about 3%, 0.75 kg of food-grade sodium hydroxide is added, and the temperature in the alkali transposition pot is maintained at 180 DEG C; the reaction time is 3 minutes, phosphorus is converted into neutral phosphate and hydrocarbon, and 12 kg of food-grade sodium hydroxide is added. After reacting for 3 minutes, 34 kg of clean water is added, and the mixture is stirred for 3 minutes until neutralization is ensured. Put the liquid in the reaction pot into the acid oil reaction pot, add 2.34kg of phosphoric acid and 46kg of clean water, stir for 3 minutes, react for 5 minutes, maintain the temperature at 200℃, let the phosphorus become neutral phosphate, and then filter the acid oil reaction pot through a vacuum filter press to obtain 400kg of raw cotton oil, which is then placed in a vacuum dehydration device to obtain cottonseed oil with phosphide and moisture removed, add 0.5kg of citric acid, stir well, dehydrate for secondary dehydration, and when the moisture content is 0.4%, filter press to obtain 330kg of dewaxed oil, which is finely filtered and then put into a vacuum dehydration cylinder to make finished oil. 350kg of raw cotton is used as raw material, and the oil loss is 4.5%.

[0062] Example 3

[0063] Weigh 500kg of raw cotton seeds (with a delinting rate of more than 75%) that have been screened, washed, dried and delinted, and crush them with a crusher. At a temperature of 45°C, add 350kg of delinted cotton seeds, and press them with a press to obtain crude oil. The weight of the crude oil is 280kg. The crude oil is placed in a stainless steel oil filter tank for filtration and slag removal to ensure that the water content is 0.4%. After measurement, the crude cotton oil is measured and input into a mixing tank, and then into a degumming tank. The degumming kettle is heated to a temperature of 190°C and the degumming treatment is carried out at a constant temperature for 2 hours, and then the secondary cottonseed oil 32 is obtained by vacuum pump pressure filtration. 0kg, put the obtained secondary cottonseed oil into the glycerol evaporator, heat it to 190℃ with steam, open the glycerol evaporation pipe valve, evaporate for 32 minutes, let the cottonseed oil drip into the alkali transfer pot, reduce the liquid water content from 50% to 70% to about 3%, add 1.1kg of food-grade sodium hydroxide, and maintain the temperature in the alkali transfer pot at 190℃; the reaction time is 3 minutes, let phosphorus become neutral phosphate and hydrocarbon, add 9kg of food-grade sodium hydroxide, react for 3 minutes, then add 30kg of clean water, and stir for 3 minutes to ensure neutralization. Put the liquid in the reaction pot into the acid oil reaction pot, add 1.5kg of phosphoric acid and 32kg of clean water, stir for 3 minutes, react for 5 minutes, maintain the temperature at 190℃, let the phosphorus become neutral phosphate, and then filter the acid oil reaction pot through a vacuum filter press to obtain 420kg of raw cotton oil, remove phosphide and water, and then place it in a vacuum dehydration device to obtain cottonseed oil with phosphide and water removed, add 0.3kg of citric acid, stir well, dehydrate for secondary dehydration, dehydrate to 0.7% water, filter press to obtain 328kg of dewaxed oil, fine filter, and then enter the vacuum dehydration cylinder to make finished oil, 350kg of raw cotton seed as raw material, and the oil loss is 4.9%.

[0064] Example 4

[0065] Weigh 500kg of raw cotton seeds (with a depilation rate of more than 75%) that have been screened, washed, dried and depilated, and crush them with a crusher. At a temperature of 45°C, add 350kg of depilated cotton seeds, and press them with a press to obtain crude oil. The weight of the crude oil is 280kg. The crude oil is placed in a stainless steel oil filter tank for filtration and slag removal to ensure that the water content is 0.7%. After measurement, the crude cotton oil is measured and input into a mixing tank, and then into a degumming tank. The degumming kettle is heated to a temperature of 190°C and the degumming treatment is carried out at a constant temperature for 2 hours, and then the secondary cottonseed oil 32 is obtained by vacuum pump pressure filtration. 0kg, put the obtained secondary cottonseed oil into the glycerol evaporator, heat it to 190℃ with steam, open the glycerol evaporation pipe valve, evaporate for 30 minutes, let the cottonseed oil drip into the alkali transfer pot, reduce the liquid water content from 50% to 70% to about 3%, add 1.5kg of food-grade sodium hydroxide, and maintain the temperature in the alkali transfer pot at 190℃; the reaction time is 3 minutes, let the phosphorus become neutral phosphate and hydrocarbon, then add 8kg of food-grade sodium hydroxide, react for 3 minutes, then add 30kg of clean water, and stir for 3 minutes to ensure neutralization. Put the liquid in the reaction pot into the acid oil reaction pot, add 1.5kg of phosphoric acid and 34kg of clean water, stir for 3 minutes, react for 5 minutes, maintain the temperature at 190℃, let the phosphorus become neutral phosphate, and then filter the acid oil reaction pot through a vacuum filter press to obtain 420kg of raw cotton oil, which is then placed in a vacuum dehydration device to obtain cottonseed oil with phosphide and moisture removed, add 0.3kg of citric acid, stir well, dehydrate for secondary dehydration, and when the moisture content is 0.4%, filter press to obtain 328kg of dewaxed oil, and after fine filtration, enter the vacuum dehydration cylinder to make finished oil, with 350kg of raw cotton as raw material and 4.3% oil loss.

[0066] Example 5

[0067] Weigh 500kg of raw cotton seeds (with a depilation rate of more than 75%) that have been screened, washed, dried and depilated, and crush them with a crusher. At a temperature of 45°C, add 350kg of depilated cotton seeds, and press them with a press to obtain crude oil. The weight of the crude oil is 270kg. The speed of the press is 10 revolutions per unit. The crude oil is placed in a stainless steel oil filter tank for filtration and slag removal to ensure that the water content is 0.7% to 0.9%. After measurement, the crude cotton oil is metered into a mixing tank, and then into a degumming tank. The degumming kettle is heated to a temperature of 200°C, and the degumming treatment is carried out at a constant temperature for 2 hours, and then the crude cotton oil is filtered by a vacuum pump to obtain The second-grade cottonseed oil is 340 kg, and the obtained second-grade cottonseed oil is placed in a glycerol evaporation tank, heated to 200° C. with steam, and the valve of the glycerol evaporation pipe is opened to evaporate for 30 minutes, and the cottonseed oil is dripped into an alkali transposition pot to reduce the water content of the liquid from 50% to 70% to about 3%, and the amount of food-grade sodium hydroxide added is 2.1 kg, and the temperature in the alkali transposition pot is maintained at 200° C. The reaction time is 3 minutes, and phosphorus becomes neutral phosphate and hydrocarbon, and then 9 kg of food-grade sodium hydroxide is added. After reacting for 3 minutes, 28 kg of clean water is added, and the mixture is stirred for 3 minutes to ensure neutralization. Put the liquid in the reaction pot into the acid oil reaction pot, add 1.5kg of phosphoric acid and 32kg of clean water, stir for 3 minutes, react for 5 minutes, maintain the temperature at 200℃, let the phosphorus become neutral phosphate, and then filter the acid oil reaction pot through a vacuum filter press to obtain 400kg of raw cotton oil, which is then placed in a vacuum dehydration device to obtain cottonseed oil with phosphide and moisture removed, add 0.5kg of citric acid, stir well, dehydrate for a second time, and when the moisture content is 0.3%, filter press to obtain 346kg of dewaxed oil, which is finely filtered and then put into a vacuum dehydration cylinder to make finished oil. 350kg of raw cotton is used as raw material, and the oil loss is 2.7%.

[0068] In the embodiment of the present invention, the steps of degumming, glycerol evaporation, alkali translocation, acid-oil neutralization reaction and dehydration are adopted to improve the quality of cottonseed oil. After dephosphorization, the phosphorus content is reduced from the original 0.1% to 0.03%, the oxidation phenomenon of the oil during storage is greatly improved, and the water content is reduced from the original 6% to 0.1%. Since the phosphorus is reduced to 0.03%, the bacterial phenomenon of the oil during storage is changed and disappears. During the storage process, the cottonseed oil will not become sour or deteriorate, and can be stored for a long time. There is less waste water and waste alkali liquid, which meets the requirement of not being discharged into the environment. Since the embodiment of the present invention adjusts each process, such as temperature, water volume, reaction time, and the ratio of reactants according to the oil quality, the oil content is increased, and the waste water, waste alkali amount and waste residue in the production process are reduced.

[0069] The embodiment of the present invention generates less waste water and waste alkali solution, and the obtained cottonseed oil is of high quality. A cottonseed oil product containing more than 80% can be refined, and the phosphorus content and water content can be reduced, thereby improving the anti-oxidation performance of the cottonseed oil.

[0070] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A cottonseed oil purification method, characterized in that, include: The steps of extracting raw cotton oil are as follows: pressing, separating and filtering the pretreated cotton seeds in sequence to obtain raw cotton oil; The secondary cottonseed oil processing steps include: heating the raw cotton oil to a preset temperature for primary refining to obtain the third-grade cottonseed oil, degumming the third-grade cottonseed oil, heating the degummed third-grade cottonseed oil to 70° C. to 90° C., adding an alkaline solution, stirring for 30 minutes to 35 minutes, separating the neutral oil by a centrifuge, drying the neutral oil and heating it to 110° C. to 120° C., adding a decolorizing agent and stirring, filtering and separating, heating it to 180° C. to 210° C., and distilling it with saturated steam for 2 hours under a vacuum state to obtain the secondary cottonseed oil; First-grade cottonseed oil processing: Evaporation step: heating the secondary cottonseed oil to 180° C. to 200° C., keeping the temperature constant for 10 to 20 minutes, and continuing to heat the oil to evaporate the glycerin in the secondary cottonseed oil to obtain the secondary cottonseed oil with evaporated glycerin; Alkali translocation step: adding a first content of food-grade sodium hydroxide to the secondary cottonseed oil from which glycerol has been evaporated, stirring and reacting for 3 to 5 minutes; adding a second content of food-grade sodium hydroxide, stirring and reacting for 3 to 5 minutes to obtain an alkali translocation liquid; Acid oil, neutralization reaction step: react the alkali translocation liquid with phosphoric acid, then add water and stir until there is no residue; wherein the mass of the phosphoric acid is 3% to 5% of the mass of the alkali translocation liquid; Dehydration and fine filtration steps: the liquid after acid oil and neutralization reaction is heated to 180°C to 200°C, kept warm for 2 to 3 hours, cooled and filtered, and then first-level fine filtration and second-level fine filtration are carried out in sequence to obtain purified second-level cottonseed oil.

2. The cottonseed oil purification method according to claim 1, characterized in that The degumming treatment time in the secondary cottonseed oil processing step is 15 minutes to 25 minutes.

3. The cottonseed oil purification method according to claim 1, characterized in that The preset temperature of the degumming treatment is 80°C to 90°C.

4. The cottonseed oil purification method according to claim 1, characterized in that The alkaline solution includes food grade sodium hydroxide or potassium hydroxide solution; The molar ratio of the alkaline solution to the cottonseed oil is 1:1 to 1.

05.

5. The cottonseed oil purification method according to claim 1, characterized in that In the base translocation step, the first content is less than the second content; The molar ratio of the primary lime to the first content of calcium oxide is 30:1-3; The molar ratio of the secondary lime to the second content of calcium oxide is 15:1-3.

6. The cottonseed oil purification method according to claim 5, characterized in that: The molar ratio of the first content to the second content is 1:3.5-5.

7. The cottonseed oil purification method according to claim 1, characterized in that: The nutrients that make up cottonseed oil include 13% to 15% protein, 6% to 8% water, and the rest is oil.

8. The cottonseed oil purification method according to claim 1, characterized in that: In the secondary cottonseed oil processing step, the degummed raw cotton oil is added to an alkaline solution and heated to 180° C. to 200° C., the protein in the cottonseed oil reacts with the alkaline solution, the protein condenses to form a solid protein which is separated from the cottonseed oil, and the secondary cottonseed oil is obtained after filtering.

9. The cottonseed oil purification method according to claim 1, characterized in that: The degumming temperature in the secondary cottonseed oil processing step, the evaporation temperature in the evaporation step, the alkali translocation reaction temperature in the alkali translocation step, the acid oil reaction temperature in the acid oil neutralization reaction step and the dehydration temperature in the dehydration fine filtration step are all the same.

10. A purified secondary cottonseed oil, characterized in that: The purified secondary cottonseed oil is obtained by purification using the method described in any one of claims 1-9.

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