CN114729283A

CN114729283A - Continuous soap-free degumming and refining process and equipment for vegetable oil

Info

Publication number: CN114729283A
Application number: CN202080080688.2A
Authority: CN
Inventors: 俞正平; 石芝龙; 王兴国; 陈福彬; 杜坚
Original assignee: Foshan Gentle Mechanical Equipment Co ltd
Current assignee: Foshan Gentle Mechanical Equipment Co ltd
Priority date: 2019-12-04
Filing date: 2020-11-13
Publication date: 2022-07-08
Also published as: WO2021109835A1; CN112899079A

Abstract

The invention provides a degumming process and a device for continuous soap-free degumming of vegetable oil and a vegetable oil refining process. Continuous ultrasound, flocculation precipitation, centrifugal separation and vacuum drying are adopted after acidification and hydration reaction of the traditional degumming process, so that the degummed oil which can be directly used for decolorization processing conditions can be obtained. Alkali is not added in the continuous ultrasonic soap-free degumming reaction process, soapstock and washing wastewater are not generated, free fatty acid in crude oil is not removed in the degumming section, and the high-quality fatty acid is extracted in a post-deacidification tower in the deodorization deacidification section, so that the income is greatly increased. The continuous ultrasonic soap-free degumming process has simple flow, the structure of the complete equipment is simpler than that of the traditional process, the two working sections of hydration degumming and alkali refining in the traditional process can be completely replaced, and the degumming oil which can directly enter the decoloring processing condition can be satisfied. And the loss of phospholipid, fatty acid and neutral oil which are taken away by soapstock formed by the traditional process of the industry through alkali degumming and deacidification forms product recovery, so that the energy conservation, emission reduction and efficiency improvement of the traditional oil processing are realized.

Description

Continuous soap-free degumming and refining process and equipment for vegetable oil

Technical Field

The invention belongs to the field of edible oil processing, and particularly relates to a vegetable oil continuous soap-free degumming and refining process and equipment thereof.

Background

Since the crude vegetable oil contains suspended impurities (such as solid impurities like silt, cake dregs and the like), peptized impurities (such as phospholipid including hydrated phospholipid and non-hydrated phospholipid), oil-soluble impurities (such as free fatty acid and pigment) and water, the crude vegetable oil is easy to hydrolyze, oxidize, rancidity and dullness; during cooking, the food has more foams, peculiar smell and large oil smoke, generates scorched precipitates, influences the smell and the taste of the food and influences the body health. Therefore, the crude oil must be refined to obtain a vegetable oil that meets edible standards.

The refining process of the crude oil generally comprises the steps of degumming, deacidification, decoloration, dewaxing, deodorization and the like. The degumming process is mainly used for removing colloid (i.e. peptized impurities such as phospholipid) and metal ions in the crude oil, and the prior art generally adopts hydration degumming, alkali refining degumming, enzymatic degumming and the like. As the first process of the refining and processing of the crude vegetable oil, the level of the degumming process is the key of the subsequent decolorization, deodorization processing and the quality of the final product. Therefore, a new degumming process needs to be developed for different types of oil raw materials to improve the degumming effect, so that the phosphorus content in the degummed oil reaches 5-10 PPm or even lower, the metal content of iron, magnesium and calcium is generally controlled to be less than 0.2%, and the content of free fatty acid is generally controlled to be less than 0.1%, so as to ensure the refining and decoloring processing of vegetable oil and the processing of subsequent processes, and ensure the quality of oil products.

The hydration degumming is a degumming mode which utilizes the hydrophilicity of peptized impurities such as phospholipid and the like, and adds a certain amount of hot water or electrolyte aqueous solutions such as dilute alkali, salt aqueous solution, phosphoric acid and the like into the crude oil at a certain temperature under stirring to enable the peptized impurities in the crude oil to be coagulated, settled and separated. The substances which are coagulated and settled are limited, and the degumming is not thorough, so that the standard of the degumming oil required by the national standard is difficult to achieve. In contrast, chinese patent application CN102851115A utilizes ultrasonic wave to assist hydration degumming, and uses low-power ultrasonic waves to promote the reaction in the acidification reaction and the hydration reaction respectively under the condition of controlling the stirring rate. However, this method employs intermittent ultrasonic reaction and simultaneous addition of acid, addition of washing water and stirring, requires simultaneous control of the amount of acid and washing water added, and the switching and stirring speed of ultrasonic waves, is complicated in equipment and operation, and inefficient, and is not suitable for industrial scale application.

The alkali refining degumming is that certain amount of phosphoric acid or citric acid is added into heated crude oil to convert non-hydrated phospholipid in oil into hydrated phospholipid, and proper amount of alkali is added to neutralize free fatty acid in oil to produce sodium soap, which is insoluble colloid in oil and thus separated and adsorbed to precipitate phospholipid, protein, mucus, pigment, etc. The alkali-refining degumming is usually carried out after hydration degumming, and as a subsequent process of the hydration degumming, the degumming neutralization oil after the alkali-refining degumming can meet the process requirement of entering the decoloring processing. For example, chinese patent application CN103865639A uses ultrasonic waves to assist the alkali degumming of rice bran oil, and uses four ultrasonic generators to assist the reaction in four stages of acidification, delayed acidification, alkalization neutralization and water washing. However, the process and equipment are complex and costly; the loss is large, and the yield is low; and solid waste (soapstock) and sewage (washing water) can be formed, the treatment cost is high, and the method is not environment-friendly. In actual production, a plurality of oil refineries adopting alkali degumming and soapstock reprocessing plants steal a large amount of sewage in order to save cost, and great damage is caused to the environment.

The enzymatic degumming adopts modern high and new biological engineering technology in oil refining, utilizes a new process of phospholipid hydrolysis in the presence of enzyme, cuts off one fatty acid chain of non-hydrated phospholipid through phospholipase hydrolysis to generate lysophospholipid, and the lysophospholipid has strong hydrophilicity and is conveniently removed through hydration. The enzymatic degumming process is suitable for degumming various vegetable oils, has low oil foot content, is favorable for reducing the consumption of argil in the decolorization process, can partially recycle discharged water in the process, and has little wastewater discharge. However, enzymatic degumming is costly and the properties of the subsequent product are not satisfactory.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a continuous soap-free degumming process for vegetable oil, which is characterized by comprising the following steps of:

s1 acidification reaction: adding an acid to the vegetable oil to be degummed to convert non-hydratable phospholipids in the vegetable oil to hydratable phospholipids, forming a first product;

s2 hydration reaction: adding water to said first product to cause said hydrated phospholipid in said first product to swell by absorbing water to form a second product;

s3 ultrasonic reaction: the second product is treated with ultrasound to form a third product.

Further, the vegetable oil is selected from one or more of soybean oil, corn oil, sunflower seed oil and rice bran oil, the phosphorus content of the vegetable oil is 100-1200 PPm, and the water content is less than 0.2 wt%.

Further, the acid used in the acidification reaction of S1 is one or more selected from citric acid, phosphoric acid, oxalic acid and malic acid.

Further, the water added in the S2 hydration reaction is soft water, the mass of the water is 0.5-1.5% of that of the vegetable oil, and the temperature of the water is 5-10 ℃ higher than that of the vegetable oil.

Further, the ultrasonic reaction step of S3 specifically comprises:

and continuously flowing the second product into the ultrasonic reaction device from the inlet of the ultrasonic reaction device and then continuously flowing out from the outlet of the ultrasonic reaction device, wherein the ultrasonic reaction container generates continuous ultrasonic waves.

Further, the amplitude of the continuous ultrasonic wave is set to be 5 to 60 μm, and the power is set to be 0.5 to 5kW per one group.

Further, the temperature of the S3 ultrasonic reaction is 45-70 ℃; the flow velocity of the vegetable oil in each ultrasonic reaction container is 10-110L/min.

Further, still include:

s4 flocculation reaction: stirring the third product to flocculate the colloids in the third product into micelles to form a fourth product.

Further, the stirring speed in the S4 flocculation reaction is 12-60 r/min.

Further, still include:

s5 separation step: and separating the micelle from the fourth product through centrifugal separation to form a fifth product.

Further, the separation step of S5 specifically includes:

and placing the fourth product in a centrifugal separation device for centrifugal separation, wherein the rotating speed of the centrifugal separation is 4000-8000 r/min, and the temperature is 15-90 ℃.

Further, still include:

s6 drying step: vacuum drying the fifth product to form a sixth product.

The invention also provides a continuous soap-free refining process for vegetable oil, which is characterized by comprising the following steps:

s1 acidification reaction: adding an acid to the crude oil to be degummed to convert non-hydrated phospholipids in the crude oil to hydrated phospholipids, forming a first product;

s2 hydration reaction: adding water to said first product to cause said hydrated phospholipid therein to swell by absorbing water to form a second product;

s3 ultrasonic reaction: treating the second product with ultrasonic waves to form a third product;

s4 flocculation reaction: stirring the third product to flocculate the colloids in the third product into micelles to form a fourth product;

s5 separation step: separating the micelle from the fourth product by centrifugal separation to form a fifth product;

s6 drying step: vacuum drying the fifth product to form a sixth product;

s7 decoloring step: adding a decoloring agent into the sixth product, mixing, and removing color and impurities to form a seventh product;

s8 deodorization and deacidification step: and heating the seventh product at high temperature, introducing steam, and processing by processes such as vacuum extraction, spray trapping and the like to obtain refined and post-acid-trapped vegetable oil and fatty acid products.

Further, the acid used in the acidification reaction of S1 is one or more selected from citric acid, phosphoric acid, oxalic acid and malic acid;

the water added in the S2 hydration reaction is soft water, the mass of the water is 0.5-1.5% of that of the vegetable oil, and the temperature of the water is 5-10 ℃ higher than that of the vegetable oil;

the S3 ultrasonic reaction step specifically comprises: and continuously flowing the second product into the ultrasonic reaction device from an inlet of the ultrasonic reaction device, and then continuously flowing out from an outlet of the ultrasonic reaction device, wherein the ultrasonic reaction container generates continuous ultrasonic waves, and the amplitude of the continuous ultrasonic waves is 5-60 mu m, and the power of the continuous ultrasonic waves is 0.5-5 kW.

The stirring speed in the S4 flocculation reaction is 12-60 r/min;

the S5 separation step specifically comprises the following steps: placing the fourth product in a centrifugal separation device for centrifugal separation, wherein the rotating speed of the centrifugal separation is 4000-8000 r/min, and the temperature is 15-90 ℃;

further, the step of decoloring S7 is performed in two stages, wherein the sixth product is firstly subjected to pre-decoloring by using a used decoloring agent, and then is subjected to secondary decoloring by using a fresh decoloring agent;

the step of deodorizing and deacidifying S8 is carried out in two stages, wherein the first stage of deodorization is carried out at the temperature of 240-255 ℃, and the second stage of acid capture is carried out at the temperature of 250-265 ℃.

The invention also provides main equipment for continuous soap-free degumming of vegetable oil, which comprises an ultrasonic reaction device and a flocculation reaction device, and is characterized in that the inlet of the ultrasonic reaction device is used for the inflow of the vegetable oil for completing the acidification reaction and the hydration reaction, and the flocculation reaction device is connected with the downstream of the ultrasonic reaction device.

Further, the ultrasonic reaction device and the flocculation reaction device are integrated in a whole container.

Further, each ultrasonic reaction container comprises an ultrasonic generator, the ultrasonic generator is used for generating continuous ultrasonic waves, the amplitude of the continuous ultrasonic waves is 5-60 mu m, and the power of each group of the ultrasonic generators is 0.5-5 kW.

Further, the flocculation reaction device comprises a stirring device, and the stirring device can generate stirring action with the rotating speed of 12-60 r/min.

Compared with the prior art, the invention has at least the following beneficial technical effects:

(1) in the degumming process in the prior art, hydrated phospholipid converted by phosphoric acid cannot be well treated, so that only alkaline water can be selectively added for neutralization, and pollutants such as soapstock, washing wastewater and the like are generated, thereby causing environmental pollution. The soap-free degumming process provided by the invention has the advantages that the hydration phospholipid generated by the acidification reaction is subjected to water absorption expansion and flocculation through the cooperation of the acidification reaction, the hydration reaction and the ultrasonic reaction, and is easy to separate. Therefore, in the degumming process of the invention, alkali is not added, so that pollutants such as soapstock and the like are not generated, the problem of environmental pollution is solved, the degumming effect is better than that of the prior art, the phosphorus content in the degummed oil reaches below 10PPm, the requirement of a subsequent decoloring working section and the national standard of edible oil are completely met, and the degummed oil can be stored for a long time and is not easy to deteriorate.

(2) While phosphoric acid is commonly used in the degumming process of the prior art, the degumming process provided by the present invention preferably uses 50% citric acid. Compared with the degumming process in the prior art, the acid amount is less, and the auxiliary material cost is saved (see the auxiliary material dosage comparison table in the specific embodiment for details). In the flocculation reaction device, the citric acid can also change the divalent metal ions such as calcium, magnesium, iron and the like which are combined with the non-hydrated phospholipid and remained in the oil, namely Ca2+, Mg2+ and Fe2+ into a free state, and the citric acid can also chelate the polyvalent metal ions in the oil and move the polyvalent metal ions into the water phase to be removed.

(3) In the vegetable oil refining process in the prior art, because alkali needs to be added in the degumming process step, the problem of environmental pollution is caused, and free fatty acid in the crude oil is neutralized to form soapstock due to the addition of the alkali water, so that waste is caused. In contrast, according to the vegetable oil soap-free refining process provided by the invention, as alkali is not required to be added in the degumming process step, colloid phospholipid in oil can be basically removed, and free fatty acid in the degummed oil is retained, and a high-quality fatty acid product is recovered in the acid capturing step after the final process of the continuous soap-free refining process, so that the neutral oil loss when the free fatty acid is saponified is reduced, the oil processing income is greatly increased, and the water washing sewage discharge of the traditional process is completely avoided.

(4) The degumming process equipment provided by the invention clearly separates the steps of acidification, hydration, ultrasound, flocculation, centrifugal separation and the like from the equipment, and reduces three centrifuges which are required to be configured in the traditional degumming and deacidification process into one centrifuge, so that the equipment is less, the operation is simple, the occupied space is small, the investment of fixed assets is less, the labor cost and the operation cost are low, and the extremely high economic benefit is achieved.

(5) The ultrasonic reaction device for the vegetable oil degumming process provided by the invention adopts high-power continuous ultrasonic waves, and one or more ultrasonic reaction containers are connected in series and/or in parallel by controlling the flow rate of the vegetable oil in each ultrasonic reaction container, so that the processing time of the process is shortened compared with that of the traditional process, the requirements of different vegetable oil types and different production capacities can be flexibly met, and the continuous and efficient production can be realized.

Drawings

FIG. 1 is a schematic flow diagram of a vegetable oil continuous soapless degumming process according to a preferred embodiment of the present invention;

FIG. 2 is a schematic diagram of a vegetable oil continuous soapless degumming system according to a preferred embodiment of the present invention;

FIG. 3 is a schematic diagram of a vegetable oil continuous soapless degumming system according to another preferred embodiment of the present invention;

FIG. 4 is a schematic structural diagram of the ultrasonic flocculation apparatus of FIG. 3;

FIG. 5 is a schematic diagram of the distribution of an oil distributor and an ultrasonic reaction vessel in the ultrasonic flocculation apparatus according to a preferred embodiment of the present invention;

FIG. 6 is a schematic diagram of the distribution of an oil distributor and an ultrasonic reaction vessel in an ultrasonic flocculation apparatus according to another preferred embodiment of the present invention.

Detailed Description

The following examples are given to illustrate the present invention in detail, and the following examples are given to illustrate the detailed embodiments and specific procedures of the present invention, but the scope of the present invention is not limited to the following examples.

In a preferred embodiment, the flow and system schematic of the vegetable oil continuous soap-free degumming process of the present invention are shown in fig. 1 and fig. 2, respectively, and comprise the following steps:

s1, heating the vegetable oil crude oil by a plate-type or tube-type heat exchanger (not shown in the figure), then feeding the heated vegetable oil crude oil into a crude oil tank 1, adding acid in an acid tank 2, and then introducing the heated vegetable oil crude oil into an acidification reaction device 3 for acidification reaction to convert non-hydrated phospholipid in the vegetable oil crude oil into hydrated phospholipid; after the treatment of S1, the vegetable oil crude oil with hydrated phospholipid is a first product.

The flow of the crude oil can be measured by a crude oil flowmeter 12 and adjusted by a crude oil adjusting valve 11; the flow of the added acid can be measured by an acid flow meter 22 and adjusted by an acid adjusting valve 21; the crude oil is added with acid and then is uniformly mixed by an acid mixer 23, and enters the acidification reaction device 3 from an inlet below the acidification reaction device 3; the acidification reaction is carried out under the stirring of an acid stirrer 31, and the vegetable oil after the acidification reaction is discharged from an outlet above the acidification reaction device 3; the vegetable oil after the acidification reaction can be supplemented with heat by the first heater 32, so that the temperature of the vegetable oil is kept in a temperature range required by the next hydration reaction, and the first heater 32 is linked with the first temperature sensor 33, so that the automatic control of the temperature can be realized;

in a preferred embodiment of the present invention, the acid used in the acidification reaction is preferably citric acid with a concentration of 50%, and in other embodiments, one or a mixture of citric acid, phosphoric acid, oxalic acid and malic acid can also be used.

S2, adding water into the vegetable oil after acidification reaction through a water tank 4, introducing the vegetable oil into a hydration reaction device 5, and performing hydration reaction to ensure that the hydrated phospholipid in the vegetable oil absorbs water and expands, and is easy to settle and separate out; after the treatment of S2, the vegetable oil crude oil with the hydrated phospholipid after water swelling is taken as a second product.

Wherein, the flow of the added water can be measured by a water flow meter 42 and adjusted by a water adjusting valve 41; after being added with water, the vegetable oil is uniformly mixed by a water mixer 43 and enters the hydration reaction device 5 from an inlet below the hydration reaction device 5; the hydration reaction is carried out under the stirring of the water stirrer 51, and the vegetable oil after the hydration reaction is discharged from an outlet above the hydration reaction device 5; the vegetable oil after hydration reaction can be supplemented with heat by the second heater 52, so that the temperature of the vegetable oil is kept in a temperature range required by the next ultrasonic reaction, and the second heater 52 is linked with the second temperature sensor 53, so that the automatic control of the temperature can be realized;

s3, continuously flowing the vegetable oil after hydration reaction into the ultrasonic reaction device 8 from the inlet of the ultrasonic reaction device 8, continuously flowing the vegetable oil through one or more ultrasonic reaction containers in the ultrasonic reaction device 8 for ultrasonic reaction, and continuously flowing the vegetable oil out from the outlet of the ultrasonic reaction device 8 so that water and colloid in the vegetable oil are easy to flocculate into micelles; the vegetable oil is not stirred during the ultrasonic reaction; after the treatment of S3, the crude vegetable oil with the hydrated phospholipid after water swelling is passed through the continuous ultrasonic wave to obtain a third product.

S4, introducing the vegetable oil after the ultrasonic reaction into a flocculation reaction device 9, and stirring at low speed by a flocculation stirrer 91 to flocculate water and colloid in the vegetable oil into gel masses; the flocculated vegetable oil can be supplemented with heat by the third heater 62, so that the temperature of the vegetable oil is kept in a temperature range required by next centrifugal separation, and the third heater 62 is linked with the third temperature sensor 63, so that the automatic control of the temperature can be realized; and after the treatment of S4, the flocculated vegetable oil containing the micelles is a fourth product.

S5, introducing the flocculated vegetable oil into a centrifugal separation device, such as a centrifuge, and performing centrifugal separation to remove flocculated micelles therein to obtain degummed crude oil, namely a fifth product; and the flocculated micelle separated from the fifth product is oil residue, the main component of the flocculated micelle is phospholipid, and the phospholipid with certain economic benefit is obtained after evaporation, concentration and drying by a film evaporator.

S6, introducing the degummed oil into a vacuum drying device for vacuum drying to remove residual moisture, so as to obtain a dry degummed oil product which can directly enter a decoloring working section under processing conditions; and after the treatment of S6, removing the gum and residual water to obtain a sixth product.

In the steps and the device, the ultrasonic reaction and the flocculation reaction are the key points of the invention. In another preferred embodiment, as shown in FIG. 3, the ultrasonic reaction device 8 and the flocculation reaction device 9 can be integrated into a large container to form an integrated ultrasonic flocculation device 6, the specific structure of which is shown in FIG. 4.

An oil distributor 7 is arranged above the ultrasonic flocculation device 6, and an oil distributor inlet 71 is arranged above the oil distributor 7 and is also an inlet of the whole ultrasonic flocculation device 6; the vegetable oil after acidification reaction and hydration reaction enters the ultrasonic flocculation device 6 from an oil distributor inlet 71, is subjected to pressure relief by a baffle 73 and then flows out from an oil distributor outlet 72 below the oil distributor 7; flows into the ultrasonic reaction vessel 84 from an ultrasonic reaction vessel inlet 81 below the ultrasonic reaction vessel 84; an ultrasonic generator 83 is arranged in the ultrasonic reaction container 84 and can emit continuous ultrasonic waves, and the vegetable oil flows out from an ultrasonic reaction container outlet 82 above the ultrasonic reaction container 84 after ultrasonic reaction and flows into the flocculation reaction device 9; a flocculation stirrer 91 is arranged in the flocculation reaction device 9, and the flocculation stirrer 91 is provided with a blade 93 rotating at a low speed; meanwhile, the flocculation reaction device 9 is also provided with cooling pipes 92 around to reduce the temperature in the flocculation reaction device 9, so as to facilitate the flocculation reaction; the cooling pipe 92 has a cooling liquid inlet 921 and a cooling liquid outlet 922; the flocculated vegetable oil flows out of the whole ultrasonic flocculation device 6 from an outlet below the flocculation reaction device 8 and enters a centrifugal separation device; in addition, the oil distributor 7, the ultrasonic reaction device 8 and the flocculation reaction device 9 in the ultrasonic flocculation device 6 are all communicated with the outside through the air pipe 61 to keep the air pressure inside the devices to be basically consistent with the atmospheric pressure.

It should be noted that, in fig. 4, for the sake of clarity of illustration, the ultrasonic reaction apparatus 8 only shows one ultrasonic reaction container 84, and actually, the ultrasonic reaction container 84 may be one or more. The processing capacity of the ultrasonic reaction device 8 per unit time can be improved by connecting a plurality of ultrasonic reaction containers 84 in parallel, that is, the productivity is improved; and the plurality of ultrasonic reaction containers 84 are connected in series to promote the ultrasonic reaction to be more thorough, and the method is suitable for the condition that the phosphorus content of the crude oil is higher. For example, as shown in fig. 5, an oil distributor 7 is connected to eight ultrasonic reaction vessels 84 and simultaneously distributes oil to the eight ultrasonic reaction vessels 84, and the eight ultrasonic reaction vessels 84 are connected in parallel. For another example, as shown in fig. 6, an oil distributor 7 is connected to eight ultrasonic reaction vessels 84 and distributes oil to the eight ultrasonic reaction vessels 84 at the same time, and the eight ultrasonic reaction vessels 84 are respectively connected in series with one ultrasonic reaction vessel 84, so that a group of two ultrasonic reaction vessels 84 connected in series is formed, and the eight groups are connected in parallel.

As a complete vegetable oil refining process, the continuous soap-free refining process for vegetable oil provided by the invention comprises the degumming process from S1 to S6, and also comprises the following steps:

s7: and (3) decoloring: the degummed oil obtained after the completion of the treatment of S6 is used as the oil to be decolored. Heating the oil to be decolorized to 90-120 ℃, adding a fresh decolorizing agent for mixing, wherein the amount of the fresh decolorizing agent is 0.5-5% of the weight of the oil to be decolorized, and stirring and reacting in a decolorizing reaction tank for 15-60 min. Wherein, the heating mode of the oil to be decolorized can be heating and temperature rising through a plate heat exchanger, a tubular heat exchanger or a spiral heat exchanger; the decolorizing agent can be selected from bleaching earth, or one or more of activated clay, activated carbon and attapulgite; the stirring means may be mechanical stirring or steam stirring. The decolored oil after being treated by S7 and the decolored agent is removed by filtration is a seventh product.

The oil to be decolorized of the next batch can be subjected to pre-decolorization treatment by the once-used decolorizing agent, and the oil to be decolorized after the pre-treatment can be better decolorized by adding fresh decolorizing agent. Especially for vegetable oil with darker color, the decolorizing effect is more obvious.

S8: deodorizing and deacidifying: the decolorized oil treated in S7 is used as the oil to be deodorized. And after the temperature of the oil to be deodorized is raised to 240-255 ℃, introducing steam with the weight of 0.3-1.5% of the weight of the decolored oil into a deodorization tower under the condition that the vacuum degree of an absolute pressure meter is less than 2.5mbar for carrying out steam stripping deodorization reaction for 40-90 minutes. Then acid capture is mainly carried out in an acid removal tower, the deodorized vegetable oil is heated to 250-265 ℃, and the deacidification time is controlled to be 15-30 minutes; the whole continuous soap-free refining process is completed through the treatment of S8.

Examples 1 to 18

Examples 1-18 raw material was crude soybean oil, degummed according to the above procedure and the following parameters:

s1 acidification reaction: the added acid is citric acid with the concentration of 50 percent, the adding amount of the acid is 0.2 percent of the mass of the crude oil, the rotating speed of a mixer is 2900r/min, the acidification reaction temperature is 45-70 ℃, the acidification reaction time is 30min, and the stirring speed is 60 r/min;

s2 hydration reaction: adding deionized water at 45-75 ℃, wherein the water addition amount is 1.0 percent of the mass of the crude oil, the rotating speed of a mixer is 1000r/min, the hydration reaction time is 10min, and the stirring speed is 40 r/min;

s3 ultrasonic reaction: as shown in the following table;

s4 flocculation reaction: the flocculation temperature is 45-75 ℃, the flocculation time is 30min, and the stirring speed is 12 r/min;

s5 centrifugal separation: the centrifugal speed is 5000r/min, and the centrifugal temperature is 50 ℃;

s6 vacuum drying: the vacuum drying device is a desolventizing dryer with the vacuum degree of 80 mbar;

the phosphorus content of the degummed oils obtained in examples 1 to 18 is shown in the following table:

examples 19 to 36

Examples 19-36 raw materials were crude corn oil degummed according to the procedure described above and the following parameters:

s3 ultrasonic reaction: as shown in the following table;

s4 flocculation reaction: the flocculation temperature is 45-70 ℃, the flocculation time is 30min, and the stirring speed is 12 r/min;

s5 centrifugal separation: the centrifugal speed is 5000r/min, and the centrifugal temperature is 65 ℃;

the phosphorus content of the degummed oils obtained in examples 19 to 36 is shown in the following table:

examples 37 to 54

Examples 37-54 raw material was sunflower oil crude oil that was degummed according to the above procedure and the following parameters:

s3 ultrasonic reaction: as shown in the following table;

s5 centrifugal separation: the centrifugal speed is 5000r/min, and the centrifugal temperature is 55 ℃;

the phosphorus content of the degummed oils obtained in examples 37 to 54 is shown in the following table:

examples 55 to 72

Examples 55-72 raw material was rice bran oil crude oil degummed according to the above procedure and the following parameters:

s2 hydration reaction: adding deionized water at 45-70 ℃, wherein the water addition amount is 1.0 percent of the mass of the crude oil, the rotating speed of a mixer is 1000r/min, the hydration reaction time is 10min, and the stirring speed is 40 r/min;

s3 ultrasonic reaction: as shown in the following table;

s5 centrifugal separation: the centrifugal speed is 5000r/min, and the centrifugal temperature is 70 ℃;

the phosphorus content of the degummed oils obtained in examples 55-72 is shown in the following table:

the embodiment shows that the degumming effect is very obvious by adopting the continuous soap-free degumming process of the vegetable oil, the phosphorus content of the degummed oil can basically reach below 10PPm, and the degummed oil completely meets the requirements of a subsequent decoloring working section and the national standard of edible oil.

It should be noted that the continuous soap-free degumming process and the continuous soap-free refining process for vegetable oil provided by the invention are not only suitable for oils in the above embodiments, but also can include crude oils such as soybean oil, corn oil, sunflower seed oil, rice bran oil and the like with phosphorus content of 100-1200 PPm and water content of less than 0.2 wt%. In the soft water added in the hydration step, although the mass of the soft water is 1% of the mass of the vegetable oil in the above embodiments, in other embodiments, the mass of the soft water may be adjusted within a range of 0.5 to 1.5% of the mass of the vegetable oil as needed.

Compared with the alkali refining degumming and super wet hydration degumming in the prior art, the continuous soap-free degumming process has the advantages of less required added auxiliary materials, lower temperature, lower cost, more energy conservation, obvious cost advantage and economic benefit; and does not produce solid wastes such as sewage, soapstock and the like, thereby having remarkable environmental protection benefit.

The comparison of the continuous soap-free degumming process of the present invention with the prior art in terms of the addition of auxiliary materials is shown in the following table:

compared with the advanced super wet degumming process in the prior art, the continuous soap-free degumming process has the following production cost difference estimation table:

from the above table, the super wet degumming process costs 16.37 yuan per ton of oil, whereas the continuous soap-free degumming process of the present invention costs 7.14 yuan per ton of oil, with a difference of 9.23 yuan per ton of oil. Taking the yield of 300TPD as an example, the process can save the cost by 2768.68 RMB/day, namely 8.3 RMB/month and 99.67 RMB/year. If the phospholipid, free fatty acid, neutral oil and the like which are taken away by the soapstock formed by the traditional degumming and deacidification process are all recycled according to the technology of the invention, the benefit of the invention is very considerable.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

A continuous soap-free degumming process for vegetable oil is characterized by comprising the following steps:

s1 acidification reaction: adding an acid to the vegetable oil to be degummed to convert non-hydratable phospholipids in the vegetable oil to hydratable phospholipids, forming a first product;

s2 hydration reaction: adding water to said first product to cause said hydrated phospholipid in said first product to swell by absorbing water to form a second product;

s3 ultrasonic reaction: the second product is treated with ultrasound to form a third product.
The continuous soap-free degumming process for vegetable oils as claimed in claim 1, wherein said vegetable oil is selected from one or more of soybean oil, corn oil, sunflower oil, rice bran oil, said vegetable oil having a phosphorus content of 100 to 1200PPm and a water content of less than 0.2 wt%.
The continuous soap-free degumming process for vegetable oils according to claim 2, wherein the acid used for the acidification reaction of S1 is selected from one or more of citric acid, phosphoric acid, oxalic acid, malic acid.
The continuous soap-free degumming process for vegetable oils according to claim 3, wherein said water added in said S2 hydration reaction is soft water, the mass of said water is 0.5-1.5% of the mass of said vegetable oil, and the temperature of said water is 5-10 ℃ higher than the temperature of said vegetable oil.
The continuous soap-free degumming process for vegetable oils according to claim 4, wherein said S3 ultrasonic reaction step comprises:

the second product is continuously flowed through a continuous ultrasonic wave that is continuously emitted.
The continuous soap-free degumming process for vegetable oils according to claim 5, wherein the amplitude of said continuous ultrasound is set to 5 to 60 μm and the power is set to 0.5 to 5kW per group.
The continuous soap-free degumming process for vegetable oils according to claim 6, wherein the temperature of the S3 ultrasonic reaction is 45-70 ℃; the flow speed of the vegetable oil flowing through the ultrasonic waves is 10-110L/min.
The continuous soap-free degumming process for vegetable oils according to claim 7, further comprising:

s4 flocculation reaction: stirring the third product to make the colloid and the water in the third product gel into a gel mass to form a fourth product.
The continuous soap-free degumming process for vegetable oils according to claim 8, wherein the stirring rate in the S4 flocculation reaction is 12-60 r/min.
The continuous soap-free degumming process for vegetable oils according to claim 9, further comprising:

s5 separation step: and the fourth product is separated from the micelle through centrifugal separation to form a fifth product.
The continuous soap-free degumming process for vegetable oils according to claim 10, wherein said S5 separation step comprises:

and carrying out centrifugal separation on the fourth product, wherein the rotating speed of the centrifugal separation is 4000-8000 r/min, and the temperature is 15-90 ℃.
The continuous soap-free degumming process for vegetable oils according to claim 11, further comprising:

s6 drying step: vacuum drying the fifth product to form a sixth product.
A continuous soap-free refining process for vegetable oil is characterized by comprising the following steps:

s1 acidification reaction: adding an acid to the crude oil to be degummed to convert non-hydrated phospholipids in the crude oil to hydrated phospholipids, forming a first product;

s2 hydration reaction: adding water to said first product to cause said hydrated phospholipid therein to swell by absorbing water to form a second product;

s3 ultrasonic reaction: treating the second product with ultrasonic waves to form a third product;

s4 flocculation reaction: stirring the third product to flocculate the colloids in the third product into micelles to form a fourth product;

s5 separation step: separating the micelle of the fourth product by centrifugal separation to form a fifth product;

s6 drying step: vacuum drying the fifth product to form a sixth product;

s7 decoloring step: adding a decolorizing agent into the sixth product, mixing, and removing the color and impurities of the vegetable oil to form a seventh product;

s8 deodorization and deacidification step: and heating the seventh product at a high temperature, introducing water vapor, and matching with processes such as vacuum pumping and spray trapping to obtain refined and post-acid-trapped vegetable oil and fatty acid products.
The continuous soap-free refining process for vegetable oil as claimed in claim 13,

the acid used in the acidification reaction of S1 is one or more selected from citric acid, phosphoric acid, oxalic acid and malic acid;

the water added in the S2 hydration reaction is soft water, the mass of the water is 0.5-1.5% of the mass of the vegetable oil, and the temperature of the water is 5-10 ℃ higher than that of the vegetable oil;

the S3 ultrasonic reaction step comprises the following steps: continuously flowing the second product into an ultrasonic reaction device from an inlet of the ultrasonic reaction device, and then continuously flowing out from an outlet of the ultrasonic reaction device, wherein the ultrasonic reaction container generates continuous ultrasonic waves, the amplitude of the continuous ultrasonic waves is 5-60 mu m, and each group of power is 0.5-5 kW;

the stirring speed in the S4 flocculation reaction is 12-60 r/min

The S5 separating step includes: and carrying out centrifugal separation on the fourth product, wherein the rotating speed of the centrifugal separation is 4000-8000 r/min, and the temperature is 15-90 ℃.
The continuous soap-free refining process for vegetable oil as claimed in claim 14,

the step of S7 decoloring is carried out in two stages, the sixth product is firstly subjected to pre-decoloring by utilizing the recycled decoloring agent, and then the sixth product is subjected to secondary decoloring by utilizing a fresh decoloring agent;

the step of deodorizing and deacidifying S8 is carried out in two stages, wherein the first stage of deodorization is carried out at the temperature of 240-255 ℃, and the second stage of acid capture is carried out at the temperature of 250-265 ℃.
The continuous vegetable oil soap-free degumming equipment comprises an ultrasonic reaction device and a flocculation reaction device, and is characterized in that vegetable oil for completing acidification reaction and hydration reaction flows into an inlet of the ultrasonic reaction device, and the flocculation reaction device is connected to the downstream of the ultrasonic reaction device.
The continuous soap-free degumming apparatus for vegetable oils according to claim 16, wherein said ultrasonic reaction means and said flocculation reaction means are integrated in a container to form an integrated ultrasonic flocculation reaction apparatus.
The plant oil continuous soap-free degumming apparatus according to claim 17, wherein said ultrasonic reaction means comprises one or more ultrasonic reaction vessels and ultrasonic generators corresponding to each of said ultrasonic reaction vessels, and a plurality of sets of said ultrasonic reaction vessels and said ultrasonic generators are connected in series or in parallel.
The plant oil continuous soap-free degumming apparatus according to claim 18, wherein said ultrasonic generator is arranged in said ultrasonic reaction vessel, said ultrasonic generator is used for generating continuous ultrasonic waves with amplitude of 5-60 μm and power of 0.5-5 kW per group.
The plant oil continuous soap-free degumming equipment according to claim 19, wherein said flocculation reaction device comprises a stirring device configured to stir at a rotation speed of 12-60 r/min.