JP2003119486A - Method for separating and recovering used clay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for separating and recovering an oil and fat and an inorganic adsorbent by centrifuging the inorganic adsorbent used for a decoloring purification treatment and mostly disposed of just after the decoloring purification treatment. SOLUTION: The method for separating and recovering the oil and fat and the inorganic adsorbent comprises centrifuging a mixed liquid of the oil and fat with the inorganic adsorbent just after the decoloring purification treatment and continuously separating and recovering the oil and fat from the inorganic adsorbent. The mixed liquid of the oil and fat with the inorganic adsorbent just after the decoloring purification treatment is cooled to 60-90 deg.C and then continuously centrifuged by 6,000-12,000 centrifugal effects at 1,000-6,000 L/h throughput.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a mixed liquid of an edible oil / fat and an inorganic adsorbent immediately after an animal / vegetable oil / fat is subjected to a decolorization purification treatment in the process of refining an edible oil / fat. The present invention relates to a method of separating and recovering with a yield.

[0002]

In the production of soybean oil, corn oil, linseed oil, castor oil and other edible oils and fats, crude crude oil collected from raw materials is degummed and deoxidized to obtain phospholipids, fatty acids which are impurities, After removing a trace amount of impurities such as heavy metals, decolorizing and refining with an inorganic adsorbent such as activated clay (acid clay), activated carbon, diatomaceous earth, and silica-based adsorbents to remove the coloring substances contained in oil and Other trace impurities are generally removed, and decolorizing and refining treatment with activated clay is generally used.

In decolorizing and purifying oils and fats using an inorganic adsorbent, a method of adding an inorganic adsorbent to an oil and heating and stirring under vacuum to adsorb and separate impurities such as pigments in the oil and fat is widely adopted. The inorganic adsorbent that has adsorbed impurities such as pigments is filtered by a filter device and discharged as a waste inorganic adsorbent in cake form. A large amount of oil content of about 40 to 80% by mass is usually attached to the waste inorganic adsorbent discharged in a cake form, and the adhering oil content is subjected to a purging process (blowing process) using air, steam, nitrogen gas, or the like. Although it is recovered as much as possible by performing the above step), the inorganic adsorbent after the purging process usually still has about 30 to 40% by mass of oil attached.

A part of the waste inorganic adsorbent to which fats and oils are attached is used as a building aggregate, a fermentation aid in the production of compost, and the like. However, in the application of building aggregate, the oil content in the waste inorganic adsorbent becomes an obstacle, and the function as aggregate is often poor. Also, in the application as a fermentation aid for compost production,
Since it is used as an additive, the amount used is extremely small. In addition, when a waste inorganic adsorbent having fats and oils attached thereto is used as a fermentation aid for compost production, there is a problem that plant growth inhibition is likely to occur due to oxidation of fats and oils contained therein.
Therefore, at present, the use as a building aggregate or a fermentation aid is not an effective application field of a large amount of discharged fat-inorganic waste inorganic adsorbent.

Therefore, most of the waste inorganic adsorbents containing fats and oils are incinerated as industrial wastes alone or mixed with other wastes for incineration and discarded as ash, or fats and oils are discarded. It is disposed of in the state in which it was adhered, or it is degreased and landfilled for disposal. However, incineration has environmental problems such as loss of oil and fat resources and air pollution due to incineration, and landfill also has environmental problems such as deterioration of soil environment due to large amounts of oil and fat. There has been a strong demand for more effective treatment of agents.

Under the circumstances as described above, waste inorganic adsorbents adhering and containing fats and oils have been reused, and used for decolorizing and refining treatment of animal and vegetable fats and oils both in Japan and abroad. Various studies have been made on the reuse of the used inorganic adsorbent. Conventionally, the used inorganic adsorbents can be reused by passing crude oil or deoxidized oil while leaving the used inorganic adsorbent in the filter, or by removing the used inorganic adsorbent from the filter. Alternatively, there is a method of recycling by mixing with deoxidized oil.

However, the method (1) requires a plurality of automatic filters for automation, which increases the equipment cost. There was a problem with this method, such as the deterioration of the work environment due to the dust generated when removing the inorganic adsorbent cake from the filter, and the risk of ignition of the used inorganic adsorbent containing oil and fat due to contact with air. .

Although there are the problems mentioned above, the treatment cost of the used inorganic adsorbent tends to increase year by year,
Socially, it has become essential to reduce, reuse, and recycle waste.

On the other hand, regarding the separation and removal of the solid adsorbent by the centrifugal separation method, Japanese Patent Application Laid-Open No. 10-245586 discloses a process for producing diesel fuel oil from waste cooking oil, in which impurities are adsorbed. Disclosed is a step performed by a centrifugal separation method for separating the solid adsorbent from the mixture of the solid adsorbent and the light liquid, but since alcohol is used for diesel fuel, the difference in specific gravity from the solid adsorbent is large. , In order to efficiently separate the adsorbent used,
A particle size of 0.01 mm to 5 mm is used. On the other hand, activated clay that is often used for decolorizing and refining edible oils is 1-25
It is about 0 μm in size, and the purpose of recovery is only for the light liquid, and there is no mention of efficient recovery of oils and fats and inorganic adsorbents.

As described above, the reuse of the used inorganic adsorbent has been attracting attention for a long time, but in the present situation, there is practically no good measure other than improving the method using the filter. is there. From this point, the inorganic adsorbent used for the decolorization purification treatment can be easily and safely separated and recovered at low cost,
In addition, there is a demand for a method of recovering fats and oils with high purity and high yield, but the fact is that a sufficiently satisfactory method has not been obtained.

[0011]

DISCLOSURE OF THE INVENTION The present invention provides a method for separating and recovering oil and fat and an inorganic adsorbent immediately after decolorizing and refining treatment with high yield and high purity, without lowering productivity and safely and at low cost. It is in.

[0012]

[Means for Solving the Problems] The inventors of the present invention have conducted diligent research, paying attention to a centrifugal separation technique generally used for a separation operation. Initially, in the separation method by centrifugation, since the amount of the inorganic adsorbent added is as large as 1.0 to 3.0% by weight with respect to the oil and fat, a separation effect comparable to that of a filter, damage due to clogging and wear inside the centrifuge, etc. There were concerns about the problem, but by adjusting the specific conditions, these problems were solved, and the content of the inorganic adsorbent in the oil and fat was the same as that of the current filtration method from the mixture of decolorized and refined oil and the inorganic adsorbent. We have established a technique to recover at a concentration of less than that. The recovered inorganic adsorbent is
It was found that about 50% of the color tone to be originally removed can be decolorized by adding it to the raw material oil or the deoxidized oil, and it is sufficiently suitable for reuse.

That is, the first aspect of the present invention relates to a method for separating and recovering fats and oils and inorganic adsorbents, which comprises centrifuging a mixed liquid of fats and oils and inorganic adsorbents after the decolorization purification treatment.

A preferred embodiment is characterized in that (1) after the decolorizing and refining treatment, the mixed solution of oil and fat and the inorganic adsorbent is continuously centrifuged, and (2) after the decolorizing and refining treatment,
Centrifugal effect 6000-120 with mixed liquid of oil and fat and inorganic adsorbent
00 and 1000 to 6000 L / hr for continuous centrifugation, (3) the temperature of the mixed solution of oil and fat and the inorganic adsorbent after the decolorizing and refining treatment is 60 to 90 ° C.
And (4) the inorganic adsorbent is activated clay, which relates to the method for separating and recovering the oil and fat and the inorganic adsorbent.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention separates and collects fats and oils and inorganic adsorbents by centrifuging a mixed liquid of fats and oils and inorganic adsorbents immediately after decolorization and purification treatment.

The decolorizing and refining treatment referred to in the present invention refers to a step of adjusting the color tone of the steps of refining animal and vegetable oils and fats, in which an inorganic adsorbent is used. The conditions of the decolorizing and refining treatment are normal conditions and there is no problem. Although it depends on the expected degree of decolorization, generally, about 1.0 to 3.0% by weight of an inorganic adsorbent is added to fats and oils, and about 80 to 1
It is performed by stirring at 20 ° C.

The fats and oils in the present invention are not particularly limited as long as they can be used for food, and specifically, soybean oil, rapeseed oil, palm oil, palm kernel oil, coconut oil, corn oil, sunflower oil and the like. Animal fats and oils such as vegetable fats, fish oils, pork fats, and beef fats, and the like, and one or a mixture of two or more thereof may be used.

The inorganic adsorbent in the present invention is not particularly limited as long as it has an adsorbing power, and specific examples thereof include activated clay (acid clay), activated carbon, diatomaceous earth, silica-based adsorbents and the like. Above all, activated clay is preferable because the effect of the present invention is easily exhibited. The particle size of the inorganic adsorbent is also not particularly limited, but is preferably 1 to 250 μm, more preferably 10 to 150 μm. It goes without saying that an inorganic adsorbent having a large particle size can be easily separated, but in the present application, the separation effect is apparent in the inorganic adsorbent having a relatively small particle size.

In the present invention, it is preferable to centrifuge the mixture of the decolorized and refined oil and fat and the inorganic adsorbent at 60 to 90 ° C. When the temperature is within this range, the oil or fat is not crystallized, and the deterioration of the oil or fat can be minimized. Further, when the temperature is 100 ° C. or lower, it is not necessary to use a centrifugal separator having a heat-resistant specification, and the facility cost can be reduced, which is preferable. The method of centrifugation may be a batch method or a continuous method, but the continuous method is preferable for industrially performing the decolorization purification treatment. Specific examples of the continuous centrifugal separator include Alfa Laval and Westfalia disk-type centrifugal separators, but the centrifugal effect is limited to these as long as they satisfy the conditions of the present application. It is not done. The conditions for centrifugation are the centrifugal effect of 6000 to 12000.
It is preferable that the treatment is performed at 1000 to 6000 L / hr.
The treatment of 00 to 3000 L / hr is more preferable. The centrifugal effect mentioned here is one of the parameters representing the capacity of the centrifugal separator, and is represented by a value obtained by dividing the centrifugal acceleration [γω ² ] by the gravitational acceleration [g]. Here, γ is the radius of gyration (m), ω is the angular velocity (rad / sec), and g is the acceleration of gravity (m / sec ² ). By carrying out in such a range, both the oil and fat after the decolorization purification and the inorganic adsorbent can be recovered in high yield. Therefore, the number of inorganic adsorbent particles in the separated oil and fat is very small. Further, according to the method of the present application, it is possible to recover about 30 to 40% by weight of fats and oils that have been disposed of while being attached to the used clay in the conventional method without discarding, so that an improvement in yield can be expected.

When the recovered inorganic adsorbent is reused, its decolorizing ability is maintained at about 50% of that of the new inorganic adsorbent. That is, although it depends on the type of fats and oils or inorganic adsorbents, for example, in the case of activated clay, the color tone that should be reduced from the color tone of the raw material oil or the deoxidized oil to the color tone of the decolorized refined treated oil by using activated clay was set to 100%. In this case, if the same amount of recovered used clay is added to the feed oil or deoxidized oil, it will be about 50
% Can be decolorized. The color tone was measured with a Robibond colorimeter. Therefore, the addition amount of the activated clay used for decolorization is 100 times that of the conventional method.
%, It can be reduced by about 40%. When the amount of activated white clay used is reduced by about 40%, the cost of processing used white clay can be reduced.

The separation and recovery method using this centrifuge is not limited to the used white clay generated from the decolorizing and refining treatment of animal and vegetable fats and oils, and can be used for separating and recovering the used white clay generated when refining mineral oil. It goes without saying that it is also applicable.

[0022]

The present invention will be described in more detail with reference to specific examples, but the present invention is not limited thereto. (Examples 1 to 3, Control Examples 1 to 3) Cottonseed oil (Example 1),
Beef tallow (Example 2) and palm oil (Example 3) were mixed with 2.0, 1.0, and 1.5% by weight of activated clay, respectively, at cottonseed oil 105 ° C, beef tallow 95 ° C, and palm oil 120 ° C, respectively. After decolorizing for about 20 minutes, a flow rate of 250 was applied to a centrifuge (Alfa Laval Co., Ltd. separation plate type, centrifugal effect 7300).
The white clay was separated and collected at 0 L / hr, and the number of white clay particles in the obtained fat was measured with a fine particle counter (Kurabo Co., product name: KP-100).

As Comparative Examples 1, 2, and 3, a mixed solution of oil and fat and white clay after the decolorizing and refining treatment with the same oil type as in Examples 1 to 3 was treated with a filter press in the usual process and sampled at the outlet of the filter press. The numbers of clay particles in the fats and oils were compared. The results are shown in Table 1.

[0024]

[Table 1] (Examples 4 and 5, Comparative Examples 1 to 6) The decolorizing ability of the used white clay separated and collected by the centrifuge was confirmed. For pig fat (Example 4) and cottonseed oil (Example 5), the white clay obtained by centrifugation was added to the fat and oil at 0.5 and 0.8% by weight, respectively.
Add and stir the butter fat 95 ℃, cottonseed oil 105 ℃, 20 minutes,
After decolorization and filtration, the same amount of new activated clay was added again to perform regular decolorization.

As a comparative example, 0.5, 1.0, and 1.5% by weight of fresh activated clay was added to the same lard (Comparative Example 1,
2, 3), and 0.8, 1.0, 1.6% by weight of cottonseed oil (Comparative Examples 4, 5, 6) with lard 95 ° C., cottonseed oil 1
The mixture was stirred at 05 ° C. for 20 minutes to perform decolorization treatment. The color tone was measured using a Robibond colorimeter. The results are shown in Table 2.

[0026]

[Table 2] From these results, the white clay reduction rate was calculated according to the following formula: 50% lard, 43% cottonseed oil. (Equation) White clay reduction rate = (amount of white clay equivalent to processed oil color in conventional method-amount of white clay equivalent to processed oil in reuse method) / amount of white clay equivalent to processed oil color in conventional method x 100%

[0027]

Industrial Applicability According to the present invention, conventional industrial waste is incinerated alone or mixed with other wastes for incineration, and then discarded as ash, or in the state where oils and fats are adhered, or degreasing. The inorganic adsorbent, which had been disposed of by landfilling, is separated by centrifugal separation as efficiently as a filter, and can be reused in the form of a slurry to simplify the process and improve operability and safety. An excellent low cost process can be realized. Furthermore, the amount of white clay used is 4
By reducing it by 0% or more, it is possible to reduce the generation amount of waste white clay, which is an industrial waste, and reduce the loss of fats and oils adhering to the waste white clay, and the merit effect including these is great.

Claims (5)

[Claims] 1. A method for separating and recovering fats and oils and inorganic adsorbents, which comprises centrifuging a mixed liquid of fats and oils and inorganic adsorbents after the decolorization purification treatment. 2. The method for separating and recovering oil and fat and the inorganic adsorbent according to claim 1, wherein the mixed solution of the oil and fat and the inorganic adsorbent after the decolorization purification treatment is continuously centrifuged. 3. A centrifugal effect of 6000 to 12000, and 100 to a mixed solution of oil and fat and an inorganic adsorbent after the decolorization purification treatment.
The method for separating and recovering fats and oils and inorganic adsorbent according to claim 2, wherein continuous centrifugation is performed at 0 to 6000 L / hr. 4. The oil and fat and the inorganic adsorbent according to claim 1, wherein the temperature of the mixed liquid of the oil and fat and the inorganic adsorbent after the decolorization purification treatment is 60 to 90 ° C. Separation and collection method. 5. The method for separating and recovering fats and oils and inorganic adsorbent according to claim 1, wherein the inorganic adsorbent is activated clay.