JP2010270192A - Method for regenerating edible oil and filter device thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for regenerating edible oil that enhances adsorption efficiency of impurities and also quickly recovers the impurities after adsorption by previously separating (decomposing) the impurities in the oil. <P>SOLUTION: The method for regenerating edible oil comprises: a neutralization and decomposition process that reduces an acid value of the edible oil toward the direction of neutralization by spraying weak alkaline water to the used edible oil which is heated to the temperature of 100°C or higher and also separating the impurities in the oil by evaporation of the weak alkaline water and hydrolysis; an adsorption process that adsorbs the impurities by adding an adsorbent into the edible oil after the neutralization and decomposition process and stirring the same; and a filtration process that recovers the impurities as well as the adsorbent from the edible oil after the adsorption process. In the filtration process, the supernatant edible oil is passed through a filter while the adsorbent is precipitated. In the filtration process, the supernatant is removed to the filter side from one end of a siphon whose another end is equipped with a float. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for regenerating edible oil used as oil for tempura, fries and the like, and a filter for edible oil used in the regenerating method.

  When edible oil is used as deep-fried oil such as tempura and fries, oil and fat are hydrolyzed by heat and moisture contained in the deep-fried seeds to produce free fatty acids, and these free fatty acids are thermally oxidized to produce peroxides, etc. However, it is widely known that edible oil deteriorates (sour). In this way, the cooking oil (old oil) deteriorated by the use of deep-fried food loses its flavor, gives off a strange odor, and the color is not only dark brown to dark brown, but also increases in viscosity. However, simply removing the fried residue during cooking or after cooking makes it unusable for several times of fried cooking.

  Here, there are acid value (AV) and peroxide value (POV) as main indicators of the degree of deterioration of fats and oils. For example, the national guidelines for food vendors who are cooking fried foods, According to the “hygiene norm”, all of the acid values exceeding 2.5 may be replaced with new fats and oils. However, if all of the deteriorated edible oil, such as exceeding the above standards, is disposed of, this is contrary to the recent trend of effective use of resources and preservation of the global environment.

  Therefore, many attempts have been proposed to filter and regenerate edible oil after cooking deep-fried food as means for substantially extending the period of use by suppressing the progress of deterioration of edible oil. Typical examples of the filter include a filter using a fiber filter and an adsorbent such as silica (silicon dioxide) or activated clay. In fact, if a mixture of alkali components such as magnesium oxide in silica or the like is added to edible oil, impurities in the oil are removed by its adsorption action, and effects such as decolorization and reduction in acid value have been confirmed. . Here, in addition to the above-mentioned silica and activated clay, activated carbon, zeolite, and the like are employed as the adsorbent, and attempts have been made to combine three or more adsorbents in order to further enhance the purification effect (for example, patent documents). 1).

JP 2005-231309 A

  The fiber filter and the adsorbent described above are the same in that contaminants in the oil adhere to the tissue and are removed. The fiber filter is installed directly on the fryer, so that edible oil can be naturally used by using the oil outlet. Although there is an advantage that it can be filtered, the removal rate of impurities is poor because it is coarser than the adsorbent. On the other hand, the adsorbent has a large specific surface area due to its porosity, so the removal rate of impurities is high. In particular, the adsorbent is powdered, directly put into edible oil, and stirred, The opportunity for contact with foreign substances increases, and the removal rate can be further increased.

  However, an adsorbent obtained by pulverizing silica or activated clay precipitates in a close-packed state if left to stand, and forms a precipitated layer like water-soluble starch powder on the oil bottom. Therefore, if the powdered adsorbent is directly put into a fryer or a circulating filter connected thereto, the oil outlet is clogged. This is the same when a fiber filter is installed at the oil discharge port. For this reason, when using a powdery adsorbent, transfer the used cooking oil from the fryer to another container once, perform the adsorption treatment in this separate container, and then wait until the adsorbent is completely precipitated. Thus, it takes time to draw only the supernatant cooking oil and return it to the fryer. Moreover, since the said another container is utilized next time, after returning supernatant cooking oil to a fryer, there also exists the effort which removes the adsorbent which precipitated from the said another container.

  In this regard, Patent Document 1 describes that a powdery adsorbent is packed into a bag made of nonwoven fabric to form a cartridge. In this case, the adsorbent (cartridge) after treatment can be easily removed. However, since the adsorbent cannot be diffused into the oil, the removal rate of impurities increased by making the powder is sacrificed. Further, if the cartridge is left in the oil, the powdery adsorbent is compacted in the bag, so that the edible oil cannot be naturally filtered using the oil drain port as in the fiber filter.

  The present invention has been made in view of the above-described conventional problems. The object of the present invention is to improve the adsorption efficiency of the impurities by separating (decomposing) the impurities in the oil in advance. An object of the present invention is to provide a method for regenerating edible oil that can quickly recover impurities later and a filtration device for the same.

  In order to achieve the above object, in the present invention, a neutralization and decomposition process in which a weak alkaline substance is added to used cooking oil heated to an oil temperature of 100 ° C. or more to reduce the acid value of the cooking oil in the neutralization direction. And an adsorption step of adsorbing and stirring the adsorbent into the edible oil after the neutralization decomposition treatment, and a filtration step of collecting the impurity together with the adsorbent from the edible oil after the adsorption treatment Thus, the filtration step used means for passing the supernatant cooking oil through the filtration filter in a state where the adsorbent was precipitated. Specific examples of charging the weak alkaline substance in the neutralization decomposition step include a method of spraying weak alkaline water and a method of previously adjusting the adsorbent in the adsorption step to weak alkalinity and charging it. In addition, the acquisition method of the adsorption agent adjusted to weak alkalinity has sprayed weak alkaline water on cellulose, for example, and dried this.

  According to the means, first, the oxidation value was increased by repeated fried food use by spraying weak alkaline water directly on a relatively high temperature edible oil or by introducing an adsorbent adjusted to weak alkalinity. The edible oil is reduced in the neutralization direction and impurities in the oil are separated, so that the subsequent adsorption process is promoted. The pH of the alkaline substance is scheduled to be 7.5 to 10.5, but is not limited to this range. In the adsorption step, the adsorbent basically adsorbs the separated impurities and the like, but by using a weak alkaline adsorbent, the edible oil can be neutralized and reduced in the adsorption step. In addition, in order to reuse the edible oil after the adsorption treatment, it is necessary to remove the adsorbent from the edible oil, but in the present invention, the adsorbent is precipitated and only the supernatant is filtered. The agent can be completely removed, and a regenerated edible oil with high purity can be obtained. In this filtration step, it is a matter of course that in addition to the adsorbent, various impurities (contaminants) that could not be adsorbed by the oil residue or adsorbent can be filtered.

  The adsorbent acts to adsorb impurities in the oil, and the specific composition is preferably a mixture of two or more powdered adsorbents containing cellulose as an essential component. In this case, at the time of mixing, the cellulose powder can be combined with another adsorbent by its electrostatic attraction, thereby making it possible to form a filter medium that is not easily scattered in the air. Examples of other adsorbents include silica, (active) clay, activated carbon, diatomaceous earth, zeolite, and the like. One selected from these, or a mixture of two or more selected may be adopted. However, other components may be employed as long as they do not have a sanitary effect on the human body and can adsorb impurities in the oil by being introduced into edible oil. Moreover, the method of carrying out the adsorption process with the adsorbent which mixed alkali components, such as magnesium oxide, simultaneously is also contained in this invention.

  In the present invention, the filtration step uses a means of transferring the supernatant from the other end of the siphon provided with a float at one end to the filtration filter side. In this means, the siphon sucks the edible oil supernatant near the oil level while the one end provided with the float descends in conjunction with the oil level as the edible oil suction port, and drains the oil from the other end. Thus, according to the means, after the adsorbent is precipitated, the edible oil can be simply allowed to stand, and only the supernatant can be transferred to the filtration filter by siphon in a completely stationary state. Note that the siphon is to transfer the liquid using the differential pressure at both ends, and is also used in the meaning of the present invention.In the present invention, the other end is always fixed at a lower position than the one end. Since the position of one end is displaced in conjunction with the oil level as described above, it does not necessarily indicate only a downward U-shaped siphon.

  Further, in the present invention, the filtration filter uses a means in which at least a filter paper as an upper filter capable of supplementing the adsorbent and a filter medium as a lower filter with a finer mesh than this are arranged in order. Since the adsorbent is almost removed from the edible oil at this time, the adsorbent and impurities can be completely removed by two-stage filtration of the filter paper and the filter medium.

  Here, it is preferable that the filter medium is obtained by molding fibrous or powdery cellulose, fibrous pulp, or a mixture of the cellulose and the pulp into a solid form. This is because cellulose fibers and the like realize a high adsorption rate, and are easy to handle such as being charged and collected after use by being molded into a solid form.

  By the way, in the regeneration method of the used cooking oil mentioned above, the neutralization decomposition process by spraying weak alkaline water can be performed on a frying pan or a fryer. However, since oil splash occurs during spraying, it is preferable to provide a protective fence on the top of the frying pan or fryer. The adsorption step can be performed in a container that can receive high-temperature oil from a fryer or the like. The container can be simply used as it is, which was originally filled with cooking oil. On the other hand, as a filtration device used in the filtration step, in the present invention, a supernatant recovery container in which the other end of the siphon is connected to the bottom oil discharge port, and a filter medium is disposed in the opening of the container having the bottom opened, and the inside of the container It was decided to use a filter container with a filter paper. Any container can be used by processing the above-mentioned Ito can most simply.

  Further, in the apparatus, the filter paper is arranged on the upper part of the legged net that is detachably installed in the filter container. As a result, a gap corresponding to the length of the leg is formed between the filter container and the filter paper, so that the filtration rate is much faster than when the filter paper is in close contact with the filter container inner wall. Furthermore, the filter paper can be easily attached to the filter container, and the filter paper after the filter can be removed together with the net, so that the hands are not soiled. Note that the net portion of the legged net can be constituted by a flat net or a net cage raised around the net.

  According to the regeneration method of the present invention, first, the edible oil is reduced in the neutralization direction by a simple method of adding a weak alkaline substance to the used edible oil in the neutralization decomposition step. The causative impurities can be removed by adsorption, and decolorization, odor reduction, and acid value promotion can be suppressed. As a result, the life of edible oil can be extended. Moreover, in the present invention, a high-purity regenerated edible oil from which the adsorbent and impurities are completely removed can be obtained by filtering the supernatant on which the adsorbent has been precipitated. In particular, since the supernatant is transferred to the filtration process by a siphon, the user only has to leave the edible oil after the adsorption process, and there is no trouble of pumping the supernatant or sucking it up with a pump as in the past. Furthermore, since the filtration filter has a double structure of filter paper and filter medium, the adsorbent and the like can be completely removed more reliably. Furthermore, as the filter medium, cellulose or pulp in the form of a fiber or a mixture of these is molded into a solid form, so that it is easy to handle while obtaining a high adsorption capacity with cellulose. I was able to.

  Further, the filtration device used in the method of the present invention includes a supernatant collection container in which the other end of the siphon is connected to the bottom oil discharge port, a filter paper disposed inside the bottom opening container, and a filter medium disposed in the bottom opening. Since these containers themselves can be obtained by processing openings or the like for draining oil into empty containers, the structure can be very simple. Moreover, since the filter paper is placed in the upper part of the net with legs, it is put into the filter container, so that the filtration speed is fast, and even if a large sheet is used as the filter paper, it can be easily set in the filter container, Further, the filter paper can be prevented from being lifted during the filtration, and the filter paper can be collected together with the net after the filtration.

Flow chart of the present invention Conceptual diagram of the configuration that realizes the neutralization decomposition process and the adsorption process Conceptual diagram of a filtration device that realizes the filtration process Sectional view of the supernatant collection container in the filtration device Sectional view of the filtration container in the filtration device

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. FIG. 1 is a flowchart showing the method of the present invention in the order of steps. First, as a preparation step, the cooking oil to be regenerated is heated to 100 ° C. or higher. This is because impurities (such as peroxides) in the oil are separated in the next neutralization decomposition step. However, it is also possible to target edible oil that is in a high-temperature state after the end of cooking without raising the temperature. In addition, although the target value of temperature rise is not specifically limited, It is preferable to set to normal frying temperature (160-180 degreeC). And in a neutralization decomposition process, while weakly alkaline water is sprayed to the edible oil heated up, while reducing an edible oil in the neutralization direction, the impurity in oil is isolate | separated. Thus, the next adsorption process is efficiently performed by separating the impurities in advance. It has been confirmed from the experience of the present inventors that when a weak alkaline water is sprayed on a relatively high temperature edible oil, an evaporation phenomenon similar to a small steam explosion occurs, and impurities are separated by hydrolysis of the edible oil. Yes. However, in this neutralization decomposition step, if an alkaline substance that neutralizes and reduces edible oil having a high oxidation value is introduced, the adsorbent used in the subsequent adsorption step is weakened in advance instead of spraying weak alkaline water. It is possible to adjust the adsorbent to edible oil after adjusting to alkalinity. Next, in the adsorption step, the adsorbent is put into the edible oil after the neutralization decomposition treatment, and the impurities separated in the previous step are adsorbed on the adsorbent by stirring. At this time, the oil temperature and the material and input amount of the adsorbent can be changed according to the degree of deterioration of the edible oil. As a standard, 1 to 10 wt% of an adsorbent (powder) obtained by mixing silica, cellulose, or the like is added to an edible oil having an oil temperature of 150 ° C. and an acid value of 0.5. In the final filtration step, the adsorbent and impurities still remaining and floating in the oil are collected. Specifically, it can be realized by applying the edible oil after the adsorption treatment to a filtration filter. The filtration filter may be any filter as long as it can supplement at least the adsorbent, but preferably has a double filtration structure in which the filter paper is an upper filter and the lower filter is a cellulose filter medium. Regenerated edible oil is obtained in this filtration step, and the final storage step shown in FIG. 1 is not an essential requirement of the present invention, but it is difficult to oxidize by storing the filtered regenerated edible oil back in the fryer. This has been confirmed from the experience of the present inventors.

  Subsequently, a specific configuration of an apparatus or the like for realizing each process will be described. FIG. 2 shows a configuration example for realizing the neutralization decomposition step and the adsorption step, in which 1 is a fryer, and 2 is a receiving container for temporarily storing edible oil dropped from the fryer 1. Reference numeral 3 denotes a sprayer such as a spray bottle containing weak alkaline water. That is, the neutralization decomposition process is completed by spraying weak alkaline water directly on the receiving container 2 using the sprayer 3 with respect to the high temperature cooking oil heated by the fryer 1. For home use, the fryer 1 corresponds to a cooking utensil such as a frying pan for frying. Thus, the neutralization decomposition process of this invention is realizable only by spraying weak alkaline water with the sprayer 3 prepared separately using the conventional instrument as it is. However, in this neutralization decomposition step, instead of spraying weakly alkaline water, the adsorbent adjusted to be weakly alkaline as described above may be charged. Do.

  Further, the adsorption step after the neutralization and decomposition treatment can be realized simply by transferring edible oil from the fryer 1 to an appropriate receiving container 2 and charging and stirring the adsorbent in the receiving container 2. The receiving container 2 only needs to have durability against the heat of edible oil, and most easily, a canister that originally contained edible oil can be used.

  FIG. 3 shows a configuration example for realizing the filtration step, in which 4 is a supernatant collection container and 5 is a filtration container. In this filtration step, the edible oil that has been subjected to the adsorption treatment is transferred from the container 2 to the supernatant collection container 4. At this time, after the adsorbent is stirred, the receiving container 2 is left to stand for a while, It is preferable to transfer the edible oil after precipitation. This is because the filtration step can be efficiently performed by reducing the transfer amount to the supernatant collection container 4 as much as possible. In this way, the edible oil transferred from the receiving container 2 is first filtered into the container 5 while precipitating the adsorbent in the supernatant collection container 4, and further into the filtration container 5. After the remaining adsorbent and impurities are filtered off, the regenerated edible oil is returned to the fryer 1.

  Here, in the case of the present embodiment, as shown in FIG. 3, the supernatant collection container 4 and the filtration container 5 are stacked up and down, and further, these are placed on the fryer 1, so that from the filtration process to the storage process. The user is not forced to do any work, and the process is realized almost automatically.

  That is, as shown in FIG. 4, the supernatant collection container 4 has a structure in which the lower end 4d of the tube 4c is directly connected to the bottom oil discharge port 4b of the container body 4a and the float 4f is provided on the upper end 4e of the tube 4c. . In addition, 4g is a hook which hooks the upper end of the tube 4c on the upper edge of the side wall of the container body 4a and temporarily fixes it when not in use. According to this configuration, the edible oil transferred from the receiving container 2 to the container body 4a by the differential pressure between the upper end 4e and the lower end 4d of the tube 4c, that is, siphon action, is always located near the oil surface by the float 4f. Only the supernatant is sucked from the opening of the upper end 4e, and the supernatant can be transferred from the bottom oil discharge port 4b to the container 5 via the lower end 4d. Moreover, the tube 4 is made of a flexible material, and the upper end 4e is immersed in the oil by the float 4f, and the tube 4 is lowered in conjunction with the oil surface. Is possible. In addition, the container main body 4a can be obtained by processing the Ito can as the simplest configuration, similarly to the receiving container 2.

  On the other hand, as shown in FIG. 5, the filter container 5 has a large number of through holes 5b formed on the bottom surface of the container body 5a, on which the cellulose filter medium 5c is placed, and a filter paper 5d is mounted therein. It has a two-stage filtration configuration with a net cage 5e. The cellulose filter medium 5c is a solid body formed by molding a mixture of cellulose fibers or cellulose powder and pulp into a lump. However, since it floats in oil, in order to prevent the lifting, in this embodiment, a mesh basket with a surrounding mesh is used. The filter medium 5c is pressed by the leg member 5f of 5e. The filter paper 5d is attached to the inner wall of the mesh basket 5e, and a hook 5g is formed on the mesh basket 5e so as to be hooked on the upper edge of the side wall of the container body 5a. By inserting the mesh basket 5e into the container body 5a with the filter paper 5d attached, a gap with the container body 5a is provided around the filter paper 5d. Then, by dropping the supernatant from the supernatant collection container 4 into the container body 5a in which the filter paper 5d and the cellulose filter medium 5c are set in this way, most of the adsorbent and impurities remaining in the supernatant are supplemented by the filter paper 5d, and then After further fine impurities and the like are captured by the cellulose filter medium 5c, regenerated oil is obtained through the through holes 5b.

  The material and basis weight of the filter paper 5d are not particularly limited as long as the adsorbent and the like can be supplemented. If the shape of the filter paper is a bag, it is easiest to attach it to the mesh basket 5e. However, it may be a large and small sheet. Further, the leg member 5f is shown separately from the mesh cage 5e, but both may be integrated, and a flat mesh may be adopted instead of the mesh cage 5e. It is preferable to adopt a bag-shaped bag. Furthermore, the filter medium can be composed of cellulose fibers alone or pulp fibers alone, or can be composed of cellulose powder or cellulose fibers mixed with pulp fibers.

  On the other hand, if the filtration container 5 is a sealed pressure container, the filtration speed can be increased depending on the pressurized state.

  The edible oil regenerated by the present invention can be repeatedly used for deep-fried food cooking, and finally used as fuel. It is very reasonable if it is reused as a fuel in a restaurant, but it can also be used as an alternative fuel for diesel vehicles and the like. Moreover, the filtration filter after a filtration process can also be used for a fertilizer, and can attain high reuse of resources and environmental conservation. Furthermore, the object to be refined can be applied not only to used cooking oil but also to machine oil.

1 Flyer 2 Receiving container 3 Sprayer 4 Supernatant collection container (part of filtration device)
5 Filtration container (part of filtration device)

Claims (9)

A neutralization and decomposition step in which a weak alkaline substance is added to used edible oil heated to an oil temperature of 100 ° C. or higher to reduce the acid value of the edible oil in a neutralizing direction, and the edible oil after the neutralization and decomposition treatment The adsorbent is adsorbed to the adsorbent by adsorbing and stirring the adsorbent, and the filtration step of collecting the impurity together with the adsorbent from the edible oil after the adsorption treatment. A method for regenerating edible oil, wherein the edible oil in the supernatant is passed through a filter in a precipitated state. The method for regenerating edible oil according to claim 1, wherein the neutralization and decomposition step comprises spraying weak alkaline water onto the edible oil as a weak alkaline substance. The method for regenerating edible oil according to claim 1, wherein the neutralizing and decomposing step is a step of adding, into the edible oil, an adsorbent in the adsorption step that has been adjusted to be weakly alkaline in advance as a weak alkaline substance. The method for regenerating edible oil according to claim 1, 2 or 3, wherein the filtration step is one in which the supernatant is transferred to the filtration filter side from the other end of the siphon provided with a float at one end. The edible product according to any one of claims 1 to 4, wherein the filtration filter is formed by sequentially arranging a filter paper as an upper filter capable of supplementing at least an adsorbent and a filter medium as a finer lower filter than the filter paper. How to regenerate oil. 6. The method for regenerating used edible oil according to claim 5, wherein the filter medium is obtained by molding fibrous or powdery cellulose, fibrous pulp, or a mixture thereof into a solid form. A filtration device used in a filtration step in the method for regenerating edible oil according to any one of claims 4 to 6, wherein a supernatant recovery container having a siphon other end connected to a bottom oil discharge port, and a bottom opening An edible oil filtration apparatus comprising a filter container in which a filter paper is arranged inside the container and a filter medium is arranged in the bottom opening. 8. The edible oil filtration device according to claim 7, wherein the filter paper is disposed on an upper part of a legged net that is detachably installed in the filter container. The apparatus for filtering edible oil according to claim 7 or 8, wherein the filtration container constitutes a pressurized container.

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