JP5058934B2 - Method for regenerating waste cooking oil and cutting oil obtained thereby - Google Patents

Description

  The present invention relates to a method for regenerating waste edible oil, particularly used tempura oil, and cutting oil using the obtained regenerated oil.

Used cooking oils used for tempura etc. are generated from processing factories in restaurants, restaurants, general households, etc., and the amount increases year by year, making disposal difficult. If this waste cooking oil is buried in the soil or poured into sewage, it will cause environmental problems that pollute the hydrosphere.
As a method of disposing of waste cooking oil, a method of absorbing and discarding paper waste materials etc. in a processed oil absorbent material, a method of adding a polymer gelling agent to solidify and disposing it with garbage, etc. are generally performed . However, in the case of mass treatment, there are inconveniences such as absorbed oil oozing out and once solidified, it liquefies and flows out.
In addition, edible oils (especially tempura oil) such as soybean oil, corn oil, sesame oil, safflower oil, olive oil and the like, which are esters of fatty acids and glycerin, are notable as an energy source after being used because they do not contain sulfur.

And after removing impurities from waste edible oil, contact the waste edible oil and water, remove water-soluble substances contained in the oil, and subsequently oxidize activated by containing ozone, oxygen or air to make fuel A method (for example, see Patent Document 1), or a method for producing a fuel containing a fatty acid ester by reacting waste edible oil and alcohol in the presence of a solid catalyst of calcium hydroxide or calcium oxide (for example, see Patent Document 2). Etc. have been proposed.
However, the cost and the means to achieve its desired reference value have not yet been solved, so it appears that it cannot be substituted as part of a mineral oil-based fuel.

Although other methods of recycling and reusing as edible oil have been proposed, it is difficult to process, and the apparatus has not been established for direct combustion treatment, and there is no way for reuse after use. However, environmental protection organizations are working on soap production in detail, and the development of reuse and recycling is awaited.
In addition, various cutting oils such as mineral oils, animal and vegetable oils, and synthetic oils such as silicone are currently used mainly for cutting, cutting, and machining of metal materials. There are mineral oil-based cutting oils mixed with fatty oils or sulfur oils, sulfurized fatty oils, etc., but there are cases where strange odors may be generated due to heat generated during use, and those that produce chlorine-based gases is there. Synthetic oils are expensive and are only used for precision cutting.

JP 2000-119865 A JP 2001-271090 A

Waste cooking oil contains fatty oils and their polymers that are oxidatively modified by cooking and heating as solids or solubles in the main fatty oils, as well as carbohydrates from vegetable ingredients, fats from meat, Proteins, their carbides, and a substantial amount of moisture are dispersed and contained. In addition, iron oxide and waste from the reaction of iron in containers such as oil cans and oxides in waste edible oil when stored and carried in edible oil sources at factories and households are also mixed as impurities. Therefore, it has been difficult to find the processing means and practical use.
The present invention is a method for easily treating and recycling waste edible oil containing miscellaneous impurities such as tempura oil that has been discarded and is difficult to dispose of, and the recycled oil obtained thereby as useful cutting oil, etc. It is intended for reuse.

As a result of diligent research in view of the above problems, the present inventors have found that the waste edible oil is first purified to be a clean waste edible oil, followed by esterification and further refining, based on this finding. It came to make this invention.
That is, the present invention
(1) A filtration step of filtering waste edible oil to remove foreign matters, a specific gravity separation step of heating to 40 to 80 ° C. to perform a specific gravity separation treatment to make a clean waste edible oil, and the clean waste edible oil Esterification by adding 10-15 parts by weight of methanol (concentration 99.9%) and 0.5-1.5 parts by weight of caustic alkali (concentration 95.5%) to 100 parts by weight of clean waste cooking oil An esterification step in which the reaction solution is esterified in the esterification step, and a water washing step in which warm water of 40 ° C to 60 ° C of 1/3 to 2/3 volume of the reaction solution is added and stirred and washed with water , A standing step for standing after the water washing step, an oil / water separation step for removing the water phase portion from the lower layer portion after the standing step to obtain an oil phase liquid, and mixing the warm water with the oil phase liquid. Send air while stirring at 80 ℃ to 80 ℃ An aeration process for removing the water phase by separating oil and water after the aeration process, and at least one adsorbent selected from zeolite, activated clay or starch into an oil phase liquid from which the aqueous phase has been removed. in addition the method of reproducing the waste edible oil, characterized by chromatic and adsorption treatment step of stirring and mixing to adsorb the water and unreacted materials or the like,
(2) Cutting oil using reclaimed oil obtained by the method described in (1) above,
(3) Polishing oil, penetrating oil using regenerated oil obtained by the method described in (1) above,
(4) Diesel engine oil using regenerated oil obtained by the method described in (1) above,
(5) A heat retaining oil using the regenerated oil obtained by the method described in (1) above, and
(6) Liquid cleaning liquid for oil removal using regenerated oil obtained by the method of (1) above,
Is to provide.

The regeneration method of the present invention can perform discarded cooking oil, which has been difficult to dispose of, in a short time by a very simple processing operation, and does not require a complicated device for its implementation, and does not require a large amount of power. Can be processed economically with relatively small equipment.
The obtained reclaimed oil can be used as it is, or by adding some additives, it can be used for cutting and polishing cutting materials and polishing oils such as metals and inorganic materials as well as polymer materials. Moreover, it is effective not only as cutting oil and polishing oil but also as permeation oil, heat retaining oil, diesel engine oil, and liquid cleaning oil.

A preferred embodiment of the method for regenerating waste edible oil of the present invention will be described in detail with reference to the drawings.
Used waste cooking oil from a general household or restaurant industry factory is collected and stored in a waste oil tank (1). The collected edible oil is filtered (2) through a metal screen or coarse filter cloth of about 80 to 100 mesh to remove solid impurities such as tempura koji and dust mixed during accumulation. This waste edible oil is black and thick and thick, so if necessary, heat it to about 40 ° C to 80 ° C, perform specific gravity separation (3), and oxidize during use that could not be removed by filtration. In addition, it is preferable to exclude substances that may inhibit the esterification reaction in the next step, which has been polymerized. The waste edible oil obtained by this purification is hereinafter referred to as clean waste edible oil.

  Clean waste edible oil obtained by purification is put into a reaction vessel equipped with a stirrer, and in the presence of methanol and caustic alkali (for example, potassium hydroxide may be used, but sodium hydroxide may be used) Esterification (4) is carried out at 80 ° C., preferably 40 ° C. to 65 ° C. with slow stirring for a predetermined time. At this time, the transesterification (a) and side reaction saponification (b) and neutralization reaction (c) of free fatty acids mainly occur as follows. The amount of methanol and caustic to be added is 10 to 15 parts by mass of methanol (concentration 99.9%), caustic alkali (concentration 95.5%) 0.5 to 1.5 with respect to 100 parts by mass of clean waste cooking oil. Part by mass is preferred.

C ₃ H ₅ (OCOR) ₃ + 3CH ₃ OH → 3CH ₃ OOCR + C ₃ H ₅ (OH) ₃ (a)
C ₃ H ₅ (OCOR) ₃ + 3KOH → C ₃ H ₅ (OH) ₃ + 3RCOOK (b)
RCOOH + KOH → RCOOK + H ₂ O (c)

  When the reaction is complete, transfer the entire amount of the reaction product from the reaction vessel into the separation vessel and add about 1/3 to 2/3 volume, preferably about 1/2 volume of warm water of 40 ° C. to 60 ° C. of the reaction solution. After stirring and washing with water (5), the mixture is allowed to stand (6) for 30 to 45 minutes. Since it is separated into two layers, the lower layer portion is extracted from the container and removed. Since the lower layer portion contains lard, glycerin, soap generated by side reaction, unreacted material, etc., this is treated to be used separately as described later.

Hot water is mixed with the separated upper layer liquid, heated to 30 ° C to 80 ° C, air is sent in with stirring, deaeration and deodorization is performed by aeration (7), oil / water separation is performed after resting, and the aqueous phase is removed. .
Since this oil phase liquid contains unreacted substances such as water and excess methanol that could not be separated, subsequently, one or more adsorbents selected from zeolite, activated clay or starch are added to this liquid, The mixture is stirred and mixed in a container to adsorb water, unreacted substances, and the like, and an adsorption (8) treatment is performed to separate the reactants mainly composed of higher fatty acid methyl esters. As the adsorbent, zeolite and activated clay are effective, but starch is also preferable from an economical point of view because it exhibits sufficient adsorbability.
The regenerated oil is obtained by transferring the above stirring mixture into a filter paper bag or a filter cloth bag and slowly applying pressure to squeeze out the liquid (filtering treatment (9)).

  The obtained reclaimed oil has a high viscosity and a high boiling point, and its hue is amber and beautiful in appearance. If necessary, a known additive such as an oil improver, an antifoaming agent, an antioxidant, a cleaning dispersant and the like is added, and this is suitable for use as a cutting oil. When this reclaimed oil is used in the cutting process of metals, inorganic materials, hard polymer materials, etc., the components in the oil are less likely to decompose due to the occurrence of high temperature, or an unpleasant odor will occur. The workability is extremely good. In addition, the reclaimed oil can be used not only alone but also mixed with conventionally used cutting oil.

This recycled oil can also be used as a polishing oil. In addition, since it has excellent permeability to narrow gaps and the like, it is also useful as a penetrating oil for processing such as rusted screws and peeling, and is also suitable as a heat retaining oil for heating and heat exchange. Furthermore, since regenerated oil mainly composed of higher fatty acid methyl ester has a high viscosity, it can be used as a diesel engine oil. It is also effective when used as an oil cleaning agent suitable for oil removal.
Moreover, the lower layer part isolate | separated by the above-mentioned stationary (6) process is washed with water (10), and is utilized separately.

Next, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.
Example 1
The waste edible oil collected in the waste edible oil tank 1 was passed through a 100 mesh metal screen to remove solid impurities such as tempura koji and food waste. Subsequently, it heated to about 45 degreeC, it was made easy to flow, the specific gravity separation process was performed, and the clean waste cooking oil was obtained. 400 liters of this clean waste cooking oil was put into a stainless steel reaction vessel (capacity 0.8 m3) equipped with a heater and a stirrer and kept at 50 ° C.
On the other hand, a 10% potassium hydroxide / methanol solution prepared by dissolving potassium hydroxide in methanol (concentration 99.9%) was prepared, and 50 liters of this potassium hydroxide / methanol solution was added to clean waste cooking oil. In addition to the vessel, the reaction solution was kept at about 60 ° C. and slowly stirred for 30 minutes.

The reaction product of which reaction was completed was taken out from the reaction vessel into a separation vessel, 1/2 volume of 50 ° C. warm water of the reaction solution was added, stirred for 5 minutes, and then allowed to stand for 40 minutes. Since it separated into two layers, the lower layer part containing a deposit was extracted and the lower layer part was separately processed.
Warm water was added to the upper layer liquid mainly composed of the higher fatty acid methyl ester remaining after separation, and the mixture was heated to about 40 ° C., and aerated at 40 ° C. with stirring for 12 hours. After aeration, oil-water separation was performed to remove the aqueous phase portion.
Subsequently, 4 kg of activated clay was added to the oil phase liquid, and the mixture was stirred and mixed to adsorb water, unreacted methanol, and the like. The mixture was transferred to a filter cloth bag and slowly pressurized to squeeze out the liquid, yielding 360 liters of regenerated oil that was amber.
The obtained reclaimed oil was composed mainly of fatty acid methyl esters having a flash point of 178 ° C. and ISO viscosity grades of 22 to 46.

Commercially available surfactants, antioxidants, and antifoaming agents were added to 200 liters of the obtained reclaimed oil and used as cutting oil for cutting, cutting, and perforating various metal materials. Commercially available cutting oil used so far (for example, manufactured by Fuso Seiki Co., Ltd., trade name: Magic Cut AM-50, manufactured by Nikko Sangyo Co., Ltd., trade name: RIS CUTSY-55, manufactured by Ciel, Compared with product name: Speed SC-8), oxidation / deterioration was somewhat faster, but it was excellent in terms of machinability, finished surface, damage to the blade, and the like. In addition, the workability was good without feeling bad smell such as smell of smell and chlorine during use.
Similarly, it was excellent when used as a polishing oil or a penetrating oil.

  Moreover, antioxidant, a rust inhibitor, and a cleaning dispersant were added to the obtained reclaimed oil, and it was subjected to an engine test as a diesel engine oil. This engine oil has a lubricating film, good permeability, and a viscosity equivalent to that of a well-known engine oil, so it was inferior to commercially available engine oil.

  Furthermore, the obtained regenerated oil was used as a heat retaining oil. Compared to commercially available coolant fluids and mineral oil-based heat retaining oils, the temperature rises quickly during warming, and the heat retaining properties are excellent by about 20 to 30%. Adjust the amount of glycerin added to the reclaimed oil. Therefore, it was possible to adjust the temperature of heat insulation.

It is a processing-process figure of this invention.

Claims (6)

A filtration step for filtering waste edible oil to remove foreign matters, a specific gravity separation step for heating to 40 to 80 ° C. to carry out a specific gravity separation treatment to make a clean waste edible oil, and the clean waste edible oil the oil 100 parts by weight of 10 to 15 parts by weight of methanol (concentration 99.9%) and 0 · 5 to 1.5 parts by weight caustic ester performing esterification by adding (concentration 95.5%) of A water washing step of adding 1/3 to 2/3 volume of warm water of 40 ° C. to 60 ° C. to the reaction solution esterified in the esterification step, stirring and washing, and the water washing a standing step of standing after the step, the static and the oil-water separation to obtain an oil phase liquid置工after enough to remove the aqueous phase portion from the lower portion, by mixing hot water into the oil phase liquid 30 ° C. to 80 Warm up to ℃ and feed air with stirring A step of separating the water phase by performing oil-water separation after the aeration step, and adding one or more adsorbents selected from zeolite, activated clay or starch to the oil phase liquid from which the water phase portion has been removed. the method of regeneration waste cooking oil, characterized by chromatic and adsorption treatment step of stirring and mixing to adsorb water and unreacted substances Te.   Cutting oil using the regenerated oil obtained by the method according to claim 1.   A polishing oil and a penetrating oil using the regenerated oil obtained by the method according to claim 1.   The diesel engine oil using the regenerated oil obtained by the method of Claim 1.   A heat retaining oil using regenerated oil obtained by the method according to claim 1.   A liquid cleaning liquid for oil removal using the regenerated oil obtained by the method according to claim 1.