JPWO2020059885A1 - Glycerin purification method and purification system, release agent manufacturing method and release method - Google Patents

Abstract

A method for purifying glycerin from a raw material containing at least one of glycerin and a fatty acid glycerin ester, the first separation step of mixing the raw material and an inorganic acid to separate the first oil and the first glycerin solution. A second separation step of separating the second oil component and the precipitated inorganic salt from the neutralized glycerin solution and a neutralization step of neutralizing the first glycerin solution with an alkaline substance are provided. A characteristic method for purifying glycerin. According to the present invention, glycerin can be purified from a raw material containing glycerin or a fatty acid glycerin ester at low cost and while suppressing the burden on the environment. The present invention also provides a glycerin purification system, a method for producing a stripper of a composition containing asphalt or cement, and a stripping method.

Description

The present invention relates to a method and system for purifying glycerin, and more particularly to a method and system for purifying glycerin from a raw material containing glycerin or a fatty acid glycerin ester.
The present invention also relates to a method for producing a release agent for a composition containing asphalt or cement, and a method for removing a composition containing asphalt or cement.

In recent years, from the viewpoint of preventing global warming, the development of fuels that can replace conventional fossil fuels by reducing the generation of carbon dioxide and leading to the recycling of resources has been promoted, and one of them is vegetable oil and waste cooking oil. Biodiesel fuels made from such materials are attracting attention. As a method for synthesizing biodiesel fuel, a method of synthesizing biodiesel fuel by transesterification reaction using animal and plant fats and oils and monohydric alcohol as raw materials and an alkaline substance such as potassium hydroxide as a catalyst is the mainstream (for example, Non-Patent Document 1). In this synthetic reaction, a by-product containing glycerin (also referred to as "waste glycerin" in the present specification) is also produced.

When free fatty acids are industrially produced from fats and oils, the production methods include high-temperature and high-pressure decomposition methods and enzymatic decomposition methods, all of which hydrolyze fats and oils derived from animals and plants to release fatty acids. Is what you do. Even in such hydrolysis, a by-product containing glycerin is produced.

Waste containing glycerin contains a large amount of impurities such as catalysts and unreacted fats and oils. Therefore, although glycerin itself has a use as a raw material for pharmaceuticals and cosmetics, the above-mentioned glycerin-containing waste must be purified at a great cost in order to be used as a raw material for pharmaceuticals and cosmetics. , Was not practical. Therefore, glycerin-containing waste was often disposed of as industrial waste.

On the other hand, when fats and oils such as edible oils deteriorate, hydrolysis occurs or carbon chains are broken and further oxidized, resulting in oils having a high acid value (high acid value oils). Further, in the deoxidizing step in the refining of vegetable oils and fats, oil slag is separated from the oils and fats (crude oil). These high acid oils and slags are wastes containing fatty acid glycerin esters.

Journal of Marine Engineering Society of Japan, 2012, Vol. 47, No. 1, pp. 45-50

A first object of the present invention is to provide a method for purifying glycerin from a raw material containing glycerin or a fatty acid glycerin ester at low cost and while suppressing the burden on the environment. Furthermore, a second object of the present invention is to provide a new method of utilizing glycerin purified by the above method.

As a result of diligent research to solve the above problems, the present inventor first mixes a raw material containing at least one of glycerin and a fatty acid glycerin ester with an inorganic acid to efficiently separate the oil and the glycerin solution. It was found that by neutralizing the obtained glycerin solution with an alkaline substance, the remaining oil content can be separated more efficiently.
Furthermore, they have found that the purified glycerin obtained by the above method is suitable as a release agent for a composition containing asphalt or cement, and have completed the present invention.
Specifically, the present invention is as follows.

[1] A method for purifying glycerin from a raw material containing at least one of glycerin and a fatty acid glycerin ester.
The first separation step of mixing the raw material and the inorganic acid to separate the first oil component and the first glycerin solution, and
A neutralization step of neutralizing the first glycerin solution with an alkaline substance, and
A second separation step that separates the second oil and precipitated inorganic salts from the neutralized glycerin solution, and
A method for purifying glycerin, which comprises.
[2] The method for purifying glycerin according to [1], wherein the raw material contains waste glycerin produced as a by-product in the process of producing a biodiesel fuel.
[3] The method for purifying glycerin according to [1] or [2], wherein the raw material contains a high acid value oil having an acid value of 10 mgKOH / g or more.
[4] The method for purifying glycerin according to [1] to [3], wherein the pH of the mixed solution of the raw material and the inorganic acid is 3 or less.
[5] The method for purifying glycerin according to [1] to [4], wherein the inorganic acid is concentrated sulfuric acid.
[6] The method for purifying glycerin according to [1] to [5], wherein in the neutralization step, the pH of the glycerin solution is neutralized to be 4.0 to 7.5.
[7] The method for purifying glycerin according to [1] to [6], wherein the alkaline substance contains waste glycerin and / or oil residue.
[8] The method for purifying glycerin according to [1] to [7], which comprises an alcohol separation step of separating a monohydric alcohol from the glycerin solution obtained in the second separation step.
[9] A method other than the alkali catalyst method, which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method. A second esterification step for producing a fatty acid alkyl ester by one method is provided.
In the second esterification step, the first oil separated in the first separation step and / or the second oil separated in the second separation step is used as a raw material.
The method for purifying glycerin according to [1] to [8].
[10] A system for purifying glycerin from a raw material containing at least one of glycerin and a fatty acid glycerin ester.
A first separation device that mixes the raw material and an inorganic acid to separate the first oil and the first glycerin solution.
A neutralizer that neutralizes the first glycerin solution with an alkaline substance,
A second separator that separates the second oil and precipitated inorganic salts from the neutralized glycerin solution,
A glycerin purification system characterized by comprising.
[11] The glycerin according to [10], further comprising an alcohol separating device for separating a monohydric alcohol from the glycerin solution from which the second oil component and the inorganic salt have been separated. Purification system.
[12] A method for producing a release agent for a composition containing asphalt or cement, which comprises using the purified glycerin obtained by the method according to [8] as an essential component of the release agent.
[13] The method for producing a release agent according to [12], which comprises an oil component removing step of removing a third oil component separated from the refined glycerin.
[14] The method for producing a release agent according to [13], wherein a surfactant having an HLB value of 14 or less is added to the purified glycerin in the oil removal step.
[15] The method for producing a release agent according to [14], wherein the surfactant having an HLB value of 14 or less is a nonionic surfactant.
[16] The method for producing a release agent according to [13] to [15], wherein a nonionic surfactant having an HLB value of 15 or more is added to the glycerin solution from which the third oil component has been separated.
[17] The method for producing a release agent according to [12] to [16], which comprises a dilution step of diluting the purified glycerin.
[18] Containing asphalt or cement, which comprises treating the release agent produced by the method according to [12] to [17] on a surface to which the composition containing the asphalt or cement can come into contact. Method of peeling the composition.

According to the method for purifying glycerin according to the present invention, glycerin can be purified from a raw material containing glycerin or a fatty acid glycerin ester at low cost and while suppressing the burden on the environment.
Further, the release agent according to the present invention and the release method using the release agent are excellent in the release effect of the composition containing asphalt or cement, and the load on the environment is suppressed.

It is a figure which shows the flow of the purification method of glycerin which concerns on one Embodiment of this invention. It is a figure which shows the flow of the 2nd esterification step provided with the preferable embodiment of this invention. It is a figure explaining the purification system of glycerin which concerns on one Embodiment of this invention. It is a figure which shows the flow in a particularly preferable aspect of the manufacturing method of the release agent which concerns on one Embodiment of this invention. It is a photograph showing the result of the asphalt dissolution test.

Hereinafter, embodiments of the present invention will be described.
[Glycerin purification method]
The method for purifying glycerin according to an embodiment of the present invention is a method for purifying glycerin from a raw material containing at least one of glycerin and a fatty acid glycerin ester, in which the raw material and an inorganic acid are mixed and combined with the first oil component. A first separation step for separating the first glycerin solution, a neutralization step for neutralizing the first glycerin solution with an alkaline substance, and a second oil component and precipitated inorganic salts from the neutralized glycerin solution. A second separation step for separating the above is provided.

In the present embodiment, in the first separation step, the oil component and the glycerin solution are efficiently separated by mixing the raw material and the inorganic acid. When the raw material contains a fatty acid glycerin ester, glycerin is produced by a transesterification reaction with a monohydric alcohol or the like and is separated from the oil component.
Then, by neutralizing the obtained glycerin solution, it becomes easy to separate the remaining oil and the precipitated inorganic salt.
According to this embodiment, glycerin can be purified efficiently and inexpensively by a general-purpose method such as addition, neutralization, and separation of an acid. Further, since the oil, the inorganic salt, etc. produced as a by-product in the present embodiment can be reused, the burden on the environment is small.

Hereinafter, the method for purifying glycerin according to the present embodiment will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a flow in a particularly preferable embodiment of the method for purifying glycerin according to the present embodiment. FIG. 1 is illustrated so that the alcohol separation step, which is an optional step, is carried out after the second separation step.

(1) Raw Material The raw material used in the present embodiment is not particularly limited as long as it contains at least one of glycerin and fatty acid glycerin ester.
Examples of the raw material containing glycerin include waste containing glycerin. Further, since the raw material containing the fatty acid glycerin ester produces glycerin by an acid-catalyzed transesterification reaction or the like in the first separation step described later, these can also be preferably used.
Hereinafter, the glycerin-containing waste and the fatty acid glycerin ester-containing composition will be described in some detail.

(1-1) Glycerin-containing waste The glycerin-containing waste that can be used in the present embodiment includes waste glycerin produced as a by-product in the production process of biodiesel fuel, and glycerin waste liquid produced as a by-product in the production process of free fatty acids. Examples thereof include sweet water and washing waste water of fatty acid alkyl esters.

Here, the glycerin waste liquid produced as a by-product in the process of producing free fatty acids is waste produced as a by-product when hydrolyzing fats and oils of animals and plants to produce free fatty acids. Examples of the method for producing free fatty acid by hydrolysis include a high-temperature and high-pressure decomposition method and an enzymatic decomposition method. The glycerin waste liquid produced as a by-product in such a production process includes unreacted fats and oils, partially hydrolyzed fats and oils, and the like, in addition to glycerin.
In addition, sweet water is a by-product in the case of saponifying (alkaline hydrolysis) fats and oils to produce fatty acid salts (for example, in the manufacturing process of soap), and contains glycerin, water, alkali and the like.
Cleaning wastewater of fatty acid alkyl ester is waste water generated when a reactant is washed in the production process of fatty acid alkyl ester such as biodiesel fuel, and is produced as a by-product in the production reaction of fatty acid alkyl ester in addition to water. It contains glycerin, and further contains unreacted free fatty acids and salts thereof, monohydric alcohols and the like.

Next, the waste glycerin produced as a by-product in the manufacturing process of biodiesel fuel will be described in a little more detail.
The fatty acid alkyl ester used as a biodiesel fuel can be obtained by adding a monohydric alcohol such as methanol and an alkali catalyst such as potassium hydroxide to a raw material fat such as vegetable oil and performing a transesterification reaction.

Raw oils and fats for biodiesel fuel include vegetable oils such as rapeseed oil, palm oil, olive oil, sunflower oil, soybean oil, rice oil and cannabis oil; animal fats such as fish oil, pork fat and cow pig; waste cooking oil such as tempura oil; Can be used.
As the monohydric alcohol, methanol, ethanol, 1-propanol, ethylhexanol and the like can be used, and methanol and ethanol are preferable, and methanol is particularly preferable.
Potassium hydroxide, sodium hydroxide, calcium oxide and the like can be used as the alkali catalyst, but potassium hydroxide is used from the viewpoint of precipitation property and ease of reuse of the inorganic salt separated and recovered in the present embodiment. preferable.

In the transesterification reaction, the fatty acid glycerin ester contained in the raw material fat and oil reacts with the monohydric alcohol to produce the fatty acid alkyl ester and glycerin. The obtained reaction solution is separated into a fatty acid alkyl ester phase and a waste glycerin phase, and in the production of biodiesel fuel, the obtained fatty acid alkyl ester phase is recovered and washed to obtain the biodiesel fuel. do.

On the other hand, the waste glycerin phase contains unreacted monohydric alcohol, unreacted fats and oils, fatty acids and salts thereof, alkali catalysts, and impurities derived from raw material fats and oils, in addition to containing glycerin in a high concentration. The waste glycerin may be liquid waste glycerin or solid waste glycerin, but from the viewpoint of workability, handling and the like, liquid waste glycerin is preferable.
The content of glycerin, monohydric alcohol, fats and oils, fatty acids and salts thereof in waste glycerin is not particularly limited, but usually, glycerin is 25% by mass or more and 65% by mass or less, and monohydric alcohol is 2% by mass with respect to the whole waste glycerin. % Or more and 20% by mass or less, and the total amount of fats and oils, fatty acids and salts thereof is often 30% by mass or more and 50% by mass or less. From the viewpoint of making the method for purifying glycerin according to the present embodiment more stable, glycerin is 30% by mass or more and 65% by mass or less, and monohydric alcohol is 3% by mass or more and 15% by mass or more, respectively, with respect to the whole waste glycerin. The total content of fats and oils and fatty acids and salts thereof may be 25% by mass or more and 55% by mass or less.

Since the waste glycerin contains a large amount of an alkaline catalyst, the pH is often 9 or more, and in the present embodiment, it may be 9 to 13.
In the first separation step, the water content in the waste glycerin shall be 5% by mass or less from the viewpoint of facilitating the acid-catalyzed esterification reaction with the unreacted fats and oils contained in the waste glycerin and the monohydric alcohol. Is preferable, and 3% by mass or less is particularly preferable. The water content of the waste glycerin can be appropriately adjusted by heating, reducing the pressure, using a desiccant or the like, or permeating the purified glycerin.

Here, glycerin can be used as a raw material for pharmaceuticals and cosmetics, but in order to use glycerin contained in waste glycerin for such purposes, it is necessary to purify it with high purity, which requires a great deal of cost and energy. Therefore, waste glycerin has a considerably low utility value as glycerin, and has been difficult to process in the past.
On the other hand, according to the present embodiment, since the purity of glycerin obtained is high even when waste glycerin is used as a raw material, an operation of further increasing the purity for applications such as pharmaceuticals and cosmetics (for example, distillation). Etc.) is also easy. Since waste glycerin is inexpensive, it is particularly suitable as a raw material for the present embodiment.

(1-2) Fatty Acid Glycerin Ester-Containing Composition In the present embodiment, a composition containing a fatty acid glycerin ester can also be used as a raw material. In the present embodiment, in order to carry out the first separation step of adding an acid, a composition containing a fatty acid glycerin ester is used, and the yield of glycerin is increased by an acid-catalyzed esterification reaction or the like in the first separation step. Can be done.
Examples of the composition containing the fatty acid glycerin ester include fats and oils containing fatty acid glycerin ester as a main component of waste cooking oil, animal and vegetable oil, high acid value oil (gristrap oil, sewage oil, ground groove oil, waste liquid treated recycled oil, etc.). ; A composition containing a fatty acid salt such as an oil slag or soap as a main component; and the like.
In addition, in this specification, "the main component" means the component having the highest content in the composition (however, when the most abundant component is water, the component having the second highest content). This means that the content is preferably 40% by mass or more, more preferably 50% by mass or more.

High acid value oil refers to fats and oils having an acid value of 10 mgKOH / g or more, and contains free fatty acids and the like in addition to fatty acid glycerin ester which is the main component of fats and oils. The acid value may be 20 mgKOH / g or more, and further may be 50 mgKOH / g or more. The upper limit of the acid value is usually 200 mgKOH / g or less.
Oil slag is a by-product separated from fats and oils (crude oil) in the deoxidizing step in the refining of vegetable fats and oils, and contains fatty acid salts, fatty acid glycerin esters, alkalis, water and the like.

(2) First Separation Step In the first separation step, a raw material containing at least one of glycerin and a fatty acid glycerin ester is mixed with an inorganic acid, and the first oil and the first glycerin solution are phase-separated. It is a process to do.
The oil content separated in this step includes fatty acid glycerin ester and free fatty acid in addition to fatty acid alkyl ester.

When a raw material containing glycerin is used, particularly when waste glycerin is used, in this step, the salt of the fatty acid contained in the waste glycerin is converted into a free fatty acid by an inorganic acid. Further, the fatty acid and its salt use an inorganic acid as an acid catalyst and produce a fatty acid alkyl ester by an esterification reaction with an unreacted monohydric alcohol contained in waste glycerin.

When a fatty acid glycerin ester-containing composition is used as a raw material, a fatty acid alkyl ester and glycerin are produced by a transesterification reaction with a monohydric alcohol. The monohydric alcohol in this case can be added separately, and for example, the monohydric alcohol recovered in the alcohol separation step described later can be used. Further, the unreacted monohydric alcohol contained in the waste glycerin may be utilized by treating the waste glycerin at the same time as the fatty acid glycerin ester-containing composition.
When the first separation step is performed in the presence of a monohydric alcohol, this step can also be referred to as an acid-catalyzed esterification step. In comparison with the second esterification reaction described later, the first separation step may be referred to as "first esterification step".

Even when the monohydric alcohol is not contained, the fatty acid glycerin ester produces glycerin in the presence of an acid in the first separation step. When the raw material contains a fatty acid salt, the fatty acid salt is converted into a free fatty acid by the acid, and it becomes easy to separate from glycerin.
Therefore, even when the raw material does not contain monohydric alcohol, the present embodiment can be suitably applied.

In the present embodiment, since the first separation step is performed in the presence of an inorganic acid, various raw materials can be processed at the same time. In addition, by performing the first separation step, wastes containing glycerin and fatty acid glycerin esters such as waste glycerin, waste cooking oil, and high acid value oil can be effectively utilized, which can contribute to reduction of environmental load. can.
Among them, high acid value oil has a high acid value of 10 mgKOH / g or more, so that it is difficult to use it as a raw material for the transesterification reaction using the alkali catalyst described above. However, in the first separation step, which can be called an acid-catalyzed esterification reaction, high acid value oil can also be suitably used as a raw material.

When waste glycerin, fatty acid glycerin ester-containing composition, etc. are used as raw materials, the fatty acid alkyl ester and free fatty acid produced in the first separation step move to the oil phase consisting of the first oil, so that the first glycerin Can be separated from the liquid. When the oil phase is recovered, the obtained first oil (fatty acid alkyl ester, free fatty acid, etc.) is subjected to a further esterification reaction (second esterification step described later), and finally bio. It can be used as a raw material for diesel fuel and the like. In addition, the obtained oil can be used as a compost material in addition to the production of fatty acid alkyl esters.
On the other hand, the first glycerin solution is acidified by the addition of an inorganic acid. In addition, the first glycerin solution contains an inorganic salt produced from an inorganic acid and an alkali contained in waste glycerin. A part of the inorganic salt may be precipitated, that is, the first glycerin solution may contain an acidic glycerin phase and the precipitated inorganic salt.

The raw material that can be used in the first separation step preferably has a water content of 10% by mass or less, and preferably 5% by mass or less. By using a raw material having a low water content (for example, waste glycerin having a low water content), it becomes easy to reduce the water content of the reaction solution described later. The water content of the raw material can be appropriately adjusted by heating, reducing the pressure, using a desiccant or the like, or permeating the purified glycerin.

Examples of the inorganic acid used in the first separation step include concentrated sulfuric acid, phosphoric acid, concentrated nitric acid, hydrogen chloride and the like, but concentrated sulfuric acid and phosphoric acid having a low water content are preferable, and concentrated sulfuric acid is particularly preferable.

In the first separation step, the pH of the mixed solution (reaction solution) of the raw material and the inorganic acid is preferably 3 or less, and particularly preferably 1 or less. The pH of the reaction solution can be adjusted by the amount of the above-mentioned inorganic acid added.
The reaction solution preferably has a water content of 10% by mass or less, and particularly preferably 0.5% by mass or less. The water content of the reaction solution can be appropriately adjusted by adjusting the water content and input amount of each raw material, using a desiccant in the reaction solution, and the like.
By setting the pH and water content of the reaction solution within the above ranges, the efficiency of the acid-catalyzed esterification reaction can be enhanced, and the first oil content and the first glycerin solution (including the acidic glycerin phase and the inorganic salt) can be increased. Can be well separated.

The temperature of the reaction solution in the first separation step can be 30 to 64 ° C, and further can be 50 to 60 ° C. The reaction time can be 0.5 to 12 hours, more can be 4 to 12 hours. During this time, it is preferable to stir the reaction solution.
After the above reaction (or stirring) is completed, the mixture is allowed to stand for 0.2 to 12 hours to contain the first oil containing fatty acid alkyl ester, unreacted fat and oil, and the first containing an acidic glycerin phase and an inorganic salt. Separates from the glycerin solution. The first oil component can be used for the production of fatty acid alkyl esters by subjecting it to a further esterification reaction (second esterification step described later). On the other hand, the first glycerin solution is subjected to the subsequent neutralization step.

(3) Neutralization Step The neutralization step is a step of neutralizing the first glycerin solution obtained in the first separation step with an alkaline substance.
As such an alkaline substance, hydroxides such as potassium hydroxide and sodium hydroxide can be used. Further, in the present embodiment, since the second separation step is performed after the neutralization step, various substances can be used as the alkaline substance.

For example, as the alkaline substance, a substance containing glycerin can be used. Examples of such glycerin-containing alkaline substances include the above-mentioned waste glycerin and the like, which are by-products of the alkali-catalyzed transesterification reaction of fats and oils. Since these can not only neutralize acidic glycerin but also increase the yield of glycerin, the use of a glycerin-containing alkaline substance is preferable from this viewpoint as well. The glycerin-containing alkaline substance may contain a fatty acid salt or a fatty acid glycerin ester.
The glycerin-containing alkaline substance preferably has a glycerin content of 25% by mass or more, and particularly preferably 50% by mass or more. The upper limit is not particularly limited, but may be, for example, 99% by mass or less, or 90% by mass or less.
The pH of the glycerin-containing alkaline substance is preferably 9 or more, and particularly preferably 9 to 13.

Further, as the alkaline substance, a composition containing a fatty acid salt as a main component may be used. Examples of the alkaline substance containing a fatty acid salt as a main component include oil slag and alkaline soap.

In the above neutralization step, the pH of the glycerin solution is adjusted to 4.0 to 7.5, further to 4.5 to 7.0, and particularly to 5.0 to 6.5. It is preferable to neutralize. By neutralizing the glycerin solution so that the pH is within such a range, the oil component can be easily separated and the inorganic salt can be easily precipitated in the subsequent second separation step. The pH of the glycerin solution can be appropriately adjusted by controlling the amount of the alkaline substance added.

The glycerin solution obtained in the neutralization step preferably has a water content of 10% by mass or less, and particularly preferably 3% by mass or less. In the neutralization step, there is no problem such as reaction inhibition by water, but from the viewpoint of sufficiently precipitating the inorganic salt in the subsequent second separation step to improve the separation efficiency, the upper limit of the water content is set as described above. It is preferable to specify. The lower limit of the water content is not particularly limited, but may be, for example, 0.5% by mass or more.

In the neutralization step, it is preferable to add the alkaline substance while stirring the acidic glycerin solution so that the liquid property shifts from acidic to near neutral. As described above, a substance containing a fatty acid salt may be used as the alkaline substance used for neutralization, but the fatty acid salt is converted into a free fatty acid by the acid by the addition order as described above. The free fatty acid shifts from the glycerin solution to the phase-separated oil phase, and even if the pH of the glycerin solution becomes high, it becomes difficult to redissolve in the glycerin solution. This makes the separation in the subsequent second separation step even easier. The fatty acid salt is contained not only in the above-mentioned substance containing a fatty acid salt as a main component, but also in a by-product of an alkali-catalyzed transesterification reaction of fats and oils and alkali hydrolysis.

The alkaline substance neutralizes the first glycerin solution obtained in the first separation step. The neutralized glycerin solution is subjected to the subsequent second separation step.

(4) Second Separation Step The second separation step is a step of separating the second oil component and the precipitated inorganic salt from the neutralized glycerin solution obtained in the neutralization step. The glycerin solution obtained by separating the second oil component and the precipitated inorganic salt by this step may be referred to as a second glycerin solution.

Here, the second oil to be separated includes fats and oils and fatty acids that were not separated even in the first separation step and remained in the first glycerin solution, as well as fats and oils derived from alkaline substances added in the neutralization step. Contains free fatty acids and the like.
The inorganic salt separated in the second separation step is a salt of an inorganic acid (concentrated sulfuric acid, etc.) added in the first separation step and an alkali (potassium, sodium, etc.), preferably potassium sulfate. Is. The alkali is contained in a raw material (waste glycerin, etc.) added to the first separation step or an alkaline substance added in the neutralization step, and an inorganic salt is contained in the first separation step or neutralization step. It is precipitated.

On the other hand, the second glycerin solution contains, in addition to glycerin, a monohydric alcohol derived from waste glycerin, and may contain water and the like. Since the oil and the inorganic salt have low solubility in the second glycerin solution, they are separated from the second glycerin solution.

In the second separation step, the neutralized raw material is allowed to stand for about 3 to 12 hours, and then the upper liquid (oil) and the lower liquid (second glycerin liquid) are separately recovered to become the lower liquid. Glycerin solution can be obtained, but it is preferable to increase the separation rate by centrifugation or the like. In such a centrifuge, a three-phase separation type centrifuge capable of separating a light liquid (that is, an oil content), a heavy liquid (that is, a second glycerin liquid) and a solid substance (that is, an inorganic salt) is preferably used. Can be done. Further, in the present embodiment, since a large amount of inorganic salt is precipitated, a certain amount of inorganic salt is separated in advance by a centrifuge capable of solid-liquid separation such as a decanter type, and then the liquid phase portion is further separated into three phases. It is also preferable to separate by a centrifuge.

The second oil content obtained in the second separation step is, for example, combined with the first oil content separated in the first separation step and subjected to a further esterification reaction (second esterification step described later). , Can be used to produce fatty acid alkyl esters. Further, the inorganic salt can be used as a raw material for an inorganic fertilizer or the like through, for example, a washing step or the like.
On the other hand, the second glycerin solution may contain water, and when a raw material containing a monohydric alcohol (waste glycerin or the like) is used, the monohydric alcohol is contained. If there is no problem in containing these, the second glycerin solution may be used as it is as purified glycerin. However, the monohydric alcohol may be removed by further subjecting the second glycerin solution to an alcohol separation step.

(5) Alcohol Separation Step The alcohol separation step is a step of separating monohydric alcohol from the second glycerin solution obtained in the second separation step.
The second glycerin solution may contain a monohydric alcohol derived from waste glycerin and remaining in the first separation step (acid-catalyzed esterification reaction). By separating (removing) such a monohydric alcohol, purified glycerin that can be applied to various uses can be obtained.

In the alcohol separation step, a vacuum distillation method, a gas-liquid contact method, a membrane separation method, or the like can be adopted.
The vacuum distillation method is a method in which a glycerin solution is heated (for example, about 60 ° C.) to evaporate the monohydric alcohol or the like, and then the pressure is reduced to separate the monohydric alcohol or the like. The separated monohydric alcohol or the like can be cooled and recovered.
The gas-liquid contact method is a method in which a glycerin solution is brought into contact with the gas phase as fine droplets, and a monohydric alcohol having a low boiling point is transferred to the gas phase for separation. Can be adopted.
The membrane separation method is a method using a membrane that preferentially permeates a monohydric alcohol.

The second glycerin solution may further contain water. When removing such water, for example, in a vacuum distillation method, a gas-liquid contact method, or the like, the water can be removed because it shifts to the gas phase together with the monohydric alcohol.
Further, before or after the alcohol separation step of separating the monohydric alcohol, further purification treatment may be carried out by using an ion exchange method, activated clay, diatomaceous earth, carbon, zeolite or the like.

The purified glycerin obtained as described above preferably has a purity of glycerin of 85% by mass or more, and particularly preferably 90% by mass or more. In the present embodiment, the glycerin-containing waste and the fatty acid glycerin ester-containing waste are relatively raw materials through the first separation step, the neutralization step, and the second separation step described above. Although it is a simple method, it is possible to obtain purified glycerin having a high purity as in the above numerical range.

The purified glycerin obtained by the method of the present embodiment can be used for various purposes such as industrial raw materials (for example, raw materials for fatty acid glycerin esters), asphalt-containing compositions and cement-containing composition release agents described later. Can be used.
Further, when it is desirable to further increase the purity of cosmetics, foods and drinks, pharmaceuticals, etc., a step such as distillation may be performed. Directly subjecting such a process from glycerin-containing waste requires a great deal of cost and energy, but since the purified glycerin obtained in the present embodiment has high purity, an operation for further increasing the purity (for example, distillation) is also possible. It's easy.

On the other hand, the separated monohydric alcohol can be purified as it is or, if necessary, by redistillation or the like, and reused as a raw material for an alkali-catalyzed transesterification reaction or an acid-catalyzed esterification reaction.

The design of each element in the above embodiment can be changed as appropriate. For example, the method for purifying glycerin according to the above embodiment may further include a second esterification step described below.

(6) Second Esterification Step In the first and second separation steps described above, the first and second oil components are recovered from the separated oil phase. Further, in the alcohol separation step described above, the separated monohydric alcohol is recovered. It is conceivable that these are circulated and supplied as raw materials in the production of fatty acid alkyl esters by the alkali catalyst method, but since the purity is not necessarily high, if they are used as raw materials as they are, the fatty acid alkyl esters can be efficiently produced. It can be difficult to do. Further, the first and / or second oils contain fats and oils having a high acid value such as free fatty acids, and in particular, the first oil can be said to be an esterification reaction using an acid catalyst. Since it was separated in one separation step (first esterification step), it has an acidic oil content. Therefore, it becomes more difficult to use the first and second oils as they are as a raw material for producing a fatty acid alkyl ester using an alkali catalyst.

However, if it is a method other than the alkali catalyst method, it is possible to produce a fatty acid alkyl ester even with a fat or oil having a high acid value. Therefore, in the present embodiment, it is preferable to include a second esterification step of producing the fatty acid alkyl ester by a method other than the alkali catalytic method.

In the second esterification step, it is preferable to use the first oil recovered in the first separation step and / or the second oil recovered in the second separation step as raw materials.
When the monohydric alcohol is recovered in the alcohol separation step, it is also preferable to use the recovered monohydric alcohol as a raw material.
As the other raw material, the same raw material (high acid value oil or the like) as in the above acid reaction step (first esterification step) can be used.

By using these as raw materials, it becomes possible to recycle industrial waste more efficiently in the above-mentioned purification of glycerin. Any method other than the alkaline catalyst method can be preferably used even with these raw materials.

The method that can be adopted in the second esterification step is a method other than the alkali catalyst method, and more specifically, an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, and the like. Subcritical methods and solid catalyst methods are exemplified. With these methods, transesterification reactions can be carried out with monohydric alcohols such as methanol, even if they are waste cooking oils and fats and oils having a high acid value, and even fats and oils containing unreacted free fatty acids. ..

In the second esterification step, glycerin is by-produced together with the oil containing the fatty acid alkyl ester. The oil content obtained in the second esterification step and the glycerin solution can be phase-separated by standing, centrifuging or the like. The separated oil can be used as a biodiesel fuel or the like by recovering the fatty acid alkyl ester. On the other hand, the by-produced glycerin can be supplied to the neutralization step together with the first glycerin solution obtained in the first separation step (first esterification step), for example. With this configuration, the glycerin produced as a by-product in the second esterification step can be made into a part of the glycerin solution through the neutralization step, the second separation step, and the like, so that it is more efficient. It can be recycled.

As the second esterification step, it is particularly preferable to adopt the acid catalyst method among the methods other than the alkali catalyst method described above.
As shown in FIG. 2, when the acid catalyst method is adopted as the second esterification step, the first oil component and / or the second oil component is used as a raw material. As the other raw material, the monohydric alcohol recovered in the alcohol separation step can be used, and further, the same raw material (high acid value oil, etc.) as in the first separation step (first esterification step) can be used. You may use it.
The reaction solution obtained in the second esterification step is separated into an oil component containing a fatty acid alkyl ester and a glycerin solution containing a by-produced glycerin, an acid catalyst and a salt thereof. Both the obtained oil and the glycerin solution are acidic, and the acidic glycerin solution can be supplied to the neutralization step or the like.

On the other hand, it is preferable to neutralize or dehydrate the oil containing the fatty acid alkyl ester. Here, as a method of neutralization / dehydration, a method using waste glycerin produced as a by-product in the production process of biodiesel fuel is preferably exemplified. Specifically, waste glycerin produced as a by-product in the manufacturing process of biodiesel fuel is dealcoholicized and stored in a tank or the like, and neutralizing oil is added from the lower part of the tank to bring it into contact with waste glycerin. .. As a result, the acidic oil is neutralized by the alkali of the waste glycerin, and the water and the monohydric alcohol contained in the oil are absorbed by the waste glycerin solution. Then, the oil charged from the lower part overflows from the upper part due to the difference in specific gravity, so that it can be easily recovered. By such a method, neutralization, dehydration and dealcoholization can be performed at the same time, and high quality oil can be easily obtained. The waste glycerin solution that has absorbed water and monohydric alcohol can be supplied to the above-mentioned neutralization step, and can be made into a part of purified glycerin through a second separation step and the like.

In the second esterification step, as a method other than the acid catalyst method, a biocatalyst method, a supercritical method, and a subcritical method can be preferably exemplified.
The biocatalyst method is a method of promoting a transesterification reaction by using a lipase or a phospholipase having a catalytic activity for a transesterification reaction. The biocatalyst method has a characteristic that the reaction conditions are mild, but the transesterification reaction can be promoted even for fats and oils having a high acid value, and there are few by-products.
In the supercritical method and the subcritical method, the temperature and pressure are adjusted to change the raw material to the supercritical state or the subcritical state, so that the phase state of the substance is changed from two phases of gas and liquid to two phases of liquid and liquid, and further the dielectric constant. This is a method of promoting hydrolysis by lowering the reaction system to one phase and changing the reaction system that originally required the use of a catalyst to a non-catalyst system.

By performing such a second esterification step, it becomes possible to recycle industrial waste more efficiently.

[Glycerin purification system]
A glycerin purification system according to an embodiment of the present invention, which can realize the method for purifying glycerin according to the above-described embodiment, will be described.

As shown in FIG. 3, the glycerin purification system 1 includes a first separation device 11, a neutralization device 12, a second separation device 13, and an alcohol separation device 14. The potassium sulfate production system 1 shown in FIG. 3 includes a storage tank 15 and a second esterification device 21.

The composition containing glycerin or fatty acid glycerin ester, which is a raw material, is put into the first separation device 11 together with the inorganic acid, and an acid-catalyzed transesterification reaction or the like is carried out. After a certain period of time, the reaction solution is phase-separated into an acidic glycerin phase (first glycerin solution) and an oil phase (first oil component).
The first glycerin solution contains glycerin, an inorganic salt, a monohydric alcohol and the like, and the first glycerin solution is supplied to the neutralizing device 12 and an alkaline substance is added to neutralize the first glycerin solution.

The neutralized glycerin solution obtained by neutralizing with the neutralizing device 12 is supplied to the second separation device 13 and separated into a second glycerin solution, an oil component (second oil component), and an inorganic salt. .. As the second separation device 13, a three-phase separation type centrifuge or the like can be preferably used, and a decanter type or other solid-liquid separable centrifuge or the like may be provided in front of the three-phase separation type centrifuge or the like.
The inorganic salt separated from the second separation device 13 can be used as fertilizer or the like.

A monohydric alcohol remains in the second glycerin solution separated by the separation device 13, and this is separated by the alcohol separation device 14. The purified glycerin from which the monohydric alcohol has been separated is stored in the storage tank 15. The obtained purified glycerin can be used for various purposes.

Further, in a preferred embodiment of the present embodiment, the glycerin purification system 1 further comprises a second esterification device 21. The second esterification apparatus 21 is composed of an esterification reaction tank for producing a fatty acid alkyl ester by a method other than the alkali catalyst method. The second esterification apparatus 21 contains the oil (first oil) separated by the first separator 11 and / or the oil (second oil) separated by the second separator 13. It is supplied, and further, the monohydric alcohol separated by the alcohol separation device 14 is supplied.
In the second esterification apparatus 21, a method other than the alkali catalyst method, more specifically, an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method or a solid. The catalytic method is carried out. An esterification reaction (including a transesterification reaction) is carried out by any of these methods to separate the oil containing the fatty acid alkyl ester from the glycerin solution. The by-produced glycerin solution can be, for example, supplied to the neutralization device 12 described above, neutralized and separated, and recycled as a raw material for glycerin.
When the esterification reaction is carried out by the acid catalyst method in the second esterification apparatus 21, the oil containing the fatty acid alkyl ester is acidic. Such acidic oil may be neutralized, dehydrated, and dealcoholicized at the same time by injecting the acidic oil from the lower part of a tank or the like (not shown) storing waste glycerin and overflowing it to the upper part of the glycerin phase.

[Manufacturing method of release agent]
The method for producing a release agent for an asphalt or cement-containing composition according to an embodiment of the present invention is a purification method obtained by separating the purified glycerin obtained in the above embodiment, particularly a monohydric alcohol by an alcohol separation step. Glycerin is an essential component of the release agent.
In addition, in this specification, "a release agent of a composition containing asphalt or cement" (hereinafter, may be simply referred to as "a release agent") is a release of an adhesion inhibitor of an asphalt-containing composition or a cement-containing composition. It is a concept including a mold, and the same applies to the "peeling method".

Generally, asphalt used for road pavement or the like is mixed with asphalt and aggregate at a factory, and the obtained mixture is placed on a truck bed and transported to a construction site. However, asphalt adheres to factory equipment such as hoppers, transportation equipment such as dump carriers, and pavement equipment such as finishers, and it takes time to unload asphalt at the construction site, or some asphalt is wasted. There is a problem such as becoming.

On the other hand, cement is mixed with aggregates and the like and used as mortar and concrete (hereinafter sometimes referred to as "concrete and the like") in factories and construction sites. Here, concrete or the like may adhere to the mixer, the agitator, or the like, which requires cleaning the mixer, the agitator, or the like, which requires a great deal of labor. In addition, it is common to pour concrete or the like into a formwork to form a structure and remove the formwork after the concrete or the like has hardened. However, if concrete or the like adheres to the formwork, it is difficult to remove the formwork. At the same time, there is a problem that the surface of the obtained cured product is damaged.

To solve the above problems, a method of applying a release agent to the surface of a truck bed, a mixer / agitator, a formwork, or the like, which can come into contact with an asphalt mixture or concrete, is known. Conventionally, mineral oils such as light oil have been widely used as such release agents. However, mineral oil has a problem of eluting asphalt, and is not preferable from the viewpoint of the influence on the health of workers and the environmental load.

On the other hand, the release agent of the present embodiment has an excellent release effect of the composition containing asphalt or cement by using purified glycerin as an essential component of the release agent. Further, since purified glycerin is a biodegradable naturally-derived substance that does not easily elute asphalt, the risk of adverse effects on the health of workers and environmental load is extremely small.

Attempts have been proposed to use waste glycerin, which is produced as a by-product in the manufacturing process of biodiesel fuel, as a release agent. However, as described above, waste glycerin contains unreacted fatty acids and salts thereof, monohydric alcohols such as methanol, and catalyst alkalis in high concentrations in addition to glycerin, and these are used as they are as a release agent. When used, it may adversely affect compositions containing asphalt or cement.
However, the glycerin purified by the above purification method has a reduced content of oil, inorganic salt, monohydric alcohol, etc., and exhibits a sufficient peeling effect. Therefore, a stripping agent for a composition containing asphalt or cement. Can be suitably used as. Further, there is a problem that the quality of waste glycerin is not constant due to the use of various fats and oils as a raw material for biodiesel fuel. However, according to the present embodiment, a release agent having stable quality is provided. Is possible. Further, according to the present embodiment, inexpensive waste glycerin can be particularly preferably used as a raw material for a release agent, and the environmental load can be reduced from the viewpoint that waste glycerin, which is an industrial waste, can be effectively used. can.

As described above, in the method for producing the release agent according to the present embodiment, the purified glycerin obtained by the above purification method, particularly the purified glycerin obtained by separating the monohydric alcohol by the alcohol separation step, is essential for the release agent. As long as it is an ingredient, it is not particularly limited. Such purified glycerin can be used as it is as a release agent.
However, the purified glycerin may cause a problem of workability. When it is desirable to avoid such a problem, it is preferable to further perform an oil content removing step, an oil content separation suppressing step, and a dilution step.

Hereinafter, a particularly preferable embodiment of the present embodiment will be described with reference to FIG. FIG. 4 is a diagram showing a flow in a particularly preferable embodiment of the method for producing a release agent according to the present embodiment. In FIG. 4, an oil content removing step, an oil content separation suppressing step, and a dilution step, which are optional steps, are shown.

Here, in the purified glycerin, a small amount of oil such as fatty acid glycerin ester and free fatty acid may remain. These are well dissolved in purified glycerin and do not impair the exfoliation effect. However, when purified glycerin is diluted, these oils cannot be dissolved in water and may undergo phase separation as oils. Further, when a hydrophilic phase of neutralized sweet water or fatty acid alkyl ester washing wastewater is used in the dilution step described later, the oil content derived from these may also be phase-separated after dilution. The phase-separated oil may have an unfavorable effect on the release agent storage system, the liquid transfer system, and the like.
In order to avoid such an effect, oil may be removed from the refined glycerin (oil removal step), or a predetermined surfactant may be added to suppress phase separation (oil separation suppressing step).

(1) Oil removal step The specific method in the oil removal step is not particularly limited, and in addition to separating oil by static separation, centrifugation, membrane separation, filter removal, etc., activated clay, diatomaceous earth, activated carbon, silica gel, zeolite, etc. , The oil may be removed by adsorbing it on an adsorbent such as a molecular sieve, or these may be combined as appropriate. For example, as a preferred embodiment, most of the remaining oil is separated and removed by static separation or centrifugation, and then by membrane separation, filter removal, adsorbent, etc., the remaining oil, the dye, and the remaining inorganic salt are used. There is also a method of removing impurities such as.

In addition, it is one of the particularly preferable embodiments to add a predetermined surfactant in order to promote the separation of the oil component. Specifically, a surfactant having an HLB value of 14 or less, more preferably 13 or less is added. The lower limit of the HLB value is not particularly limited, but may be, for example, 8 or more, or 10 or more. The HLB value in the present specification is an HLB calculated value of Griffin.
The type of surfactant for promoting oil separation is not particularly limited as long as it has the above HLB value, but it is preferably a biodegradable surfactant, and it is a nonionic surfactant. Is preferable. More specifically, it is preferably polyoxyethylene alkyl ether.

The amount of the surfactant added is not particularly limited as long as the oil separation promoting effect is exhibited, but for example, it is 0.05% by mass or more, preferably 0.1% by mass or more, more preferably 0.15 with respect to the release agent. When added in an amount of mass% or more, the oil content separation promoting effect is suitably exhibited.
On the other hand, the upper limit of the amount of the surfactant added is not particularly limited, but when the wettability with light oil can be a problem as described later, it is 10% by mass or less, preferably 5% by mass or less with respect to the release agent. When added in such a manner, the wettability with light oil is not significantly impaired.

The above-mentioned surfactant can be added at any timing. For example, in the dilution step described later, it may be added to purified glycerin at the same time as water or an aqueous solution used for dilution, or it may be diluted with water or an aqueous solution to which the above-mentioned surfactant is added. Further, the above-mentioned surfactant may be added to the diluted release agent.
Further, as shown in FIG. 4, the above-mentioned surfactant is added to the purified glycerin before dilution to separate and remove the oil, and the purified glycerin from which the oil has been separated is subjected to a further step such as a dilution step. You may.

Since the addition of such a surfactant promotes the separation of the oil component, the oil component can be separated by a simple method such as static separation or centrifugation. In the case of static separation, the static time may be, for example, 2 hours or more, 24 hours or more, or 3 days or more.
Since the oil component is separated into the upper layer of the glycerin solution, the oil component can be removed by recovering the lower layer which is the glycerin solution.

The removed oil (third oil) may be recovered and reused. For example, it can be used for the production of fatty acid alkyl esters by combining it with the first and second oils separated in the first and second separation steps described above and subjecting it to a further acid-catalyzed esterification reaction or the like.

(2) Oil Separation Suppressing Step The oil separation suppressing step is a step of suppressing oil separation by adding a predetermined surfactant. It may be carried out directly on the purified glycerin obtained by the above-mentioned purification method, but it is preferably carried out on the glycerin subjected to the above-mentioned oil removal step. Since a considerable amount of oil is removed in advance by performing the oil separation suppressing step after the oil removing step, further oil separation is effectively suppressed.

The surfactant added in this step preferably has an HLB value of 15 or more, and particularly preferably 17 or more.
The type of surfactant is not particularly limited as long as it has the above HLB value, but it is preferably biodegradable and preferably a nonionic surfactant. More specifically, polyoxyethylene alkyl ether is particularly preferable.

The amount of the surfactant added is not particularly limited as long as the effect of suppressing oil separation is exhibited, but is added so as to be, for example, 0.05% by mass or more, preferably 0.1% by mass or more with respect to the release agent. Then, the effect of suppressing oil separation is preferably exhibited. Further, in the use of the release agent according to the present embodiment, if the wettability with other release agents (for example, light oil) used up to that point may be a problem, the release agent may be added at a higher concentration. .. Specifically, it may be added so as to be 1% by mass or more and further 2% by mass or more with respect to the release agent.
On the other hand, the upper limit of the amount of the surfactant added is not particularly limited, but may be, for example, 10% by mass or less, more preferably 5% by mass or less, based on the release agent.

(3) Dilution Step The dilution step is a step of diluting the purified glycerin. Workability can be improved by diluting purified glycerin, which has a high viscosity.
In FIG. 4, the dilution step is shown after the oil content removing step and the oil content separation suppressing step, but the present embodiment is not limited to this order. For example, after diluting the purified glycerin by a dilution step, it may be subjected to an oil content removing step or an oil content separation suppressing step.

Water such as tap water can be appropriately used for dilution. Further, an aqueous solution containing glycerin such as neutralized sweet water and the hydrophilic phase of the washing wastewater of the fatty acid alkyl ester may be used as long as the peeling effect according to the present embodiment is not impaired.

Here, the neutralized sweet water is obtained by neutralizing the above-mentioned sweet water (a by-product in the case of saponifying fats and oils to produce fatty acid salts), and contains glycerin, water, and a small amount of inorganic salts. .. The hydrophilic phase of the washing wastewater of the fatty acid alkyl ester is obtained by removing free fatty acids and salts thereof from the washing wastewater of the fatty acid alkyl ester described above, and contains water, glycerin, monohydric alcohol and the like.
Since these aqueous solutions containing glycerin may contain fatty acids, fatty acid alkyl esters, and the like, when these are used for dilution, it is preferable to perform them before the oil content removing step or the oil content separation suppressing step.
The hydrophilic phase of neutralized sweet water and fatty acid alkyl ester washed wastewater is an aqueous solution containing components other than glycerin, but if the amount used is adjusted, the peeling effect will not be hindered, and these are industrial wastes that can be effectively used. Therefore, the environmental load can be reduced.

The dilution ratio is not particularly limited as long as the peeling effect is exhibited, but for example, when diluting with water, purified glycerin: water may be 1: 0.5 to 1: 4, and 1: 2 to 1. It may be 1: 4.

The release agent obtained as described above may contain an additive as long as the effect of the present embodiment is not impaired. Examples of such additives include pH adjusters, bactericides, chelating agents, pigments, fragrances and the like.

The release agent produced by the above method is excellent in the release effect of the composition containing asphalt or cement and has biodegradability, so that the environmental load is small. Further, according to the method for producing a release agent of the present embodiment, waste glycerin, which is an industrial waste, can be effectively utilized, so that the environmental load can be reduced from such a viewpoint, and further, the utility value is low in the past. Oils and fats such as high acid value oils that have been used can also be effectively used as raw materials.

[Peeling method]
The method for peeling a composition containing asphalt or cement according to an embodiment of the present invention is a peeling method in which the peeling agent obtained by the above-described embodiment is treated on a surface to which the composition containing asphalt or cement can come into contact. It is provided with a processing process.

Here, among the compositions subject to the present embodiment, examples of the asphalt-containing composition include a mixture of asphalt and aggregate (asphalt mixture). Surfaces that the asphalt-containing composition can come into contact with include compound factory equipment such as hoppers, skip elevators, and rotary kilns; dump truck carriers used for transportation; paving equipment such as finishers, macadam rollers, tire rollers, and scoops; Can be mentioned.
Examples of the cement-containing composition include concrete and the like (mortar and concrete) which are a mixture of cement and aggregate, and the surface on which the cement-containing composition can come into contact is used for transporting the cement-containing composition. Examples include the inner surface of a mixer and agitator, and a formwork for molding concrete and the like.

In the present embodiment, the release agent is treated on the surface to which the asphalt-containing composition or the cement-containing composition can come into contact. The treatment method is not particularly limited, and for example, the release agent may be appropriately diluted with water or the like, and applied or sprayed on a contactable surface.

A release agent (for example, light oil or the like) different from the release agent of the present embodiment may be used on the surface to which the asphalt-containing composition or the cement-containing composition may come into contact. Then, depending on the type of the release agent used up to that point, the release agent of the present embodiment may be repelled, and wettability may become a problem. In such a case, the release agent used up to that point may be washed with soap or the like and then treated with the release agent of the present embodiment, but cleaning wastewater will be generated.
Therefore, in order to improve the wettability of the release agent used in the present embodiment, it is preferable to add a predetermined surfactant. As such a surfactant, for example, a surfactant that can be used in the oil separation suppressing step in the above-mentioned method for producing a release agent can be preferably exemplified. By adding such a surfactant, it is possible to improve the wettability of the surface treated with another release agent such as light oil without cleaning.

The amount of the surfactant added is not particularly limited as long as the effect of improving the wettability is exhibited, and is, for example, 0.05% by mass or more, 0.1% by mass or more, 1% by mass or more, and 2 with respect to the release agent. When added in an amount of mass% or more, the effect of improving wettability is particularly preferably exhibited. On the other hand, the upper limit of the amount of the surfactant added is not particularly limited, but may be, for example, 10% by mass or less, more preferably 5% by mass or less, based on the release agent.

According to the above peeling method, the composition containing asphalt or cement is excellent in peeling effect and has biodegradability, so that the environmental load is small. Further, since the content of alcohol, inorganic salt, etc. is low, there is little possibility of adversely affecting the composition containing asphalt or cement, and unlike mineral oil, the effect of not causing cutback of asphalt or the like is also obtained.

The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

Hereinafter, the present invention will be described in more detail by showing examples and the like, but the present invention is not limited to the following examples and the like.

[Production Example 1] Purification of glycerin (preparation of waste glycerin)
A biodiesel fuel was produced by transesterifying waste cooking oil and methanol by an alkaline catalyst method using potassium hydroxide as a catalyst. The by-product containing glycerin produced at this time was recovered as waste glycerin.

To this waste glycerin, 20 g of zeolite was added per 1 kg of waste glycerin to remove water. The zeolite-added waste glycerin was passed through a 250 mesh filter to remove zeolite and solid impurities.
The composition and physical properties of the waste glycerin as a raw material thus obtained (hereinafter, referred to as “raw material waste glycerin”) are as shown in Table 1.

(First separation step)
500 kg of raw material waste glycerin and 300 kg of high acid value oil (150 mgKOH / g) were put into a reaction tank having a capacity of 1000 L and having a heating / cooling function, and heated to 55 ° C. with stirring (120 rpm). In this state, 32 L of concentrated sulfuric acid was added into the reaction vessel over 15 minutes. When adding concentrated sulfuric acid, care was taken so that the temperature of the mixture in the reaction vessel did not exceed 65 ° C. The pH of the reaction solution after the total amount of concentrated sulfuric acid was added was 1. After the addition of concentrated sulfuric acid was completed, stirring was continued for 240 minutes. After that, it is allowed to stand for 10 hours to separate it into an oil phase (first oil content) and an acidic glycerin phase (first glycerin solution), and the first glycerin solution (including the acidic glycerin phase and precipitated potassium sulfate) is recovered. bottom. By repeating the above operation, 5000 kg of the first glycerin solution was obtained.

(Neutralization process)
5000 kg of the first glycerin solution and 5000 kg of waste glycerin were put into a reaction tank having a capacity of 15,000 L while stirring. The pH was 5.0. After that, stirring was continued for 4 hours, and then the mixture was allowed to stand for 24 hours.

(Second separation step)
The neutralized glycerin was treated with a decanter type centrifuge (product name: Z18HV, manufactured by Tanabe Wiltec) at 5500 rpm for 180 minutes, and the precipitated potassium sulfate was separated and recovered. The liquid phase was further treated with a three-phase separator (manufactured by Alfa Laval) at 8000 rpm for 180 minutes, and the second oil, the second glycerin solution, and potassium sulfate were separated and recovered, respectively.

(Alcohol separation process)
The second glycerin solution obtained by the three-phase separation was distilled in a batch system at a distillation temperature of 110 ° C. for 10 minutes using a vacuum distillation apparatus to remove methanol to obtain purified glycerin.

[Production Example 2] Distillation of purified glycerin Using 11.925 g of the purified glycerin obtained in Production Example 1, vacuum distillation was performed. The pressure was reduced to 30 Pa with a vacuum pump, and the temperature was raised from 50 ° C. Moisture was vaporized at around 80 ° C., and glycerin was vaporized at around 160 to 170 ° C., so each was recovered. After reaching 200 ° C. and maintaining the temperature for 20 minutes, vacuum distillation was completed.

By the above vacuum distillation, 11.256 g of distilled glycerin (yield 94.4% by mass), 0.427 g of water and 0.242 g of residue were obtained. When distilled glycerin was analyzed by HPLC, the purity was 99% or more.
From the result of vacuum distillation, it was confirmed that the purity of the purified glycerin obtained in Production Example 1 was 94% by mass or more.
Further, it was recognized that the distilled glycerin obtained in this production example has high purity and can be applied to various uses such as cosmetics, industrial raw materials, and foods and drinks.

[Production Example 3] Production of release agent The purified glycerin obtained in Production Example 1 was diluted with water until it had a specific gravity of 1.11 and allowed to stand for 1 week. The oil (and contaminants) was removed by passing through a column packed with a bag filter of 5 microns and activated clay to obtain a release agent.

[Test Example 1] Peeling (prevention of adhesion) test The peeling (prevention of adhesion) effect of the release agent obtained in Production Example 3 was tested as follows.
^{Apply 0.2 L / m 2 of} release agent to the iron plate, place 5 kg of porous asphalt mixture on it, flatten it, and when the temperature of the mixture reaches 90 ° C, lift and tilt one of the iron plates, and the angle at which the mixture slides down. Was measured. The results are shown in Table 2.

As shown in Table 2, the release agent of the product of the present invention was excellent in the release effect of the asphalt mixture.

[Test Example 2] Asphalt dissolution test No. 6 crushed stone coated with polymer-modified asphalt type II is arranged in a white container, and the release agent (10-fold dilution) and light oil obtained in Production Example 3 are poured to soak the asphalt mixture. Asphalt elution was confirmed after allowing to stand at room temperature for 6 hours. The results are shown in FIG.

As shown in FIG. 2, the release agent of the product of the present invention did not elute asphalt. On the other hand, asphalt elution was confirmed in light oil.

[Test Example 3] Wetting property evaluation test The release agent obtained in Production Example 3 is blended with the following surfactant (see Table 3 for the final concentration), and the release agent for wettability evaluation (Samples 1 to 1). 4) was obtained.
Softanol 400: manufactured by Nippon Shokubai Co., Ltd., HLB value: 18.0, polyoxyethylene alkyl ether (secondary alcohol ethoxylate), EO addition molar number: 40, carbon number of alkyl group portion of secondary alcohol: 12 to 12 14
Softanol 70: manufactured by Nippon Shokubai Co., Ltd., HLB value: 12.1, polyoxyethylene alkyl ether (secondary alcohol ethoxylate), number of moles added with EO: 7, carbon number of alkyl group portion of secondary alcohol: 12 to 12 14

Light oil was applied to one surface of an iron plate (10 cm × 20 cm) using a sprayer, and a 20 cm piece was held at an angle of about 15 °. The release agent of Samples 1 to 4 was further applied on the light oil surface of the iron plate, and the wettability with respect to the light oil surface was evaluated according to the following criteria. The results are shown in Table 3.

= Evaluation criteria for wettability =
A: No repelling is observed, and it fits well on the light oil level (very good).
B: Slight repelling occurs, but it is familiar with the light oil level (good)
C: Repelling occurs, and some parts are not compatible with the light oil level (possible)
D: Repelling occurs on the entire surface and is not familiar on the entire surface of the light oil surface (defective).

As shown in Table 3, the release agent containing the surfactant had improved wettability with respect to the light oil surface, and the release agents of Samples 2 and 4 had particularly good wettability with respect to light oil. The release agent of Sample 4 in which a surfactant having a high HLB value and a surfactant having a low HLB value were used in combination was more compatible with the light oil surface than the release agent of Sample 2.
As described above, by blending a surfactant having a high HLB value with the release agent of the present invention, the release agent of the present invention can be applied without cleaning the light oil even on the surface to which the light oil has been applied. It was shown to be.

[Test Example 4] Oil Separation Test Using the release agent (turbidity 1.563) obtained in Production Example 3, the primary treatment (oil removal step) and secondary treatment (oil separation suppression step) are performed as follows. The turbidity and the state of oil adhesion to the container wall surface were observed.

(Primary processing)
Put 400 mL each of the release agent (specific gravity 1.11 and turbidity 1.563) obtained in Production Example 3 into a 500 mL beaker, and further add three types of low HLB surfactants (sophanols 30, 50 and 70), respectively. A total of 7 test groups were provided, including the non-additive group, with the addition of 0.1% or 0.2% concentration. Each test group was stirred with a magnetic stirrer at 400 rpm for 60 minutes, and then 300 mL was dispensed into a 300 mL separatory funnel. Each test plot dispensed into a separatory funnel was allowed to stand for 7 days.
After standing, 275 mL of the lower liquid was withdrawn from under the separatory funnel, and the obtained lower liquid was used as the primary treatment liquid.
The turbidity of each test group after the primary treatment was determined as the turbidity of the surfactant-free group immediately after stirring in the secondary treatment described below.

(Secondary processing)
50 mL of each test group for the primary treatment was placed in a 100 mL beaker, and two types of high HLB surfactants (Sophanol 400 and 500) were added at a concentration of 0.1% or 0.2%, respectively. Together with the additive-free plots, 5 test plots were set for each test plot for the primary treatment, for a total of 35 test plots. Each test group was stirred with a magnetic stirrer 400 rpm for 60 minutes, and the turbidity of all test groups was measured immediately after stirring.

45 mL of each of the stirred test plots was dispensed into a 50 mL simple separatory funnel (50 mL syringe + cock). Each test plot dispensed into a simple separatory funnel was allowed to stand for 23 days. After standing, 35 mL of the lower liquid of the simple separatory funnel was withdrawn, and the turbidity of the lower liquid after the secondary treatment and the state of oil adhesion to the wall surface of the simple separatory funnel were observed.

Here, in this test, the following surfactants were used.
(Primary processing)
Softanol 30: manufactured by Nippon Shokubai Co., Ltd., HLB value: 7.9, polyoxyethylene alkyl ether (secondary alcohol ethoxylate), number of moles added with EO: 3, number of carbon atoms in the alkyl group portion of the secondary alcohol: 12 to 12 14
Softanol 50: manufactured by Nippon Shokubai Co., Ltd., HLB value: 10.5, polyoxyethylene alkyl ether (secondary alcohol ethoxylate), number of moles added with EO: 5, carbon number of alkyl group portion of secondary alcohol: 12 to 12 14
Softanol 70: manufactured by Nippon Shokubai Co., Ltd., HLB value: 12.1, polyoxyethylene alkyl ether (secondary alcohol ethoxylate), number of moles added with EO: 7, carbon number of alkyl group portion of secondary alcohol: 12 to 12 14
(Secondary processing)
Softanol 400: manufactured by Nippon Shokubai Co., Ltd., HLB value: 18.0, polyoxyethylene alkyl ether (secondary alcohol ethoxylate), EO addition molar number: 40, carbon number of alkyl group portion of secondary alcohol: 12 to 12 14
Softanol 500: manufactured by Nippon Shokubai Co., Ltd., HLB value: 18.3, polyoxyethylene alkyl ether (secondary alcohol ethoxylate), EO addition molar number: 50, carbon number of alkyl group portion of secondary alcohol: 12 to 12 14

The turbidity of the release agent was 1.563 before the primary treatment, but by allowing it to stand for 7 days, the turbidity decreased to 1.244 even in the surfactant-free group. This reflects that the turbidity of the lower liquid decreased as a result of the oil component, which is the cause of the turbidity, separating into the upper part after being allowed to stand for 7 days.
On the other hand, by adding a low HLB surfactant in the primary treatment, the turbidity after the primary treatment (upper part of each column) is reduced to 0.419 to 0.977, and oil separation is promoted. Was there.

Furthermore, by adding a high HLB surfactant in the secondary treatment, the turbidity immediately after the secondary treatment (upper part of each column) was lower than that after the primary treatment. Since the high HLB surfactant solubilizes the oil content, it is considered that the turbidity is reduced.
In some test plots, the turbidity (lower part of each column) after 23 days of the secondary treatment decreased and adhered to the wall surface of the simple separatory funnel (indicated by * in the table). These indicate that the oil was further separated after 23 days of the secondary treatment. However, in the test group to which the surfactant was added in the secondary treatment, oil separation was suppressed as compared with the group in which the surfactant was not added in the secondary treatment.

From the obtained results, the test group in which 0.2% of sophthalol 70 (HLB value: 12.1) was added in the primary treatment and sophthalol 400 (HLB value: 18.0) was added in the secondary treatment was optimal. It was recognized that the processing conditions were favorable.

According to the present invention, refined glycerin applicable to various uses can be obtained from waste glycerin, high acid value oil, etc., which have been conventionally considered to have low utility value, and have great industrial utility value. There is. Further, according to the present invention, it is possible to provide a peeling agent and a peeling method which are excellent in peeling effect of a composition containing asphalt or cement and have a low environmental load.

1: Glycerin purification system 11: First separation device 12: Neutralizer 13: Second separation device 14: Alcohol separation device 15: Storage tank 21: Second esterification device

Claims (18)

A method for purifying glycerin from a raw material containing at least one of glycerin and a fatty acid glycerin ester.
The first separation step of mixing the raw material and the inorganic acid to separate the first oil component and the first glycerin solution, and
A neutralization step of neutralizing the first glycerin solution with an alkaline substance, and
A second separation step that separates the second oil and precipitated inorganic salts from the neutralized glycerin solution, and
A method for purifying glycerin, which comprises. The method for purifying glycerin according to claim 1, wherein the raw material contains waste glycerin produced as a by-product in the process of producing a biodiesel fuel. The method for purifying glycerin according to claim 1 or 2, wherein the raw material contains a high acid value oil having an acid value of 10 mgKOH / g or more. The method for purifying glycerin according to any one of claims 1 to 3, wherein the pH of the mixed solution of the raw material and the inorganic acid is 3 or less. The method for purifying glycerin according to any one of claims 1 to 4, wherein the inorganic acid is concentrated sulfuric acid. The method for purifying glycerin according to any one of claims 1 to 5, wherein in the neutralization step, the pH of the glycerin solution is neutralized to be 4.0 to 7.5. The method for purifying glycerin according to any one of claims 1 to 6, wherein the alkaline substance contains waste glycerin and / or oil residue. The method for purifying glycerin according to any one of claims 1 to 7, further comprising an alcohol separation step of separating a monohydric alcohol from the glycerin solution obtained in the second separation step. At least one method other than the alkali catalyst method, which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method. A second esterification step is provided to produce a fatty acid alkyl ester.
In the second esterification step, the first oil separated in the first separation step and / or the second oil separated in the second separation step is used as a raw material.
The method for purifying glycerin according to any one of claims 1 to 8. A system for purifying glycerin from a raw material containing at least one of glycerin and fatty acid glycerin ester.
A first separation device that mixes the raw material and an inorganic acid to separate the first oil and the first glycerin solution.
A neutralizer that neutralizes the first glycerin solution with an alkaline substance,
A second separator that separates the second oil and precipitated inorganic salts from the neutralized glycerin solution,
A glycerin purification system characterized by comprising. The glycerin purification system according to claim 10, further comprising an alcohol separation device for separating a monohydric alcohol from the glycerin solution from which the second oil component and the inorganic salt have been separated, after the second separation device. A method for producing a release agent for a composition containing asphalt or cement, which comprises using the purified glycerin obtained by the method according to claim 8 as an essential component of the release agent. The method for producing a release agent according to claim 12, further comprising an oil component removing step of removing the third oil component separated from the refined glycerin. The method for producing a release agent according to claim 13, wherein a surfactant having an HLB value of 14 or less is added to the purified glycerin in the oil removal step. The method for producing a release agent according to claim 14, wherein the surfactant having an HLB value of 14 or less is a nonionic surfactant. The method for producing a release agent according to any one of claims 13 to 15, wherein a nonionic surfactant having an HLB value of 15 or more is added to the glycerin solution from which the third oil component has been separated. The method for producing a release agent according to any one of claims 12 to 16, further comprising a dilution step of diluting the purified glycerin. Contains asphalt or cement, characterized in that the release agent produced by the method according to any one of claims 12 to 17 is treated on a surface to which the composition containing the asphalt or cement can come into contact. Method of peeling the composition.

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