JP6951907B2 - Water treatment method, water treatment system, denitrifying agent manufacturing method and denitrifying agent manufacturing equipment - Google Patents

Description

The present invention relates to a water treatment method, a water treatment system, a denitrifying agent manufacturing method, and a denitrifying agent manufacturing apparatus for performing a biological nitrification denitrification treatment by adding an organic carbon source.

A method of adding a monohydric alcohol such as methanol and an alkali catalyst to waste cooking oil as a raw material to promote a transesterification reaction to produce a fatty acid alkyl ester as a biodiesel fuel is a method of obtaining a carbon-neutral gas oil alternative fuel. Attention has been paid.

Patent Document 1 discloses a water treatment method using a crude glycerin waste liquid that can be inexpensively post-treated and can be reused in a large amount, which is difficult to treat as a by-product in the manufacturing process of biodiesel fuel. ing.

It is a water treatment method that uses a nitrification denitrification method that uses an organic carbon source for denitrification treatment. It is a water treatment method including a denitrification treatment step of adding the extracted aqueous layer as an organic carbon source of a biological nitrification denitrification treatment using a dependent nutrient microorganism.

According to the water treatment method, not only the increase in chemical cost due to the addition of a large amount of methanol as an organic carbon source in the denitrification treatment step is eliminated, but also the use of methanol derived from fossil fuel is eliminated, so that the greenhouse effect is achieved. It also leads to the reduction of gas emissions.

Japanese Unexamined Patent Publication No. 2013-202549

However, when the water treatment method described in Patent Document 1 is adopted, the aqueous layer taken out in the separation step contains various salts and methanol that did not contribute to the transesterification reaction in addition to glycerin as the main component. As a result, the following new issues have arisen.

From the viewpoint of suppressing greenhouse gas emissions, it is not preferable to use the water layer containing fossil fuel-derived methanol as it is as a denitrifying agent from the viewpoint of controlling greenhouse gases.

In addition, since it contains a certain amount of methanol, it is classified as a Class 4 flammable liquid designated combustible material under the Fire Service Act, and when it is stored in excess of the specified quantity, non-hazardous materials are removed by the conventional water treatment method. There was also a problem that the 50% methanol storage tank used as a nitrogenant could not be used as it was. The same problem occurs not only in the transesterification reaction using methanol but also in the method for producing a fatty acid alkyl ester produced by the transesterification reaction using a monohydric alcohol such as ethanol or propanol.

Designated combustibles include ^{combustible liquids of 2 m 3} or more. The flammable liquids are liquids having a flash point of 40 ° C. or higher and lower than 70 ° C. at 1 atm, a flammable liquid amount of 40% or less, and a burning point of 60 ° C. or higher.

In view of the above-mentioned problems, an object of the present invention is a water treatment method, a water treatment system, a denitrifying agent manufacturing method, and a denitrifying agent, which can suppress greenhouse gas emissions and can use existing equipment as they are. The point is to provide the manufacturing equipment of.

In order to achieve the above object, the first characteristic composition of the water treatment method according to the present invention is a water treatment method in which an organic carbon source is added to perform a biological nitrification and denitrification treatment, using fats and oils as a raw material. From the oil layer separation step of separating the oil layer containing fatty acid from the crude glycerin waste liquid produced as a by-product in the primary production step of the fatty acid alkyl ester to take out the aqueous layer containing glycerin, and from the aqueous layer taken out in the oil layer separation step. An alcohol separation step of separating a monohydric alcohol and a denitrification treatment step of adding an aqueous layer from which the monovalent alcohol was separated in the alcohol separation step as an organic carbon source for the biological nitrification denitrification treatment. unrealized, the oil layer separation step acid-catalyzed process excluding alkali catalyst method and a separated oil layer monohydric alcohol separated by the alcohol separation step, the alkali catalyst method, biocatalytic method, an ion-exchange resin method, A crude glycerin waste liquid produced as a by-product in the secondary production step is provided with a secondary production step of the fatty acid alkyl ester for producing the fatty acid alkyl ester by using any of the supercritical method, the subcritical method and the solid catalyst method. The point is that it is configured to be supplied to the oil layer separation step.

The oil layer containing fatty acids is separated from the crude glycerin waste liquid, the aqueous layer containing glycerin is taken out by the oil layer separation step, and the monohydric alcohol contained in the aqueous layer is separated by the alcohol separation step. An aqueous layer as a non-hazardous substance whose flash point is no longer detected by separating a highly flammable monohydric alcohol from the glycerin, salt, etc., instead of 50% methanol, which has been conventionally used as a denitrifying agent. Is added as an organic carbon source for biological nitrification and denitrification treatments with heterotrophic microorganisms. As a result, it becomes possible to suppress greenhouse gas emissions and to store the water layer in a state where legal regulations are satisfied using existing equipment. When an alkaline catalyst method is used as the oil layer separation step, for example, the oil layer and the aqueous layer can be separated by a static method, a centrifugal separation method, a membrane separation method, or the like after neutralization treatment with an acid. Examples of the separation step include a distillation method, a membrane separation method, and an ion exchange method.

The oil layer separated in the oil layer separation step contains a large amount of fats and oils having a high acid value such as free fatty acids, and the purity of the monohydric alcohol separated in the alcohol separation step is not so high, so all of them are as they are. It is difficult to reuse in the state to produce fatty acid alkyl esters that will be biodiesel fuels using the alkaline catalytic method. However, even such oils and fats with high acid value and monohydric alcohols with low purity can be used as fatty acid alkyl esters as biodiesel fuel if a secondary production process using a method other than the alkali catalyst method is adopted. It becomes possible to efficiently recycle resources, and the crude glycerin waste liquid produced at that time is supplied to the oil layer separation step, and after the oil layer is separated, an organic carbon source for bionitrification and denitrification treatment is performed. It will be possible to utilize it as. Any one 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 can be adopted for such a secondary production step.

The second characteristic composition is a water treatment method in which an organic carbon source is added to perform biological nitrification and denitrification treatment, and crude glycerin produced as a by-product in the primary production process of fatty acid alkyl esters using fats and oils as raw materials. An oil layer separation step of separating an oil layer containing a fatty acid from a waste liquid to take out an aqueous layer containing glycerin, an alcohol separation step of separating a monohydric alcohol from the aqueous layer extracted in the oil layer separation step, and the alcohol. The crude glycerin waste liquid includes a denitrification treatment step of adding an aqueous layer from which a monohydric alcohol has been separated in the separation step as an organic carbon source of the biological nitrification denitrification treatment, and a pre-stage of the oil layer separation step. A fatty acid alkyl ester for producing a fatty acid alkyl ester from an oil layer separated in the oil layer separation step and a monohydric alcohol separated in the alcohol separation step by an acid catalyst method. The point is that the crude glycerin waste liquid produced as a by-product in the secondary production step is supplied to the neutralization treatment step.

When the alkaline catalyst method or the like is used in the primary manufacturing step, it is necessary to carry out a neutralization treatment step for neutralizing the crude glycerin waste liquid before the oil layer separation step. In such a case, if the acid catalyst method is used in the secondary production process for producing the fatty acid alkyl ester, the acidic crude glycerin waste liquid produced as a by-product in the secondary production process can be used as a neutralizing agent required for the neutralization treatment process. Since it can be used, the amount of a neutralizing agent such as hydrochloric acid added in the neutralization treatment step can be reduced.

In addition to the above-mentioned first or second characteristic composition, the third characteristic composition is a predetermined concentration of methanol and COD used as an organic carbon source for biological nitrification and denitrification treatment using a heterotrophic microorganism. The point is that a dilution step of diluting the aqueous layer from which the monohydric alcohol is separated in the alcohol separation step is further included so that the indexes have the same value.

By executing the dilution step, an aqueous layer in which a monohydric alcohol is separated as a denitrifying agent exhibiting denitrifying performance equivalent to that of methanol having a predetermined concentration, for example, 50%, which has been conventionally used as an organic carbon source, is formed. It will be used effectively.

The first characteristic configuration of the water treatment system according to the present invention is a water treatment system including a fuel production apparatus for fatty acid alkyl esters using fats and oils as a raw material, and including treatment of crude glycerin waste liquid produced as a by-product in the fuel production apparatus. An oil layer separating device that separates an oil layer containing fatty acids from the crude glycerin waste liquid produced as a by-product in the fuel production device to take out an aqueous layer containing glycerin, and an oil layer separating device that takes out an aqueous layer containing glycerin, and 1 from the aqueous layer taken out by the oil layer separating device. An alcohol separator for separating valent alcohol and the aqueous layer from which the monovalent alcohol was separated by the alcohol separator are added as an organic carbon source for bionitrification and denitrification treatment using a dependent nutrient microorganism. to the denitrification treatment apparatus, only containing an acid catalyst method excluding alkali catalyst method and a monovalent alcohol is separated from the separated oil layer wherein the alcohol separation unit in the oil layer separator, alkali catalyst method, a biological A secondary production device for biodiesel fuel for producing biodiesel fuel by using any of a catalyst method, an ion exchange resin method, a supercritical method, a subcritical method, and a solid catalyst method is provided, and the secondary production device is provided. The crude glycerin waste liquid produced as a by-product is configured to include a glycerin waste liquid supply path for being supplied to the oil layer separation device .

The second characteristic configuration is a water treatment system including a fuel production device for fatty acid alkyl esters using fats and oils as a raw material, and including treatment of crude glycerin waste liquid produced as a by-product in the fuel production device. An oil layer separating device that separates an oil layer containing a fatty acid from the crude glycerin waste liquid produced as a by-product in the above and takes out an aqueous layer containing glycerin, and a monohydric alcohol is separated from the aqueous layer taken out by the oil layer separating device. An alcohol separation device and a denitrification treatment device in which the aqueous layer from which monovalent alcohol is separated by the alcohol separation device is added as an organic carbon source for biological nitrification and denitrification treatment using dependent nutrient microorganisms. , And a neutralizing treatment device for neutralizing the crude glycerin waste liquid is provided in front of the oil layer separating device, and the oil layer separated by the oil layer separating device and the monovalent alcohol separated by the alcohol separating device A secondary production device for a fatty acid alkyl ester that produces a fatty acid alkyl ester using an acid catalyst method from the above, and a glycerin waste liquid supply route in which the crude glycerin waste liquid produced as a by-product in the secondary production device is supplied to the neutralization treatment device. It is in the point that it is configured with.

In the third characteristic composition, in addition to the above-mentioned first or second characteristic composition, the COD index becomes the same value as the predetermined concentration of methanol used as the organic carbon source of the biological nitrification denitrification treatment. As described above, the point is that the methanol separating device is provided with a diluting device for diluting the aqueous layer from which methanol is separated.

The first characterizing feature of the method for producing de窒剤according to the present invention is a de-窒剤method for producing a produced from the crude glycerol liquid waste containing impurities such as fatty acids, fatty acid alkyl esters to the oil as a raw material An oil layer separation step in which an oil layer containing a fatty acid is separated from a crude glycerin waste liquid produced as a by-product in the primary production step to extract an aqueous layer containing glycerin, and a monohydric alcohol from the aqueous layer extracted in the oil layer separation step. the aqueous layer containing the glycerol separates, and alcohol separation step of taking as an organic carbon source in a biological nitrification and denitrification treatment using heterotrophic microorganisms, only containing, separated by the oil layer separating step Acid catalyst method, acid alkali catalyst method, biocatalyst method, ion exchange resin method, supercritical method, subcritical method, solid catalyst method excluding the alkali catalyst method from the oil layer and the monohydric alcohol separated in the alcohol separation step. A secondary production step of the fatty acid alkyl ester for producing the fatty acid alkyl ester by using any of the above methods is provided, and the crude glycerin waste liquid produced as a by-product in the secondary production step is supplied to the oil layer separation step. It is in the point that it is done.

The second characteristic composition is a method for producing a denitrifying agent produced from a crude glycerin waste liquid containing impurities such as fatty acids, which is a crude glycerin produced as a by-product in the primary production process of a fatty acid alkyl ester made from fats and oils. An oil layer separation step of separating an oil layer containing fatty acids from the waste liquid to extract an aqueous layer containing glycerin, and an aqueous layer containing glycerin by separating a monohydric alcohol from the aqueous layer extracted in the oil layer separation step. , A neutralization treatment step for neutralizing the crude glycerin waste liquid , which comprises an alcohol separation step for taking out as an organic carbon source for biological nitrification and denitrification treatment using a dependent nutrient microorganism, and a step before the oil layer separation step. A secondary production step of a fatty acid alkyl ester for producing a fatty acid alkyl ester from the oil layer separated in the oil layer separation step and the monovalent alcohol separated in the alcohol separation step by using an acid catalyst method. The point is that the crude glycerin waste liquid produced as a by-product in the secondary production step is supplied to the neutralization treatment step.

When the alkaline catalyst method or the like is used in the primary manufacturing process, it is necessary to provide a neutralization treatment device for neutralizing the crude glycerin waste liquid in front of the oil layer separation device. In such a case, if the acid catalyst method is used in the secondary production equipment for producing the fatty acid alkyl ester, the acidic crude glycerin waste liquid produced as a by-product in the secondary production equipment can be used as a neutralizing agent required for the neutralization treatment equipment. Since it can be used, the amount of a neutralizing agent such as hydrochloric acid charged in the neutralizing treatment device can be reduced.

The third feature structure, the first upper mentioned in addition to the third one characteristic feature of the methanol and COD indicator having a predetermined concentration to be used as organic carbon source of the biological nitrification denitrification treatment equivalent The point is that the alcohol separating device is provided with a diluting device for diluting the aqueous layer from which the monohydric alcohol is separated so as to have the value of.

The first characteristic configuration of the denitrifying agent manufacturing apparatus according to the present invention is a denitrifying agent producing apparatus produced from crude glycerin waste liquid containing impurities such as fatty acids, which is a primary fatty acid alkyl ester made from fats and oils. An oil layer separation device that separates an oil layer containing fatty acids from the crude glycerin waste liquid produced as a by-product in the manufacturing equipment to take out an aqueous layer containing glycerin, and a monovalent alcohol are separated from the aqueous layer taken out by the oil layer separation device. the aqueous layer containing the glycerine and, with an alcohol separation unit is taken out as an organic carbon source in a biological nitrification and denitrification treatment using heterotrophic microorganisms, only containing, separated by the oil layer separator oil layer Any of the acid catalyst method, the acid alkali catalyst method, the biocatalyst method, the ion exchange resin method, the supercritical method, the subcritical method, and the solid catalyst method, which remove the alkali catalyst method from the monovalent alcohol separated by the alcohol separator. A secondary production apparatus for a fatty acid alkyl ester for producing a fatty acid alkyl ester using the above method is provided, and a glycerin waste liquid supply route in which the crude glycerin waste liquid produced as a by-product in the secondary production apparatus is supplied to the oil layer separation apparatus is provided. It is in the point that it is configured in preparation.

The second characteristic composition is a production device for a denitrifying agent produced from a crude glycerin waste liquid containing impurities such as fatty acids, and the crude glycerin produced as a by-product in a primary production device for a fatty acid alkyl ester made from fats and oils. An oil layer separating device that separates an oil layer containing fatty acids from the waste liquid to extract an aqueous layer containing glycerin, and an aqueous layer containing glycerin by separating a monovalent alcohol from the aqueous layer extracted by the oil layer separating device. A neutralization treatment device that neutralizes the crude glycerin waste liquid in front of the oil layer separation device , which includes an alcohol separation device that is taken out as an organic carbon source for biological nitrification and denitrification treatment using dependent nutrient microorganisms. A secondary production device for a fatty acid alkyl ester for producing a fatty acid alkyl ester from the oil layer separated by the oil layer separation device and the monovalent alcohol separated by the alcohol separation device by using an acid catalyst method. The crude glycerin waste liquid produced as a by-product in the secondary production apparatus is configured to include a glycerin waste liquid supply path for being supplied to the neutralization treatment apparatus.

In the third characteristic composition, in addition to the above-mentioned first or second characteristic composition, the COD index becomes the same value as the predetermined concentration of methanol used as the organic carbon source of the biological nitrification denitrification treatment. As described above, a diluting device for diluting the aqueous layer from which the monohydric alcohol is separated by the alcohol separating device is further included.

As described above, according to the present invention, a water treatment method, a water treatment system, a denitrifying agent manufacturing method, and a denitrifying agent manufacturing that can suppress greenhouse gas emissions and use existing equipment as they are. It has become possible to provide equipment.

Explanatory drawing of manufacturing method of fatty acid alkyl ester used as biodiesel fuel Explanatory drawing of manufacturing method of denitrifying agent by this invention Explanatory drawing of biological nitrification denitrification treatment Explanatory drawing of water treatment system and denitrifying agent manufacturing equipment Explanatory drawing of alcohol separator Characteristic diagram of flash point of monovalent alcohol-mixed glycerin solution Explanatory drawing of manufacturing method of denitrifying agent which shows another embodiment

Hereinafter, embodiments of a water treatment method, a water treatment system, a denitrifying agent manufacturing method, and a denitrifying agent manufacturing apparatus according to the present invention will be described.

As shown in FIG. 1, in the production process of the fatty acid alkyl ester used as a biodiesel fuel, a fat or oil (raw material fat or oil) such as vegetable oil as a raw material in a reaction tank, a monovalent alcohol such as methanol, and an alkali catalyst are used. A transesterification reaction step in which sodium hydroxide is added to cause a transesterification reaction, a separation step of separating crude glycerin waste liquid from a fatty acid alkyl ester obtained by the transesterification reaction, and a washing step of washing the obtained fatty acid alkyl ester with warm water. Biodiesel fuel is obtained through a cleaning process. In FIG. 1, the primary production process and the primary separation process are described in parentheses, but the notation is for facilitating the distinction from the secondary production process of the fatty acid alkyl ester described later.

Vegetable oil has characteristics such as high viscosity, and when it is used as it is as a fuel for diesel vehicles, there is a risk that precipitates will adhere to the fuel pump and cause a malfunction in the engine. Therefore, it is converted into a fatty acid alkyl ester that can be used as a biodiesel fuel by removing glycerin after subjecting the raw material fat and oil to a chemical treatment such as alkyl esterification.

The raw material 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, as well as tallow and edible waste oils such as fish oil, pork fat and cow pig. So-called tempura oil, etc.) can be exemplified. Further, as the monohydric alcohol, ethanol, propanol and the like can be exemplified in addition to methanol.

By the way, in the above-mentioned production process of biodiesel fuel, crude alkaline glycerin of about 15 to 30% (theoretical value is 10)% of the raw material fat and oil is produced as a by-product together with the fatty acid alkyl ester to be a product.

The by-produced crude glycerin has a high concentration, but contains impurities such as monohydric alcohol, water, water-soluble impurities, catalysts, and unconverted fatty acids. Therefore, when it is used as a raw material for pharmaceuticals, cosmetics, soaps, etc. Since this must be purified and requires a great deal of cost, it has almost no utility value as glycerin and has been difficult to process in the past.

However, in a water treatment facility having a biological denitrification step such as a urine treatment plant, it can be used as a denitrification agent without any problem. Therefore, the crude glycerin waste liquid produced as a by-product in the production process of fatty acid alkyl ester using vegetable oil as a raw material is treated and used as a denitrifying agent.

Hereinafter, a method for producing a denitrifying agent from an alkaline crude glycerin waste liquid containing impurities such as fatty acids and a denitrifying agent according to the present invention will be described, taking as an example the case of producing a fatty acid methyl ester using methanol as a monohydric alcohol. The water treatment method used will be described.

As shown in FIG. 2, in the method for producing the denitrifying agent, an acid is added to the crude glycerin waste liquid produced as a by-product in the primary production process of the fatty acid methyl ester used as a biodiesel fuel using vegetable oil as a raw material, and the mixture is stirred. , A neutralization treatment step that separates an oil layer containing fatty acids and an aqueous layer containing glycerin, an oil layer separation step that takes out the aqueous layer from the crude glycerin waste liquid separated into the oil layer and the aqueous layer in the neutralization treatment step, and oil layer separation. It includes a methanol separation step as an alcohol separation step for separating methanol, which is a monohydric alcohol, from the aqueous layer taken out in the step. Further, it is more preferable to include a dilution step of diluting the aqueous layer from which methanol is separated, that is, the glycerin solution in the methanol separation step.

The water treatment method includes a denitrification treatment step in which the glycerin solution diluted in the dilution step is added as an organic carbon source for the biological nitrification denitrification treatment.

In the neutralization treatment step, crude glycerin waste liquid is extracted from the reaction tank in the primary production step of fatty acid methyl ester adopting the alkali catalyst method and stored in the neutralization treatment tank, and hydrochloric acid is added to the neutralization treatment tank to add raw material fats and oils. Neutralize. The acid used for neutralization is not limited to an inorganic acid such as hydrochloric acid or sulfuric acid, and an organic acid such as acetic acid or lactic acid, carbon dioxide gas or the like can be preferably exemplified. Further, since the crude glycerin waste liquid produced by the acid catalyst method described later is acidic, it can be neutralized by appropriately mixing it.

In the neutralization treatment step, the waste liquid is neutralized by adding hydrochloric acid to the alkaline crude glycerin waste liquid that is in an emulsion state, and the waste liquid is neutralized into an oil layer containing fatty acids and an aqueous layer containing glycerin, salts, etc. Be separated.

In the oil layer separation step, the oil layer containing unreacted fats and oils and fatty acid methyl ester is separated into the upper part of the neutralization treatment tank, and the aqueous layer containing crude glycerin is separated into the lower part of the neutralization treatment tank. After a lapse of a predetermined time, the valve provided at the bottom of the neutralization treatment tank is opened, and the aqueous layer containing the crude glycerin separated at the bottom is discharged, so that the aqueous layer is taken out from the crude glycerin waste liquid separated into the oil layer and the aqueous layer. Is done.

The oil layer separation step may be configured to separate the oil layer and the aqueous layer using a centrifuge or a filtration membrane.

The methanol separation step is a step of separating and removing methanol that did not contribute to the transesterification reaction step from the aqueous layer containing glycerin. Methanol obtained by heating a liquid containing glycerin filled in a reaction tank to about 60 ° C. and evaporating it. After that, a vacuum distillation method is adopted in which the pressure is reduced and recovered.

In the methanol separation step, a gas-liquid contact method, a membrane separation method, an ion exchange method, or the like can be used in addition to the vacuum distillation method. A spray-drying method can be preferably used as the gas-liquid contact method, which is a method in which a liquid containing crude glycerin is discharged in the form of a spray and brought into contact with warm air, and methanol having a low boiling point is transferred to the air side for separation. be. The membrane separation method is a method using a membrane that preferentially permeates methanol. The ion exchange method is a method for separating methanol by utilizing the adsorption characteristics of an ion exchange resin.

In the above-mentioned neutralization treatment tank, an oil layer separated into an oil layer and an aqueous layer in the neutralization treatment step and a crude glycerin waste liquid separated in the oil layer separation step remains. Since this oil layer contains a high concentration of fatty acids, it can be circulated and supplied to the primary production process of fatty acid methyl ester using an alkali catalytic method as a raw material.

However, the oil layer separated in the oil layer separation step contains a large amount of fats and oils having high acid value such as free fatty acids, and the purity of methanol separated in the methanol separation step is not so high, so all of them are in the same state. Even if the alkaline catalyst method is used, it may be difficult to efficiently produce the fatty acid methyl ester.

Even in such a case, it is possible to efficiently recycle the fatty acid methyl ester used in the biodiesel fuel by executing the secondary production process using a method other than the alkaline catalyst method. The crude glycerin effluent produced as a by-product in the secondary production step is separated from the fatty acid methyl ester in the secondary separation step and then supplied to the oil layer separation step described above to separate the oil layer and methanol before biological nitrification. It will be added as an organic carbon source for denitrification treatment.

As the secondary production process, an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method, a solid catalyst method, etc. can be adopted. Even high waste cooking oils and / or fats and oils can be transesterified with alcohols such as methanol.

It is particularly preferable to use the acid catalyst method as the secondary production process.
As shown in FIG. 7, the fatty acid methyl ester secondaryly produced by the acid catalyst method in the secondary production step is separated into a crude glycerin waste liquid and a fatty acid methyl ester in the secondary separation step, and the separated fatty acid methyl ester is removed. Fatty acid methyl ester neutralization treatment and dehydration and dehydration by performing a neutralization / dehydration step in which the crude glycerin waste liquid treated with methanol is charged from the lower part of the tank and brought into contact with each other and overflowed from the upper part using the difference in specific gravity. Demethane treatment can be performed at the same time. As a result, water and methanol are absorbed by the crude glycerin effluent, resulting in a high quality fatty acid methyl ester from which water and methanol have been removed. In addition, the crude glycerin waste liquid that has absorbed water and methanol is sent to the neutralization treatment step.

It is more preferable to adopt the biocatalyst method as the secondary manufacturing process. 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 biocatalytic 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. It is also possible to utilize the oil layer separated in the oil layer separation step as a compost material without using it for the synthesis of fatty acid methyl ester.

Even low-purity methanol separated in the methanol separation step can be reused as a monohydric alcohol in the primary manufacturing process using the alkali catalyst method by repeating the distillation treatment to increase the purity. Is.

Here, the denitrification treatment step will be described.
As shown in FIG. 3, in the urine treatment plant, a biological nitrification denitrification method using a heterotrophic microorganism such as a circulation denitrification method is adopted for treating nitrogen-containing organic wastewater. The nitrification denitrification method includes a nitrification step in which ammonia nitrogen in the water to be treated is oxidized to nitrite nitrogen by ammonia-oxidizing bacteria, and nitrite nitrogen is further oxidized to nitrate nitrogen by nitrite-oxidizing bacteria, and nitrite. This is a method of decomposing ammonia nitrogen in the water to be treated into nitrogen gas through a denitrification treatment step of decomposing nitrogen and nitrate nitrogen into nitrogen gas by a dependent nutrient denitrifying bacterium. The nitrifying liquid in the nitrification step is circulated and supplied to the denitrification treatment step.

As a substitute for methanol in such a denitrification treatment step, the crude glycerin liquid (aqueous layer) taken out in the oil layer separation step of the above-mentioned crude glycerin waste liquid treatment method is used as an organism using a heterotrophic microorganism. It is added as an organic carbon source for bionitrification and denitrification treatment.

Since the aqueous layer containing the glycerin, salt, etc. is decomposed in a short time as an organic carbon source for biological nitrification and denitrification treatment using a heterotrophic microorganism, organic pollutants are unlikely to remain.

In this way, instead of adding a large amount of methanol or the like as an organic carbon source in the denitrification treatment step of the biological nitrification denitrification method, crude glycerin produced as a by-product in the fatty acid methyl ester production step is effectively used. The chemical cost of methanol can be reduced, and the emission of greenhouse gases due to the absence of methanol derived from fossil fuels can be suppressed.

By the way, according to the provisions of the Fire Service Act, products that do not contain components other than alcohol and water and have an alcohol content of 60% or more are classified as Dangerous Goods Class 4 (flammable liquid) alcohols. Structures such as storage facilities are subject to regulations to ensure safety. However, the alcohol content of methanol used as a denitrifying agent is adjusted to about 50% so that it can be treated as a non-dangerous substance, and the storage facility is constructed without being restricted by the regulations. ..

The glycerin liquid (aqueous layer) that has undergone the above-mentioned oil layer separation step corresponds to the third petroleum class of the dangerous goods class 4 (flammable liquid) because the glycerin is a trihydric alcohol. Since methanol that did not contribute to the transesterification reaction remains in the glycerin solution (aqueous layer), it becomes a designated combustible substance when the capacity becomes 2000 L or more. In this case, if the storage capacity is less than 2000 L, the existing storage facility for methanol can be used as it is, but if the capacity is 2000 L or more, it is subject to regulation as a designated combustible material, and the existing storage facility for methanol is subject to regulation. The storage facility cannot be used as it is.

However, the crude glycerin waste liquid after executing the above-mentioned methanol separation step is judged to be a non-dangerous substance because it has no flash point even if it is a Class 4 flammable liquid specified in the Fire Service Act, and its capacity is 2000 L or more. Even so, the existing storage facility for methanol can be used as it is.

The glycerin solution (aqueous layer) obtained in the above-mentioned methanol separation step can be used as it is as a denitrifying agent, but as an organic carbon source for biological nitrification and denitrification treatment using a dependent vegetative microorganism. It is preferable to carry out a diluting step of diluting the aqueous layer from which methanol has been separated in the methanol separation step so that the value of the COD index becomes equivalent to that of the predetermined concentration of methanol used.

This is because by executing the dilution step, waste glycerin can be effectively used as a denitrifying agent that exhibits denitrifying performance equivalent to that of methanol having a predetermined concentration conventionally used as an organic carbon source.

COD is an index expressing the amount of organic matter in water as "oxygen consumption when decomposed by an oxidizing agent", and there are a plurality of types depending on the type of oxidizing agent used and the reaction conditions. In the present invention, "COD _Cr " using potassium dichromate as an oxidizing agent can be preferably used as a COD index. _{This is because "COD Mn} ", which uses potassium permanganate as an oxidizing agent, has a low capture rate with respect to the actual amount of organic matter.

As described above, it is a method for producing a denitrifying agent produced from a crude glycerin waste liquid containing impurities such as fatty acids, from the crude glycerin waste liquid produced as a by-product in the primary production process of a fatty acid alkyl ester using fats and oils as a raw material. The oil layer separation step of separating the oil layer containing fatty acids to extract the aqueous layer containing glycerin and the aqueous layer containing glycerin by separating the monohydric alcohol from the aqueous layer extracted in the oil layer separation step are dependent nutrients. A method for producing a denitrifying agent can be realized, which includes an alcohol separation step of extracting as an organic carbon source for biological nitrification and denitrification treatment using a sex microorganism.

The denitrifying agent is produced by an acid catalyst method, an acid alkali catalyst method, or a biocatalyst method, which excludes an alkali catalyst method from an oil layer separated in an oil layer separation step and a monovalent alcohol separated in an alcohol separation step. , A secondary production process of a fatty acid alkyl ester for producing a fatty acid alkyl ester using any of an ion exchange resin method, a supercritical method, a subcritical method, and a solid catalyst method, which is produced as a by-product in the secondary production process. The crude glycerin waste liquid is configured to be supplied to the oil layer separation step via the glycerin waste liquid supply route.

Further, in the method for producing the denitrifying agent, monohydric alcohol is used in the alcohol separation step so that the COD index becomes the same as that of methanol having a predetermined concentration used as an organic carbon source in the biological nitrification denitrification treatment. It further comprises a dilution step of diluting the separated aqueous layer.

Hereinafter, a water treatment system including a treatment of crude glycerin waste liquid produced as a by-product in the production process of fatty acid methyl ester using fats and oils as a raw material according to the present invention and an apparatus for producing a denitrifying agent will be described.

As shown in FIG. 4, the water treatment system includes a fatty acid methyl ester production facility 10 which is an example of a fatty acid alkyl ester production facility, and a water treatment facility 20. The fatty acid methyl ester production facility 10 includes a fatty acid methyl ester production device 11 and a cleaning device 12, and the water treatment facility 20 includes an oil layer separation device 13, a methanol separation device 14 as an alcohol separation device, and biological equipment. A biological treatment device including a denitrification treatment device 22 for performing a nitrification denitrification treatment, a nitrification device 23, and a denitrification agent storage tank 21 is provided. Then, a fatty acid methyl ester production facility 10 and a part of the water treatment facility 20 constitute a denitrifying agent production apparatus.

Waste fats and oils as raw materials, methanol, and sodium hydroxide as an alkali catalyst are charged into the reaction tank 11a provided in the primary production apparatus 11 for fatty acid methyl ester, the transesterification reaction step is executed, and the fatty acid obtained by the transesterification reaction is executed. A primary separation step is performed to separate the crude glycerin effluent from the methyl ester.

The fatty acid methyl ester taken out from the reaction tank 11a is washed with warm water in the washing device 12 and taken out as the fatty acid methyl ester. Further, the crude glycerin waste liquid discharged from the reaction tank 11a and the cleaning waste liquid discharged from the cleaning device 12 are put into the oil / fat separation tank provided in the oil layer separation device 13 and neutralized with hydrochloric acid as a neutralizing agent. It is separated into an oil layer and an aqueous layer. Alternatively, as shown by the alternate long and short dash line in FIG. 4, sweet water from the soap factory may be put into the oil / fat separation tank.

After a certain period of time, the lower aqueous layer is withdrawn and supplied to the methanol separator 14, and after the methanol is removed, it is supplied to the diluting device 15, diluted to a predetermined concentration, and then denitrified agent storage tank. It is stored in 21.

Since the cleaning waste liquid discharged from the cleaning device 12 has a large amount of water and it is difficult to remove alcohol with the methanol separation device 14, the cleaning waste liquid is not neutralized together with the crude glycerin waste liquid, but is separately neutralized and separated into oil layers. It is preferable to carry out the treatment and use it as diluting water in the diluting device 15 without performing the methanol separation treatment.

The methanol separator 14, the diluter, and the denitrifier storage tank 21 do not need to be installed on the same site, and the denitrifier, which is a glycerin solution (aqueous layer) from which methanol is separated by the methanol separator 14, is mounted on the vehicle. It may be mounted on a tank and transported to a denitrifying agent storage tank 21 at a distance.

After diluting with the diluting device 14, it may be mounted on the vehicle-mounted tank, or if the diluting device 14 is installed adjacent to the denitrifying agent storage tank 21, the glycerin solution (aqueous layer) before dilution is mounted on the vehicle-mounted tank. The denitrifying agent storage tank 21 may be filled after being diluted by the diluting device 14 at the transport destination. In the latter case, the transportation cost can be reduced.

As shown by the broken line in FIG. 4, in the fatty acid methyl ester production facility 10, in addition to the reaction tank 11a for producing the fatty acid methyl ester by the alkali catalytic method, the fat and oil components separated by the oil layer separation device 13 and the methanol separation device 14 A second reaction tank 11b is provided as a secondary production apparatus for fatty acid methyl ester, which produces fatty acid methyl ester by a method other than the alkali catalytic method using the methanol separated in 1.

That is, the device for producing a denitrifying agent according to the present invention contains glycerin by separating an oil layer containing a fatty acid from a crude glycerin waste liquid produced as a by-product in the device for producing a fatty acid alkyl (methyl) ester made from fats and oils. The oil layer separating device 13 for extracting the aqueous layer and the aqueous layer containing glycerin by separating the monohydric alcohol from the aqueous layer taken out by the oil layer separating device 13 are bionitrified and denitrified using a dependent microbial microorganism. It is provided with an alcohol separating device 14 that is taken out as an organic carbon source for nitrogen treatment.

Further, the acid catalyst method, the acid alkali catalyst method, the biocatalyst method, the ion exchange resin method, and the super Fatty acid alkyl (methyl) ester production in the second reaction tank 11b, which is a secondary production apparatus for fatty acid alkyl (methyl) ester, which produces fatty acid alkyl ester using any of the critical method, subcritical method, and solid catalyst method. In preparation for the equipment 10, the crude glycerin effluent produced as a by-product in the secondary production apparatus is configured to be supplied to the oil layer separation apparatus 13 via the glycerin effluent supply path 11c.

A neutralization treatment device for neutralizing the crude glycerin waste liquid is provided in front of the oil layer separation device 13, and an acid catalyst is provided from the oil layer separated by the oil layer separation device 13 and the monohydric alcohol separated by the alcohol separation device 14. The fatty acid alkyl (methyl) ester secondary production apparatus for producing the fatty acid alkyl (methyl) ester using the method is provided in the fatty acid alkyl (methyl) ester production facility 10, and the crude glycerin waste liquid produced as a by-product in the secondary production apparatus is generated. It is configured to be supplied to the neutralization treatment apparatus via the glycerin waste liquid supply path 11c.

Further, the alcohol separator 13 dilutes the aqueous layer from which the monohydric alcohol has been separated so that the COD index becomes the same as that of methanol having a predetermined concentration used as the organic carbon source of the biological nitrification denitrification treatment 22. It is further equipped with a diluting device.

As shown in FIG. 5, in the methanol separation device 14 adopting the vacuum distillation method, the reaction tank 14a into which the glycerin solution (aqueous layer) from which the fats and oils have been separated by the oil layer separation device 13 is charged, and the separated methanol is recovered. It is provided with methanol recovery tanks 14f, 14g, 14h, and a storage tank 14c for storing a glycerin solution (aqueous layer) from which methanol has been separated.

A heat exchanger 14b using oil as a heat medium is arranged in the reaction tank 14a and heated to about 60 ° C. The methanol vaporized in the reaction tank 14a is guided to the capacitors 14d and 14e sucked under reduced pressure by the vacuum pump P3 to be cooled, transiently recovered in the methanol recovery tanks 14f and 14g, and then recovered in the methanol recovery tanks 14f and 14g by the pumps P1 and P2. It is collected in 14h. In FIG. 5, reference numeral 14i is a separation cylinder for collecting foreign matter. The glycerin waste liquid in which methanol is vaporized is then pumped to the storage tank 14c by the pump P4.

For example, the glycerin solution (aqueous layer) having a methanol concentration of 5 to 15 wt% charged into the reaction tank 14a is distilled under reduced pressure and recovered as a glycerin solution (aqueous layer) having a methanol concentration of 0 to 2 wt% in the storage tank 14c.

An experimental example of the alcohol separation step will be described below.
The glycerin concentration of the denitrifying agent produced from the crude glycerin waste liquid produced as a by-product in the fatty acid methyl ester production process shows a value of about 25 wt%. Therefore, pure methanol was added to the pure glycerin solution having a glycerin concentration of 25 wt% to generate each methanol mixed glycerin solution having a methanol concentration of 3,4,5,6,8 wt%, and the Ebel closed automatic flash point. The presence or absence of ignition was confirmed using a tester (manufactured by Tanaka Scientific Instruments Manufacturing Co., Ltd.).

The measurement result is shown in FIG. It was confirmed that when the methanol concentration contained in the pure glycerin solution having a glycerin concentration of 25 wt% was 4, 5, 6, 8 wt%, it ignited at 80 ° C. or lower, respectively, but when it reached 3 wt%, the measuring instrument was used. The flash point could not be detected.

Therefore, it was confirmed that by adjusting the methanol concentration to 3 wt% or less, more preferably 2 wt% or less with the methanol separator 14, even a Class 4 flammable liquid specified in the Fire Service Act can be treated as a non-dangerous substance. Was done.

The embodiment of the present invention has been described above by taking the case where methanol is used as the monohydric alcohol as an example. However, a method for producing a denitrifying agent from an alkaline crude glycerin waste liquid containing impurities such as fatty acids and denitrification according to the present invention. Needless to say, the water treatment method using an agent can be applied even when an alcohol other than methanol is used as the monohydric alcohol.

10: Fatty acid alkyl ester manufacturing equipment (fatty acid methyl ester manufacturing equipment)
11: Fatty acid methyl ester production apparatus 11a: Reaction tank 11b: Secondary reaction vessel (secondary production apparatus)
11c: Glycerin waste liquid supply path 12: Washing tank 13: Oil layer separation device 14: 1-valent alcohol separation device (methanol separation device)
15: Diluting device 20: Water treatment equipment 21: Denitrifying agent storage tank 22: Denitrifying treatment device 23: Nitrification device

Claims (12)

A water treatment method in which an organic carbon source is added to perform biological nitrification and denitrification treatment.
An oil layer separation step that separates an oil layer containing fatty acids from the crude glycerin waste liquid produced as a by-product in the primary production process of fatty acid alkyl esters using fats and oils as a raw material and extracts an aqueous layer containing glycerin.
An alcohol separation step of separating a monohydric alcohol from the aqueous layer taken out in the oil layer separation step, and an alcohol separation step.
A denitrification treatment step in which an aqueous layer from which a monohydric alcohol is separated in the alcohol separation step is added as an organic carbon source for the biological nitrification denitrification treatment, and a denitrification treatment step.
Only including,
Acid catalyst method, acid alkali catalyst method, biocatalyst method, ion exchange resin method, supercritical method for removing the alkali catalyst method from the oil layer separated in the oil layer separation step and the monohydric alcohol separated in the alcohol separation step. A secondary production step of a fatty acid alkyl ester for producing a fatty acid alkyl ester using any of the subcritical method and the solid catalyst method is provided, and the crude glycerin waste liquid produced as a by-product in the secondary production step separates the oil layer. A water treatment method that is configured to be supplied to the process. A water treatment method in which an organic carbon source is added to perform biological nitrification and denitrification treatment.
An oil layer separation step that separates an oil layer containing fatty acids from the crude glycerin waste liquid produced as a by-product in the primary production process of fatty acid alkyl esters using fats and oils as a raw material and extracts an aqueous layer containing glycerin.
An alcohol separation step of separating a monohydric alcohol from the aqueous layer taken out in the oil layer separation step, and an alcohol separation step.
A denitrification treatment step in which an aqueous layer from which a monohydric alcohol is separated in the alcohol separation step is added as an organic carbon source for the biological nitrification denitrification treatment, and a denitrification treatment step.
Including
A neutralization treatment step for neutralizing the crude glycerin waste liquid is provided before the oil layer separation step.
A secondary production step of a fatty acid alkyl ester for producing a fatty acid alkyl ester from an oil layer separated in the oil layer separation step and a monohydric alcohol separated in the alcohol separation step by an acid catalyst method is provided.
A water treatment method configured such that crude glycerin waste liquid produced as a by-product in the secondary production step is supplied to the neutralization treatment step. The monohydric alcohol is separated in the alcohol separation step so that the COD index becomes equivalent to that of methanol having a predetermined concentration used as an organic carbon source for biological nitrification and denitrification treatment using a dependent vegetative microorganism. The water treatment method according to claim 1 or 2 , further comprising a diluting step of diluting the aqueous layer. A water treatment system equipped with a fuel production device for fatty acid alkyl esters made from fats and oils, and including treatment of crude glycerin waste liquid produced as a by-product in the fuel production device.
An oil layer separating device that separates an oil layer containing fatty acids from the crude glycerin waste liquid produced as a by-product in the fuel manufacturing device and extracts an aqueous layer containing glycerin.
An alcohol separator that separates monovalent alcohol from the aqueous layer taken out by the oil layer separator, and an alcohol separator.
A denitrification treatment device for adding the aqueous layer from which a monohydric alcohol has been separated by the alcohol separation device as an organic carbon source for biological nitrification denitrification treatment using a heterotrophic microorganism.
Only including,
Acid catalyst method, acid alkali catalyst method, biocatalyst method, ion exchange resin method, supercritical method for removing the alkali catalyst method from the oil layer separated by the oil layer separation device and the monohydric alcohol separated by the alcohol separation device. A biodiesel fuel secondary production apparatus for producing biodiesel fuel using any of the subcritical method and the solid catalyst method is provided, and the crude glycerin waste liquid produced as a by-product in the secondary production apparatus separates the oil layer. A water treatment system configured with a glycerin effluent supply path supplied to the device. A water treatment system equipped with a fuel production device for fatty acid alkyl esters made from fats and oils, and including treatment of crude glycerin waste liquid produced as a by-product in the fuel production device.
An oil layer separating device that separates an oil layer containing fatty acids from the crude glycerin waste liquid produced as a by-product in the fuel manufacturing device and extracts an aqueous layer containing glycerin.
An alcohol separator that separates monovalent alcohol from the aqueous layer taken out by the oil layer separator, and an alcohol separator.
A denitrification treatment device for adding the aqueous layer from which a monohydric alcohol has been separated by the alcohol separation device as an organic carbon source for biological nitrification denitrification treatment using a heterotrophic microorganism.
Including
A neutralization treatment device for neutralizing the crude glycerin waste liquid is provided in front of the oil layer separation device.
A secondary production device for a fatty acid alkyl ester for producing a fatty acid alkyl ester from an oil layer separated by the oil layer separation device and a monohydric alcohol separated by the alcohol separation device by an acid catalyst method is provided.
A water treatment system configured to include a glycerin waste liquid supply path in which crude glycerin waste liquid produced as a by-product in the secondary production apparatus is supplied to the neutralization treatment apparatus. Dilution that dilutes the aqueous layer from which the monohydric alcohol has been separated by the alcohol separator so that the COD index is equivalent to that of methanol at a predetermined concentration used as the organic carbon source for the biological nitrification and denitrification treatment. The water treatment system according to claim 4 or 5 , further comprising an apparatus. A method for producing a denitrifying agent produced from a crude glycerin waste liquid containing impurities such as fatty acids.
An oil layer separation step that separates an oil layer containing fatty acids from the crude glycerin waste liquid produced as a by-product in the primary production process of fatty acid alkyl esters using fats and oils as a raw material and extracts an aqueous layer containing glycerin.
Alcohol separation in which monovalent alcohol is separated from the aqueous layer taken out in the oil layer separation step and the aqueous layer containing glycerin is taken out as an organic carbon source for biological nitrification and denitrification treatment using a heterotrophic microorganism. Process and
Only including,
Acid catalyst method, acid alkali catalyst method, biocatalyst method, ion exchange resin method, supercritical method for removing the alkali catalyst method from the oil layer separated in the oil layer separation step and the monohydric alcohol separated in the alcohol separation step. A secondary production step of a fatty acid alkyl ester for producing a fatty acid alkyl ester using any of the subcritical method and the solid catalyst method is provided, and the crude glycerin waste liquid produced as a by-product in the secondary production step separates the oil layer. A method of making a denitrifying agent, which is configured to be supplied to the process. A method for producing a denitrifying agent produced from a crude glycerin waste liquid containing impurities such as fatty acids.
An oil layer separation step that separates an oil layer containing fatty acids from the crude glycerin waste liquid produced as a by-product in the primary production process of fatty acid alkyl esters using fats and oils as a raw material and extracts an aqueous layer containing glycerin.
Alcohol separation in which monovalent alcohol is separated from the aqueous layer taken out in the oil layer separation step and the aqueous layer containing glycerin is taken out as an organic carbon source for biological nitrification and denitrification treatment using a heterotrophic microorganism. Process and
Including
A neutralization treatment step for neutralizing the crude glycerin waste liquid is provided before the oil layer separation step.
A secondary production step of a fatty acid alkyl ester for producing a fatty acid alkyl ester from an oil layer separated in the oil layer separation step and a monohydric alcohol separated in the alcohol separation step by an acid catalyst method is provided.
It said secondary crude glycerin waste liquid in the manufacturing process by-product has been configured to be supplied to the neutralization step, the manufacturing method of de窒剤. Dilution that dilutes the aqueous layer from which the monohydric alcohol was separated in the alcohol separation step so that the COD index is equivalent to that of methanol at a predetermined concentration used as the organic carbon source for the biological nitrification and denitrification treatment. The method for producing a denitrifying agent according to claim 7 or 8 , further comprising a step. A device for producing a denitrifying agent produced from crude glycerin waste liquid containing impurities such as fatty acids.
An oil layer separator that separates an oil layer containing fatty acids from a crude glycerin waste liquid produced as a by-product in a primary production device for fatty acid alkyl esters using fats and oils as a raw material, and extracts an aqueous layer containing glycerin.
Alcohol separation in which monovalent alcohol is separated from the aqueous layer taken out by the oil layer separator and the aqueous layer containing glycerin is taken out as an organic carbon source for biological nitrification and denitrification treatment using a heterotrophic microorganism. Equipment and
Only including,
Acid catalyst method, acid alkali catalyst method, biocatalyst method, ion exchange resin method, supercritical method for removing the alkali catalyst method from the oil layer separated by the oil layer separation device and the monohydric alcohol separated by the alcohol separation device. , A secondary production apparatus for fatty acid alkyl esters for producing fatty acid alkyl esters using any of the subcritical method and the solid catalyst method, and the crude glycerin waste liquid produced as a by-product in the secondary production apparatus separates the oil layer. A denitrifying agent manufacturing device configured with a glycerin effluent supply path supplied to the device. A device for producing a denitrifying agent produced from crude glycerin waste liquid containing impurities such as fatty acids.
An oil layer separator that separates an oil layer containing fatty acids from a crude glycerin waste liquid produced as a by-product in a primary production device for fatty acid alkyl esters using fats and oils as a raw material, and extracts an aqueous layer containing glycerin.
Alcohol separation in which monovalent alcohol is separated from the aqueous layer taken out by the oil layer separator and the aqueous layer containing glycerin is taken out as an organic carbon source for biological nitrification and denitrification treatment using a heterotrophic microorganism. Equipment and
Including
A neutralization treatment device for neutralizing the crude glycerin waste liquid is provided in front of the oil layer separation device.
A secondary production device for a fatty acid alkyl ester for producing a fatty acid alkyl ester from an oil layer separated by the oil layer separation device and a monohydric alcohol separated by the alcohol separation device by an acid catalyst method is provided.
The secondary manufacturing-produced is crude glycerin waste in devices that are configured with a glycerin waste supply path to be supplied to the neutralization apparatus, the manufacturing apparatus of de窒剤. Dilution that dilutes the aqueous layer from which the monohydric alcohol has been separated by the alcohol separator so that the COD index is equivalent to that of methanol at a predetermined concentration used as the organic carbon source for the biological nitrification and denitrification treatment. The device for producing a denitrifying agent according to claim 10 or 11 , further comprising an device.

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