JP2003260448A - Method and apparatus for solubilization treatment of organic waste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for solubilization treatment of an organic waste by which a cost reduction can be achieved and a high efficiency for methane recycling in methane fermentation can be achieved when the solubilization treatment of the organic waste is performed, and an apparatus for solubilization treatment thereof. <P>SOLUTION: The apparatus 1 for the solubilization treatment of the organic waste comprises a solubilization tank 2, an organic waste feeding mechanism 3 for feeding the organic waste into the solubilization tank 2, and a solid alkali agent feeding mechanism 4 for feeding a solid alkali agent 32 into the organic waste 25 on the organic waste feeding mechanism or the organic waste 12 in the solubilization tank 2. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for solubilizing an organic waste and a solubilizing apparatus for the organic waste in a methane fermentation pretreatment of the organic waste.

[Prior art]

In recent years, the problem of waste disposal of industrial waste, household waste, etc. has been highlighted, and in order to reduce the environmental deterioration due to waste dumping, waste recycling technology is drawing attention. Of the above-mentioned various wastes, organic wastes contained in raw garbage and the like have been particularly studied because methane fermentation makes it possible to obtain methane gas. In this methane gasification technology by methane fermentation, it is necessary to solubilize the organic waste, that is, solubilize and solubilize the organic waste, in order to efficiently and inexpensively generate methane gas.

There are the following four conventional solubilization treatment methods. The first method is a method of crushing the organic waste into fine particles by the high pressure applied instantaneously by the compression crusher. In the second method, the microorganisms (thermophilic bacteria) present in the organic waste cause both the oxidative decomposition reaction and the physicochemical thermal denaturation by heat to biologically oxidize the organic waste. It is a method of decomposing and reducing the volume of sludge. Third
The method is a method in which an alkali such as caustic soda or sodium carbonate is added to the organic waste and the microbial cells in the waste are solubilized and crushed by a wet mill treatment. The fourth method is a method of oxidatively decomposing the waste by positively adding an oxidizing agent such as ozone or hydrogen peroxide solution to the organic waste.

[0004]

By the way, in the above-mentioned solubilization treatment method, the first method has a drawback that the equipment cost is increased because a large-scale device called a compression crusher is used. Further, the second method has a drawback that microorganisms are hard to work depending on the organic waste as a raw material, and the methane recovery efficiency in the methane fermentation step is reduced. In addition, the third method has a drawback that it is necessary to spray the organic waste with alkaline water at all times, resulting in an increase in the chemical solution cost. In addition, the fourth method uses a device called an ozone generator, and therefore has a drawback that the equipment cost is increased. In addition, in the third method and the fourth method, when the stirring treatment is performed for homogenizing the pH of the organic waste, carbon components are likely to be lost due to the generation of carbon dioxide gas. The efficiency of methane recovery in this will decrease. Further, depending on various kinds of various raw materials contained in the organic waste, PH variation becomes remarkable, PH control is difficult, and treatment condition setting becomes complicated, resulting in high efficiency of methane fermentation. It was difficult.

The present invention provides a method and apparatus for solubilizing an organic waste, which can reduce the cost when solubilizing the organic waste and can improve the efficiency of methane recovery in methane fermentation. The purpose is to provide.

[0006]

In order to solve the above problems, the present invention proposes the following means. The invention according to claim 1 is a method for solubilizing an organic waste and a solubilizing apparatus for performing a methane fermentation of the organic waste, wherein a solid alkali agent is added to the organic waste to remove the organic waste. It is characterized by solubilizing toxic waste.

According to the method for solubilizing an organic waste according to the present invention, a solid alkaline agent is added to the organic waste, the destruction of the polymer waste and the PH in the organic waste.
Since the decomposition by the bacteria in the gradient proceeds, the solubilization of the organic waste can be promoted.

The invention according to claim 2 is characterized in that, in the method for solubilizing an organic waste according to claim 1, the organic waste is solubilized in an atmosphere at a temperature of 35 ° C. or higher.

According to the organic waste solubilization treatment method of the present invention, it is possible to promote the solubilization of the organic waste suitable for the medium temperature methane fermentation conditions.

The invention according to claim 3 is the method for solubilizing an organic waste according to claim 1 or 2, wherein the organic waste is solubilized in an atmosphere at a temperature of 60 ° C or higher. And

According to the method for solubilizing organic waste according to the present invention, the solubilization of organic waste can be promoted under high temperature conditions.

The invention according to claim 4 is characterized in that, in the method for solubilizing an organic waste according to any one of claims 1 to 3, the object to be treated is heated with steam or hot water. To do.

According to the method for solubilizing the organic waste according to the present invention, it is possible to remove a component which hinders the methane fermentation efficiency of the organic waste, and to achieve high efficiency of methane fermentation.

According to a fifth aspect of the present invention, a solubilization tank, an organic waste supply mechanism for supplying organic waste to the solubilization tank, an organic waste on the organic waste supply mechanism or the above The apparatus for solubilizing an organic waste comprises a solid alkaline agent supply mechanism for supplying a solid alkaline agent to the organic waste in the solubilization tank.

According to the apparatus for solubilizing the organic waste according to the present invention, the solid alkaline agent is added to the organic waste to destroy the polymer waste in the organic waste and to remove P
Since decomposition by bacteria in the H gradient proceeds, solubilization of the organic waste can be promoted.

The invention according to claim 6 is the apparatus for solubilizing an organic waste according to claim 5, further comprising a steam / hot water supply mechanism for supplying steam or hot water to the waste in the solubilization tank. It is characterized by

According to the apparatus for solubilizing the organic waste according to the present invention, it is possible to remove a component which hinders the methane fermentation efficiency of the organic waste, and to achieve high efficiency of methane fermentation.

The invention according to claim 7 is the apparatus for solubilizing the organic waste according to claim 5 or 6,
A crushing stirring mechanism for crushing and stirring the waste is provided in the treatment tank. The crushing stirring mechanism is composed of rotating shafts whose axes are parallel to each other and stirring blades spirally provided on these rotating shafts. It is characterized by

According to the apparatus for solubilizing organic waste according to the present invention, the organic waste supplied with the solid alkaline agent is continuously crushed and stirred by the crushing stirring mechanism. The destruction of the molecular waste and the decomposition by the bacterium progress, and the solubilization of the organic waste can be further promoted.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an organic waste solubilization treatment apparatus according to an embodiment of the present invention,
FIG. 2 is a diagram showing a stirring blade of a crushing stirring mechanism included in the organic waste solubilization treatment device, and FIG. 3 is a lump of the organic waste during the solubilization treatment in the organic waste solubilization treatment device. It is a schematic diagram which shows the PH distribution of.

As shown in FIG. 1, the apparatus 1 for solubilizing an organic waste according to this embodiment includes a solubilization tank 2, an organic waste supply mechanism 3, a solid alkaline agent supply mechanism 4, and The control unit 5 is included as a main component.

The solubilization tank 2 has a plurality of steam / warm water supply mechanisms 7 attached to the wall portion 6, a crushing stirring mechanism 8, an organic waste discharge port 10 attached to the bottom portion 9, and the outside. A covering hot water jacket 11 is provided. The organic waste supply mechanism 3 includes a supply plate 21 and a scraper 22.
The drive mechanism 23 and the hot water jacket 24 are provided below the supply plate 21. Solid alkaline agent supply mechanism 4
A solid alkaline agent storage tank 31 and a solid alkaline agent supply valve 33 are provided in the.

The steam / warm water supply mechanism 7 is for supplying steam / warm water 13 to the organic waste 12 put into the solubilization tank 2, and has a plurality of nozzles 14 provided in the solubilization tank 2.
Is equipped with. The crushing stirring mechanism 8 has two stirring screws 41, 42 provided in parallel with each other as shown in FIG.
It is configured with. Stirring screws 41, 42
Is composed of rotating shafts 43 and 44 and stirring blades 45 and 46. In this case, a constant gap 47 is formed between the stirring screw 41 and the stirring screw 42.
The organic waste discharge port 10 is a discharge port for discharging an organic waste 12 described later. The hot water jacket 11 heats the solubilization tank 2 by setting the temperature of the control unit 5.

The supply plate 21 has an inclined surface on which the organic waste 25 is mounted. The drive mechanism 23 applies power to the scraper 22 and inputs the organic waste 25 into the solubilization tank 2. The scraper 22 pushes out the organic waste 25 and puts it into the solubilization tank 2, and is driven by the drive mechanism 23. The hot water jacket 24 heats the supply plate 21 by setting the temperature of the control unit 5.

A solid alkaline agent 32 is stored in the solid alkaline agent storage tank 31.
2 is that the solid alkaline agent supply valve 33 opens,
It is adapted to be put into the solubilization tank 2. The above-mentioned respective elements are controlled by the control unit 5 so that the organic waste 12 can be solubilized automatically.

Next, a method of solubilizing the organic waste by the solubilization processing apparatus 1 will be described. When the solubilization processing apparatus 1 is started, the supply plate 21 and the solubilization tank 2
Is heated by the hot water jackets 11 and 24, and the temperature rises. When the temperatures of the supply plate 21 and the solubilization tank 2 reach a predetermined set value, the solubilization device 1 is in a standby state.

In this state, the organic waste 25 is mounted on the supply plate 21 of the organic waste supply mechanism 3 by a crane (not shown). Then, the organic waste 25 is heated by the supply plate 21. And scraper 2
2 is driven by the drive mechanism 23, and the scraper 2
The organic waste 25 is pushed forward by the forward movement of 2, and the organic waste 25 is put into the solubilization tank 2.

On the other hand, in the solid alkaline agent supply mechanism 4, the solid alkaline agent supply valve 3 is controlled by the controller 5.
3 is operated and the solid alkaline agent supply valve 33 is opened, so that the solid alkaline agent 32 stored in the solid alkaline agent storage tank 31 is charged into the solubilization tank 2.

In this state, the organic waste 12 and the solid alkaline agent 32 charged in the solubilization tank 2 are heated by the hot water jacket 11 and set to a predetermined temperature determined by the controller 5. It In this case, when performing the solubilization treatment at a temperature suitable for the medium temperature methane fermentation condition, the temperature in the solubilization tank 2 is set to an atmosphere of 35 ° C. or higher. When performing the solubilization treatment at a high temperature, the temperature inside the solubilization tank 2 is set to an atmosphere of 60 ° C. or higher.

In this state, when the ammonia component contained in the organic waste is removed, the control unit 5 causes the steam / warm water supply mechanism 7 to supply the organic waste 12 with steam / hot water 13, To heat.

Further, the organic waste 12 and the solid alkaline agent 32 put into the solubilization tank 2 are crushed and stirred by the crushing stirring mechanism 8 controlled by the controller 5.
In this case, as shown in FIG. 2, the organic waste 12 is mixed with the rotary movement 48 of the stirring screw 41 and the stirring screw 42.
It is drawn into the constant gap 47 by the rotating motion 49 of the above, and is crushed and stirred while moving in the horizontal direction 50.

In this state, as shown in FIG. 3, the solid alkali pieces 42 on the granules enter the mass 41 of the organic waste 12 and the high PH portion 43 near the solid alkali pieces 42, Polymer waste is destroyed. Further, a PH gradient 44 is formed from around the solid alkali pieces 42 in the organic waste toward the outside of the lump 41, and the organic waste is decomposed by the bacteria brought into the organic waste in the PH gradient 44. It In this way, the solid alkaline pieces 42 and the lumps 41 are
By positively utilizing the surrounding PH gradient 44, solubilization of organic waste is promoted.

Here, when the temperature in the solubilization tank 2 is set to an atmosphere of 35 ° C. or higher in order to obtain the medium temperature methane fermentation condition, the organic waste can be treated under an atmosphere suitable for the medium temperature methane fermentation. Solution is promoted. Further, when the temperature in the solubilization tank 2 is set to an atmosphere of 60 ° C. or higher in order to perform the solubilization process at a high temperature, the solubilization of the organic waste is promoted at a high temperature.

Further, in order to reduce the amount of ammonia and the like which hinders the methane fermentation efficiency of the organic waste, the steam / hot water supply mechanism 7 supplies steam / hot water 13 to the organic waste 12, whereby the organic waste When 12 is heated, the ammonia component contained in the organic waste 12 becomes the organic waste 1
2 is removed, and the amount of methane gas recovered from methane fermentation is increased.

Further, by the crushing stirring mechanism 7 shown in FIG.
The organic waste 12 and the solid alkaline agent 32 are crushed and agitated, and the destruction of the above-mentioned polymer waste and the decomposition by the bacteria are further promoted, and the solubilization of the organic waste is further promoted.

After the organic waste 12 is solubilized by the above process, the organic waste 12 passes through the organic waste discharge port 10 attached to the bottom portion 9 of the solubilization tank 2 and the organic waste 12. When the discharge valve 15 opens, the methane fermentation tank 1
Sent to 6.

As described above, in this apparatus for solubilizing organic waste, a solid alkaline agent is added to the organic waste to destroy the polymer waste and decompose it by the bacteria in the PH gradient 44. As it proceeds, the solubilization of the organic waste can be promoted.

Further, when the temperature of the organic waste 12 and the solid alkaline agent 32 charged in the solubilization tank 2 is set under the atmosphere of 35 ° C. or higher, the organic waste suitable for the medium temperature methane fermentation condition is used. The solubilization of the substance can be promoted.

Further, when the temperature of the organic waste 12 and the solid alkaline agent 32 charged in the solubilization tank 2 is set under an atmosphere of 60 ° C. or higher, the organic waste can be treated under high temperature conditions. The solubilization can be promoted.

Further, by the steam / hot water supply mechanism 7,
When the organic waste 12 and the solid alkaline agent 32 are heated to a high temperature, ammonia and the like that hinder the methane fermentation efficiency of the organic waste can be removed, and high efficiency of methane fermentation can be achieved.

Further, the crushing and stirring mechanism 8 crushes and stirs the organic waste 12 and the solid alkaline agent 32, and the destruction of the polymer waste and the decomposition by the bacterium described above are further promoted. The solubilization can be further promoted.

In the present embodiment, the domestic waste such as household waste and business waste is mainly subjected to the solubilization treatment, but it is also applicable to all the organic waste such as sewage sludge and manure. Good.

Further, in the present embodiment, the solid alkaline agent shown in FIG.
3 opened, the solid alkaline agent 32 stored in the solid alkaline agent storage tank 31 was charged into the solubilization tank 2, but the solid alkaline agent supply valve 34 was provided to The supply valve 34 may be opened and the solid alkaline agent 32 may be added to the organic waste 12.

Further, in the present embodiment, the organic waste 12 and the solid alkaline agent 32 are heated under an atmosphere of 60 ° C. or higher to inhibit the methane fermentation efficiency of the organic waste, such as ammonia. However, other components which can be removed by heating are not limited to ammonia.

[0045]

EXAMPLES Next, the present invention will be described concretely with reference to Examples and Comparative Examples. The organic waste solubilization treatment apparatus of the present invention uses organic waste as polluted water containing solid waste (solid content 5
(~ 30%) is mounted on the organic waste supply mechanism 3 and put into the solubilization tank 2. About 50 (g / kg raw garbage) of the solid alkaline agent Ca (OH) 2 stored in the solid alkaline agent supply mechanism 4 is put into the solubilization tank. When the organic waste and the solid alkaline agent are crushed and stirred by the crushing and stirring mechanism 7, the alkaline agent sunk into the organic waste in a dumpling shape. Stirring is aerobic or slightly aerobic. The solubilized organic waste is stopped at a pH of 8 or less, the temperature is 20 ° C. to 35 ° C. at room temperature, and the treatment time is 1 to 2 days. When PH is 5.5 or less, an alkaline solution is added to make it neutral.

FIG. 4 shows methane accumulation gas in methane fermentation when the organic waste was aerobically solubilized before and after PH8, when it was around PH10, and when it was untreated. It is the result of comparing the amounts. For example, the amount of accumulated gas that is solubilized by the present invention and obtained by methane fermentation from 40 g of organic waste of PH8 is 1250.
0 ml, 10500 ml for organic waste of PH10,
Untreated organic waste amounted to 3500 ml.

Table 1 compares the volume reduction rates in methane fermentation after the solubilization treatment.

[0048]

[Table 1]

The untreated solid volume reduction rate was 30.8%, while the solubilized solid volume reduction rate was 40.6%. The untreated organic matter volume reduction rate was 54.3%, while the solubilization-treated organic matter volume reduction rate was 70 to 90%.

In the present example, Ca (OH) 2 as a solid alkaline agent was added to the solubilization tank at about 50 (g / k).
However, another solid alkaline agent may be added. When NaOH is mixed, about 2 (g / kg raw garbage) can be added. Further, the solid alkaline agent may be a mixture agent in which Ca (OH) 2 is mainly used and NaOH and NaCO3 are mixed.

[0051]

As described above, according to the first aspect of the invention, the solid alkaline agent is added to the organic waste to destroy the polymer waste in the organic waste and to prevent PH.
Since the decomposition by the bacteria in the gradient proceeds, the effect of promoting the solubilization of the organic waste can be obtained.

According to the second aspect of the present invention, it is possible to obtain the effect of promoting the solubilization of the organic waste suitable for the medium temperature methane fermentation condition.

According to the invention of claim 3, it is possible to obtain the effect that the solubilization of the organic waste can be promoted under high temperature conditions.

According to the fourth aspect of the present invention, it is possible to remove the components that inhibit the methane fermentation efficiency of the organic waste, and to obtain the effect of achieving high efficiency of methane fermentation.

According to the invention of claim 5, the solid alkaline agent is added to the organic waste, the destruction of the polymer waste in the organic waste and the decomposition by the bacteria in the PH gradient proceed, The effect of promoting the solubilization of organic waste is obtained.

According to the invention of claim 6, it is possible to remove a component which inhibits the methane fermentation efficiency of the organic waste, and
The effect of promoting the solubilization of organic waste is obtained.

According to the invention of claim 7, the organic waste to which the solid alkaline agent is supplied is continuously crushed and stirred by the crushing stirring mechanism. As a result, the effect of further promoting the solubilization of the organic waste can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of an organic waste solubilization treatment device of the present invention.

FIG. 2 is a plan view of essential parts showing an embodiment of a stirring blade of a crushing stirring mechanism included in the organic waste solubilization treatment device of the present invention.

[Fig. 3] Fig. 3 is a schematic diagram showing a PH distribution in a mass of the organic waste during the solubilization treatment in the embodiment of the organic waste solubilization treatment apparatus of the present invention.

FIG. 4 is a graph showing the results of comparing the amount of accumulated methane gas in methane fermentation after the solubilization treatment, which shows the embodiment of the solubilization treatment apparatus for organic waste of the present invention.

[Explanation of symbols]

1 Organic waste solubilization treatment equipment 2 Solubilization tank 3 Organic waste supply mechanism 4 Solid alkaline agent supply mechanism 7 Steam / hot water supply mechanism 8 Crushing stirring mechanism 45,46 Stirring blade 32 Solid alkaline agent 12,25 Organic waste 13 Steam or hot water

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI theme code (reference) B09B 3/00 D 304H 304Z (72) Inventor Shigeru Uchiyama 1 Shin-Nakahara-cho, Isogo-ku, Yokohama, Kanagawa Ishi Kawashima Harima Heavy Industries Co., Ltd. Machinery & Plant Development Center (72) Inventor Mamoru Nakayama 1 Shinshinarahara-cho, Isogo-ku, Yokohama, Kanagawa Ishi Kawashima Harima Heavy Industries Co., Ltd. Machinery & Plant Development Center (72) Inventor Yutaka Kuriyama Tokyo 3-2-16 Toyosu Toyosu, Koto-ku, Ishikawajima Harima Heavy Industries, Ltd. Tokyo Engineering Center (72) Inventor Makoto Kitano 3-2-16, Toyosu, Ishikawajima, Koto-ku, Tokyo F-term inside Tokyo Engineering Center, Harima Heavy Industries (Reference) ) 4D004 AA02 AA03 CA04 CA15 CA18 CA19 CA22 CA34 CB28 CB 31 CB42 CC12 DA06 DA08 4D059 AA01 AA03 AA07 BA01 BA12 BA21 BA31 BA56 BJ02 BJ07 BK11 BK12 BK15 DA05 EB06 4G078 AA06 AB20 BA01 BA07 DA09

Claims (7)

[Claims] 1. A method for solubilizing an organic waste, which is performed as a preceding step of methane fermentation of the organic waste, wherein a solid alkaline agent is added to the organic mechanical waste to solubilize the organic waste. A method for solubilizing an organic waste, which is characterized in that 2. The method for solubilizing an organic waste according to claim 1, wherein the organic waste is solubilized in an atmosphere at a temperature of 35 ° C. or higher. Law. 3. The method for solubilizing an organic waste according to claim 1 or 2, wherein the organic waste is solubilized in an atmosphere having a temperature of 60 ° C. or higher. Solubilization treatment method. 4. The method for solubilizing an organic waste according to any one of claims 1 to 3, wherein the object to be treated is heated with steam or warm water. Solution treatment method. 5. A solubilization tank, an organic waste supply mechanism for supplying organic waste to the solubilization tank, an organic waste on the organic waste supply mechanism, or an organic waste in the solubilization tank. An apparatus for solubilizing an organic waste, comprising a solid alkaline agent supply mechanism for supplying a solid alkaline agent to waste. 6. The organic waste solubilization treatment apparatus according to claim 5, further comprising a steam / hot water supply mechanism for supplying steam or hot water to the waste in the solubilization tank. Solubilization equipment for organic waste. 7. The apparatus for solubilizing an organic waste according to claim 5 or 6, wherein a crushing stirring mechanism for crushing and stirring the waste is provided in the treatment tank, and the crushing stirring mechanisms are mutually axial lines. 2. A device for solubilizing organic waste, comprising: rotating shafts arranged in parallel with each other; and stirring blades spirally provided on these rotating shafts.