Container disposal method

Abstract

To provide a method capable of safely and simply disposing of a container that has stored water-prohibitive or spontaneously combustible substances.SOLUTION: A container disposal method that has stored water-prohibitive or spontaneously combustible substances, comprises the steps of: attaching a plug to a valve opening of a container, which opens when a certain temperature or pressure is reached; opening the valve opening with the plug attached; and inputting the container into a heating furnace with the plug attached and the valve opening open to heat it.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for disposing of containers. [Background technology]

[0002] In a container that contains a water-resistant or pyrophoric substance that ignites and poses the risk of explosion when it comes into contact with air or water, even a small amount of air or water cannot be allowed to get mixed in. For example, Patent Document 1 discloses a method for handling pyrophoric substances that can safely handle pyrophoric substances by preventing air from leaking into piping from a valve, and a valve device used therefor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-232291 A Summary of the Invention [Problem to be solved by the invention]

[0004] When disposing of containers (such as used gas cylinders) that have contained water-inhibiting or spontaneously combustible substances as described above by incineration, it is necessary to open the container before placing it in the incinerator in order to prevent explosion. However, opening the container entails the risk of fire or the release of toxic gases, making it an extremely difficult task.

[0005] On the other hand, there is an increasing need for the disposal of containers that contain water-insensitive or pyrophoric substances, making it difficult for users to secure disposal sites. This has led to concerns that the containers may corrode due to long-term storage.

[0006] An object of one embodiment of the present invention is to provide a method for safely and easily disposing of a container that has contained a water-insensitive or pyrophoric substance. [Means for solving the problem]

[0007] The first aspect of the present invention is A method for disposing of a container that has contained a water-insensitive or pyrophoric substance, comprising the steps of: A step of attaching a plug to a valve opening of the container, the plug being opened when a certain temperature or pressure is reached; opening the valve port while the plug is attached and the valve port is open; and placing the container with the stopper attached in a heating furnace and heating the container.

[0008] A second aspect of the present invention is In the method for waste disposal of a container according to the first aspect, the plug is a soluble plug that opens when a low-melting point metal filled inside melts.

[0009] A third aspect of the present invention is The heating step includes: a first heating step of heating the low-melting point metal to a temperature at which the low-melting point metal melts and opening the melt plug; and a second heating step of heating the container to a temperature higher than that of the first heating step to remove the substance remaining in the container.

[0010] A fourth aspect of the present invention is In the container waste disposal method according to the second aspect, the melting point of the low-melting point metal is 60°C or higher and 110°C or lower.

[0011] A fifth aspect of the present invention is In the method for disposing of a container according to the second aspect, the maximum operating pressure of the soluble plug is lower than a pressure test pressure of the container.

[0012] A sixth aspect of the present invention is a method for producing a composition comprising the steps of: In the container disposal method according to the third aspect, in the first heating step, a temperature rise rate is set slower than that in the second heating step.

[0013] A seventh aspect of the present invention is a method for producing a composition comprising the steps of: This is a method for disposing of a container according to any one of the first to sixth aspects, wherein the substance is a Class 3 hazardous material. Effect of the Invention

[0014] According to one embodiment of the present invention, a container that has contained a water-inhibiting or pyrophoric substance can be disposed of safely and easily. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a flow chart showing an example of a container waste treatment method according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing a state in which a dissolving plug is attached to a valve opening of a container according to the first embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] [Details of the embodiment of the present invention] An embodiment of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0017] First embodiment of the present invention (1) Container disposal method First, the container disposal method of this embodiment will be described. FIG. 1 is a flow chart showing an example of the container disposal method of this embodiment. As shown in FIG. 1, the container disposal method of this embodiment has, for example, a residual substance confirmation step S100, a dissolving plug attachment step S110, a valve opening step S120, and a heating step S130. The heating step S130 has, for example, a first heating step S131 and a second heating step S132. After the heating step S130, an exhaust gas treatment step 10 may be performed as necessary.

[0018] The container to be disposed of in this embodiment is a container such as a waste cylinder that contains a water-phobic or pyrophoric substance (hereinafter, simply referred to as a substance). Examples of the water-phobic or pyrophoric substance include t-butylphosphine, diisobutylaluminum chloride, dimethylaluminum chloride, diethylzinc, triethylborane, tributylborane, potassium, sodium, alkylaluminum (trimethylaluminum, triethylaluminum, triisobutylaluminum, etc.), alkyllithium, tertiarybutylarsine (TBAs), tertiarybutylphosphine (TBP), 1.1-dimethylhydrazine (UDMHy), and ditertiarybutylsilane (DTBSi). In this embodiment, a case will be described in which a container that contains dimethylsulfide borane, which is a Class 3 hazardous material, is disposed of.

[0019] (Residual substance confirmation process S100) The residual substance confirmation step S100 is, for example, a step of confirming the presence or absence of a substance in a container and the amount of the remaining substance. There is a high possibility that a small amount of substance remains in a used container, and if the sealed state is opened, there is a risk of fire, etc. Therefore, in the residual substance confirmation step S100, the residual substance is confirmed without opening the valve opening of the container. Specifically, for example, the mass of the container may be measured to confirm the amount of the remaining substance.

[0020] In the residual substance confirmation step S100, if the amount of substance remaining in the container is large (for example, 5% or more of the initial filling amount), the remaining substance may be removed. The remaining substance can be removed by a known method, for example, by sealing an inert gas in the container. Even if the remaining substance is removed in this step, it is highly likely that a small amount of substance still remains in the container, so it is necessary to safely process it using the steps described below.

[0021] (Dissolving plug installation process S110) FIG. 2 is a schematic diagram showing a state where a dissolving plug is attached to a valve port of a container. A valve 21 is installed in a container 20 in which a water-resistant or spontaneously combustible substance is contained. The dissolving plug attachment step S110 is, for example, a step of attaching a dissolving plug 23 to a valve port 22 formed at the tip of the valve 21 of the container 20, which opens when a temperature reaches a certain level or higher by melting a low-melting point metal filled inside. When the container 20 has two or more valve ports 22, it is sufficient to attach a dissolving plug 23 to at least one of the valve ports 22. From the viewpoint of ensuring greater safety, it is preferable to attach a dissolving plug 23 to each of the valve ports 22. When the diameters of the valve port 22 and the dissolving plug 23 do not match, the dissolving plug 23 may be attached to the valve port 22 via a joint 24 as shown in FIG. 2.

[0022] Here, a typical high-pressure gas cylinder may be equipped with a dissolving plug as a safety device that prevents the cylinder from bursting by releasing the high-pressure gas when an abnormal temperature rise occurs. However, the containers to be disposed of in this embodiment are containers that contain water-resistant or pyrophoric substances, and for safety reasons, they rarely come equipped with a dissolving plug. In this embodiment, the dissolving plug is used not as a safety device that prevents the container from bursting when an abnormal temperature rise occurs, but as a plug for safely and easily opening the inside of the container in a heating furnace.

[0023] The soluble plug used can be a commercially available one. The melting point of the low melting point metal filled inside the soluble plug is preferably, for example, 60°C or higher and 110°C or lower. This makes it possible to prevent the soluble plug from being in an open state before the heating step S130, while allowing the soluble plug to be in an open state safely and easily in the heating step S130.

[0024] The maximum operating pressure of the fusible plug is, for example, preferably lower than the pressure test pressure of the container, and more preferably 2 / 3 or less of the pressure test pressure of the container, which makes it possible to prevent the pressure inside the container from exceeding the pressure test pressure in the heating step S130.

[0025] (Valve opening process S120) The valve opening step S120 is, for example, a step of opening the valve opening of the container with a dissolving plug attached to the container. Even if the valve opening is opened, the inside of the container is kept sealed by the dissolving plug, so the substance inside the container does not come into contact with air or water. If the container has two or more valve openings, it is sufficient to open only the valve opening to which the dissolving plug is attached in the dissolving plug attachment step S110.

[0026] (Heating process S130) The heating step S130 is, for example, a step of attaching a dissolving plug to a container, placing the container in a heating furnace with the valve opening open, and heating the container. The type of heating furnace used in the heating step S130 is not particularly limited, but it is preferable to use a batch-type heating furnace in which the heating temperature and the heating rate can be easily controlled.

[0027] Of the heating steps S130, the first heating step S131 is a step of heating the soluble plug to a temperature at which the low melting point metal melts (preferably within a temperature range of the melting point of the low melting point metal +5°C to +30°C) to leave the soluble plug in an open state. This allows the container to be opened safely in the heating furnace. Note that in the first heating step S131, from the viewpoint of ensuring that the soluble plug is in an open state, it is preferable to maintain the temperature at which the low melting point metal melts for a predetermined period of time (e.g., about 5 to 30 minutes).

[0028] In the first heating step S131, for example, it is preferable to set the temperature increase rate slower than in the second heating step S132 described below. This allows the dissolving plug to be opened safely and reliably. Specifically, for example, it is preferable to set the temperature increase rate to 1° C. / min or more and 20° C. / min.

[0029] Of the heating step S130, the second heating step S132 is a step of, for example, heating the container to a temperature (e.g., about 400°C to 800°C) higher than that of the first heating step S131 to remove any substances remaining in the container. This makes it possible to safely and easily remove any substances remaining in the container and dispose of the container. Note that, in the second heating step S132, from the viewpoint of completely removing any substances remaining in the container, it is preferable to maintain the container at a temperature higher than that of the first heating step S131 for a predetermined time (e.g., 30 minutes or more and 120 minutes or less).

[0030] (Exhaust gas treatment process 10) In addition, if the substances remaining in the container are completely decomposed and rendered harmless in the heating step S130, this is not necessary, but if exhaust gas that requires treatment is generated, it is desirable to further perform the exhaust gas treatment step 10 to treat the exhaust gas. Typically, for example, a secondary combustion step 10a is provided, and if necessary, a quenching step 10b, a dust removal / desalting step 10c, and a soot dust treatment step 10d can be provided. Exhaust gas is discharged from the heating furnace during heating in the heating step S130. This exhaust gas is first introduced into a secondary combustion furnace, where it is combusted at a high temperature of 850°C or higher to combust and render harmless the exhaust gas discharged from the container. If there is any cinder discharged during secondary combustion, it is treated separately. The exhaust gas after the secondary combustion is introduced into a heat exchanger, where heat is exchanged with the supply air by a blower provided in association with the heat exchanger, and the exhaust gas is sent to a downstream quenching tower. Here, the supply air used for the heat exchange may be introduced into a heating furnace as combustion air after the heat exchange. In the quenching tower, the exhaust gas is rapidly cooled, for example, by heat exchange with cooling water, and the cooled exhaust gas is sent to a dust collector at the downstream stage. By rapidly cooling the exhaust gas, the dust collector and exhaust fan located at the downstream stage of the quenching tower are protected from heat damage, and the life of the equipment is improved. Here, when the exhaust gas is introduced from the quenching tower to the dust collector, chemicals such as hydrated lime and activated carbon may be added from a supply unit as necessary.

[0031] <Other embodiments of the present invention> Although the embodiment of the present invention has been specifically described above, the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the gist of the present invention. For example, in the above embodiment, a dissolving plug is attached to the valve opening of a container, but the plug attached to the valve opening is not limited to a dissolving plug and may be any plug that opens when the temperature or pressure exceeds a certain level. [Explanation of symbols]

[0032] S100 Residual substance confirmation process S110 Dissolving plug installation process S120 Valve opening process S130 Heating process S131 1st heating process S132 2nd heating process 10 Exhaust gas treatment process 10a Secondary combustion process 10b Rapid cooling process 10c Dust removal / desalination process 10d Soot and dust treatment process 20 containers 21 Valve 22 Valve mouth 23 Melting plug 24 Joints

Claims

1. A method for disposing of a container that has contained a water-insensitive or pyrophoric substance, comprising the steps of: A step of attaching a plug to a valve opening of the container, the plug being opened when a certain temperature or pressure is reached; opening the valve port with the plug attached; and placing the container in a heating furnace with the stopper attached and the valve opening open to heat the container.

2. 2. The method for disposing of a container according to claim 1, wherein the plug is a soluble plug that opens when a low-melting point metal filled inside melts.

3. The heating step includes: a first heating step of heating the low-melting point metal to a temperature at which the low-melting point metal melts and opening the melt plug; 3. The method for waste disposal of containers according to claim 2, further comprising a second heating step of heating the container to a temperature higher than that of the first heating step to remove the substance remaining in the container.

4. 3. The method for waste disposal of containers according to claim 2, wherein the melting point of the low-melting point metal is 60°C or higher and 110°C or lower.

5. 3. The method for disposing of a container according to claim 2, wherein the maximum operating pressure of the fusible plug is lower than a pressure test pressure of the container.

6. 4. The method for waste disposal of a container according to claim 3, wherein the temperature rise rate in the first heating step is slower than that in the second heating step.

7. The method for disposing of a container according to any one of claims 1 to 6, wherein the substance is a Class 3 hazardous material.

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