Methods for rendering spontaneously combustible or water-repellent substances harmless

Abstract

To provide a method for rendering pyrophoric or water-reactive substance harmless, and a system for use in the method.SOLUTION: The present invention provides a method for rendering an organic metal compound and / or a metal compound harmless, the method including the steps of: (1) bringing an organic metal compound and / or a metal compound including an organic solvent into contact with an acid aqueous solution; and (2) separating the process liquid obtained in (1) into an organic layer and an aqueous layer, to recover the organic layer to be recycled to the step (1), and to optionally neutralize the aqueous layer with an alkali aqueous solution.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention provides a method for rendering pyrophoric or water-prone substances harmless, and a system for use in the method. [Background technology]

[0002] Pyrophoric or water-repellent substances, such as organometallic compounds like alkylaluminum and metallic zinc compounds, are essential in chemical and semiconductor factories as polymerization promoters for plastics and synthetic rubber, polymerization catalysts for resins like polyethylene and polypropylene, and for the production of insulating films for solar cells and organic semiconductors. The problem with these organometallic and metallic compounds is that they are extremely dangerous to handle. For example, alkylaluminum spontaneously ignites when exposed to air, reacts explosively and generates heat when exposed to water, and can thermally decompose at temperatures as high as 200°C, causing chain explosions, potentially leading to serious accidents and disasters.

[0003] Alkyl foams and the like are used to extinguish fires caused by alkyl aluminum (Non-Patent Document 1). It is also known that the explosiveness of alkyl aluminum can be reduced by diluting it with an organic solvent such as a hydrocarbon (Non-Patent Document 2). However, in the latter case, large amounts of organic solvents are required in facilities that handle large amounts of such hazardous materials, such as factories, and the waste liquid of used organic solvents can lead to environmental problems.

[0004] Against this background, a method of treating alkylaluminum with a solid base has been proposed (Patent Document 1). However, when metallic aluminum is included, the treatment speed is slow and takes a long time. Furthermore, it is necessary to remove the aluminum-derived solids in the reaction product, and the filterability for removing the solids is poor. Therefore, there is a strong demand for a method for safely and efficiently treating and rendering harmless such pyrophoric or water-repellent substances. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 4,018,867 [Non-patent literature]

[0006] [Non-Patent Document 1] Safety & Tomorrow No.166 (2016.3), pp.49-57 [Non-patent document 2] Safety Engineering, vol.6, No.2(1967). pp.155-159 Summary of the Invention [Problem to be solved by the invention]

[0007] The present inventors have discovered a method for safely and efficiently treating and rendering non-toxic pyrophoric or water-phobic substances harmless, and therefore the present invention provides such a method and a system for use therein. [Means for solving the problem]

[0008] The present invention includes the following inventions. 1. A method for detoxifying organometallic compounds and / or metallic compounds, comprising: (1) contacting an organometallic compound and / or a metal compound containing an organic solvent with an aqueous acid; and (2) separating the process solution obtained in (1) into an organic layer and an aqueous layer, recovering the organic layer and recycling it to step (1), and optionally neutralizing the aqueous layer with an alkaline aqueous solution; A method comprising: 2. The method of claim 1, wherein the organometallic compound is selected from the group consisting of aluminum alkyls, zinc alkyls, and magnesium alkyls. 3. The method of claim 1, wherein the metal alloy is selected from the group consisting of metallic aluminum, metallic zinc, and aluminum-magnesium alloy. 4. The method according to any one of 1 to 3, wherein the alkyl aluminum is selected from the group consisting of triethyl aluminum and triisobutyl aluminum. 5. The method according to 1 or 2, wherein the organic solvent is a petroleum hydrocarbon, an aliphatic hydrocarbon, or an alicyclic hydrocarbon solvent. 6. The method according to 1 or 2, wherein the organic solvent is kerosene. 7. The method according to any one of 1 to 6, wherein the organometallic compound and / or metal compound containing the organic solvent is diluted in the organic solvent so that the organometallic compound and / or metal compound has a concentration of 0.1 to 5 wt %. 8. The method according to any one of 1 to 7, wherein the aqueous acid solution is an aqueous hydrochloric acid solution. 9. The method according to 8, wherein the hydrochloric acid concentration of the aqueous hydrochloric acid solution is 15 to 25% by weight. 10. The method according to any one of 1 to 9, wherein in step (1), the organometallic compound and / or metal compound containing an organic solvent is contacted with the aqueous acid solution in a volume ratio of 10:1 to 1:1. 11. The method according to 10, wherein the organometallic compound and / or metal compound containing an organic solvent is contacted with the aqueous acid solution in a volume ratio of 5:1 to 2:1. 12. The method according to any one of 1 to 11, wherein in step (1), the organometallic compound and / or metal compound containing an organic solvent is contacted with the aqueous acid solution at a temperature of 40 to 60°C. 13. The method according to any one of claims 1 to 12, wherein step (2) further comprises a step of neutralizing the aqueous layer with an alkaline aqueous solution. 14. The method of claim 13, wherein the alkaline aqueous solution is calcium hydroxide. [Effects of the Invention]

[0009] The present invention makes it possible to safely and efficiently detoxify pyrophoric and water-prohibitive substances. The organic solvents generated during the detoxification process can be recovered and reused for further detoxification processes. [Brief explanation of the drawings]

[0010] [Figure 1] A system for use in the detoxification method of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention provides a method for detoxifying organometallic compounds and / or metallic compounds, the method comprising the steps of: (1) contacting an organometallic compound and / or a metal compound containing an organic solvent with an aqueous acid; and (2) separating the process solution obtained in (1) into an organic layer and an aqueous layer, recovering the organic layer and recycling it to step (1), and optionally neutralizing the aqueous layer with an alkaline aqueous solution; Includes.

[0012] The organometallic compounds and metal compounds rendered harmless in the present invention refer to pyrophoric or water-repellent substances. Pyrophoric substances include solid or liquid substances that are prone to spontaneous combustion in air. Furthermore, "water-repellent substances" include solid or liquid substances that ignite or generate flammable gases when exposed to water. In this application, "detoxification" refers to a case in which the resulting organic layer is colorless and transparent or nearly colorless and transparent, and its moisture content is below a predetermined value, for example, 100 ppm or less.

[0013] Examples of pyrophoric or water-repellent organometallic compounds include, but are not limited to, alkylaluminum compounds, alkyllithium compounds, diethylzinc, etc. Examples of alkylaluminum compounds include trialkylaluminums such as trimethylaluminum, triethylaluminum, dimethylaluminum, diethylaluminum, and triisobutylaluminum, and alkylaluminum chlorides such as ethylaluminum sesquichloride, methylaluminum sesquichloride, diethylaluminum chloride, dimethylaluminum chloride, ethylaluminum dichloride, and methlaluminum dichloride. Examples of alkyllithium compounds include methyllithium, n-butyllithium, sec-butyllithium, and tert-butyllithium.

[0014] Examples of pyrophoric or water-repellent metal compounds include metallic aluminum, metallic zinc, metallic potassium, metallic sodium, metallic lithium, metallic calcium, metallic barium, sodium hydride, lithium hydride, calcium hydride, aluminum carbide, and calcium carbide.

[0015] The organic solvent used in the above step (1) is selected from solvents that do not substantially react with the organometallic compound or metal compound to be detoxified. For example, when the organometallic compound is an alkylaluminum, petroleum hydrocarbons such as, but not limited to, crude oil, kerosene, naphtha, butane, and the like are used. In addition, the substances to be detoxified, provided that they do not substantially react with organometallic compounds and / or metal compounds, include aliphatic hydrocarbons, such as normal pentane, normal hexane, normal heptane, normal octane, normal nonane, normal decane, normal undecane, normal dodecane, normal tridecane, normal tetradecane, and other straight-chain saturated aliphatic hydrocarbons; branched-chain saturated aliphatic hydrocarbons such as 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, and 2,2,4-trimethylpentane; cyclopentane, methylcyclopentane, ethylcyclopentane, isopropylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, decahydronaphthalene, dicyclohexane, and the like. Examples of such hydrocarbons include cyclic saturated aliphatic hydrocarbons such as hexyl and 1,3,5,7-cyclooctatetraene, linear unsaturated aliphatic hydrocarbons such as 1,3-pentadiene and 2,4-hexadiene, branched unsaturated aliphatic hydrocarbons such as 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene and 2,5-dimethyl-2,4-hexadiene, cyclic unsaturated aliphatic hydrocarbons such as cyclopentene, methylcyclopentene, ethylcyclopentene, isopropylcyclopentene, dimethylcyclopentene, cyclohexene, methylcyclohexene, ethylcyclohexene and dimethylcyclohexene, and aromatic hydrocarbons such as benzene, toluene, dimethylbenzene, trimethylbenzene, ethylbenzene, tert-butylmethylbenzene, naphthalene, biphenyl and phenylcyclohexane. These may be used alone or in combination of two or more.

[0016] The concentration of the organic solvent contained in the organometallic compound and / or metal compound is not particularly limited, but the organic solvent is used so that the concentration of the organometallic compound and / or metal compound relative to the organic solvent is 0.1 to 5 wt %, preferably 0.1 to 2 wt %.

[0017] The aqueous acid solution used in step (1) is selected from those that maintain the prepared solution, which is in a solution or suspension state and contains the organometallic compound and / or metal compound to be detoxified, in a solution state or convert it from a suspension state to a solution state. For example, low-molecular-weight alkyl aluminum is a colorless, transparent liquid at room temperature and pressure, and an acid working solution that remains colorless and transparent even when diluted is selected. Examples of acids that can be selected include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, and organic acids such as citric acid, oxalic acid, acetic acid, and paratoluenesulfonic acid. Aqueous hydrochloric acid is particularly preferred in relation to alkyl aluminum, and a concentration of 5 to 40 wt %, particularly preferably 10 to 30 wt %, and most preferably 20 wt % is used.

[0018] The mixing of the organic solvent-containing organometallic compound and / or metal compound with the aqueous acid solution is not particularly limited, and ideally an excess amount of the aqueous acid solution is used, but in consideration of the subsequent treatment steps, it is preferable to set an upper limit on the amount of the aqueous acid solution used. Although not particularly limited, the organic solvent-containing organometallic compound and / or metal compound with the aqueous acid solution are mixed and contacted at a volume ratio of 10:1 to 1:1, preferably 5:1 to 2:1.

[0019] The process solution obtained in step (1) is allowed to settle over several hours, for example, 0.5 to 10 hours, preferably 1 to 5 hours, depending on the volume. "Steady state" here refers to a state in which the component composition in the reactor is constant, for example, in the case of a continuous tank reactor. The stabilized process solution is then sent to a separator and partitioned into an organic layer and an aqueous layer. A settler or the like is used as the separator. The organic layer is recovered and reused. If necessary, the aqueous layer is neutralized with an aqueous alkali solution or the like before being discarded. Examples of the aqueous alkali solution include sodium hydroxide, potassium hydroxide, and calcium hydroxide.

[0020] The method of the present invention is carried out so that the solution in each step is kept at a high temperature, preferably 20 to 80° C., more preferably 30 to 70° C., and even more preferably 40 to 60° C. For this reason, the method of the present invention is preferably carried out in equipment such as a reaction vessel equipped with a cooling means.

[0021] The present invention further provides a system for carrying out the above-mentioned detoxification treatment process, a schematic diagram of which is shown in Figure 1. The organic solvent containing the organometallic compound and / or metal compound can also be adjusted in an adjustment tank 1. The adjusted solution is fed via feed pump 8, and the aqueous acid solution via feed pump 9, to the first reactor 3, where they are mixed. In the system shown in the figure, the mixture is mixed in the first reactor 3, and once it has reached a certain level of stability, it is further fed to the second reactor 4 to ensure stability. If necessary, further reactors for stabilization, such as a third, fourth, etc., may follow. The volumes of the first and second reactors may be the same or different. For example, the volume of the second reactor may be half that of the first reactor. The stabilized reaction solution is fed to a settler 5, where it is partitioned into an organic layer 6 and an aqueous layer 7. Although not shown, the organic layer 6 is recovered and reused. The organic layer 6 may be further treated with a base or activated carbon to improve its purity. The aqueous layer 7 may be treated with an alkaline working solution or the like and then discarded.

[0022] According to the present invention, the organic solvent generated in the detoxification treatment can be recovered and reused. The method of the present invention can be used in both a continuous system and a batch system.

[0023] All documents mentioned herein are incorporated by reference in their entirety.

[0024] The following examples of the present invention are for illustrative purposes only and do not limit the technical scope of the present invention. The technical scope of the present invention is limited only by the claims. The present invention may be modified, for example, by adding, deleting, or substituting components of the present invention, provided that the modifications do not depart from the spirit of the present invention. [Example]

[0025] The present invention will be described in more detail below with reference to examples, but these examples are not intended to limit the present invention in any way.

[0026] Example 1 A 20 wt% hydrochloric acid solution (61.0 g, 0.33 mol) and kerosene (150 g) were placed in a 1-L separable flask (first reactor). Next, triethylaluminum (87.7 g, 0.77 mol) and metallic aluminum (20.6 g, 0.76 mol) were diluted with kerosene (4893 g) to prepare a solution with an Al concentration of 1.0 wt%. This solution was continuously fed into the first reactor under vigorously stirring conditions using a feed pump at approximately 800 mL / hr to maintain the internal temperature at 50°C. Similarly, a 20 wt% hydrochloric acid solution (1542 g, 8.45 mol as HCl) was fed at approximately 200 mL / hr. The HCl / Al molar ratio was adjusted to 6. The transfer from the 1 L separable flask (first reactor) to the 0.5 L separable flask (second reactor) and from the 0.5 L separable flask (second reactor) to the 1 L settler was also carried out at a rate of approximately 1 L / hr using a feed pump, and the mixture was allowed to settle over 3 hours. After that, the adjusted solution was treated under the same conditions as for the stabilization, while the organic layer and aqueous layer were continuously recovered from the settler, and 2274 g of the organic layer and 1021 g of the aqueous layer were obtained as the distillate after the stabilization.

[0027] The recovered solution on the organic layer side was a colorless clear liquid with a water content of 87.2 ppm. 10 g of the distillate from the aqueous layer was collected and diluted with 20 g of pure water. This diluted solution was neutralized with a 30 wt% aqueous calcium hydroxide solution (5.9 g, 24.0 mmol as Ca(OH)2) to obtain a treated solution with a pH of 4.2. The viscosity of this treated solution was measured and found to be 3.4 cP, which indicated no problems with transportability using a feed pump.

[0028] <Example 2> The process of Example 1 was repeated except that only triethylaluminum was used as the detoxifying substance. The recovered organic layer was a clear, colorless liquid with a water content of 85.5 ppm.

[0029] Example 3 The process of Example 1 was repeated except that only triisobutylaluminum was used as the detoxifying substance. The recovered organic layer was a clear, colorless liquid with a water content of 88.6 ppm.

[0030] Example 4 The process of Example 1 was repeated except that only diethylzinc was used as the detoxifying substance. The recovered organic layer was a clear, colorless liquid with a water content of 75.7 ppm.

[0031] <Example 5> The same process as in Example 1 was carried out using metallic aluminum as the detoxifying substance. The recovered solution on the organic layer side was a colorless clear liquid with a water content of 68.2 ppm.

[0032] Example 6 The same steps as in Example 1 were carried out so as to prepare a liquid having an Al concentration of 2.0 wt %. The recovered solution on the organic layer side was a colorless clear liquid with a water content of 46.8 ppm.

[0033] Example 7 The same steps as in Example 1 were carried out so as to prepare a liquid having an Al concentration of 3.0 wt %. The recovered solution on the organic layer side was a colorless clear liquid with a water content of 33.2 ppm.

[0034] Example 8 The same steps as in Example 1 were carried out using a 15 wt % aqueous hydrochloric acid solution. The recovered solution on the organic layer side was a colorless clear liquid with a water content of 75.4 ppm.

[0035] Example 9 The same steps as in Example 1 were carried out using a 25 wt % aqueous hydrochloric acid solution. The recovered solution on the organic layer side was a colorless clear liquid with a water content of 60.7 ppm.

[0036] Example 10 The same steps as in Example 1 were carried out, except that the HCl / Al molar ratio was 4. The recovered solution on the organic layer side was a colorless clear liquid with a water content of 89.2 ppm.

[0037] Example 11 The same steps as in Example 1 were carried out, except that the HCl / Al molar ratio was 9. The recovered solution on the organic layer side was a colorless clear liquid with a water content of 88.4 ppm.

[0038] Example 12 The same steps as in Example 1 were carried out, with the internal temperature of the reaction vessel being maintained at 40° C. The recovered solution on the organic layer side was a colorless clear liquid with a water content of 63.6 ppm.

[0039] Example 13 The same steps as in Example 1 were carried out, with the internal temperature of the reaction vessel maintained at 60° C. The recovered solution on the organic layer side was a colorless clear liquid with a water content of 68.1 ppm.

[0040] Example 14 The same process as in Example 1 was carried out, except that the kerosene used was the same as that in Example 2, which was repeated five times. The recovered solution in the organic layer was a clear, colorless liquid with a water content of 57.9 ppm.

[0041] Example 15 The process of Example 1 was repeated except that a mixture of triethylaluminum, metallic aluminum, diethylzinc, and metallic zinc was used as the detoxifying substance. The recovered solution on the organic layer side was a clear, colorless liquid with a water content of 89.2 ppm.

[0042] Example 16 A 0.5 L separable flask (first reactor) was charged with 3.6 wt% hydrochloric acid (61.0 g, 0.060 mol). Next, a dodecane (13.2 g, 0.077 mol) slurry containing aluminum-magnesium alloy (3.16 g, 0.025 mol) as a detoxifying substance, an alkyl aluminum (1.17 g, 0.044 mol in terms of aluminum), and magnesium chloride (19.3 g, 0.20 mol) was continuously fed via a screw feeder at a rate of approximately 37 g / hr to maintain the internal temperature at 50 °C. Similarly, a 3.6 wt% hydrochloric acid (437 g, 0.43 mol as HCl) solution was fed at a rate of approximately 437 g / hr. The HCl / Al molar ratio was adjusted to 9.1. The transfer from the 0.5 L separable flask (first reactor) to the 0.3 L separable flask (second reactor) and from the 0.3 L separable flask (second reactor) to the 0.5 L settler was also carried out using a feed pump at a rate of approximately 0.5 L / hr, and the mixture was allowed to settle over 3 hours. After that, the adjusted solution was treated under the same conditions as for the stabilization, while the organic layer and aqueous layer were continuously recovered from the settler, and 29.4 g of the organic layer and 1374 g of the aqueous layer were obtained as the distillate after the stabilization.

[0043] The recovered organic layer was a clear, colorless liquid with a water content of 60.5 ppm. 10 g of the distillate from the aqueous layer was collected and neutralized with 30 wt % calcium hydroxide aqueous solution (2.2 g, 20.1 mmol as Ca(OH)2) to obtain a treated solution with a pH of 4.0. The viscosity of this treated solution was measured and found to be 2.0 cP, which indicated no problems with transportability using a feed pump.

[0044] The steps and results of Examples 1 to 16 are summarized in the table below. [Table 1]

[0045] Although the embodiments of the present invention have been described above, the present invention is not limited to these, and the materials used, various conditions, etc. can be changed as appropriate within the scope of the invention. [Explanation of symbols]

[0046] 1 Preparation tank 2 Acid aqueous solution tank 3. First reactor 4. Second reactor 5 Settler 6 Organic layer 7 Aqueous layer 8 Feed Pump 9 Feed pump 10 Feed pump 11 Feed pump

Claims

1. A method for detoxifying organometallic compounds and / or metal compounds, comprising: (1) contacting an organometallic compound and / or a metal compound containing an organic solvent with an aqueous acid; and (2) separating the process solution obtained in (1) into an organic layer and an aqueous layer, recovering the organic layer and recycling it to the step (1), and optionally neutralizing the aqueous layer with an alkaline aqueous solution; A method comprising:

2. 2. The method of claim 1, wherein the organometallic compound is selected from the group consisting of aluminum alkyls, zinc alkyls, and magnesium alkyls.

3. 2. The method of claim 1, wherein the metal compound is selected from the group consisting of metallic aluminum, metallic zinc, and aluminum magnesium alloy.

4. 3. The method of claim 2, wherein said alkyl aluminum is selected from the group consisting of triethyl aluminum and triisobutyl aluminum.

5. 3. The method according to claim 1, wherein the organic solvent is a petroleum hydrocarbon, an aliphatic hydrocarbon, or an alicyclic hydrocarbon solvent.

6. 3. The method of claim 1 or 2, wherein the organic solvent is kerosene.

7. The method according to any one of claims 1 to 6, wherein the organometallic compound and / or metal compound containing the organic solvent is diluted in the organic solvent so that the organometallic compound and / or metal compound has a concentration of 0.1 to 5 wt%.

8. The method according to any one of claims 1 to 7, wherein the aqueous acid solution is an aqueous hydrochloric acid solution.

9. 9. The method according to claim 8, wherein the hydrochloric acid concentration of the aqueous hydrochloric acid solution is 15 to 25% by weight.

10. 10. The method according to claim 1, wherein in the step (1), the organometallic compound and / or metal compound containing an organic solvent is contacted with the aqueous acid solution in a volume ratio of 10:1 to 1:

1.

11. 11. The method of claim 10, wherein the organometallic compound and / or metal compound containing an organic solvent is contacted with the aqueous acid solution in a volume ratio of 5:1 to 2:

1.

12. The method according to any one of claims 1 to 11, wherein in the step (1), the organometallic compound and / or metal compound containing an organic solvent is contacted with the aqueous acid solution at a temperature of 40 to 60°C.

13. The method according to any one of claims 1 to 12, further comprising neutralizing the aqueous layer with an aqueous alkaline solution in step (2).

14. 14. The method of claim 13, wherein the aqueous alkaline solution is calcium hydroxide.

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