Method for cleaning gases
A method for scrubbing volatile compounds using a collection solution with controlled solvent ratios and pH effectively captures and stabilizes volatile compounds, preventing duct clogging and leakage in reaction processes.
Patent Information
- Application Number
- JP2024101214
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-06-24
- Publication Date
- 2026-01-13
AI Technical Summary
The formation of solid compounds in reaction process ducts due to volatile compounds leads to duct clogging and potential leakage, posing risks to instrumentation and products.
A method involving bubbling a gas containing volatile compounds through a collection solution to dissolve and convert them into non-volatile compounds using an acidic or basic solution with specific solvent ratios and pH levels, effectively capturing and stabilizing volatile silicon compounds.
The method efficiently captures and converts volatile compounds into non-volatile forms, preventing duct clogging and leakage, ensuring safe and effective gas handling.
Smart Images
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Abstract
Description
[Technical Field]
[0001] The present invention relates to a method for cleaning gas in a reaction process using a volatile compound, for suppressing duct contamination by products derived from the volatile compound. [Background technology]
[0002] When raw materials and catalysts used in a reaction process are both volatile, the reaction site may be the exhaust duct wall. The formation of solid compounds in the duct can lead to duct clogging and have adverse effects on instrumentation and products. Furthermore, there is a risk that the compounds may disperse and leak outside the facility. Summary of the Invention [Problem to be solved by the invention]
[0003] The present invention aims to provide a method for scrubbing a gas containing a specific group of compounds that should be captured before entering an exhaust duct or other reaction site in order to prevent clogging of the duct, by passing the gas through a capturing solution. In particular, the present invention aims to provide a method for capturing volatile compounds before entering the exhaust duct or in the exhaust duct in a reaction process using highly volatile compounds, thereby suppressing undesired reactions in the exhaust duct.
[0004] The present inventors have investigated a method for this purpose, which involves bubbling a gas containing volatile compounds into a collection solution in a trap device to dissolve the volatile compounds. Furthermore, when the target compounds to be trapped are reactive under acidic or basic conditions, the present inventors have investigated a method for dissolving the volatile compounds in a collection solution and then rapidly converting them into non-volatile compounds, and have investigated the composition of the collection solution that enables this conversion. As a result of extensive investigations and research, the present inventors have succeeded in dissolving and trapping the volatile compounds in a collection solution without causing undesired reactions in the piping before and after the trap device, and in rapidly converting the volatile compounds dissolved in the collection solution into non-volatile compounds, thereby completing the present invention. [Means for solving the problem]
[0005] [1] A method for scrubbing a gas, comprising the step of passing a gas containing a specific group of compounds through an absorption solution to capture the specific group of compounds. [2] The gas cleaning method according to [1], wherein the specific compound group is a volatile silicon compound. [3] The method for cleaning gases according to [2], wherein the volatile silicon compound is an alkoxysilane, a silyl halide, or a hydrolyzate or condensation product thereof. [4] The method for scrubbing a gas according to any one of [1] to [3], wherein the collection solution contains water and a hydrophilic organic solvent and is acidic or basic. [5] The method for cleaning a gas according to [4], wherein the hydrophilic organic solvent is an alcohol solvent, an ether solvent, or a mixture thereof. [6] The gas cleaning method according to [5], wherein the hydrophilic organic solvent is methanol, ethanol, propanol, isopropyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, tetrahydrofuran, 1,4-dioxane, or a mixture thereof. [7] The method for scrubbing a gas according to [4], wherein the mass ratio of water to the hydrophilic organic solvent in the collection solution is 70 / 30 to 30 / 70. [8] The method for scrubbing a gas according to [5], wherein the mass ratio of water to the hydrophilic organic solvent in the collection solution is 70 / 30 to 30 / 70. [9] The method for scrubbing a gas according to [6], wherein the mass ratio of water to the hydrophilic organic solvent in the collection solution is 70 / 30 to 30 / 70.
[10] The method for scrubbing a gas according to any one of [4] to [9], wherein the pH of the collection solution is 0 to 6 when it is acidic, or 8 to 14 when it is basic.
[11] The method for scrubbing a gas according to any one of [4] to
[10] , wherein the collection solution contains an acidic compound, and the acidic compound is an organic acid compound, an inorganic acid compound, or a mixture thereof.
[12] The method for scrubbing a gas according to
[11] , wherein the acidic compound is hydrochloric acid, nitric acid, sulfuric acid, a carboxylic acid, a sulfonic acid, or a mixture thereof.
[13] The gas cleaning method according to
[11] , wherein the organic acid compound is acetic acid, propionic acid, acrylic acid, tolylsulfonic acid, trifluoromethanesulfonic acid, trifluoromethylbenzenesulfonic acid, or a mixture thereof.
[14] The method for scrubbing a gas according to any one of [4] to
[10] , wherein the collection solution contains a basic compound, and the basic compound is an organic basic compound, an inorganic basic compound, or a mixture thereof.
[15] The gas scrubbing method according to
[14] , wherein the basic compound is an amine compound, an alkali metal alkoxide, an alkali metal hydroxide, an alkaline earth metal hydroxide, or ammonia, or a mixture thereof.
[16] The gas scrubbing method according to
[14] or
[15] , wherein the basic compound is any one of trimethylamine, triethylamine, sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, or a mixture thereof.
[17] A method for producing a volatile silicon compound in a gas by using a collecting solution, and converting the silicon compound into a polysiloxane compound, the collection solution is a hydrophilic organic solvent containing water and contains an acidic compound or a basic compound; How to clean gas.
[18] A method for producing a volatile silicon compound in a gas by using a collecting solution, and converting the silicon compound into a polysiloxane compound, the collecting solution is a hydrophilic organic solvent containing water, the mass ratio of water to the hydrophilic organic solvent in the collecting solution is 70 / 30 to 30 / 70, and the pH of the collecting solution is 0 to 6 when acidic or 8 to 14 when basic; How to clean gas. [Effects of the Invention]
[0006] According to the gas washing method of the present invention, the volatile compounds can be quickly dissolved by passing a gas containing the volatile compounds through an absorption solution.
[0007] According to another aspect of the present invention, by preparing the absorption solution as an acidic or basic solution containing a certain amount of water and a hydrophilic organic solvent, it is possible to quickly dissolve the volatile compounds by passing a gas containing the volatile compounds through the absorption solution. In addition, the volatile compounds dissolved in the absorption solution are quickly converted into non-volatile compounds, and re-volatilization of the volatile compounds can be prevented. [Brief explanation of the drawings]
[0008] [Figure 1] FIG. 1 is a diagram showing an apparatus used in the gas cleaning method of the present example. DETAILED DESCRIPTION OF THE INVENTION
[0009] The present invention will be described in detail below, focusing on its preferred embodiments. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the present invention.
[0010] The present invention is a method for scrubbing a gas, which comprises a step of passing a gas containing a specific group of compounds through an absorption solution, thereby capturing the specific group of compounds.
[0011] <Target compounds to be captured> The target compounds for capture (specific compound group) in the present invention are not particularly limited as long as they are contained in gas, but a representative example that is preferred for capture is a volatile silicon compound. Among volatile silicon compounds, it is effective and more preferable to use alkoxysilanes such as tetraethoxysilane and methyltrimethoxysilane, and silyl halides such as tetrachlorosilane and chlorotrimethylsilane as target compounds for capture. The present invention is also suitable for capturing hydrolysates and condensation products of the above compounds (e.g., the alkoxysilanes and silyl halides).
[0012] <Conversion compounds> The target compound (specific compound group) is collected by passing a gas containing the compound through a collection solution. When the target compound is reactive under acidic or basic conditions, it is preferable to convert the volatile compound into a non-volatile compound quickly after dissolving in the collection solution. For example, when the target compound is a volatile silicon compound, it is preferable to convert the volatile silicon compound into a polysiloxane compound in the collection solution by passing a gas containing the volatile silicon compound through the collection solution. In the present application, the compound used to convert the target compound into a non-volatile compound is also referred to as a conversion compound. There are no particular limitations on the conversion compound as long as it is a compound that can be converted into a non-volatile compound, but examples include the "acidic compounds" and "basic compounds" described below.
[0013] <Organic solvents> In the present invention, the collection solution preferably contains an organic solvent. It is more preferable to use a hydrophilic organic solvent. Among these, alcohol-based solvents, ether-based solvents, or mixed solvents thereof are even more preferable. Examples of alcohol-based solvents include methanol, ethanol, propanol, isopropyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, and propylene glycol monomethyl ether, and examples of ether-based solvents include tetrahydrofuran and 1,4-dioxane. Alcohol-based solvents are particularly preferable, and can be easily used regardless of whether the target compound to be collected is hydrophilic or hydrophobic. The preferred range of the mass ratio of the hydrophilic organic solvent to water in the collection solution will be described later.
[0014] <Water> In the present invention, when the target compound to be captured is hydrolyzable, water is required to rapidly react with the target compound dissolved in the capturing solution. The mass ratio of water to the hydrophilic organic solvent in the capturing solution is preferably 70 / 30 to 30 / 70. The mass ratio is preferably determined appropriately depending on whether the target compound to be captured is hydrophilic or hydrophobic.
[0015] <pH of the collection solution> In the present invention, the collection solution is preferably acidic or basic. The collection solution preferably contains either an acidic compound or a basic compound. The pH of the collection solution is preferably 0 to 6 if it is acidic, and 8 to 14 if it is basic. To achieve both safety and versatility, it is more preferable to set the pH to 3 to 5 if it is acidic, and 9 to 11 if it is basic.
[0016] <Acidic compounds> The acidic compound can be used regardless of whether it is an organic acid compound or an inorganic acid compound, but is preferably an organic acid compound or an inorganic acid compound, or a mixture thereof.Among them, hydrochloric acid, nitric acid, sulfuric acid, carboxylic acid, sulfonic acid, or a mixture thereof is more preferred.Here, the carboxylic acid preferably includes acetic acid, propionic acid, or acrylic acid, and the sulfonic acid preferably includes tolylsulfonic acid, trifluoromethanesulfonic acid, or trifluoromethylbenzenesulfonic acid.
[0017] <Basic compounds> The basic compound may be either an organic basic compound or an inorganic basic compound, but is preferably an organic base, an inorganic base, or a mixture thereof. Among these, an amine compound, an alkali metal alkoxide, an alkali metal hydroxide, an alkaline earth metal hydroxide, ammonia, or a mixture thereof is preferred. Among these, trimethylamine, triethylamine, sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, or a mixture thereof is more preferred. From the viewpoint of safety in use, ammonia is particularly preferred.
[0018] <Collection solution composition> As described above, the mass ratio of water to the hydrophilic organic solvent in the collection solution is preferably 70 / 30 to 30 / 70, and the pH is preferably 0 to 6 if acidic and 8 to 14 if basic.
[0019] <Collection device> The structure of the trapping device is not particularly limited, but it is preferable to install it in the exhaust duct, and it is efficient to bubble the gas sent from the reactor by discharging it into the trapping solution. Spherical packing material that breaks down the bubbles into smaller particles can also be added to the device.
[0020] Conditions not specified in this application are not particularly limited as long as the object of the present invention can be achieved. [Example]
[0021] The present invention will be described in more detail below with reference to examples and comparative examples. Note that the following examples are provided for illustrative purposes and are not intended to limit the present invention in any way.
[0022] The following examples and comparative examples were carried out using the apparatus (experimental equipment) shown in Figure 1, with volatile silicon compounds as the target compounds for trapping, allowing for easy visual confirmation of trapping performance. In Figure 1, a two-necked recovery flask was used to simulate an industrial reactor. Volatile silicon compounds were placed in the recovery flask and stirred at 50°C using a magnetic stirrer. The recovery solution of the present invention was placed in the first trap stage. To confirm whether volatile silicon compounds were being sufficiently captured in the first trap stage, the recovery solution of Example 1 was also placed in the second trap stage. Nitrogen gas was introduced from the recovery flask side to generate bubbling of the recovery solution in each trap. When the volatilized silicon compounds dissolved in the recovery solution and reacted with water, nonvolatile polysiloxane compounds were produced, causing the solution to become cloudy. Cloudiness in the second trap stage indicates insufficient capture performance in the first trap stage.
[0023] Example 1 100 mL of tetraethoxysilane, the compound to be collected, was placed in a 300 mL two-necked recovery flask and stirred at 50°C for 12 hours. The collection solution used was propylene glycol monomethyl ether as the hydrophilic organic solvent, ammonia was added as a basic compound, the mass ratio of water to hydrophilic organic solvent (water / hydrophilic organic solvent ratio) was 41 / 59, and the pH was 10. Clouding was confirmed only on the first stage of the trap device, while the second stage of the trap device did not become cloudy.
[0024] Example 2 The same procedure as in Example 1 was carried out except that the compound to be collected was methoxytrimethylsilane. Only the first stage of the trap device was found to be cloudy, while the second stage of the trap device was not.
[0025] Example 3 The same procedure as in Example 1 was carried out except that the basic compound was sodium hydroxide and the collection solution had a pH of 11. White turbidity was observed only on the first stage of the trap device, but not on the second stage of the trap device.
[0026] Example 4 The same procedure as in Example 1 was carried out, except that the hydrophilic organic solvent was ethanol, the basic compound was sodium ethoxide, and the collection solution used had a pH of 11. Clouding was observed only on the first stage of the trap device, and not on the second stage of the trap device.
[0027] Example 5 The same procedure as in Example 1 was carried out, except that acetic acid was used as the acidic compound instead of the basic compound, and a collection solution with a pH of 3 was used. Clouding was confirmed only in the first stage of the trap device, and not in the second stage of the trap device.
[0028] Example 6 The same procedure as in Example 1 was carried out except that the water / hydrophilic organic solvent ratio was set to 33 / 67. White turbidity was observed only on the first stage of the trap device, but not on the second stage of the trap device.
[0029] Example 7 The same procedure as in Example 1 was carried out except that the hydrophilic organic solvent was ethanol and the water / hydrophilic organic solvent ratio was 47 / 53. Clouding was observed only on the first stage of the trap device, but not on the second stage of the trap device.
[0030] Example 8 The same procedure as in Example 1 was carried out except that the hydrophilic organic solvent was changed to isopropyl alcohol. Clouding was observed only on the first stage of the trap device, but not on the second stage of the trap device.
[0031] Example 9 The same procedure as in Example 1 was carried out, except that the compound to be trapped was chlorotrimethylsilane, the hydrophilic organic solvent was tetrahydrofuran, and the water / hydrophilic organic solvent ratio was 50 / 50. Clouding was observed only on the first stage of the trap device, and not on the second stage of the trap device.
[0032] Example 10 Trapping using a tetraethoxysilane reaction solution was carried out as follows. 10 g of tetraethoxysilane, 5 g of 25% aqueous ammonia, and 50 g of isopropyl alcohol were placed in a 300 mL two-necked recovery flask and reacted at 50°C for 12 hours. The tetraethoxysilane that volatilized during the reaction was collected. The same trapping solution as in Example 1 was used. Clouding was observed only on the first stage of the trap device, but not on the second stage.
[0033] (Comparative Example 1) The same procedure as in Example 1 was carried out, except that the water / hydrophilic organic solvent ratio was 12 / 88. Although the solution was homogeneous overall, cloudiness was observed on both the first and second stages of the trapping device. This suggested that insufficient reactivity was due to a lack of water.
[0034] (Comparative Example 2) The same procedure as in Example 1 was carried out, except that the water / hydrophilic organic solvent ratio was set to 74 / 26. The collected solution separated into two layers, and slight cloudiness was observed on both the first and second stages of the trap device.
[0035] Table 1 shows the conditions and collection performance of the examples and comparative examples. ○: Only the first stage of the trap device becomes cloudy, the second stage does not become cloudy. ×: The second stage of the trap device becomes cloudy. This means that...
[0036] [Table 1] [Industrial Applicability]
[0037] According to the present invention, in a reaction process using a volatile compound, duct contamination by products derived from the volatile compound can be suppressed, and therefore the present invention can be applied to any field that includes the reaction process in its manufacturing process, and therefore can be used in a wide variety of industries (for example, the automobile industry, electronics and electrical industry, communications industry, information equipment industry, chemicals industry, pharmaceutical industry, space industry, military industry, etc.).
Claims
1. A method for cleaning a gas, comprising the step of passing a gas containing a specific group of compounds through a collection solution, thereby collecting the specific group of compounds.
2. 2. The gas cleaning method according to claim 1, wherein said specific compound group is a volatile silicon compound.
3. 3. The method for cleaning gases according to claim 2, wherein the volatile silicon compound is an alkoxysilane, a silyl halide, or a hydrolyzate or condensation product thereof.
4. 4. The method for scrubbing a gas according to claim 1, wherein the collection solution contains water and a hydrophilic organic solvent and is acidic or basic.
5. 5. The method for cleaning gases according to claim 4, wherein the hydrophilic organic solvent is an alcohol solvent, an ether solvent, or a mixture thereof.
6. 6. The gas cleaning method according to claim 5, wherein the hydrophilic organic solvent is methanol, ethanol, propanol, isopropyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, tetrahydrofuran, 1,4-dioxane, or a mixture thereof.
7. 5. The method for scrubbing a gas according to claim 4, wherein the mass ratio of water to the hydrophilic organic solvent in the collection solution is 70 / 30 to 30 / 70.
8. 6. The method for scrubbing a gas according to claim 5, wherein the mass ratio of water to the hydrophilic organic solvent in the collection solution is 70 / 30 to 30 / 70.
9. 7. The method for scrubbing a gas according to claim 6, wherein the mass ratio of water to the hydrophilic organic solvent in the collection solution is 70 / 30 to 30 / 70.
10. 5. The gas scrubbing method according to claim 4, wherein the pH of the collecting solution is 0 to 6 when it is acidic, or 8 to 14 when it is basic.
11. 5. The method for scrubbing a gas according to claim 4, wherein the collection solution contains an acidic compound, and the acidic compound is an organic acid compound, an inorganic acid compound, or a mixture thereof.
12. 12. The method of claim 11, wherein the acidic compound is hydrochloric acid, nitric acid, sulfuric acid, a carboxylic acid, or a sulfonic acid, or a mixture thereof.
13. 12. The method for cleaning gases according to claim 11, wherein the organic acid compound is acetic acid, propionic acid, acrylic acid, tolylsulfonic acid, trifluoromethanesulfonic acid, trifluoromethylbenzenesulfonic acid, or a mixture thereof.
14. 5. The method for scrubbing a gas according to claim 4, wherein the collection solution contains a basic compound, and the basic compound is an organic basic compound, an inorganic basic compound, or a mixture thereof.
15. 15. The method for cleaning a gas according to claim 14, wherein the basic compound is an amine compound, an alkali metal alkoxide, an alkali metal hydroxide, an alkaline earth metal hydroxide, or ammonia, or a mixture thereof.
16. 15. The gas scrubbing method according to claim 14, wherein the basic compound is any one of trimethylamine, triethylamine, sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, or a mixture thereof.
17. The method includes a step of collecting volatile silicon compounds from the gas in a collection solution and converting them into polysiloxane compounds, the collection solution is a hydrophilic organic solvent containing water and contains an acidic compound or a basic compound; How to clean gas.
18. The method includes a step of collecting volatile silicon compounds from the gas in a collection solution and converting them into polysiloxane compounds, the collecting solution is a hydrophilic organic solvent containing water, the mass ratio of water to the hydrophilic organic solvent in the collecting solution is 70 / 30 to 30 / 70, and the pH of the collecting solution is 0 to 6 when acidic or 8 to 14 when basic; How to clean gas.