JPS5910655B2 - Di-2-anthraquinonyl ether tetrasulfonic acid and its salts, processes for their production, and redox agents for wet desulfurization processes using them - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to di-2-anthraquinonyl ether tetrasulfonic acids and salts thereof, processes for their production and their use in wet desulfurization processes.

Although di-2-anthraquinonyl ether has been known, its sulfonated product is not known.

The present inventors newly synthesized di-2-anthraquinonyl ether tetrasulfonic acid and examined a wet desulfurization process using this product. We have discovered that it is an extremely effective redox agent for processes, and have completed the present invention.

The novel G2-anthraquino of the present invention? 1-tertetrasulfonic acid and its salts have the formula (I) (wherein M means a hydrogen atom, a sodium atom, a potassium atom or an ammonium group.

) is a compound represented by G above 2
-Anthraquinonyl ether One of the methods for producing tetrasulfonic acid is to sulfonate di-2-anthraquinonyl ether by heating with a sulfonating agent.

The starting material here, di-2-anthraquinonyl ether, is described in the Journal of Chemical Society.
Y), 1923, p. 3032, by heating and condensing 2-chloroanthraquinone and 2-hydroxyanthraquinone at 230 to 260°C in the presence of sodium acetate and copper powder.

Another method for producing the di-2-anthraquinonyl ether tetrasulfo derivative of the present invention is 4,4'-bis(2
-carboxybenzoyl) diphenyl ether is heat-treated with a dehydration condensation agent and a sulfonating agent. The starting material, 4.l-bis(2-carboxybenzoyl)diphenyl ether, can be obtained by a Friedel-Crafts reaction between 2 molar ratios of anhydrous diphenyl ether and 1 molar ratio of diphenyl ether. I can do it.

A method of heat-treating the sulfonating agent or 4,4'-bis(2-carboxybenzoyl) diphenyl ether used in the sulfonation of di-2-anthraquinonyl ether with a dehydration condensation agent and a sulfonating agent in the present invention As the dehydration condensation agent used for this purpose, fuming sulfuric acid is commercially most advantageous.

In addition, in these cases, it is possible to carry out the reaction in an inert solvent such as liquefied sulfurous acid or halogenated hydrocarbon solvent, but usually the dehydration condensing agent and/or sulfonating agent is directly used in the solvent. It is preferable to serve as both. When producing di-2-anthraquinonyl ether tetrasulfonic acid of formula (1) using di-2-anthraquinonyl ether as a raw material, after charging di-2-anthraquinonyl ether into fuming sulfuric acid. , heated to 70-200℃, 3-
The reaction is carried out for 20 hours, preferably at 100 to 180°C for 4 to 10 hours.

The fuming sulfuric acid used at this time has a free SO3 concentration of 0 to 80.
%, preferably 5 to 60%, and the amount used is free S based on di-2-anthraquinonyl ether as the raw material.
The O3/4 molar ratio is greater than or equal to O3/4 molar ratio. The upper limit of the amount to be used is not particularly limited, but it is usually preferable to use it within a range of 4 to 10 molar ratios. The end point of the reaction can be determined, for example, by subjecting the reaction solution to thin layer chromatography (thin layer plate: Tokyo Kasei Co., Ltd. spot film silica gel 1f, developing solution: n-butanol-ethanol: %N
- aqueous ammonia = 6:2:3 (volume ratio)). On the other hand, in the method for producing di-2-anthraquinonyl ether tetrasulfonic acid of the present invention using 4,4-bis(2-carboxybenzoino(he)diphenyl ether as a raw material), it acts as both a dehydration condensation agent and a sulfonating agent. Fuming sulfuric acid is used.

In this case, the fuming sulfuric acid used has a free SO3 concentration of 0 to 80%, preferably 5 to 60%. In the case of fuming sulfuric acid with a free SO3 concentration exceeding 80%, it becomes difficult to handle industrially and impurities are likely to be produced as by-products during the reaction. The amount of fuming sulfuric acid used varies depending on the concentration of free SO3 contained, but the amount of fuming sulfuric acid used should be at least 6 molar ratios of free SO3 to 4,4'-bis(2-carboxybenzoyl) diphenyl ether as a raw material. It is preferable to use ~ Specifically, 10 parts of 4.4/-bis(2-carboxybenzoyl) diphenyl ether (parts means parts by weight).

5 to 100 parts of fuming sulfuric acid is used. For convenience of reaction operation, it is particularly preferable to use the amount in the range of 20 to 70 parts. The reaction was carried out in the above fuming sulfuric acid with 4,4'-
Add bis(2-carboxybenzoyl)diphenyl ether and gradually raise the temperature while stirring to a temperature of 100 to 200
C. for 1 to 50 hours, preferably 2 to 20 hours. The end point of the reaction can be easily determined by means such as thin layer chromatography of the reaction solution. Ji 2
- Method using anthraquinonyl ether as raw material and 4.
In any of the methods using l-bis(2-carboxybenzoyl) diphenyl ether as a raw material, an alkali metal sulfate such as sodium sulfate or potassium sulfate is added to prevent the oxidation of the anthraquinone nucleus during the reaction. Good too.

To separate the target product from the reaction solution, after the reaction is complete, dilute the reaction solution with water and add di-2-anthraquinonyl ether tetrasulfonic acid and approximately the same amount of alkali metal hydroxide, ammonium hydroxide, and alkali. After adding metal salt or ammonium salt, neutralize by adding calcium carbonate or lime,
The desired salt of di-2-anthraquinoninolether tetrasulfonic acid is obtained by removing the produced gypsum and evaporating the obtained slurry to dryness.

Examples of the alkali metal hydroxide, alkali metal salt or ammonium salt include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium sulfate, potassium sulfate, ammonium carbonate and ammonium sulfate. In order to separate the target product from the reaction solution, salting out by adding an alkali metal salt or ammonium salt to the reaction solution diluted with water, or salting out the reaction solution diluted with water with an alkali metal hydroxide or hydroxide. It is also possible to use a salting-out method that involves partial neutralization with ammonium).

Furthermore, after diluting the reaction solution with water and adding an alkali metal hydroxide, ammonium hydroxide, alkali metal salt, or ammonium salt in an amount equivalent to di-2-anthraquinonyl ether tetrasulfonyl ether, a large amount of water-soluble It is also possible to use a method in which the salt of di-2-anthraquinonyl ether tetrasulfonic acid is precipitated by pouring it into an organic solvent such as methanol or acetone, and then collecting it in a large quantity. The salt of di-2-anthraquinonyl ether tetrasulfonic acid of the present invention obtained as described above is a yellow to brown powdery solid that does not have a clear melting point and decomposes when heated. .

As described in Example 1, elemental analysis, infrared absorption spectrum and proton NMR spectrum revealed that this di-2-anthraquinonyl ether tetrasulfonic acid salt had the formula (1
), two of the four sulfonic acid groups are 3.3 grains, and the other two sulfonic acid groups are 6.6 grains, 6.7 grains, or 7 grains. - It is estimated that it has a structure in which it is bonded at the τ position, and there is also a possibility that it is a mixture of these positional isomers. Di-2-anthraquinonyl ether tetrasulfonic acid represented by formula (1) and its salts are easily soluble in water, and therefore exhibit relatively high solubility even in concentrated aqueous inorganic salt solutions.

Concentrated aqueous solutions of sodium thiosulfate or sodium thiocyanate for sodium 2.7-anthraquinone disulfonate and sodium di-2-anthraquinonyl ether tetrasulfonate of the present invention, as well as sodium sulfate, sodium thiosulfate and sodium thiocyanate. The table shows the results of measuring solubility in mixed aqueous solutions.
1.

As is clear from Table 1, sodium di-2-anthraquinonyl ether tetrasulfonate represented by formula (l) is known to be easily soluble in water among anthraquinone disulfonates. It shows almost the same solubility as sodium 7-anthraquinone disulfonate in aqueous inorganic salt solutions.

As will be described later, when anthraquinone is disulfonated, 2,7-anthraquinone disulfonic acid, which is easily soluble in water, and 2,6-anthraquinone, which has a relatively low solubility in water, are used.
- Approximately equal amounts of anthraquinone disulfonic acid are produced. On the other hand, in the case of di-2-anthraquinone disulfonic acid, it has a structure in which two molecules of anthraquinone disulfonic acid are ether-bonded with an oxygen atom, and as mentioned above, it is a mixture of several positional isomers. One of the characteristics of the present invention is that, despite the possibility, no components that are difficult to dissolve in water are found, and all of the obtained di-2-anthraquinonyl ether tetrasulfonic acid is highly soluble in water. be. Di-2-anthraquinonyl ether tetrasulfonic acid &A represented by formula (I) also has a reversible redox property characteristic of quinone compounds.

That is, di-12-anthraquinonyl ether tetrasulfo A is reduced by, for example, sodium vanadate to form a leuco form, and the leuco form is oxidized by, for example, oxygen in the air and returns to a quinone form. Ji 2 -
In the case of sodium 2,7-anthraquinone disulfonate, the rate at which anthraquinonyl ether tetrasulfonic acid was reduced and the rate at which the leuco form thus produced was oxidized by air was measured. A comparison is shown in Table 2. Table 2 also lists the standard redox potentials of sodium 2.7-anthraquinone disulfonate and sodium di-2-anthraquinonyl ether tetrasulfonate. As is clear from Table 2, there is almost no difference in the redox reaction rate and standard redox potential between sodium di-2-anthraquinonyl ether tetrasulfonate and sodium 2,7-anthraquinone disulfonate. The compounds have very similar properties regarding redox reactions.

Further, the sodium di-12-anthraquinonyl ether tetrasulfonamide of the present invention is characterized in that the two anthraquinone nuclei in its molecule exhibit redox reactions independently. Therefore, as will be described later, when this substance is used as a redox agent in a wet desulfurization process, it is sufficient to use the amount in a molar ratio of the usual amount of sodium 2,7-anthraquinone disulfonate. . Di-2-anthraquinone disulfonic acid has uses as an intermediate for dyes and pharmaceuticals, has high solubility in water, and has properties related to redox reactions that are similar to 2,7-anthraquinone disulfonic acid. This makes it extremely useful as a redox agent in wet desulfurization processes. The wet desulfurization process here refers to petroleum gas, coal gas, or liquid hydrocarbons containing hydrogen sulfide being brought into contact with a liquid containing a redox agent that can be reversibly redoxed to oxidize hydrogen sulfide and convert it into a simple substance. On the other hand, the redox agent, which has been reduced by oxidizing hydrogen sulfide, is brought into contact with air, oxidized, and regenerated, and is again used to oxidize hydrogen sulfide. It is a cyclical process.

In the wet desulfurization process mentioned above, especially in the process called Stretchford Process (StretfOrdPrOcess), one or several anthraquinone disulfonic acids or salts thereof, or these and two valent A metal compound, preferably a vanadate salt such as sodium metavanadate, and optionally a chelating agent such as potassium sodium tartrate or ethylenediaminetetraacetate are used as an alkaline aqueous solution.

The most practical embodiment of this process is
When anthraquinone disulfonic acid and sodium metavanadate are used as redox agents in an alkaline aqueous solution, the following reaction is said to occur (Aromatics, Vol. 19, p. 53 (1967), Nippon Aromatics, Inc. (Published by the Family Industry Association). In the formula, ADA represents anthraquinone disulfonic acid, and ADAX represents the leuco form of anthraquinone disulfonic acid. As is clear from the above equation, anthraquinone disulfonic acid participates in the oxidation of hydrogen sulfide to elemental sulfur together with sodium metavanadate in the stress food process, and is itself reduced to the leuco form, which is then brought into contact with air. It is oxidized and regenerated to the original anthraquinone disulfonic acid.

Conventionally, anthraquinone disulfonic acid for the stress food process is 1, 6-1, 7-1, or 2-
・It is known that 7-anthraquinone disulfonic acid is effective, but for actual use it requires high water solubility and the possibility of being industrially available at low cost. However, the only one that can be used practically is 2,7-anthraquinone disulfonic acid. Therefore, there are serious problems as follows. That is, when anthraquinone is disulfonated to produce this 2,7-anthraquinone disulfo 4, approximately equal amounts of 2,6- and 2,7-anthraquinone disulfonic acids are produced, and a mixture thereof is obtained. .

However, 2,6-anthraquinone disulfonic acid is difficult to dissolve in the alkaline aqueous solution used in the strain food process, so it is difficult to use it in the process. Therefore, if there is no beneficial use for 2,6-anthraquinone disulfonic acid, 2.
- It becomes extremely difficult to supply 7-anthraquinone disulfonic acid at a low cost. The above problem is solved by using di-2-2- represented by formula (1) instead of anthraquinone disulfonic acid.
A solution can be achieved by using anthraquinonyl ether tetrasulfonic acid alone or in admixture with anthraquinone disulfonic acid.

As mentioned above, di-2-anthraquinonyl ether tetrasulfonic acid represented by formula (1) has excellent water solubility and has properties related to redox reactions that are extremely similar to 2,7-anthraquinone disulfonic acid. In addition, when used in the strain food process, it exhibits the same reaction behavior as 2,7-anthraquinone disulfide, and not only works effectively to oxidize hydrogen sulfide and remove it as elemental sulfur. , can provide several advantages not seen when using 2,7-anthraquinone disulfonic acid.

When di-2-anthraquinone disulfonic acid is used in place of anthraquinone disulfonic acid in the strain food process, simply add some or all of the anthraquinone disulfonic acid in an alkaline aqueous solution to a molar ratio of It is sufficient to replace it with di-2-anthraquinonyl ether tetrasulfonic acid, and there is no need to change the composition of the other alkaline aqueous solution or the liquid properties such as pH.

Therefore, when di-2-anthraquinonyl ether tetrasulfonic acid is used, di-2-anthraquinonyl ether tetrasulfonic acid or di-2-anthraquinonyl ether tetrasulfonic acid and anthraquinone disulfonyl ester are used. An aqueous solution containing about 0.5% or more of the mixture is prepared, and a base such as ammonia or an alkali metal carbonate is added to this to form an alkaline aqueous solution having a pH of 7 or more, preferably 8.5 to 9.5.・Used for processes.

In addition, a metal compound having two or more valence states, such as sodium metavanadate, is preferably 1/100
It is preferably contained in an alkaline aqueous solution at a concentration of 0 to 1/20 mol/l, and if necessary, a chelating agent such as potassium sodium tartrate or ethylenediaminetetraacetate can also be used in combination. When di-2-anthraquinonyl ether tetrasulfonic acid is used in place of anthraquinone disulfonic acid, the following advantages can be mentioned. When producing 2,7-anthraquinone disulfonic acid, approximately the same amount of 2,6-anthraquinone disulfozoic acid, which is difficult to use in the stretch food process due to its poor solubility, is produced. Di-2-anthraquinonyl ether tetrasulfonic acid does not contain isomers that are poorly soluble in water; all of them are highly soluble in water, and all of them can be used in the strain food process.

On the other hand, di-2-anthraquinonyl ether tetrasulfonic acid is used under the same conditions as 2,7-anthraquinone disulfonic acid because its redox reaction properties are very similar to those of 2,7-anthraquinone disulfonic acid. be able to.

Therefore, there is an advantage that equipment that has conventionally used 2,7-anthraquinone disulfonic acid can be used as is, without changing the operating conditions of the process or modifying the equipment. The present invention will be explained below with reference to Examples, but the present invention is not limited thereto.

In the text, "parts" and "%" mean "parts by weight" and [% by weight]. Example 1 10 parts of anhydrous sodium sulfate in 100 parts of 30% oleum,
7 parts and 4,4'-bis(2-carboxybenzoino(
c) Add 23.3 parts of diphenyl ether and raise the temperature to 160°C over 2 hours while stirring.
The reaction was carried out at ℃ for 12 hours.

After cooling to room temperature, the mixture was poured into 200 parts of water, and 6 parts of caustic soda was added with stirring. Thereafter, while maintaining the temperature at 70 to 80°C, calcium carbonate was added until the mixture became neutral to precipitate gypsum. This was then filtered and the slurry was spray dried to obtain 49 parts of a tan powder. This substance does not have a clear melting point and decomposes when heated.

Its infrared absorption spectrum (KBr tablet method) includes the figure-
As shown in 1, absorption based on C=O of anthraquinone nucleus (near 1690CfILm1), absorption based on benzene nucleus (near 1590CTfLm1), and absorption based on sulfonic acid group (near 1220cm-1) are observed,
Also, proton NMR spectrum of this product (solvent DMSO
-D6, room temperature) showed the absorption pattern shown in FIG.
Furthermore, the elemental analysis value of the yellowish brown powder obtained in this example purified by methanol extraction has the composition of formula (1) (
The value was close to the calculated value based on C28HlOOl7S4Na4).

According to the elemental analysis values, this product is considered to be sodium di-2-anthraquinonyl ether tetrasulfonate represented by the formula ().

Example 2 7.1 parts of anhydrous sodium sulfate in 128 parts of 25% oleum
1 part and 23.3 parts of 4,4'-bis(2-carboxybenzoyl)diphenyl ether were added, and the temperature was raised to 170°C over about 2 hours while stirring.

After reacting at the same temperature for 8 hours, cool to room temperature and add 30 ml of water.
It was discharged into 0 parts. Add 8 parts of caustic soda to 70-80%
While maintaining the temperature at °C, calcium carbonate was gradually added until the mixture became neutral to precipitate gypsum.

Next, the solution was filtered through plaster, and the resulting solution was spray-dried to obtain 49.2 parts of sodium di-2-anthraquinonyl diphenyl ether tetrasulfonyl ether. This product has an infrared absorption spectrum similar to that obtained in Example 1 and a proton N
The MR spectrum is shown. Example 3 8.7 parts of anhydrous potassium sulfate and 23.3 parts of 4-Ebis(2-carboxybenzoyl) diphenyl ether were added to 72 parts of 50% fuming sulfuric acid, and the temperature was raised to 170°C over 3 hours while stirring. .

After reacting at the same temperature for 10 hours, it was cooled to room temperature, and 3
It was discharged into 00 copies. Add 8.4 parts of caustic potash to 70-8
While maintaining the temperature at 0°C, calcium hydroxide was gradually added until the mixture became neutral to precipitate gypsum. Next, this was thoroughly filtered, and the solution ▲ was spray-dried to obtain 51.8 parts of potassium di-2-anthraquinonyl ether tetrasulfonate.
Example 4 7.1 parts of anhydrous sodium sulfate and 21.5 parts of 2,2'-dianthraquinonyl ether in 80 parts of 25% oleum.
of the mixture was added, and the temperature was raised to 155°C over 2 hours while stirring.

The sulfonation reaction was carried out by keeping at 155-160°C for 5 hours.

After the reaction, it was cooled to room temperature and then discharged into 300 parts of water.
6 parts of caustic soda were added. Then, while maintaining the temperature at 70 to 80°C, calcium carbonate was added until the mixture became neutral to precipitate gypsum.

Next, this was separated and the slurry was spray-dried to obtain 47% sodium di-2-anthraquinonyl ether tetrasulfonate.
I got the department. This product showed the same infrared absorption spectrum and proton NMR spectrum as those obtained in Example 1.

Example 5 Glass tube with inner diameter 10 CITL 1 length 100 (:IIL)
Made of polypropylene with diameter 1 (1177 mm) inside (with jacket)
! Turnip type filler (Teraretsu S type) with a height of 95cfn
A hydrogen sulfide-containing gas containing 5 V/N of hydrogen sulfide in a gas consisting of 6% carbon dioxide and 94% nitrogen was fed at a rate of 2301/Ht- from the bottom of the absorption tower, which was filled up to 100%.

On the other hand, 0.03 ml of sodium metavanadate was extracted from the upper part of the tower.
A 40°C alkaline aqueous solution containing 0.0025 mol/l of sodium di-2-anthraquinonyl ether tetrasulfonate and 0.0025 mol/l of sodium di-2-anthraquinonyl ether tetrasulfonate and adjusted to pH 9 by adding sodium carbonate was heated at a rate of 4.6e/Hr. The mixture was sprayed with water and brought into contact with hydrogen sulfide-containing gas. The gas-liquid ratio is 0.02.
The liquid was extracted from the bottom of the absorption tower, and the inner diameter was 10 CIIL.
Maximum 100c! The mixture was sent to a regeneration tower made of a glass tube (with a jacket), and air was blown into it to completely precipitate the sulfur. The residence time of the liquid in the regeneration tower was 20 minutes. By treating the hydrogen sulfide-containing gas as described above, hydrogen sulfide in the hydrogen sulfide-containing gas could be removed with a desulfurization rate of 99.8% or more.

In addition, sodium 2,7-anthraquinone disulfonate was used instead of sodium di-2-anthraquinonyl ether tetrasulfonate, and the concentration of sodium 2,7-anthraquinone disulfonate was 0.005 mol/l. When hydrogen sulfide-containing gas was treated in the same manner as above, the desulfurization rate was 99.6%.

[Brief explanation of the drawing]

Figure 1 shows the infrared absorption spectrum of sodium di-2-anthraquinonyl ether tetrasulfonate.

Claims (1)

[Claims] 1 Formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, M means a hydrogen atom, a sodium atom, a potassium atom or an ammonium group.) 2-Anthraquinonyl ether tetrasulfonic acid or a salt thereof. 2 Formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ Formula (I) ▲Mathematical formula, which is characterized by sulfonating di-2-anthraquinonyl ether by heating with fuming sulfuric acid. There are chemical formulas, tables, etc. ▼ (In the formula, M represents a hydrogen atom, a sodium atom, a potassium atom, or an ammonium group.) Process for producing di-2-anthraquinonyl ether tetrasulfonic acid or its salt . 3 4・4'
-Formula (I) characterized by heating bis(2-carboxybenzoyl) diphenyl ether with fuming sulfuric acid to dehydrate, ring-close and sulfonate ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, M is a hydrogen atom, A method for producing di-2-anthraquinonyl ether tetrasulfonic acid or a salt thereof, which is represented by a sodium atom, a potassium atom, or an ammonium group. 4 Formula ( I
) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, M represents a hydrogen atom, a sodium atom, a potassium atom, or an ammonium group.) Di-2-anthraquinonyl ether tetrasulfonic acid or its Redox agent for wet desulfurization processes involving salt. 5. The redox agent according to claim 4, wherein the wet desulfurization process is a strain food process.