JPS6252606B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for desulfurizing hydrogen sulfide-containing gas. Specifically, the present invention relates to a desulfurization method by contacting a hydrogen sulfide-containing gas with an alkaline aqueous solution consisting of hydroxyanthraquinone sulfonic acid, a variable valence metal compound, and a carbonate. Conventionally, an alkaline aqueous solution consisting of one or more anthraquinone sulfonic acids and their salts, variable valence metal compounds, and carbonates is brought into contact with refinery gas, coke oven gas, and various other gases for cleaning. The method for removing hydrogen sulfide contained in
37-14054 and 37-17829). It is said that all isomers of anthraquinone disulfonic acid used in this method are effective, but
Regarding the reaction rate with hydrogen sulfide, anthraquinone-2,7-disulfonic acid, anthraquinone-
2,6-disulfonic acid, followed by other anthraquinone disulfonic acids; on the other hand, anthraquinone-2,7-disulfonic acid has the highest solubility in water, and anthraquinone-2,6-disulfonic acid has the lowest solubility in water. Therefore, among the anthraquinone disulfonic acid isomers used in this method, anthraquinone-2,7-disulfonic acid is particularly effective. Generally, anthraquinone disulfonic acid and its salts are produced by reacting anthraquinone with sulfuric anhydride or fuming sulfuric acid to sulfonate it, but in the case of anthraquinone-2,7-disulfonic acid, approximately It is customary for an equal amount of anthraquinone-2,6-disulfonic acid to be produced as a by-product (Helvetica Chimica Acta 10 , 219).
Therefore, when producing anthraquinone-2,7-disulfonic acid and using it as a hydrogen sulfide removal agent in the strep hood method, it is difficult to effectively utilize the by-product anthraquinone-2,6-disulfonic acid. If this is not possible, costs will inevitably increase. As mentioned above, the present invention was made in order to effectively utilize anthraquinone-2,6-disulfonic acid, which has had almost no use other than a small amount of use as a dye. - By converting 6-disulfonic acid into oxyanthraquinone sulfonic acid, its solubility in water is increased and it is used as a hydrogen sulfide removal agent in the strain food method. Therefore, in the method for desulfurizing a hydrogen sulfide-containing gas according to the present invention, the hydrogen sulfide-containing gas is (In the formula, m and n are integers of 1 to 4, and M represents H, NH ₄ or an alkali metal.) An alkaline aqueous solution consisting of a hydroxyanthraquinone sulfonic acid, a variable valence metal compound, and a carbonate. This is carried out by contacting the aqueous solution with hydrogen sulfide to absorb the hydrogen sulfide into the aqueous solution. General formula used in the present invention (However, in the formula, m and n are integers of 1 to 4, and M represents H, NH ₄ or an alkali metal.) As the hydroxyanthraquinone sulfonic acid, for example, 2-hydroxyanthraquinone-6-sulfone acid, 2-hydroxyanthraquinone-3,6-disulfonic acid, 2,6-dihydroxyanthraquinone-3-sulfonic acid, 2.
6-dihydroxyanthraquinone-3・7-disulfonic acid, 2-hydroxyanthraquinone-4・
5,6-trisulfonic acid, 2-hydroxyanthraquinone-1,6,8-trisulfonic acid, 2,6
-dihydroxyanthraquinone-4-sulfonic acid, 2,6-dihydroxyanthraquinone-4.
8-disulfonic acid, 2,6-dihydroxyanthraquinone-4,5-disulfonic acid, 1,2,6-
Trihydroxyanthraquinone-5-sulfonic acid, 2,6-dihydroxyanthraquinone-1.
5-disulfonic acid, 1,2,6-trihydroxyanthraquinone-5-sulfonic acid, 1,2,6-
trihydroxyanthraquinone-4,5-disulfonic acid, 1,2,6-trihydroxyanthraquinone-4,5-disulfonic acid, 1,2,6-trihydroxyanthraquinone-3-sulfonic acid,
1,2,6-trihydroxyanthraquinone-
There are 3,7-disulfonic acids and their lithium, sodium, potassium and ammonium salts. Hydroxyanthraquinone sulfonic acid having general formula I is produced as follows. That is, anthraquinone-2,6-disulfonic acid or a salt thereof (e.g. lithium salt, sodium salt,
2- by melting potassium salt, ammonium salt) and an alkali metal hydroxide or an alkaline earth metal oxide or hydroxide in an aqueous solvent.
Hydroxyanthraquinone-6-sulfonic acid or a salt thereof, 2,6-dihydroxyanthraquinone or 1,2,6-trihydroxyanthraquinone can be obtained alone or as a mixture. This melting reaction is usually carried out by a known method [Dictionary of Applied Chemistry (Fourth
Edition), Grundlagen Der Synthese Von
Zwischenprodukten Und Farbstoffen, Large Organic Chemistry (Aromatic Compounds), etc.]. Then, the above compound is treated with sulfuric anhydride or fuming sulfuric acid to a concentration of 50 to 180 ml without a catalyst or in the presence of a metal such as mercury, palladium, platinum, or rhodium or a salt thereof if necessary.
°C, preferably at a temperature of 80-150 °C for 0.5-8 hours,
Hydroxyanthraquinone sulfonic acid having 1 to 4 sulfonic groups or a salt thereof is produced by carrying out the sulfonation reaction preferably for 1 to 3 hours. In this case, when using fuming sulfuric acid,
1 to 65% oleum is preferred, particularly 5 to 30% oleum. It has been found that the solubility of the thus obtained hydroxyanthraquinone sulfonic acid and its salt in water is higher than that of the starting material, anthraquinone-2,6-disulfonate. As described above, anthraquinone-2,6-disulfonates have the disadvantage that they are unsuitable as hydrogen sulfide removal agents in the strain food method because they do not have adequate solubility in water. By leading to hydroxyanthraquinone sulfonic acid or a salt thereof having the general formula used in , the solubility in water is improved. Further economic advantage can be achieved by using it in combination with disulfonic acid or a salt thereof. Hydroxyanthraquinone sulfonic acid having the above general formula is used in the form of an aqueous solution of sodium, potassium, lithium, or ammonia, and its concentration is usually 0.001 to 0.05 mol/, preferably 0.002 to 0.03 mol/. In the present invention, a variable valence metal compound is used as a catalyst in order to maintain good activity of hydroxyanthraquinone sulfonic acid used as a desulfurization agent. Typical examples of variable valence metals include iron, chromium, manganese, vanadium, copper, cobalt, and nickel. Generally, metal salts, metal acid salts, complex salts, chelate compounds, etc. are used. Particularly specific examples include sodium iron oxide, ferrous thiocyanate, ferric thiocyanate, sodium ammonium ferricyanide, ammonium ferrocyanide, ammonium ferricyanide, sodium ferricyanide, sodium ferrocyanide, potassium ferricyanide, Potassium erocyanide, sodium potassium ferricyanide, iron-ethylenediaminetetraacetic acid (hereinafter abbreviated as -EDTA), manganese sulfate (), manga () ammonium sulfate,
Manganese chloride (), ammonium, sodium, potassium, calcium and barium salts of permanganate, ammonium, sodium and potassium salts of manganic acid, potassium hexacyanomanganate (), manganese acetate, manganese acetylacetone, manganese-EDTA, sodium vanadate , ammonium metavanadate, potassium metavanadate, vanadium sulfate, vanadyl sulfate, vanadium chloride, vanadyl chloride, copper sulfate, potassium tetracyanocorate, copper thiocyanate, copper phthalocyanine, copper-EDTA, copper acetylacetone, hexacyanocuprate Potassium, ammonium, sodium and potassium salts of chromic acid, ammonium, sodium and potassium salts of dichromate, ammonium tetrathiocyanate diamine chromate, chromium-EDTA, ammonium cobalt sulfate (), ammonium cobalt chloride, cobalt acetate, cobalt hexacyano ( ) acid potassium, hexacyanocobalt ()
Examples include sodium acid, cobalt-EDTA, ammonium nickel sulfate, ammonium nickel chloride, nickel sulfate, potassium tetracyanonickelate, nickel-EDTA, and the like. These compounds are usually used alone or in combination of two or more.
A concentration of 0.005 to 0.1 mol/, preferably 0.01 to 0.05 mol/ is used. Also, hydrogen sulfide easily reacts with hydroxyanthraquinone sulfonic acid.
To make NaHS, carbonates of ammonium carbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, and lithium carbonate are used in combination. The amount used is usually 0.01 to 1.0 mol/,
Preferably it is used in an amount of 0.1 to 0.5 mol/. Therefore, the alkaline aqueous solution containing the above components has a pH of 7 to 10, preferably 8.5 to 10.
9.5, and if necessary, ammonia, sodium hydroxide, potassium hydroxide, lithium hydroxide, etc. can be used as a regulating agent. The aqueous solution is brought into contact with hydrogen sulfide-containing gas in an absorption tower such as a packed tower, tray tower, grid tower, or spray tower, so that hydrogen sulfide is absorbed into the aqueous solution, and the gas discharged from the absorption tower contains hydrogen sulfide. Contains virtually no hydrogen sulfide. In this case, the gas-liquid ratio (supply liquid amount/to-be-processed gas amount) is usually 5 to 100/m ³
and preferably 10 to 50/m ³ . The contact temperature is 10-70°C, preferably 20-50°C. The aqueous solution that has absorbed hydrogen sulfide in this way is extracted from the tower and sent to the regeneration tower, where it is brought into contact with a molecular oxygen-containing gas such as air to oxidize the HS ^- present in the aqueous solution, and At the same time as being recovered as sulfur or other sulfur compounds such as thiosulfates, rhodan salts, etc., the aqueous solution is regenerated and recycled to the absorption tower. Next, the method of the present invention will be explained in more detail by referring to Reference Examples and Examples. Note that parts and percentages below are by weight unless otherwise specified. Reference Example 1 750 parts of sodium anthraquinone-2,6-disulfonate (purity 95%), 310 parts of calcium oxide, and 6000 parts of water were placed in an iron autoclave and heated at a temperature of 160°C and a pressure of 6 kg/ ^cm2 for 12 hours with stirring. It was melted. The reaction solution was cooled to below 100°C and the solid content was separated. Sulfuric acid was added to the resulting solution to cause acid precipitation, and the precipitated crystals were separated and dried to obtain 400 parts of yellow crystals of sodium 2-hydroxyanthraquinone-6-sulfonate (anthraquinone-2,6-disulfonic acid). Sodium conversion rate 85
%, purity 91%, yield 65 mol%). Reference Example 2 750 parts of sodium anthraquinone-2,6-disulfonate (purity 95%), 310 parts of calcium oxide, and 6000 parts of water were placed in an iron autoclave, and the mixture was stirred at a temperature of 180°C and a pressure of 10 kg/ ^cm2 for 36 hours. It was melted. The reaction solution was cooled to below 100°C and the solid content was separated. Sulfuric acid was added to the resulting solution to precipitate it, and the precipitated crystals were separated and dried to give yellow crystals of 2,6-dihydroxyanthraquinone.
360 parts were obtained (purity 90%, yield 78 mol%). Reference example 3 Sodium anthraquinone-2,6-disulfonate (purity 95%) 750 parts, calcium oxide 310 parts,
310 parts of magnesium chloride and 6000 parts of water were placed in an iron autoclave at a temperature of 180°C and a pressure of 10 kg/kg.
Thaw for 12 hours with stirring at cm ² .
The reaction solution was cooled to below 100°C and the solid content was separated. Sulfuric acid was added to the obtained solution to precipitate the acid, and the precipitated crystals were separated and dried to obtain 350 parts of yellow crystals of 2,6-dihydroxyanthraquinone (purity 89).
%, yield 75 mol%). Reference Example 4 280 parts of sodium anthraquinone-2,6-disulfonate (purity 90%), 520 parts of 40% aqueous sodium hydroxide solution, and 31 parts of sodium nitrate were placed in an iron autoclave, and the temperature was 220°C and the pressure was 13 kg/kg.
Thaw for 6 hours with stirring at cm ² .
After the reaction solution was cooled to below 100°C, 900 parts of water was poured into it, and acid precipitation was performed with sulfuric acid. The precipitated crystals were dried separately to separate 2,6-dihydroxyanthraquinone and 1.
155 parts of orange crystals of a mixture with 2,6-trihydroxyanthraquinone were obtained (2,6-dihydroxyanthraquinone purity 39%, 1,2,6-trihydroxyanthraquinone purity 45%, yield 86 mol%). Reference Example 5 When the same method as Reference Example 4 was carried out except that the reaction time was changed to 36 hours, 1.
145 parts of 2,6-trihydroxyanthraquinone was obtained (purity 85%, yield 79 mol%). Reference Example 6 100 parts of sodium 2-hydroxyanthraquinone-6-sulfonate obtained in Reference Example 1 was added to 25% oleum in a glass round-bottomed flask.
The mixture was added to 400 parts while stirring while maintaining the temperature at 70°C. After the addition was completed, the temperature was raised to 120°C and a sulfonation reaction was carried out for 1 hour. After cooling, pour 270 parts of water containing 18 parts of sulfuric anhydride, separate the precipitated crystals, wash the resulting cake with an aqueous sodium sulfate solution, and if necessary, neutralize with an aqueous sodium hydroxide solution and separate. did. Then, dry 2-
135 parts of yellow crystals of sodium hydroxyanthraquinone-3,6-disulfonate were obtained (purity 75
%, yield 85 mol%). Reference Example 7 100 parts of 2,6-dihydroxyanthraquinone obtained in Reference Examples 2 and 3 were treated in the same manner as in Reference Example 6 to obtain yellow crystals of sodium 2,6-dihydroxyanthraquinone-3,7-disulfonate. 175 parts were obtained (purity 78%, yield 81 mol%). Reference Example 8 100 parts of the mixture of 2,6-dihydroxyanthraquinone and 1,2,6-trihydroxyanthraquinone obtained in Reference Example 4 was treated in the same manner as in Reference Example 6 to obtain 2,6-dihydroxyanthraquinone.
Sodium 3,7-disulfonate and 1,2,6-
165 parts of colored crystals of a mixture of trihydroxyanthraquinone and sodium 3,7-disulfonate were obtained (2,6-dihydroxyanthraquinone).
Sodium 3,7-disulfonate purity 36%, 1.
2,6-trihydroxyanthraquinone-3,7
- Sodium disulfonate purity 37%, yield 79 mol%). Reference Example 9 100 parts of 1,2,6-trihydroxyanthraquinone obtained in Reference Example 5 was treated in the same manner as in Reference Example 6 to obtain sodium 1,2,6-trihydroxyanthraquinone-3,7-disulfonate. And 170 parts of colored crystals were obtained (purity 72%, yield 80 mol%). Example 1 6.8 g/Nm ³ of hydrogen sulfide was added to the nitrogen gas from the bottom of an absorption tower made by filling a jacketed glass tube with an inner diameter of 5.5 cm and a length of 150 cm with glass bulbs of 0.6 cm in diameter to a height of 100 cm. The hydrogen sulfide-containing gas was introduced at a flow rate of 80/hr. On the other hand, 0.005 mol of sodium 2-hydroxyanthraquinone-6-sulfonate and 0.05 mol of ammonium metavanadate obtained in Reference Example 1 were extracted from the upper part of the absorption tower.
and sodium carbonate 0.06 mol/, sodium hydrogen carbonate 0.3 mol/and potassium tartrate
A 30° C. alkaline aqueous solution containing 0.02 mol/hr and adjusted by adding an aqueous sodium carbonate solution so as to maintain the pH at 8.8 at all times was sprayed at a flow rate of 2/hr and brought into contact with the hydrogen sulfide-containing gas.
The gas-liquid ratio at this time was 25/ ^M3 . The liquid is continuously extracted from the bottom of the absorption tower and the inner diameter is 4.
cm, and was sent to a regeneration tower made of a jacketed glass tube with a length of 120 cm, and air was blown into the bottom of the regeneration tower to precipitate sulfur. The residence time of the alkaline aqueous solution in the regeneration tower was 30 minutes. Hydrogen sulfide-containing gas was treated in this way for 24 hours,
Hydrogen sulfide in the hydrogen sulfide-containing gas could be removed with a desulfurization rate of 99.5% or higher. Examples 2 to 5 Instead of sodium 2-hydroxyanthraquinone-6-sulfonate obtained in Reference Example 1, sodium 2-hydroxyanthraquinone-3,6-disulfonate obtained in each of the above-mentioned Reference Examples (Reference Example 6) was used. ), sodium 2,6-dihydroxy-3,7-disulfonate (Reference Example 7), sodium 2,6-dihydroxyanthraquinone-3,7-disulfonate and 1,2,6-trihydroxyanthraquinone-3,7- Example 1 using a mixture with sodium disulfonate (Reference Example 8) and sodium 1,2,6-trihydroxyanthraquinone-3,7-disulfonate (Reference Example 10), respectively.
When hydrogen sulfide-containing gas was treated in the same manner as above, the desulfurization rate was as shown in Table 1.

[Table] M As described above, the method for desulfurizing hydrogen sulfide-containing gas according to the present invention can be applied almost immediately during the production of anthraquinone-2,7-disulfonic acid or its salt, which has been conventionally used as a desulfurization agent in the stretch food method. Anthraquinone-2,6-disulfonic acid or its salt, which was produced as a by-product in about the same amount and had almost no use, is induced into hydroxyanthraquinone-2,6-disulfonic acid having the general formula, and this is used alone or as anthraquinone-2,7-disulfonic acid. Since it is used as a desulfurization agent together with disulfonic acid or its salt, it not only provides sufficient desulfurization ability but also makes effective use of the by-product anthraquinone-2,6-disulfonic acid or its salt. This method is economically advantageous because it can supply the desulfurization agent used in the conventional stress hood method at a low cost.

Claims (1)

[Claims] 1 Hydrogen sulfide-containing gas is expressed by the general formula (In the formula, m and n are integers of 1 to 4, and M represents H, NH ₄ or an alkali metal.) An alkaline aqueous solution consisting of a hydroxyanthraquinone sulfonic acid, a variable valence metal compound, and a carbonate. 1. A method for desulfurizing a hydrogen sulfide-containing gas, which comprises bringing hydrogen sulfide into contact with the aqueous solution and absorbing the hydrogen sulfide into the aqueous solution. 2. The variable valence metal compound is a compound that is soluble in an alkaline aqueous solution of hydroxyanthraquinone sulfonic acid and has a general formula of at least one metal selected from the group consisting of iron, chromium, manganese, vanadium, copper, cobalt, and nickel. The method according to claim 1. 3. The method according to claim 1 or 2, wherein the alkaline aqueous solution is adjusted to have a pH of 7 to 10. 4. The method according to any one of claims 1 to 3, wherein the alkaline aqueous solution contains hydroxyanthraquinone sulfonic acid at a concentration of 0.001 to 0.05 mol/.