Method for removing SOx from gas with compound alcohol-amine solution

Abstract

A method for removing SO.sub.x from a gas by using a compound alcohol-amine solution is provided. The compound alcohol-amine solution is made by mixing ethylene glycol and/or polyethylene glycol with hydroxyl and/or carboxyl organic compound having basic group containing nitrogen. The compound alcohol-amine solution is contacted with the gas containing SO.sub.x to absorb the SO.sub.x in the gas, wherein x=2 and/or 3. The compound alcohol-amine solution with absorbed SO.sub.x is regenerated by one or more of heating method, vacuum method, gas stripping method, ultrasonic method, microwave method, and radiation method to release by-products of sulfur dioxide and sulfur trioxide, and the regenerated compound alcohol-amine solution is recycled for use. This method can be used for removing SO.sub.x from flue gas, burning gas, coke-oven gas, synthesis waste gas from dyestuff plants, sewage gas from chemical fiber plants, and other industrial raw material gases or waste gases containing SO.sub.x.

Claims

1. A method for removing SO.sub.x from a gas, which comprises: making a compound alcohol-amine solution by mixing ethylene glycol and/or polyethylene glycol with hydroxyl/carboxyl organic compound having basic group containing nitrogen, bringing the compound alcohol-amine solution into contact with the gas containing SO.sub.x to absorb the SO.sub.x in the gas, wherein x=2 and/or 3; the hydroxyl/carboxyl organic compound having basic group containing nitrogen is one or more of hydroxyl organic compound having basic group containing nitrogen, carboxylic acid organic compound having basic group containing nitrogen, and carboxylate organic compound having basic group containing nitrogen, wherein the hydroxyl organic compound having basic group containing nitrogen is alcohol amine compound; the carboxylic acid organic compound having basic group containing nitrogen is organic compound comprising both carboxylic acid group and amine group in a molecule; and the carboxylate organic compound having basic group containing nitrogen is carboxylate organic compound comprising both carboxylic acid group and amine group in a molecule.

2. The method for removing SO.sub.x from a gas according to claim 1, characterized in that, the hydroxyl organic compound having basic group containing nitrogen is selected from one or more of monomethanolamine, dimethanolamine, trimethanolamine, monoethanolamine, diethanolamine, triethanolamine, N,N-dimethyl ethanolamine, N,N-diethyl ethanolamine, N,N-diisopropyl ethanolamine, N-methyl diethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, monobutanolamine, dibutanolamine, tributanolamine, N-hydroxyethylethylenediamine, N,N-dihydroxyethylethylenediamine, N,N-dihydroxyethyl aniline, N-ethyl-N-hydroxyethyl aniline, N-methyl-N-hydroxyethyl aniline, o-aminophenol, m-aminophenol, p-aminophenol, 2,4,6-tri(dimethylaminomethyl)phenol, 3-diethylaminophenol, 2-amino-5-nitrophenol, aminothiaoximoacid, N-methylpyrrolidinyl alcohol, 2,4-diamino-6-hydroxy pyrimidine, cyanuric acid, 2-(2-hydroxy-5-methylphenyl)benzotriazole, Gamma acid, J acid, phenyl J acid, Chicago acid and its salts, H acid and its salts, di-J acid, scarlet acid and its salts.

3. The method for removing SO.sub.x from a gas according to claim 1, characterized in that, the carboxylic acid organic compound having basic group containing nitrogen is selected from one or more amino acids, EDTA, nitrilotriacetic acid, cyanoacetic acid, hippuric acid, o-aminobenzoic acid, o-aminophenylacetic acid, o-aminophenylpropionic acid, o-aminophenylbutyric acid, o-aminophenylpentoic acid, o-aminophenylhexylic acid, m-aminobenzoic acid, m-aminophenylacetic acid, m-aminophenylpropionic acid, m-aminophenylbutyric acid, m-aminophenylpentoic acid, m-aminophenylhexylic acid, p-aminobenzoic acid, p-aminophenylacetic acid, p-aminophenylpropionic acid, p-aminophenylbutyric acid, p-aminophenylpentoic acid, p-aminophenylhexylic acid, isonicotinic acid, and 2,3-pyrazine dicarboxylic acid.

4. The method for removing SO.sub.x from a gas according to claim 1, characterized in that, the carboxylate organic compound having basic group containing nitrogen is selected from one or more amino acid salts, EDTA salts, nitrilotriacetic acid salts, cyanoacetic acid salts, hippuric acid salts, o-aminobenzoic acid salts, m-aminobenzoic acid salts, p-aminobenzoic acid salts, o-aminophenylacetic acid salts, m-aminophenylacetic acid salts, p-aminophenylacetic acid salts, o-aminophenylpropionic acid salts, m-aminophenylpropionic acid salts, p-aminophenylpropionic acid salts, o-aminophenylbutyric acid salts, m-aminophenylbutyric acid salts, p-aminophenylbutyric acid salts, o-aminophenylpentoic acid salts, m-aminophenylpentoic acid salts, p-aminophenylpentoic acid salts, o-aminophenylhexylic acid salts, m-aminophenylhexylic acid salts, p-aminophenylhexylic acid salts, isonicotinic acid salts, and 2,3-pyrazine dicarboxylic acid salts.

5. The method for removing SO.sub.x from a gas according to claim 1, characterized in that, the mass percent content of the ethylene glycol and/or polyethylene glycol in the compound alcohol-amine solution is more than or equal to 50%, the mass percent content of the hydroxyl/carboxyl organic compound having basic group containing nitrogen is in the range of 0.1% to 30%, and the mass percent content of water is less than 20%.

6. The method for removing SO.sub.x from a gas according to claim 1, characterized in that, the compound alcohol-amine solution contains a certain amount of additives being organic amines, amides, sulfones, sulfoxides, organic acids, organic acid salts, and metallorganic compounds; the additives can be one or more of these substances; and the additives are present in the compound alcohol-amine solution in a mass percent content of less than 10%.

7. The method for removing SO.sub.x from a gas according to claim 1, characterized in that, the compound alcohol-amine solution absorbs the SO.sub.x in the gas under a normal or increased pressure at an absorption temperature of ?20 to 80? C.

8. The method for removing SO.sub.x from a gas according to claim 1, characterized in that, the compound alcohol-amine solution with absorbed SO.sub.x is regenerated by one or more of heating method, vacuum method, gas stripping method, ultrasonic method, microwave method, and radiation method at a regeneration temperature of 0 to 300? C. to release sulfur dioxide and/or sulfur trioxide, and the regenerated compound alcohol-amine solution is recycled for use.

9. The method for removing SO.sub.x from a gas according to claim 8, further comprising: removing water from the compound alcohol-amine solution when a mass percent content of water in said solution is more than 20%, and re-using the compound alcohol-amine solution into contact with the gas containing SO.sub.x to absorb the SO.sub.x in the gas.

10. The method for removing SO.sub.x from a gas according to claim 1, characterized in that, the method is utilized to remove SO.sub.x from flue gas, waste gas containing SO.sub.x and/or industrial raw material gas.

11. The method for removing SO.sub.x from a gas according to claim 9, wherein: the compound alcohol-amine solution contains at least one additives selected from the group consisting of organic amines, amides, sulfones, sulfoxides, organic acids, organic acid salts, and metallorganic compounds; and the at least one additives are present in the compound alcohol-amine solution in a mass percent content of less than 10%.

12. The method for removing SO.sub.x from a gas according to claim 11, characterized in that, the hydroxyl organic compound having basic group containing nitrogen is selected from one or more of monomethanolamine, dimethanolamine, trimethanolamine, monoethanolamine, diethanolamine, triethanolamine, N,N-dimethyl ethanolamine, N,N-diethyl ethanolamine, N,N-diisopropyl ethanolamine, N-methyl diethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, monobutanolamine, dibutanolamine, tributanolamine, N-hydroxyethylethylenediamine, N,N-dihydroxyethylethylenediamine, N,N-dihydroxyethyl aniline, N-ethyl-N-hydroxyethyl aniline, N-methyl-N-hydroxyethyl aniline, o-aminophenol, m-aminophenol, p-aminophenol, 2,4,6-tri(dimethylaminomethyl)phenol, 3-diethylaminophenol, 2-amino-5-nitrophenol, aminothiaoximoacid, N-methylpyrrolidinyl alcohol, 2,4-diamino-6-hydroxy pyrimidine, cyanuric acid, 2-(2-hydroxy-5-methylphenyl)benzotriazole, Gamma acid, J acid, phenyl J acid, Chicago acid and its salts, H acid and its salts, di-J acid, scarlet acid and its salts.

13. The method for removing SO.sub.x from a gas according to claim 11, characterized in that, the carboxylic acid organic compound having basic group containing nitrogen is selected from one or more amino acids, EDTA, nitrilotriacetic acid, cyanoacetic acid, hippuric acid, o-aminobenzoic acid, o-aminophenylacetic acid, o-aminophenylpropionic acid, o-aminophenylbutyric acid, o-aminophenylpentoic acid, o-aminophenylhexylic acid, m-aminobenzoic acid, m-aminophenylacetic acid, m-aminophenylpropionic acid, m-aminophenylbutyric acid, m-aminophenylpentoic acid, m-aminophenylhexylic acid, p-aminobenzoic acid, p-aminophenylacetic acid, p-aminophenylpropionic acid, p-aminophenylbutyric acid, p-aminophenylpentoic acid, p-aminophenylhexylic acid, isonicotinic acid, and 2,3-pyrazine dicarboxylic acid.

14. The method for removing SO.sub.x from a gas according to claim 11, characterized in that, the carboxylate organic compound having basic group containing nitrogen is selected from one or more amino acid salts, EDTA salts, nitrilotriacetic acid salts, cyanoacetic acid salts, hippuric acid salts, o-aminobenzoic acid salts, m-aminobenzoic acid salts, p-aminobenzoic acid salts, o-aminophenylacetic acid salts, m-aminophenylacetic acid salts, p-aminophenylacetic acid salts, o-aminophenylpropionic acid salts, m-aminophenylpropionic acid salts, p-aminophenylpropionic acid salts, o-aminophenylbutyric acid salts, m-aminophenylbutyric acid salts, p-aminophenylbutyric acid salts, o-aminophenylpentoic acid salts, m-aminophenylpentoic acid salts, p-aminophenylpentoic acid salts, o-aminophenylhexylic acid salts, m-aminophenylhexylic acid salts, p-aminophenylhexylic acid salts, isonicotinic acid salts, and 2,3-pyrazine dicarboxylic acid salts.

15. The method for removing SO.sub.x from a gas according to claim 11, characterized in that, the mass percent content of the ethylene glycol and/or polyethylene glycol in the compound alcohol-amine solution is more than or equal to 50%, the mass percent content of the hydroxyl/carboxyl organic compound having basic group containing nitrogen is in the range of 0.1% to 30%, and the mass percent content of water is less than 20%.

16. The method for removing SO.sub.x from a gas according to claim 11, characterized in that, the compound alcohol-amine solution absorbs the SO.sub.x in the gas under a normal or increased pressure at an absorption temperature of ?20 to 80? C.

17. The method for removing SO.sub.x from a gas according to claim 11, characterized in that, the method is utilized to remove SO.sub.x from flue gas, waste gas containing SO.sub.x and/or industrial raw material gas.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of desulfurization and absorption process.

(2) FIG. 2 is a schematic diagram of desulfurization solution regeneration by heating method.

(3) FIG. 3 is a schematic diagram of desulfurization solution regeneration by vacuum method.

(4) FIG. 4 is a schematic diagram of desulfurization solution regeneration by gas stripping method.

(5) FIG. 5 is a schematic diagram of desulfurization solution regeneration by ultrasonic method, and/or microwave method, and/or radiation method.

(6) FIG. 6 is a schematic diagram of structure of a small-sized desulfurization and absorption device.

(7) FIG. 7 is a schematic diagram of structure of a small-sized heating and gas stripping-regeneration device.

DETAILED DESCRIPTION

(8) The desulfurization method by compound alcohol-amine solution according to the invention is described below with reference to some specific embodiments. The embodiments described hereinafter are only for better illustrating the present invention rather than limiting the claims of the present invention.

(9) The first process is a desulfurization and absorption process as shown in FIG. 1. The gas 2 containing SO.sub.x is fed from the bottom of the desulfurization tower 1 and contacted with the desulfurization lean liquor 4 counter-currently. The SO.sub.x in the gas 2 containing SO.sub.x is absorbed by the lean liquor 4. The gas 2 containing SO.sub.x is converted into purified gas 3 which is discharged out from the top of the desulfurization tower 1. The desulfurization lean liquor 4 with absorbed SO.sub.x is converted into desulfurization rich liquor 5 at the bottom of the desulfurization tower 1. The desulfurization rich liquor 5 is discharged out from the bottom of the desulfurization tower 1 and transferred to the regenerator to be regenerated by one or more of heating method, vacuum method, gas stripping method, ultrasonic method, microwave method, and radiation method.

(10) The second process is the regeneration process of desulfurization solution. The regeneration methods for it include heating method, vacuum method, gas stripping method, ultrasonic method, microwave method, and radiation method.

(11) The regeneration method by heating is shown in FIG. 2. The desulfurization rich liquor 5 is transferred to the heating-regenerator 6 and is heated to release gaseous sulfur dioxide and/or sulfur trioxide 7. The gaseous sulfur dioxide and/or sulfur trioxide 7 are processed into by-products of liquid sulfur dioxide and/or sulfur trioxide of high purity. Meanwhile, sulfur foams and/or dusts 8 may be produced or accumulated, and are separated from the desulfurization solution. The separated sulfur foams and/or dusts 8 can be further processed into sulfur by-products, and there are also some ash residues discharged. The desulfurization rich liquor 5 is regenerated by heating-regenerator 6 and is then converted into the desulfurization lean liquor 4. The desulfurization lean liquor 4 can be transferred directly to the desulfurization and absorption process for recycle use. Alternatively, it can be transferred to the vacuum-regenerator and/or gas stripping-regenerator, and/or ultrasonic-regenerator, and/or microwave-regenerator, and/or radiation-regenerator to be further regenerated.

(12) The regeneration method by vacuum is shown in FIG. 3. The desulfurization rich liquor 5 is transferred to the vacuum-regenerator 9, vacuum is created with the aid of vacuumizer 10 to release gaseous sulfur dioxide and/or sulfur trioxide 7. The gaseous sulfur dioxide and/or sulfur trioxide 7 are processed into by-products of liquid sulfur dioxide and/or sulfur trioxide of high purity. Meanwhile, sulfur foams and/or dusts 8 may be produced or accumulated, and are separated from the desulfurization solution. The separated sulfur foams and/or dusts 8 can be further processed into sulfur by-products, and there are also some ash residues discharged. The desulfurization rich liquor 5 is regenerated by vacuum-regenerator 9 and is then converted into the desulfurization lean liquor 4. The desulfurization lean liquor 4 can be transferred directly to the desulfurization and absorption process for recycle use. Alternatively, it can be transferred to the heating-regenerator and/or gas stripping-regenerator, and/or ultrasonic-regenerator, and/or microwave-regenerator, and/or radiation-regenerator to be further regenerated.

(13) The regeneration method by gas stripping is shown in FIG. 4. The desulfurization rich liquor 5 is transferred to the gas stripping-regenerator 11, and contacted counter-currently with the inert gas 12 (including nitrogen, argon and water vapour, etc.) from the bottom of the gas stripping-regenerator 11. The sulfur dioxide and/or sulfur trioxide in the desulfurization rich liquor 5 are released into the inert gas and a mixed gas 13 of sulfur dioxide and/or sulfur trioxide with high concentration is formed and discharged from the top of the gas stripping-regenerator 11. The discharged sulfur dioxide and/or sulfur trioxide in the inert gas are processed into by-products of liquid sulfur dioxide and/or sulfur trioxide of high purity. The desulfurization rich liquor 5 is regenerated by the gas striping-regenerator 11 and is then converted into the desulfurization lean liquor 4. The desulfurization lean liquor 4 can be transferred directly to the desulfurization and absorption process for recycle use. Alternatively, it can be transferred to the heating-regenerator and/or vacuum-regenerator, and/or ultrasonic-regenerator, and/or microwave-regenerator, and/or radiation-regenerator to be further regenerated.

(14) The regeneration by ultrasonic method, and/or microwave method, and/or radiation method is shown in FIG. 5. The desulfurization rich liquor 5 is transferred to the ultrasonic-, and/or microwave-, and/or radiation-regenerator 14 and regenerated under the conditions of ultrasonic, and/or microwave, and/or radiation to release gaseous sulfur dioxide and/or sulfur trioxide 7. The gaseous sulfur dioxide and/or sulfur trioxide 7 are processed into by-products of liquid sulfur dioxide and/or sulfur trioxide of high purity. Meanwhile, sulfur foams and/or dusts 8 may be produced or accumulated, and are separated from the desulfurization solution. The separated sulfur foams and/or dusts 8 can be further processed into sulfur by-products, and there are also some ash residues discharged. The desulfurization rich liquor 5 is regenerated by ultrasonic-, and/or microwave-, and/or radiation-regenerator 14 and is then converted into the desulfurization lean liquor 4. The desulfurization lean liquor 4 can be transferred directly to the desulfurization and absorption process for recycle use. Alternatively, it can be transferred to the heating-regenerator, and/or vacuum-regenerator, and/or gas stripping-regenerator to be further regenerated.

(15) When the regenerated compound alcohol-amine solution has relatively high water content and the desulfurization effects are influenced, it is needed to remove water from the compound alcohol-amine solution. The methods for removing water include distillation method by heating, absorption method with water absorbent or combination thereof. The compound alcohol-amine solution with water removed is recycled for use. The commonly used water absorbents include CaO, anhydrous CaSO.sub.4, silica gel and water absorbent resins.

(16) According to the specific concepts of the above embodiments, a small-sized absorption device shown in FIG. 6 and a small-sized heating and gas stripping-regeneration device shown in FIG. 7 were designed and mounted respectively.

(17) As shown in FIG. 6, in the small-sized absorption device, 15 represented an absorption bottle (or a regeneration bottle if regeneration was carried out), 16 represented the compound alcohol-amine solution, 17 represented the gas containing sulfur dioxide, and 18 represented a vented gas.

(18) As shown in FIG. 7, in the small-sized heating and gas stripping-regeneration device, 15 represented a regeneration bottle (or an absorption bottle if absorption was carried out), 16 represented the compound alcohol-amine solution with absorbed sulfur dioxide, 19 represented a gas for gas stripping (N.sub.2 in this test), 20 represented the stripping gas with sulfur dioxide contained, 21 represented a silicone oil for oil bath, and 22 represented a thermostatic heating pot.

(19) In the experiment, as shown in FIG. 6, about 100 ml fresh compound alcohol-amine solution 16 was charged into the absorption bottle 15. A certain amount (L, litre) of gas 17 containing sulfur dioxide was blown into the absorption bottle 15 containing the compound alcohol-amine solution 16 at room temperature and passed through the compound alcohol-amine solution 16. The sulfur dioxide in the gas was absorbed by the compound alcohol-amine solution 16. The gas with sulfur dioxide removed was referred to as the vented gas 18. The vented gas 18 was discharged outside. At the same time, the content of sulfur dioxide (C*.sub.SO2, g/L) in the compound alcohol-amine solution 16 was measured using iodimetry. Then, the absorption bottle containing the compound alcohol-amine solution with absorbed sulfur dioxide was placed into the thermostatic heating pot in the oil bath. At this time, the absorption bottle 15 served as the regeneration bottle 15. The content of sulfur dioxide in the compound alcohol-amine solution 16 had already been measured and it could be used as the compound alcohol-amine solution 16 with absorbed sulfur dioxide to be regenerated. As shown in FIG. 7, the temperature in the thermostatic heating pot 22 was adjusted to a desired constant temperature by heating the silicone oil 21 for oil bath. When the temperature of the system was kept at the desired temperature (t, ? C.), the gas 19 for gas stripping (N.sub.2 in this test) was blown into the regeneration bottle 15. The gas 19 for gas stripping (N.sub.2 in this test) was sufficiently contacted with the compound alcohol-amine solution 16 containing sulfur dioxide. At this time, the sulfur dioxide contained in the compound alcohol-amine solution 16 was transferred into the gas 19 for gas stripping (N.sub.2 in this test). At this time, the gas 19 for gas stripping (N.sub.2 in this test) containing sulfur dioxide was transformed into the stripping gas 20 with contained sulfur dioxide, vented and discharged outside. After being regenerated for a period of time (T, min) by heating and gas stripping, the regeneration bottle 15 was taken out and cooled to normal temperature with water. The content of sulfur dioxide (C.sub.SO2, g/L) in the regenerated compound alcohol-amine solution 16 was measured using iodimetry. The absorption and regeneration of the regenerated compound alcohol-amine solution 16 were repeated many times in accordance with the above steps. The changes appeared in the compound alcohol-amine solution were observed. According to the above test, the experiments for the absorption and desorption of SO.sub.2 contained in the gas were repeated many times with a system of EG +5% triethanolamine, a system of PEG(400)+5% triethanolamine, a system of EG +10% EDTA, a system of EG+2% EDTA disodium salt, a system of EG +5% EDTA disodium salt, a system of EG +10% EDTA disodium salt, and a system of EG+2% EDTA disodium salt+1% triethanolamine. The experiment data were respectively listed in table 1, table 2, table 3, table 4, table 5, table 6 and table 7.

(20) TABLE-US-00001 TABLE 1 the absorption and desorption of SO.sub.2 with EG + 5% triethanolamine (150 mL) Content of sulfur dioxide in Content of the Volume of sulfur dioxide compound gas to be in the alcohol- Appearance absorbed compound amine of the Numbers (the content alcohol-amine solution compound of of SO.sub.2 in the solution after after alcohol- absorption gas is about absorption regeneration Regeneration Regeneration amine and 1%) L C*.sub.SO2 C.sub.SO2 temperature t time T solution after regeneration (liter) (g/L) (g/L) (? C.) (min) regeneration 1.sup.st 36 6.9924 3.1993 150 30 The color of 2.sup.nd 6 4.6176 2.9685 150 30 the solution 3.sup.rd 6.4 4.4527 3.0344 150 30 gradually 4.sup.th 10 5.6071 2.9025 150 30 turned into 5.sup.th 6 5.5411 2.0120 150 30 brownish red 6.sup.th 6 3.8260 2.2758 150 30 from 7.sup.th 6 4.4527 2.2428 140 30 colorless. 8.sup.th 6 2.6386 1.9790 140 30 9.sup.th 6 2.0779 1.9130 140 30 10.sup.th 6 2.5727 1.9790 140 30 11.sup.th 6 2.6716 1.9460 140 30 12.sup.th 6 2.3418 1.7481 140 30

(21) TABLE-US-00002 TABLE 2 the absorption and desorption of SO.sub.2 with PEG(400) + 5% triethanolamine (150 mL) Content of Content of sulfur Volume of sulfur dioxide dioxide in the gas to be in the compound Appearance absorbed compound alcohol- of the Numbers (the content alcohol-amine amine compound of of SO.sub.2 in solution after solution after alcohol- absorption the gas is absorption regeneration Regeneration Regeneration amine and about 1500 ppm) L C*.sub.SO2 C.sub.SO2 temperature t time T solution after regeneration (liter) (g/L) (g/L) (? C.) (min) regeneration 1.sup.st 55 1.6194 0.1747 130 30 The color of 2.sup.nd 12 0.5398 0.1270 130 30 the solution 3.sup.rd 12 0.5557 0.1588 130 30 gradually 4.sup.th 12 0.5081 0.1429 130 30 turned into 5.sup.th 12 0.5239 0.1429 130 30 brownish red 6.sup.th 12 0.4446 0.1040 130 30 from 7.sup.th 12 0.5199 0.2773 130 30 colorless. 8.sup.th 13 0.6066 0.4333 130 30 9.sup.th 13 0.8319 0.4853 130 30 10.sup.th 12 0.7361 0.3848 130 30 11.sup.th 12 0.7361 0.1338 130 30 12.sup.th 12 0.5186 0.1004 130 30

(22) TABLE-US-00003 TABLE 3 the absorption and desorption of SO.sub.2 with EG + 10% EDTA (150 mL) Content of sulfur Content of Volume of dioxide in the sulfur dioxide gas to be compound in the Appearance absorbed alcohol- compound of the Numbers (the content amine alcohol-amine compound of of SO.sub.2 in solution after solution after alcohol- absorption the gas is absorption regeneration Regeneration Regeneration amine and about 1%) L C*.sub.SO2 C.sub.SO2 temperature t time T solution after regeneration (liter) (g/L) (g/L) (? C.) (min) regeneration 1.sup.st 4 0.7421 0.0825 130 30 The color of 2.sup.nd 4 0.8410 0.0825 130 30 the solution 3.sup.rd 4 0.7586 0.0330 130 30 gradually 4.sup.th 4 0.8410 0.0330 130 30 turned into 5.sup.th 4 0.8246 0.0330 130 30 faint yellow 6.sup.th 4 0.7916 0.0495 130 30 from 7.sup.th 4 0.8576 0.0330 130 30 colorless.

(23) TABLE-US-00004 TABLE 4 the absorption and desorption of SO.sub.2 with EG + 2% EDTA disodium salt (150 mL) Content of sulfur Content of Volume of dioxide in the sulfur dioxide gas to be compound in the Appearance absorbed alcohol- compound of the Numbers (the content amine alcohol-amine compound of of SO.sub.2 in the solution after solution after alcohol- absorption gas is about absorption regeneration Regeneration Regeneration amine and 1%) L C*.sub.SO2 C.sub.SO2 temperature t time T solution after regeneration (liter) (g/L) (g/L) (? C.) (min) regeneration 1.sup.st 3 0.8246 0.8246 135 30 The color of 2.sup.nd 20 7.0913 0.7615 135 30 the solution 4.sup.th 10 6.1678 0.6597 135 30 gradually 3.sup.rd 10 6.2667 0.6597 135 30 turned into 5.sup.th 10 3.3643 0.4947 135 30 faint yellow 6.sup.th 10 4.9474 1.6491 135 15 from colorless.

(24) TABLE-US-00005 TABLE 5 the absorption and desorption of SO.sub.2 with EG + 5% EDTA disodium salt (150 mL) Content of sulfur Content of dioxide in sulfur Volume of the dioxide in gas to be compound the Appearance absorbed alcohol- compound of the (the amine alcohol- compound Numbers content of solution amine alcohol- of SO.sub.2 in the after solution after amine absorption gas is about absorption regeneration Regeneration Regeneration solution and 1%) L C*.sub.SO2 C.sub.SO2 temperature t time T after regeneration (liter) (g/L) (g/L) (? C.) (min) regeneration 1.sup.st 2.8 0.5937 0.5937 / 0 The color of 2.sup.nd 2.04 0.9895 0.5937 135 30 the solution 3.sup.rd 2.01 1.0884 0.4947 135 30 gradually 4.sup.th 1.3 0.8576 0.1649 135 30 turned into 5.sup.th 10 2.8035 0.5937 135 30 faint yellow 6.sup.th 10 3.5292 0.4288 135 30 from 7.sup.th 10 3.6611 0.3958 135 30 colorless 8.sup.th 10 3.5951 0.3958 135 30 and 9.sup.th 10 3.7930 0.3298 135 30 maintained 10.sup.th 10 3.5951 0.6597 135 30 to be faint 11.sup.th 10 3.8920 0.3958 135 30 yellow. 12.sup.th 10 3.8260 0.2968 135 30 13.sup.th 10 3.9579 0.1979 135 30 14.sup.th 10 3.7930 0.2968 135 30 15.sup.th 10 2.9685 0.8246 135 30 16.sup.th 10 3.4632 0.7586 135 30 17.sup.th 10 3.9579 0.6597 135 30 18.sup.th 10 4.4857 1.0225 135 30 19.sup.th 10 4.5187 0.2097 135 60 20.sup.th 10 3.3062 0.2903 135 30 21.sup.st 10 2.8224 0.7258 135 30

(25) TABLE-US-00006 TABLE 6 the absorption and desorption of SO.sub.2 with EG + 10% EDTA disodium salt (150 mL) Content of sulfur Content of Volume of dioxide in the sulfur dioxide gas to be compound in the Appearance absorbed alcohol- compound of the (the content amine alcohol-amine compound Numbers of of SO.sub.2 in the solution after solution after alcohol- absorption gas is about absorption regeneration Regeneration Regeneration amine and 1%) L C*.sub.SO2 C.sub.SO2 temperature t time T solution after regeneration (liter) (g/L) (g/L) (? C.) (min) regeneration 1.sup.st 10 2.7046 0.3298 135 30 The color of 2.sup.nd 10 3.3972 0.6597 135 30 the solution 3.sup.rd 10 3.5621 0.4947 135 30 gradually 4.sup.th 10 3.9250 0.4618 135 30 turned into 5.sup.th 10 3.7930 0.6597 135 30 brownish red 6.sup.th 10 4.7825 0.6597 135 30 from 7.sup.th 10 4.2878 0.4947 135 30 colorless. 8.sup.th 10 4.4527 0.4288 135 30 9.sup.th 10 4.6836 0.4947 135 30 10.sup.th 10 4.4857 0.7741 135 30 11.sup.th 10 3.8062 0.6451 135 30 12.sup.th 10 4.1126 1.2096 135 30

(26) TABLE-US-00007 TABLE 7 the absorption and desorption of SO.sub.2 with EG + 2% EDTA disodium salt + 1% triethanolamine (150 mL) Content of sulfur dioxide in Content of Volume of the sulfur dioxide gas to be compound in the Appearance absorbed alcohol- compound of the (the content amine alcohol-amine compound Numbers of of SO.sub.2 in the solution after solution after alcohol- absorption gas is about absorption regeneration Regeneration Regeneration amine and 1%) L C*.sub.SO2 C.sub.SO2 temperature t time T solution after regeneration (liter) (g/L) (g/L) (? C.) (min) regeneration 1.sup.st 10 4.1888 3.2983 135 30 The color of 2.sup.nd 10 6.1678 3.9579 135 30 the solution 3.sup.rd 10 6.1018 5.1123 135 30 gradually 4.sup.th 10 6.7615 4.4527 135 30 turned into 5.sup.th 10 6.5966 4.4527 135 30 brownish red 6.sup.th 10 7.9159 3.8590 135 30 from 7.sup.th 10 6.7615 4.3550 135 30 colorless. 8.sup.th 14 8.9054 3.7930 135 30 9.sup.th 10 7.4211 5.3123 135 30 10.sup.th 10 10.8843 3.1334 135 30 11.sup.th 10 8.0808 3.6281 135 30 12.sup.th 10 6.2093 3.7271 135 30 13.sup.th 10 7.7414 2.9030 135 135

(27) From the above experimental data, it can be seen that these compound alcohol-amine solutions have good effects on absorption and regeneration for SO.sub.2. This indicates that these systems are good desulfurization solvents for flue gases.