Method for removing SOx from gas using polyol composite solution

Abstract

A method for removing SO.sub.x from a gas by using a polyol composite solution is provided. The polyol composite solution is made by mixing a polyol with an organic acid and/or organic acid salt, the polyol composite solution is brought into contact with the gas containing SO.sub.x to absorb the SO.sub.x in the gas, wherein x=2 and/or 3, and the polyol refers to an organic compound other than ethylene glycol and polyethylene glycol, which contains simultaneously two or more than two hydroxyl groups in a same organic molecule.

Claims

1. A method for removing SO.sub.x from a gas, comprising: bringing a polyol composite solution comprising a mixture of a polyol and an organic acid and/or an organic acid salt into contact with the gas to absorb SO.sub.x in the gas, wherein x=2 and/or 3, wherein the polyol is propanediol, butanediol, butanetriol, isobutanediol, isobutanetriol, pentanediol, pentanetriol, pentanetetraol, isopentanediol, isopentanetriol, isopentanetetraol, polypropanol, polybutanol, or a mixture thereof.

2. The method for removing SO.sub.x from a gas according to claim 1, wherein the polyol is selected from the group consisting of butanetriol, isobutanetriol, pentanetriol, pentanetetraol, isopentanetriol, isopentanetetraol, and mixtures thereof.

3. The method for removing SO.sub.x from a gas according to claim 1, wherein the polyol composite solution further contains a part comprising ethylene glycol, or polyethylene glycol, or a mixture of ethylene glycol and polyethylene glycol, wherein a mass content of said part in the polyol composite solution is less than 30%.

4. The method for removing SO.sub.x from a gas according to claim 1, wherein the organic acid includes an organic monoacid and an organic polyacid; the organic acid salt includes an organic monoacid salt and an organic polyacid salt.

5. The method for removing SO.sub.x from a gas according to claim 4, wherein the organic monoacid is selected from the group consisting of formic acid, acetic acid, butyric acid, amino acids, and mixtures thereof; the organic polyacid is selected from the group consisting of ethanedioic acid, propanedioic acid, butanedioic acid, aminoethanedioic acid, nitrilotriacetic acid, EDTA, tannin acid, polygallic acid, citric acid, and mixtures thereof; the organic monoacid salt is selected from the group consisting of carboxylic acid salts formed by carboxyl group of the organic monoacid bonding to ammonium ions, sodium ions, potassium ions, magnesium ions, calcium ions, transition metal ions, and mixtures thereof; the organic polyacid salt is selected from the group consisting of carboxylic acid salts formed by at least one carboxylic acid group of the organic polyacid bonding to ammonium ions, sodium ions, potassium ions, magnesium ions, calcium ions, transition metal ions, and mixtures thereof.

6. The method for removing SO.sub.x from a gas according to claim 1, wherein the total mass content of the polyol, the organic acid and/or organic acid salt in the polyol composite solution is more than or equal to 50%, the mass content of water is less than 50%, and the mass content of the organic acid and/or organic acid salt in the polyol composite solution is less than 30%.

7. The method for removing SO.sub.x from a gas according to claim 1, wherein the polyol composite solution contains a certain amount of additives, the additives being one or more of organic amines, alkylol amines, amides, sulfones, sulfoxides, and metallorganic compounds, and the mass content of the additives in the polyol composite solution is less than 10%.

8. The method for removing SO.sub.x from a gas according to claim 1, wherein the polyol composite solution absorbs the SO.sub.x in the gas under a normal or elevated pressure at an absorption temperature of ?20 to 80? C.

9. The method for removing SO.sub.x from a gas according to claim 1, wherein the polyol composite solution with absorbed SO.sub.x is regenerated by a heating method, a vacuum method, a gas stripping method, an ultrasonication method, a microwave method, or a radiation method, the regeneration is carried out at a temperature of 0 to 300? C., sulfur dioxide and/or sulfur trioxide are released in the regeneration; and the regenerated polyol composite solution is recycled for use.

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

11. The method for removing SO.sub.x from a gas according to claim 1, wherein the polyol is selected from the group consisting of propanediol, butanediol, isobutanediol, pentanediol, isopentanediol, polypropanol, polybutanol, and mixtures thereof.

12. The method for removing SO.sub.x from a gas according to claim 1, wherein the polyol is polypropanol, polybutanol, or a mixture thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

(6) FIG. 6 is a schematic diagram of structure of a small-sized desulfurization-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 polyol composite solution according to the present invention will be 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-absorption process, and its embodiment is 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 desulfurization solution regeneration process to be regenerated by one or more of a heating method, a vacuum method, a gas stripping method, an ultrasonication method, a microwave method, and a radiation method.

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

(11) The embodiment of 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 may be transformed into by-products of liquid sulfur dioxide and/or sulfur trioxide of high purity by a certain processing means. Meanwhile, sulfur foams and/or dusts 8 may be produced or accumulated, and are separated from the main part of 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-absorption process for recycle use. Alternatively, it can be transferred to the vacuum-regenerator and/or gas stripping-regenerator, and/or ultrasonication-regenerator, and/or microwave-regenerator, and/or radiation-regenerator to be further regenerated.

(12) The embodiment of 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 vacuum machine 10 to release gaseous sulfur dioxide and/or sulfur trioxide 7. The gaseous sulfur dioxide and/or sulfur trioxide 7 may be transformed into by-products of liquid sulfur dioxide and/or sulfur trioxide of high purity by a certain processing means. Meanwhile, sulfur foams and/or dusts 8 may be produced or accumulated, and are separated from the main part of 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-absorption process for recycle use. Alternatively, it can be transferred to the heating-regenerator and/or gas stripping-regenerator, and/or ultrasonication-regenerator, and/or microwave-regenerator, and/or radiation-regenerator to be further regenerated. The embodiment of 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, carbon dioxide, 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 may be transformed into by-products of liquid sulfur dioxide and/or sulfur trioxide of high purity by a certain processing means. 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-absorption process for recycle use. Alternatively, it can be transferred to the heating-regenerator and/or vacuum-regenerator, and/or ultrasonication-regenerator, and/or microwave-regenerator, and/or radiation-regenerator to be further regenerated.

(13) The embodiment of regeneration by ultrasonication method, and/or microwave method, and/or radiation method is shown in FIG. 5. The desulfurization rich liquor 5 is transferred to the ultrasonication-, and/or microwave-, and/or radiation-regenerator 14 and regenerated under the conditions of ultrasonication, 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 may be transformed into by-products of liquid sulfur dioxide and/or sulfur trioxide of high purity by a certain processing means. Meanwhile, sulfur foams and/or dusts 8 may be produced or accumulated, and are separated from the main part of 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 ultrasonication-, 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-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.

(14) 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.

(15) In the small-sized absorption device as shown in FIG. 6, 15 represented an absorption bottle (or a regeneration bottle when regenerating), 16 represented the polyol composite solution, 17 represented the gas containing sulfur dioxide, and 18 represented a vented gas.

(16) In the small-sized heating and gas stripping-regeneration device as shown in FIG. 7, 15 represented a regeneration bottle (or an absorption bottle when absorbing), 16 represented the polyol composite solution with absorbed sulfur dioxide, 19 represented a gas for gas stripping (N.sub.2 in this test), 20 represented the stripping gas containing sulfur dioxide, 21 represented a silicone oil for oil bath, and 22 represented a thermostatic heating pot.

(17) In the experiment, as shown in FIG. 6, about 150 ml fresh polyol composite solution 16 was charged into the absorption bottle 15. A certain amount (L, liter) of gas 17 containing sulfur dioxide was blown into the absorption bottle 15 containing the polyol composite solution 16 at room temperature and passed through the polyol composite solution 16. The sulfur dioxide in the gas was absorbed by the polyol composite 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 polyol composite solution 16 was measured using iodimetry. Then, the absorption bottle containing the polyol composite 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 polyol composite solution 16 had already been measured and it could be used as the polyol composite 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 to heat 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 polyol composite solution 16 containing sulfur dioxide. At this time, the sulfur dioxide contained in the polyol composite 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 containing 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 polyol composite solution 16 was measured using iodimetry. The absorption and regeneration of the regenerated polyol composite solution 16 were repeated many times in accordance with the above steps. The changes appeared in the polyol composite solution were observed.

(18) 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 60% glycerin (glycerol)+3.3% citric acid+4% citric acid monosodium salt+32.7% H.sub.2O, a system of 60% glycerin+3% citric acid+8% citric acid monosodium salt+29% H.sub.2O, a system of 60% glycerin+8% citric acid monosodium salt+32% H.sub.2O, a system of 50% glycerin+43.5% water+6.5% EDTA disodium salt, a system of 50% glycerin+40% water+10% EDTA disodium salt, a system of 65% glycerin+20% acetic acid+13% water+2% acetic acid potassium salt, a system of 60% glycerin+30% water+7.8% oxalic acid monopotassium salt+2.2% oxalic acid, and a system of 70% glycerin+30% water. The experiment data were listed in Tables 1 to 8 respectively.

(19) TABLE-US-00001 TABLE 1 The absorption and desorption of SO.sub.2 with 60% glycerin + 3.3% citric acid + 4% citric acid monosodium salt + 32.7% H.sub.2O (150 mL) Volume of Content of Content of gas to be sulfur dioxide sulfur dioxide absorbed in the polyol in the polyol Appearance Number of (the content composite composite of the polyol times for of SO.sub.2 in the solution after solution after Regeneration composite absorption gas is about absorption regeneration temperature Regeneration solution and 1%) L C*.sub.SO2 C.sub.SO2 t time after regeneration (litre) (g/L) (g/L) (? C.) T (min) regeneration 1.sup.st 15 2.1056 0.6479 130 30 no changes 2.sup.nd 15 2.2676 0.5831 130 30 in color 3.sup.rd 15 2.1704 0.5183 130 30 3.sup.rd 15 2.2028 0.5507 130 30 5.sup.th 15 2.4295 0.2592 130 30 6.sup.th 30 3.1746 0.2592 130 30 7.sup.th 15 2.2028 0.1296 130 30 8.sup.th 15 2.3648 0.1296 130 30 9.sup.th 15 2.1056 0.1296 130 30 10.sup.th 15 2.4943 0.2592 130 30 11.sup.th 15 2.3972 0.1296 130 30 12.sup.th 15 2.6563 0.9718 130 30

(20) TABLE-US-00002 TABLE 2 The absorption and desorption of SO.sub.2 with 60% glycerin + 3% citric acid + 8% citric acid monosodium salt + 29% H.sub.2O (150 mL) Volume of Content of Content of gas to be sulfur dioxide sulfur dioxide absorbed in the polyol in the polyol Appearance Number of (the content composite composite of the polyol times for of SO.sub.2 in the solution after solution after Regeneration composite absorption gas is about absorption regeneration temperature Regeneration solution and 1%) L C*.sub.SO2 C.sub.SO2 t time after regeneration (litre) (g/L) (g/L) (? C.) T (min) regeneration 1.sup.st 15 3.3042 0.3563 130 45 no changes 2.sup.nd 15 2.5915 0.4859 130 30 in color 3.sup.rd 15 2.9802 0.5507 130 30 3.sup.rd 15 3.0774 0.5183 130 30 5.sup.th 15 2.7535 0.6479 130 30 6.sup.th 15 2.7859 0.2592 130 30 7.sup.th 15 2.6239 0.1296 130 30 8.sup.th 15 2.6563 0.1296 130 30 9.sup.th 15 2.6887 0.2592 130 30 10.sup.th 15 2.5591 0.1296 130 30 11.sup.th 15 2.5267 0.1296 130 30 12.sup.th 15 2.6563 0.2592 130 30

(21) TABLE-US-00003 TABLE 3 The absorption and desorption of SO.sub.2 with 60% glycerin + 8% citric acid monosodium salt + 32% H.sub.2O (150 mL) Volume of Content of Content of gas to be sulfur dioxide sulfur dioxide absorbed in the polyol in the polyol Appearance Number of (the content composite composite of the polyol times for of SO.sub.2 in the solution after solution after Regeneration composite absorption gas is about absorption regeneration temperature Regeneration solution and 1%) L C*.sub.SO2 C.sub.SO2 t time after regeneration (litre) (g/L) (g/L) (? C.) T (min) regeneration 1.sup.st 15 2.3972 0.1296 130 30 no changes 2.sup.nd 15 2.6563 0.9718 130 30 in color 3.sup.rd 15 3.3042 1.4577 130 30 3.sup.rd 22 4.6971 1.1014 130 30 5.sup.th 15 2.9478 1.6197 130 30

(22) TABLE-US-00004 TABLE 4 The absorption and desorption of SO.sub.2 with 50% glycerin + 43.5% H.sub.2O + 6.5% EDTA disodium salt (150 mL) Volume of Content of Content of gas to be sulfur dioxide sulfur dioxide absorbed in the polyol in the polyol Appearance Number of (the content composite composite of the polyol times for of SO.sub.2 in the solution after solution after Regeneration composite absorption gas is about absorption regeneration temperature Regeneration solution and 1%) L C*.sub.SO2 C.sub.SO2 t time after regeneration (litre) (g/L) (g/L) (? C.) T (min) regeneration 1.sup.st 15 2.7535 0.2592 130 45 The solution 2.sup.nd 17 2.4295 0.3887 130 30 became 3.sup.rd 15 2.5591 0.4535 130 30 milky white 3.sup.rd 15 2.5915 0.3239 130 30 and slightly 5.sup.th 15 3.0126 1.1338 130 30 turbid 6.sup.th 15 2.9155 0.8422 130 30 during 7.sup.th 15 3.4985 0.8746 130 30 absorption, 8.sup.th 15 3.4014 0.7775 130 30 and the 9.sup.th 15 3.4985 0.8098 130 30 solution 10.sup.th 15 3.5633 1.1014 130 30 became 11.sup.th 15 3.0774 0.6479 130 30 colorless 12.sup.th 15 2.9155 0.7127 130 30 during 13.sup.th 15 3.2394 0.7775 130 30 regeneration 14.sup.th 15 3.4014 0.6479 130 30 15.sup.th 15 3.3042 0.8098 130 30 16.sup.th 15 3.1098 0.6479 130 30 17.sup.th 15 3.0774 0.5831 130 30 18.sup.th 15 2.9155 0.7127 130 30 19.sup.th 15 3.0126 0.7451 130 30 20.sup.th 15 3.2394 0.8422 130 30 21.sup.th 15 3.0774 0.7775 130 30

(23) TABLE-US-00005 TABLE 5 The absorption and desorption of SO.sub.2 with 50% glycerin + 40% H.sub.2O + 10% EDTA disodium salt (150 mL) Volume of Content of Content of gas to be sulfur dioxide sulfur dioxide absorbed in the polyol in the polyol Appearance (the content composite composite of the polyol Number of of SO.sub.2 in the solution after solution after Regeneration composite absorption for gas is about absorption regeneration temperature Regeneration solution and 1%) L C*.sub.SO2 C.sub.SO2 t time after regeneration (litre) (g/L) (g/L) (? C.) T (min) regeneration 1.sup.st 15 3.4985 0.1296 130 45 The solution 2.sup.nd 15 2.1056 0.6479 130 30 became 3.sup.rd 15 2.7211 0.7127 130 30 milky white 3.sup.rd 15 2.7535 0.7775 130 30 and slightly 5.sup.th 15 3.5633 1.1014 130 30 turbid 6.sup.th 15 3.4014 0.7127 130 30 during 7.sup.th 15 3.2394 0.6479 130 30 absorption, 8.sup.th 15 3.1746 0.6803 130 30 and the 9.sup.th 15 3.1422 0.5831 130 30 solution 10.sup.th 15 2.7859 1.0366 130 30 became 11.sup.th 15 2.9155 0.8746 130 30 colorless 12.sup.th 15 2.8507 0.8098 130 30 during 13.sup.th 17 2.9802 0.9718 130 30 regeneration 14.sup.th 15 2.9155 0.9070 130 30 15.sup.th 15 3.0774 0.9718 130 30 16.sup.th 15 2.8507 0.5831 130 30 17.sup.th 15 2.9155 0.6479 130 30 18.sup.th 15 2.7535 0.5183 130 30 19.sup.th 15 2.8507 0.6803 130 30 20.sup.th 15 2.7535 0.6479 130 30 21.sup.th 15 2.9155 0.8098 130 30 22.sup.th 15 2.7535 0.6803 130 30

(24) TABLE-US-00006 TABLE 6 The absorption and desorption of SO.sub.2 with 65% glycerin + 20% acetic acid + 13% water + 2% acetic acid potassium salt (150 mL) Volume of Content of Content of gas to be sulfur dioxide sulfur dioxide absorbed in the polyol in the polyol Appearance Number of (the content composite composite of the polyol times for of SO.sub.2 in the solution after solution after Regeneration composite absorption gas is about absorption regeneration temperature Regeneration solution and 1%) L C*.sub.SO2 C.sub.SO2 t time after regeneration (litre) (g/L) (g/L) (? C.) T (min) regeneration 1.sup.st 15 1.3605 0.1296 130 30 no changes 2.sup.nd 15 1.9436 0.1296 130 30 in color 3.sup.rd 15 2.0732 0.1296 130 30 3.sup.rd 15 2.1056 0.1296 130 30 5.sup.th 15 2.0408 0.1296 130 30 6.sup.th 15 1.9436 0.1296 130 30 7.sup.th 15 2.0084 0.1296 130 30 8.sup.th 15 2.1056 0.1296 130 30 9.sup.th 15 2.1056 0.1296 130 30 10.sup.th 15 2.0732 0.1296 130 30

(25) TABLE-US-00007 TABLE 7 The absorption and desorption of SO.sub.2 with 60% glycerin + 30% water + 7.8% oxalic acid monopotassium salt + 2.2% oxalic acid (150 mL) Volume of Content of Content of gas to be sulfur dioxide sulfur dioxide absorbed in the polyol in the polyol Number of (the content composite composite Appearance times for of SO.sub.2 in the solution after solution after Regeneration of the polyol absorption gas is about absorption regeneration temperature Regeneration composite and 1%) L C*.sub.SO2 C.sub.SO2 t time solution after regeneration (litre) (g/L) (g/L) (? C.) T (min) regeneration 1.sup.st 15 1.6197 0.1296 130 30 The solution 2.sup.nd 15 1.6197 0.1296 130 30 became milky 3.sup.rd 15 1.5549 0.1296 130 30 white and 3.sup.rd 15 1.4577 0.1296 130 30 slightly turbid 5.sup.th 15 1.3605 0.1296 130 30 during 6.sup.th 15 1.2958 0.1296 130 30 absorption, 7.sup.th 15 1.2958 0.1296 130 30 and the 8.sup.th 15 1.2310 0.1296 130 30 solution 9.sup.th 15 1.3605 0.1296 130 30 became 10.sup.th 15 1.2958 0.1296 130 30 colorless during regeneration

(26) TABLE-US-00008 TABLE 8 The absorption and desorption of SO.sub.2 with 70% glycerin + 30% H.sub.2O (100 mL) Volume of Content of Content of gas to be sulfur dioxide sulfur dioxide absorbed in the polyol in the polyol Number of (the content composite composite Appearance times for of SO.sub.2 in the solution after solution after Regeneration of the polyol absorption gas is about absorption regeneration temperature Regeneration composite and 1%) L C*.sub.SO2 C.sub.SO2 t time solution after regeneration (litre) (g/L) (g/L) (? C.) T (min) regeneration 1.sup.st 15 1.0042 0.1296 130 30 no changes in 2.sup.nd 15 1.0366 0.1296 130 30 color 3.sup.rd 15 0.9070 0.1296 130 30 3.sup.rd 15 0.9394 0.1296 130 30 5.sup.th 15 0.9718 0.1296 130 30 6.sup.th 15 0.9070 0.1296 130 30 7.sup.th 15 0.8746 0.1296 130 30 8.sup.th 15 0.8746 0.1296 130 30 9.sup.th 15 0.8422 0.1296 130 30 10.sup.th 15 0.8422 0.1296 130 30

(27) From Table 8the absorption and desorption of SO.sub.2 with 70% glycerin+30% H.sub.2O (100 mL)it can be seen that the regeneration effect is good when a solution purely consisting of glycerin and water is used to absorb sulfur dioxide, however, the absorption capability for sulfur dioxide is poor, thus this can not be used as the desulfurization agent for sulfur dioxide in a gas.

(28) From the above experimental data in Tables 1 to 7, it can be seen that these polyol composite solutions have good effects on absorption for SO.sub.2 and regeneration. This indicates that these systems are good desulfurization solvents for flue gases.