CN-121971977-A - Dimethyl sulfide tail gas two-stage absorption system and method based on hydrogen peroxide oxidation and DMSO trapping

CN121971977ACN 121971977 ACN121971977 ACN 121971977ACN-121971977-A

Abstract

The invention discloses a dimethyl sulfide tail gas two-stage absorption system and method based on hydrogen peroxide oxidation and DMSO trapping, and relates to the technical field of waste gas purification. The system comprises a falling film absorption tower and a sulfoxide absorption tower which are connected in series through a gas connecting pipeline, wherein a first tower kettle is arranged at the bottom of the falling film absorption tower, hydrogen peroxide is sprayed to the inner wall of a tube array through a circulating pump to form a liquid film, so that dimethyl sulfide is oxidized into dimethyl sulfoxide, the sulfoxide absorption tower is a filler tower, and DMSO in the tower kettle is subjected to countercurrent physical dissolution and trapping through circulating spraying. In the treatment process, 7 ℃ low-temperature water is introduced into the falling film tower shell side, the temperature is controlled to be less than or equal to 30 ℃, and the jacket of the tower kettle of the sulfoxide tower is maintained at 25-30 ℃. The invention does not need active carbon, does not produce hazardous waste, has the total removal rate of dimethyl sulfide more than or equal to 99.9 percent, has the outlet concentration lower than 0.5 ppm, has no peculiar smell, and has the advantages of high efficiency, stability, cleanness and strong engineering applicability.

Inventors

Lei Huhu
XU XIANGFENG
JI SHENGJUN
MA YONG
Wang Cuipeng
WU KAIXUAN

Assignees

五恒化学(平顶山)有限公司

Dates

Publication Date: 20260505
Application Date: 20251227

Claims (9)

1. The dimethyl sulfide tail gas two-stage absorption system based on hydrogen peroxide oxidation and DMSO trapping is characterized by comprising a falling film absorption tower (1) and a sulfoxide absorption tower (2), wherein the falling film absorption tower (1) and the sulfoxide absorption tower (2) are in gas circuit communication through a gas connection pipeline (3); the falling film absorption tower (1) is of a tubular structure, a tubular structure is vertically arranged, an upper end opening of the falling film absorption tower is communicated with a tower top gas phase space, a methyl sulfide tail gas inlet (11) is formed in the top of the falling film absorption tower (1) and used for introducing methyl sulfide tail gas into the upper end of the tubular structure to enable gas to flow along the inner wall of the tubular structure from top to bottom, a first tower kettle (15) is arranged at the bottom of the falling film absorption tower (1), a hydrogen peroxide supplementing opening (12) is formed in one side of the top of the first tower kettle (15), one side of the bottom of the first tower kettle (15) is respectively connected with inlets of a first circulating pump main pump (18) and a first circulating pump standby pump (19) through a first circulating suction pipe (16), outlets of the first circulating pump main pump (18) and the first circulating pump standby pump (19) are connected to a liquid distributor at the top of the falling film absorption tower (1) through a first circulating spray pipe (17), a second tower kettle (21) is arranged at the bottom of the falling film absorption tower (2), a jacket cooling jacket (22) is arranged at the outer side of the second tower kettle (21), and a jacket (221) is arranged at the lower part of the cooling jacket (221) The upper part of the sulfoxide absorption tower is provided with a jacket cooling water outlet (222), one side of the top of the second tower kettle (21) is provided with a DMSO supplementing port (23), one side of the bottom of the second tower kettle (21) is respectively connected with inlets of a second circulating pump main pump (26) and a second circulating pump standby pump (27) through a second circulating suction pipe (24), outlets of the second circulating pump main pump (26) and the second circulating pump standby pump (27) are connected to a spraying device at the top of the sulfoxide absorption tower (2) through a second circulating spray pipe (25), one end of a gas connecting pipeline (3) is connected with a bottom gas outlet of the falling film absorption tower (1), the other end of the gas connecting pipeline is connected with a bottom gas inlet of the sulfoxide absorption tower (2), and the top of the sulfoxide absorption tower (2) is provided with a purified tail gas discharge port (28).
2. The dimethyl sulfide tail gas two-stage absorption system according to claim 1, wherein the volumes of the first tower kettle (15) and the second tower kettle (21) are 3m 3.
3. The dimethyl sulfide tail gas two-stage absorption system according to claim 1, wherein a cooling water inlet (13) is formed in the lower part of a shell side of the falling film absorption tower (1), a cooling water outlet (14) is formed in the upper part of the shell side, the cooling water inlet (13) is connected with a 7-DEG C low-temperature water supply pipe network, and the cooling water outlet (14) is connected with a cooling water backflow pipe network.
4. The dimethyl sulfide tail gas two-stage absorption system according to claim 1, wherein the jacket cooling water inlet (221) and the jacket cooling water outlet (222) are connected with a temperature-adjustable circulating cooling water system.
5. The dimethyl sulfide tail gas two-stage absorption system according to claim 1, wherein a liquid level meter, a temperature sensor and a liquid discharge valve are respectively arranged on the first tower kettle (15) and the second tower kettle (21).
6. A method of treating a tail gas comprising dimethyl sulfide using a two-stage absorption system according to any one of claims 1 to 5, comprising the steps of: S1, adding 27.5% of hydrogen peroxide to a first tower kettle (15) through a hydrogen peroxide supplementing port (12) to enable the volume of liquid in the first tower kettle (15) to reach 50% of the volume of the first tower kettle, and adding dimethyl sulfoxide with the purity of more than or equal to 99% to a second tower kettle (21) through a DMSO supplementing port (23) to enable the volume of liquid in the second tower kettle (21) to reach 50% of the volume of the second tower kettle; S2, starting a first circulating pump main pump (18) or a first circulating pump standby pump (19), pumping hydrogen peroxide from a first tower kettle (15) through a first circulating suction pipe (16) by using the circulating pump, conveying the hydrogen peroxide to a liquid distributor at the top of a falling film absorption tower (1) through a first circulating spray pipe (17), forming a liquid film flowing downwards on the inner wall of a tube side, simultaneously starting a second circulating pump main pump (26) or a second circulating pump standby pump (27), pumping dimethyl sulfoxide from a second tower kettle (21) through a second circulating suction pipe (24) by using the circulating pump, conveying the dimethyl sulfoxide to a spray device at the top of a sulfoxide absorption tower (2) through a second circulating spray pipe (25), and wetting a filler layer; S3, enabling tail gas containing dimethyl sulfide to enter a tube side from the top of the falling film absorption tower (1) through a dimethyl sulfide tail gas inlet (11), enabling the tail gas to flow from top to bottom, enabling the tail gas to contact with a hydrogen peroxide liquid film from top to bottom in the same direction, generating an oxidation reaction, enriching the generated methyl sulfoxide and water in a circulating absorption liquid of a first tower kettle (15), and discharging unreacted trace dimethyl sulfide along with the tail gas to form primarily purified tail gas; S4, enabling the tail gas subjected to preliminary purification in the step S3 to enter the bottom of a sulfoxide absorption tower (2) through a gas connecting pipeline (3), enabling the tail gas to be in countercurrent contact with dimethyl sulfoxide sprayed from top to bottom in a packing layer, and physically dissolving and capturing residual dimethyl sulfide; S5, exhausting the tail gas purified in the step S4 into the atmosphere from a purified tail gas exhaust port (28); S6, discharging the waste hydrogen peroxide in the first tower kettle (15) and the enriched dimethyl sulfoxide in the second tower kettle (21) to a front system respectively through a liquid discharge valve every 7 days, and supplementing fresh absorption liquid through a hydrogen peroxide supplementing port (12) and a DMSO supplementing port (23).
7. The method according to claim 6, wherein in the step S3, the low temperature water at 7 ℃ is introduced through the shell side of the falling film absorption tower (1), and the reaction temperature in the tower is controlled below 30 ℃.
8. The method according to claim 6, wherein in the step S4, circulating cooling water is introduced through a tower kettle jacket (22), and the temperature of the tower kettle of the sulfoxide absorption tower (2) is maintained at 25-30 ℃.
9. The method according to claim 6, wherein the packing set in the step S4 is structured packing or random packing, and is one selected from pall rings, raschig rings, stepped rings and wire mesh packing.

Description

Dimethyl sulfide tail gas two-stage absorption system and method based on hydrogen peroxide oxidation and DMSO trapping Technical Field The invention belongs to the technical field of waste gas purification, and particularly relates to a dimethyl sulfide tail gas two-stage absorption system and a treatment method based on the synergistic effect of hydrogen peroxide oxidation and dimethyl sulfoxide (DMSO) physical trapping. Background Dimethyl sulfide (also called as dimethyl sulfide, CH 3SCH3) is a volatile organic sulfur compound with strong malodor, and is widely used in chemical industry, pharmacy industry, pesticide industry, sewage treatment industry and other industries. Because of its extremely low olfactory threshold (about 0.001 ppm), even a minute amount of emissions can cause significant odors, severely affecting the surrounding environment and the life of the resident, and therefore is classified as one of the pollutants strictly regulated by malodorous pollutant emission standards (GB 14554-93). At present, the conventional method for industrially treating the tail gas containing the dimethyl sulfide mostly adopts a combined process of water absorption and activated carbon adsorption, namely, the tail gas is firstly introduced into a water absorption tower, partial soluble components are preliminarily washed by water, and then residual organic matters are adsorbed and purified by an activated carbon adsorption box and then discharged. However, the process has certain defects that firstly, the solubility of the dimethyl sulfide in water is extremely low (about 6.8 g/L at 20 ℃), the dimethyl sulfide belongs to organic matters which are difficult to dissolve in water, the removal efficiency of a water absorption tower is limited, the single-stage water washing removal rate is usually less than 30%, a large amount of unabsorbed dimethyl sulfide directly enters a subsequent activated carbon system, an adsorbent is saturated rapidly, the service life of the activated carbon is greatly shortened, and the operation cost is increased. In actual operation, even if the active carbon is replaced regularly, the tail gas outlet is still accompanied with obvious sulfide odor, and the emission standard is difficult to be stably reached. In addition, the technology only depends on physical absorption and adsorption, does not carry out chemical conversion on the dimethyl sulfide, can not radically eliminate the malodor characteristic of the dimethyl sulfide, and the waste activated carbon needs special treatment, thereby bringing double pressures of environmental protection and economy. Although research has been attempted to convert dimethyl sulfide into odorless or low-odor dimethyl sulfoxide (DMSO) by adopting a hydrogen peroxide (H 2O2) oxidation method, the single oxidation absorption tower is difficult to realize deep purification due to the reasons of exothermic reaction, uneven liquid film distribution, insufficient residence time and the like, and trace dimethyl sulfide still remains in tail gas, so that the problem of odor cannot be thoroughly solved. Therefore, development of an efficient, stable and sustainable dimethyl sulfide tail gas treatment technology is needed, and not only can main pollutants be converted through chemical oxidation, but also residual micro components can be deeply trapped, so that no peculiar smell of the discharged tail gas is ensured, and clean discharge is truly realized. Disclosure of Invention In view of the above, the invention provides a two-stage dimethyl sulfide tail gas absorption system and method based on hydrogen peroxide oxidation and DMSO trapping, which solve the problems of low dimethyl sulfide removal efficiency, obvious tail gas odor, high operation cost and easy secondary pollution in the prior art. In order to achieve the above purpose, the present invention provides the following technical solutions: the invention provides a dimethyl sulfide tail gas two-stage absorption system based on hydrogen peroxide oxidation and DMSO trapping, which comprises a falling film absorption tower and a sulfoxide absorption tower, wherein the falling film absorption tower is in gas circuit communication with the sulfoxide absorption tower through a gas connection pipeline. The falling film absorption tower is of a tube type structure, an inner tube is vertically arranged, an upper end opening of the falling film absorption tower is communicated with a tower top gas phase space, a methyl sulfide tail gas inlet is formed in the top of the falling film absorption tower and used for introducing tail gas containing methyl sulfide into the upper end of the tube so that gas flows from top to bottom along the inner wall of the tube, a first tower kettle is arranged at the bottom of the falling film absorption tower, a hydrogen peroxide supplementing opening is formed in one side of the top of the first tower kettle and used for supplementing 27.5% hydrogen peroxide solution, one