Treatment system and process for odorless emission of sulfur-containing waste gas

Abstract

The invention relates to the technical field of sulfur-containing waste gas treatment, in particular to a treatment system and process for odorless emission of sulfur-containing waste gas. A treatment system for odorless emission of sulfur-containing waste gas comprises an absorption tower and a desulfurization tower, and a stripping tower and a high-temperature oxidation furnace are sequentially communicated between the absorption tower and the desulfurization tower. The invention discloses a treatment process for odorless emission of sulfur-containing waste gas. The treatment process comprises the following steps: S1, an absorption and concentration stage; s2, a high-temperature oxidation stage; and S3, a desulfurization stage. The problems that in the prior art, odorless emission of large-air-volume low-concentration sulfur-containing gas cannot be achieved, and the occupied area of the device can also be reduced can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of sulfur-containing waste gas treatment, and in particular to a treatment system and process for odorless emission of sulfur-containing waste gas. Background Art

[0002] Since the chemical fiber industry mostly uses dimethyl sulfoxide as a solvent, and dimethyl sulfoxide decomposes into mercaptans or thioethers during use, chemical fiber companies will produce large amounts of low-concentration sulfur-containing waste gas containing odorous components such as thioethers and mercaptans during the molding and drying of spinning products. Since the odor of sulfur-containing waste gas is particularly obvious, it is easy to cause public pollution and even seriously endanger human health and the peace and comfort of life. Therefore, it is necessary to treat the sulfur-containing waste gas generated by the industry to achieve odorless emissions.

[0003] At present, the treatment methods for sulfur-containing waste gas mostly adopt absorption process or direct incineration oxidation process. For the absorption process, it uses sodium hydroxide aqueous solution to absorb the sulfur-containing components in the waste gas according to the acid-base neutralization principle, so as to achieve the treatment of sulfur-containing waste gas. However, the inventors have found in practice that although sodium hydroxide solution has a certain absorption effect on the acidic sulfur components in the waste gas, it is difficult to control the residual amount of sulfur-containing components to below 5ppm. Therefore, the stench of the waste gas is only improved, and completely odorless emission cannot be achieved. For the incineration oxidation process, its principle is to directly send the sulfur-containing waste gas into the incinerator for high-temperature oxidation, so as to achieve odorless emission. However, the inventors found that when this scheme is used to treat large-volume and low-concentration sulfur-containing waste gas, it is necessary to build a larger incinerator to adapt to the high-temperature oxidation of large-volume sulfur-containing waste gas, which has the problems of large construction area and high operating costs.

[0004] Therefore, the existing technology has the problem that it is difficult to achieve odorless emission of large-volume and low-concentration waste gas while reducing the floor space of the device. Summary of the invention

[0005] The present invention provides a treatment system and process for odorless emission of sulfur-containing waste gas, which can solve the problem in the prior art that it is not possible to achieve odorless emission of low-concentration sulfur-containing gas with a large air volume while reducing the area occupied by the device.

[0006] This application provides the following technical solutions:

[0007] A treatment system for odorless emission of sulfur-containing waste gas comprises an absorption tower and a desulfurization tower, wherein a stripping tower and a high-temperature oxidation furnace are connected in sequence between the absorption tower and the desulfurization tower.

[0008] Technical principles and beneficial effects:

[0009] 1. This scheme is conducive to the odorless emission of low-concentration sulfur-containing gas by sequentially setting up an absorption tower, a stripping tower, a high-temperature oxidation furnace and a desulfurization tower: First, the low-concentration sulfur-containing waste gas is passed into the absorption tower, and the sulfide in the waste gas is absorbed by the absorption liquid of the absorption tower, producing sulfur-free waste gas and sulfur-containing absorption liquid, thereby achieving the preliminary separation of the sulfur-containing waste gas. For the generated sulfur-free waste gas, because it does not contain odorous components, it is directly discharged into the atmosphere; for the sulfur-containing absorption liquid, it is transported to the stripping tower, and through the separation and purification of the stripping tower, regenerated absorption liquid and high-concentration sulfur-containing waste gas are produced. Then, the high-concentration sulfur-containing waste gas is passed into the high-temperature oxidation furnace, so that the sulfides that are difficult to absorb, such as sulfur dioxide, are oxidized at high temperature into sulfur trioxide that is easy to absorb, thereby improving the subsequent desulfurization efficiency and desulfurization effect. Finally, the sulfur trioxide mixed gas passes through the desulfurization tower, reacts with the absorbent and generates sulfate to achieve salt solidification treatment of the sulfur trioxide, and then achieves odorless emission of large air volume and low concentration sulfur-containing gas.

[0010] 2. This scheme is conducive to significantly reducing the processing gas volume of the high-temperature oxidation furnace by sequentially setting an absorption tower and a stripping tower in front of the high-temperature oxidation furnace, using a smaller high-temperature oxidation furnace, and effectively reducing the footprint of the device: Compared with the prior art, this scheme uses two treatments to achieve the reduction of the processing gas volume of the high-temperature oxidation furnace. The first treatment: passing a large amount of low-concentration sulfur-containing waste gas into the absorption tower, so that the sulfur-containing waste gas is absorbed by the absorption liquid of the absorption tower, and the sulfur-free waste gas is separated, thereby achieving the first reduction in the processing gas volume of the subsequent high-temperature oxidation furnace. The second treatment: passing the sulfur-containing absorption liquid into the stripping tower, and allowing it to be analyzed and separated to produce regenerated absorption liquid and high-concentration sulfur-containing waste gas, so as to increase the concentration of the sulfur-containing waste gas, thereby achieving the second reduction in the processing gas volume of the subsequent high-temperature oxidation furnace. This scheme sets an absorption tower and a stripping tower, so that the large-volume low-concentration sulfur-containing waste gas is converted into a small-volume high-concentration sulfur-containing waste gas, which greatly reduces the processing gas volume of the high-temperature oxidation furnace, helps to use a smaller high-temperature oxidation furnace, and thus effectively reduces the footprint of the device.

[0011] 3. In this scheme, the absorption liquid is recycled and regenerated through the decomposition of the stripping tower. In the stripping tower, the sulfur-containing absorption liquid is decomposed and separated to produce regenerated absorption liquid, which can be refluxed from the stripping tower to the absorption tower, thereby realizing the recycling of the absorption liquid and helping to reduce operating costs.

[0012] Furthermore, the liquid outlet of the absorption tower is connected to the liquid inlet of the stripping tower through a liquid delivery pipeline; the liquid outlet of the stripping tower and the upper part of the absorption tower are connected through an absorption liquid circulation pipeline.

[0013] Beneficial effects: The scheme is connected by a liquid delivery pipeline, which is helpful to transfer the sulfur-containing absorption liquid in the absorption tower to the stripping tower; in addition, since the sulfur-containing absorption liquid can produce regenerated absorption liquid under the analysis and separation action of the stripping tower, the scheme can return the regenerated absorption liquid from the stripping tower to the absorption tower by setting an absorption liquid circulation transfer pipeline, thereby realizing the recycling of the absorption liquid, which is beneficial to reducing operating costs.

[0014] Furthermore, the absorption tower, stripping tower and desulfurization tower are respectively provided with absorption liquid reflux branch pipes; and the absorption liquid reflux branch pipes are all provided with pumps for refluxing the absorption liquid at the bottom of the tower to the upper part of the tower.

[0015] Beneficial effects: Through the setting of the absorption liquid reflux branch pipe and the pump, on the one hand, this scheme can make the absorption liquid at the bottom of the tower flow back to the top of the tower and spray down from the top of the tower again, which is helpful for the absorption liquid to be fully mixed with the sulfur-containing waste gas, thereby ensuring the absorption effect of the absorption tower, the decomposition effect of the stripping tower and the desulfurization effect of the desulfurization tower; on the other hand, it is conducive to the recycling of the absorption liquid, thereby helping to reduce operating costs.

[0016] Furthermore, an absorbent cooler is provided on the absorption liquid reflux branch pipe of the absorption tower, and the connection point between the absorption liquid reflux branch pipe and the absorption tower is lower than the connection point between the absorption liquid circulation transfer pipeline and the absorption tower.

[0017] Beneficial effects: This scheme helps to enhance the absorption effect of the absorption tower by setting up an absorbent cooler: since the absorption process is an exothermic process, when the temperature of the absorption liquid in the absorption tower is low, the absorption liquid can more fully absorb the sulfur-containing waste gas and the absorption effect is better; in addition, if no measures are taken to cool down, the temperature of the absorption liquid will rise, causing the properties of the absorption liquid to change, making the absorption effect of the absorption tower worse.

[0018] Furthermore, an absorption liquid heater is provided on the absorption liquid reflux branch pipe of the stripping tower, and the absorption liquid circulation transfer pipeline is connected to the absorption liquid reflux branch pipe of the stripping tower.

[0019] Beneficial effect: This scheme helps to enhance the stripping effect of the stripping tower by setting up an absorption liquid heater: since the stripping effect of the stripping tower is better when the absorption liquid temperature is higher, this scheme heats the reflux absorption liquid through the absorbent heater, and then increases the temperature of the absorption liquid, making the stripping effect better.

[0020] Furthermore, an absorption liquid replenishing pipe and a sewage discharge pipe are provided on the absorption liquid reflux branch pipe of the desulfurization tower.

[0021] Beneficial effects: This scheme helps to replenish the absorption liquid to the desulfurization tower in time through the setting of the absorption liquid replenishing pipe, thereby ensuring the desulfurization effect of the desulfurization tower. In addition, this scheme helps to discharge the sulfate wastewater in the desulfurization tower in time through the setting of the sewage discharge pipe, so that the absorption liquid accounts for a larger proportion in the solution, further ensuring the desulfurization effect of the desulfurization tower.

[0022] Furthermore, the top of the stripping tower is connected to the high-temperature oxidation furnace through a first gas delivery pipeline, and a vacuum pump is provided on the first gas delivery pipeline; the high-temperature oxidation furnace is connected to the lower part of the desulfurization tower through a second gas delivery pipeline.

[0023] Beneficial effects: This solution achieves communication between the top of the stripping tower and the high-temperature oxidation furnace and between the high-temperature oxidation furnace and the lower part of the desulfurization tower by setting the first and second gas delivery pipelines. In addition, since the solubility of the gas decreases with the increase of pressure, when the analysis pressure in the stripping tower is high, the amount of high-concentration sulfur-containing waste gas obtained by analysis is small. This solution provides a vacuum pump in the first gas delivery pipeline, which is conducive to maintaining the analysis pressure in the stripping tower in a negative pressure state, thereby increasing the amount of high-concentration sulfur-containing waste gas obtained by analysis, which is beneficial for subsequent further processing.

[0024] Furthermore, it also includes an electrically connected controller, a liquid level sensor and a regulating valve, wherein the controller controls the opening and closing of the regulating valve according to the signal of the liquid level sensor; the lower part of the absorption tower, the stripping tower and the desulfurization tower are all provided with the liquid level sensor; the liquid conveying pipeline, the absorption liquid circulation pipeline and the sewage discharge pipe are all provided with the regulating valve.

[0025] Beneficial effects: Such a setting is conducive to controlling the flow rate, flow rate and other parameters of the liquid delivery pipeline, the absorption liquid circulation transfer pipeline, and the sewage discharge pipe, ensuring the circulation and stability of the liquid medium in the absorption tower, the stripping tower, and the desulfurization tower, thereby ensuring the absorption effect of the absorption tower, the stripping effect of the stripping tower, and the desulfurization effect of the desulfurization tower.

[0026] A process for treating odorless emission of sulfur-containing waste gas, using the above-mentioned system for treating odorless emission of sulfur-containing waste gas, comprises the following steps:

[0027] S1: In the absorption and concentration stage, the low-concentration sulfur-containing waste gas is countercurrently contacted with the absorption liquid in the absorption tower and subjected to absorption treatment to produce sulfur-free waste gas and absorption liquid containing sulfide. The sulfur-free waste gas is discharged into the atmosphere through the exhaust pipe of the absorption tower, while the absorption liquid containing sulfide is passed into the stripping tower and subjected to analysis and separation treatment to produce regenerated absorption liquid and high-concentration sulfur-containing gas; the regenerated absorption liquid flows into the absorption tower through the absorption liquid circulation transfer pipeline;

[0028] S2: High-temperature oxidation stage, high-concentration sulfur-containing gas is oxidized at high temperature in the high-temperature oxidation furnace to form sulfur trioxide mixed gas;

[0029] S3: In the desulfurization stage, the sulfur trioxide mixed gas contacts the absorption liquid in a countercurrent manner in the desulfurization tower and undergoes desulfurization treatment to produce sulfur-free waste gas and sulfur-containing waste liquid; the sulfur-free waste gas is discharged into the atmosphere through the desulfurization tower waste gas discharge pipe, and the sulfur-containing waste liquid is discharged through the sewage discharge pipe.

[0030] Technical principles and beneficial effects:

[0031] This scheme realizes odorless emission of large-volume sulfur-containing waste gas by sequentially carrying out absorption concentration, high-temperature oxidation, and desulfurization processes. In the absorption concentration stage, the sulfur-containing waste gas is passed into the absorption tower and countercurrently contacts with the absorption liquid, so that the gas-liquid contact area is increased, the gas-liquid mixing is more uniform, and the absorption efficiency is higher. During the absorption process, sulfur-free waste gas and absorption liquid containing sulfide are generated. As for the generated sulfur-free waste gas, because it does not contain odorous components, it is directly discharged into the atmosphere, thereby realizing the preliminary separation of the sulfur-containing waste gas; and for the absorption liquid containing sulfide, it is transported to the stripping tower, and through the separation and purification of the stripping tower, regenerated absorption liquid and high-concentration sulfur-containing waste gas are generated. By setting up an absorption tower and a stripping tower, this scheme converts a large-volume, low-concentration sulfur-containing waste gas into a small-volume, high-concentration sulfur-containing waste gas, greatly reducing the amount of gas to be treated by the high-temperature oxidation furnace. In the high-temperature oxidation stage, high-concentration sulfur-containing waste gas is introduced into the high-temperature oxidation furnace to oxidize sulfur dioxide and other sulfides that are difficult to absorb into sulfur trioxide that is easy to absorb at high temperature, thereby improving the subsequent desulfurization efficiency and desulfurization effect. Finally, in the desulfurization stage, the sulfur trioxide mixed gas is introduced into the desulfurization tower to react with the desulfurizer to generate sulfate, thereby achieving salt solidification of sulfur trioxide and achieving odorless emission of large-volume sulfur-containing gas.

[0032] Furthermore, the desorption pressure in the stripping tower is -80 to 10 kPa.

[0033] Beneficial effect: The inventor has found through extensive research that when the decomposition pressure of the stripping tower is -80 to 10 kpa, the decomposition effect can be improved, so that the sulfur-containing absorption liquid can more fully decompose the high-concentration sulfur-containing waste gas, thereby improving the separation effect of the stripping tower. At the same time, the regenerated absorption liquid has fewer impurities and is purer, which is more conducive to the recycling of the regenerated absorption liquid. When the decomposition pressure of the stripping tower is greater than 10, the inventor found that due to the excessive decomposition pressure, the gas volume of the high-concentration sulfur-containing waste gas obtained by decomposition in the stripping tower is reduced, and the regenerated absorption liquid has more impurities, resulting in poor decomposition effect of the stripping tower, which is not conducive to subsequent treatment; when the decomposition pressure of the stripping tower is less than -80 kpa, the inventor found that due to the too low decomposition pressure, the absorption solvent loss increases, and the operating cost increases relatively. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the structure of a system for odorless emission of sulfur-containing waste gas in Example 1 of the present invention. DETAILED DESCRIPTION

[0035] The following is further described in detail through specific implementation methods:

[0036] The symbols in the drawings of the specification include: absorption tower 10, absorption tower waste gas exhaust pipe 11, absorption tower waste gas inlet pipe 12, absorption tower absorption liquid reflux branch pipe 13, absorption tower liquid level sensor 14, absorption tower circulation pump 15, liquid delivery pipeline regulating valve 16, stripping tower 20, stripping gas inlet pipe 21, stripping tower absorption liquid reflux branch pipe 22, stripping tower liquid level sensor 23, stripping tower circulation pump 24, absorption liquid circulation transfer pipeline regulating valve 25, high temperature oxidation furnace 30, desulfurization tower 40, desulfurization tower waste gas exhaust Pipe 41, absorption liquid replenishment pipe 42, desulfurization tower liquid level sensor 43, desulfurization tower circulation pump 44, sewage discharge pipe regulating valve 45, sewage discharge pipe 46, desulfurization tower absorption liquid reflux branch pipe 47, absorbent cooler 50, cooling water inlet pipe 51, cooling water outlet pipe 52, absorption liquid heater 60, heating medium inlet pipe 61, heating medium outlet pipe 62, liquid delivery pipeline 71, absorption liquid circulation transfer pipeline 72, first gas delivery pipeline 73, second gas delivery pipeline 74, vacuum pump 80.

[0037] Example 1

[0038] like Figure 1 As shown, a system for treating odorless emission of sulfur-containing waste gas comprises an absorption tower 10, a stripping tower 20, a high-temperature oxidation furnace 30 and a desulfurization tower 40 which are sequentially connected by pipelines. Specifically, a liquid delivery pipeline 71 is connected between a liquid outlet of the absorption tower 10 arranged at the bottom of the absorption tower 10 and a liquid inlet of the stripping tower 20 arranged at the upper middle part of the stripping tower 20, an absorption liquid circulation pipeline 72 is connected between the liquid outlet of the stripping tower 20 arranged at the bottom of the stripping tower 20 and a high-position liquid inlet of the absorption tower 10 arranged at the top of the absorption tower 10, a first gas delivery pipeline 73 is connected between the air outlet of the stripping tower 20 arranged at the top of the stripping tower 20 and the air inlet of the high-temperature oxidation furnace 30, and a second gas delivery pipeline 74 is connected between the air outlet of the high-temperature oxidation furnace 30 and the air inlet of the desulfurization tower 40 arranged at the bottom of the desulfurization tower 40.

[0039] In this embodiment, the absorption tower 10 is specifically a packed absorption tower 10, and the absorption tower 10 is provided with a high-position liquid inlet of the absorption tower 10 near the top, a low-position liquid inlet of the absorption tower 10 located in the upper middle part, an air outlet of the absorption tower 10 located at the top, an air inlet of the absorption tower 10 located near the bottom, and a liquid outlet located at the bottom of the absorption tower 10. A wire mesh demister (not shown) is provided at the top of the absorption tower 10, the air inlet of the absorption tower 10 is connected to an absorption tower waste gas inlet pipe 12, and the air outlet of the absorption tower 10 is connected to an absorption tower waste gas exhaust pipe 11. At the same time, the liquid delivery pipeline 71 connected to the liquid outlet of the absorption tower 10 is provided with an absorption tower circulation pump 15 and a liquid delivery pipeline regulating valve 16 in sequence along the liquid delivery direction. An absorption tower absorption liquid reflux branch pipe 13 is provided between the absorption tower circulation pump 15 and the liquid delivery pipeline regulating valve 16 and connected to the liquid delivery pipeline 71. The absorption tower absorption liquid reflux branch pipe 13 is connected to the low-level liquid inlet of the absorption tower 10, and a spray pipe is extended in the absorption tower 10 to realize the recycling and one-time absorption of the absorption liquid in the absorption tower 10. At the same time, an absorption tower liquid level sensor 14 is provided on the right side of the bottom of the absorption tower 10, and a first controller is integrally provided with the liquid delivery pipeline regulating valve 16. The absorption tower liquid level sensor 14 is electrically connected to the first controller, and the first controller is electrically connected to the liquid delivery pipeline regulating valve 16, so that the first controller can control the switch of the liquid delivery pipeline regulating valve 16 according to the signal of the absorption tower liquid level sensor 14. In addition, the absorption tower absorption liquid reflux branch pipe 13 is provided with an absorbent cooler 50 to improve the absorption effect of the absorption tower 10. The absorbent cooler 50 is specifically a plate heat exchanger, and is connected to a cooling water inlet pipe 51 and a cooling water outlet pipe 52 .

[0040] In this embodiment, the stripping tower 20 is specifically a packed tower, such as Figure 1As shown, the stripping tower 20 is provided with a left liquid inlet of the absorption tower 10 located in the upper middle part and on the left side of the stripping tower 20, a gas outlet of the stripping tower 20 located at the top of the stripping tower 20, a liquid outlet of the stripping tower 20 located at the bottom of the stripping tower 20, a gas inlet of the stripping tower 20 located near the bottom, and a right liquid inlet of the absorption tower 10 located in the upper middle part and on the right side of the stripping tower 20. The left liquid inlet of the stripping tower 20 is connected to a liquid delivery pipeline 71, and a spray pipe extends in the stripping tower 20. The gas inlet of the stripping tower 20 is connected to a stripping gas inlet pipe 21, and the gas outlet of the stripping tower 20 is connected to a first gas delivery pipeline 73, and a vacuum pump 80 is provided on the first gas delivery pipeline 73 to reduce the decomposition pressure in the stripping tower 20. The liquid outlet of the stripping tower 20 is connected to an absorption liquid circulation transfer pipeline 72, and a stripping tower circulation pump 24 and an absorption liquid circulation transfer pipeline regulating valve 25 are sequentially arranged along the liquid conveying direction. The other end of the absorption liquid circulation transfer pipeline 72 is connected to the high-level liquid inlet of the absorption tower 10, and a spray pipe is extended into the absorption tower 10. Through the absorption liquid circulation transfer pipeline 72, the absorption liquid regenerated in the stripping tower 20 can flow back to the absorption tower 10 to achieve recycling and secondary absorption. At the same time, a stripping tower liquid level sensor 23 is arranged on the right side of the bottom of the stripping tower 20, and the absorption liquid circulation transfer pipeline regulating valve 25 is integrally provided with a second controller, the stripping tower liquid level sensor 23 is electrically connected to the second controller, and the second controller is electrically connected to the absorption liquid circulation transfer pipeline regulating valve 25, so that the second controller can control the switch of the absorption liquid circulation transfer pipeline regulating valve 25 according to the signal of the stripping tower liquid level sensor 23. In addition, a stripping tower absorption liquid reflux branch pipe 22 is provided between the stripping tower circulation pump 24 and the absorption liquid circulation transfer pipeline regulating valve 25, and the stripping tower absorption liquid reflux branch pipe 22 is connected to the second liquid inlet of the stripping tower 20 to realize the recycling of the absorption liquid in the stripping tower 20. An absorbent heater is provided on the stripping tower absorption liquid reflux branch pipe 22 to improve the decomposition effect of the stripping tower 20. The absorbent heater is specifically a plate heat exchanger, and is connected to a heating medium inlet pipe 61 and a heating medium outlet pipe 62.

[0041] The high temperature oxidation furnace 30 can be a natural gas incinerator, an electric heating furnace, etc., and the present embodiment is specifically an electric heating furnace. The high temperature oxidation furnace 30 is provided with an air inlet of the high temperature oxidation furnace 30 on the left side and an air outlet of the high temperature oxidation furnace 30 on the right side. The air inlet of the high temperature oxidation furnace 30 is connected to a first gas delivery pipeline 73, and the air outlet of the high temperature oxidation furnace 30 is connected to a second gas delivery pipeline 74.

[0042] In this embodiment, the desulfurization tower 40 is specifically an anti-clogging tower, such as Figure 1As shown, the desulfurization tower 40 is provided with a desulfurization tower 40 gas outlet located at the top of the desulfurization tower 40, a desulfurization tower 40 liquid outlet located at the bottom of the desulfurization tower 40, a desulfurization tower 40 gas inlet located near the bottom, and a desulfurization tower 40 liquid inlet located near the top. The desulfurization tower 40 gas inlet is connected to the second gas transmission pipeline 74, and the desulfurization tower 40 gas outlet is connected to the desulfurization tower exhaust gas exhaust pipe 41. A desulfurization tower absorption liquid reflux branch pipe 47 is connected between the desulfurization tower 40 liquid outlet and the desulfurization tower 40 liquid inlet, and a desulfurization tower circulation pump 44 is provided on the desulfurization tower absorption liquid reflux branch pipe 47. The absorption liquid replenishing pipe 42 is located between the desulfurization tower 40 liquid outlet and the desulfurization tower circulation pump 44 and is connected to the desulfurization tower absorption liquid reflux branch pipe 47. The sewage discharge pipe 46 is located between the desulfurization tower circulation pump 44 and the top of the desulfurization tower 40 and is connected to the desulfurization tower absorption liquid reflux branch pipe 47. The sewage discharge pipe 46 is provided with a sewage discharge pipe regulating valve 45. At the same time, a desulfurization tower liquid level sensor 43 is provided on the right side of the bottom of the desulfurization tower 40, and a third controller is integrally provided with the sewage discharge pipe regulating valve 45. The desulfurization tower liquid level sensor 43 is electrically connected to the third controller, and the third controller is electrically connected to the sewage discharge pipe regulating valve 45, so that the third controller can control the switch of the sewage discharge pipe regulating valve 45 according to the signal of the desulfurization tower liquid level sensor 43.

[0043] This embodiment also describes a treatment process for odorless emission of sulfur-containing waste gas, using the above-mentioned treatment system for odorless emission of sulfur-containing waste gas, including the following steps:

[0044] S1: Absorption and concentration stage:

[0045] The low-concentration sulfur-containing waste gas is countercurrently contacted with the alcohol amine absorption liquid in the absorption tower 10 and subjected to absorption treatment to produce sulfur-free waste gas and absorption liquid containing sulfide. The sulfur-free waste gas is discharged into the atmosphere through the absorption tower exhaust pipe 11, while the absorption liquid containing sulfide is introduced into the stripping tower 20 and subjected to separation and analysis treatment to produce regenerated absorption liquid and high-concentration sulfur-containing gas; the regenerated absorption liquid flows into the absorption tower 10 through the absorption liquid circulation transfer pipe;

[0046] Specifically, the low-concentration sulfur-containing waste gas introduced into the absorption tower 10 contains 80 ppm of methyl mercaptan, 80 ppm of methyl sulfide, and air. The absorption liquid is an alcohol amine absorption liquid, and in this embodiment, it is a mixture of one or more of polyethylene glycol dimethyl ether or N-methyldiethanolamine. The absorption treatment includes a primary absorption treatment and a secondary absorption treatment, wherein the primary absorption treatment is: the absorption liquid, under the action of the absorption tower circulation pump 15, flows back to the absorption tower 10 through the absorption tower absorption liquid reflux branch pipe 13, and sprays out from the upper part of the absorption tower 10, and then contacts with the sulfur-containing waste gas in countercurrent to absorb the sulfide therein; and the secondary absorption treatment is: the regenerated absorption liquid, under the action of the stripping tower circulation pump 24, flows back to the absorption tower 10 through the absorption liquid circulation transfer pipeline, and sprays out from the top of the absorption tower 10, contacts with the sulfur-containing waste gas in countercurrent, and absorbs the sulfide still remaining after the primary absorption treatment.

[0047] To ensure the absorption treatment effect, the temperature of the bottom of the absorption tower 10 is set to 20-60°C, the cooling temperature of the absorption liquid cooler is 15-45°C, the pressure of the absorption tower 10 is set to 5Kpa-20Kpa, the temperature of the regenerated absorption liquid is set to 10-30°C, the gas-liquid ratio of the absorption liquid sprayed from the low-position liquid inlet of the absorption tower 10 is 100-300, and the gas-liquid ratio of the regenerated absorption liquid sprayed from the high-position liquid inlet of the absorption tower 10 is 500-1500, so as to improve the effect of secondary absorption. In this embodiment, the temperature of the bottom of the absorption tower 10 is specifically 20°C, the cooling temperature of the absorption liquid cooler is specifically 15°C, the pressure of the absorption tower 10 is specifically set to 5Kpa, the temperature of the regenerated absorption liquid is specifically set to 10°C, the gas-liquid ratio of the sulfur-containing waste gas to the absorption liquid sprayed from the low-position liquid inlet of the absorption tower 10 is 100-300, and the gas-liquid ratio of the sulfur-containing waste gas to the regenerated absorption liquid sprayed from the high-position liquid inlet of the absorption tower 10 is 500-1500.

[0048] To ensure the decomposition effect of the stripping tower 20, the absorption liquid heater 60 is set to 60-120°C, the decomposition pressure is set to -80-10kPa, and the ratio of the stripping gas flow rate to the absorption liquid flow rate entering the stripping tower is 3-30. In this embodiment, the absorption liquid heater 60 has a temperature of 60°C, a decomposition pressure of -80Pa, and a ratio of the stripping gas flow rate to the absorption liquid flow rate of 3.

[0049] S2: High temperature oxidation stage:

[0050] The high-concentration sulfur-containing waste gas is oxidized at high temperature in the high-temperature oxidation furnace 30 to form a sulfur trioxide mixed gas;

[0051] Specifically, the high-concentration sulfur-containing waste gas generated by the stripping tower 20 is fed into the high-temperature oxidation furnace 30 through the first gas delivery pipeline 73 for high-temperature oxidation treatment. To ensure the high-temperature oxidation effect of the high-temperature oxidation furnace 30, the temperature of the high-temperature oxidation furnace 30 is set to 600-900°C, specifically 750°C in this embodiment.

[0052] S3: In the desulfurization stage, the sulfur trioxide mixed gas contacts the absorption liquid in the desulfurization tower 40 in countercurrent and undergoes desulfurization treatment to produce sulfur-free waste gas and sulfur-containing waste liquid; the sulfur-free waste gas is discharged into the atmosphere through the second waste gas discharge pipe, and the sulfur-containing waste liquid is discharged through the sewage discharge pipe 46.

[0053] Specifically, the sulfur trioxide mixed gas generated from the high-temperature oxidation furnace 30 is passed into the bottom of the desulfurization tower 40 through the second gas delivery pipeline 74, and countercurrently contacts with the absorption liquid sprayed from the top of the absorption tower 10, and reacts with the absorbent to generate sulfate, thereby achieving salt solidification of sulfur trioxide, and finally achieving odorless emission. In order to ensure the desulfurization effect, the temperature of the desulfurization tower 40 is set at 25-50°C, and the pressure in the desulfurization tower 40 is 5-15kpa. In this embodiment, the temperature of the desulfurization tower 40 is 25°C, and the pressure of the desulfurization tower 40 is 5-15kpa.

[0054] After implementation, the inventors found that the use of the treatment system and treatment process of this solution can achieve odorless emission of sulfur-containing waste gas with a large air volume, specifically: mercaptan <1mg / Nm 3 , sulfide <2mg / Nm 3 , meet the national emission standards and achieve green production.

[0055] Table 1 Parameter settings and implementation results of Examples 2 to 3 and Comparative Examples 1 to 9:

[0056]

[0057]

[0058]

[0059] Experimental data show that this scheme, through the treatment system of odorless emission of sulfur-containing waste gas, sequentially carries out absorption concentration, high-temperature oxidation, and desulfurization processes, to achieve odorless emission of large-volume sulfur-containing waste gas, and the overall desulfurization rate reaches more than 98.7, with significant desulfurization effect, which is far lower than the national emission standard. At the same time, this scheme ensures that the sulfur-containing waste gas is absorbed and concentrated by limiting the temperature of the absorber 10, the cooling temperature of the absorbent cooler, the temperature of the regenerated absorbent, the temperature of the absorbent heater 60, and the desorption pressure; ensures that the sulfur-containing waste gas is fully burned by setting the temperature of the high-temperature oxidation furnace 30; and ensures that the sulfur trioxide mixed gas is fully absorbed by limiting the temperature of the desulfurization tower 40, the pressure of the desulfurization tower 40, etc.

[0060] Specifically, in Examples 1 to 3, by controlling the parameters such as the bottom temperature of the absorption tower 10, the cooling temperature of the absorption liquid cooler, the pressure of the absorption tower 10, the temperature of the regenerated absorption liquid, the gas-liquid ratio of the absorption liquid sprayed from the low-level liquid inlet of the absorption tower 10, and the analytical pressure within the technical range required by this scheme, the concentration of mercaptans and sulfides discharged from the top of the absorption tower 10 can be controlled to be less than 1 mg / Nm 3 By controlling the temperature of the high-temperature oxidation furnace 30, the pressure of the desulfurization tower 40, the temperature of the desulfurization tower 40 and other parameters within the range required by this scheme, the total sulfur concentration of the exhaust gas discharged from the top of the desulfurization tower 40 can be controlled to be less than 50mg / Nm 3 The overall desulfurization rate reached above 98.7%.

[0061] Comparative Example 1 Compared with Example 2, the temperatures of the bottoms of the absorption tower 10 and the desulfurization tower 40 are too high, the temperature of the regenerated absorption liquid is too high, the desulfurization rate is reduced, and the total sulfur concentration discharged from the exhaust pipe 41 of the desulfurization tower is greatly increased;

[0062] Comparative Example 2 Compared with Example 2, the cooling temperature of the cooler is higher, the methyl sulfide and methyl mercaptan discharged from the exhaust pipe 11 of the absorption tower are greatly increased, and the desulfurization rate is reduced;

[0063] Comparative Example 3 Compared with Example 2, the heater temperature is low, the methyl sulfide and methyl mercaptan discharged from the exhaust pipe 11 of the absorption tower are greatly increased, and the desulfurization rate is reduced;

[0064] Comparative Example 4 Compared with Example 2, the pressure of the absorption tower 10 and the desulfurization tower 40 is relatively low, the desulfurization rate is reduced, and the total sulfur concentration of the exhaust gas discharged from the exhaust pipe 41 of the desulfurization tower is greatly increased;

[0065] Compared with Example 2, in Comparative Example 5, the desorption pressure is higher. Although the total sulfur concentration of the exhaust gas discharged from the exhaust pipe 41 of the desulfurization tower is reduced, the methyl sulfide and methyl mercaptan of the exhaust gas discharged from the exhaust pipe 11 of the absorption tower are greatly increased, and the desulfurization rate is reduced.

[0066] Comparative Example 6 Compared with Example 2, the temperature of the high-temperature oxidation furnace 30 is low, the desulfurization rate is reduced, and the total sulfur concentration of the exhaust gas discharged from the exhaust pipe 41 of the desulfurization tower is greatly increased;

[0067] Comparative Example 7 Compared with Example 2, the gas-liquid ratio of the absorption liquid sprayed from the low-position liquid inlet of the absorption tower 10 and the gas-liquid ratio of the regenerated absorption liquid sprayed from the high-position liquid inlet of the absorption tower 10 are lower, the desulfurization rate is reduced, and the total sulfur concentration of the exhaust gas discharged from the exhaust pipe 41 of the desulfurization tower is greatly increased;

[0068] Compared with Example 2, Comparative Example 8 has a high desulfurization gas-liquid ratio, a reduced desulfurization rate, and a greatly increased total sulfur concentration in the exhaust gas discharged from the exhaust pipe 41 of the desulfurization tower;

[0069] In Comparative Example 9 and Example 2, the values ​​of various parameters are outside the value range required by the present technical solution. The methyl sulfide and methyl mercaptan in the exhaust gas discharged from the exhaust pipe 11 of the absorption tower are greatly increased, the total sulfur concentration in the exhaust gas discharged from the exhaust pipe 41 of the desulfurization tower is greatly increased, and the desulfurization rate is reduced.

[0070] The above are only embodiments of the present invention. The invention is not limited to the field involved in this implementation case. The common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A system for odorless emission of sulfur-containing waste gas, comprising an absorption tower and a desulfurization tower, characterized in that: The stripping tower and the high-temperature oxidation furnace are connected in sequence between the absorption tower and the desulfurization tower.

2. A system for odorless emission of sulfur-containing waste gas according to claim 1, characterized in that: The liquid outlet of the absorption tower is connected to the liquid inlet of the stripping tower through a liquid delivery pipeline; the liquid outlet of the stripping tower and the upper part of the absorption tower are connected to an absorption liquid circulation pipeline.

3. A system for odorless emission of sulfur-containing waste gas according to claim 2, characterized in that: The absorption tower, stripping tower and desulfurization tower are respectively provided with absorption liquid reflux branch pipes; and the absorption liquid reflux branch pipes are all provided with pumps for refluxing the absorption liquid at the bottom of the tower to the upper part of the tower.

4. A treatment system for odorless emission of sulfur-containing waste gas according to claim 3, characterized in that: An absorbent cooler is arranged on the absorption liquid reflux branch pipe of the absorption tower, and the connection point between the absorption liquid reflux branch pipe and the absorption tower is lower than the connection point between the absorption liquid circulation transfer pipeline and the absorption tower.

5. A system for odorless emission of sulfur-containing waste gas according to claim 4, characterized in that: An absorption liquid heater is arranged on the absorption liquid reflux branch pipe of the stripping tower, and the absorption liquid circulation transfer pipeline is connected to the absorption liquid reflux branch pipe of the stripping tower.

6. A system for odorless emission of sulfur-containing waste gas according to claim 5, characterized in that: An absorption liquid replenishment pipe and a sewage discharge pipe are provided on the absorption liquid reflux branch pipe of the desulfurization tower.

7. A system for odorless emission of sulfur-containing waste gas according to claim 6, characterized in that: The top of the stripping tower is connected to the high-temperature oxidation furnace through a first gas delivery pipeline, on which a vacuum pump is provided; the high-temperature oxidation furnace is connected to the lower part of the desulfurization tower through a second gas delivery pipeline.

8. A system for odorless emission of sulfur-containing waste gas according to claim 7, characterized in that: It also includes an electrically connected controller, a liquid level sensor and a regulating valve, wherein the controller controls the opening and closing of the regulating valve according to the signal of the liquid level sensor; the lower part of the absorption tower, the stripping tower and the desulfurization tower are all provided with the liquid level sensor; the liquid conveying pipeline, the absorption liquid circulation pipeline and the sewage discharge pipe are all provided with the regulating valve.

9. A process for treating odorless sulfur-containing waste gas, characterized in that: The method of using the odorless treatment system for sulfur-containing waste gas according to claim 7 above comprises the following steps: S1: In the absorption and concentration stage, the low-concentration sulfur-containing waste gas is countercurrently contacted with the absorption liquid in the absorption tower and subjected to absorption treatment to produce sulfur-free waste gas and absorption liquid containing sulfide. The sulfur-free waste gas is discharged into the atmosphere through the exhaust pipe of the absorption tower, while the absorption liquid containing sulfide is passed into the stripping tower and subjected to analysis and separation treatment to produce regenerated absorption liquid and high-concentration sulfur-containing gas; the regenerated absorption liquid flows into the absorption tower through the absorption liquid circulation transfer pipeline; S2: High-temperature oxidation stage, high-concentration sulfur-containing gas is oxidized at high temperature in the high-temperature oxidation furnace to form sulfur trioxide mixed gas; S3: In the desulfurization stage, the sulfur trioxide mixed gas contacts the absorption liquid in a countercurrent manner in the desulfurization tower and undergoes desulfurization treatment to produce sulfur-free waste gas and sulfur-containing waste liquid; the sulfur-free waste gas is discharged into the atmosphere through the desulfurization tower waste gas discharge pipe, and the sulfur-containing waste liquid is discharged through the sewage discharge pipe.

10. The process for treating odorless sulfur-containing waste gas according to claim 8, characterized in that: The desorption pressure in the stripping tower is -80 to 10 KPa.

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