A gas holder dry gas desulfurization system

Abstract

The utility model discloses a kind of gas tank dry gas desulfurization systems.The system includes: low temperature absorption tower, in which raw material gas tank dry gas and low temperature absorption oil countercurrent contact;Primary amine liquid absorption tower, in which utilize amine liquid to remove hydrogen sulfide in dry gas after organic sulfur is removed;Hydrolysis reactor, in which carbonyl sulfur in primary absorption tail gas is hydrolyzed, and hydrolysis tail gas is obtained;Secondary amine liquid absorption tower, in which utilize lean amine liquid to remove hydrogen sulfide in hydrolysis tail gas, and after absorption, purified dry gas is obtained.The desulfurization system of the utility model can purify and remove organic sulfide and hydrogen sulfide in dry gas, reduce sulfur content in gas, and then reduce SO2 content in flue gas discharged from heating furnace of subsequent each device, ensure that heating furnace of whole plant is safe, environmental protection, high efficiency and stable operation.

Description

Technical Field

[0001] This utility model belongs to the field of energy-saving technology, specifically relating to a dry gas desulfurization system for gas holders. Background Technology

[0002] In the petroleum refining process, refining units produce a large amount of light hydrocarbon dry gas, mainly composed of hydrocarbons such as methane, ethane, ethylene, propane, and propylene, as well as non-hydrocarbon components such as H2, N2, and sulfides. Sulfides in the dry gas can be divided into two main categories: inorganic sulfur and organic sulfur, with the inorganic sulfur content typically being higher. According to the existing refinery process, the dry gas is usually first pressurized by a compressor before being sent to a desulfurization tower, and the desulfurized dry gas is then fed into the gas pipeline network. Existing desulfurization towers mostly use amine liquid desulfurization, primarily targeting the removal of hydrogen sulfide gas (inorganic sulfur). However, amine liquid desulfurization has very little effect on the removal of organic sulfur, resulting in a high total sulfur content in the gas collected and fed into the gas pipeline network after desulfurization. When this gas with a high total sulfur content is sent to the combustion furnace for combustion, it will cause a series of problems, including excessive sulfur content in the flue gas, high acid dew point temperature in the flue gas, increased heat loss in the exhaust gas, and reduced furnace thermal efficiency.

[0003] Patent CN116286089A discloses a dry gas desulfurization device and method. This method involves setting up a mercaptan conversion tower and a diesel absorption desulfurization tower. A mercaptan conversion agent is placed in the mercaptan conversion tower, and packing, a coalescing separator, and a liquid distributor are installed in the diesel absorption tower. This two-step desulfurization process efficiently removes organic sulfur from dry gas. First, the dry gas passes through the mercaptan conversion tower where, under the action of oxygen and the mercaptan conversion agent, the methanethiol in the dry gas is converted to dimethyl disulfide. Simultaneously, hydrogen sulfide is converted to elemental sulfur and adsorbed into the micropores of the mercaptan conversion agent. Then, an alkali is used to wash away the elemental sulfur from the mercaptan conversion agent. Further, the dimethyl disulfide in the dry gas is removed by diesel absorption and washing. However, this process not only generates waste alkali and solid waste pollutants but also contains other organic sulfur compounds besides mercaptans, such as carbonyl sulfur, which are difficult to convert and treat.

[0004] CN 116392947 A discloses a method for cascade desulfurization of rich gas in refineries. The method adopts a process of first mixing and desulfurizing the rich gas in refineries, and then separating and utilizing it. This method improves upon the shortcomings of existing processes that first separate the rich gas and then desulfurize it, making full use of the composition characteristics of the raw materials, increasing the desulfurization rate, and producing ultra-low sulfur rich gas products. The total sulfur content of the refined dry gas is <0.5ppm, and there is no mercaptan sulfur; the total sulfur content of the refined liquefied petroleum gas is <1ppm, and the mercaptan sulfur content is <0.2ppm; at the same time, it reduces equipment investment. Summary of the Invention

[0005] To address the problem of high total sulfur content in the gas pipeline network due to high organic sulfur content in dry gas in existing technologies, this invention provides a dry gas desulfurization system for gas holders. This system can purify and remove organic sulfides and hydrogen sulfide from the dry gas, reducing the sulfur content in the gas and consequently reducing the SO2 content in the flue gas emitted by the heating furnaces of subsequent units, ensuring the safe, environmentally friendly, efficient, and stable operation of all heating furnaces in the plant.

[0006] According to the purpose of this invention, this utility model provides a dry gas desulfurization system for gas holders.

[0007] Specifically, the aforementioned dry gas desulfurization system for gas holders includes: In a low-temperature absorption tower, the dry gas from the feed gas holder is countercurrently contacted with low-temperature absorption oil (lean absorption oil), and after absorption, rich absorption oil and dry gas after removal of organic sulfur are obtained. The first-stage amine liquid absorption tower uses amine liquid to absorb and remove hydrogen sulfide from the dry gas after the removal of organic sulfur. After the absorption is completed, rich amine liquid and first-stage absorption tail gas are obtained. A hydrolysis reactor is used to hydrolyze carbonyl sulfur in the primary absorption tail gas to obtain hydrolyzed tail gas; a hydrolysis catalyst bed is set inside the hydrolysis reactor. The secondary amine liquid absorption tower uses lean amine liquid to absorb and remove hydrogen sulfide from the hydrolysis tail gas. After the hydrolysis tail gas is absorbed in the secondary amine liquid absorption tower, purified dry gas is obtained.

[0008] Furthermore, the dry gas in the feedstock gas holder is the dry gas compressed by the gas holder compressor, with a temperature of 80~140℃ and a pressure of 0.6~1.5 MPaG; the total sulfur content of the dry gas in the feedstock gas holder is generally around 100 mg / m³. 3 The content of carbonyl sulfide in the above is 30 mg / m³. 3 The preferred carbonyl sulfide content is greater than 50 mg / m³. 3 .

[0009] Furthermore, the low-temperature absorption tower is a packed tower. The low-temperature absorption tower includes a dry gas inlet at the bottom, a rich absorbent oil outlet at the bottom, a lean absorbent oil inlet at the top, and a dry gas outlet for removed organic sulfur at the top. The operating temperature of the low-temperature absorption tower is 10~20 ℃, the absorption pressure is 0.6~1.5 MPaG, and the liquid-to-gas ratio is 40~200 L / m³. 3 Preferred concentration: 60~100 L / m 3 The absorbent oil used in the low-temperature absorption tower has an initial boiling point of 160~220℃, a final boiling point of 320~360℃, and a density of 850~950 kg / m³ at 20℃. 3 The absorbent oil can be selected from one or more of the following: ordinary second-line diesel, ordinary third-line diesel, catalytic crude diesel, and refined diesel.

[0010] Furthermore, the desulfurization system also includes a dry gas heat exchanger for heat exchange between the dry gas from the feed gas holder and the rich absorbent oil. The cold material inlet of the dry gas heat exchanger is connected to the cold material outlet of the absorbent oil heat exchanger, and the cold material outlet of the dry gas heat exchanger is connected to the rich absorbent oil pipeline. In the dry gas heat exchanger, the dry gas from the feed gas holder (80-140°C) is cooled to 40-50°C, and the rich absorbent oil from the absorbent oil heat exchanger (25-35°C) is heated to 45-60°C.

[0011] Furthermore, the desulfurization system also includes an absorbent oil heat exchanger and a cooler. The absorbent oil heat exchanger is used for heat exchange between the rich and lean absorbent oil. The cooler is used to further cool the lean absorbent oil after it has been cooled. The lean absorbent oil pipeline is connected to the hot material inlet of the absorbent oil heat exchanger, the hot material outlet of the absorbent oil heat exchanger is connected to the inlet of the cooler, and the outlet of the cooler is connected to the lean absorbent oil inlet of the low-temperature absorption tower. The rich absorbent oil outlet of the low-temperature absorption tower is connected to the cold material inlet of the absorbent oil heat exchanger, and the cold material outlet of the absorbent oil heat exchanger is connected to the cold material inlet of the dry gas heat exchanger. Heat exchange occurs between the lean and rich absorbent oils within the absorbent oil heat exchanger. After heat exchange, the temperature of the lean absorbent oil drops to approximately 30°C, and is further cooled to 10-20°C in the cooler; the temperature of the rich absorbent oil rises from 10-20°C to 25-35°C within the absorbent oil heat exchanger.

[0012] Furthermore, the desulfurization system also includes an absorption tail gas heat exchanger and a heater. The absorption tail gas heat exchanger is used for heat exchange between the primary absorption tail gas from the primary amine liquid absorption tower and the hydrolysis tail gas. The heater is used to heat the primary absorption tail gas after preheating in the absorption tail gas heat exchanger. The absorption tail gas outlet of the primary amine liquid absorption tower is connected to the cold material inlet of the absorption tail gas heat exchanger, the cold material outlet of the absorption tail gas heat exchanger is connected to the cold material inlet of the heater, and the cold material outlet of the heater is connected to the absorption tail gas inlet at the bottom of the hydrolysis reactor. The heater can be heated by steam. The absorption tail gas and the hydrolysis tail gas exchange heat in the absorption tail gas heat exchanger, and after heat exchange, the temperature of the absorption tail gas rises to 110~120℃, and is further heated to 130~140℃ by steam in the heater.

[0013] Furthermore, within the hydrolysis reactor, carbonyl sulfide is converted into hydrogen sulfide and carbon dioxide under the action of a hydrolysis catalyst, yielding hydrolysis tail gas. The hydrolysis reactor includes a bottom absorption tail gas inlet and a top hydrolysis tail gas outlet. The top hydrolysis tail gas outlet is connected to the hot material inlet of the absorption tail gas heat exchanger via a pipeline, and the bottom absorption tail gas inlet is connected to the heater outlet via a pipeline. The absorption tail gas inlet is also connected to a steam pipeline to supplement the steam required for the hydrolysis reaction. The water content in the absorption tail gas entering the hydrolysis reactor is generally controlled at 0.1~0.5 v%, preferably 0.2~0.4 v%. The water content in the absorption tail gas is adjusted by regulating the amount of steam added to the hydrolysis reactor. The reaction temperature of the hydrolysis reactor is generally 120~130℃, the operating pressure is generally 0.6~1.5 MPaG, and the gas hourly space velocity is generally 500~1200 h⁻¹. -1 The preferred gas volume hourly space velocity is 700~900. h-1 After being treated by a hydrolysis reactor, the molar conversion rate of carbonyl sulfur in the absorption tail gas can reach over 98%.

[0014] Furthermore, the hydrolysis catalyst bed in the hydrolysis reactor is a fixed bed. A gas distributor can be installed at the bottom of the hydrolysis reactor to uniformly distribute the dry gas and water vapor mixture entering the reactor. The hydrolysis catalyst can be a conventional catalyst in the art. For example, the active component of a typical hydrolysis catalyst is an alkali metal oxide. The hydrolysis catalyst is arranged in a fixed bed form inside the hydrolysis reactor. The hydrolysis catalyst typically includes a support and a supported alkali metal oxide. The support is selected from one or more of SiO2, Al2O3, X-type molecular sieves, Y-type molecular sieves, A-type molecular sieves, and granular activated carbon. The active component is selected from one or more of sodium hydroxide, calcium hydroxide, potassium hydroxide, barium hydroxide, ammonia, sodium nitrate, and potassium carbonate. The content of the active component is generally 5-20 wt%. The hydrolysis catalyst can be in the shape of a clover, four-leaf clover, strip, or sphere. The preparation of the hydrolysis catalyst is a conventional technique in the art, and the preparation process of hydrogenation catalysts can be referenced.

[0015] Furthermore, the primary and secondary amine absorption towers can be packed towers or plate towers. The primary amine absorption tower includes a lower inlet for the dry gas containing removed organic sulfur, a bottom outlet for rich amine liquid, an upper inlet for lean amine liquid, and a top outlet for the primary absorption tail gas. The dry gas inlet for removed organic sulfur of the primary amine absorption tower is connected to the dry gas outlet for removed organic sulfur of the low-temperature absorption tower; the operation of the primary and secondary amine absorption towers is conventional in the art. For example, the absorption temperature is room temperature, the absorption pressure is 0.6~1.5 MPaG, and the absorption liquid-to-gas ratio is 3~8 L / m³. 3The lean amine solution used in the secondary amine absorption tower comes from a nearby lean amine solution pipeline; the rich amine solution after the primary amine absorption tower absorbs hydrogen sulfide is sent to a nearby amine regeneration tower for regeneration and reuse through a rich amine solution pipeline.

[0016] Furthermore, the secondary amine absorption tower includes a lower hydrolysis tail gas inlet, a bottom amine liquid outlet, an upper lean amine liquid inlet, and a top purified dry gas outlet. The hydrolysis tail gas inlet of the secondary amine absorption tower is connected to the hot material outlet of the absorption tail gas heat exchanger via a pipeline. The amine liquid outlet is connected to the amine liquid inlet of the primary amine absorption tower via a pipeline and an amine liquid pump. The lean amine liquid inlet is connected to a lean amine liquid pipeline, and the purified dry gas outlet is connected to a purified dry gas pipeline. Inside the secondary amine absorption tower, the hydrogen sulfide-rich hydrolysis tail gas is countercurrently absorbed with the lean amine liquid, removing the hydrogen sulfide from the hydrolysis tail gas to obtain purified dry gas and a amine-rich liquid.

[0017] In this utility model, the cooler, heat exchanger and heater can be in the form of shell and tube heat exchanger, plate heat exchanger, etc., and all of these are well known to those skilled in the art.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. In the desulfurization system for dry gas in the gas holder of this utility model, a combined technology of low-temperature oil absorption-amine washing-hydrolysis-deep hydrogen sulfide absorption is adopted. The system first removes organic sulfur (excluding carbonyl sulfide) from the dry gas in the gas holder via a low-temperature absorption tower, then removes hydrogen sulfide via amine absorption. Next, the carbonyl sulfide in the dry gas is converted to hydrogen sulfide in a hydrolysis reactor. Finally, the hydrogen sulfide is further removed in the amine absorption tower, which can reduce the sulfide content in the dry gas to 20 mg / m³. 3 The desulfurization process of this invention significantly reduces the total sulfur content of the gas. This desulfurization process has high sulfide removal efficiency, improves the properties of the gas, and consequently reduces the SO2 content in the flue gas emitted from the heating furnaces of subsequent units, ensuring the safe, environmentally friendly, efficient, and stable operation of all heating furnaces in the plant.

[0019] 2. In the dry gas desulfurization system of this utility model, the combined technology of low-temperature oil absorption-amine washing-hydrolysis-hydrogen sulfide deep absorption is a highly efficient recovery technology. Low-temperature absorption can efficiently recover organic sulfides, with an organic sulfur recovery rate of over 98%; organic sulfur hydrolysis can achieve over 98% conversion of carbonyl sulfur; and organic amine absorption can achieve efficient absorption of hydrogen sulfide. Therefore, this technology can efficiently recover sulfur resources.

[0020] 3. In the dry gas desulfurization system of this utility model, the combined technology of low-temperature oil absorption-amine washing-hydrolysis-hydrogen sulfide deep absorption is an energy-saving technology. The two-stage amine liquid absorption adopts cascade or stepped use of amine liquid. The lean amine liquid first absorbs hydrolyzed hydrogen sulfide in the secondary amine liquid absorption tower, and then enters the primary amine liquid absorption tower to absorb hydrogen sulfide in the refinery dry gas feedstock. This saves the amount of amine liquid used, improves the effect of amine liquid absorption and removal of hydrogen sulfide, and significantly reduces the regeneration energy consumption of the amine liquid system.

[0021] 4. In the dry gas desulfurization system of this utility model, the combined process of low-temperature oil absorption-amine washing-hydrolysis-hydrogen sulfide deep absorption first removes high concentrations of hydrogen sulfide and heavy molecular organic sulfur from the refinery dry gas, ensuring the efficient conversion of carbonyl sulfur hydrolysis and enabling deep removal of organic sulfur from the dry gas.

[0022] 5. In the dry gas desulfurization system of this utility model, the dry gas first passes through low-temperature diesel absorption to remove organic sulfur other than carbonyl sulfur. This avoids the problem that organic sulfides are prone to forming thermally stable salts in the amine liquid system, which accelerates the deterioration and foaming of the amine liquid and increases the regeneration energy consumption. This improves the effect of hydrogen sulfide removal from the amine liquid in the primary amine liquid absorption tower and reduces the impact of organic sulfur on the consumption and stability of the amine liquid.

[0023] 6. In the gas holder dry gas desulfurization system of this utility model, the low-temperature oil absorption-amine washing-hydrolysis-hydrogen sulfide deep absorption combination technology is a low-energy-consumption, high-efficiency, safe and environmentally friendly recycling technology that does not generate waste. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the dry gas desulfurization system of the gas holder of this utility model.

[0025] Among them, 101-dry gas pipeline, 102-dry gas heat exchanger, 103-low temperature absorption tower, 104-lean absorption oil pipeline, 105-absorption oil heat exchanger, 106-cooler, 107-rich absorption oil pipeline, 108-absorption tail gas heat exchanger, 109-heater, 110-hydrolysis reactor, 111-steam pipeline, 112-secondary amine liquid absorption tower, 113-purified dry gas pipeline, 114-rich amine liquid pipeline, 115-lean amine liquid pipeline, 116-primary amine liquid absorption tower, 117-amine liquid pump. Detailed Implementation

[0026] The technical solution of this utility model will be further described below with reference to the accompanying drawings, but is not limited to the following embodiments. Example 1

[0027] Combination Figure 1 The dry gas desulfurization system of this utility model includes: Low-temperature absorption tower 103: The low-temperature absorption tower 103 is equipped with a dry gas inlet at the bottom, a rich absorbent oil outlet at the bottom, a lean absorbent oil inlet at the top, and a dry gas outlet for removing organic sulfur at the top. The lean absorption oil inlet of the low-temperature absorption tower is connected to the lean absorption oil pipeline 104 through the lean absorption oil pipeline 104, the cooler 106 and the absorption oil heat exchanger 105; the dry gas inlet is connected to the dry gas pipeline 101 through the pipeline and the dry gas heat exchanger 102. The dry gas outlet for removing organic sulfur from the low-temperature absorption tower is connected to the dry gas inlet for removing organic sulfur from the primary amine liquid absorption tower 116 via a pipeline; the rich absorbent outlet is connected to the absorbent oil heat exchanger 105 via the dry gas pipeline 101, and then connected to the dry gas heat exchanger and the rich absorbent oil pipeline 107. Primary amine absorption tower 116: The primary amine absorption tower 116 has an inlet for dry gas to remove organic sulfur at the bottom, a rich amine liquid outlet at the bottom, a lean amine liquid inlet at the top, and an absorption tail gas outlet at the top; the lean amine liquid inlet at the top of the primary amine absorption tower is connected to the amine liquid outlet of the secondary amine absorption tower 110 through a pipeline and an amine liquid pump 117; the rich amine liquid outlet is connected to the rich amine liquid pipeline 114; the absorption tail gas outlet of the primary amine absorption tower is connected to the cold material inlet of the absorption tail gas heat exchanger 108; the cold material outlet of the absorption tail gas heat exchanger 108 is connected to the cold material inlet of the heater 109; and the cold material outlet of the heater 109 is connected to the absorption tail gas inlet at the bottom of the hydrolysis reactor 110. Hydrolysis reactor 110: Carbonyl sulfide is hydrolyzed in the primary amine liquid absorption tail gas to generate hydrogen sulfide; after the primary amine liquid absorption tail gas completes the hydrolysis, hydrolysis tail gas is obtained; the hydrolysis reactor 110 is provided with an air inlet and a hydrolysis tail gas outlet at the top; the air inlet of the hydrolysis reactor 110 is connected to the steam pipe 111 and the primary amine liquid absorption tail gas pipe respectively; the primary amine liquid absorption tail gas pipe passes through the absorption tail gas heat exchanger 108 and the heater 109 in sequence and then connects to the air inlet of the hydrolysis reactor 110; the absorption tail gas heat exchanger 108 is used to exchange heat between the absorption tail gas and the hydrolysis tail gas, and the heater 109 is used to heat the absorption tail gas after heat exchange; Secondary amine absorption tower 112: The secondary amine absorption tower 112 has a hydrolysis tail gas inlet at the bottom, an amine liquid outlet at the bottom, a lean amine liquid inlet at the top, and a purified dry gas outlet at the top. The hydrolysis tail gas inlet of the secondary amine absorption tower 112 is connected to the hot material outlet of the absorption tail gas heat exchanger 108 via a pipeline. The amine liquid outlet is connected to the amine liquid inlet of the primary amine absorption tower 116 via a pipeline and an amine liquid pump 117. The lean amine liquid inlet is connected to the lean amine liquid pipeline, and the purified dry gas outlet is connected to the purified dry gas pipeline.

[0028] The hydrolysis reactor is equipped with a fixed bed of hydrolysis catalyst to catalyze the hydrolysis reaction of carbonyl sulfur. The hydrolysis reactor 110 can be fed from the top or the bottom. Example 2

[0029] Combination Figure 1 The working process of the dry gas desulfurization of the gas holder of this utility model is as follows: The dry gas compressed by the gas holder compressor passes through the dry gas pipeline 101 and exchanges heat with the rich absorption oil in the dry gas heat exchanger 102 before entering the lower part of the low-temperature absorption tower 103. The lean absorption oil passes through the lean absorption oil pipeline 104 and exchanges heat with the rich absorption oil in the absorption oil heat exchanger 105. After being further cooled by the cooler 106, it enters the upper part of the low-temperature absorption tower and comes into countercurrent contact with the upward-flowing dry gas. After removing organic sulfur compounds such as mercaptans, sulfides, dimethyl disulfide, and thiophene from the dry gas, it is discharged from the top organic sulfur-removed dry gas outlet. The dry gas, after being desulfurized by the low-temperature absorption tower, enters the primary amine liquid absorption tower 116. In the primary amine liquid absorption tower, hydrogen sulfide is removed from the dry gas. The gas then undergoes further heat exchange with the hydrolysis tail gas in the absorption tail gas heat exchanger 108. Finally, after being further heated by the heater 109, it mixes with steam from the steam pipe 111 and enters the hydrolysis reactor 110. Under the action of the hydrolysis catalyst, a hydrolysis reaction occurs, and the resulting hydrolysis tail gas is discharged from the hydrolysis reactor 110. After being cooled by the tail gas heat exchanger, the hydrolysis tail gas enters the secondary amine liquid absorption tower 112 from the bottom and comes into countercurrent contact with the lean amine liquid entering from the top of the secondary amine liquid absorption tower to remove the hydrogen sulfide contained in the hydrolysis tail gas. The purified gas is discharged from the top of the secondary amine liquid absorption tower.

Claims

1. A dry gas desulfurization system for a gas holder, characterized in that, include: In the low-temperature absorption tower, the dry gas from the raw material gas holder is contacted countercurrently with the low-temperature absorption oil. After absorption, the dry gas with rich absorption oil and the dry gas after removal of organic sulfur are obtained. The first-stage amine liquid absorption tower uses amine liquid to absorb and remove hydrogen sulfide from the dry gas after the removal of organic sulfur. After the absorption is completed, rich amine liquid and first-stage absorption tail gas are obtained. A hydrolysis reactor is used to hydrolyze carbonyl sulfur in the primary absorption tail gas to obtain hydrolyzed tail gas; a hydrolysis catalyst bed is set inside the hydrolysis reactor. The secondary amine liquid absorption tower uses lean amine liquid to absorb and remove hydrogen sulfide from the hydrolysis tail gas. After the hydrolysis tail gas is absorbed in the secondary amine liquid absorption tower, purified dry gas is obtained.

2. The dry gas desulfurization system for gas holders according to claim 1, characterized in that, The total sulfur content of the dry gas in the feed gas holder is 100 mg / m³. 3 The above contains carbonyl sulfide at a content of 30 mg / m³. 3 above.

3. The dry gas desulfurization system for gas holders according to claim 1, characterized in that, The low-temperature absorption tower includes a dry gas inlet at the bottom, a rich absorbent oil outlet at the bottom, a lean absorbent oil inlet at the top, and a dry gas outlet for removing organic sulfur at the top.

4. The dry gas desulfurization system for gas holders according to claim 1, characterized in that, The desulfurization system also includes a dry gas heat exchanger, which is used for heat exchange between the dry gas in the feed gas holder and the rich absorption oil; the cold material inlet of the dry gas heat exchanger is connected to the cold material outlet of the absorption oil heat exchanger, and the cold material outlet of the dry gas heat exchanger is connected to the rich absorption oil pipeline.

5. The dry gas desulfurization system for gas holders according to claim 1, characterized in that, The desulfurization system also includes an absorbent oil heat exchanger and a cooler; the absorbent oil heat exchanger is used for heat exchange between rich absorbent oil and lean absorbent oil, and the cooler is used to further cool the lean absorbent oil after it has been cooled down.

6. The dry gas desulfurization system for gas holders according to claim 1, characterized in that, The desulfurization system also includes an absorption tail gas heat exchanger and a heater. The absorption tail gas heat exchanger is used for heat exchange between the primary absorption tail gas from the primary amine liquid absorption tower and the hydrolysis tail gas. The heater is used to heat the primary absorption tail gas after it has been preheated by the absorption tail gas heat exchanger.

7. The dry gas desulfurization system for gas holders according to claim 6, characterized in that, The heater is heated by steam.

8. The dry gas desulfurization system for gas holders according to claim 1, characterized in that, The hydrolysis reactor includes an absorption tail gas inlet at the bottom and a hydrolysis tail gas outlet at the top. The hydrolysis tail gas outlet at the top of the hydrolysis reactor is connected to the hot material inlet of the absorption tail gas heat exchanger via a pipeline, and the absorption tail gas inlet at the bottom of the hydrolysis reactor is connected to the heater outlet via a pipeline; the absorption tail gas inlet is also connected to a steam pipeline to supplement the steam required for the hydrolysis reaction.

9. The dry gas desulfurization system for gas holders according to claim 1, characterized in that, The hydrolysis catalyst bed in the hydrolysis reactor is a fixed bed.

10. The dry gas desulfurization system for gas holders according to claim 1, characterized in that, The low-temperature absorption tower is a packed tower; and / or, The primary amine absorption tower and the secondary amine absorption tower are packed towers or plate towers.

11. The dry gas desulfurization system for gas holders according to claim 1, characterized in that, The primary amine absorption tower includes a lower inlet for removing organic sulfur dry gas, a bottom outlet for rich amine liquid, an upper inlet for lean amine liquid, and a top outlet for primary absorption tail gas. The secondary amine absorption tower includes a hydrolysis tail gas inlet at the bottom, an amine liquid outlet at the bottom, a lean amine liquid inlet at the top, and a purified dry gas outlet at the top.

12. The dry gas desulfurization system for gas holders according to claim 11, characterized in that, The inlet of the primary amine absorption tower for removing organic sulfur dry gas is connected to the outlet of the low-temperature absorption tower for removing organic sulfur dry gas. The hydrolysis tail gas inlet of the secondary amine absorption tower is connected to the hot material outlet of the absorption tail gas heat exchanger via a pipeline. The amine outlet is connected to the amine inlet of the primary amine absorption tower via a pipeline and an amine pump. The lean amine inlet is connected to the lean amine pipeline, and the purified dry gas outlet is connected to the purified dry gas pipeline.

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