System and method for removing hydrogen sulfide and carbonyl sulfide in natural gas

Abstract

The invention belongs to the technical field of natural gas purification treatment, and discloses a system and method for removing hydrogen sulfide and carbonyl sulfide in natural gas, and the system comprises a carbonyl sulfide removal subsystem and a hydrogen sulfide removal subsystem; the carbonyl sulfide removal subsystem is used for carrying out hydrolysis removal on carbonyl sulfide in the natural gas to be purified under the action of a carbonyl sulfide hydrolysis catalyst to obtain natural gas without carbonyl sulfide; the hydrogen sulfide removal subsystem is used for removing hydrogen sulfide in the natural gas subjected to carbonyl sulfide removal to obtain purified natural gas; the carbonyl sulfide removal subsystem is used for converting carbonyl sulfide in natural gas into hydrogen sulfide, organic sulfur carbonyl sulfide can be effectively converted into hydrogen sulfide, and the conversion rate can reach 99% or above; and hydrogen sulfide is converted into elemental sulfur through the hydrogen sulfide removal subsystem by utilizing a complex iron desulfurization process, so that the hydrogen sulfide in the natural gas is removed.

Description

Technical Field

[0001] The invention belongs to the technical field of natural gas purification and processing, and particularly relates to a system and method for removing hydrogen sulfide and carbonyl sulfide from natural gas. Background Art

[0002] Natural gas refers to a mixture of hydrocarbon and non-hydrocarbon gases naturally stored in the strata, with methane as its main component. As a clean and efficient primary energy source, natural gas has significant benefits in protecting the environment and reducing the greenhouse effect. However, most natural gases contain a certain concentration of sulfur-containing gas, which can easily lead to corrosion of equipment and pipelines during the extraction, transportation and processing of natural gas, and there are serious gas safety and environmental problems when it is used. Among them, sulfur-containing gases include inorganic sulfur and organic sulfur, such as hydrogen sulfide and carbonyl sulfide. At the same time, using sulfur-containing natural gas as a chemical raw material often poisons and inactivates the catalyst in the chemical reaction process. Therefore, natural gas must be desulfurized.

[0003] At present, the existing natural gas desulfurization methods mainly include physical and chemical absorption methods. Although they can remove inorganic sulfur and carbon dioxide from natural gas together, they have problems such as low sulfur capacity, inability to remove organic sulfur, and easy generation of hazardous waste liquids. Summary of the invention

[0004] In view of the technical problems existing in the prior art, the present invention provides a method and system for removing hydrogen sulfide and carbonyl sulfide in natural gas, so as to solve the technical problems that the existing natural gas desulfurization method has low sulfur capacity, cannot remove organic sulfur and easily produces hazardous waste liquid.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: The present invention provides a system for removing hydrogen sulfide and carbonyl sulfide from natural gas, comprising a carbonyl sulfide removal subsystem and a hydrogen sulfide removal subsystem; the carbonyl sulfide removal subsystem is used to hydrolyze and remove carbonyl sulfide in the natural gas to be purified under the action of a carbonyl sulfide hydrolysis catalyst to obtain natural gas from which carbonyl sulfide has been removed; the hydrogen sulfide removal subsystem is used to remove hydrogen sulfide from the natural gas from which carbonyl sulfide has been removed to obtain purified natural gas; The hydrogen sulfide removal subsystem includes an absorption tower, a sulfur filter, a regeneration tower and an air pump; The air inlet of the absorption tower is connected to the outlet of the carbonyl sulfide removal subsystem, and the rich liquid outlet of the absorption tower is connected to the liquid inlet of the sulfur filter; the liquid outlet of the sulfur filter is connected to the liquid inlet of the regeneration tower, and the liquid outlet of the regeneration tower is connected to the liquid return port of the absorption tower; the outlet of the air pump is connected to the air inlet of the regeneration tower; the air outlet of the absorption tower is used to be connected to a natural gas storage device.

[0006] Furthermore, the filler of the absorption tower is a complex iron liquid; wherein the complex iron liquid is one or more of EDTA ferroamine, EDTA-Na3, EDTA sodium iron, EDTA tetrasodium, sorbitol, and citric acid.

[0007] Furthermore, the hydrogen sulfide removal subsystem also includes a liquid circulation pump; the liquid circulation pump is arranged inside the regeneration tower, and the outlet of the liquid circulation pump is connected to the liquid outlet of the regeneration tower.

[0008] Further, the carbonyl sulfide removal subsystem includes a steam furnace and a hydrolysis reactor; The first inlet of the steam furnace is used to be connected to a natural gas source to be purified, the second inlet of the steam furnace is used to be connected to a preset water source, the first outlet and the second outlet of the steam furnace are both connected to the inlet of the hydrolysis reactor, and the outlet of the hydrolysis reactor is connected to the air inlet of the absorption tower; wherein the hydrolysis reactor is pre-filled with a carbonyl sulfide hydrolysis catalyst.

[0009] Furthermore, a first sampling port is provided on the pipeline between the hydrolysis reactor and the absorption tower; wherein the first sampling port is used to sample the natural gas from which carbonyl sulfide has been removed, and to detect the content of carbonyl sulfide in the sampled natural gas.

[0010] Furthermore, the carbonyl sulfide hydrolysis catalyst is prepared using a carrier, an active ingredient precursor and an additive precursor as raw materials, the carrier is a composite of nano-titanium dioxide and silicon dioxide aerogel, the active ingredient precursor is an alkali metal compound, and the additive precursor is a transition metal compound.

[0011] Furthermore, it also includes a drying bottle, which is arranged between the gas outlet of the absorption tower and the natural gas storage device; wherein the inlet of the drying bottle is connected to the gas outlet of the absorption tower, and the outlet of the drying bottle is connected to the inlet of the natural gas storage device; a second sampling port is also arranged at the outlet of the drying bottle; wherein the second sampling port is used to sample the outlet gas of the absorption tower and detect the content of hydrogen sulfide in the sampled outlet gas.

[0012] Furthermore, the operating temperature of the absorption tower is 40-60°C.

[0013] The present invention also provides a method for removing hydrogen sulfide and carbonyl sulfide from natural gas, and utilizes the system for removing hydrogen sulfide and carbonyl sulfide from natural gas.

[0014] The method for removing hydrogen sulfide and carbonyl sulfide from natural gas comprises: The natural gas to be purified is introduced into a carbonyl sulfide removal subsystem, so as to hydrolyze and remove carbonyl sulfide in the natural gas to be purified by using a carbonyl sulfide hydrolysis catalyst to obtain natural gas from which carbonyl sulfide has been removed; The natural gas from which carbonyl sulfide has been removed is introduced into a hydrogen sulfide removal subsystem to react and absorb hydrogen sulfide in the natural gas from which carbonyl sulfide has been removed, thereby obtaining purified natural gas.

[0015] Furthermore, the natural gas from which carbonyl sulfide has been removed is introduced into a hydrogen sulfide removal subsystem to react and absorb hydrogen sulfide in the natural gas from which carbonyl sulfide has been removed to obtain a purified natural gas, which is specifically as follows: The natural gas from which carbonyl sulfide has been removed is introduced into the absorption tower, where it reacts with the filler in the absorption tower to generate sulfur, thereby removing hydrogen sulfide. The filler after reacting with hydrogen sulfide enters the sulfur filter from the rich liquid outlet of the absorption tower, and the sulfur element in the filler after reacting with hydrogen sulfide is filtered; The filtered filler enters the regeneration tower to react with the air to form regenerated filler; the regenerated filler re-enters the absorption tower for recycling.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a system and method for removing hydrogen sulfide and carbonyl sulfide from natural gas. The carbonyl sulfide removal subsystem is used to convert carbonyl sulfide in natural gas into hydrogen sulfide, and organic sulfur carbonyl sulfide can be effectively converted into hydrogen sulfide, and the conversion rate can reach 99% or more; the hydrogen sulfide removal subsystem uses a complex iron desulfurization process to convert hydrogen sulfide into sulfur element, thereby realizing the removal of hydrogen sulfide from natural gas; the process of the present invention is simple, has large sulfur absorption capacity, high desulfurization efficiency, easy sulfur recovery, no pollution to the environment by the desulfurizer, no waste liquid generation, the desulfurizer can be regenerated, and the regeneration cost is low, the process is simple, and the like; wherein, H 2 S can reach 1mg / m 3 Below, the carbonyl sulfide removal rate can reach 99% or above. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural block diagram of the system for removing hydrogen sulfide and carbonyl sulfide from natural gas provided in Example 1.

[0018] Among them, 1 is a gas storage cylinder, 2 is a gas flow controller, 3 is a steam furnace, 4 is a water storage bottle, 5 is a liquid pump, 6 is a hydrolysis reactor, 7 is a heating furnace, 8 is a first sampling port; 9 is an absorption tower, 10 is a first liquid flow regulating valve, 11 is a sulfur filter, 12 is a regeneration tower, 13 is a liquid circulation pump, 14 is a second liquid flow regulating valve, 15 is a liquid flow meter, 16 is an air pump, 17 is a gas flow meter, 18 is a drying bottle, and 19 is a second sampling port. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail in the following specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0020] Example 1 As attached Figure 1 As shown, this embodiment 1 provides a system for removing hydrogen sulfide and carbonyl sulfide in natural gas, including a carbonyl sulfide removal subsystem and a hydrogen sulfide removal subsystem.

[0021] The carbonyl sulfide removal subsystem is used to hydrolyze and remove carbonyl sulfide in the natural gas to be purified under the action of a carbonyl sulfide hydrolysis catalyst to obtain natural gas from which carbonyl sulfide has been removed; the hydrogen sulfide removal subsystem is used to remove hydrogen sulfide in the natural gas from which carbonyl sulfide has been removed to obtain purified natural gas.

[0022] The carbonyl sulfide removal subsystem comprises a gas storage bottle 1, a gas flow controller 2, a steam furnace 3, a water storage bottle 4, a liquid pump 5, a hydrolysis reactor 6 and a heating furnace 7.

[0023] The gas cylinder 1 stores natural gas to be purified as a source of natural gas to be purified; the outlet of the gas cylinder 1 is connected to the inlet of the gas flow controller 2, and the outlet of the gas flow controller 2 is connected to the first inlet of the steam furnace 3; wherein the gas flow controller 2 is used to control the flow of the natural gas to be purified entering the steam furnace 3; the water storage bottle 4 stores water as a preset water source; the outlet of the water storage bottle 4 is connected to the inlet of the liquid pump 5, and the outlet of the liquid pump 5 is connected to the second inlet of the steam furnace 3; wherein the liquid pump 5 is used to pump the water stored in the water storage bottle 4 into the steam furnace 3; the first outlet and the second outlet of the steam furnace 3 are both connected to the inlet of the hydrolysis reactor 6.

[0024] It should be noted that the steam furnace 3 is used to heat the natural gas to be purified to a preset temperature, and is also used to heat water into water vapor, and can transport the heated natural gas to be purified and water vapor to the hydrolysis reactor 6; specifically, the steam furnace 3 includes two heating chambers, and the two heating chambers are used to heat the natural gas to be purified and water, respectively; wherein, the inlet of the first heating chamber is connected to the outlet of the gas flow controller 2, and the outlet of the first heating chamber is connected to the inlet of the hydrolysis reactor 6; the inlet of the second heating chamber is connected to the outlet of the liquid pump 5, and the outlet of the second heating chamber is connected to the inlet of the hydrolysis reactor 6.

[0025] The outlet of the hydrolysis reactor 6 is connected to the inlet of the hydrogen sulfide removal subsystem, and the hydrolysis reactor 6 is pre-filled with a carbonyl sulfide hydrolysis catalyst; wherein the carbonyl sulfide hydrolysis catalyst is prepared using a carrier, an active ingredient precursor and an additive precursor as raw materials, the carrier is a composite of nano-titanium dioxide and silicon dioxide aerogel, the active ingredient precursor is an alkali metal compound, and the additive precursor is a transition metal compound; the heating furnace 7 is arranged outside the hydrolysis reactor 6, and is used to heat the hydrolysis reactor 6.

[0026] It should be noted that the preparation process of the carbonyl sulfide hydrolysis catalyst is as follows: Prepare a composite of nano titanium dioxide and silicon dioxide aerogel as a carrier; prepare a solution of an active ingredient precursor as an impregnation liquid 1; prepare a solution of an additive precursor as an impregnation liquid 2; preferably, the active ingredient precursor is sodium carbonate, potassium carbonate and potassium hydroxide, and the additive precursor is nickel nitrate. The carrier is impregnated in the impregnation liquid 1, and then the solid-liquid separation is performed, and the obtained solid is dried and calcined to obtain a solid phase to be used. The solid phase to be used is impregnated in the impregnation liquid 2, and then the solid-liquid separation is performed, and the obtained solid is dried and calcined to obtain the carbonyl sulfide hydrolysis catalyst.

[0027] The hydrogen sulfide removal subsystem includes an absorption tower 9, a first liquid flow regulating valve 10, a sulfur filter 11, a regeneration tower 12, a liquid circulation pump 13, a second liquid flow regulating valve 14, a liquid flow meter 15, an air pump 16, a gas flow meter 17 and a drying bottle 18.

[0028] The air inlet of the absorption tower 9 is connected to the outlet of the hydrolysis reactor 6, and the rich liquid outlet of the absorption tower 9 is connected to the inlet of the first liquid flow regulating valve 10; the air outlet of the absorption tower 9 is used to be connected to a natural gas storage device, and the natural gas storage device is used to store purified natural gas; the outlet of the first liquid flow regulating valve 10 is connected to the liquid inlet of the sulfur filter 11, and the liquid outlet of the sulfur filter 11 is connected to the liquid inlet of the regeneration tower 12.

[0029] The liquid circulation pump 13 is arranged inside the regeneration tower 12, and is used to pump the liquid in the regeneration tower 12 into the absorption tower 9 through the liquid outlet of the regeneration tower 12; specifically, the inlet of the liquid circulation pump 13 is connected to the inner cavity of the regeneration tower 12, and the outlet of the liquid circulation pump 13 is connected to one end of the liquid outlet of the regeneration tower 12; the other end of the liquid outlet of the regeneration tower 12 is connected to the inlet of the second liquid flow regulating valve 14, the outlet of the second liquid flow regulating valve 14 is connected to the inlet of the liquid flow meter 15, and the outlet of the liquid flow meter 15 is connected to the liquid return port of the absorption tower 9.

[0030] The inlet of the air pump 16 is connected to the outside atmosphere, the outlet of the air pump 16 is connected to the inlet of the gas flow meter 17, and the outlet of the gas flow meter 17 is connected to the air inlet of the regeneration tower 12; wherein, the air pump 16 is used to blow fresh air into the regeneration tower 12.

[0031] The drying bottle 18 is arranged between the gas outlet of the absorption tower 9 and the natural gas storage device, and the drying bottle 18 is used to dry the outlet gas of the absorption tower 9; wherein the inlet of the drying bottle 18 is connected to the gas outlet of the absorption tower 9, and the outlet of the drying bottle 18 is connected to the inlet of the natural gas storage device.

[0032] It should be noted that a first sampling port 18 is provided on the pipeline between the hydrolysis reactor 6 and the absorption tower 9; wherein the first sampling port 18 is used to sample the natural gas from which carbonyl sulfide has been removed, and to detect the content of carbonyl sulfide in the sampled natural gas; preferably, a gas chromatography test method is used to detect the content of carbonyl sulfide in the sampled natural gas; a second sampling port 19 is also provided at the outlet of the drying bottle 18; the second sampling port 19 is used to sample the outlet gas of the absorption tower 9, and to detect the content of hydrogen sulfide in the sampled outlet gas; preferably, a gas chromatography test method is used to detect the content of hydrogen sulfide in the sampled outlet gas.

[0033] The system for removing hydrogen sulfide and carbonyl sulfide from natural gas described in Example 1 is used as follows: (1) Carbonyl sulfide removal subsystem; The natural gas to be purified is heated to 70°C by a steam furnace 3 and heated at a space velocity of 1000-3000 h -1 , passes through the hydrolysis reactor 6 from top to bottom at a pressure of 0.1-0.2MPa; wherein the hydrolysis reactor 6 is equipped with a carbonyl sulfide hydrolysis catalyst; the sampling liquid pump 5 pumps the water to the steam furnace 3, where it is heated into water vapor and enters the hydrolysis reactor 6 together with the heated natural gas to be purified; in the hydrolysis reactor 6, the carbonyl sulfide in the natural gas to be purified is converted into hydrogen sulfide under the action of the carbonyl sulfide hydrolysis catalyst, so that the carbonyl sulfide can be removed.

[0034] The carbonyl sulfide in the natural gas to be purified is converted into hydrogen sulfide under the action of the carbonyl sulfide hydrolysis catalyst, so that the carbonyl sulfide can be removed. Specifically, the carbonyl sulfide is converted into H2S under the catalytic action of the carbonyl sulfide hydrolysis catalyst. 2 S and CO 2 ; The conversion process is as follows: .

[0035] (2) Hydrogen sulfide removal subsystem: The natural gas from which carbonyl sulfide has been removed is introduced into an absorption tower 9 filled with a complex iron liquid; in the absorption tower 9, the complex iron liquid reacts chemically with hydrogen sulfide in the natural gas to generate sulfur element, thereby completing the removal of hydrogen sulfide; the generated sulfur element and the filler after reacting with hydrogen sulfide flow out from the rich liquid outlet of the absorption tower 9 and enter the sulfur filter 11, after the sulfur element is filtered by the sulfur filter 11, the filler after reacting with hydrogen sulfide enters the regeneration tower 12; at the same time, fresh air is blown into the regeneration tower 12 through the air pump 16 to regenerate the filler after reacting with hydrogen sulfide, and the regenerated filler is pumped into the absorption tower 9 through the liquid pump 13, the regeneration is completed, and the cycle is continued.

[0036] The process of chemically reacting the complex iron liquid with hydrogen sulfide in natural gas to generate sulfur is as follows: using the complex iron method, H 2 S is converted into elemental sulfur and removed; the process of generating elemental sulfur is as follows: .

[0037] The process of regenerating the filler after the reaction with hydrogen sulfide is as follows: using oxygen in the air to 2+ Oxidized to Fe 3+ The complex is recycled, and its chemical reaction formula is: .

[0038] It should be noted that the natural gas from which carbonyl sulfide has been removed is introduced into a hydrogen sulfide removal subsystem to react and absorb the hydrogen sulfide in the natural gas from which carbonyl sulfide has been removed. In the process of obtaining the purified natural gas, the hydrogen sulfide in the natural gas from which carbonyl sulfide has been removed is converted into elemental sulfur under the catalytic oxidation of the trivalent iron ions in the complex iron liquid, and the trivalent iron ions are reduced to divalent iron ions at this time; the filtered filler enters the regeneration tower 12 to react with the air, and the divalent iron ions are reoxidized to trivalent iron ions by the oxygen in the air, thereby realizing the regeneration and recycling of the filler in the absorption tower 9.

[0039] In this embodiment 1, the carbonyl sulfide removal subsystem is used to convert carbonyl sulfide in natural gas into hydrogen sulfide, which can effectively convert organic sulfur carbonyl sulfide into hydrogen sulfide; the hydrogen sulfide removal subsystem uses the complex iron desulfurization process to convert hydrogen sulfide into elemental sulfur, thereby realizing the removal of hydrogen sulfide in natural gas, which has the characteristics of large sulfur absorption capacity, high desulfurization efficiency, easy sulfur recovery, no pollution to the environment by the desulfurizer, no waste liquid generation, regeneration of the desulfurizer, low regeneration cost, simple process, etc.

[0040] Example 2 This embodiment 2 provides a method for removing hydrogen sulfide and carbonyl sulfide from natural gas, using the removal system provided in the above embodiment 1 to simulate the composition of natural gas in a natural gas field, prepare raw gas and use it as natural gas to be purified; wherein the composition of the natural gas to be purified, by volume fraction, is as follows: 1.22% H 2 S, 600mg / m 3 COS, 30% CH 4 , 7.00% CO 2 and the balance nitrogen.

[0041] Specifically, the method for removing hydrogen sulfide and carbonyl sulfide from natural gas comprises the following steps: Step 1: Add the pre-obtained carbonyl sulfide hydrolysis catalyst into the hydrolysis reactor 6; then, pass the natural gas to be purified into the steam furnace 3 and heat it to 70°C at a space velocity of 3000h / min. -1 , passing through the hydrolysis reactor 6 from top to bottom at a pressure of 0.1 MPa; at the same time, water is transported to the steam furnace 3 by a liquid pump 5, heated into water vapor in the steam furnace 3, and the water vapor and natural gas enter the hydrolysis reactor 6 together; in the hydrolysis reactor 6, the carbonyl sulfide in the natural gas to be purified is converted into hydrogen sulfide under the action of the hydrolysis catalyst, so that the carbonyl sulfide can be removed; at a space velocity of 3000h -1 The sampling gas flow rate at the first sampling port 18 is calculated to be 200 mL / min, and then the concentration of carbonyl sulfide at the first sampling port 18 is detected by gas chromatography.

[0042] Step 2, 500mL of complex iron liquid is prepared by using EDTA iron amine and EDTA-Na3, and the complex iron liquid is filled into the absorption tower 9; then, the natural gas from which carbonyl sulfide is removed is passed into the absorption tower 9; in the absorption tower 9, the complex iron liquid and the hydrogen sulfide in the natural gas from which carbonyl sulfide is removed chemically react to generate sulfur element, and the removal of hydrogen sulfide is completed; the generated sulfur element and the filler after reacting with hydrogen sulfide flow out from the rich liquid outlet of the absorption tower 9 and enter the sulfur filter 11, after the sulfur element is filtered by the sulfur filter 11, the filler after reacting with hydrogen sulfide enters the regeneration tower 12; at the same time, fresh air is blown into the regeneration tower 12 by the air pump 16; wherein, the flow rate of the fresh air is 2L / min; the filler after reacting with hydrogen sulfide is regenerated, and the regenerated filler is pumped into the absorption tower 9 by the liquid pump 13, the regeneration is completed, and the circulation is continued; wherein, the control circulation amount is 25mL / min; the hydrogen sulfide concentration is tested by gas chromatography at the second sampling port 19.

[0043] Example 3 This embodiment 3 provides a method for removing hydrogen sulfide and carbonyl sulfide from natural gas, using the removal system provided in the above embodiment 1 to simulate the composition of natural gas in a natural gas field, prepare raw gas and use it as natural gas to be purified; wherein the composition of the natural gas to be purified, by volume fraction, is as follows: 1.22% H 2 S, 600mg / m 3 COS, 30% CH 4 , 7.00% CO 2 and the balance nitrogen.

[0044] Specifically, the method for removing hydrogen sulfide and carbonyl sulfide from natural gas comprises the following steps: Step 1: Add the pre-obtained carbonyl sulfide hydrolysis catalyst into the hydrolysis reactor 6; then, pass the natural gas to be purified into the steam furnace 3 and heat it to 70°C at a space velocity of 2000h / min. -1 , passing through the hydrolysis reactor 6 from top to bottom at a pressure of 0.1 MPa; at the same time, the water is transported to the steam furnace 3 by the liquid pump 5, heated into water vapor in the steam furnace 3, and the water vapor and natural gas enter the hydrolysis reactor 6 together; in the hydrolysis reactor 6, the carbonyl sulfide in the natural gas to be purified is converted into hydrogen sulfide under the action of the hydrolysis catalyst, so that the carbonyl sulfide can be removed; at a space velocity of 2000h -1 The sampling gas flow rate at the first sampling port 18 is calculated to be 133 mL / min, and then the concentration of carbonyl sulfide at the first sampling port 18 is detected by gas chromatography.

[0045] Step 2, 400mL of complex iron liquid is prepared by using EDTA iron amine and EDTA-Na3, and the complex iron liquid is filled into the absorption tower 9; then, the natural gas from which carbonyl sulfide is removed is passed into the absorption tower 9; in the absorption tower 9, the complex iron liquid and the hydrogen sulfide in the natural gas from which carbonyl sulfide is removed chemically react to generate sulfur element, and the removal of hydrogen sulfide is completed; the generated sulfur element and the filler after reacting with hydrogen sulfide flow out from the rich liquid outlet of the absorption tower 9 and enter the sulfur filter 11, after the sulfur element is filtered by the sulfur filter 11, the filler after reacting with hydrogen sulfide enters the regeneration tower 12; at the same time, fresh air is blown into the regeneration tower 12 by the air pump 16; wherein, the flow rate of the fresh air is 2L / min; the filler after reacting with hydrogen sulfide is regenerated, and the regenerated filler is pumped into the absorption tower 9 by the liquid pump 13, the regeneration is completed, and the circulation is continued; wherein, the control circulation amount is 25mL / min; the hydrogen sulfide concentration is tested by gas chromatography at the second sampling port 19.

[0046] The test results of the above embodiments 2-3 are shown in Table 1 below: Table 1 COS hydrolysis conversion rate (%) and outlet hydrogen sulfide concentration (mg / m 3 )

[0047] It can be seen from Table 1 above that the H 2 S can reach 1mg / m 3 Below, the carbonyl sulfide removal rate can reach 99% or above.

[0048] In the system and method for removing hydrogen sulfide and carbonyl sulfide from natural gas of the present invention, carbonyl sulfide in the natural gas to be purified is converted into H 2 S and CO 2 , H 2 S is then subjected to the complex iron method to directly convert H 2 S is converted into elemental sulfur and removed; the complex iron liquid in the complex iron method uses oxygen in the air to convert Fe 2+ Oxidized to Fe 3+ complex and recycled.

[0049] In the present invention, the carbonyl sulfide hydrolysis catalyst used can be hydrolyzed at low temperature, has low energy consumption and long service life, can efficiently hydrolyze carbonyl sulfide into hydrogen sulfide, and does not generate hazardous waste; in the process of removing hydrogen sulfide by the complex iron method, a complex iron liquid is used as a desulfurizing agent, the complex iron liquid is prepared by non-toxic and harmless chemicals, is harmless to the human body, and has no corrosive effect on facilities; secondly, the complex iron liquid has a high sulfur capacity and a high desulfurization efficiency; the sulfur generated in the desulfurization process has a high purity and can generate certain economic benefits; the desulfurizing agent can be regenerated by blowing in air, the regeneration cost is low, and it is environmentally friendly and does not generate hazardous waste.

[0050] The above embodiment is only one of the implementation methods that can realize the technical solution of the present invention. The scope of protection claimed by the present invention is not limited only to this embodiment, but also includes changes, replacements and other implementation methods that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention.

Claims

1. A system for removing hydrogen sulfide and carbonyl sulfide from natural gas, characterized in that: It comprises a carbonyl sulfide removal subsystem and a hydrogen sulfide removal subsystem; the carbonyl sulfide removal subsystem is used to hydrolyze and remove carbonyl sulfide in the natural gas to be purified under the action of a carbonyl sulfide hydrolysis catalyst to obtain natural gas from which carbonyl sulfide has been removed; The hydrogen sulfide removal subsystem is used to remove hydrogen sulfide from the natural gas from which carbonyl sulfide has been removed to obtain purified natural gas; The hydrogen sulfide removal subsystem comprises an absorption tower (9), a sulfur filter (11), a regeneration tower (12) and an air pump (16); The air inlet of the absorption tower (9) is connected to the outlet of the carbonyl sulfide removal subsystem, and the rich liquid outlet of the absorption tower (9) is connected to the liquid inlet of the sulfur filter (11); the liquid outlet of the sulfur filter (11) is connected to the liquid inlet of the regeneration tower (12), and the liquid outlet of the regeneration tower (12) is connected to the liquid return port of the absorption tower (9); the outlet of the air pump (16) is connected to the air inlet of the regeneration tower (12); and the air outlet of the absorption tower (9) is used to be connected to a natural gas storage device.

2. A system for removing hydrogen sulfide and carbonyl sulfide from natural gas according to claim 1, characterized in that: The filler of the absorption tower (9) is a complex iron liquid; wherein the complex iron liquid is one or more of EDTA iron amine, EDTA-Na3, EDTA iron sodium, EDTA tetrasodium, sorbitol, and citric acid.

3. A system for removing hydrogen sulfide and carbonyl sulfide from natural gas according to claim 1, characterized in that: The hydrogen sulfide removal subsystem further comprises a liquid circulation pump (13); the liquid circulation pump (13) is arranged inside the regeneration tower (12), and the outlet of the liquid circulation pump (13) is connected to the liquid outlet of the regeneration tower (12).

4. A system for removing hydrogen sulfide and carbonyl sulfide from natural gas according to claim 1, characterized in that: The carbonyl sulfide removal subsystem comprises a steam furnace (3) and a hydrolysis reactor (6); The first inlet of the steam furnace (3) is used to be connected to a natural gas source to be purified, the second inlet of the steam furnace (3) is used to be connected to a preset water source, the first outlet and the second outlet of the steam furnace (3) are both connected to the inlet of the hydrolysis reactor (6), and the outlet of the hydrolysis reactor (6) is connected to the air inlet of the absorption tower (9); wherein the hydrolysis reactor (6) is pre-filled with a carbonyl sulfide hydrolysis catalyst.

5. A system for removing hydrogen sulfide and carbonyl sulfide from natural gas according to claim 4, characterized in that: A first sampling port (8) is provided on the pipeline between the hydrolysis reactor (6) and the absorption tower (9); wherein the first sampling port (8) is used to sample the natural gas from which carbonyl sulfide has been removed, and to detect the content of carbonyl sulfide in the sampled natural gas.

6. A system for removing hydrogen sulfide and carbonyl sulfide from natural gas according to claim 4, characterized in that: The carbonyl sulfide hydrolysis catalyst is prepared using a carrier, an active ingredient precursor and an additive precursor as raw materials. The carrier is a composite of nano titanium dioxide and silicon dioxide aerogel, the active ingredient precursor is an alkali metal compound, and the additive precursor is a transition metal compound.

7. A system for removing hydrogen sulfide and carbonyl sulfide from natural gas according to claim 1, characterized in that: The invention also comprises a drying bottle (18), wherein the drying bottle (18) is arranged between the gas outlet of the absorption tower (9) and the natural gas storage device; wherein the inlet of the drying bottle (18) is connected to the gas outlet of the absorption tower (9), and the outlet of the drying bottle (18) is connected to the inlet of the natural gas storage device; and a second sampling port (19) is also arranged at the outlet of the drying bottle (18); wherein the second sampling port (19) is used to sample the gas outlet of the absorption tower (9) and detect the content of hydrogen sulfide in the sampled gas outlet.

8. A system for removing hydrogen sulfide and carbonyl sulfide from natural gas according to claim 1, characterized in that: The operating temperature of the absorption tower (9) is 40-60°C.

9. A method for removing hydrogen sulfide and carbonyl sulfide from natural gas, characterized in that: A system for removing hydrogen sulfide and carbonyl sulfide from natural gas as described in any one of claims 1 to 8. The method for removing hydrogen sulfide and carbonyl sulfide from natural gas comprises: The natural gas to be purified is introduced into a carbonyl sulfide removal subsystem, so as to hydrolyze and remove carbonyl sulfide in the natural gas to be purified by using a carbonyl sulfide hydrolysis catalyst to obtain natural gas from which carbonyl sulfide has been removed; The natural gas from which carbonyl sulfide has been removed is introduced into a hydrogen sulfide removal subsystem to react and absorb hydrogen sulfide in the natural gas from which carbonyl sulfide has been removed, thereby obtaining purified natural gas.

10. The method for removing hydrogen sulfide and carbonyl sulfide from natural gas according to claim 9, characterized in that: The natural gas from which carbonyl sulfide has been removed is introduced into a hydrogen sulfide removal subsystem to react and absorb hydrogen sulfide in the natural gas from which carbonyl sulfide has been removed to obtain a purified natural gas, which is specifically as follows: The natural gas from which carbonyl sulfide has been removed is introduced into an absorption tower (9), where it reacts with the filler in the absorption tower (9) to generate sulfur, thereby removing hydrogen sulfide; The filler after the reaction with hydrogen sulfide enters the sulfur filter (11) from the rich liquid outlet of the absorption tower (9), and the sulfur element in the filler after the reaction with hydrogen sulfide is filtered; The filtered filler enters the regeneration tower (12) to react with air to form regenerated filler; the regenerated filler re-enters the absorption tower (9) for recycling.

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