A desulfurizer for absorbing hydrogen sulfide and organic sulfur under normal pressure and a preparation method and application thereof

Abstract

The present application provides a desulfurizer for absorbing hydrogen sulfide and organic sulfur under normal pressure, and a preparation method and application thereof. The desulfurizer comprises 20-35% of steric hindrance amine, 5-20% of organic sulfur absorption promoter, 5-20% of auxiliary agent, and the balance of water. The organic sulfur absorption promoter comprises piperazinyl carboxylic acid compound, and the auxiliary agent comprises amide compound. The preparation method comprises adding the steric hindrance amine, the organic sulfur absorption promoter and the auxiliary agent into water according to the mass percentage of each component, and stirring to obtain the desulfurizer. The desulfurizer has high removal rate of hydrogen sulfide under normal pressure, and can effectively remove organic sulfur, while not removing carbon dioxide completely, so as to reduce the acid gas load in the desulfurizer, thereby ensuring the removal of hydrogen sulfide and organic sulfur under the condition of low circulation amount. Therefore, the desulfurizer is suitable for desulfurizing hydrogenation tail gas of a purification plant and a refinery, and effectively reduces the emission of tail gas sulfur dioxide.

Description

Technical Field

[0001] This invention relates to a desulfurizing agent that absorbs hydrogen sulfide and organic sulfur under normal pressure, its preparation method and application, belonging to the field of desulfurization technology. Background Technology

[0002] In natural gas purification units using the amine process, the main components include desulfurization, dehydration, sulfur recovery, and tail gas treatment. The tail gas treatment section plays a crucial role in improving sulfur recovery and protecting the environment. Currently, the main tail gas treatment processes include reduction absorption, direct reduction conversion, and oxidation absorption. The reduction absorption tail gas treatment process is the most widely used, and most large-scale natural gas purification plants and refineries' sulfur recovery units are equipped with reduction absorption tail gas treatment units. This process currently primarily uses amine desulfurizing agents to treat the hydrogenated sulfur recovery tail gas.

[0003] Sulfur recovery hydrogenation tail gas contains a certain amount of organic sulfur, typically above 10 ppm, and in some units even exceeding 50 ppm. Because the pressure of sulfur recovery hydrogenation tail gas is very low, close to atmospheric pressure, currently used conventional alcohol amine desulfurizers are ineffective at removing H2S and organic sulfur from the hydrogenation tail gas, with the purified tail gas typically containing around 100 mg / m³. 3 The removal rate of organic sulfur (COS) is typically only 5% to 10%. This not only reduces sulfur recovery but also increases SO2 content in exhaust gases, causing environmental pollution. Therefore, new technologies must be developed to address the poor removal efficiency of conventional amine desulfurizers for H2S and organic sulfur under low pressure, in order to achieve ultra-low SO2 emissions from exhaust gases and protect the environment. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention aims to provide a desulfurizing agent that absorbs hydrogen sulfide and organic sulfur under normal pressure, its preparation method, and its application. The desulfurizing agent of the present invention exhibits a high H2S removal rate under normal pressure and can effectively remove organic sulfur, while not completely removing CO2, thus reducing the acid load in the desulfurizing agent.

[0005] To achieve the above objectives, the first aspect of the present invention provides a desulfurizing agent for absorbing hydrogen sulfide and organic sulfur under normal pressure, wherein the desulfurizing agent comprises the following components by mass percentage: 20-35% sterically hindered amine, 5-20% organic sulfur absorption promoter, 5-20% additives, and water as the balance.

[0006] The organic sulfur absorption promoter includes piperazine carboxylic acid compounds; the auxiliary agent includes amide compounds.

[0007] In the above-mentioned desulfurizing agent, preferably, the sterically hindered amine includes one or a combination of several of 4-tert-butylamino-1-butanol, 5-tert-butylamino-1-pentanol, and 6-tert-butylamino-1-hexanol.

[0008] In the above-mentioned desulfurizing agents, preferably, the organic sulfur absorption promoter includes one or a combination of several of 2-(1,4-dimethylpiperazin-2-yl)acetic acid, (3-oxo-1-piperazin)acetic acid, and (3-oxopiperazin-2-yl)acetic acid.

[0009] In the above-mentioned desulfurizing agent, preferably, the auxiliary agent includes one or a combination of several of N,N-dimethylacetamide, N,N-dimethyl-2,2-dimethoxyacetamide and 2-amino-N-pyridin-3-ylacetamide.

[0010] In the above-mentioned desulfurizing agent, preferably, the water content is 20% or more, based on the total mass of the desulfurizing agent being 100%.

[0011] The desulfurizer of this invention utilizes a combination of three substances: a sterically hindered amine, a piperazine carboxylic acid, and an amide. These three substances work synergistically to promote the absorption of H2S and organic sulfur compounds from acidic gases. However, a higher concentration of any single amine does not necessarily lead to better removal of acidic gases. Excessive amine concentration reduces the degree of solute dissociation in the desulfurizer, decreases its autogenous dissociation constant, and makes amine dissociation more difficult, which is detrimental to the removal of acidic gases.

[0012] The sterically hindered amine used in the desulfurizing agent of this invention is a secondary alcohol amine, and their absorption reaction process for H2S in the raw material gas is as follows:

[0013] R1R2NH (sterically hindered amine) + H2S = R1R2NH2 + +HS - (1-1)

[0014] R1 and R2 are substituent groups (the same below). Although the reaction rates of different alcoholic amines with H2S are different, the reactions between them can all be considered as instantaneous proton reactions. The H2S entering the liquid phase is absorbed by the alcoholic amine instantaneously. Its reaction rate is much faster than the diffusion rate of gaseous H2S. The absorption process is a gas film controlled process.

[0015] The sterically hindered amine used in this invention mainly performs the following CO2 absorption reaction:

[0016] H2O=H + +OH - (1-2)

[0017] CO2 + H2O = HCO3- 3- +H +(1-3)

[0018] CO2 + OH - =HCO 3- (1-4)

[0019] R1R2NH (sterically hindered amine) + H + =R1R2NH 2+ (1-5)

[0020] R1R2NH (sterically hindered amine) + HCO 3- =R1R2NCOO - +H2O (1-6)

[0021] Overall reaction equation:

[0022] 2R1R2NH (sterically hindered amine) + CO2 = R1R2NH 2+ +R1R2NCOO - (1-7)

[0023] The CO2 absorption reaction of sterically hindered amines is relatively complex. Due to the steric hindrance of the groups involved, the =NCOO- groups formed in the reaction of sterically hindered amines with CO2 have poor stability. According to the two-film theory, the reaction in equation (1-7) is controlled by the liquid film, therefore its selective desulfurization performance is better than that of alkanolamines (MDEA).

[0024] The absorption of H2S and CO2 by sterically hindered amines is a reversible reaction. At lower temperatures and higher pressures, the reaction proceeds to the right, while at higher temperatures and lower pressures, the reaction proceeds to the left.

[0025] On the other hand, the desulfurizer of the present invention introduces an organic sulfur absorption promoter with a special structure, which can effectively reduce the activation energy of the reaction between sterically hindered amines and organic sulfur (COS), thereby accelerating the hydrolysis rate of COS and improving the removal rate of COS by the desulfurizer under low pressure. This allows the desulfurizer to maintain excellent H2S removal performance while also having a significant ability to remove COS.

[0026] Furthermore, the desulfurizing agent of this invention also incorporates amide-based additives to improve its performance. Amide compounds are aprotic polar solvents that have a physical dissolving effect on organic sulfur and hydrogen sulfide. The amides selected in this invention also exhibit steric hindrance, working synergistically with the sterically hindered amine of this invention to increase the inhibition of CO2 removal and improve selectivity. Simultaneously, the amide-based additives used in this invention can undergo a tripolecular reaction with COS and the sterically hindered amine used in this invention to generate a complex formed by loosely bonded structures, thus enhancing COS removal. The generated complex exists instantaneously and regenerates upon heating due to bond breakage.

[0027] According to a specific embodiment of the present invention, preferably, the desulfurizing agent is prepared by the following steps: adding the sterically hindered amine, the organic sulfur absorption promoter and the auxiliary agent to water according to the mass percentage of each component, and stirring for a period of time to obtain the desulfurizing agent.

[0028] More preferably, the temperature at which the sterically hindered amine, the organic sulfur absorption promoter, and the auxiliary agent are added to water and stirred is 20-30°C.

[0029] More preferably, the sterically hindered amine, the organic sulfur absorption promoter, and the auxiliary agent are added to the water and stirred for 10-40 minutes.

[0030] More preferably, the stirring speed is 30-50 r / min.

[0031] The second aspect of the present invention provides a method for preparing the above-mentioned desulfurizing agent for absorbing hydrogen sulfide and organic sulfur under normal pressure, which includes the following steps: adding the sterically hindered amine, the organic sulfur absorption promoter and the auxiliary agent to water according to the mass percentage of each component, and stirring for a period of time to obtain the desulfurizing agent.

[0032] In the above preparation method, preferably, the temperature at which the sterically hindered amine, the organic sulfur absorption promoter, and the auxiliary agent are added to water and stirred is 20-30°C.

[0033] In the above preparation method, preferably, the sterically hindered amine, the organic sulfur absorption promoter, and the auxiliary agent are added to water and stirred for 10-40 minutes.

[0034] In the above preparation method, preferably, the stirring speed is 30-50 r / min.

[0035] The third aspect of the present invention provides the application of the above-mentioned desulfurizing agent for absorbing hydrogen sulfide and organic sulfur under normal pressure as a desulfurizing agent for sulfur recovery hydrogenation tail gas in natural gas purification plants and / or oil refineries.

[0036] The desulfurizing agent provided by this invention can be used for the deep and large-scale removal of H2S and organic sulfur from the sulfur recovery and hydrogenation tail gas of natural gas purification plants and oil refineries.

[0037] Compared with existing technologies, the desulfurizing agent provided by this invention can reduce the H2S content in the purified gas to <10 mg / m³ under typical gas quality conditions of sulfur recovery and hydrogenation tail gas in oil refineries. 3 The removal rate of organic sulfur is >55%, achieving excellent technical results of deep removal of H2S and organic sulfur under normal pressure.

[0038] The inventors of this invention conducted research on promoting H2S absorption and enhancing COS hydrolysis, and developed the desulfurizing agent of this invention. The desulfurizer of this invention employs a sterically hindered amine with high steric hindrance effect and a high pKa value. This increases the alkalinity of the desulfurizer, which is beneficial for enhancing its ability to absorb H2S, while also improving its selectivity, reducing the competitive absorption of CO2, and increasing the depth of H2S removal under low pressure. Simultaneously, an organic sulfur absorption promoter with a special structure is introduced, which can effectively reduce the activation energy of the reaction between the sterically hindered amine and COS, thereby accelerating the hydrolysis rate of COS and improving the COS removal rate of the desulfurizer under low pressure. This allows the desulfurizer to maintain excellent H2S removal performance while also exhibiting significant COS removal capabilities. Furthermore, an amide-based additive is introduced, which has a physical dissolving effect on organic sulfur and hydrogen sulfide. The amide selected in this invention has a steric hindrance effect, which synergistically works with the sterically hindered amine to increase the inhibition of CO2, further improving the selectivity of the desulfurizer and enhancing COS removal. Therefore, the desulfurizer provided by this invention is a desulfurizer that absorbs H2S and organic sulfur under normal pressure. It solves the problem of poor removal efficiency of conventional alkanolamine desulfurizers for H2S and organic sulfur under low pressure. It is particularly suitable for the characteristics of hydrogenation tail gas in sulfur recovery units, which are characterized by low pressure, high temperature, high CO2 content, and organic form mainly composed of COS. Compared with conventional desulfurizers, the desulfurizer of this invention has a higher removal rate of H2S under normal pressure and can effectively remove organic sulfur. At the same time, it does not completely remove CO2, thus reducing the acid load in the desulfurizer and ensuring the removal of H2S and organic sulfur under low circulation conditions. The desulfurizer of this invention is suitable for desulfurizing hydrogenation tail gas in purification plants and refineries, effectively reducing SO2 emissions from the tail gas. Attached Figure Description

[0039] Figure 1 A schematic diagram of the structure of the desulfurization effect evaluation device for the desulfurizing agent provided in the embodiments and comparative examples;

[0040] Explanation of symbols for main components: Gas mixing tank 1, Gas preheating tank 2, Absorption tower 3, Purified gas separator 4, Lean liquid preheating tank 5, Lean liquid storage tank 6, Lean liquid cooling tank 7, Buffer tank 8, Rich liquid preheating tank 9, Regeneration tower 10, and Acid gas separator 11. Detailed Implementation

[0041] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0042] Example 1

[0043] This embodiment provides a desulfurizing agent for absorbing H2S and organic sulfur under normal pressure. The desulfurizing agent comprises the following components by mass percentage: 30% 4-tert-butylamino-1-butanol, 10% 2-(1,4-dimethylpiperazin-2-yl)acetic acid, 10% N,N-dimethylacetamide, and 50% deionized water.

[0044] The desulfurizing agent is prepared by the following steps: 4-tert-butylamino-1-butanol, 2-(1,4-dimethylpiperazin-2-yl)acetic acid and N,N-dimethylacetamide are added to deionized water according to the mass percentage of each component, and the mixture is stirred at 20-30°C and 30-50 r / min for 10-40 minutes to obtain the desulfurizing agent.

[0045] use Figure 1 The apparatus shown evaluates the desulfurization effect of the desulfurizing agent in this embodiment. The process parameters and evaluation results of the five evaluation tests are shown in Table 1. The temperature of the preheated raw gas is 25-28°C, the temperature at the top of the regeneration tower is controlled at 105°C, and the height of the absorber packing refers to the height of the lean liquor feed.

[0046] like Figure 1 As shown, the desulfurization effect evaluation device mainly includes: gas mixing tank 1, gas preheating tank 2, absorption tower 3, purified gas separator 4, lean liquor preheating tank 5, lean liquor storage tank 6, lean liquor cooling tank 7, buffer tank 8, rich liquor preheating tank 9, regeneration tower 10, and acid gas separator 11, etc.

[0047] Nitrogen or natural gas pipelines, hydrogen sulfide pipelines, carbon dioxide pipelines, and organic sulfur pipelines from the outside are connected to the inlet of the gas mixing tank 1, and the outlet of the gas mixing tank 1 is connected to the inlet of the gas preheating tank 2 via pipelines; the raw material gas for the evaluation test is mixed in the gas mixing tank 1 and then enters the gas preheating tank 2 for preheating.

[0048] The outlet of the gas preheating tank 2 is connected to the raw material gas inlet at the bottom of the absorption tower 3 via a pipeline. The gas outlet at the top of the absorption tower 3 is connected to the inlet of the purified gas separator 4 via a pipeline. The liquid outlet at the bottom of the absorption tower 3 is connected to the inlet of the rich liquid preheating tank 9 via a pipeline to the buffer tank 8. The outlet of the rich liquid preheating tank 9 is connected to the inlet of the regeneration tower 10 via a pipeline. The liquid outlet at the bottom of the regeneration tower 10 is connected to the inlet of the lean liquid cooling tank 7 via a pipeline. The gas outlet at the top of the regeneration tower 10 is connected to the acid gas separator 11 via a pipeline. The outlet of the lean liquid cooling tank 7 is connected to the inlet of the lean liquid storage tank 6 via a pipeline. The outlet of the lean liquid storage tank 6 is connected to the inlet of the lean liquid preheating tank 5 via a pipeline. The outlet of the preheating tank 5 is connected to the desulfurizing agent inlet of the absorption tower 3 via a pipeline. The preheated raw material gas enters the absorption tower 3 from the bottom. The desulfurizing agent, after being preheated in the lean liquid preheating tank 5, enters the absorption tower 3. The preheated raw material gas contacts and reacts with the preheated desulfurizing agent from bottom to top. The desulfurized gas flows out from the top of the absorption tower 3 and enters the purified gas separator 4 for separation to obtain purified gas. The used desulfurizing agent flows out from the liquid outlet at the bottom of the absorption tower 3 and is preheated in the rich liquid preheating tank 9 before entering the regeneration tower 10 for regeneration. The gas generated after regeneration is separated by the acid gas separator 11 to obtain acid gas. The liquid obtained after regeneration sequentially enters the lean liquid cooling tank 7, the lean liquid storage tank 6, and the lean liquid preheating tank 5 before re-entering the absorption tower 3 as a desulfurizing agent for recycling. The regeneration tower, absorption tower, and other equipment are all conventional in the field and are commercially available.

[0049] Table 1. Test data on H2S and organic sulfur removal by the desulfurizing agent in Example 1.

[0050]

[0051] The desulfurizer in this embodiment was evaluated using a lower gas-liquid ratio, a higher packing height, and a higher regeneration tower top temperature. The process parameters and evaluation results of the five evaluation tests are shown in Table 2, in which the regeneration tower top temperature was controlled at 107℃.

[0052] Table 2. Test data on H2S and organic sulfur removal by the desulfurizing agent in Example 1.

[0053]

[0054] Example 2

[0055] This embodiment provides a desulfurizing agent for absorbing H2S and organic sulfur under normal pressure. By mass percentage, the desulfurizing agent comprises the following components: 32% 6-tert-butylamino-1-hexanol, 5% (3-oxopiperazine-2-yl)acetic acid, 13% N,N-dimethyl-2,2-dimethoxyacetamide, and 50% deionized water. Figure 1 The apparatus shown was used to evaluate the desulfurization effect of the desulfurizing agent in this comparative example. The absorber packing height was 1 m, the lean liquor temperature was 39–40 °C, absorption was performed at atmospheric pressure, the gas-liquid ratio was 100, and other process parameters were the same as those in Table 1 of Example 1. The feed gas contained 2.0%–2.3% H2S, 30–32% CO2, and 100–120 mg / m³ COS. 3 Thiols are 50-60 mg / m³ 3 The H2S concentration in the purified gas is 7–9 mg / m³. 3 The CO2 removal rate is 8-12%, the COS removal rate is 62-71%, and the mercaptan removal rate is 39-42%.

[0056] Example 3

[0057] This embodiment provides a desulfurizing agent for absorbing H2S and organic sulfur under normal pressure. By mass percentage, the desulfurizing agent comprises the following components: 28% 4-tert-butylamino-1-butanol, 11% (3-oxo-1-piperazine)acetic acid, 9% 2-amino-N-pyridin-3-ylacetamide, and 52% deionized water. Figure 1 The apparatus shown was used to evaluate the desulfurization effect of the desulfurizing agent in this comparative example. The absorber packing height was 1 m, the lean liquor temperature was 39–40 °C, absorption was performed at atmospheric pressure, the gas-liquid ratio was 100, and other process parameters were the same as those in Table 1 of Example 1. The feed gas contained 2.0%–2.5% H2S, 28–32% CO2, and 100–120 mg / m³ COS. 3 Thiols are 50-60 mg / m³ 3 The H2S concentration in the purified gas is 3–7 mg / m³. 3 The CO2 removal rate is 6-11%, the COS removal rate is 62-69%, and the mercaptan removal rate is 50-59%.

[0058] Comparative Example 1

[0059] This comparative example uses a conventional 50% (w / w) aqueous solution of N-methyldiethanolamine (MDEA) as a desulfurizing agent. Figure 1 The apparatus shown was used to evaluate the desulfurization effect of the desulfurizing agent in this comparative example. The process parameters and evaluation results of the five evaluation tests are shown in Table 3. The temperature of the preheated raw gas was 25-28℃, and the temperature at the top of the regeneration tower was controlled at 105℃.

[0060] Table 3. Test data on the removal of H2S and organic sulfur by MDEA aqueous solution.

[0061]

[0062]

[0063] As can be seen from Tables 1 and 3, under the same evaluation conditions, the desulfurizer of the present invention is far superior to MDEA in removing H2S and organic sulfur.

[0064] Comparative Example 2

[0065] This comparative example provides a desulfurizing agent that uses the sterically hindered amine and additives of Example 1, but does not use an organic sulfur absorption promoter. By mass percentage, the desulfurizing agent comprises the following components: 40% 4-tert-butylamino-1-butanol, 10% N,N-dimethylacetamide, and 50% deionized water.

[0066] use Figure 1 The apparatus shown was used to evaluate the desulfurization effect of the desulfurizing agent in this comparative example. The absorber packing height was 1 m, the lean liquor temperature was 39–40 °C, absorption was performed at atmospheric pressure, the gas-liquid ratio was 100, and other process parameters were the same as those in Table 1 of Example 1. The feed gas contained 2.0%–2.3% H2S, 29%–32% CO2, and 100–120 mg / m³ COS. 3 Thiols are 50-55 mg / m³ 3 The H2S concentration in the purified gas is 20–22 mg / m³. 3 The CO2 removal rate is 5-7%, the COS removal rate is 13-18%, and the mercaptan removal rate is 26-30%.

[0067] Comparative Example 3

[0068] This comparative example provides a desulfurizing agent comprising, by mass percentage: 35% 4-tert-butylamino-1-butanol, 10% N,N-dimethylacetamide, 5% N,N-dihydroxyethylpiperazine, and 50% deionized water.

[0069] use Figure 1 The apparatus shown was used to evaluate the desulfurization effect of the desulfurizing agent in this comparative example. The absorber packing height was 1 m, the lean liquor temperature was 39–40 °C, absorption was performed at atmospheric pressure, the gas-liquid ratio was 100, and other process parameters were the same as those in Table 1 of Example 1. The feed gas contained 2.0%–2.3% H2S, 29%–32% CO2, and 100–120 mg / m³ COS. 3 Thiols are 50-55 mg / m³ 3 The H2S concentration in the purified gas is 18–25 mg / m³.3 The CO2 removal rate is 17-22%, the COS removal rate is 10-13%, and the mercaptan removal rate is 29-33%.

[0070] Comparative Example 4

[0071] This comparative example provides a desulfurizing agent comprising, by mass percentage: 35% 4-tert-butylamino-1-butanol, 10% 2-(1,4-dimethylpiperazin-2-yl)acetic acid, 5% piperazine, and 50% deionized water.

[0072] use Figure 1 The apparatus shown was used to evaluate the desulfurization effect of the desulfurizing agent in this comparative example. The absorber packing height was 1 m, the lean liquor temperature was 39–40 °C, absorption was performed at atmospheric pressure, the gas-liquid ratio was 100, and other process parameters were the same as those in Table 1 of Example 1. The feed gas contained 2.0%–2.3% H2S, 29%–32% CO2, and 100–120 mg / m³ COS. 3 Thiols are 50–54 mg / m³ 3 The H2S concentration in the purified gas is 87–93 mg / m³. 3 The CO2 removal rate is 98%–99%, the COS removal rate is 48%–55%, and the mercaptan removal rate is 34%–40%.

[0073] As can be seen from the above examples and comparative examples, MDEA has poor removal efficiency for organic sulfur under normal pressure, with an organic sulfur removal rate of <8%. Piperazine, a diamine, is significantly more basic than MDEA. Piperazine acts as an activator and reacts rapidly with COS. However, piperazine also causes problems with CO2 reaction, leading to a significant increase in the acid load in the solution and affecting the removal efficiency of hydrogen sulfide. To simultaneously and deeply remove H2S, the circulation rate needs to be greatly increased.

[0074] The desulfurizer of this invention employs a sterically hindered amine with high steric hindrance effect and a high pKa value. This increases the alkalinity of the desulfurizer, which is beneficial for enhancing its ability to absorb H2S, while also improving its selectivity, reducing the competitive absorption of CO2, and increasing the depth of H2S removal under low pressure. Furthermore, the desulfurizer of this invention introduces an organic sulfur absorption promoter with a special structure, which can effectively reduce the activation energy of the reaction between the sterically hindered amine and COS, thereby accelerating the hydrolysis rate of COS and improving the COS removal rate under low pressure. This allows the desulfurizer to maintain excellent H2S removal performance while also exhibiting significant COS removal capability. In addition, the desulfurizer of this invention also incorporates amide additives to improve its performance. Amide compounds are aprotic polar solvents that have a physical dissolving effect on organic sulfur and hydrogen sulfide. The amides selected in this invention have a steric hindrance effect, which synergistically works with the sterically hindered amine of this invention to increase the inhibition of CO2 and improve selectivity. Simultaneously, the amide-based additives used in this invention can undergo a tripolecular reaction with COS and the sterically hindered amine used in this invention, generating a complex with loosely bonded structures, thus forming a tripolecular structure that enhances COS removal. The generated complex exists instantaneously and regenerates upon heating due to bond breakage. Therefore, the desulfurizer of this invention does not completely remove CO2, thereby reducing the acid load in the desulfurizer and ensuring hydrogen sulfide removal under low circulation and atmospheric pressure conditions. It can also effectively remove organic sulfur.

Claims

1. A desulfurizing agent for absorbing hydrogen sulfide and organic sulfur under normal pressure, wherein the desulfurizing agent comprises the following components by mass percentage: 20-35% sterically hindered amine, 5-20% organic sulfur absorption promoter, 5-20% additives, and the balance being water; in, The organic sulfur absorption promoter includes one or a combination of several of 2-(1,4-dimethylpiperazin-2-yl)acetic acid, (3-oxo-1-piperazin)acetic acid, and (3-oxopiperazin-2-yl)acetic acid. The sterically hindered amine includes one or a combination of several of 4-tert-butylamino-1-butanol, 5-tert-butylamino-1-pentanol, and 6-tert-butylamino-1-hexanol; The adjuvant includes one or a combination of several of N,N-dimethylacetamide, N,N-dimethyl-2,2-dimethoxyacetamide, and 2-amino-N-pyridin-3-ylacetamide.

2. A method for preparing a desulfurizing agent for absorbing hydrogen sulfide and organic sulfur under normal pressure as described in claim 1, comprising the following steps: According to the mass percentage of each component, the sterically hindered amine, the organic sulfur absorption promoter, and the auxiliary agent are added to water and stirred for 10-40 minutes to obtain the desulfurizing agent.

3. The preparation method according to claim 2, wherein, The sterically hindered amine, the organic sulfur absorption promoter, and the auxiliary agent are added to water and stirred at a temperature of 20-30°C.

4. The preparation method according to claim 2, wherein, The stirring speed is 30-50 r / min.

5. The desulfurizing agent for absorbing hydrogen sulfide and organic sulfur under normal pressure as described in claim 1 is used as a desulfurizing agent for sulfur recovery and hydrogenation tail gas in natural gas purification plants and / or oil refineries.

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