Preparation method of corrosion-inhibition energy-saving high-efficiency desulfurizing agent

Abstract

The invention provides a preparation method of a corrosion-inhibition energy-saving efficient desulfurizer, and belongs to the technical field of desulfurizers, the preparation method comprises the following steps: S1, mixing tert-butylamine, 2-chloroethoxyethanol and methanol, reacting, cooling, adding a NaOH solution, carrying out reflux reaction, carrying out suction filtration, retaining filtrate, and carrying out cold reduced pressure distillation on the filtrate to obtain tert-butylamino ethoxyethanol; s2, uniformly mixing L-arginine, tetramethylammonium hydroxide and deionized water, and carrying out vortex stirring to obtain an L-arginine / tetramethylammonium ionic liquid; s3, mixing and stirring the radix salviae miltiorrhizae extract, tert-butylaminoethoxyethanol, L-arginine / tetramethylammonium ionic liquid, N-methyldiethanolamine and deionized water, so as to prepare the corrosion-inhibition energy-saving efficient desulfurizing agent. According to the invention, high H2S selectivity and energy conservation can be realized, and a certain corrosion inhibition effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of desulfurizers, and in particular to a method for preparing a corrosion-inhibiting, energy-saving and efficient desulfurizer. Background Art

[0002] At present, my country's natural gas industry has entered a period of rapid development. As a low-carbon clean fuel, natural gas will be more widely used in urban gas, industrial raw materials, chemical industry and power generation. With the increasing status of natural gas in the energy structure, the status of natural gas purification industry is becoming increasingly important. The mined natural gas often contains a certain amount of acidic gas H2S and CO2. Among them, H2S will cause corrosion of equipment pipelines during storage and transportation, and will seriously pollute the atmospheric environment after combustion. On the other hand, the sulfur recovered from natural gas through the Claus process is an important chemical raw material. At present, among all kinds of natural gas desulfurization processes, the most widely used is amine desulfurization technology. Commonly used desulfurization solvents include monoethanolamine, diethanolamine, diisopropanolamine, diglycolamine, N-methyldiethanolamine, etc. Among them, N-methyldiethanolamine has become the most widely used desulfurization solvent in amine desulfurization because of its advantages of high acid gas load, low corrosiveness and low foaming.

[0003] The relevant patent application documents are CN107433108A and CN105664698A. PetroChina Southwest Oil and Gas Field Natural Gas Research Institute has developed a CT8-5 desulfurizer with N-methyldiethanolamine as the main agent to remove hydrogen sulfide, which can effectively prevent foaming. However, since CO2 and other components in the raw gas are prone to produce heat-stable salts in the N-methyldiethanolamine system, the consumption of desulfurizers is increased, the desulfurization efficiency is reduced, and equipment corrosion is caused. This shows that for the complex raw gas types that need to be desulfurized and decarbonized in industry, conventional N-methyldiethanolamine aqueous solution cannot solve all problems. In particular, the content of H2S and CO2 in the raw gas is not too high, and the CO2 content is lower than 2% specified in the national standard for commercial natural gas (GB17820-2012). At this time, the requirement for the desulfurization solvent is to reduce the removal of CO2 while ensuring the purification degree of H2S, and to strengthen the selective absorption function of the solvent as much as possible to reduce energy consumption and improve the quality of the acid gas entering the sulfur recovery device. Therefore, the selective desulfurization process deserves more attention.

[0004] In recent years, people tend to seek solvents with higher activity and selectivity. Compared with commonly used alcohol amines, sterically hindered amines are characterized by one or two large alkyl groups or other groups replacing the hydrogen atoms on the amino groups in the alcohol amine molecules, thereby producing a larger steric effect. Although the sterically hindered amines 2-amino-2-methyl-1-propanol and 2-piperidinylethanol used for natural gas or refinery gas desulfurization have improved on H2S, they are also very effective in removing CO2; some scholars have combined the environmentally friendly characteristics of ionic liquids to conduct structure-activity studies of ionic liquids and successfully synthesized ionic liquids with metal salt groups. The results show that they have the ability to directly convert H2S into elemental sulfur. This desulfurization process is simple and easy to operate, but because the iron-based ionic liquid is acidic and a large amount of HCl accumulated during the desulfurization process escapes, it not only causes equipment corrosion, destroys the structure of the desulfurization liquid, but also increases viscosity, making the solubility of hydrogen sulfide in it smaller, thereby reducing the subsequent desulfurization efficiency. Therefore, the desulfurization effect of pure iron-based ionic liquids is not ideal.

[0005] Therefore, it is necessary to provide a method for preparing a corrosion-inhibiting, energy-saving and efficient desulfurizer to solve the problems existing in the above-mentioned prior art. Summary of the invention

[0006] In view of this, the present invention provides a method for preparing a corrosion-inhibiting and energy-saving high-efficiency desulfurizer, which can achieve high selectivity for H2S and energy saving while having a certain corrosion inhibition effect.

[0007] To achieve the above purpose, the specific scheme provided by the present invention is as follows: A method for preparing a corrosion-inhibiting, energy-saving and efficient desulfurizer comprises the following steps: S1, tert-butylamine, 2-chloroethoxyethanol and methanol are mixed, reacted, cooled, and then NaOH solution is added to perform reflux reaction, the filtrate is retained after suction filtration, and the filtrate is cold-distilled under reduced pressure to obtain tert-butylaminoethoxyethanol; S2, mixing L-arginine, tetramethylammonium hydroxide and deionized water uniformly, and vortex stirring to obtain L-arginine / tetramethylammonium ionic liquid; S3, the salvia miltiorrhiza extract, tert-butylaminoethoxyethanol, L-arginine / tetramethylammonium ion liquid, N-methyldiethanolamine and deionized water are mixed and stirred to prepare a corrosion-inhibiting energy-saving and efficient desulfurizer.

[0008] The present invention utilizes salvia miltiorrhiza extract as a corrosion inhibition component. The active ingredients in the salvia miltiorrhiza extract, such as tanshinone A, cryptotanshinone, tanshinone acid D, dihydrotanshinone and methylene tanshinone, are rich in polar groups of polyoxygen atoms, aromatic groups, unsaturated double bonds and conjugated structures, which can provide adsorption sites for metal atoms or ions, form a protective film on the metal surface, increase the surface coverage, thereby reducing the contact between the corrosive medium and the metal surface, and achieving a certain slow-release effect.

[0009] The preparation of the present invention adopts a simpler synthesis method, using excess tert-butylamine and 2-chloroethoxyethanol to react in a reactor, followed by reduced pressure distillation to obtain the product tert-butylaminoethoxyethanol (TBEE). TBEE has a secondary amine of a tert-butyl group, and the tert-butyl group is a group with a very large steric hindrance effect on the amino group, which makes the amino group present a unique chemical activity. Due to the presence of the steric hindrance group, the reaction activity of the hydrogen atom connected to the nitrogen atom of the steric hindrance amine is limited, thereby significantly reducing the reaction rate of CO2 and the steric hindrance amine, so that the absorption rate of TBEE to CO2 becomes low, while it has good chemical activity in the reaction with H2S, thereby better selectively absorbing H2S.

[0010] The present invention prepares L-arginine / tetramethylammonium ionic liquid. Tetramethylammonium hydroxide provides an alkaline environment, so that the nitrogen atom in the guanidine group of L-arginine loses a hydrogen ion, so that the nitrogen atom in the guanidine group carries a negative charge, thereby forming [Arg] - The negative ion form, tetramethylammonium ion (TMA + ) are combined together by electrostatic attraction to form an amino acid ionic liquid. It can be used as a promoter for the absorption of H2S. L-arginine contains primary amino groups, which makes it have a good ability to absorb acidic gases. In an alkaline environment, L-arginine is more reactive and promotes its solubility in water. L-arginine in the L-arginine / tetramethylammonium ionic liquid contains a carboxyl group and many amino groups, which can be combined with H2S. Adding L-arginine / tetramethylammonium ionic liquid to the desulfurizer will effectively increase the number of H2S adsorption sites, thereby improving the overall absorption capacity of the desulfurizer, and further help improve the effect of N-methyldiethanolamine in absorbing hydrogen sulfide, thereby reducing the formation of unnecessary salt by-products, reducing the consumption of the desulfurizer and reducing the energy required for the subsequent regeneration process, further achieving energy-saving effects. In addition, the alkaline guanidine group in L-arginine first reacts with H2S to generate amino acid hydrosulfide. In an alkaline environment, the guanidine group promotes the formation of carbamate by deprotonation. The formation of carbamate can stabilize the reaction intermediate and accelerate the further reaction with H2S, further improving the overall H2S absorption rate.

[0011] Optionally, in step S1, the reaction temperature is 150° C. and the reaction time is 3 h, and the reflux reaction temperature is 70° C. and the reaction time is 1 h.

[0012] Optionally, the mass concentration of the NaOH solution in step S1 is 2%.

[0013] Optionally, in step S1, the volume ratio of tert-butylamine to 2-chloroethoxyethanol is (2.5-3):1.

[0014] The invention utilizes excessive tert-butylamine to react with 2-chloroethoxyethanol, thereby simplifying the synthesis method.

[0015] Optionally, in step S2, the vortex stirring time is 15 to 20 minutes, and the mixing stirring time is 30 to 50 minutes.

[0016] Optionally, the Salvia miltiorrhiza extract in step S3 is obtained by washing the Salvia miltiorrhiza root with deionized water, drying it at 30°C until it is air-dried, cutting it into pieces of 1 to 1.5 cm in size, and performing Soxhlet extraction three times with distilled water at 95°C. The resulting solution is concentrated at -0.05 MPa and then dried at 85°C for 4 to 8 hours.

[0017] Optionally, in step S3, N-methyl-2-pyrrolidone is added to the mixture before mixing and stirring, and mixed with the salvia miltiorrhiza extract, tert-butylaminoethoxyethanol, L-arginine / tetramethylammonium ionic liquid, N-methyldiethanolamine and deionized water.

[0018] In the process of preparing the corrosion-inhibiting and energy-saving desulfurizer, the present invention further adds N-methyl-2-pyrrolidone as a physical solvent to capture acidic gases such as H2S through a physical adsorption mechanism. Its addition not only improves the absorption capacity of the acidic gas, but also reduces the energy required in the regeneration process because the physical solvent does not require additional heat to break the bond between the amine and the acidic gas, and at the same time forms a competitive effect with N-methyldiethanolamine, reduces the generation of heat-stable salts between hydrogen sulfide and amine solvents, and further achieves a certain energy-saving effect.

[0019] Optionally, the corrosion-inhibiting, energy-saving and high-efficiency desulfurizer comprises the following raw materials in parts by weight: 15-40 parts of Salvia miltiorrhiza extract, 80-100 parts of tert-butylaminoethoxyethanol, 30-60 parts of L-arginine / tetramethylammonium ion liquid, 20-40 parts of N-methyl-2-pyrrolidone, and 170-220 parts of N-methyldiethanolamine.

[0020] Optionally, the tert-butylaminoethoxyethanol comprises the following raw materials in parts by weight: 30-50 parts of tert-butylamine, 10-20 parts of 2-chloroethoxyethanol, 80-140 parts of methanol, and 30-50 parts of NaOH solution.

[0021] Optionally, the L-arginine / tetramethylammonium ionic liquid comprises the following raw materials in parts by weight: 7-10 parts of L-arginine, 30-40 parts of tetramethylammonium hydroxide, and 170-220 parts of deionized water.

[0022] The above technical solution of the present invention includes at least the following beneficial effects: 1. The present invention adopts salvia miltiorrhiza extract as a corrosion inhibition component. The active ingredients in the salvia miltiorrhiza extract are rich in polar groups of polyoxygen atoms, aromatic groups, unsaturated double bonds and conjugated structures, which can provide adsorption sites for metal atoms or ions and form a protective film on the metal surface, thereby reducing the contact between the corrosive medium and the metal surface, and further providing a certain corrosion inhibition effect.

[0023] 2. The present invention adopts a simpler synthesis method, using excess tert-butylamine and 2-chloroethoxyethanol to react, followed by reduced pressure distillation to obtain the product tert-butylaminoethoxyethanol (TBEE). TBEE has a secondary amine with a tert-butyl group, and the tert-butyl group is a group with a very large steric hindrance effect on the amino group. Due to the presence of the steric hindrance group, the reactivity of the hydrogen atom connected to the nitrogen atom of the steric hindrance amine is limited, thereby reducing the reaction rate of CO2 and the steric hindrance amine, making TBEE's absorption rate of CO2 lower, but having good chemical activity in the reaction with H2S, thereby better selectively absorbing H2S.

[0024] 3. The present invention prepares L-arginine / tetramethylammonium ion liquid. L-arginine contains primary amino groups, which makes it have good ability to absorb acidic gases. Tetramethylammonium hydroxide provides an alkaline environment to enhance the reactivity and solubility of L-arginine in water. The L-arginine anion in the L-arginine / tetramethylammonium ion liquid contains a carboxyl group and many amino groups, which can combine with H2S. Adding L-arginine / tetramethylammonium ion liquid to the desulfurizer will effectively increase the number of adsorption sites of H2S, thereby improving the absorption capacity of the overall desulfurizer, and further help improve the effect of N-methyldiethanolamine in absorbing hydrogen sulfide, reduce the formation of unnecessary salt by-products, thereby reducing the energy required in the regeneration process to achieve energy saving effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the absorption amount graph of H2S of Examples 1 to 6 of the present invention and Comparative Examples 1 to 3; Figure 2 This is a graph showing the CO2 absorption amount of Example 1 of the present invention and Comparative Examples 1 and 3. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described in combination with the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0027] Example 1 The roots of Salvia miltiorrhiza were washed with deionized water, dried at 30°C until air-dried, cut into 1 cm pieces, and subjected to Soxhlet extraction three times with distilled water at 95°C. The resulting solution was concentrated at -0.05 MPa and then dried at 85°C for 4 h to obtain Salvia miltiorrhiza extract.

[0028] 30 parts of tert-butylamine, 10 parts of 2-chloroethoxyethanol and 80 parts of methanol were mixed, reacted under autoclave at 150°C for 3 hours, cooled, added with 30 parts of 2% NaOH solution, refluxed at 70°C for 1 hour, filtered and retained the filtrate, and the filtrate was distilled under reduced pressure to obtain tert-butylaminoethoxyethanol.

[0029] 7 parts of L-arginine, 30 parts of tetramethylammonium hydroxide and 170 parts of deionized water were mixed evenly and vortexed for 15 minutes to obtain L-arginine / tetramethylammonium ion liquid; 15 parts of Salvia miltiorrhiza extract, 80 parts of tert-butylaminoethoxyethanol, 30 parts of L-arginine / tetramethylammonium ion liquid, 170 parts of N-methyldiethanolamine and 30 parts of N-methyl-2-pyrrolidone were mixed and stirred for 30 minutes to obtain a corrosion-inhibiting, energy-saving and efficient desulfurizer.

[0030] Example 2 The roots of Salvia miltiorrhiza were washed with deionized water, dried at 30°C until air-dried, cut into pieces of 1.5 cm in size, and subjected to Soxhlet extraction three times with distilled water at 95°C. The resulting solution was concentrated at -0.05 MPa and then dried at 85°C for 8 h to obtain the Salvia miltiorrhiza extract.

[0031] After mixing 50 parts of tert-butylamine, 20 parts of 2-chloroethoxyethanol and 140 parts of methanol, react under autoclave at 150°C for 3 hours. After cooling, add 50 parts of 2% NaOH solution, reflux and react at 70°C for 1 hour. After filtering, retain the filtrate, and distill the filtrate under reduced pressure to obtain tert-butylaminoethoxyethanol.

[0032] 10 parts of L-arginine, 40 parts of tetramethylammonium hydroxide and 220 parts of deionized water were mixed evenly and vortexed for 20 minutes to obtain L-arginine / tetramethylammonium ion liquid; 30 parts of Salvia miltiorrhiza extract, 100 parts of tert-butylaminoethoxyethanol, 60 parts of L-arginine / tetramethylammonium ion liquid, 220 parts of N-methyldiethanolamine and 20 parts of N-methyl-2-pyrrolidone were mixed and stirred for 50 minutes to obtain a corrosion-inhibiting, energy-saving and efficient desulfurizer.

[0033] Example 3 The roots of Salvia miltiorrhiza were washed with deionized water, dried at 30°C until air-dried, cut into pieces of 1.2 cm in size, and subjected to Soxhlet extraction three times with distilled water at 95°C. The resulting solution was concentrated at -0.05 MPa and then dried at 85°C for 6 h to obtain the Salvia miltiorrhiza extract.

[0034] After mixing 40 parts of tert-butylamine, 15 parts of 2-chloroethoxyethanol and 120 parts of methanol, react under autoclave at 150°C for 3 hours. After cooling, add 40 parts of 2% NaOH solution, reflux and react at 70°C for 1 hour. After filtering, retain the filtrate, and distill the filtrate under reduced pressure to obtain tert-butylaminoethoxyethanol.

[0035] 8 parts of L-arginine, 35 parts of tetramethylammonium hydroxide and 200 parts of deionized water were mixed evenly and vortexed for 20 minutes to obtain L-arginine / tetramethylammonium ion liquid; 20 parts of Salvia miltiorrhiza extract, 90 parts of tert-butylaminoethoxyethanol, 40 parts of L-arginine / tetramethylammonium ion liquid, 200 parts of N-methyldiethanolamine and 25 parts of N-methyl-2-pyrrolidone were mixed and stirred for 40 minutes to obtain a corrosion-inhibiting, energy-saving and efficient desulfurizer.

[0036] Example 4 The roots of Salvia miltiorrhiza were washed with deionized water, dried at 30°C until air-dried, cut into pieces of 1.3 cm in size, and subjected to Soxhlet extraction three times with distilled water at 95°C. The resulting solution was concentrated at -0.05 MPa and then dried at 85°C for 7 h to obtain Salvia miltiorrhiza extract.

[0037] 45 parts of tert-butylamine, 17 parts of 2-chloroethoxyethanol and 100 parts of methanol were mixed, reacted under autoclave at 150°C for 3 hours, cooled, added with 35 parts of 2% NaOH solution, refluxed at 70°C for 1 hour, filtered and retained the filtrate, and the filtrate was distilled under reduced pressure to obtain tert-butylaminoethoxyethanol.

[0038] 8 parts of L-arginine, 35 parts of tetramethylammonium hydroxide and 190 parts of deionized water were mixed evenly and vortexed for 16 minutes to obtain L-arginine / tetramethylammonium ion liquid; 25 parts of Salvia miltiorrhiza extract, 95 parts of tert-butylaminoethoxyethanol, 45 parts of L-arginine / tetramethylammonium ion liquid, 210 parts of N-methyldiethanolamine and 35 parts of N-methyl-2-pyrrolidone were mixed and stirred for 45 minutes to obtain a corrosion-inhibiting, energy-saving and efficient desulfurizer.

[0039] Example 5 The roots of Salvia miltiorrhiza were washed with deionized water, dried at 30°C until air-dried, cut into pieces of 1.5 cm in size, and subjected to Soxhlet extraction three times with distilled water at 95°C. The resulting solution was concentrated at -0.05 MPa and then dried at 85°C for 6 h to obtain the Salvia miltiorrhiza extract.

[0040] 35 parts of tert-butylamine, 17 parts of 2-chloroethoxyethanol and 120 parts of methanol were mixed, reacted under autoclave at 150°C for 3 hours, cooled, added with 40 parts of 2% NaOH solution, refluxed at 70°C for 1 hour, filtered and retained the filtrate, and the filtrate was distilled under reduced pressure to obtain tert-butylaminoethoxyethanol.

[0041] 9 parts of L-arginine, 37 parts of tetramethylammonium hydroxide and 190 parts of deionized water were mixed evenly and vortexed for 20 minutes to obtain L-arginine / tetramethylammonium ion liquid; 20 parts of Salvia miltiorrhiza extract, 90 parts of tert-butylaminoethoxyethanol, 50 parts of L-arginine / tetramethylammonium ion liquid and 220 parts of N-methyldiethanolamine were mixed and stirred for 40 minutes to obtain a corrosion-inhibiting, energy-saving and efficient desulfurizer.

[0042] Example 6 The roots of Salvia miltiorrhiza were washed with deionized water, dried at 30°C until air-dried, cut into 1 cm pieces, and subjected to Soxhlet extraction three times with distilled water at 95°C. The resulting solution was concentrated at -0.05 MPa and then dried at 85°C for 7 h to obtain the Salvia miltiorrhiza extract.

[0043] After mixing 40 parts of tert-butylamine, 12 parts of 2-chloroethoxyethanol and 120 parts of methanol, react under autoclave at 150°C for 3 hours. After cooling, add 36 parts of 2% NaOH solution, reflux and react at 70°C for 1 hour. After filtering, retain the filtrate, and distill the filtrate under reduced pressure to obtain tert-butylaminoethoxyethanol.

[0044] 10 parts of L-arginine, 35 parts of tetramethylammonium hydroxide and 190 parts of deionized water were mixed evenly and vortexed for 15 minutes to obtain L-arginine / tetramethylammonium ion liquid; 15 parts of Salvia miltiorrhiza extract, 90 parts of tert-butylaminoethoxyethanol, 50 parts of L-arginine / tetramethylammonium ion liquid, 220 parts of N-methyldiethanolamine and 40 parts of N-methyl-2-pyrrolidone were mixed and stirred for 50 minutes to obtain a corrosion-inhibiting, energy-saving and efficient desulfurizer.

[0045] The present invention also carries out comparative examples and related tests.

[0046] Comparative Example 1 Compared with Example 1, the difference is that tert-butylaminoethoxyethanol is not prepared, and the other components and preparation steps are completely the same, and a corrosion-inhibiting, energy-saving and efficient desulfurizer is prepared.

[0047] Comparative Example 2 Compared with Example 1, the difference is that the salvia miltiorrhiza extract is not added, and the other components and preparation steps are completely the same, so as to prepare a corrosion-inhibiting, energy-saving and efficient desulfurizer.

[0048] Comparative Example 3 Compared with Example 1, the difference is that L-arginine / tetramethylammonium ionic liquid is not prepared, and other components and preparation steps are completely the same, and a corrosion-inhibiting, energy-saving and efficient desulfurizer is prepared.

[0049] Performance testing The corrosion-inhibiting, energy-saving and high-efficiency desulfurizers obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were subjected to basic performance tests according to the national standard GB / T42526-2023 for alcoholamine desulfurization and decarbonization agents. The basic performance test results are shown in Table 1.

[0050] Table 1

[0051] As shown in Table 1, the solidification points of Examples 1 to 6 are ≤-25°C and the foaming tendency is ≤50.0 mm, which are in line with the technical indicators of GB / T42526-2023. The foaming tendency of Comparative Example 1 is significantly improved due to the absence of tert-butylaminoethoxyethanol.

[0052] The desulfurizer obtained in Examples 1 to 6 and Comparative Examples 1 to 3 was first measured for pH value by pH meter, and then placed in desulfurization device to desulfurize coke oven gas. The treatment process conditions were: coke oven gas flow rate: 100L / h; desulfurizer flow rate: 2L / h; air aeration flow rate: 40L / h; temperature: 20°C; after 72h of desulfurization treatment, the desulfurization effect was tested. And the corrosion inhibition performance of Examples 1 to 6 and Comparative Examples 1 to 3 was evaluated by the static corrosion rate evaluation method of normal pressure in SY / T5405-1996 "Test Method and Evaluation Index of Corrosion Inhibitor Performance for Acidification", and the prepared test piece was subjected to a 4h static hanging test in 15% hydrochloric acid solution and 90°C water bath to determine its corrosion rate. The test results of pH value, corrosion rate, etc. are shown in Table 2.

[0053] Table 2

[0054] As shown in Table 2, the desulfurization efficiency of the desulfurizers obtained in Examples 1 to 6 after running in the desulfurization device for 72 hours is above 98.5%, indicating that the desulfurizer of the present invention has high desulfurization efficiency, can make the coke oven gas reach the purification standard, and no precipitation is produced in the desulfurizer after running for 72 hours, and the stability is excellent. Comparative Example 1 does not add tert-butylaminoethoxyethanol and Comparative Example 3 does not add L-arginine / tetramethylammonium ion liquid, so the desulfurization efficiency is significantly reduced. Comparative Example 2 does not add Salvia miltiorrhiza extract, so the corrosion rate is significantly increased. Example 5 does not add N-methyl-2-pyrrolidone, which also makes the desulfurization effect less than ideal.

[0055] Figure 1For the corrosion-inhibiting, energy-saving and high-efficiency desulfurizers prepared in Examples 1 to 6 and Comparative Examples 1 to 3, 5 ml of the corrosion-inhibiting, energy-saving and high-efficiency desulfurizers were respectively diluted with deionized water to a volume concentration of 50% and placed in an absorption bottle. At 30°C and a H2S partial pressure of 10 kPa, H2S gas with a concentration of 10 vol% was bubbled into the diluted corrosion-inhibiting, energy-saving and high-efficiency desulfurizer at a flow rate of 30 mL / min. The saturated absorption amount of H2S by the corrosion-inhibiting, energy-saving and high-efficiency desulfurizers prepared in Example 1 and Comparative Examples 1 to 3 and the time required to reach saturation were measured.

[0056] Combination Figure 1 It can be seen that the amount of H2S absorbed by Examples 1 to 6 and Comparative Examples 1 to 3 during the period of 0 to 90 minutes is relatively stable, basically increasing linearly, and then slowly increasing and decreasing, and the mass almost stops increasing between 180 and 210 minutes, reaching saturation. The saturated absorption amount of H2S absorbed by Examples 1 to 6 is between 5.0 and 5.5 mol / kg, which is much higher than the saturated absorption amount of H2S absorbed by Comparative Examples 1 to 3. Among them, the saturated absorption amount of H2S is significantly reduced in Comparative Example 3 because L-arginine / tetramethylammonium ion liquid is not added.

[0057] Figure 2 According to the above experimental steps, CO2 gas with a concentration of 10 vol% was bubbled into the diluted corrosion-inhibiting, energy-saving and high-efficiency desulfurizer at a flow rate of 30 mL / min, and the absorption amount of CO2 gas by the corrosion-inhibiting, energy-saving and high-efficiency desulfurizer prepared in Example 1, Comparative Example 1 and Comparative Example 3 within a certain period of time was measured.

[0058] Combination Figure 2 It can be seen that the selective absorption capacity of Example 1 is significantly enhanced, while the selective absorption capacity of Comparative Example 1 is reduced due to the lack of preparation of tert-butylaminoethoxyethanol, and the absorption of CO2 is increased. In addition, Comparative Example 3 is not prepared with L-arginine / tetramethylammonium ion liquid, so the absorption capacity of H2S is reduced, thereby affecting its selective absorption capacity.

[0059] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a corrosion-inhibiting, energy-saving and efficient desulfurizer, characterized in that: The following steps are involved: S1, tert-butylamine, 2-chloroethoxyethanol and methanol are mixed, reacted, cooled, and then NaOH solution is added to perform reflux reaction, the filtrate is retained after suction filtration, and the filtrate is cold-distilled under reduced pressure to obtain tert-butylaminoethoxyethanol; S2, mixing L-arginine, tetramethylammonium hydroxide and deionized water uniformly, and vortex stirring to obtain L-arginine / tetramethylammonium ionic liquid; S3. Mix and stir the salvia miltiorrhiza extract, tert-butylaminoethoxyethanol, L-arginine / tetramethylammonium ion liquid, N-methyldiethanolamine and deionized water to prepare a corrosion-inhibiting, energy-saving and efficient desulfurizer.

2. The method for preparing a corrosion-inhibiting, energy-saving and efficient desulfurizer according to claim 1, characterized in that: The reaction temperature in step S1 is 150° C. and the reaction time is 3 h, and the reflux reaction temperature is 70° C. and the reaction time is 1 h.

3. The method for preparing a corrosion-inhibiting, energy-saving and efficient desulfurizer according to claim 1, characterized in that: The mass concentration of the NaOH solution in step S1 is 2%.

4. The method for preparing a corrosion-inhibiting, energy-saving and efficient desulfurizer according to claim 1, characterized in that: In step S1, the volume ratio of tert-butylamine to 2-chloroethoxyethanol is (2.5-3):

1.

5. The method for preparing a corrosion-inhibiting, energy-saving and efficient desulfurizer according to claim 1, characterized in that: In step S2, the vortex stirring time is 15 to 20 minutes, and the mixing stirring time is 30 to 50 minutes.

6. The method for preparing a corrosion-inhibiting, energy-saving and efficient desulfurizer according to claim 1, characterized in that: In step S3, the salvia miltiorrhiza extract is obtained by washing the root of salvia miltiorrhiza with deionized water, drying it at 30°C until it is air-dried, cutting it into pieces of 1 to 1.5 cm in size, performing Soxhlet extraction three times with distilled water at 95°C, concentrating the resulting solution at -0.05MPa, and then drying it at 85°C for 4 to 8h.

7. The method for preparing a corrosion-inhibiting, energy-saving and efficient desulfurizer according to claim 1, characterized in that: In the step S3, N-methyl-2-pyrrolidone is added to the mixture before mixing and stirring, and mixed with the Danshen extract, tert-butylaminoethoxyethanol, L-arginine / tetramethylammonium ionic liquid, N-methyldiethanolamine and deionized water.

8. The method for preparing a corrosion-inhibiting, energy-saving and efficient desulfurizer according to claim 1, characterized in that: The corrosion-inhibiting, energy-saving and efficient desulfurizer comprises the following raw materials in parts by weight: 15-30 parts of salvia miltiorrhiza extract, 80-100 parts of tert-butylaminoethoxyethanol, 30-60 parts of L-arginine / tetramethylammonium ion liquid, 20-40 parts of N-methyl-2-pyrrolidone and 170-220 parts of N-methyldiethanolamine.

9. The method for preparing a corrosion-inhibiting, energy-saving and efficient desulfurizer according to claim 8, characterized in that: The tert-butylaminoethoxyethanol comprises the following raw materials in parts by weight: 30-50 parts of tert-butylamine, 10-20 parts of 2-chloroethoxyethanol, 80-140 parts of methanol, and 30-50 parts of NaOH solution.

10. The method for preparing a corrosion-inhibiting, energy-saving and efficient desulfurizer according to claim 8, characterized in that: The L-arginine / tetramethylammonium ionic liquid comprises the following raw materials in parts by weight: 7-10 parts of L-arginine, 30-40 parts of tetramethylammonium hydroxide, and 170-220 parts of deionized water.

Images