Novel selective absorption desulfurization and decarbonization solvent for selectively and deeply removing hydrogen sulfide

Abstract

The invention relates to the technical field of desulfurization and decarburization, and discloses a novel selective absorption desulfurization and decarburization solvent for selectively and deeply removing hydrogen sulfide. Comprising the following components in parts by weight: 10-15 parts of N-methyldiethanolamine, 3-6 parts of a metal organic framework, 5-10 parts of isopropanol, 4-6 parts of a surfactant, 1-3 parts of epoxy nano silicon dioxide and 2-4 parts of water. The preparation method comprises the following steps: adding N-methyldiethanolamine, a metal organic framework, isopropanol, a surfactant, epoxy nano silicon dioxide and water into a stirrer, and stirring for 10-15 minutes to obtain the novel selective absorption desulfurization and decarbonization solvent for selectively and deeply removing hydrogen sulfide. The novel selective absorption desulfurization and decarbonization solvent for selectively and deeply removing hydrogen sulfide can selectively and deeply remove hydrogen sulfide, and has good separation performance on carbon dioxide.

Description

Technical Field

[0001] The present invention relates to the technical field of desulfurization and decarbonization, and particularly to a novel selective absorption desulfurization and decarbonization solvent for selectively and deeply removing hydrogen sulfide. Background Art

[0002] For the current deep purification of gases with a high CO2 / H2S ratio, not only is the purification degree not ideal, but also the thermal energy consumption and power consumption of the device are relatively high. Traditional desulfurization methods have some limitations, such as limited desulfurization accuracy, difficult solvent regeneration, and increased energy consumption due to the co-absorption of carbon dioxide. Therefore, it is of great significance to develop a novel solvent with high selectivity, deep desulfurization ability, and effective separation of hydrogen sulfide and carbon dioxide. Some existing desulfurization solvents often inevitably absorb a large amount of carbon dioxide while removing hydrogen sulfide, which not only increases the energy consumption of subsequent solvent regeneration but also reduces the desulfurization efficiency. Therefore, how to avoid this phenomenon is the key to solving the problem. Summary of the Invention

[0003] (I) Technical Problems to be Solved Aiming at the deficiencies of the existing technology, the present invention provides a novel selective absorption desulfurization and decarbonization solvent for selectively and deeply removing hydrogen sulfide, which can selectively and deeply remove hydrogen sulfide and has good separation performance for carbon dioxide.

[0004] (II) Technical Solutions To achieve the above object, the present invention provides the following technical solutions: A novel selective absorption desulfurization and decarbonization solvent for selectively and deeply removing hydrogen sulfide, comprising the following weight components: 10 - 15 parts by weight of N-methyldiethanolamine, 3 - 6 parts by weight of metal-organic framework, 5 - 10 parts by weight of isopropanol, 4 - 6 parts by weight of surfactant, 1 - 3 parts by weight of epoxy nano-silica, and 2 - 4 parts by weight of water.

[0005] Further, the preparation method of the surfactant is as follows: (1) Add 45 - 50 mL of ethanol, 4 - 5 mmol of 4-(2-hydroxyethoxy)benzaldehyde, and 3 - 6 mmol of 3,5-bis(hydroxymethyl)aniline to a reaction vessel for condensation reaction. After completion, concentrate the solution, wash with ether to obtain a Schiff base intermediate; (2) Add 2 - 3 mmol of L-histidine and 2.5 - 3 mmol of the Schiff base intermediate to 40 - 60 mL of N,N-dimethylformamide solvent, stir and mix, then continue to add 0.01 - 0.013 mmol of catalyst, stir and react. After completion, perform vacuum distillation, wash and dry to obtain the surfactant.

[0006] Further, the reaction temperature in (1) is 44 - 50 °C.

[0007] Further, it is characterized in that the reaction time in (1) is 3 - 5 h.

[0008] Further, the reaction temperature in (2) is 65 - 75 °C.

[0009] Further, the reaction time in (2) is 4 - 6 h.

[0010] Further, the catalyst in (2) is p - toluenesulfonic acid.

[0011] Further, the preparation method of the novel selective absorption desulfurization and decarbonization solvent for deep desulfurization of hydrogen sulfide is as follows: Add N - methyldiethanolamine, metal - organic framework, isopropanol, surfactant, epoxy nano - silica, and water into a stirrer and stir for 10 - 15 min to obtain the novel selective absorption desulfurization and decarbonization solvent for deep desulfurization of hydrogen sulfide.

[0012] (III) Beneficial technical effects In the present invention, by adding N - methyldiethanolamine, metal - organic framework, isopropanol, surfactant, epoxy nano - silica, and water into a stirrer and stirring for 10 - 15 min, a novel selective absorption desulfurization and decarbonization solvent for deep desulfurization of hydrogen sulfide is obtained.

[0013] The novel selective absorption desulfurization and decarbonization solvent for deep desulfurization of hydrogen sulfide of the present invention has high selectivity and deep desulfurization ability, can effectively remove hydrogen sulfide in sulfur - containing gas, and has less carbon dioxide absorption at the same time, achieving good separation.

[0014] During the stirring process, the epoxy groups in the epoxy nano - silica will undergo ring - opening reaction with the amino groups in the surfactant, forming a tight cross - linked network with each other, providing more adsorption sites and achieving a better adsorption effect; the nitrogen - hydrogen bond in the surfactant will absorb hydrogen sulfide to achieve a better adsorption effect. The metal - organic framework and the surfactant play a coordinating role in adsorbing hydrogen sulfide gas. Specific embodiments

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0016] The preparation method of the metal-organic framework is as follows: Referring to the reference "Study on the Preparation and Gas Adsorption and Separation Performance of Metal-Organic Framework Materials", 0.835 mmol (242.5 mg) of nickel nitrate hexahydrate and 0.25 mmol (68.5 mg) of L1 are dissolved in 10 mL of an equal-volume mixed solution of N,N-dimethylformamide, ethanol, and water, placed in a 20 mL glass vial, and reacted at 100 °C for 12 h to obtain green microcrystals. The microcrystals are soaked in N,N-dimethylformamide for two days, with the liquid replaced every six hours, and then soaked in methanol for two days, with the liquid replaced every six hours. After soaking, it is dried in a vacuum oven at 130 °C for 6 hours to obtain the metal-organic framework.

[0017] The preparation of epoxy nano-silica: Referring to the reference "Modification of Nano-Silica with Silane Coupling Agent KH-560", a certain amount of nano-silica is weighed and added to 20 mL of toluene. It is ultrasonically dispersed at room temperature for 30 min with a KQ-300E type ultrasonic cleaner (300 W) to obtain a uniform suspension. Then, silane coupling agent KH-560 is added to it and ultrasonically treated for another 3 - 4 min and transferred to a 100 mL four-necked flask equipped with a reflux condenser and a powerful electric stirrer, and stirred and reacted at a set oil bath temperature. The reacted slurry is centrifuged at room temperature at a speed of 12,000 r / min with a CT15RT bench-top high-speed refrigerated centrifuge to obtain epoxy nano-silica. Example 1

[0018] (1) Add 45 mL of ethanol, 4 mmol of 4-(2-hydroxyethoxy)benzaldehyde, and 3 mmol of 3,5-bis(hydroxymethyl)aniline to the reaction vessel, carry out a condensation reaction at 44 °C for 3 h. After completion, the solution is concentrated and washed with ether to obtain a Schiff base intermediate; (2) Add 2 mmol of L-histidine and 2.5 mmol of the Schiff base intermediate to 40 mL of N,N-dimethylformamide solvent, stir and mix at 65 °C for 4 h. Then, add 0.01 mmol of p-toluenesulfonic acid catalyst and stir the reaction. After completion, carry out vacuum distillation, washing, and drying to obtain a surfactant; (3) Add 10 parts by weight of N-methyldiethanolamine, 3 parts by weight of the metal-organic framework, 5 parts by weight of isopropanol, 4 parts by weight of the surfactant, 1 part by weight of epoxy nano-silica, and 2 parts by weight of water to a stirrer and stir for 10 min to obtain a novel selective absorption desulfurization and decarbonization solvent for deep removal of hydrogen sulfide. Example 2

[0019] (1) Add 50 mL of ethanol, 5 mmol of 4-(2-hydroxyethoxy)benzaldehyde, and 6 mmol of 3,5-bis(hydroxymethyl)aniline to a reaction vessel, carry out a condensation reaction at 50 °C for 5 h, and after completion, concentrate the solution and wash it with ether to obtain a Schiff base intermediate; (2) Add 3 mmol of L-histidine and 3 mmol of the Schiff base intermediate to 60 mL of N,N-dimethylformamide solvent, stir and mix at 75 °C for 6 h, then continue to add 0.013 mmol of p-toluenesulfonic acid catalyst and stir the reaction. After completion, carry out vacuum distillation, wash and dry to obtain a surfactant; (3) Add 15 parts by weight of N-methyldiethanolamine, 6 parts by weight of metal-organic framework, 10 parts by weight of isopropanol, 6 parts by weight of surfactant, 3 parts by weight of epoxy nano-silica, and 4 parts by weight of water to a stirrer and stir for 15 min to obtain a novel selective absorption desulfurization and decarbonization solvent for deep removal of hydrogen sulfide. Example 3

[0020] (1) Add 48 mL of ethanol, 4.5 mmol of 4-(2-hydroxyethoxy)benzaldehyde, and 5 mmol of 3,5-bis(hydroxymethyl)aniline to a reaction vessel, carry out a condensation reaction at 47 °C for 4 h, and after completion, concentrate the solution and wash it with ether to obtain a Schiff base intermediate; (2) Add 2.5 mmol of L-histidine and 2.8 mmol of the Schiff base intermediate to 50 mL of N,N-dimethylformamide solvent, stir and mix at 70 °C for 5 h, then continue to add 0.011 mmol of p-toluenesulfonic acid catalyst and stir the reaction. After completion, carry out vacuum distillation, wash and dry to obtain a surfactant; (3) Add 12 parts by weight of N-methyldiethanolamine, 5 parts by weight of metal-organic framework, 7 parts by weight of isopropanol, 5 parts by weight of surfactant, 2 parts by weight of epoxy nano-silica, and 3 parts by weight of water to a stirrer and stir for 12 min to obtain a novel selective absorption desulfurization and decarbonization solvent for deep removal of hydrogen sulfide. Example 4

[0021] (1) Add 45 mL of ethanol, 4 mmol of 4-(2-hydroxyethoxy)benzaldehyde, and 3 mmol of 3,5-bis(hydroxymethyl)aniline to a reaction vessel, carry out a condensation reaction at 44 °C for 3 h, and after completion, concentrate the solution and wash it with ether to obtain a Schiff base intermediate; (2) Add 3 mmol of L-histidine and 3 mmol of the Schiff base intermediate to 60 mL of N,N-dimethylformamide solvent, stir and mix at 75 °C for 6 h, then continue to add 0.013 mmol of p-toluenesulfonic acid catalyst and stir the reaction. After completion, carry out vacuum distillation, wash and dry to obtain a surfactant; (3) Add 12 parts by weight of N-methyldiethanolamine, 5 parts by weight of metal-organic framework, 7 parts by weight of isopropanol, 5 parts by weight of surfactant, 2 parts by weight of epoxy nano-silica, and 3 parts by weight of water into a stirrer and stir for 12 min to obtain a novel selective absorption desulfurization and decarbonization solvent for deep removal of hydrogen sulfide. Example 5

[0022] (1) Add 50 mL of ethanol, 5 mmol of 4-(2-hydroxyethoxy)benzaldehyde, and 6 mmol of 3,5-bis(hydroxymethyl)aniline into a reaction vessel, carry out a condensation reaction at 50 °C for 5 h, concentrate the solution after completion, and wash with ether to obtain a Schiff base intermediate; (2) Add 2.5 mmol of L-histidine and 2.8 mmol of the Schiff base intermediate into 50 mL of N,N-dimethylformamide solvent, stir and mix at 70 °C for 5 h, continue to add 0.011 mmol of p-toluenesulfonic acid catalyst thereto, stir and react, carry out reduced pressure distillation after completion, wash and dry to obtain a surfactant; (3) Add 10 parts by weight of N-methyldiethanolamine, 3 parts by weight of metal-organic framework, 5 parts by weight of isopropanol, 4 parts by weight of surfactant, 1 part by weight of epoxy nano-silica, and 2 parts by weight of water into a stirrer and stir for 10 min to obtain a novel selective absorption desulfurization and decarbonization solvent for deep removal of hydrogen sulfide. Example 6

[0023] (1) Add 48 mL of ethanol, 4.5 mmol of 4-(2-hydroxyethoxy)benzaldehyde, and 5 mmol of 3,5-bis(hydroxymethyl)aniline into a reaction vessel, carry out a condensation reaction at 47 °C for 4 h, concentrate the solution after completion, and wash with ether to obtain a Schiff base intermediate; (2) Add 2 mmol of L-histidine and 2.5 mmol of the Schiff base intermediate into 40 mL of N,N-dimethylformamide solvent, stir and mix at 65 °C for 4 h, continue to add 0.01 mmol of p-toluenesulfonic acid catalyst thereto, stir and react, carry out reduced pressure distillation after completion, wash and dry to obtain a surfactant; (3) Add 15 parts by weight of N-methyldiethanolamine, 6 parts by weight of metal-organic framework, 10 parts by weight of isopropanol, 6 parts by weight of surfactant, 3 parts by weight of epoxy nano-silica, and 4 parts by weight of water into a stirrer and stir for 15 min to obtain a novel selective absorption desulfurization and decarbonization solvent for deep removal of hydrogen sulfide.

[0024] Comparative Example 1 The difference between this comparative example and Example 1 is that a Schiff base intermediate is used instead of the surfactant.

[0025] Comparative Example 2 The difference between this comparative example and Example 1 is that no surfactant is added.

[0026] The solvents prepared in Examples 1-6 and Comparative Examples 1-2 were filled into an absorption tower, and a simulated sulfur-containing gas containing H2S (concentration of 10,000 ppm) and CO2 (concentration of 30%) was introduced. The absorption temperature was controlled at 30 °C and the absorption pressure was 2 MPa for gas detection.

[0027] Project Desulfurization Degree (%) Decrease Concentration of Carbon Dioxide (%) Example 1 99.99 4.8 Example 2 99.99 4.3 Example 3 99.99 4.6 Example 4 99.99 4.7 Example 5 99.99 4.5 Example 6 99.99 4.6 Comparative Example 1 95.67 5.3 Comparative Example 2 97.80 6.7 As can be seen from Table 1, Examples 1-6 of the present invention have a high selective absorption ability for H2S compared with Comparative Examples 1-2.

[0028] It should be noted that in this article, the terms "including", "comprising" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0029] The above examples are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing examples, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

[0030] Those skilled in the art should understand that the above are only several specific embodiments of the present invention, rather than all embodiments. It should be pointed out that many variations and improvements can be made for those of ordinary skill in the art, and all variations or improvements that do not exceed the scope defined by the claims should be regarded as the protection scope of the present invention.

Claims

1. A novel selective absorption desulfurization and decarbonization solvent for selective deep removal of hydrogen sulfide, characterized in that It comprises the following weight components: 10-15 parts by weight of N-methyldiethanolamine, 3-6 parts by weight of metal-organic framework, 5-10 parts by weight of isopropanol, 4-6 parts by weight of surfactant, 1-3 parts by weight of epoxy nano-silica, and 2-4 parts by weight of water.

2. The novel selective absorption desulfurization and decarbonization solvent for selectively and deeply removing hydrogen sulfide according to claim 1, wherein The preparation method of the surfactant is as follows: (1) Add 45-50 mL of ethanol, 4-5 mmol of 4-(2-hydroxyethoxy)benzaldehyde, and 3-6 mmol of 3,5-bis(hydroxymethyl)aniline to a reaction vessel for condensation reaction. After completion, concentrate the solution and wash it with ether to obtain a Schiff base intermediate; (2) Add 2-3 mmol of L-histidine and 2.5-3 mmol of the Schiff base intermediate to 40-60 mL of N,N-dimethylformamide solvent, stir and mix. Then continue to add 0.01-0.013 mmol of catalyst, stir and react. After completion, perform vacuum distillation, wash and dry to obtain the surfactant.

3. The novel selective absorption desulfurization and decarbonization solvent for selectively and deeply removing hydrogen sulfide according to claim 2, characterized in that, The reaction temperature in (1) is 44-50 °C.

4. The novel selective absorption desulfurization and decarbonization solvent for selectively and deeply removing hydrogen sulfide according to claim 2, characterized in that, The reaction time in (1) is 3-5 h.

5. The novel selective absorption desulfurization and decarbonization solvent for selectively and deeply removing hydrogen sulfide according to claim 2, wherein, The reaction temperature in (2) is 65-75 °C.

6. The novel selective absorption desulfurization and decarbonization solvent for selectively and deeply removing hydrogen sulfide according to claim 2, characterized in that, The reaction time in (2) is 4-6 h.

7. The novel selective absorption desulfurization and decarbonization solvent for selectively and deeply removing hydrogen sulfide according to claim 2, characterized in that, The catalyst in (2) is p-toluenesulfonic acid.

8. A novel selective absorption desulfurization and decarbonization solvent for selectively and deeply removing hydrogen sulfide as described in any one of claims 1-7, characterized in that, The preparation method of the novel selective absorption desulfurization and decarbonization solvent for deep desulfurization of hydrogen sulfide selectively is: Add N-methyldiethanolamine, metal-organic framework, isopropanol, surfactant, epoxy nano-silica, and water to a stirrer and stir for 10-15 min to obtain the novel selective absorption desulfurization and decarbonization solvent for deep desulfurization of hydrogen sulfide selectively.