Adsorption desulfurizer and preparation method thereof

Abstract

The invention belongs to the technical field of catalysts, and relates to an adsorption desulfurizer and a preparation method thereof. According to the invention, an organic solvent is used as a reaction solvent, and zircon salt, transition metal salt and a ligand react to obtain the adsorption desulfurizer; the adsorption desulfurizing agent is a zirconium-based bimetal organic framework compound M-Zr-MOF containing a transition metal M; wherein the transition metal M is selected from Cu < 2 + >, Fe < 3 + >, Co < 2 + >, Mn < 2 + > and Ce < 3 + >, and the ligand is selected from terephthalic acid or trimesic acid with at least one organic amine substituent on a benzene ring. The preparation method is mild in operation condition, and the prepared adsorption desulfurizer can be repeatedly used and is suitable for removing various sulfides.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to an adsorption desulfurizing agent and its preparation method. Background Technology

[0002] Natural gas is an important fuel and chemical raw material used in various industrial processes. However, the small amounts of sulfides (H2S, CS2, CH3SH, CH3SCH3, etc.) contained in natural gas not only corrode equipment but also poison downstream catalysts. Therefore, the development of natural gas desulfurizing agents is of great significance.

[0003] Inorganic sulfides (H2S) can be removed using various methods, while organic sulfides (thiols CH3SH, sulfides CH3SCH3, etc.) cannot be removed using conventional desulfurizing agents such as zinc oxide, iron oxide, and ordinary activated carbon. Currently, organic sulfides are generally hydrogenated to form inorganic sulfides (H2S), which are then removed using the aforementioned desulfurizing agents. However, the hydrodesulfurization process requires high temperatures, consumes a significant amount of energy, and has a lengthy process flow.

[0004] Chinese invention patent CN 101954284A discloses a desulfurizing agent modified with copper oxide, iron oxide, aluminum oxide, cobalt oxide, nickel oxide, manganese oxide, and zinc oxide, which can be used to remove various sulfides under oxygen-rich conditions, generating elemental sulfur. Chinese invention patent CN 104549143A discloses a desulfurizing agent modified with aluminum oxide, nickel oxide, zinc oxide, and phosphorus pentoxide, which is claimed to have good removal effects on various sulfides under aerobic conditions. Chinese invention patent CN 101664689B discloses a desulfurizing agent prepared by mixing copper oxide or basic copper carbonate with pulverized coal to prepare modified activated carbon; however, its preparation process is relatively complicated. Due to the flammability of activated carbon, desulfurizing agents prepared using activated carbon as a carrier generally have poor regeneration effects. Chinese invention patent CN 115006989A discloses a desulfurizing agent using cerium oxide-modified ZSM-5 molecular sieve, which can remove methanethiol and ethanethiol at 400-450℃. However, this desulfurizing agent has a high operating temperature and absorbs organic sulfides after decomposition, making it unusable. Chinese invention patent CN 119793418A discloses a desulfurizing agent using a carrier (such as molecular sieve, alumina, silica gel, hydrotalcite, etc.) to support organic amines, which can remove various organic sulfides. However, this desulfurizing agent suffers from the loss of organic amines over time, preventing repeated use. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention provides an adsorption desulfurizing agent and its preparation method. The method operates under mild conditions, and the adsorption desulfurizing agent is reusable and suitable for removing various sulfides.

[0006] The specific technical solution is as follows:

[0007] An adsorption desulfurizing agent is a zirconium-based bimetallic organic framework compound, M-Zr-MOF, containing a transition metal M; wherein the transition metal M is selected from Cu. 2+ Fe 3+ Co 2+ Mn 2+ Ce 3+ The ligand is selected from terephthalic acid or trimesic acid with at least one organic amine substituent on the benzene ring.

[0008] Preferably, in the ligand, the organic amine is selected from those with C1~C2 carbon atoms. 20 At least one of primary amines, secondary amines, tertiary amines, and amides;

[0009] Preferably, in M-Zr-MOF, the molar ratio of transition metal M to Zr is (1~30):100.

[0010] A method for preparing an adsorbent desulfurizing agent includes the following steps: using an organic solvent as the reaction solvent, the adsorbent desulfurizing agent is obtained by reacting zirconium salt, transition metal M salt and ligand.

[0011] Furthermore, the molar ratio of the total amount of zirconium salt and transition metal M salt to the ligand is 1~5:10, wherein the molar ratio of zirconium salt to transition metal M salt is 3~100:1.

[0012] Preferably, the total amount of zirconium salt, transition metal M salt, and ligand is mixed with the organic solvent in a ratio of 1~5 mol:1000 mL.

[0013] Furthermore, the reaction temperature is 50~250℃, and the reaction time is 1~100h.

[0014] Furthermore, the zirconium salt is selected from at least one of soluble zirconium salts, preferably zirconium oxychloride, zirconium nitrate, zirconium sulfate, or zirconium acetate; the transition metal M salt is selected from at least one of soluble copper salt, soluble iron salt, soluble cobalt salt, soluble manganese salt, or soluble cerium salt, preferably nitrate, chloride, sulfate, or acetate.

[0015] Furthermore, the organic solvent is preferably anhydrous ethanol or dimethylformamide.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The present invention uses terephthalic acid or trimesic acid containing organic amine substituents as ligands to prepare metal-organic framework compounds, which can retain the adsorption effect of organic amines on sulfides and overcome the problem of easy loss of organic amines. Metal-organic framework compounds (MOFs) have well-developed pore structures and specific surface areas of up to several thousand square meters / g. All framework atoms can come into contact with the adsorbed molecules. At the same time, the present invention adds transition metal M to form heteroatom M-Zr-MOF materials during the synthesis of MOF materials, which can further improve the adsorption capacity of sulfides.

[0018] (2) Since sulfides are easily physically or chemically adsorbed at acidic or basic centers to achieve the purpose of removal, Zr in this invention has dual acid-base properties, thus having a good adsorption effect on sulfides; at the same time, zirconium-based metal-organic framework compounds have excellent temperature resistance and can maintain structural stability below 500℃. Detailed Implementation

[0019] The embodiments of the present invention will be described in further detail below with reference to the examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention. Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0020] Example 1

[0021] 100g of 2-ethylaminoterephthalic acid was weighed and dissolved in 200mL of dimethylformamide; 30g of zirconium oxychloride (ZrOCI2·8H2O) and 5g of copper nitrate (Cu(NO3)2·3H2O) were weighed and dissolved in 150mL of dimethylformamide; the Zr-Cu mixed salt solution was added to the 2-ethylaminoterephthalic acid solution at 70℃ with stirring, and the reaction was continued for 10h with stirring after the addition was completed. Then, the solution was filtered, washed with water, dried at 100℃ for 10h, and pressed into tablets to obtain the adsorbent desulfurizer; wherein, the molar ratio of Cu to Zr in the desulfurizer was 22:100.

[0022] Example 2

[0023] 100g of 2,5-dipropylaminoterephthalic acid was weighed and dissolved in 200mL of dimethylformamide; 30g of zirconium oxychloride (ZrOCI2·8H2O) and 10g of ferric nitrate (Fe(NO3)3·9H2O) were weighed and dissolved in 200mL of dimethylformamide; the Zr-Fe mixed salt solution was added to the 2,5-dipropylaminoterephthalic acid solution at 120℃ with stirring, and the reaction was continued for 15h after the addition was completed. Then, the mixture was filtered, washed with water, dried at 150℃ for 10h, and pressed into tablets to obtain the adsorbent desulfurizer; wherein, the molar ratio of Fe to Zr in the desulfurizer was 26:100.

[0024] Example 3

[0025] 110g of 2-ethylaminopyromellitic acid was weighed and dissolved in 200mL of dimethylformamide; 30g of zirconium oxychloride (ZrOCI2·8H2O) and 5g of copper nitrate (Cu(NO3)2·3H2O) were weighed and dissolved in 150mL of dimethylformamide; the Zr-Cu mixed salt solution was added to the 2-ethylaminopyromellitic acid solution at 100℃ with stirring, and the reaction was continued for 15h after the addition was completed. Then, the mixture was filtered, washed with water, dried at 120℃ for 10h, and pressed into tablets to obtain the adsorbent desulfurizer; wherein, the molar ratio of Cu to Zr in the desulfurizer was 22:100.

[0026] Example 4

[0027] 100g of 2-ethylaminoterephthalic acid was weighed and dissolved in 200mL of dimethylformamide; 30g of zirconium oxychloride (ZrOCI2·8H2O) and 3g of cobalt nitrate (Co(NO3)2·6H2O) were weighed and dissolved in 150mL of dimethylformamide; the Zr-Co mixed salt solution was added to the 2-ethylaminoterephthalic acid solution at 90℃ with stirring, and the reaction was continued for 20h after the addition was completed. Then, the mixture was filtered, washed with water, dried at 100℃ for 10h, and pressed into tablets to obtain the adsorbent desulfurizer; wherein, the molar ratio of Co to Zr in the desulfurizer was 11:100.

[0028] Example 5

[0029] 100g of 2-pentanaminoterephthalic acid was dissolved in 200mL of dimethylformamide; 30g of zirconium oxychloride (ZrOCI2·8H2O) and 7g of cerium nitrate (Ce(NO3)3·6H2O) were dissolved in 150mL of dimethylformamide; the Zr-Ce mixed salt solution was added to the 2-pentanaminoterephthalic acid solution at 120℃ with stirring, and the reaction was continued for 15h after the addition was completed. Then, the mixture was filtered, washed with water, dried at 150℃ for 10h, and pressed into tablets to obtain the adsorbent desulfurizer; the molar ratio of Ce to Zr in the desulfurizer was 17:100.

[0030] test

[0031] The adsorption desulfurizing agents prepared in Examples 1-5 of this invention were applied to the removal of sulfides from natural gas in a fixed-bed reactor with a desulfurizing agent loading of 100 mL and a gas space velocity of 1500 h⁻¹. -1 The desulfurization temperature was 40℃, and the concentrations were: H2S 110ppm, CS2 100ppm, CH3SH 120ppm, CH3SCH3 100ppm, with the remainder being natural gas. Gas was continuously supplied at the experimental temperature of 40℃ for 5 hours, and the sulfur content at the desulfurization reactor outlet was monitored. The results are shown in Table 1.

[0032] Table 1 Desulfurization effect of desulfurizing agents

[0033]

[0034] The above desulfurizing agent was continued to be circulated for a period of time. When the sulfide content in the tail gas exceeded 50% of the raw material gas content, the experiment was stopped. Then, the desulfurized desulfurizing agent was regenerated at 200℃ for 5 hours under a nitrogen atmosphere. Then, the desulfurization experiment was carried out under the same conditions as above. The gas was continuously circulated at an experimental temperature of 40℃ for 5 hours. The sulfur content at the outlet of the desulfurization reactor was monitored and the results are shown in Table 2.

[0035] Table 2 Desulfurization effect after desulfurizer regeneration

[0036]

[0037] The above experimental results show that the desulfurizing agent of the present invention has a high degree of desulfurization and purification, and can be regenerated.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adsorption desulfurizing agent, characterized in that, The adsorption desulfurizing agent is a zirconium-based bimetallic organic framework compound M-Zr-MOF containing the transition metal M; Among them, the transition metal M is selected from Cu. 2+ Fe 3+ Co 2+ Mn 2+ Ce 3+ The ligand is selected from terephthalic acid or trimesic acid with at least one organic amine substituent on the benzene ring.

2. The adsorption desulfurizing agent according to claim 1, characterized in that the ligand... In this context, organic amines are selected from those with carbon atoms ranging from C1 to C2. 20 At least one of primary amines, secondary amines, tertiary amines, and amides.

3. The adsorption desulfurizing agent according to claim 1, characterized in that, In M-Zr-MOF, the molar ratio of transition metal M to Zr is (1~30):

100.

4. The method for preparing the adsorption desulfurizing agent according to any one of claims 1 to 3, characterized in that, The process includes the following steps: using an organic solvent as the reaction solvent, the adsorption desulfurizer is obtained by reacting zirconium salt, transition metal M salt and ligand.

5. The preparation method according to claim 4, characterized in that, The total amount of zirconium salt and transition metal M salt is in a molar ratio of 1 to 5:10 to the ligand.

6. The preparation method according to claim 4, characterized in that, The total amount of zirconium salt, transition metal M salt, and ligands is mixed with the organic solvent in a ratio of 1~5 mol: 1000 mL.

7. The preparation method according to claim 4, characterized in that, The reaction temperature is 50~250℃, and the reaction time is 1~100h.

8. The preparation method according to claim 4, characterized in that, The zirconium salt is selected from at least one of soluble zirconium salts; the transition metal M salt is selected from at least one of soluble copper salt, soluble iron salt, soluble cobalt salt, soluble manganese salt, and soluble cerium salt.

9. The preparation method according to claim 4, characterized in that, The organic solvent is anhydrous ethanol or dimethylformamide.

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