A liquid-phase desulfurization agent of a schiff base metal complex and a preparation method and use thereof

Abstract

The present application relates to a kind of shiff base metal complex liquid desulfurizer and its preparation method and use, by amine and aldehyde condensation preparation the structure in the shiff base ligand containing C=N double bond, the lone pair electron of nitrogen atom on shiff base and metal atom are mutually cooperated to form shiff base metal complex, under the condition of oxygen or air as activating agent, the catalyst can be oxidized into inorganic sulfur with organic sulfur.The shiff base metal complex liquid desulfurizer of the present application is synthesized by low-cost raw material, without adding desulfurizer in the desulfurization process, solve the problems such as large amount of existing desulfurizer, need to be added continuously.At the same time, the desulfurizer is liquid desulfurizer, increase the contact area with organic sulfur gas, improve the desulfurization efficiency, the desulfurization rate of methyl mercaptan is higher than 99%.

Description

Technical Field

[0001] This invention belongs to the field of thiol and thioether removal technology, and particularly relates to a Schiff alkali metal complex desulfurizing agent, its preparation method and uses, etc. Background Technology

[0002] Natural gas, as a clean and efficient energy source, has gradually demonstrated its importance in recent years. However, the extracted feedstock gas contains organic sulfur compounds such as carbonyl sulfide (COS), thiols, and sulfides. These sulfur-containing compounds, including thiols and sulfides, are characterized by low odor thresholds, high volatility, high toxicity, and high corrosiveness. During processing, transportation, and storage, they can cause varying degrees of corrosion to equipment, and their combustion can also cause serious environmental damage. Therefore, to ensure the normal operation of downstream processes and guarantee product quality, it is essential to remove organic sulfur compounds from natural gas.

[0003] Gas desulfurization technologies include wet desulfurization, dry desulfurization, and semi-dry desulfurization. Wet catalytic oxidation is currently the main natural gas desulfurization process in my country's coking industry. During desulfurization, natural gas absorbs H2S from the coal gas using ammonia in the natural gas or added sodium carbonate as an alkali source under the action of a catalyst. Organic sulfur compounds are relatively stable in physicochemical properties and exist in molecular form in the solvent after absorption, making complete conversion difficult. Wet catalytic oxidation can oxidize the acidic gases released during solvent regeneration.

[0004] CN104560223B discloses a coal gas desulfurization device and method. First, SO2 in the coal gas is rapidly washed with a soluble alkaline washing solution such as Na2CO3 or MgO. Then, H2S is removed by wet catalytic oxidation using Na2CO3 or NH3H2O ​​as an alkali source, ultimately achieving desulfurization. This invention reduces system alkali and energy consumption, achieves good desulfurization effect, is low-cost and easy to implement, and can also recover finished sulfur, protecting the environment.

[0005] However, most existing desulfurization methods use single-molecule deodorization systems, which are effective at removing H2S, but more difficult to remove thiols and sulfides. Therefore, there is a need to develop efficient catalytic systems to achieve the catalytic oxidation and elimination of thiols and sulfides. Traditional industrial gas thiol removal technologies typically use metal oxides as catalysts, employing methods such as condensation, absorption, and adsorption. However, if the feed gas contains a large amount of hydrogen sulfide, additional hydrogen sulfide removal equipment is required, increasing equipment investment and operating costs.

[0006] CN101049551A discloses a high-sulfur-capacity catalytic oxidation desulfurizer and its preparation method, capable of simultaneously removing thiols, thioethers, and hydrogen sulfide from natural gas, associated petroleum gas, refinery gas, coal gas, and other industrial gases. Utilizing metal oxides and salts such as Al2O3, CaO, MgO, and CaSO4, combined with modifiers such as Na2CO3, NaHCO3, and NaNO3, and promoters such as phosphates, sulfonates, and oxygen-containing organic compounds, activated carbon is impregnated to prepare a desulfurizer for the catalytic oxidation removal of thiols, thioethers, and hydrogen sulfide. It can simultaneously catalytically oxidize and remove thiols, thioethers, and hydrogen sulfide; it has a high sulfur capacity, with a breakthrough sulfur capacity of over 14% and a working sulfur capacity of over 20% (g sulfur / g desulfurizer %). Furthermore, it has advantages such as a short process flow, low equipment investment, and environmental friendliness.

[0007] These catalysts are limited by the metal oxide loading, resulting in low sulfur capacity, typically between 2% and 8%. Furthermore, the desulfurizing agent preparation process requires calcination under a protective atmosphere, making the preparation method complex and costly. Organometallic complexes, including water-soluble ferrous salts, inorganic bases, organic complexes, and organic amines, possess excellent chemical stability and catalytic activity, making them applicable to various catalytic reactions, and are green and pollution-free.

[0008] CN107029537A discloses a complexed iron desulfurizing agent for desulfurization of liquefied petroleum gas. Its components include water-soluble ferrous salt, inorganic alkali, water-soluble manganese salt, organic complexing agent, and water, as well as piperazine and organic solvent. This desulfurizing agent can simultaneously remove hydrogen sulfide and mercaptans. However, its complex composition requires the addition of organic complexing agent and inorganic alkali, increasing costs. Furthermore, the ferric iron is gradually consumed during desulfurization, necessitating continuous replenishment of the desulfurization solution.

[0009] CN102633842A discloses a method for preparing a bimetallic reactive center ionic liquid desulfurizer and its application. The bimetallic reactive center ionic liquid is composed of organically complexed Co or Fe cations and complexed Fe anions. It is generated through the reaction of organometallic complexes with functional groups such as -CH2Cl and -SO2Cl with Fe-based ionic liquids with functional groups such as -NH and -OH. The organometallic complexes are Schiff base Co or Fe complexes and phthalocyanine Co or Fe complexes. These bimetallic reactive center ionic liquid desulfurizers are particularly suitable for removing organic sulfur compounds such as thiols, thioethers, and thiophenes, as well as inorganic H2S. However, the preparation process of the ionic liquid desulfurizer is complex and lengthy.

[0010] Salicylic aldehyde is commonly used as a ligand for the synthesis of Schiff bases, but it has poor solubility in water and cannot fully contact organic sulfur gases during desulfurization, resulting in poor desulfurization efficiency. Introducing sulfonate groups into the salicylic aldehyde structure can prepare sulfonated salicylic aldehyde, which has excellent water solubility.

[0011] Wu Xuemei et al. [Wu Xuemei, Dong Jianyuan, Yang Fan, et al. Synthesis, characterization and catalytic properties of Cu-containing complexes of sulfonated salicylaldehyde acetal aniline [J]. Chemical World, 2007, 48(8): 456-459.] disclosed the synthesis, characterization and catalytic properties of Cu-containing complexes of sulfonated salicylaldehyde acetal aniline. They synthesized a copper-containing complex with sulfonated salicylaldehyde acetal aniline as a ligand and characterized it by elemental analysis using infrared spectroscopy. The catalytic activity of this compound against the oxidation of ascorbic acid in air and its catalytic performance in the presence of cucurbitacin were investigated by UV-Vis spectroscopy. The results showed that the complex exhibited good catalytic performance against the oxidation of ascorbic acid in air, and the catalytic performance was improved upon the addition of cucurbitacin.

[0012] Therefore, synthesizing efficient, low-volume, and easy-to-operate liquid-phase desulfurizing agents using simple preparation methods and low-cost raw materials is an urgent technical problem to be solved. Summary of the Invention

[0013] To address the above problems, this invention synthesizes a Schiff alkali metal complex liquid-phase desulfurizer and applies it to gas desulfurization. By removing organic compounds such as thiols and thioethers from the gas, it optimizes and protects downstream production processes. Therefore, the invention of a Schiff alkali metal complex desulfurizer is of great significance in this field.

[0014] This invention provides a Schiff alkali metal complex liquid-phase desulfurizer, wherein the structural formula of the Schiff alkali metal complex in the liquid-phase desulfurizer is as follows: Where R1 is -CH2CH2- or One of them, M is one of Fe, Co, Cu, and Mn.

[0015] The Schiff alkali metal complex liquid-phase desulfurizer of this invention, in its infrared spectrum, shows that the Schiff alkali metal complex (M(Salen)) in the liquid-phase desulfurizer is at 3449.2 cm⁻¹. -1 ±0.1cm -1 1643.1cm -1 ±0.1cm -1 1113cm -1 ±0.1cm -1 420.6cm -1 ±0.1cm -1 At 470.1 cm⁻¹ ± 0.1 cm⁻¹, -OH, C=N, and SO₄⁻ appear respectively. 2-Characteristic peaks of Co-N and Co-O; an absorption band appears in the Schiff base metal complex at 350-370 nm in the ultraviolet spectrum; in thermogravimetric analysis, the mass reduction of the Schiff base metal complex is less than 2% when heated to 200 °C.

[0016] The preparation method of the Schiff alkali metal complex liquid-phase desulfurizer of the present invention includes the following steps:

[0017] Step 1: Under stirring conditions, concentrated sulfuric acid is added dropwise to salicylaldehyde, and the mixture is heated to the reaction temperature to carry out the reaction. After the reaction, a mixed solution A is obtained. Mixed solution A is poured into ice water, and anhydrous sodium carbonate is added. The mixture is stirred to neutralize the remaining concentrated sulfuric acid. The mixed solution A after neutralization of concentrated sulfuric acid is filtered under reduced pressure to obtain a light pink precipitate B. The light pink precipitate B is dissolved in hot water and recrystallized until the crystals are completely precipitated. The crystals are filtered to obtain crystal C. Crystal C is washed with acetone until it turns white, and the washed crystal C is dried under vacuum to obtain sulfosalicylic aldehyde.

[0018] Step 2: Under a nitrogen atmosphere, the sulfosalicylic aldehyde is added to ethanol, heated to reflux, and dispersed evenly to obtain a mixed solution D; ethylenediamine or o-phenylenediamine is dissolved in ethanol to obtain a mixed solution E; mixed solution E is placed in a constant pressure dropping funnel and added dropwise to mixed solution D to react, obtaining a mixed solution F; mixed solution F is refrigerated at low temperature, and the refrigerated mixed solution F is filtered to obtain yellow crystals G; yellow crystals G are washed 3-5 times with low temperature ethanol solution, and vacuum dried to obtain Schiff base ligands;

[0019] Step 3: Under a nitrogen atmosphere, the Schiff base ligand is added to ethanol, heated to reflux, and dispersed evenly to obtain a mixed solution H; the transition metal salt is dissolved in ethanol to obtain a mixed solution I; mixed solution I is placed in a constant pressure dropping funnel and added dropwise to mixed solution H to react, obtaining a mixed solution J; mixed solution J is refrigerated at low temperature, and the refrigerated mixed solution J is filtered to obtain crystal K; crystal K is washed with ethanol 3-5 times, filtered, and vacuum dried to obtain the Schiff base metal complex;

[0020] Step 4: Add the Schiff base metal complex to a solvent and stir to dissolve it at room temperature to obtain a Schiff base metal complex liquid-phase desulfurizer.

[0021] Furthermore, the synthetic route for sulfosalicylic aldehyde in step 1 is as follows:

[0022] .

[0023] Furthermore, the stirring speed in step 1 is 80-120 r / min.

[0024] Furthermore, in step 1, the mass ratio of salicylaldehyde to concentrated sulfuric acid is (10:1)-(18:1).

[0025] Furthermore, in step 1, the rate at which concentrated sulfuric acid is added is 60-100 drops / min.

[0026] Furthermore, in step 1, the reaction temperature is 30-50℃ and the reaction time is 12-24h.

[0027] Furthermore, the temperature of the ice water in step 1 is -5 to 5°C.

[0028] Furthermore, in step 1, the volume ratio of mixed solution A to ice water is (1:4) - (1:1).

[0029] Furthermore, in step 1, the mass-to-volume ratio of anhydrous sodium carbonate to concentrated sulfuric acid is 1-2 g / mL.

[0030] Furthermore, in step 1, the mixing speed is 50-150 r / min, and the mixing time is 120-180 min.

[0031] Furthermore, in step 1, the temperature of the hot water is 50-80℃, and the volume ratio of the hot water to the mixed solution A is (1:1)-(2:1).

[0032] Furthermore, the recrystallization temperature in step 1 is 0-5℃.

[0033] Furthermore, in step 1, the vacuum drying temperature is 50-200℃, the vacuum drying time is 24-72h, and the vacuum degree of vacuum drying is -0.1Mpa.

[0034] Furthermore, the synthetic route for the Schiff base ligand in step 2 is as follows:

[0035] Where R1 is -CH2CH2- or One of them.

[0036] Furthermore, in step 2, the mass-to-volume ratio of sulfosalicylic aldehyde to ethanol in the mixed solution D is 0.01-0.05 g / mL.

[0037] Furthermore, in step 2, the reflux temperature is 50-100℃, and the reflux time is 0.1-1h.

[0038] Furthermore, in step 2, the concentration of ethylenediamine or o-phenylenediamine in the mixed solution E is 0.1-0.5 mol / L.

[0039] Furthermore, in step 2, the volume ratio of mixed solution D to mixed solution E is (10:1) - (10:5).

[0040] Furthermore, the dripping rate in step 2 is 80-100 drops / min.

[0041] Furthermore, the reaction temperature in step 2 is 50-80℃, and the reaction time is 1-5h.

[0042] Furthermore, in step 2, the refrigeration temperature is 0-5℃, and the refrigeration time is 1-10 hours.

[0043] Furthermore, in step 2, the temperature of the low-temperature ethanol is -10 to 5°C, and the volume ratio of the low-temperature ethanol to the mixed solution F is (1:3) to (1:1).

[0044] Furthermore, in step 2, the vacuum drying temperature is 50-200℃, the vacuum drying time is 24-72h, and the vacuum degree of vacuum drying is -0.1Mpa.

[0045] Furthermore, in step 3, the Schiff base ligand coordinates with the metal ion to form a Schiff base metal complex.

[0046] Furthermore, the reaction synthesis route for the Schiff base metal complex in step 3 is as follows:

[0047] Where R1 is -CH2CH2- or One of them, M is one of Fe, Co, Cu, Mn, and n in Mn+ is greater than or equal to 1.

[0048] Furthermore, in step 3, the concentration of the Schiff base ligand in the mixed solution H is 0.10-0.15 mol / L.

[0049] Furthermore, in step 3, the reflux temperature is 50-100℃, and the reflux time is 2.5-3.5h.

[0050] Furthermore, in step 3, the concentration of the transition metal salt in the mixed solution I is 0.2-0.5 mol / L.

[0051] Furthermore, in step 3, the volume ratio of mixed solution H to mixed solution I is (1.3:1) - (2:1).

[0052] Furthermore, the dripping rate in step 3 is 80-100 drops / min.

[0053] Furthermore, the reaction temperature in step 3 is 100-500℃, and the reaction time is 1-10h.

[0054] Furthermore, in step 3, the refrigeration temperature is 0-5℃, and the refrigeration time is 1-12 hours.

[0055] Furthermore, in step 3, the vacuum drying temperature is 50-200℃, the vacuum drying time is 24-72h, and the vacuum degree of vacuum drying is -0.1Mpa.

[0056] Furthermore, in step 3, the transition metal salt is one of ferric acetate, cobalt acetate, copper acetate, manganese acetate, ferric chloride, and copper chloride.

[0057] Furthermore, in step 3, the Schiff base ligand is a compound containing a C=N double bond in its structure. These organic compounds are formed by the condensation of amines and aldehydes. By changing the substituents, donor atoms, and their positions, many chain-like, cyclic ligands with different properties and structures can be synthesized. Therefore, the lone pair electrons of the nitrogen atom on the Schiff base ligand interact with the metal atom to form a Schiff base metal complex. This complex can undergo axial coordination with oxygen in an oxygen-rich state, activating molecular oxygen and thus altering the kinetic inertness of molecular oxygen, resulting in excellent catalytic oxidation performance.

[0058] Furthermore, in step 4, the concentration of the Schiff alkali metal complex in the liquid-phase desulfurizing agent is 100-10000 mg / L.

[0059] Furthermore, the solvent in step 4 is deionized water.

[0060] Furthermore, in step 4, the stirring speed is 80-120 r / min, and the stirring time is 0.5-1 h.

[0061] The application of the Schiff alkali metal complex liquid-phase desulfurizer described in this invention is for gas desulfurization, specifically including the following desulfurization steps:

[0062] Step 1: Mix the sulfur-containing raw material gas and the dilution gas to obtain a mixed gas;

[0063] Step 2: Inject the Schiff alkali metal complex liquid phase desulfurizer into the reactor, heat it to the reaction temperature, and then introduce the mixed gas into the reactor for desulfurization.

[0064] Furthermore, the sulfur-containing raw material gas in step 1 contains nitrogen and organic sulfur gas, and the nitrogen is a carrier gas.

[0065] Furthermore, the organic sulfur gas in step 1 is one of methanethiol (CH3-SH) or dimethyl sulfide (CH3-S-CH3).

[0066] Further, in step 1, the volume ratio of sulfur-containing raw material gas to dilution gas is (1:8)-(8:1).

[0067] Furthermore, the dilution gas in step 1 is either oxygen or air.

[0068] Furthermore, in step 2, the mixed gas is continuously bubbled into a reactor containing a Schiff alkali metal complex liquid-phase desulfurizer, and the reactor is a bubbling reactor.

[0069] Furthermore, in step 2, the reaction temperature is 20-80℃ and the reaction time is 2-3 hours.

[0070] Furthermore, the desulfurization mechanism of the Schiff alkali metal complex liquid-phase desulfurizer in step 2 is as follows:

[0071] Mechanism of axial coordination with oxygen under oxygen-enriched conditions:

[0072] M(Salen) + O2 M(Salen)-[O2]

[0073] M(Salen)-[O2]+M(Salen) M(Salen)-[O2]-M(Salen);

[0074] Mechanism of demethyl mercaptan removal process of Schiff alkali metal complex liquid-phase desulfurizer:

[0075] M(Salen)-[O2]-M(Salen)+CH3SH→CH3SO→CH3SO2→H2SO4;

[0076] Mechanism of demethyl sulfide removal process of Schiff alkali metal complex liquid-phase desulfurizer:

[0077] M(Salen)-[O2]-M(Salen)+CH3-S-CH3→CH3-SO-CH3→CH3-SO2-CH3→H2SO4.

[0078] The beneficial effects of this invention are:

[0079] 1. The present invention prepares a liquid-phase desulfurizer by coordinating Schiff bases with metal ions, wherein the structure of the Schiff base metal complex in the liquid-phase desulfurizer is stable.

[0080] 2. This invention introduces sulfonyl groups into the Schiff alkali metal complex liquid-phase desulfurizer, which increases the water solubility of the Schiff alkali metal complex liquid-phase desulfurizer and improves its solubility.

[0081] 3. The solvent of the Schiff alkali metal complex liquid phase desulfurizer described in this invention is clean and readily available deionized water, which is low in cost and non-toxic and harmless.

[0082] 4. The Schiff alkali metal complex liquid phase desulfurizer described in this invention requires a small amount of desulfurization agent and does not require continuous large-scale addition of desulfurizer, which greatly reduces costs.

[0083] 5. The Schiff alkali metal complex liquid-phase desulfurizer described in this invention can achieve 100% removal efficiency of methanethiol under the condition of air as an activator, and also has a certain removal efficiency of dimethyl sulfide.

[0084] 6. The Schiff alkali metal complex liquid phase desulfurizer described in this invention can effectively convert organic sulfur into SO42-, thus achieving the goal of converting organic sulfur into inorganic sulfides;

[0085] 7. The Schiff alkali metal complex liquid-phase desulfurizer described in this invention is a liquid desulfurizer, which can increase the contact area with the gas and improve the desulfurization efficiency when used in the gas desulfurization process;

[0086] 8. The Schiff alkali metal complex liquid-phase desulfurizer described in this invention is a liquid desulfurizer, which is not only suitable for the desulfurization of methanethiol and dimethyl sulfide, but also suitable for the removal of thiols and thioether organic sulfur. It has a wide range of applications and is industrially applicable. Attached Figure Description

[0087] Figure 1 The infrared spectrum of the Schiff base metal complex in the liquid-phase desulfurizing agent of the Schiff base metal complex in Example 1 of the present invention is shown.

[0088] Figure 2 The image shows the ultraviolet spectrum of the Schiff base metal complex in the liquid-phase desulfurizing agent of the Schiff base metal complex in Example 1 of this invention.

[0089] Figure 3 Thermogravimetric analysis diagram of the Schiff alkali metal complex in the liquid-phase desulfurizing agent of the Schiff alkali metal complex in Example 1 of the present invention;

[0090] Figure 4 This describes the presence of various anions in the solution of the Schiff alkali metal complex liquid-phase desulfurizer before desulfurization in Example 1 of the present invention.

[0091] Figure 5 This describes the presence of various anions in the solution after desulfurization by the Schiff alkali metal complex liquid-phase desulfurizing agent in Example 1 of the present invention.

[0092] Figure 6 Thermogravimetric analysis diagram of Schiff alkali metal complex in liquid-phase desulfurizer of Schiff alkali metal complex in Example 3 of the present invention;

[0093] Figure 7The graphs show the changes in the demethyl mercaptan removal efficiency of the Schiff alkali metal complex liquid-phase desulfurizers in Examples 1, 2, and 3 of this invention as a function of desulfurization time.

[0094] Figure 8 This describes the presence of various anions in the solution after desulfurization by the Schiff alkali metal complex liquid-phase desulfurizing agent in Example 4 of the present invention.

[0095] Figure 9 The graphs show the changes in the demethyl sulfide removal efficiency of the Schiff alkali metal complex liquid-phase desulfurizer in Examples 4 and 5 of this invention as a function of desulfurization time.

[0096] Figure 10 This is a graph showing the change in the desulfurization efficiency of the desulfurizing agent for methanethiol removal as a function of desulfurization time in Comparative Example 1 of this invention.

[0097] Figure 11 This is a graph showing the change in the desulfurization efficiency of the desulfurizing agent for methyl sulfide in Comparative Example 2 of the present invention as a function of desulfurization time.

[0098] Figure 12 This is a diagram of a desulfurization device for gas desulfurization using the Schiff alkali metal complex liquid-phase desulfurizer of the present invention;

[0099] The labels in the diagram are as follows: 1. Sulfur-containing raw material gas cylinder; 2. Dilution gas cylinder; 3. Sulfur-containing raw material gas flow meter; 4. Dilution gas flow meter; 5. Mixed gas cylinder; 6. Mixed gas flow meter; 7. Desulfurizing agent sampling port; 8. Bubbling reactor; 9. Gas distributor; 10. Constant temperature water bath; 11. Tail gas absorption bottle; 12. Gas chromatograph. Detailed Implementation

[0100] The invention will be described in detail below with reference to the embodiments:

[0101] This invention provides a Schiff alkali metal complex liquid-phase desulfurizer, its preparation method, and its uses. The raw materials are inexpensive, the resulting liquid-phase desulfurizer requires a small amount and does not need to be added continuously on a large scale. It has high desulfurization efficiency, simplifies the operation technology, saves costs, and improves desulfurization efficiency.

[0102] Example 1

[0103] The preparation method of the Schiff alkali metal complex liquid-phase desulfurizer described in this embodiment includes the following steps:

[0104] Step 1: Under stirring at 100 rpm, 50 mL of concentrated sulfuric acid was added dropwise at a rate of 80 drops / min to a three-necked flask containing 5.8 g of salicylaldehyde, and the mixture was heated to 35 °C and reacted for 18 h to obtain 50 mL of mixed solution A. 50 mL of mixed solution A was poured into 200 mL of ice water, and 50 g of anhydrous sodium carbonate was added. The mixture was stirred at 100 rpm for 150 min to neutralize the remaining concentrated sulfuric acid. Mixed solution A after neutralization was filtered under reduced pressure to obtain a light pink precipitate B. The light pink precipitate B was dissolved in 50 mL of hot water at 80 °C and recrystallized at 0 °C until the crystals were completely precipitated. The crystals were filtered to obtain crystal C. Crystal C was washed with acetone until it turned white. The washed crystal C was dried under vacuum at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain sulfosalicylic acid.

[0105] Step 2: Under a nitrogen atmosphere, 0.02 mol of sulfosalicylic aldehyde obtained in Step 1 and 100 mL of ethanol were added to a three-necked flask and heated under reflux at 68 °C for 0.5 h to disperse the solution evenly, resulting in mixed solution D. 0.01 mol of ethylenediamine was dissolved in 30 mL of ethanol to obtain mixed solution E. Mixed solution E was placed in a constant pressure dropping funnel and added dropwise at a rate of 80 drops / min to the three-necked flask containing mixed solution D. The mixture was reacted at 68 °C for 2 h to obtain mixed solution F. Mixed solution F was placed under 0 °C for 10 h and filtered to obtain yellow crystals G. Yellow crystals G were washed 3-5 times with 150 mL of 0 °C low-temperature ethanol solution. The washed crystals G were then vacuum dried at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain the Schiff base ligand.

[0106] Step 3: Under a nitrogen atmosphere, add 0.01 mol of the Schiff base ligand obtained in Step 2 and 80 mL of ethanol to a three-necked flask, heat and reflux at 68 °C for 3 h to disperse evenly, and obtain mixed solution H; dissolve 0.02 mol of cobalt acetate in 50 mL of ethanol to obtain mixed solution I; place mixed solution I in a constant pressure dropping funnel and add it dropwise at a rate of 80 drops / min to the three-necked flask containing mixed solution H, react at 100 °C for 3 h to obtain mixed solution J; place mixed solution J in a low temperature refrigeration condition at 0 °C, filter the refrigerated mixed solution J to obtain crystal K, wash crystal K with ethanol 3-5 times, filter the washed crystal K, and vacuum dry at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain the Schiff base metal complex;

[0107] Step 4: Add 0.5g of the Schiff alkali metal complex obtained in Step 3 to 1000mL of deionized water and stir to dissolve at room temperature to obtain the Schiff alkali metal complex liquid phase desulfurizer.

[0108] like Figure 1The image shown is the infrared spectrum of the Schiff alkali metal complex in the liquid-phase desulfurizing agent of this embodiment, where the horizontal axis is Wavenumbers / cm. -1 The vertical axis represents wavenumber, and the vertical axis represents transmittance (T / %). In the figure, the absorption peak of C=N in the Schiff base metal complex at 1643 cm⁻¹ exhibits a red shift. This is due to the interaction between the Schiff base ligand and Co. 2+ Caused by coordination.

[0109] like Figure 2 The image shows the ultraviolet spectrum of the Schiff alkali metal complex in the liquid-phase desulfurizer of this embodiment. The horizontal axis represents wavelength (Wavelength / nm), and the vertical axis represents absorbance. The absorption band at 350-370 nm represents the absorption of the metal ion Co. 2+ It is generated by a charge transition between the ligand and the Schiff base.

[0110] like Figure 3 The figure shows the thermogravimetric analysis of the Schiff alkali metal complex in the liquid-phase desulfurizer of this embodiment. The horizontal axis represents temperature (°C) and the vertical axis represents mass (%). In the figure, the mass decrease of the Schiff alkali metal complex is less than 2% when the temperature is increased to 200°C, which indicates that the Schiff alkali metal complex liquid-phase desulfurizer in this embodiment has good thermal stability.

[0111] The application of the Schiff alkali metal complex liquid-phase desulfurizer described in this embodiment is for gas desulfurization, such as... Figure 12 The diagram shown is of a desulfurization device for gas desulfurization using Schiff alkali metal complex liquid-phase desulfurizer in this embodiment, including the following steps:

[0112] Step 1: Open the sulfur-containing raw material gas cylinder 1 containing 200 ppm methanethiol and the dilution gas cylinder 2. Control the flow rate of the sulfur-containing raw material gas flow meter 3 to 60 mL / min and the flow rate of the dilution gas flow meter 4 to 500 mL / min. Introduce the mixed gas cylinder 5 and mix evenly to obtain a mixed gas.

[0113] Step 2: Inject 30 mL of Schiff alkali metal complex liquid phase desulfurizer into the bubbling reactor 8, and heat the bubbling reactor 8 with a constant temperature water bath 10 to 30°C. Then, continuously introduce the mixed gas into the bubbling reactor 8 containing the Schiff alkali metal complex liquid phase desulfurizer through the gas distributor 9 at a flow rate of 30 mL / min using the mixed gas flow meter 6. The desulfurization time is 3 hours.

[0114] Step 3: Take the desulfurized Schiff alkali metal complex liquid-phase desulfurizer from the sampling port 7 of the bubbling reactor 8, and analyze the presence of anions. Compare it with the Schiff alkali metal complex liquid-phase desulfurizer before desulfurization. Figure 4 The image shows the presence of various anions in the solution of the Schiff alkali metal complex liquid-phase desulfurizer before desulfurization in this embodiment. Figure 5 This figure shows the presence of various anions in the solution after desulfurization by the Schiff alkali metal complex liquid-phase desulfurizing agent in this embodiment. The horizontal axis represents time / min, and the vertical axis represents ionic conductivity (μs / cm). By comparison, the SO4 content in the solution after desulfurization is significantly higher. 2- The significant increase indicates that the desulfurizing agent effectively converts methanethiol into SO4. 2- ;

[0115] Step 4: Take the desulfurized sulfur-containing raw material gas from the gas outlet at the top of the bubbling reactor 8, and use a gas chromatograph 12 to periodically detect the content of organic sulfur in the sulfur-containing raw material gas. The test results show that the concentration of methanethiol in the sulfur-containing raw material gas after dilution with dilution gas is 30 ppm, and the methanethiol content in the tail gas is 0 ppm. The desulfurization effect is 100%. The desulfurized gas is passed into the tail gas absorption bottle 11 for recovery.

[0116] In this embodiment, the sulfur-containing raw material gas cylinder 1 contains 200 ppm of methanethiol and nitrogen, with the nitrogen serving as the carrier gas. The dilution gas is oxygen. The bubbling reactor 8 has an effective height of 30 cm, an inner diameter of 2 cm, and an outer diameter of 4 cm. The gas distributor 9 has a G3 glass frit core. The gas chromatograph 12 is a GC-7820. The solution in the tail gas absorption bottle 11 is 20% industrial-grade sodium hypochlorite.

[0117] Example 2

[0118] The preparation method of the Schiff alkali metal complex liquid-phase desulfurizer described in this embodiment includes the following steps:

[0119] Step 1: Under stirring at 100 rpm, 50 mL of concentrated sulfuric acid was added dropwise at a rate of 80 drops / min to a three-necked flask containing 5.8 g of salicylaldehyde, and the mixture was heated to 35 °C and reacted for 18 h to obtain 50 mL of mixed solution A. 50 mL of mixed solution A was poured into 200 mL of ice water, and 50 g of anhydrous sodium carbonate was added. The mixture was stirred at 100 rpm for 150 min to neutralize the remaining concentrated sulfuric acid. Mixed solution A after neutralization was filtered under reduced pressure to obtain a light pink precipitate B. The light pink precipitate B was dissolved in 50 mL of hot water at 80 °C and recrystallized at 0 °C until the crystals were completely precipitated. The crystals were filtered to obtain crystal C. Crystal C was washed with acetone until it turned white. The washed crystal C was dried under vacuum at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain sulfosalicylic acid.

[0120] Step 2: Under a nitrogen atmosphere, 0.02 mol of sulfosalicylic aldehyde obtained in Step 1 and 100 mL of ethanol were added to a three-necked flask and heated under reflux at 68 °C for 0.5 h to disperse the solution evenly, resulting in mixed solution D. 0.01 mol of ethylenediamine was dissolved in 30 mL of ethanol to obtain mixed solution E. Mixed solution E was placed in a constant pressure dropping funnel and added dropwise at a rate of 80 drops / min to the three-necked flask containing mixed solution D. The mixture was reacted at 68 °C for 2 h to obtain mixed solution F. Mixed solution F was placed under 0 °C for 10 h and filtered to obtain yellow crystals G. Yellow crystals G were washed 3-5 times with 150 mL of 0 °C low-temperature ethanol solution. The washed crystals G were then vacuum dried at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain the Schiff base ligand.

[0121] Step 3: Under a nitrogen atmosphere, add 0.01 mol of the Schiff base ligand obtained in Step 2 and 80 mL of ethanol to a three-necked flask, heat and reflux at 68 °C for 3 h to disperse evenly, and obtain mixed solution H; dissolve 0.02 mol of cobalt acetate in 50 mL of ethanol to obtain mixed solution I; place mixed solution I in a constant pressure dropping funnel and add it dropwise at a rate of 80 drops / min to the three-necked flask containing mixed solution H, react at 100 °C for 3 h to obtain mixed solution J; place mixed solution J in a low temperature refrigeration condition at 0 °C, filter the refrigerated mixed solution J to obtain crystal K, wash crystal K with ethanol 3-5 times, filter the washed crystal K, and vacuum dry at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain the Schiff base metal complex;

[0122] Step 4: Add 0.5g of the Schiff alkali metal complex obtained in Step 3 to 1000mL of deionized water and stir to dissolve at room temperature to obtain the Schiff alkali metal complex liquid phase desulfurizer.

[0123] The application of the Schiff alkali metal complex liquid-phase desulfurizer described in this embodiment is for gas desulfurization, such as... Figure 12 The diagram shown is of a desulfurization device for gas desulfurization using Schiff alkali metal complex liquid-phase desulfurizer in this embodiment, including the following steps:

[0124] Step 1: Open the sulfur-containing raw material gas cylinder 1 containing 200 ppm methanethiol and the dilution gas cylinder 2. Control the flow rate of the sulfur-containing raw material gas flow meter 3 to 300 mL / min and the flow rate of the dilution gas flow meter 4 to 140 mL / min. Introduce the mixed gas cylinder 5 and mix evenly to obtain a mixed gas.

[0125] Step 2: Inject 30 mL of Schiff alkali metal complex liquid phase desulfurizer into the bubbling reactor 8, and heat the bubbling reactor 8 with a constant temperature water bath 10 to 30°C. Then, continuously introduce the mixed gas into the bubbling reactor 8 containing the Schiff alkali metal complex liquid phase desulfurizer through the gas distributor 9 at a flow rate of 30 mL / min using the mixed gas flow meter 6. The desulfurization time is 3 hours.

[0126] Step 3: Take the desulfurized sulfur-containing raw material gas from the gas outlet at the top of the bubbling reactor 8, and use a gas chromatograph 12 to periodically detect the content of organic sulfur in the sulfur-containing raw material gas. The test results show that the concentration of methanethiol in the sulfur-containing raw material gas after dilution with dilution gas is 75 ppm, and the methanethiol content in the tail gas is 0 ppm. The desulfurization effect is 100%. The desulfurized gas is passed into the tail gas absorption bottle 11 for recovery.

[0127] In this embodiment, the sulfur-containing raw material gas cylinder 1 contains 200 ppm of methanethiol and nitrogen, with the nitrogen serving as the carrier gas. The dilution gas is oxygen. The bubbling reactor 8 has an effective height of 30 cm, an inner diameter of 2 cm, and an outer diameter of 4 cm. The gas distributor 9 has a G3 glass frit core. The gas chromatograph 12 is a GC-7820. The solution in the tail gas absorption bottle 11 is 20% industrial-grade sodium hypochlorite.

[0128] Example 3

[0129] The preparation method of the Schiff alkali metal complex liquid-phase desulfurizer described in this embodiment includes the following steps:

[0130] Step 1: Under stirring at 100 rpm, 50 mL of concentrated sulfuric acid was added dropwise at a rate of 80 drops / min to a three-necked flask containing 5.8 g of salicylaldehyde, and the mixture was heated to 35 °C and reacted for 18 h to obtain 50 mL of mixed solution A. 50 mL of mixed solution A was poured into 200 mL of ice water, and 50 g of anhydrous sodium carbonate was added. The mixture was stirred at 100 rpm for 150 min to neutralize the remaining concentrated sulfuric acid. Mixed solution A after neutralization was filtered under reduced pressure to obtain a light pink precipitate B. The light pink precipitate B was dissolved in 50 mL of hot water at 80 °C and recrystallized at 0 °C until the crystals were completely precipitated. The crystals were filtered to obtain crystal C. Crystal C was washed with acetone until it turned white. The washed crystal C was dried under vacuum at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain sulfosalicylic acid.

[0131] Step 2: Under a nitrogen atmosphere, 0.02 mol of sulfosalicylic aldehyde obtained in Step 1 and 100 mL of ethanol were added to a three-necked flask and heated under reflux at 68 °C for 0.5 h to disperse the solution evenly, resulting in mixed solution D. 0.01 mol of ethylenediamine was dissolved in 30 mL of ethanol to obtain mixed solution E. Mixed solution E was placed in a constant pressure dropping funnel and added dropwise at a rate of 80 drops / min to the three-necked flask containing mixed solution D. The mixture was reacted at 68 °C for 2 h to obtain mixed solution F. Mixed solution F was placed under 0 °C for 10 h and filtered to obtain yellow crystals G. Yellow crystals G were washed 3-5 times with 150 mL of 0 °C low-temperature ethanol solution. The washed crystals G were then vacuum dried at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain the Schiff base ligand.

[0132] Step 3: Under a nitrogen atmosphere, add 0.01 mol of the Schiff base ligand obtained in Step 2 and 80 mL of ethanol to a three-necked flask, heat and reflux at 68 °C for 3 h to disperse evenly, and obtain mixed solution H; dissolve 0.02 mol of ferric acetate in 50 mL of ethanol to obtain mixed solution I; place mixed solution I in a constant pressure dropping funnel and add it dropwise at a rate of 80 drops / min to the three-necked flask containing mixed solution H, react at 100 °C for 3 h to obtain mixed solution J; place mixed solution J in a low temperature refrigeration condition at 0 °C, filter the refrigerated mixed solution J to obtain crystal K, wash crystal K with ethanol 3-5 times, filter the washed crystal K, and vacuum dry at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain the Schiff base metal complex;

[0133] Step 4: Add 0.5g of the Schiff alkali metal complex obtained in Step 3 to 1000mL of deionized water and stir to dissolve at room temperature to obtain the Schiff alkali metal complex liquid phase desulfurizer.

[0134] like Figure 6 The figure shows the thermogravimetric analysis of the Schiff alkali metal complex in the liquid-phase desulfurizer of the Schiff alkali metal complex in this embodiment. The horizontal axis represents temperature (°C) and the vertical axis represents mass (%). In the figure, the mass reduction of the Schiff alkali metal complex is less than 2% when the temperature is increased to 200°C, indicating that the Schiff alkali metal complex liquid-phase desulfurizer in this embodiment has high thermal stability.

[0135] The application of the Schiff alkali metal complex liquid-phase desulfurizer described in this embodiment is for gas desulfurization, such as... Figure 12 The diagram shown is of a desulfurization device for gas desulfurization using Schiff alkali metal complex liquid-phase desulfurizer in this embodiment, including the following steps:

[0136] Step 1: Open the sulfur-containing raw material gas cylinder 1 containing 200 ppm methanethiol and the dilution gas cylinder 2. Control the flow rate of the sulfur-containing raw material gas flow meter 3 to 500 mL / min and the flow rate of the dilution gas flow meter 4 to 60 mL / min. Introduce the mixed gas cylinder 5 and mix evenly to obtain a mixed gas.

[0137] Step 2: Inject 30 mL of Schiff alkali metal complex liquid phase desulfurizer into the bubbling reactor 8, and heat the bubbling reactor 8 with a constant temperature water bath 10 to 30°C. Then, continuously introduce the mixed gas into the bubbling reactor 8 containing the Schiff alkali metal complex liquid phase desulfurizer through the gas distributor 9 at a flow rate of 30 mL / min using the mixed gas flow meter 6. The desulfurization time is 3 hours.

[0138] Step 3: Take the desulfurized sulfur-containing raw material gas from the gas outlet at the top of the bubbling reactor 8, and use a gas chromatograph 12 to periodically detect the content of organic sulfur in the sulfur-containing raw material gas. The test results show that the concentration of methanethiol in the sulfur-containing raw material gas after dilution with dilution gas is 100 ppm, and the methanethiol content in the tail gas is 0 ppm. The desulfurization effect is 100%. The desulfurized gas is passed into the tail gas absorption bottle 11 for recovery.

[0139] In this embodiment, the sulfur-containing raw material gas cylinder 1 contains 200 ppm of methanethiol and nitrogen, with the nitrogen serving as the carrier gas. The dilution gas is oxygen. The bubbling reactor 8 has an effective height of 30 cm, an inner diameter of 2 cm, and an outer diameter of 4 cm. The gas distributor 9 has a G3 glass frit core. The gas chromatograph 12 is a GC-7820. The solution in the tail gas absorption bottle 11 is 20% industrial-grade sodium hypochlorite.

[0140] like Figure 7 The figure shows the curves of the desulfurization efficiency of the Schiff alkali metal complex liquid phase desulfurizers of Examples 1, 2 and 3 of the present invention as a function of desulfurization time. The horizontal axis Time / min is time, and the vertical axis Desulfurization efficiency / % is desulfurization efficiency. As can be seen from the figure, the desulfurization efficiency of the liquid phase desulfurizers prepared in Examples 1-3 of the present invention is 100%, which shows good desulfurization efficiency.

[0141] Example 4

[0142] The preparation method of the Schiff alkali metal complex liquid-phase desulfurizer described in this embodiment includes the following steps:

[0143] Step 1: Under stirring at 100 rpm, 50 mL of concentrated sulfuric acid was added dropwise at a rate of 80 drops / min to a three-necked flask containing 5.8 g of salicylaldehyde, and the mixture was heated to 35 °C and reacted for 18 h to obtain 50 mL of mixed solution A. 50 mL of mixed solution A was poured into 200 mL of ice water, and 50 g of anhydrous sodium carbonate was added. The mixture was stirred at 100 rpm for 150 min to neutralize the remaining concentrated sulfuric acid. Mixed solution A after neutralization was filtered under reduced pressure to obtain a light pink precipitate B. The light pink precipitate B was dissolved in 50 mL of hot water at 80 °C and recrystallized at 0 °C until the crystals were completely precipitated. The crystals were filtered to obtain crystal C. Crystal C was washed with acetone until it turned white. The washed crystal C was dried under vacuum at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain sulfosalicylic acid.

[0144] Step 2: Under a nitrogen atmosphere, 0.02 mol of sulfosalicylic aldehyde obtained in Step 1 and 100 mL of ethanol were added to a three-necked flask and heated under reflux at 68 °C for 0.5 h to disperse the solution evenly, resulting in mixed solution D. 0.01 mol of ethylenediamine was dissolved in 30 mL of ethanol to obtain mixed solution E. Mixed solution E was placed in a constant pressure dropping funnel and added dropwise at a rate of 80 drops / min to the three-necked flask containing mixed solution D. The mixture was reacted at 68 °C for 2 h to obtain mixed solution F. Mixed solution F was placed under 0 °C for 10 h and filtered to obtain yellow crystals G. Yellow crystals G were washed 3-5 times with 150 mL of 0 °C low-temperature ethanol solution. The washed crystals G were then vacuum dried at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain the Schiff base ligand.

[0145] Step 3: Under a nitrogen atmosphere, add 0.01 mol of the Schiff base ligand obtained in Step 2 and 80 mL of ethanol to a three-necked flask, heat and reflux at 68 °C for 3 h to disperse evenly, and obtain mixed solution H; dissolve 0.02 mol of cobalt acetate in 50 mL of ethanol to obtain mixed solution I; place mixed solution I in a constant pressure dropping funnel and add it dropwise at a rate of 80 drops / min to the three-necked flask containing mixed solution H, react at 100 °C for 3 h to obtain mixed solution J; place mixed solution J in a low temperature refrigeration condition at 0 °C, filter the refrigerated mixed solution J to obtain crystal K, wash crystal K with ethanol 3-5 times, filter the washed crystal K, and vacuum dry at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain the Schiff base metal complex;

[0146] Step 4: Add 0.5g of the Schiff alkali metal complex obtained in Step 3 to 1000mL of deionized water and stir to dissolve at room temperature to obtain the Schiff alkali metal complex liquid phase desulfurizer.

[0147] The application of the Schiff alkali metal complex liquid-phase desulfurizer described in this embodiment is for gas desulfurization, such as... Figure 12 The diagram shown is of a desulfurization device for gas desulfurization using Schiff alkali metal complex liquid-phase desulfurizer in this embodiment, including the following steps:

[0148] Step 1: Open the sulfur-containing raw material gas cylinder 1 containing 150 ppm dimethyl sulfide and the dilution gas cylinder 2. Control the flow rate of the sulfur-containing raw material gas flow meter 3 to 300 mL / min and the flow rate of the dilution gas flow meter 4 to 140 mL / min. Introduce the mixed gas cylinder 5 and mix evenly to obtain a mixed gas.

[0149] Step 2: Inject 30 mL of Schiff alkali metal complex liquid phase desulfurizer into the bubbling reactor 8, and heat the bubbling reactor 8 with a constant temperature water bath 10 to 30°C. Then, continuously introduce the mixed gas into the bubbling reactor 8 containing the Schiff alkali metal complex liquid phase desulfurizer through the gas distributor 9 at a flow rate of 30 mL / min using the mixed gas flow meter 6. The desulfurization time is 3 hours.

[0150] Step 3: Take the desulfurized Schiff alkali metal complex liquid-phase desulfurizer from the sampling port 7 of the bubbling reactor 8, and analyze the presence of anions, such as... Figure 8 The figure shows the presence of various anions in the solution after desulfurization by the Schiff alkali metal complex liquid-phase desulfurizing agent. The horizontal axis represents time (min), and the vertical axis represents the ionic conductivity (μs / cm). Figure 4 A comparison of the presence of various anions in the solution of the Schiff alkali metal complex liquid-phase desulfurizer before desulfurization revealed that SO42- in the desulfurized liquid-phase desulfurizer... 2- The significant increase indicates that the Schiff alkali metal complex liquid-phase desulfurizer converts dimethyl sulfide into SO4. 2- ;

[0151] Step 4: Take the desulfurized sulfur-containing raw material gas from the gas outlet at the top of the bubbling reactor 8, and use a gas chromatograph 12 to periodically detect the content of organic sulfur in the sulfur-containing raw material gas. The test results show that the concentration of dimethyl sulfide in the sulfur-containing raw material gas after dilution with dilution gas is 60 ppm, the content of dimethyl sulfide in the tail gas is 27 ppm, the desulfurization effect is 55%, and the desulfurized gas is passed into the tail gas absorption bottle 11 for recovery.

[0152] In this embodiment, the sulfur-containing raw material gas cylinder 1 contains 150 ppm dimethyl sulfide and nitrogen, with the nitrogen serving as the carrier gas. The dilution gas is oxygen. The bubbling reactor 8 has an effective height of 30 cm, an inner diameter of 2 cm, and an outer diameter of 4 cm. The gas distributor 9 has a G3 glass frit core. The gas chromatograph 12 is a GC-7820. The solution in the tail gas absorption bottle 11 is 20% industrial-grade sodium hypochlorite.

[0153] Example 5

[0154] The preparation method of the Schiff alkali metal complex liquid-phase desulfurizer described in this embodiment includes the following steps:

[0155] Step 1: Under stirring at 100 rpm, 50 mL of concentrated sulfuric acid was added dropwise at a rate of 80 drops / min to a three-necked flask containing 5.8 g of salicylaldehyde, and the mixture was heated to 35 °C and reacted for 18 h to obtain 50 mL of mixed solution A. 50 mL of mixed solution A was poured into 200 mL of ice water, and 50 g of anhydrous sodium carbonate was added. The mixture was stirred at 100 rpm for 150 min to neutralize the remaining concentrated sulfuric acid. Mixed solution A after neutralization was filtered under reduced pressure to obtain a light pink precipitate B. The light pink precipitate B was dissolved in 50 mL of hot water at 80 °C and recrystallized at 0 °C until the crystals were completely precipitated. The crystals were filtered to obtain crystal C. Crystal C was washed with acetone until it turned white. The washed crystal C was dried under vacuum at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain sulfosalicylic acid.

[0156] Step 2: Under a nitrogen atmosphere, 0.02 mol of sulfosalicylic aldehyde obtained in Step 1 and 100 mL of ethanol were added to a three-necked flask and heated under reflux at 68 °C for 0.5 h to disperse the solution evenly, resulting in mixed solution D. 0.01 mol of ethylenediamine was dissolved in 30 mL of ethanol to obtain mixed solution E. Mixed solution E was placed in a constant pressure dropping funnel and added dropwise at a rate of 80 drops / min to the three-necked flask containing mixed solution D. The mixture was reacted at 68 °C for 2 h to obtain mixed solution F. Mixed solution F was placed under 0 °C for 10 h and filtered to obtain yellow crystals G. Yellow crystals G were washed 3-5 times with 150 mL of 0 °C low-temperature ethanol solution. The washed crystals G were then vacuum dried at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain the Schiff base ligand.

[0157] Step 3: Under a nitrogen atmosphere, add 0.01 mol of the Schiff base ligand obtained in Step 2 and 80 mL of ethanol to a three-necked flask, heat and reflux at 68 °C for 3 h to disperse evenly, and obtain mixed solution H; dissolve 0.02 mol of ferric acetate in 50 mL of ethanol to obtain mixed solution I; place mixed solution I in a constant pressure dropping funnel and add it dropwise at a rate of 80 drops / min to the three-necked flask containing mixed solution H, react at 100 °C for 3 h to obtain mixed solution J; place mixed solution J in a low temperature refrigeration condition at 0 °C, filter the refrigerated mixed solution J to obtain crystal K, wash crystal K with ethanol 3-5 times, filter the washed crystal K, and vacuum dry at 110 °C for 48 h at a vacuum degree of -0.1 MPa to obtain the Schiff base metal complex;

[0158] Step 4: Add 0.5g of the Schiff alkali metal complex obtained in Step 3 to 1000mL of deionized water and stir to dissolve at room temperature to obtain the Schiff alkali metal complex liquid phase desulfurizer.

[0159] The application of the Schiff alkali metal complex liquid-phase desulfurizer described in this embodiment is for gas desulfurization, such as... Figure 12 The diagram shown is of a desulfurization device for gas desulfurization using Schiff alkali metal complex liquid-phase desulfurizer in this embodiment, including the following steps:

[0160] Step 1: Open the sulfur-containing raw material gas cylinder 1 containing 150 ppm dimethyl sulfide and the dilution gas cylinder 2. Control the flow rate of the sulfur-containing raw material gas flow meter 3 to 80 mL / min and the flow rate of the dilution gas flow meter 4 to 400 mL / min. Introduce the mixed gas cylinder 5 and mix evenly to obtain a mixed gas.

[0161] Step 2: Inject 30 mL of Schiff alkali metal complex liquid phase desulfurizer into the bubbling reactor 8, and heat the bubbling reactor 8 with a constant temperature water bath 10 to 30°C. Then, continuously introduce the mixed gas into the bubbling reactor 8 containing the Schiff alkali metal complex liquid phase desulfurizer through the gas distributor 9 at a flow rate of 30 mL / min using the mixed gas flow meter 6. The desulfurization time is 3 hours.

[0162] Step 3: Take the desulfurized sulfur-containing raw material gas from the gas outlet at the top of the bubbling reactor 8, and use a gas chromatograph 12 to periodically detect the content of organic sulfur in the sulfur-containing raw material gas. The test results show that the concentration of dimethyl sulfide in the sulfur-containing raw material gas after dilution with dilution gas is 100 ppm, the content of dimethyl sulfide in the tail gas is 60 ppm, the desulfurization effect is 40%, and the desulfurized gas is passed into the tail gas absorption bottle 11 for recovery.

[0163] In this embodiment, the sulfur-containing raw material gas cylinder 1 contains 150 ppm dimethyl sulfide and nitrogen, with the nitrogen serving as the carrier gas. The dilution gas is oxygen. The bubbling reactor 8 has an effective height of 30 cm, an inner diameter of 2 cm, and an outer diameter of 4 cm. The gas distributor 9 has a G3 glass frit core. The gas chromatograph 12 is a GC-7820. The solution in the tail gas absorption bottle 11 is 20% industrial-grade sodium hypochlorite.

[0164] like Figure 9 The figure shows the curves of the desulfurization efficiency of the Schiff alkali metal complex liquid phase desulfurizer in Examples 4 and 5 of the present invention as a function of desulfurization time. The horizontal axis Time / min represents time, and the vertical axis Desulfurizationefficiency / % represents desulfurization efficiency.

[0165] Comparative Example 1

[0166] The preparation method of this comparative desulfurizing agent includes the following steps:

[0167] Step 1: Based on the total mass of the desulfurizing agent, dissolve 2.9% sodium ferric ethylenediaminetetraacetate in 68.5% water by stirring thoroughly to obtain a sodium ferric ethylenediaminetetraacetate solution.

[0168] Step 2: Based on the total mass of the desulfurizing agent, add 13.9% potassium carbonate and 13.3% N-methyldiethanolamine to the sodium iron ethylenediaminetetraacetate solution, stir evenly, and obtain the desulfurizing agent.

[0169] The purpose of the desulfurizing agent described in this comparative example is to use it for gas desulfurization, such as... Figure 12 The diagram shown is of a desulfurization device for gas desulfurization using a desulfurizing agent in this comparative example, including the following steps:

[0170] Step 1: Open the sulfur-containing raw material gas cylinder 1 containing 200 ppm methanethiol and the dilution gas cylinder 2. Control the flow rate of the sulfur-containing raw material gas flow meter 3 to 200 mL / min and the flow rate of the dilution gas flow meter 4 to 100 mL / min. Introduce the mixed gas cylinder 5 and mix evenly to obtain a mixed gas.

[0171] Step 2: Inject 30 mL of desulfurizing agent into the bubbling reactor 8, and heat the bubbling reactor 8 with a constant temperature water bath 10. After heating to 30°C, the mixed gas is continuously introduced into the bubbling reactor 8 containing the desulfurizing agent through the gas distributor 9 at a flow rate of 30 mL / min using the mixed gas flow meter 6. The desulfurization time is 3 hours.

[0172] Step 3: Take the desulfurized sulfur-containing raw gas from the gas outlet at the top of the bubbling reactor 8, and use a gas chromatograph 12 to periodically detect the content of organic sulfur in the sulfur-containing raw gas. The test results show that the content of methanethiol in the tail gas is 89 ppm, and the desulfurization effect is 11%. The desulfurized gas is passed into the tail gas absorption bottle 11 for recovery.

[0173] In this embodiment, the sulfur-containing raw material gas cylinder 1 contains 200 ppm of methanethiol and nitrogen, with the nitrogen serving as the carrier gas. The dilution gas is oxygen. The bubbling reactor 8 has an effective height of 30 cm, an inner diameter of 2 cm, and an outer diameter of 4 cm. The gas distributor 9 has a G3 glass frit core. The gas chromatograph 12 is a GC-7820. The solution in the tail gas absorption bottle 11 is 20% industrial-grade sodium hypochlorite.

[0174] like Figure 10The figure shows the curve of the desulfurization efficiency of the desulfurizing agent in this comparative example as a function of desulfurization time. The horizontal axis is Time / min, and the vertical axis is Desulfurization efficiency / %. When the desulfurization time is 180h, the desulfurization efficiency is only 11%.

[0175] Comparative Example 2

[0176] The preparation method of this comparative desulfurizing agent includes the following steps:

[0177] Step 1: Based on the total mass of the desulfurizing agent, dissolve 2.9% sodium ferric ethylenediaminetetraacetate in 68.5% water by stirring thoroughly to obtain a sodium ferric ethylenediaminetetraacetate solution.

[0178] Step 2: Based on the total mass of the desulfurizing agent, add 13.9% potassium carbonate and 13.3% N-methyldiethanolamine to the sodium iron ethylenediaminetetraacetate solution obtained in Step 1, stir evenly, and obtain the desulfurizing agent.

[0179] The purpose of the desulfurizing agent described in this comparative example is to use it for gas desulfurization, such as... Figure 12 The diagram shown is of a desulfurization device for gas desulfurization using a desulfurizing agent in this comparative example, including the following steps:

[0180] Step 1: Open the sulfur-containing raw material gas cylinder 1 containing 150 ppm dimethyl sulfide and the dilution gas cylinder 2. Control the flow rate of the sulfur-containing raw material gas flow meter 3 to 100 mL / min and the flow rate of the dilution gas flow meter 4 to 300 mL / min. Introduce the mixed gas cylinder 5 and mix evenly to obtain a mixed gas.

[0181] Step 2: Inject 30 mL of desulfurizing agent into the bubbling reactor 8, and heat the bubbling reactor 8 with a constant temperature water bath 10. After heating to 30°C, the mixed gas is continuously introduced into the bubbling reactor 8 containing the desulfurizing agent through the gas distributor 9 at a flow rate of 30 mL / min using the mixed gas flow meter 6. The desulfurization time is 3 hours.

[0182] Step 3: Take the desulfurized sulfur-containing raw gas from the gas outlet at the top of the bubbling reactor 8, and use a gas chromatograph 12 to periodically detect the content of organic sulfur in the sulfur-containing raw gas. The test results show that the content of dimethyl sulfide in the tail gas is 36 ppm, and the desulfurization effect is 70%. The desulfurized gas is then passed into the tail gas absorption bottle 11 for recovery.

[0183] In this embodiment, the sulfur-containing raw material gas cylinder 1 contains 150 ppm dimethyl sulfide and nitrogen, with the nitrogen serving as the carrier gas. The dilution gas is oxygen. The bubbling reactor 8 has an effective height of 30 cm, an inner diameter of 2 cm, and an outer diameter of 4 cm. The gas distributor 9 has a G3 glass frit core. The gas chromatograph 12 is a GC-7820. The solution in the tail gas absorption bottle 11 is 20% industrial-grade sodium hypochlorite.

[0184] like Figure 11 The figure shows the curve of the desulfurization efficiency of the desulfurizing agent in this comparative example as a function of desulfurization time. The horizontal axis represents time (Time / min), and the vertical axis represents desulfurization efficiency (%). By comparing with... Figure 9 The comparison shows that the demethyl sulfide removal efficiency of the Schiff alkali metal complex liquid-phase desulfurizer prepared in this invention is higher than that of the comparative example within a desulfurization time of 0-60h.

[0185] Based on the above performance, it can be seen that the Schiff alkali metal complex liquid phase desulfurizer described in this patent has a high desulfurization rate and is not only applicable to methanethiol and dimethyl sulfide, but also to the desulfurization of organic sulfur such as thiols and sulfides. It has a low preparation cost and has a very high market prospect.

[0186] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

[0187] It should be understood that the present invention is not limited to what has been described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. The use of a Schiff alkali metal complex liquid-phase desulfurizing agent, characterized in that, The Schiff alkali metal complex liquid-phase desulfurizer is used for gas desulfurization, and the desulfurization process includes the following steps: Step 1: Mix the sulfur-containing raw material gas and the dilution gas to obtain a mixed gas; Step 2: Inject the Schiff alkali metal complex liquid phase desulfurizer into the reactor, heat it to the reaction temperature, and then introduce the mixed gas into the reactor for desulfurization. The sulfur-containing raw material gas in step 1 contains nitrogen and organic sulfur gas, wherein the organic sulfur gas is one of methanethiol or dimethyl sulfide, and the dilution gas is one of oxygen or air, and the nitrogen is the carrier gas. The reactor in step 2 is a bubbling reactor. The mixed gas first passes through a gas distributor and then is introduced into the bubbling reactor containing Schiff alkali metal complex liquid phase desulfurizer in a bubbling manner. The gas distributor is a G3 glass frit core. The structure of the Schiff alkali metal complex liquid-phase desulfurizer is as follows: Where R1 is -CH2CH2-, M is Co, M n+ In this case, n is greater than or equal to 1.

2. The use of the Schiff alkali metal complex liquid-phase desulfurizer according to claim 1, characterized in that, The desulfurization temperature in step 2 is 30℃, and the reaction time is 3h.

3. The use of the Schiff alkali metal complex liquid-phase desulfurizer according to claim 1, characterized in that, The preparation method of the Schiff alkali metal complex liquid-phase desulfurizer includes the following steps: Step 1: Under stirring conditions, concentrated sulfuric acid is added dropwise to salicylaldehyde, and the mixture is heated to the reaction temperature to carry out the reaction. After the reaction, a mixed solution A is obtained. Mixed solution A is poured into ice water, and anhydrous sodium carbonate is added. The mixture is stirred to neutralize the remaining concentrated sulfuric acid. The mixed solution A after neutralization of concentrated sulfuric acid is filtered under reduced pressure to obtain a light pink precipitate B. The light pink precipitate B is dissolved in hot water and recrystallized until the crystals are completely precipitated. The crystals are filtered to obtain crystal C. Crystal C is washed with acetone until it turns white, and the washed crystal C is dried under vacuum to obtain sulfosalicylic aldehyde. Step 2: Under a nitrogen atmosphere, the sulfosalicylic aldehyde is added to ethanol, heated to reflux, and dispersed evenly to obtain a mixed solution D; ethylenediamine is dissolved in ethanol to obtain a mixed solution E; mixed solution E is placed in a constant pressure dropping funnel and added dropwise to mixed solution D to react, obtaining a mixed solution F; mixed solution F is refrigerated at low temperature, and the refrigerated mixed solution F is filtered to obtain yellow crystals G; yellow crystals G are washed 3-5 times with low temperature ethanol solution, and vacuum dried to obtain Schiff base ligands; Step 3: Under a nitrogen atmosphere, the Schiff base ligand is added to ethanol, heated to reflux, and dispersed evenly to obtain a mixed solution H; the transition metal salt is dissolved in ethanol to obtain a mixed solution I; mixed solution I is placed in a constant pressure dropping funnel and added dropwise to mixed solution H to react, obtaining a mixed solution J; mixed solution J is refrigerated at low temperature, and the refrigerated mixed solution J is filtered to obtain crystal K; crystal K is washed with ethanol 3-5 times, filtered, and vacuum dried to obtain the Schiff base metal complex; Step 4: Add the Schiff base metal complex to a solvent and stir to dissolve it at room temperature to obtain a Schiff base metal complex liquid-phase desulfurizer.

4. The use of the Schiff alkali metal complex liquid-phase desulfurizer according to claim 3, characterized in that, In step 1, the mass ratio of salicylaldehyde to concentrated sulfuric acid is (10:1)-(18:1); the reaction temperature is 30-50℃.

5. The use of the Schiff alkali metal complex liquid-phase desulfurizer according to claim 3, characterized in that, In step 2, the volume ratio of the mixed solution D to the mixed solution E is (10:1) - (10:5).

6. The use of the Schiff alkali metal complex liquid-phase desulfurizer according to claim 3, characterized in that, The transition metal salt mentioned in step 3 is cobalt acetate.

7. The use of the Schiff alkali metal complex liquid-phase desulfurizer according to claim 3, characterized in that, The concentration of the Schiff alkali metal complex in the liquid-phase desulfurizing agent of the Schiff alkali metal complex in step 4 is 100-10000 mg / L.

Images