Preparation method of high-purity triethylamine

Abstract

This invention provides a method for preparing high-purity triethylamine, belonging to the field of chemical synthesis technology. In the presence of a catalyst and hydrogen, ammonia and ethanol undergo a catalytic reaction to obtain an ethylamine mixture; the ethylamine mixture is then distilled to obtain distilled triethylamine; the distilled triethylamine is then adsorbed using an adsorbent to obtain high-purity triethylamine, wherein the total impurity content of the high-purity triethylamine is ≤0.3%, and the total metal impurity content is ≤1.5ppm; the catalyst is a porous composite transition metal oxide; the adsorbent is an acylhydrazone-based organic framework material, which is obtained by polymerization of raw materials including aldehyde monomers and acylhydrazine monomers. This invention utilizes an acylhydrazone-based organic framework material to effectively adsorb impurity ions in triethylamine, ultimately obtaining high-purity triethylamine.

Description

Technical Field

[0001] This invention relates to the field of chemical synthesis technology, and in particular to a method for preparing high-purity triethylamine. Background Technology

[0002] Triethylamine (molecular formula C6H) 15 Triethylamine (TEA), as a fundamental organic chemical raw material, occupies an important position in the global chemical industry and is widely used in the manufacture of high-energy-density fuels and high-end electronic chemicals. The industrial production method of triethylamine mainly employs the catalytic synthesis method using ethanol and ammonia. Specifically, under high temperature and pressure conditions in the presence of a catalyst, a mixed ethylamine (containing monoethylamine, diethylamine, and triethylamine) is produced, which is then separated to obtain the target product, triethylamine. In related preparation processes, if metal-containing catalysts are used, this is usually the main source of metal ions in the triethylamine product. In addition, corrosion of distillation equipment at high temperatures, as well as subsequent transfer and storage processes, may also introduce additional metal ion contamination. Furthermore, certain fields, such as aerospace, have high purity requirements for triethylamine, typically requiring an impurity content of ≤0.3%, especially regarding the metal ion content. As a high-energy-density fuel, metal ions have redox properties and may trigger redox reactions, leading to propellant failure or safety accidents. As a high-end electronic chemical, certain ions can cause ion contamination in semiconductor processes or performance degradation in lithium batteries. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing high-purity triethylamine. This invention uses acylhydrazone-based organic framework materials that can effectively adsorb impurity ions such as metal ions in triethylamine, and finally obtain high-purity triethylamine.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing high-purity triethylamine, comprising the following steps: Ammonia and ethanol are catalytically reacted in the presence of a catalyst and hydrogen to produce a mixture of ethylamine. The ethylamine mixture was subjected to distillation to obtain distilled triethylamine; The distilled triethylamine was subjected to adsorption treatment with an adsorbent to obtain high-purity triethylamine, wherein the total impurity content of the high-purity triethylamine is ≤0.3% and the total metal impurity content is ≤1.5ppm; The catalyst is a porous composite transition metal oxide; The adsorbent is an acylhydrazone organic framework material, which is obtained by polymerization of raw materials including aldehyde monomers and acylhydrazine monomers. The aldehyde monomer has the structure shown in Formula II-1, Formula II-2 or Formula II-3: Formula II-1; Formula II-2; Formula II-3; The hydrazide monomer has the structure shown in Formula III-1, Formula III-2 or Formula III-3: Formula III-1; Formula III-2; Formula III-3; The R is selected from methylene, nitrogen atom, phenyl or triazine group; R1 is selected from propyl, allyl, benzyl, or... N,N -Dimethylethylamino; R2 is selected from methine, nitrogen atom, phenyl or triazine group.

[0005] Preferably, the porous composite transition metal oxide comprises an XY2O4 type porous matrix material and an active component supported on the surface of the XY2O4 type porous matrix material; wherein X is selected from Co or Cu, Y is selected from Mn or Fe, and the active component is selected from one or more of PtO2, IrO2 and RuO2.

[0006] Preferably, the content of the active component in the porous composite transition metal oxide is 0.5~10wt%.

[0007] Preferably, the porous composite transition metal oxide has a pore size of 5-100 nm, a particle size of 200-500 nm, and a specific surface area of ​​50-200 m². 2 / g.

[0008] Preferably, the molar ratio of ethanol to ammonia is 0.5 to 3:1.

[0009] Preferably, the conditions for the catalytic reaction include: a temperature of 120~160℃, a pressure of 0.6~1.8MPa, and a total volume hourly space velocity (VHSV) of 0.1~0.4h for ammonia and ethanol. -1 .

[0010] Preferably, the conditions for the adsorption treatment include: a temperature of 25~60℃ and a volume hourly space velocity (VHSV) of 0.1~0.4 h⁻¹ for the distillation of triethylamine. -1 .

[0011] Preferably, the impurities in the high-purity triethylamine include metallic impurities and non-metallic impurities, wherein the non-metallic impurities include Cl. - Et4N + One or more of water, ethanol and diethylamine.

[0012] Preferably, the metallic impurity includes Mn. 2+ Cu2+ Cd 2+ Ni 2+ Fe 3+ Fe 2+ Co 2+ Pt 4+ Ir 4+ and Ru 4+ One or more of them.

[0013] Beneficial effects: This invention utilizes acylhydrazone-based organic framework materials to effectively adsorb metallic impurities (such as metal ions Mn) from triethylamine. 2+ Cu 2+ Cd 2+ Ni 2+ Fe 3+ Fe 2+ Co 2+ Pt 4+ Ir 4+ Ru 4+ And non-metallic impurities (such as non-metallic ions Cl-). - Et4N + Et4N + Abbreviated as N 4444 + The process ultimately yields high-purity triethylamine. Specifically, the acylhydrazone-based organic framework material in this invention possesses a high density of nitrogen-containing functional groups such as acylhydrazone groups. It can form stable coordination structures with metal ions in the triethylamine system and synergistically enhance the adsorption effect through multiple interactions such as electrostatic interactions and hydrogen bonding, thereby achieving a high metal ion adsorption capacity and removal rate, demonstrating excellent adsorption performance and application potential. Meanwhile, in the preparation of triethylamine using the ethanol-catalyzed amination method, triethylamine and ethanol undergo excessive alkylation, thereby generating N... 4444 + In this invention, acylhydrazone-based organic framework materials can achieve N through multiple interactions such as electrostatic interactions, π-cation interactions, and hydrogen bonding. 4444 + Therefore, this invention uses the acylhydrazone-based organic framework material as an adsorbent in the ethanol-catalyzed amination method to prepare triethylamine, which can effectively adsorb impurity ions in triethylamine, ultimately obtaining high-purity triethylamine, which can be applied to missile propellants or high-end electronic chemicals.

[0014] Furthermore, in the preparation of triethylamine using the ethanol-catalyzed amination method, this invention employs a porous composite transition metal oxide (M@XY2O4) as a catalyst. Its porous structure significantly increases its specific surface area. As a catalyst in the ethanol-catalyzed amination method for triethylamine preparation, a larger specific surface area means more active sites available for the reactants to contact the catalyst, allowing for more complete interaction between the reactants and the catalyst, thus accelerating the reaction process. Simultaneously, the porous structure helps increase the residence time of the reactants on the catalyst surface, thereby improving the conversion rate of the reactants (ammonia).

[0015] Furthermore, the specific type of XY₂O₄ porous matrix material in the porous composite transition metal oxide of the present invention, combined with specific types of active components, can further promote the disproportionation reaction of monoethylamine and diethylamine to generate triethylamine, which is beneficial to further improve the yield of triethylamine. Application examples show that when using the porous composite transition metal oxide provided by the present invention as a catalyst in the ethanol-catalyzed amination method for preparing triethylamine, the yield of triethylamine is consistently above 50%, achieving highly efficient preparation of triethylamine. Attached Figure Description

[0016] Figure 1 The N2 adsorption / desorption isotherm of the Tf-DHzOPr acylhydrazone organic framework material in Example 5 is shown. Figure 2 The pore size distribution of the Tf-DHzOPr acylhydrazone organic framework material in Example 5 is shown in Figure 5. Figure 3 The XRD pattern of the Tf-DHzOPr acylhydrazone organic framework material in Example 5; Figure 4 The N2 adsorption / desorption isotherm of the TFPB-DHzOPr acylhydrazone organic framework material in Example 6 is shown. Figure 5 Pore ​​size distribution diagram of the TFPB-DHzOPr acylhydrazone organic framework material in Example 6; Figure 6 The XRD pattern of the TFPB-DHzOPr acylhydrazone organic framework material in Example 6; Figure 7 To prepare the acylhydrazone-based organic framework materials obtained in Examples 5-8, the reaction of Mn in triethylamine solution was carried out. 2+ Adsorption capacity and removal rate graph; Figure 8 To prepare the acylhydrazone-based organic framework materials obtained in Examples 5-8, the adsorption of Mn from triethylamine solution before and after the adsorption was investigated. 2+ Concentration comparison chart; Figure 9 To prepare the acylhydrazone-based organic framework materials obtained in Examples 5-8, the N in triethylamine solution... 4444+ Adsorption capacity and removal rate graph. Detailed Implementation

[0017] This invention provides a method for preparing high-purity triethylamine, comprising the following steps: Ammonia and ethanol are catalytically reacted in the presence of a catalyst and hydrogen to produce a mixture of ethylamine. The ethylamine mixture was subjected to distillation to obtain distilled triethylamine; The distilled triethylamine was subjected to adsorption treatment with an adsorbent to obtain high-purity triethylamine, wherein the total impurity content of the high-purity triethylamine is ≤0.3% and the total metal impurity content is ≤1.5ppm; The catalyst is a porous composite transition metal oxide; The adsorbent is an acylhydrazone organic framework material, which is obtained by polymerization of raw materials including aldehyde monomers and acylhydrazine monomers. The aldehyde monomer has the structure shown in Formula II-1, Formula II-2 or Formula II-3: Formula II-1; Formula II-2; Formula II-3; The hydrazide monomer has the structure shown in Formula III-1, Formula III-2 or Formula III-3: Formula III-1; Formula III-2; Formula III-3; The R is selected from methylene, nitrogen atom, phenyl or triazine group; R1 is selected from propyl, allyl, benzyl, or... N,N -Dimethylethylamino; R2 is selected from methine, nitrogen atom, phenyl or triazine group.

[0018] In this invention, unless otherwise specified, all raw materials used are commercially available products well known to those skilled in the art or prepared using methods well known to those skilled in the art.

[0019] This invention prepares triethylamine under the catalysis of a catalyst. The catalyst will be described in detail below.

[0020] The catalyst described in this invention is a porous composite transition metal oxide. In one embodiment of this invention, the pore size of the porous composite transition metal oxide can be 5-100 nm, more specifically 5-50 nm; the particle size can be 200-500 nm, more specifically 200-300 nm, 300-400 nm, or 400-500 nm; and the specific surface area can be 50-200 m² / g.2 / g, which can be further increased to 50m 2 / g、88m 2 / g、171m 2 / g or 200m 2 / g. This invention uses porous composite transition metal oxides with the above-mentioned pore size, particle size, and specific surface area as catalysts to prepare triethylamine. This increases the contact area between the catalyst and the raw materials, allowing for sufficient contact between the catalyst and the raw materials, improving the catalytic reaction effect, and thus achieving efficient preparation of triethylamine.

[0021] In one embodiment of the present invention, the porous composite transition metal oxide may include an XY2O4 type porous matrix material and an active component supported on the surface of the XY2O4 type porous matrix material, that is, the porous composite transition metal oxide is a supported catalyst (denoted as M@XY2O4); the content of the active component in the porous composite transition metal oxide can be 0.5~10wt%, specifically 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt%, or 10wt%. By controlling the content of the active component within the above range, the present invention enables a more uniform loading of the active component, increases the number of active sites, and further improves the catalytic performance of the catalyst.

[0022] In one embodiment of the present invention, X is selected from Co or Cu, Y is selected from Mn or Fe, and the active component (M) is selected from one or more of PtO2, IrO2, and RuO2. Specifically, M@XY2O4 in the embodiments of the present invention can be PtO2@CoMn2O4, PtO2@CoFe2O4, IrO2@CuMn2O4, IrO2@CuFe2O4, RuO2@CoFe2O4, or RuO2@CuFe2O4. The present invention uses the above-mentioned types of M@XY2O4 to catalyze the reaction of ethanol and ammonia. First, ethanol and ammonia undergo an amination reaction under the catalysis of M@XY2O4 to generate monoethylamine, diethylamine, and triethylamine. Monoethylamine and diethylamine undergo a disproportionation reaction under the catalysis of M@XY2O4 to generate triethylamine and ammonia, thus resulting in a high yield of triethylamine, which is beneficial for the efficient synthesis of triethylamine. The relevant reaction formulas are shown below: ; .

[0023] As one embodiment of the present invention, the method for preparing the porous composite transition metal oxide may include the following steps: An adsorbed metal salt template is obtained by mixing an X-containing metal salt, a Y-containing metal salt, an ordered mesoporous SiO2 template, water, and an organic solvent. The adsorbed metal salt template was calcined to obtain the precursor. The precursor was mixed with an alkaline solution and subjected to template removal treatment to obtain an XY2O4 type porous matrix material. The XY2O4 type porous matrix material, the metal salt corresponding to M, and water are mixed and subjected to loading treatment to obtain a loaded metal salt matrix material. The loaded metal salt matrix material is calcined to obtain the porous composite transition metal oxide.

[0024] This invention involves mixing a metal salt containing X, a metal salt containing Y, an ordered mesoporous SiO2 template, water, and an organic solvent, followed by adsorption treatment to obtain an adsorbed metal salt template. In one embodiment of this invention, the ordered mesoporous SiO2 template has a honeycomb-like regular pore structure; the specific surface area of ​​the ordered mesoporous SiO2 template can be 600~700 m². 2 / g, specifically 685m 2 / g; the average pore size of the ordered mesoporous SiO2 template can be 7~8nm, specifically 7.7nm. In an embodiment of the present invention, the preparation method of the ordered mesoporous SiO2 template is as follows: 18g of Pluronic® P-123 and 30mL of 12mol / L hydrochloric acid are added to 651mL of water and stirred at 35°C until completely dissolved. 18g of n-butanol is added and stirred at 35°C for 1h. Then, 38.7g of tetraethyl orthosilicate is added and stirred at 35°C for 24h. The mixture is then heated at 100°C for 24h under sealed conditions. After cooling to room temperature, the mixture is filtered. The filter cake is washed with ethanol and heated from room temperature to 550°C at a heating rate of 1.5°C / min in air. The mixture is then calcined for 5h under heat treatment to obtain the ordered mesoporous SiO2 template.

[0025] After obtaining the ordered mesoporous SiO2 template, this invention mixes an X-containing metal salt, a Y-containing metal salt, the ordered mesoporous SiO2 template, water, and an organic solvent. In one embodiment of this invention, the X-containing metal salt and the Y-containing metal salt can be independently nitrates or hydrochlorides; the molar ratio of X to Y in the X-containing metal salt and the Y-containing metal salt can be 1:1.8~2.2, specifically 1:2. By limiting the molar ratio of X to Y in the X-containing metal salt and the Y-containing metal salt to the above range, this invention can obtain an XY2O4 type porous matrix material. In one embodiment of this invention, the ratio of the total mass of the X-containing metal salt and the Y-containing metal salt to the volume of water can be 50~80g:100mL, specifically 53g:100mL, 54g:100mL, 60g:100mL, 65g:100mL, 70g:100mL, or 74g:100mL. In one embodiment of the present invention, the mass ratio of the ordered mesoporous SiO2 template to the total mass of the metal salt containing X and the metal salt containing Y can be 10~30:4~8, specifically 10:5.3, 10:5.4, 10:6, 10:6.5, 10:7, or 10:7.4. By limiting the mass ratio of the ordered mesoporous SiO2 template to the total mass of the metal salt containing X and the metal salt containing Y within the above range, the present invention enables the catalyst to have suitable pore size and specific surface area, which is beneficial to improving the catalytic performance of the catalyst. In another embodiment of the present invention, the organic solvent may include n-hexane, cyclohexane, or petroleum ether; the mass ratio of the ordered mesoporous SiO2 template to the volume ratio of the organic solvent can be 10g:150~450mL, specifically 10g:250mL, 10g:300mL, or 10g:350mL.

[0026] In one embodiment of the present invention, the X-containing metal salt, the Y-containing metal salt, the ordered mesoporous SiO2 template, water, and organic solvent are mixed. Specifically, the X-containing metal salt and the Y-containing metal salt are mixed with water to obtain an aqueous solution of the metal salt; the ordered mesoporous SiO2 template is mixed with an organic solvent to obtain a template dispersion; and the aqueous solution of the metal salt is mixed with the template dispersion.

[0027] In one embodiment of the present invention, the adsorption treatment can be carried out under stirring conditions, and the adsorption treatment time can be 2-4 hours, specifically 2.5 hours, 3 hours, or 3.5 hours; the adsorption treatment can be carried out at room temperature. Under the above conditions, the present invention can fully adsorb metal salts containing X and metal salts containing Y onto the ordered mesoporous SiO2 template. In another embodiment of the present invention, after the adsorption treatment, the resulting liquid is preferably subjected to solid-liquid separation, and the resulting solid material is the adsorbed metal salt template; the solid-liquid separation method can be vacuum filtration.

[0028] After obtaining the adsorbed metal salt template, the present invention calcines the adsorbed metal salt template to obtain a precursor. In one embodiment of the present invention, the calcination temperature can be 450~850℃, specifically 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, or 850℃; the holding time can be 2~6h, specifically 2h, 3h, 4h, 5h, or 6h; the calcination can be carried out in an air atmosphere. In the present invention, during the calcination process, the metal salt containing X reacts with the metal salt containing Y to generate an XY2O4 type porous matrix material. By limiting the calcination temperature and time within the above range, the present invention enables the metal salt containing X and the metal salt containing Y to fully react and form the XY2O4 type porous matrix material.

[0029] After obtaining the precursor, the present invention mixes the precursor with an alkaline solution and performs a template removal treatment to obtain an XY2O4 type porous matrix material. In one embodiment of the present invention, the alkaline solution may include one or more of sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, and lithium hydroxide aqueous solution; the concentration of the alkaline solution may be 0.5~3 mol / L, specifically 0.5 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, or 3 mol / L; the mass ratio of the ordered mesoporous SiO2 template to the volume of the alkaline solution may be 10 g: 500~700 mL, specifically 10 g: 550 mL, 10 g: 600 mL, or 10 g: 650 mL. In one embodiment of the present invention, the template removal treatment can be performed at room temperature; the present invention does not have a special limitation on the time of the template removal treatment, as long as the ordered mesoporous SiO2 template is sufficiently removed. In one embodiment of the present invention, after the template removal process, the resulting liquid is preferably subjected to solid-liquid separation, and the resulting solid material is the XY2O4 type porous matrix material; the solid-liquid separation method can be vacuum filtration.

[0030] After obtaining the XY2O4 porous matrix material, this invention mixes the XY2O4 porous matrix material, the metal salt corresponding to M, and water, and performs a loading treatment to obtain a loaded metal salt matrix material. In one embodiment of this invention, the metal salt corresponding to M specifically refers to a salt containing the metal in M, and the metal salt corresponding to M can be a nitrate or a hydrochloride; the mass ratio of the XY2O4 porous matrix material to the metal salt corresponding to M can be 10~30:0.1~2.5, specifically 10:0.5, 10:1, 10:1.5, 10:1.7, or 10:2. By limiting the mass ratio of the XY2O4 porous matrix material to the metal salt corresponding to M within the above range, this invention can control the loading of the active component in the catalyst, further improving the catalytic performance of the catalyst. As one embodiment of the present invention, the mass ratio of the metal salt corresponding to M to the volume ratio of water can be 1~25g:100mL, specifically 5g:100mL, 10g:100mL, 15g:100mL, 17g:100mL or 20g:100mL.

[0031] In one embodiment of the present invention, the XY2O4 porous matrix material, the M-corresponding metal salt, and water are mixed. Specifically, the M-corresponding metal salt is mixed with water to obtain a metal salt solution, and then the metal salt solution is mixed with the XY2O4 porous matrix material. In another embodiment, the loading treatment can be carried out under stirring conditions, and the loading treatment time can be 2-4 hours, specifically 2.5 hours, 3 hours, or 3.5 hours; the loading treatment can be carried out at room temperature. Under the above conditions, the present invention can fully load the M-corresponding metal salt onto the XY2O4 porous matrix material. In another embodiment, after the loading treatment, the resulting liquid is preferably subjected to solid-liquid separation, and the resulting solid material is the adsorbed metal salt template; the solid-liquid separation method can be vacuum filtration.

[0032] After obtaining the loaded metal salt matrix material, the present invention calcines the loaded metal salt matrix material to obtain the porous composite transition metal oxide. In one embodiment of the present invention, the calcination temperature is 500~850℃, specifically 550℃, 600℃, 650℃, 700℃, 750℃, or 800℃; the holding time is 2~4h, specifically 2h, 2.5h, 3h, 3.5h, or 4h; the calcination can be carried out in an air atmosphere. In the present invention, during the calcination process, the metal salt corresponding to M reacts to generate metal oxides (i.e., the active component) which are loaded onto the surface of the XY2O4 type porous matrix material. By controlling the calcination temperature and time within the above range, the present invention enables the metal salt corresponding to M to fully react and generate metal oxides.

[0033] After obtaining the porous composite transition metal oxide, this invention uses the porous composite transition metal oxide as a catalyst to catalyze the reaction of ammonia and ethanol in the presence of the catalyst and hydrogen, yielding an ethylamine mixture. In one embodiment of this invention, liquid ammonia and ethanol are preferably mixed and vaporized to obtain a vaporized gas; the vaporized gas and hydrogen are then introduced into a reactor containing the catalyst for a catalytic reaction. In another embodiment of this invention, the molar ratio of ethanol to ammonia in the vaporized gas can be 0.5 to 3:1, specifically 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, or 3:1. This invention does not have specific limitations on the vaporization method or conditions, as long as sufficient vaporization of liquid ammonia and ethanol is ensured. Limiting the molar ratio of ethanol to ammonia within the above range maintains a suitable ammonia partial pressure in the reaction zone, which is beneficial for promoting the cascade reaction of continuous amination of ethanol to ethylamine, diethylamine, and finally triethylamine, while suppressing side reactions such as intermolecular dehydration of ethanol to form diethyl ether or olefins.

[0034] In one embodiment of the present invention, the conditions for the catalytic reaction include: a temperature of 120~160℃, specifically 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, or 160℃; a pressure of 0.6~1.8MPa, specifically 0.6MPa, 0.8MPa, 1MPa, 1.3MPa, 1.5MPa, or 1.8MPa, wherein the pressure is provided by both vaporized gas and hydrogen; and a total volume hourly space velocity (VHSV) of 0.1~0.4h⁻¹ for ammonia and ethanol. -1 Specifically, it can be 0.1h -1 0.2h -1 0.3h -1 or 0.4h -1 The volume hourly space velocity (VHSV) of hydrogen is 0.01–0.2 h⁻¹. -1 Specifically, it can be 0.01h. -1 0.14h -1 0.17h -1 or 0.2h -1 The reaction time can be 2 to 4 hours, specifically 2 hours, 2.5 hours, 3 hours, 3.5 hours, or 4 hours. Under the above conditions, the present invention provides an optimal thermodynamic and kinetic environment for the amination step, which is beneficial for the uniform distribution of reactants and efficient mass transfer in the catalyst bed.

[0035] In one embodiment of the present invention, the reactor used for the catalytic reaction can be a fluidized bed reactor, specifically a tubular fixed bed reactor. In this embodiment, ethanol and liquid ammonia are first mixed as a reaction liquid, which is then introduced into the tubular fixed bed reactor. After vaporization in the vaporization chamber at the top of the reactor, vaporized gas is obtained. This vaporized gas, along with hydrogen, is then introduced into the catalyst bed inside the reactor, controlling the volume hourly space velocity (VHSV) of the reaction liquid to be 0.1–0.4 h⁻¹. -1 The volume hourly space velocity (VHSV) of hydrogen is 0.01–0.2 h⁻¹. -1 The pressure inside the reactor is controlled at 0.6~1.8 MPa, and the temperature inside the reactor is set at 120~160℃ to carry out the catalytic reaction. In one embodiment of the invention, the resulting product system is preferably condensed after the catalytic reaction to obtain an ethylamine mixture.

[0036] After obtaining the ethylamine mixture, the present invention further distills the ethylamine mixture to obtain distilled triethylamine. The present invention achieves preliminary separation of triethylamine from impurities through distillation. The present invention does not impose any special limitations on the specific conditions of the distillation; conditions well known to those skilled in the art can be used.

[0037] After obtaining distilled triethylamine, the present invention uses an adsorbent to adsorb the distilled triethylamine to obtain high-purity triethylamine, wherein the total impurity content of the high-purity triethylamine is ≤0.3% and the total metal impurity content is ≤1.5ppm; the adsorbent is an acylhydrazone organic framework material, which is obtained by polymerization reaction of raw materials including aldehyde monomers and acylhydrazine monomers; The aldehyde monomer has the structure shown in Formula II-1, Formula II-2 or Formula II-3: Formula II-1; Formula II-2; Formula II-3; The hydrazide monomer has the structure shown in Formula III-1, Formula III-2 or Formula III-3: Formula III-1; Formula III-2; Formula III-3; The R is selected from methylene, nitrogen atom, phenyl or triazine group; R1 is selected from propyl, allyl, benzyl, or... N,N -Dimethylethylamino; R2 is selected from methine, nitrogen atom, phenyl or triazine group.

[0038] In one embodiment of the present invention, the aldehyde monomer is triphenylmethane and the acylhydrazine monomer is 2,5-dipropoxy-terephthalohydrazine; or the aldehyde monomer is 1,3,5-tris(p-formylphenyl)benzene and the acylhydrazine monomer is 2,5-dipropoxy-terephthalohydrazine; or the aldehyde monomer is triphenylmethane and the acylhydrazine monomer is 2,5-bis(allyloxy)-terephthalohydrazine; or the aldehyde monomer is triphenylmethane and the acylhydrazine monomer is 2,5-bis(benzyloxy)-terephthalohydrazine.

[0039] In this embodiment of the invention, taking triphenylformaldehyde as the aldehyde monomer and 2,5-dipropoxyterephthalic acid hydrazide as the acylhydrazone monomer as an example, the structural formula of the acylhydrazone-based organic framework material is as follows: .

[0040] In one embodiment of the present invention, the acylhydrazone-based organic framework material has a large specific surface area, which can be 200~2000 m². 2 / g, specifically 216m 2 / g、272m 2 / g、1158m 2 / g or 1849m 2 / g. In one embodiment of the present invention, the acylhydrazone-based organic framework material has a high total pore volume, ranging from 0.15 to 1.25 cm³. 3 / g, specifically 0.17cm 3 / g, 0.22cm 3 / g, 0.58cm 3 / g or 1.23cm 3 / g. As one embodiment of the present invention, the acylhydrazone-based organic framework material has an antiparallel structure and good crystallinity.

[0041] As one embodiment of the present invention, the preparation method of the acylhydrazone organic framework material includes the following steps: mixing aldehyde monomers, acylhydrazine monomers and melt additives, and carrying out melt polymerization reaction to obtain the acylhydrazone organic framework material.

[0042] In one embodiment of the present invention, the molar ratio of the aldehyde monomer to the hydrazone monomer can be 1:1 to 1.5, specifically 1:1 or 1:1.5. In another embodiment, the melt flux can include benzoic anhydride, benzoic acid, 4-aminoacetophenone, methyl 4-aminobenzoate, maleic acid, or benzimidazole, specifically benzoic acid or 4-aminoacetophenone; the molar ratio of the melt flux to the aldehyde monomer can be 2 to 6:1, specifically 2:1, 3:1, 4:1, 5:1, or 6:1. The use of melt fluxes of the above types and amounts in the present invention is beneficial for the formation of a well-developed and ordered porous structure in hydrazone-based organic framework materials.

[0043] In one embodiment of the present invention, the aldehyde monomer, hydrazide monomer, and melt additive are mixed and preferably ground before the melt polymerization reaction is carried out. Grinding facilitates uniform mixing of the components in this invention. In another embodiment, the temperature of the melt polymerization reaction can be 120~200℃, specifically 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, or 200℃; the time can be 2~5 days, specifically 2 days, 3 days, 4 days, or 5 days. By limiting the temperature and time of the melt polymerization reaction to the above ranges, this invention facilitates the formation of a well-developed and ordered porous structure in the hydrazone-based organic framework material.

[0044] In one embodiment of the present invention, the melt polymerization reaction preferably further includes: cooling the product system obtained from the melt polymerization reaction and then sequentially washing and activating it to obtain the acylhydrazone-based organic framework material. In one embodiment of the present invention, the cooling specifically involves cooling the product system to room temperature; the washing reagents can be N,N-dimethylformamide, acetone, and methanol sequentially, and the washing method can be immersion washing, with the immersion washing time for each reagent independently ranging from 1 to 6 hours, specifically 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, or 6 hours; the present invention can remove unreacted monomers and generated impurities through washing. In one embodiment of the present invention, the activation can include sequential Soxhlet extraction and vacuum drying; the reagent used for Soxhlet extraction can include tetrahydrofuran; the Soxhlet extraction time can be 45 to 50 hours, specifically 48 hours; the vacuum drying temperature can be 70 to 90°C, specifically 80°C; and the vacuum drying time can be 20 to 30 hours, specifically 24 hours. This invention enables the activation of acylhydrazone-based organic framework materials by removing unreacted monomers and generated impurities through Soxhlet extraction and removing solvents through vacuum drying.

[0045] The acylhydrazone-based organic framework materials of this invention are effective against metal ions such as Mn. 2+ Cu 2+ Cd2+ Ni 2+ Fe 3+ Fe 2+ Co 2+ Pt 4+ Ir 4+ Ru 4+ It exhibits excellent adsorption effects, and is also effective against other cations such as N. 4444 + and anions such as Cl - It also has excellent adsorption effect and can be used to remove impurities from triethylamine to ensure high-purity triethylamine.

[0046] In one embodiment of the present invention, the conditions for the adsorption treatment include: a temperature of 25~60℃, specifically 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, or 60℃; and a volume hourly space velocity (VHSV) of 0.1~0.4 h⁻¹ for the distillation of triethylamine. -1 Specifically, it can be 0.1h -1 0.2h -1 0.3h -1 or 0.4h -1 The time can be 12~36 hours, specifically 12 hours, 16 hours, 20 hours, 24 hours, 30 hours, or 36 hours. This invention uses the acylhydrazone-based organic framework material as an adsorbent to remove metal and non-metal ions from distilled triethylamine based on multiple interactions such as coordination, electrostatics, and hydrogen bonding. Under the above conditions, this invention can effectively remove impurity ions from triethylamine, ultimately obtaining high-purity triethylamine. In one embodiment of this invention, the adsorption treatment can be carried out in a fixed bed, specifically by placing the adsorbent in a fixed bed and introducing the distilled triethylamine into the fixed bed for adsorption treatment.

[0047] The high-purity triethylamine prepared by the method of this invention has a total impurity content ≤0.3% and a total metal impurity content ≤1.5ppm. Specifically, the total impurity content and total metal impurity content in the high-purity triethylamine of this invention refer to mass content. The impurities in the high-purity triethylamine of this invention include both metallic and non-metallic impurities, and the non-metallic impurities include Cl. - N 4444 + One or more of water, ethanol, and diethylamine, and may further include Cl - and / or N 4444 + The metallic impurities may include Mn. 2+ Cu 2+ Cd 2+ Ni 2+ Fe 3+ Fe 2+Co 2+ Pt 4+ Ir 4+ and Ru 4+ One or more of them, and may further include Mn 2 + Cu 2+ Fe 3+ Fe 2+ Co 2+ Pt 4+ Ir 4+ and Ru 4+ One or more of them, wherein Mn 2+ Content ≤0.01ppm, Cu 2+ Content ≤0.51ppm, Fe 3+ and / or Fe 2+ Content ≤0.65ppm, Co 2+ Content ≤1.03 ppm, Pt 4+ Content ≤0.0ppm, Ir 4+ Content ≤0.01ppm, Ru 4+ Content ≤0.01ppm; N 4444 + Content ≤0.01ppm.

[0048] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0049] Preparation Example 1 The preparation of an ordered mesoporous SiO2 template includes the following steps: 18g of Pluronic® P-123 and 30mL of 12mol / L hydrochloric acid were added to 651mL of water and stirred at 35°C until completely dissolved. 18g of n-butanol was added, and the mixture was stirred at 35°C for 1 hour. Then, 38.7g of tetraethyl orthosilicate was added, and the mixture was stirred at 35°C for 24 hours. The mixture was then heated at 100°C for 24 hours under sealed conditions. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with ethanol. The washed filter cake was then heated from room temperature to 550°C at a rate of 1.5°C / min in air and calcined for 5 hours to obtain the ordered mesoporous SiO2 template with a specific surface area of ​​685m². 2 / g, with an average pore size of 7.7nm.

[0050] Preparation Example 2 The preparation of PtO2@CoMn2O4 supported porous composite transition metal oxide includes the following steps: (1) Mix 0.01341 mol Co(NO3)2·6H2O and 0.02682 mol Mn(NO3)2·4H2O with 20 mL of water to obtain a metal salt solution; mix 10 g of ordered mesoporous SiO2 template with 300 mL of n-hexane to obtain an ordered mesoporous SiO2 template dispersion; add 10 mL of metal salt solution to the ordered mesoporous SiO2 template dispersion under stirring (the mass ratio of the ordered mesoporous SiO2 template to the volume of the metal salt solution is 10 g: 10 mL), stir for 3 h at room temperature, filter, and obtain a solid; (2) The solid obtained in step (1) was placed in a muffle furnace at 700°C and calcined in air atmosphere for 2 hours to obtain the precursor; (3) The precursor obtained in step (2) was mixed with 600 mL of a 3 mol / L sodium hydroxide aqueous solution to remove the ordered mesoporous SiO2 template (the mass ratio of the ordered mesoporous SiO2 template to the volume ratio of the sodium hydroxide aqueous solution was 10 g: 600 mL). After filtration, a CoMn2O4 porous composite transition metal oxide with a specific surface area of ​​98 m² was obtained. 2 / g; (4) Mix 1.5g of Pt(NO3)2 with 10mL of water, stir and dissolve to obtain a platinum nitrate aqueous solution; take 10g of the CoMn2O4 porous composite transition metal oxide prepared in step (3) and add it to 10mL of platinum nitrate aqueous solution, stir at room temperature for 3h, filter, and then place the filter cake in an 800℃ muffle furnace and calcine in air atmosphere for 2h to obtain PtO2@CoMn2O4 supported porous composite transition metal oxide (denoted as PtO2@CoMn2O4), with a pore size of 50~100nm, a particle size of 300~400nm, and a specific surface area of ​​88m². 2 / g, with an active component PtO2 loading of 7.6wt%.

[0051] Preparation Example 3 The preparation of IrO2@CuMn2O4 supported porous composite transition metal oxides includes the following steps: (1) Mix 0.01341 mol Cu(NO3)2·6H2O and 0.02682 mol Mn(NO3)2·4H2O with 20 mL of water to obtain a metal salt solution; mix 10 g of ordered mesoporous SiO2 template with 300 mL of n-hexane to obtain an ordered mesoporous SiO2 template dispersion; add 10 mL of metal salt solution (the mass ratio of ordered mesoporous SiO2 template to metal salt solution is 10 g: 10 mL) to the ordered mesoporous SiO2 template dispersion under stirring conditions, stir for 3 h at room temperature, filter, and obtain a solid; (2) The solid obtained in step (1) was placed in a muffle furnace at 700°C and calcined in air atmosphere for 4 hours to obtain the precursor; (3) The precursor obtained in step (2) was mixed with 600 mL of a 3 mol / L sodium hydroxide aqueous solution to remove the ordered mesoporous SiO2 template (the mass ratio of the ordered mesoporous SiO2 template to the volume ratio of the sodium hydroxide aqueous solution was 10 g: 600 mL). After filtration, a CoMn2O4 porous composite transition metal oxide with a specific surface area of ​​180 m² was obtained. 2 / g; (4) Mix 1.7g of IrCl3·3H2O with 10mL of water, stir and dissolve to obtain an iridium chloride aqueous solution; take 10g of the CuMn2O4 porous composite transition metal oxide prepared in step (3) and add it to 10mL of iridium chloride aqueous solution, stir at room temperature for 3h, filter, and then place the filter cake in a muffle furnace at 700℃ and calcine in air atmosphere for 4h to obtain IrO2@CuMn2O4 supported porous composite transition metal oxide (denoted as IrO2@CuMn2O4), with a pore size of 5~50nm, a particle size of 200~300nm, and a specific surface area of ​​171m². 2 / g, with an active component IrO2 loading of 5.4wt%.

[0052] Preparation Example 4 The preparation of RuO2@CoFe2O4 supported porous composite transition metal oxide includes the following steps: (1) Mix 0.01341 mol Co(NO3)2·6H2O and 0.02682 mol Fe(NO3)3·9H2O with 20 mL of water to obtain a metal salt solution; mix 10 g of ordered mesoporous SiO2 template with 300 mL of n-hexane to obtain an ordered mesoporous SiO2 template dispersion; add 10 mL of metal salt solution (the mass ratio of ordered mesoporous SiO2 template to metal salt solution is 10 g: 10 mL) to the ordered mesoporous SiO2 template dispersion under stirring conditions, stir for 3 h at room temperature, filter, and obtain a solid; (2) The solid obtained in step (1) was placed in a muffle furnace at 850°C and calcined in air atmosphere for 6 hours to obtain the precursor; (3) The precursor obtained in step (2) was mixed with 600 mL of a 3 mol / L sodium hydroxide aqueous solution to remove the ordered mesoporous SiO2 template (the mass ratio of the ordered mesoporous SiO2 template to the volume ratio of the sodium hydroxide aqueous solution was 10 g: 600 mL). After filtration, a porous CoFe2O4 composite transition metal oxide with a specific surface area of ​​62 m² was obtained. 2 / g; (4) Mix 1.0 g of RuCl3 with 10 mL of water and stir to dissolve, obtaining an aqueous solution of ruthenium chloride; take 10 g of the porous composite transition metal oxide of CoFe2O4 prepared in step (3) and add it to 10 mL of the aqueous solution of ruthenium chloride, stir at room temperature for 3 h, filter, and then place the filter cake in a muffle furnace at 850 °C and calcine it in air atmosphere for 6 h to obtain RuO2@CoFe2O4 supported porous composite transition metal oxide (denoted as RuO2@CoFe2O4), with a pore size of 50~100 nm, a particle size of 400~500 nm, and a specific surface area of ​​50 m². 2 / g, with an active component RuO2 loading of 3.6wt%.

[0053] Preparation Example 5 The preparation of Tf-DHzOPr acylhydrazone-based organic framework materials includes the following steps: Weigh out 80.5 mg of triphenylformaldehyde, 237.8 mg of 2,5-dipropoxyterephthalamide (DHzOPr), and 305.0 mg of benzoic acid, mix them thoroughly, grind them completely, and then put them into a pressure-resistant bottle. After vacuuming, place the pressure-resistant bottle in an oven at 150°C for 2 days. After the reaction is completed, cool to room temperature and wash with N,N-dimethylformamide, acetone, and methanol in sequence, with each soaking and washing time being 3 hours. Then, extract with tetrahydrofuran by Soxhlet extraction for 48 hours, and then dry under vacuum at 80°C for 24 hours to obtain a light yellow powder, namely Tf-DHzOPr acylhydrazone organic framework material (denoted as Tf-DHzOPr), with a yield of 95%.

[0054] Figure 1 To prepare the N2 adsorption / desorption isotherms of the Tf-DHzOPr acylhydrazone organic framework material in Example 5, the results showed that the BET specific surface area of ​​the Tf-DHzOPr acylhydrazone organic framework material was 1158 m². 2 / g.

[0055] Figure 2 To prepare the pore size distribution map of the Tf-DHzOPr acylhydrazone organic framework material in Example 5, the results showed that the total pore volume of the Tf-DHzOPr acylhydrazone organic framework material was 0.58 cm³. 3 / g.

[0056] Figure 3 The XRD pattern of the Tf-DHzOPr acylhydrazone organic framework material in Example 5 was obtained. The results showed that the Tf-DHzOPr acylhydrazone organic framework material has an antiparallel structure and good crystallinity.

[0057] Preparation Example 6 The preparation of TFPB-DHzOPr acylhydrazone-based organic framework materials includes the following steps: 195.2 mg of 1,3,5-tris(p-formylphenyl)benzene, 232.5 mg of 2,5-dipropoxytetraphenylhydrazine (DHzOPr) and 377.5 mg of methyl 4-aminobenzoate were weighed, mixed thoroughly, and then placed in a pressure-resistant bottle. After vacuuming, the pressure-resistant bottle was placed in an oven at 150 °C for 3 days. After the reaction was completed, the mixture was cooled to room temperature and washed sequentially with N,N-dimethylformamide, acetone and methanol for 3 hours each time. Then, it was extracted with tetrahydrofuran by Soxhlet extraction for 48 hours and then dried under vacuum at 80 °C for 24 hours to obtain a light yellow powder, namely TFPB-DHzOPr acylhydrazone organic framework material (denoted as TFPB-DHzOPr), with a yield of 87%.

[0058] Figure 4 To prepare the N2 adsorption / desorption isotherms of the TFPB-DHzOPr acylhydrazone organic framework material in Example 6, the results showed that the BET specific surface area of ​​the TFPB-DHzOPr acylhydrazone organic framework material was 1849 m². 2 / g.

[0059] Figure 5 To prepare the pore size distribution map of the TFPB-DHzOPr acylhydrazone organic framework material in Example 6, the results showed that the total pore volume of the TFPB-DHzOPr acylhydrazone organic framework material was 1.23 cm³. 3 / g.

[0060] Figure 6 The XRD pattern of the TFPB-DHzOPr acylhydrazone organic framework material in Example 6 was prepared. The results showed that the TFPB-DHzOPr acylhydrazone organic framework material has an antiparallel structure and good crystallinity.

[0061] Preparation Example 7 The preparation of Tf-DHzOAll acylhydrazone-based organic framework materials includes the following steps: 80.5 mg of triphenylformaldehyde, 237.7 mg of 2,5-bis(allyloxy)terephthalohydrazide (DHzOAll) and 305.0 mg of benzoic acid were weighed, mixed thoroughly, and then placed in a pressure-resistant bottle. After vacuuming, the pressure-resistant bottle was placed in an oven at 150 °C for 2 days. After the reaction was completed, the mixture was cooled to room temperature and washed sequentially with N,N-dimethylformamide, acetone and methanol for 3 hours each time. Then, it was extracted with tetrahydrofuran by Soxhlet extraction for 48 hours and then dried under vacuum at 80 °C for 24 hours to obtain a light yellow powder, namely Tf-DHzOAll acylhydrazone organic framework material (denoted as Tf-DHzOAll), with a yield of 92%.

[0062] Test results show that the BET specific surface area of ​​the Tf-DHzOAll acylhydrazone-based organic framework material is 272 m². 2 / g, total pore volume is 0.22cm³ 3 / g, has an antiparallel structure and good crystallinity.

[0063] Preparation Example 8 The preparation of Tf-DHzOBn acylhydrazone-based organic framework materials includes the following steps: 80.5 mg of triphenylformaldehyde, 311.4 mg of 2,5-bis(benzyloxy)terephthalic acid (DHzOBn) and 305.0 mg of benzoic acid were weighed, mixed thoroughly, and then placed in a pressure-resistant bottle. After vacuuming, the pressure-resistant bottle was placed in an oven at 150 °C for 2 days. After the reaction was completed, the mixture was cooled to room temperature and washed sequentially with N,N-dimethylformamide, acetone and methanol for 3 hours each time. Then, it was extracted with tetrahydrofuran by Soxhlet extraction for 48 hours and then dried under vacuum at 80 °C for 24 hours to obtain a light yellow powder, namely Tf-DHzOBn acylhydrazone organic framework material (denoted as Tf-DHzOBn), with a yield of 94%.

[0064] Test results show that the BET specific surface area of ​​the Tf-DHzOBn acylhydrazone-based organic framework material is 216 m². 2 / g, total pore volume is 0.17cm³ 3 / g, has an antiparallel structure and good crystallinity.

[0065] Comparative Example 1 Activated carbon, purchased from Shanghai Titan Technology Co., Ltd., with a particle size of 200 mesh; test results show that the BET specific surface area of ​​the activated carbon is 1254 m². 2 / g, total pore volume is 0.79cm³ 3 / g.

[0066] Comparative Example 2 13X molecular sieve, purchased from Shanghai Titan Technology Co., Ltd., with a particle size of 80-100 mesh; test results show that the BET specific surface area of ​​the 13X molecular sieve is 245 m². 2 / g, total pore volume is 0.26cm³ 3 / g.

[0067] Test Example 1 The adsorption performance of the acylhydrazone-based organic framework materials obtained in Examples 5-8, as well as the activated carbon in Comparative Example 1 and the 13X molecular sieve in Comparative Example 2, for various ions was tested. The specific methods and conditions for testing the adsorption performance are as follows: (1) For Mn 2+Adsorption performance testing method: The acylhydrazone organic framework materials obtained in Preparation Examples 5-8, as well as the activated carbon in Comparative Example 1 and the 13X molecular sieve in Comparative Example 2, were activated under vacuum at 80℃ for 12h. 10mg of each material was weighed and added to four 50mL Erlenmeyer flasks, and then 5g of Mn was added to each flask. 2+ A triethylamine solution with a concentration of 42.98 ppm (prepared from Mn(NO3)2·4H2O, triethylamine, and water, wherein the water concentration is 2 wt%) was used. A sealed conical flask was placed in a shaker and shaken at 35°C for 24 hours. 2 g of the supernatant was taken and evaporated under vacuum. Then, 10 g of a solution with a concentration of 7.6 × 10⁻⁶ ppm was added. -2 M was dissolved in an aqueous nitric acid solution, and Mn was determined by ICP-OES. 2+ The concentration was determined, and the adsorption capacity and removal rate were calculated.

[0068] Figure 7 To prepare the acylhydrazone-based organic framework materials obtained in Examples 5-8, the reaction of Mn in triethylamine solution was carried out. 2+ Adsorption capacity and removal rate graph Figure 8 To prepare the acylhydrazone-based organic framework materials obtained in Examples 5-8, the adsorption of Mn from triethylamine solution before and after the adsorption was investigated. 2+ Concentration comparison graph. The results show that the acylhydrazone-based organic framework materials obtained in Preparation Examples 5-8 have a higher affinity for Mn. 2+ The adsorption capacities were 21.34 mg / g, 23.69 mg / g, 21.69 mg / g, and 21.74 mg / g, respectively; the Mn content in the triethylamine solution after adsorption was... 2+ The concentrations were 0.35 ppm, 0.04 ppm, 0.32 ppm, and 0.45 ppm, respectively, with removal rates of 99.19%, 99.91%, 99.26%, and 98.95%, respectively.

[0069] (2) For Cu 2+ Adsorption performance test method: The operation is the same as step (1), except that Cu(NO3)2·2.5H2O is used to provide Cu. 2 + .

[0070] (3) Regarding Cd 2+ Adsorption performance test method: The operation is the same as step (1), wherein Cd(NO3)2·4H2O is used to provide Cd. 2+ .

[0071] (4) For Ni 2+ Adsorption performance test method: The operation is the same as step (1), wherein Ni(NO3)2·6H2O is used to provide Ni. 2+ .

[0072] (5) For Fe 3+Adsorption performance test method: The operation is the same as step (1), wherein Fe(NO3)3·9H2O is used to provide Fe 3+ .

[0073] (6) For Fe 2+ Adsorption performance test method: The operation is the same as in step (1), except that Fe(NO3)2·7H2O is used to provide Fe. 2+ .

[0074] (7) For N 4444 + Adsorption performance testing method: The acylhydrazone organic framework materials obtained in Preparation Examples 5-8, the activated carbon in Comparative Example 1, and the 13X molecular sieve in Comparative Example 2 were activated under vacuum at 80℃ for 12h. 20mg of each material was weighed and added to four 50mL Erlenmeyer flasks, and then 10g of N was added to each flask. 4444 + A triethylamine solution with a concentration of 111.68 ppm (from [N 4444 The solution was prepared by mixing Cl, triethylamine, and water (the concentration of water was 2 wt%). The sealed conical flask was placed in a shaker and shaken at 35°C for 24 hours. 1 g of the supernatant was taken and evaporated under vacuum, then dissolved in 50 g of acetonitrile. N was determined by LC-MS. 4444 + The concentration was determined, and the adsorption capacity and removal rate were calculated.

[0075] Figure 9 To prepare the acylhydrazone-based organic framework materials obtained in Examples 5-8, the N in triethylamine solution... 4444 + Adsorption capacity and removal rate graphs. The results show that the acylhydrazone-based organic framework materials obtained in Examples 5-8 are effective against N2+. 4444 + The adsorption capacities were 50.39 mg / g, 51.32 mg / g, 52.79 mg / g, and 55.49 mg / g, respectively, and the removal rates were 99.51%, 99.94%, 97.72%, and 99.96%, respectively.

[0076] The performance test results are shown in Table 1, where "Qt" represents the adsorption amount at adsorption time t, "Qe" represents the equilibrium adsorption amount, and data without "Qe" in Table 1 are "Qt". As shown in Table 1, the acylhydrazone-based organic framework material of this invention, compared with existing commercial adsorbents such as activated carbon and molecular sieves, possesses functionalized adsorption sites and tunable pore structures, thus exhibiting significantly enhanced adsorption performance for various metal ions and organic cations. It can be used to remove impurities in the triethylamine system, achieving the preparation of high-purity triethylamine.

[0077] Table 1. Material performance test results in each embodiment and comparative example.

[0078] Example 1 Ethanol and liquid ammonia were mixed at a molar ratio of 0.5:1 and fed into a tubular fixed-bed reactor. After vaporization in a vaporization chamber located at the top of the reactor, vaporized gas was obtained. This vaporized gas, along with hydrogen, was then introduced into a catalyst bed containing PtO2@CoMn2O4 (from Preparation Example 2) within the reactor, wherein the volume hourly space velocity of the vaporized gas was 0.3 h⁻¹. -1 The volume hourly space velocity (VHSV) of hydrogen is 0.17 h⁻¹. -1 The pressure inside the reactor was controlled at 1.3 MPa by both vaporized gas and hydrogen, and the catalytic reaction was carried out at 140°C for 3 hours. The resulting product system was condensed to obtain an ethylamine mixture (containing monoethylamine, diethylamine, and triethylamine). The ethylamine mixture was then distilled to obtain distilled triethylamine with a yield of 65%. The distilled triethylamine was then passed into an adsorption bed containing TFPB-DHzOPr (from Preparation Example 6), and the volume hourly space velocity (VHSV) of the distilled triethylamine was controlled at 0.3 h⁻¹. -1 The product was obtained by adsorption treatment at 25℃ for 12 hours to obtain high-purity triethylamine.

[0079] Table 2 shows the types and contents of metal impurities in the ethylamine mixture, distilled triethylamine, and triethylamine products of Example 1, and their N content. 4444 + The results showed that the triethylamine product prepared by the method of the present invention had a low content of metal impurities.

[0080] Table 2. Types and contents of impurities in the ethylamine mixture, distilled triethylamine, and triethylamine products from Example 1.

[0081] Example 2 Ethanol and liquid ammonia were mixed at a molar ratio of 0.5:1 and fed into a tubular fixed-bed reactor. After vaporization in a vaporization chamber located at the top of the reactor, vaporized gas was obtained. This vaporized gas, along with hydrogen, was then introduced into a catalyst bed containing IrO2@CuMn2O4 (from Preparation Example 3) within the reactor, wherein the volume hourly space velocity of the vaporized gas was 0.3 h⁻¹. -1 The volume hourly space velocity (VHSV) of hydrogen is 0.17 h⁻¹. -1 The pressure inside the reactor was controlled at 1.3 MPa by both vaporized gas and hydrogen, and the catalytic reaction was carried out at 140°C for 3 hours. The resulting product system was condensed to obtain an ethylamine mixture (containing monoethylamine, diethylamine, and triethylamine). The ethylamine mixture was then distilled to obtain distilled triethylamine with a yield of 74%. The distilled triethylamine was then passed into an adsorption bed containing Tf-DHzOAll (from Preparation Example 7), and the volume hourly space velocity (VHSV) of the distilled triethylamine was controlled at 0.3 h⁻¹. -1The product was obtained by adsorption treatment at 45℃ for 24 hours.

[0082] Table 3 shows the types and contents of metal impurities in the ethylamine mixture, distilled triethylamine, and triethylamine products of Example 2, and the N content. 4444 + The results showed that the triethylamine product prepared by the method of the present invention had a low content of metal impurities.

[0083] Table 3. Types and contents of impurities in the ethylamine mixture, distilled triethylamine, and triethylamine products from Example 2.

[0084] Example 3 Ethanol and liquid ammonia were mixed at a molar ratio of 0.5:1 and fed into a tubular fixed-bed reactor. After vaporization in a vaporization chamber located at the top of the reactor, vaporized gas was obtained. This vaporized gas, along with hydrogen, was then introduced into a catalyst bed containing RuO2@CoFe2O4 (from Preparation Example 4) within the reactor, wherein the volume hourly space velocity of the vaporized gas was 0.3 h⁻¹. -1 The volume hourly space velocity (VHSV) of hydrogen is 0.17 h⁻¹. -1 The pressure inside the reactor was controlled at 1.3 MPa by both vaporized gas and hydrogen, and the catalytic reaction was carried out at 140°C for 3 hours. The resulting product system was condensed to obtain an ethylamine mixture (containing monoethylamine, diethylamine, and triethylamine). The ethylamine mixture was then distilled to obtain distilled triethylamine with a yield of 51%. The distilled triethylamine was then passed into an adsorption bed containing Tf-DHzOBn (from Preparation Example 8), and the volume hourly space velocity (VHSV) of the distilled triethylamine was controlled at 0.3 h⁻¹. -1 The product was obtained by adsorption treatment at 60℃ for 36 hours to obtain high-purity triethylamine.

[0085] Table 4 shows the types and contents of metal impurities in the ethylamine mixture, distilled triethylamine, and triethylamine products of Example 3, and their N content. 4444 + The results showed that the triethylamine product prepared by the method of the present invention had a low content of metal impurities.

[0086] Table 4. Types and contents of impurities in the ethylamine mixture, distilled triethylamine, and triethylamine products from Example 3.

[0087] Test Example 2 The results of Examples 1-3 above show that the acylhydrazone-based organic framework material provided by the present invention has excellent adsorption effect on ppm-level impurities. Based on this, this test example further reduces the initial concentration of impurities and performs static adsorption on ppb-level impurities. The specific steps are as follows: The acylhydrazone-based organic framework material obtained in Preparation Example 5 was activated under vacuum at 80℃ for 12 h. 400 mg of the activated acylhydrazone was weighed and added to a 500 mL blue-capped bottle, followed by 200 g of triethylamine solution (prepared from CuCl2·2H2O, FeCl3, ZnCl2, NiCl2·2H2O, Pb(NO3)2, and triethylamine). The mass content of each ion is shown in Table 5. The sealed blue-capped bottle was placed in a shaker and shaken at 35℃ for 24 h. The concentration of metal ions was determined by ICP-OES / MS before and after adsorption, and the concentration of chloride ions was determined by ion chromatography. Table 5 shows the concentrations of each ion before and after adsorption. The results show that the acylhydrazone-based organic framework material of this invention can effectively adsorb ppb-level impurity ions in the triethylamine solution.

[0088] Table 5. Ion concentrations before and after adsorption

[0089] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing high-purity triethylamine, characterized in that, Includes the following steps: Ammonia and ethanol are catalytically reacted in the presence of a catalyst and hydrogen to produce a mixture of ethylamine. The ethylamine mixture was subjected to distillation to obtain distilled triethylamine; The distilled triethylamine was subjected to adsorption treatment with an adsorbent to obtain high-purity triethylamine, wherein the total impurity content of the high-purity triethylamine is ≤0.3% and the total metal impurity content is ≤1.5ppm; The catalyst is a porous composite transition metal oxide; The adsorbent is an acylhydrazone organic framework material, which is obtained by polymerization of raw materials including aldehyde monomers and acylhydrazine monomers. The aldehyde monomer has the structure shown in Formula II-1, Formula II-2 or Formula II-3: Formula II-1; Formula II-2; Formula II-3; The hydrazide monomer has the structure shown in Formula III-1, Formula III-2 or Formula III-3: Formula III-1; Formula III-2; Formula III-3; The R is selected from methylene, nitrogen atom, phenyl or triazine group; R1 is selected from propyl, allyl, benzyl, or... N,N -Dimethylethylamino; R2 is selected from methine, nitrogen atom, phenyl or triazine group.

2. The preparation method according to claim 1, characterized in that, The aldehyde monomer is triphenylformaldehyde and the hydrazide monomer is 2,5-dipropoxyterephthalic acid hydrazide; Alternatively, the aldehyde monomer is 1,3,5-tris(p-formylphenyl)benzene and the hydrazide monomer is 2,5-dipropoxy-p-phenylhydrazide; Alternatively, the aldehyde monomer is triphenylaldehyde and the hydrazide monomer is 2,5-bis(allyloxy)terephthalohydrazide; Alternatively, the aldehyde monomer is triphenylformaldehyde and the acylhydrazine monomer is 2,5-bis(benzyloxy)terephthalic acid hydrazine.

3. The preparation method according to claim 1, characterized in that, The porous composite transition metal oxide includes an XY2O4 type porous matrix material and an active component supported on the surface of the XY2O4 type porous matrix material; X is selected from Co or Cu, Y is selected from Mn or Fe, and the active component is selected from one or more of PtO2, IrO2 and RuO2.

4. The preparation method according to claim 3, characterized in that, The content of the active component in the porous composite transition metal oxide is 0.5~10wt%.

5. The preparation method according to claim 3 or 4, characterized in that, The porous composite transition metal oxide has a pore size of 5-100 nm, a particle size of 200-500 nm, and a specific surface area of ​​50-200 m². 2 / g.

6. The preparation method according to claim 1, characterized in that, The molar ratio of ethanol to ammonia is 0.5 to 3:

1.

7. The preparation method according to claim 1 or 6, characterized in that, The conditions for the catalytic reaction include: a temperature of 120–160 °C, a pressure of 0.6–1.8 MPa, and a total volume hourly space velocity (VHSV) of 0.1–0.4 h⁻¹ for ammonia and ethanol. -1 .

8. The preparation method according to claim 1, characterized in that, The conditions for the adsorption treatment include: a temperature of 25–60°C and a volume hourly space velocity (VHSV) of 0.1–0.4 h⁻¹ for the distillation of triethylamine. -1 .

9. The preparation method according to claim 1, characterized in that, The high-purity triethylamine contains impurities including metallic impurities and non-metallic impurities, the non-metallic impurities including Cl. - Et4N + One or more of water, ethanol and diethylamine.

10. The preparation method according to claim 1 or 9, characterized in that, The metallic impurities include Mn. 2+ Cu 2+ Cd 2 + Ni 2+ Fe 3+ Fe 2+ Co 2+ Pt 4+ Ir 4+ and Ru 4+ One or more of them.

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