A method for directly preparing ethylene glycol from ethylene by using a metal composite ceramic membrane for separation

Abstract

This invention relates to the field of ethylene glycol preparation, specifically to a method for the direct production of ethylene glycol from ethylene. The method includes: reacting ethylene with hydrogen peroxide in the presence of an oxidative hydration bifunctional catalyst to obtain a material containing ethylene glycol, and collecting the product after separation via a metal-ceramic composite membrane. Using this method, ethylene glycol can be produced in a one-step process. The reaction exhibits high hydrogen peroxide utilization, ethylene conversion rate, and ethylene glycol selectivity, along with high catalyst activity and stability. During separation, the transmembrane pressure difference is small, allowing the separation system to operate continuously for extended periods. The resulting product liquid has a low catalyst concentration.

Description

Technical Field

[0001] This invention relates to the field of ethylene glycol preparation, and more specifically to a method for the direct production of ethylene glycol from ethylene using a metal-ceramic membrane separation process. Background Technology

[0002] Ethylene can be oxidized and hydrated to produce ethylene glycol. The system resulting from the reaction of ethylene and hydrogen peroxide is a liquid-solid system, which needs to be separated, and the catalyst can be reused. Common separation methods include centrifugation, precipitation, filtration, and sedimentation. Among filtration separation methods, membrane separation technology has advantages such as high efficiency and energy saving, no phase change, room temperature operation, small footprint, ease of operation, and good stability. However, the metal membranes currently used in the market have the problem of difficulty in improving filtration accuracy, while ceramic membranes have the problems of high brittleness and low thermal shock resistance. Therefore, the separation effect still needs to be further improved.

[0003] In addition, during the reaction stage, the current production route (EOEG route) mainly suffers from problems such as easy oxidation of intermediate products, significant safety hazards, low product selectivity, environmental unfriendliness, and high cost. Current research has found that using titanium silicate molecular sieves can achieve one-step preparation of ethylene glycol from ethylene, which can achieve safe production, reduce energy consumption, and be environmentally friendly, but has not yet been industrialized. Summary of the Invention

[0004] The purpose of this invention is to provide a method for the direct production of ethylene glycol from ethylene using a metal-ceramic membrane separation process. This method features a small transmembrane pressure difference, long-term operation of the separation system, and low catalyst concentration in the separated product liquid. Using this method, ethylene glycol can be produced in a one-step process. In the reaction, the catalyst of this invention exhibits high hydrogen peroxide utilization, high ethylene conversion rate, and high ethylene glycol selectivity, as well as high catalyst activity stability.

[0005] This invention provides a method for the direct production of ethylene glycol from ethylene using a metal-composite ceramic membrane. The method includes: reacting ethylene with hydrogen peroxide in the presence of an oxidative hydration bifunctional catalyst to obtain a material containing ethylene glycol, and collecting the product after separation by a metal-composite ceramic membrane.

[0006] In this invention, there are no special requirements for the specific structure of the metal-ceramic composite membrane. According to a preferred embodiment of the invention, the metal-ceramic composite membrane sequentially comprises a base layer, a transition layer, and a precision membrane layer. The base layer is made of a metal material, the transition layer is made of a ceramic material and / or a metal material, and the precision membrane layer is made of a ceramic material. The material to be separated comes into contact with the precision membrane layer for separation. Any metal-ceramic composite membrane that meets the foregoing requirements can achieve the purpose of this invention. For details, please refer to the metal-ceramic composite membranes described in CN110252156B and CN110252157B, which are also incorporated herein by reference.

[0007] According to a preferred embodiment of the present invention, the average pore size of the precision membrane layer is 5-100 nm (i.e., separation accuracy). Using the aforementioned technical solution, the catalyst concentration in the separated product liquid can be lower, and less catalyst loss can be achieved. In metal-ceramic composite membranes, the average pore size of the precision membrane layer represents the separation accuracy of the metal-ceramic composite membrane.

[0008] This invention is the first to use a metal-ceramic membrane for separation in a method for the direct production of ethylene glycol from ethylene. During the separation process, the transmembrane pressure difference is small, and the separation system can achieve long-term operation. The catalyst concentration in the separated product liquid is low, and the catalyst loss in the reactants is small.

[0009] In this invention, there is no particular limitation on the amount of ethylene and hydrogen peroxide used in the contact reaction of ethylene and hydrogen peroxide. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the molar ratio of ethylene to hydrogen peroxide is 1-2:1.

[0010] In this invention, hydrogen peroxide is provided by an aqueous solution of hydrogen peroxide.

[0011] In this invention, there are no special requirements for the temperature of the reaction. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the reaction temperature is 20-90°C.

[0012] In this invention, there are no special requirements for the pressure of the reaction. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the pressure of the reaction is 0.1-3 MPa.

[0013] In this invention, there are no special requirements regarding the specific type of the oxidation-hydration bifunctional catalyst; commonly used oxidation-hydration bifunctional catalysts can all be used in this invention. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the oxidation-hydration bifunctional catalyst is a modified MFI structure titanium-silicon molecular sieve, and the specific surface area of ​​this molecular sieve is ≥350 m².2 / g, total pore volume ≥0.2cm³ 3 / g, micropore volume ≥0.12cm³ 3 / g, mesopore volume ≥0.15cm³ 3 / g, the amount of acid with an acid strength H0 ≤ +3.85 is above 0.05 n-butylamine / g molecular sieve, and the amount of acid with an acid strength H0 ≤ +4.8 is above 0.60 n-butylamine / g molecular sieve; the vanadium-titanium molar ratio of the molecular sieve is 0.01-0.4:1 (elementally). Modified MFI structure titanium-silicon molecular sieves are used in the ethylene oxidation hydration to ethylene glycol reaction. The molecular sieve exhibits good dispersion performance in aqueous systems, is not prone to sedimentation, has a large specific surface area, high hydrogen peroxide utilization rate, high ethylene conversion rate, and high ethylene glycol selectivity, and high activity stability.

[0014] According to a preferred embodiment of the present invention, the molar ratio of titanium to silicon in the modified MFI structured titanium-silicon molecular sieve is 0.01-0.1:1, based on oxides; preferably 0.03-0.08:1.

[0015] In this invention, the modified MFI structure titanium-silicon molecular sieve with a vanadium-titanium molar ratio of 0.03-0.1:1 has superior catalytic performance.

[0016] In this invention, the specific surface area is satisfied to be 950-1500 cm². 3 The molecular sieve with / g exhibits superior catalytic performance.

[0017] In this invention, the total pore volume is satisfied to be 0.3-0.7 cm³. 3 The molecular sieve with / g exhibits superior catalytic performance.

[0018] In this invention, the micropore volume is satisfied to be 0.15-0.28 cm³. 3 The molecular sieve with / g exhibits superior catalytic performance.

[0019] In this invention, the mesopore volume is satisfied to be 0.2-0.6 cm³. 3 The molecular sieve with / g exhibits superior catalytic performance.

[0020] In this invention, the molecular sieve with an acid content of 0.07-0.1 n-butylamine / gram molecular sieve that satisfies the acid strength H0≤+3.85 has better catalytic performance.

[0021] In this invention, the molecular sieve with an acid content of 0.7-0.9 n-butylamine / gram molecular sieve that satisfies the acid strength H0≤+4.8 has better catalytic performance.

[0022] In this invention, there are no special requirements for the preparation method of the oxidation-hydration bifunctional catalyst. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the preparation method of the oxidation-hydration bifunctional catalyst includes: mixing MFI structured titanium-silicon molecular sieve, surfactant, organovanadium ester and water, performing solid-liquid separation, drying and calcining to obtain modified MFI structured titanium-silicon molecular sieve; wherein, the surfactant is selected from one or more of cationic surfactant, anionic surfactant and nonionic surfactant; the weight ratio of the surfactant to the titanium-silicon molecular sieve is not less than 0.005; and the molar ratio of organovanadium ester to MFI structured titanium-silicon molecular sieve is 0.01-0.4:1.

[0023] In this invention, there is no particular limitation on the molar ratio of titanium to silicon in the MFI structure titanium-silicon molecular sieve used in the preparation of the oxidative hydration bifunctional catalyst. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the molar ratio of titanium to silicon in the MFI structure titanium-silicon molecular sieve, based on oxides, is 0.01-0.1:1, preferably 0.03-0.08:1.

[0024] In this invention, the specific types of the organovanadium ester can be selected from a wide range. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the organovanadium ester is selected from one or more of vanadium acetylacetonate, vanadium oxalate, and vanadium acetylacetonate, preferably vanadium oxalate.

[0025] In this invention, there are no special requirements for the mixing order of the MFI structured titanium-silicon molecular sieve, surfactant, organovanadium ester and water. As long as each material is fully mixed, it is acceptable. In this invention, the MFI structured titanium-silicon molecular sieve, surfactant and water are mixed first, and then the organovanadium ester is added, but this does not limit the scope of this invention.

[0026] In this invention, the range of anionic surfactants is relatively wide. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the anionic surfactant is selected from one or more of alkylbenzene sulfonates, alkyl sulfonates, and alkyl sulfonates, and is more preferably one or more of sodium dodecylbenzene sulfonate, sodium α-alkenyl sulfonate, and sodium secondary alkyl sulfonate.

[0027] In this invention, a wide range of cationic surfactants can be selected. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the cationic surfactant is selected from one or more of hexadecyltrimethylammonium chloride and octadecyltrimethylammonium chloride.

[0028] In this invention, the range of nonionic surfactants is relatively wide. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the nonionic surfactant is selected from one or more of fatty alcohol polyoxyethylene ether, alkyl alcohol amide, polyol monofatty acid ester, alkyl amine oxide, and N-alkylpyrrolidone, preferably one or more of sorbitan stearate, dehydrated sorbitan monooleate polyoxyethylene ether, polysorbate fatty acid ester-60, and (Z)-mono-9-octadecenoic acid dehydrated sorbitan ester.

[0029] According to a preferred embodiment of the present invention, the surfactant is a mixture of cationic surfactant and nonionic surfactant, wherein the content of each of the cationic surfactant and nonionic surfactant is not less than 25% and preferably not less than 40% based on the total weight of the surfactant.

[0030] According to a particularly preferred embodiment of the present invention, the surfactant is a mixture of hexadecyltrimethylammonium chloride and (Z)-mono-9-octadecenoic acid dehydrated sorbitol ester, wherein the content of each of the hexadecyltrimethylammonium chloride and (Z)-mono-9-octadecenoic acid dehydrated sorbitol ester is not less than 40% based on the total weight of the surfactant. The catalyst prepared using the aforementioned technical solution has superior catalytic performance.

[0031] According to a preferred embodiment of the present invention, the weight ratio of the surfactant to the titanium silicate molecular sieve is 0.005-0.1:1, preferably 0.01-0.1:1.

[0032] In this invention, there are no special requirements regarding the order in which the molecular sieve, surfactant, and water are added.

[0033] In this invention, there is no particular limitation on the ratio of water to titanium-silicon molecular sieve. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the weight ratio of water to titanium-silicon molecular sieve is 2-50:1, preferably 10-30:1.

[0034] According to a preferred embodiment of the present invention, the molar ratio of organovanadium ester to MFI-structured titanium-silicon molecular sieve is 0.03-0.1:1. The molecular sieve prepared using the aforementioned technical solution exhibits superior catalytic performance.

[0035] In this invention, the mixing temperature can be selected over a wide range. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the mixing temperature is 130-260°C, preferably 170-230°C.

[0036] In this invention, there is no particular limitation on the mixing time. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the mixing time is 1-72 hours, preferably 5-48 hours.

[0037] In this invention, there are no special requirements for the specific type of the MFI structured titanium-silicon molecular sieve; it can be TS-1, TS-2, or a laboratory-made TS-S. According to a preferred embodiment of this invention, the preparation method of TS-S includes: mixing a silicon source, a titanium source, a template agent, a surfactant, and water; heating the reaction; separating the solid and liquid phases; drying; and calcining. The heating reaction includes a first-stage reaction, a second-stage reaction, and a third-stage reaction. The conditions for the heating reaction include: a first-stage reaction temperature of 20-50℃; and / or a first-stage reaction time of 0.5-3.5 h; a second-stage reaction temperature of 70-100℃; and / or a second-stage reaction time of 0.5-3.5 h; a third-stage reaction temperature of 130-190℃; and / or a third-stage reaction time of 10-80 h.

[0038] In this invention, a three-stage reaction is adopted in the preparation of TS-S. First, the hydrolysis temperature and time of silicon and titanium sources in the presence of surfactant are controlled to allow for appropriate hydrolysis and condensation, producing an appropriate amount of monohydroxy silicon and titanium species. Then, the temperature is increased so that these silicon-titanium hydroxy species gradually form silicon-titanium hydroxyl nests under the action of surfactant. Then, the temperature is increased and the time is controlled for hydrothermal crystallization until TS-S with suitable acidity is synthesized.

[0039] In this invention, there are no special requirements for the heating rate of the heating reaction.

[0040] In this invention, there are no special requirements for the type of silicon source used in the TS-S preparation process. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the silicon source is selected from organosilicone esters, preferably one or more of methyl silicate, ethyl silicate, propyl silicate, and butyl silicate.

[0041] In this invention, there is no particular limitation on the type of titanium source used in the TS-S preparation process. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the titanium source is selected from organic titanate esters, preferably one or more of methyl titanate, ethyl titanate, propyl titanate, and butyl titanate.

[0042] In this invention, the range of template agents that can be selected in the TS-S preparation process is relatively wide. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the template agent is selected from one or more of tetramethylammonium hydroxide, tetramethylammonium bromide, tetraethylammonium hydroxide, tetraethylammonium bromide, tetrapropylammonium hydroxide, tetrapropylammonium bromide, tetrabutylammonium hydroxide, and tetrabutylammonium bromide.

[0043] In this invention, the range of surfactants that can be selected in the TS-S preparation process is relatively wide. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the surfactant is selected from one or more of cationic surfactants, anionic surfactants, and nonionic surfactants. The anionic surfactant is selected from one or more of alkylbenzene sulfonates, alkyl sulfonates, and alkyl sulfonates, preferably one or more of sodium dodecylbenzene sulfonate, sodium α-alkenyl sulfonate, and sodium secondary alkyl sulfonate. The cationic surfactant is selected from one or more of hexadecyltrimethylammonium chloride and octadecyltrimethylammonium chloride. The surfactant is selected from one or more of fatty alcohol polyoxyethylene ethers, alkylolamides, polyol monofatty acid esters, alkylamine oxides, and N-alkylpyrrolidones, preferably one or more of sorbitan stearate, dehydrated sorbitan monooleate polyoxyethylene ether, polysorbate fatty acid ester-60, and (Z)-mono-9-octadecenoic acid dehydrated sorbitan ester.

[0044] In this invention, there is no particular limitation on the amount of each material used in the TS-S preparation process. According to a preferred embodiment of this invention, in the preparation process, the molar ratio of silicon source (calculated as oxide), titanium source (calculated as oxide), template agent, surfactant and water is 1:(0.01-0.1):(0.03-0.2):(0.0001-0.002):(5-80), preferably 1:(0.03-0.008):(0.08-0.15):(0.0005-0.001):(10-40).

[0045] In this invention, there are no special requirements for the solid-liquid separation, drying, and calcination operating conditions, which are well known to those skilled in the art and will not be described in detail here.

[0046] The present invention will be described in detail below through embodiments.

[0047] In the following embodiments, Specific surface area was measured using the low-temperature nitrogen adsorption method; The total orifice volume was measured using the static volumetric method. The micropore volume was measured using the gas adsorption method; The mesopore volume was measured using the gas adsorption method; The amount of acid with an acid strength ≤ +3.85 and the amount of acid with an acid strength ≤ +4.8 were characterized by Hammett indicator titration. The titanium-silicon molar ratio of the molecular sieve can be calculated based on the amount of material fed. Ethylene conversion rate calculation formula: Ethylene conversion rate % = (number of moles of ethylene added - number of moles of ethylene remaining) / number of moles of ethylene added * 100%; Formula for calculating hydrogen peroxide utilization rate: H2O2 effective utilization rate % = number of moles of ethylene glycol / (number of moles of H2O2 added - number of moles of remaining H2O2) * 100%; Formula for calculating ethylene glycol selectivity: Ethylene glycol selectivity % = (moles of ethylene glycol / (moles of ethylene glycol + moles of diethylene glycol + moles of triethylene glycol)) * 100%; Ethylene glycol, diethylene glycol, and triethylene glycol were analyzed using an Agilent 7890A gas chromatograph with an FID detector, while hydrogen peroxide was analyzed using an Agilent 1200 series high-performance liquid chromatograph.

[0048] The probe reaction of TS-1 showed a phenol hydroxylation activity of 23%. The probe reaction of TS-2 showed a phenol hydroxylation activity of 25%. The dehydrated sorbitan monooleate polyoxyethylene ether is a commercially available product, model T-20, manufactured by Jinan Xiangfeng Weiye Chemical Co., Ltd.

[0049] The transmembrane pressure difference is calculated by subtracting the filtrate pressure from the average membrane inlet and outlet pressures. The catalyst concentration in the product solution is obtained by dividing the mass of the catalyst obtained after drying and calcining the product solution by the volume of the product solution.

[0050] The technical solution of this invention uses a metal-ceramic composite membrane in the separation process, which can result in a small transmembrane pressure difference (0.01-2.00MPa) and enable the separation system to operate for a long period of time; the catalyst concentration in the separated product liquid is low (<40ppm) and the catalyst loss in the reactants is small.

[0051] In a preferred embodiment, the catalyst of the present invention enables the one-step production of ethylene glycol from ethylene. During the reaction, the utilization rate of hydrogen peroxide, the conversion rate of ethylene, and the selectivity of ethylene glycol are high, and the catalyst activity and stability are high. Detailed Implementation

[0052] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0053] In the following examples, the reaction conditions were: catalyst mass concentration of 10%, reaction temperature of 20°C, and reaction pressure of 1 MPa.

[0054] The preparation methods of the metal film and ceramic film used in the following comparative examples are mature existing technologies and will not be described in detail.

[0055] Preparation Example 1 (1) Ethyl silicate (calculated as oxide), propyl silicate (calculated as oxide), propyl titanate (calculated as oxide), tetrapropylammonium hydroxide, hexadecyltrimethylammonium chloride and water were added to a stirred reactor in a molar ratio of 0.6:0.4:0.03:0.2:0.0006:25. The reaction was carried out at 45°C for 1 h, then the temperature was increased to 85°C and the reaction was carried out for 0.5 h. Then the temperature was increased to 180°C and the reaction was carried out for 24 h. After that, the mixture was filtered, dried and calcined to obtain titanium silicon molecular sieve TS-S-1 (titanium silicon molar ratio of 0.03:1). (2) TS-S-1, polysorbate fatty acid ester-60, sodium dodecylbenzenesulfonate, and water were mixed in a weight ratio of 1:0.02:0.05:8. Then, vanadium oxalate was added so that the ratio of vanadium oxalate to TS-S-1 (based on the molar ratio of vanadium and titanium) was 0.1:1. The mixture was stirred at 135°C for 72 hours, then filtered, dried, and calcined to obtain a modified titanium-silicon molecular sieve, denoted as TS-S-1'. The specific surface area of ​​this molecular sieve was 1285 m². 2 / g; Total pore volume is 0.43cm³ 3 / g; micropore volume is 0.19cm³ 3 / g; mesopore volume is 0.24cm³ 3 / g; the amount of acid with an acid strength H0 ≤ +3.85 characterized by Hammett indicator titration is 0.085 n-butylamine / g molecular sieve; the amount of acid with an acid strength H0 ≤ +4.8 is 0.83 n-butylamine / g molecular sieve, and the vanadium-titanium molar ratio is 0.1:1.

[0056] Preparation Example 2 (1) Ethyl silicate (calculated as oxide), ethyl titanate (calculated as oxide), butyl titanate (calculated as oxide), tetraethylammonium hydroxide, tetramethylammonium bromide, and sorbitan stearate were added to a stirred reactor in a molar ratio of 1:0.05:0.06:0.08:0.001:75. The mixture was reacted at 25°C for 3 hours, then the temperature was increased to 75°C for 1.5 hours, and then the temperature was increased to 160°C for 40 hours. The mixture was then filtered, dried, and calcined to obtain a titanium-silicon molecular sieve, designated as TS-S-2 (titanium-silicon molar ratio of 0.11:1). (2) TS-S-2, octadecyltrimethylammonium chloride and water were mixed in a weight ratio of 1:0.05:30. Then, vanadium acetylacetonate was added so that the ratio of vanadium acetylacetonate to TS-S-2 (based on the molar amount of vanadium and titanium) was 0.1:1. The mixture was stirred at 220°C for 24 hours, then filtered, dried and calcined to obtain a modified titanium-silicon molecular sieve, denoted as TS-S-2', with a specific surface area of ​​1328 m². 2 / g; total pore volume is 0.52cm³. 3 / g; micropore volume is 0.26cm³ 3 / g; mesopore volume is 0.26cm³ 3 / g; the amount of acid with an acid strength H0 ≤ +3.85 characterized by Hammett indicator titration is 0.079 n-butylamine / g molecular sieve; the amount of acid with an acid strength H0 ≤ +4.8 is 0.81 n-butylamine / g molecular sieve, and the vanadium-titanium molar ratio is 0.1:1.

[0057] Preparation Example 3 (2) Butyl silicate (calculated as oxide), ethyl titanate (calculated as oxide), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, sorbitan monooleate polyoxyethylene ether and water were added to a stirred reactor in a molar ratio of 1:0.08:0.05:0.07:0.0008:40 and reacted at 35°C for 2.5 h. Then the temperature was increased to 80°C and reacted for 2.5 h. Then the temperature was increased to 130°C and reacted for 80 h. After that, the mixture was filtered, dried and calcined to obtain titanium silicon molecular sieve TS-S-3 (titanium silicon molar ratio of 0.08:1). (2) TS-S-3, (Z)-mono-9-octadecenoic acid dehydrated sorbitol ester, hexadecyltrimethylammonium chloride and water were mixed in a weight ratio of 1:0.05:0.05:10. Then, acetylacetone vanadium oxide was added so that the ratio of acetylacetone vanadium oxide to TS-S-3 (based on the molar amount of vanadium and titanium) was 0.1:1. The mixture was stirred at 180°C for 48 h, then filtered, dried and calcined to obtain a modified titanium-silicon molecular sieve, denoted as TS-S-3', with a specific surface area of ​​1486 m². 2 / g; Total pore volume is 0.58cm³ 3 / g; micropore volume is 0.27cm³ 3 / g; mesopore volume is 0.31cm³ 3 / g; Hammett indicator 4-reagent titration method characterization of acid strength H0≤+3.85 acid amount is 0.088 n-butylamine / g molecular sieve; acid strength H0≤+4.8 acid amount is 0.89 n-butylamine / g molecular sieve, vanadium-titanium molar ratio is 0.1:1.

[0058] Preparation Example 4 Titanium silicate molecular sieve TS-1 (titanium silicate molar ratio of 0.03, phenol hydroxylation activity of 23% in probe reaction), (Z)-mono-9-octadecenoic acid dehydrated sorbitol ester, hexadecyltrimethylammonium chloride, and water were mixed in a weight ratio of 1:0.05:0.05:10. Then, vanadium oxalate was added to make the ratio of vanadium oxalate to TS-1 (based on the molar ratio of vanadium and titanium) 0.1:1. The mixture was stirred at 180℃ for 48 h, followed by filtration, drying, and calcination to obtain a modified titanium silicate molecular sieve, denoted as TS-1', with a specific surface area of ​​951 m². 2 / g; Total pore volume is 0.31cm³ 3 / g; micropore volume is 0.17cm³ 3 / g; mesopore volume is 0.14cm³ 3 / g; the amount of acid with an acid strength H0 ≤ +3.85 characterized by Hammett indicator titration is 0.051 n-butylamine / g molecular sieve; the amount of acid with an acid strength H0 ≤ +4.8 is 0.61 n-butylamine / g molecular sieve, and the vanadium-titanium molar ratio is 0.1:1.

[0059] Preparation Example 5 Titanium silicate molecular sieve TS-2 (titanium silicate molar ratio of 0.03, phenol hydroxylation activity of 25% in probe reaction), (Z)-mono-9-octadecenoic acid dehydrated sorbitol ester, hexadecyltrimethylammonium chloride, and water were mixed in a weight ratio of 1:0.05:0.05:10. Then, vanadium oxalate was added so that the ratio of vanadium oxalate to TS-2 (based on the molar ratio of vanadium and titanium) was 0.1:1. The mixture was stirred at 180℃ for 48 h, followed by filtration, drying, and calcination to obtain the modified titanium silicate molecular sieve denoted as TS-2', with a specific surface area of ​​1026 m². 2 / g; Total pore volume is 0.38cm³ 3 / g; micropore volume is 0.18cm³ 3 / g; mesopore volume is 0.20cm³ 3 / g; the amount of acid with an acid strength H0 ≤ +3.85 characterized by Hammett indicator titration is 0.053 n-butylamine / g molecular sieve; the amount of acid with an acid strength H0 ≤ +4.8 is 0.64 n-butylamine / g molecular sieve, and the vanadium-titanium molar ratio is 0.1:1.

[0060] Preparation Example 6 Following the method of Preparation Example 3, except that in step (2), the organovanadium ester used is vanadium oxalate, and the resulting modified titanium silicate molecular sieve is designated as TS-S-4', with a specific surface area of ​​1492 m². 2 / g; Total pore volume is 0.61cm³ 3 / g; micropore volume is 0.24cm³ 3 / g; mesopore volume is 0.33cm³ 3 / g; the amount of acid with an acid strength H0 ≤ +3.85 characterized by Hammett indicator titration is 0.094 n-butylamine / g molecular sieve; the amount of acid with an acid strength H0 ≤ +4.8 is 0.9 n-butylamine / g molecular sieve, and the vanadium-titanium molar ratio is 0.1:1.

[0061] Preparation Example 7 The method of Preparation Example 2 is the same, except that in step (2), the surfactant is a mixture of (Z)-mono-9-octadecenoic acid dehydrated sorbitan ester and hexadecyltrimethylammonium chloride, and TS-S-2, (Z)-mono-9-octadecenoic acid dehydrated sorbitan ester, hexadecyltrimethylammonium chloride and water are in a weight ratio of 1:0.025:0.025:30; the resulting modified titanium silicate molecular sieve is designated as TS-S-5', and its specific surface area is 1433 m². 2 / g; Total pore volume is 0.55cm³ 3 / g; micropore volume is 0.27cm³ 3 / g; mesopore volume is 0.32cm³ 3 / g; the amount of acid with an acid strength H0 ≤ +3.85 characterized by Hammett indicator titration is 0.085 n-butylamine / g molecular sieve; the amount of acid with an acid strength H0 ≤ +4.8 is 0.86 n-butylamine / g molecular sieve, and the vanadium-titanium molar ratio is 0.1:1.

[0062] Preparation Example 8 Following the method of Preparation Example 2, the difference is that in step (2), the weight ratio of TS-S-2, octadecyltrimethylammonium chloride, and water is 1:0.003:30, and the resulting molecular sieve is designated as TS-S-6' with a specific surface area of ​​732 m². 2 / g; Total pore volume is 0.23cm³ 3 / g; micropore volume is 0.11cm³ 3 / g; mesopore volume is 0.13cm³ 3 / g; the amount of acid with an acid strength H0 ≤ +3.85 characterized by Hammett indicator titration is 0.034 n-butylamine / g molecular sieve; the amount of acid with an acid strength H0 ≤ +4.8 is 0.48 n-butylamine / g molecular sieve, and the vanadium-titanium molar ratio is 0.1:1.

[0063] Preparation Example 9 Following the method of Preparation Example 3, except that acetylacetone vanadium oxide was not added in step (2), the resulting molecular sieve was designated TS-S-7', with a specific surface area of ​​893 m². 2 / g; Total pore volume is 0.26cm³. 3 / g; micropore volume is 0.17cm³ 3 / g; mesopore volume is 0.14cm³ 3 / g; the amount of acid with an acid strength H0 ≤ +3.85 characterized by Hammett indicator titration is 0.041 n-butylamine / g molecular sieve; the amount of acid with an acid strength H0 ≤ +4.8 is 0.56 n-butylamine / g molecular sieve.

[0064] Example 1 TS-S-1' was used as the catalyst, and an aqueous solution of hydrogen peroxide (concentration of 30 wt%) was used as the oxidant. The molar ratio of ethylene to hydrogen peroxide was 1.2:1. After the reaction, the catalyst was filtered through a metal-ceramic composite membrane (the average pore size of the precision membrane was 50 nm, and the preparation method of the metal-ceramic composite membrane was referred to the preparation method in Example 1 of patent CN110252156B). The reaction was continuously cyclic for 1800 hours, the transmembrane pressure difference was <0.05 MPa, the catalyst mass concentration in the system remained unchanged, and the catalyst concentration detected in the product liquid was <10 ppm.

[0065] The reaction results are shown in Table 1.

[0066] Example 2 TS-S-2' was used as the catalyst, and an aqueous solution of hydrogen peroxide (concentration of 30 wt%) was used as the oxidant. The molar ratio of ethylene to hydrogen peroxide was 1.2:1. After the reaction, the catalyst was filtered through a metal-ceramic composite membrane (the average pore size of the precision membrane was 10 nm, and the preparation method of the metal-ceramic composite membrane was described in Example 2 of patent CN110252156B). The reaction was continuously cyclic for 2000 hours, the transmembrane pressure difference was <0.05 MPa, the catalyst mass concentration in the system remained constant, and the catalyst concentration detected in the product solution was <10 ppm.

[0067] The reaction results are shown in Table 1.

[0068] Example 3 TS-S-3' was used as the catalyst, and an aqueous hydrogen peroxide solution (concentration of 30 wt%) was used as the oxidant. The molar ratio of ethylene to hydrogen peroxide was 1.2:1. After the reaction, the catalyst was filtered through a metal-ceramic composite membrane (the average pore size of the precision membrane layer was 50 nm, and the preparation method of the metal-ceramic composite membrane was described in Example 3 of patent CN110252156B). The reaction was continuously cyclic for 1500 hours, the transmembrane pressure difference was <0.05 MPa, the catalyst mass concentration in the system remained unchanged, and the catalyst concentration detected in the product solution was <10 ppm.

[0069] The reaction results are shown in Table 1.

[0070] Example 4 The method of Example 1 was followed, except that TS-1' was used as the catalyst, and the reaction results are shown in Table 1.

[0071] Example 5 Following the method of Example 2, except that TS-2' was used as the catalyst, the reaction results are shown in Table 1.

[0072] Example 6 The method of Example 3 was followed, except that TS-S-4' was used as the catalyst. The results are shown in Table 1.

[0073] Example 7 The method of Example 1 was followed, except that TS-S-5' was used as the catalyst. The results are shown in Table 1.

[0074] Example 8 The method of Example 3 was followed, except that TS-S-6' was used as the catalyst. The results are shown in Table 1.

[0075] Example 9 The method is the same as in Example 3, except that TS-1 is used as the catalyst.

[0076] Example 10 The method of Example 3 was followed, except that TS-S-7' was used as the catalyst. The results are shown in Table 1.

[0077] Comparative Example 1 The method was followed in Example 1, except that a metal membrane (316L material, separation precision 0.1 mm) was used for filtration. After the catalyst was filtered through the metal membrane and continuously circulated for 200 hours, a transmembrane pressure difference >0.4 MPa appeared, the catalyst mass concentration in the system decreased by >10%, and the catalyst concentration detected in the product liquid was >0.15%.

[0078] Comparative Example 2 The method was followed in Example 1, except that a ceramic membrane (made of ZrO2, with a separation precision of 50 nm) was used for filtration. After the catalyst was filtered through the ceramic membrane and continuously circulated for 200 hours, a transmembrane pressure difference >0.9 MPa appeared, the catalyst mass concentration in the system decreased by >13%, and the catalyst concentration in the product solution was detected to be >0.18%. Detection revealed that the membrane core was damaged, leading to catalyst leakage.

[0079] Table 1

[0080] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for the direct production of ethylene glycol from ethylene using a metal-ceramic composite membrane separation, characterized in that, The method includes: reacting ethylene with hydrogen peroxide in the presence of an oxidative hydration bifunctional catalyst to obtain a material containing ethylene glycol, and collecting the product after separation by a metal-ceramic composite membrane.

2. The method according to claim 1, wherein, The metal-ceramic composite membrane sequentially comprises a base layer, a transition layer, and a precision membrane layer. The base layer is made of a metal material, the transition layer is made of a ceramic material and / or a metal material, and the precision membrane layer is made of a ceramic material. The material to be separated comes into contact with the precision membrane layer for separation. Preferably, the average pore size of the precision film is 5-100 nm.

3. The method according to claim 1 or 2, wherein, The conditions for the contact reaction include: The molar ratio of ethylene to hydrogen peroxide is 1-2:1; and / or The catalyst mass concentration is 5-30%; and / or Temperature is 20-90℃; and / or The pressure is 0.1-3 MPa.

4. The method according to any one of claims 1-3, wherein, The oxidation-hydration bifunctional catalyst is a modified MFI structure titanium-silicon molecular sieve, and the specific surface area of ​​the molecular sieve is ≥350 m². 2 / g, total pore volume ≥0.2cm³ 3 / g, micropore volume ≥0.12cm³ 3 / g, mesopore volume ≥0.15cm³ 3 / g, the amount of acid with an acid strength H0≤+3.85 is above 0.05 n-butylamine / g molecular sieve, and the amount of acid with an acid strength H0≤+4.8 is above 0.60 n-butylamine / g molecular sieve; the vanadium-titanium molar ratio of the molecular sieve is 0.01-0.4:1 in terms of elements.

5. The method according to claim 4, wherein, The titanium-silicon molar ratio of the molecular sieve, calculated as oxides, is 0.01-0.1:1; preferably 0.03-0.08:1; and / or The vanadium-titanium molar ratio of the molecular sieve is 0.03-0.1:1 (elementally); and / or The specific surface area is 950-1500 cm². 3 / g; and / or The total pore volume is 0.3-0.7 cm³. 3 / g; and / or The micropore volume is 0.15-0.28 cm³. 3 / g; and / or The mesopore volume is 0.2-0.6 cm³. 3 / g; and / or The acid strength H0 ≤ +3.85 has an acid content of 0.07-0.1 n-butylamine / g molecular sieve; and / or The acid strength H0≤+4.8 has an acid content of 0.7-0.9 n-butylamine / g molecular sieve.

6. The method according to any one of claims 1-5, wherein, The preparation method of the oxidative hydration bifunctional catalyst includes: mixing MFI structured titanium-silicon molecular sieve, surfactant, organic vanadium ester and water, performing solid-liquid separation, drying and calcination to obtain modified MFI structured titanium-silicon molecular sieve. The surfactant is selected from one or more of cationic surfactants, anionic surfactants, and nonionic surfactants. By weight, the ratio of the surfactant to the titanium-silicon molecular sieve is not less than 0.005; The ratio of organic vanadium ester to MFI structured titanium silicate molecular sieve, based on the molar amount of vanadium and titanium, is 0.01-0.4:

1.

7. The method according to claim 6, wherein, Based on oxides, the molar ratio of titanium to silicon in the MFI-structured titanium-silicon molecular sieve is 0.01-0.1:1, preferably 0.03-0.08:1; and / or The organovanadium ester is selected from one or more of vanadium acetylacetonate, vanadium oxalate, and vanadium acetylacetonate, preferably vanadium oxalate; and / or The anionic surfactant is selected from one or more of alkylbenzene sulfonates, alkyl sulfonate salts, and alkyl sulfonates, preferably one or more of sodium dodecylbenzene sulfonate, sodium α-alkenyl sulfonate, and sodium secondary alkyl sulfonate; and / or The cationic surfactant is selected from one or more of hexadecyltrimethylammonium chloride and octadecyltrimethylammonium chloride; and / or The nonionic surfactant is selected from one or more of fatty alcohol polyoxyethylene ether, alkylolamide, polyol monofatty acid ester, alkyl amine oxide, and N-alkylpyrrolidone, preferably one or more of sorbitan stearate, dehydrated sorbitan monooleate polyoxyethylene ether, polysorbate fatty acid ester-60, and (Z)-mono-9-octadecenoic acid dehydrated sorbitan ester. Preferably, the surfactant is a mixture of cationic and nonionic surfactants, and the content of each of the cationic and nonionic surfactants is not less than 25% and preferably not less than 40% based on the total weight of the surfactants. More preferably, the surfactant is a mixture of hexadecyltrimethylammonium chloride and (Z)-mono-9-octadecenoic acid sorbitol ester, wherein the content of each of the hexadecyltrimethylammonium chloride and (Z)-mono-9-octadecenoic acid sorbitol ester is not less than 40% by weight of the total surfactant.

8. The method according to claim 6 or 7, wherein, The surfactant to the titanium-silicon molecular sieve, by weight, has a ratio of 0.005-0.1:1, preferably 0.01-0.1:1; and / or The weight ratio of water to titanium-silicon molecular sieve is 2-50:1, preferably 10-30:1; and / or The ratio of organic vanadium ester to MFI structured titanium silicate molecular sieve is 0.03-0.1:1, based on the molar amount of vanadium and titanium.

9. The method according to any one of claims 6-8, wherein, The conditions for mixing include: The mixing temperature is 130-260℃, preferably 170-230℃; and / or The mixing time is 1-72 hours, preferably 5-48 hours.

10. The method according to any one of claims 6-9, wherein, The MFI structured titanium-silicon molecules are selected from one or more of TS-1, TS-2 and TS-S, with TS-S being preferred. The preparation methods of TS-S include: A silicon source, a titanium source, a template agent, a surfactant, and water are mixed, heated for reaction, followed by solid-liquid separation, drying, and calcination. The heating reaction includes a first-stage reaction, a second-stage reaction, and a third-stage reaction, and the conditions for the heating reaction include: The first-stage reaction temperature is 20-50℃; and / or The first-stage reaction time is 0.5-3.5 hours; and / or The second-stage reaction temperature is 70-100℃; and / or The second-stage reaction time is 0.5-3.5 hours; and / or The three-stage reaction temperature is 130-190℃; and / or The three-stage reaction time is 10-80 hours; Preferably, The silicon source is selected from organosilicates, preferably one or more of methyl silicate, ethyl silicate, propyl silicate, and butyl silicate; and / or The titanium source is selected from organic titanate esters, preferably one or more of methyl titanate, ethyl titanate, propyl titanate, and butyl titanate; and / or The template agent is selected from one or more of tetramethylammonium hydroxide, tetramethylammonium bromide, tetraethylammonium hydroxide, tetraethylammonium bromide, tetrapropylammonium hydroxide, tetrapropylammonium bromide, tetrabutylammonium hydroxide, and tetrabutylammonium bromide; and / or The surfactant is selected from one or more of cationic surfactants, anionic surfactants, and nonionic surfactants; Preferably, The anionic surfactant is selected from one or more of alkylbenzene sulfonates, alkyl sulfonate salts, and alkyl sulfonates, preferably one or more of sodium dodecylbenzene sulfonate, sodium α-alkenyl sulfonate, and sodium secondary alkyl sulfonate; and / or The cationic surfactant is selected from one or more of hexadecyltrimethylammonium chloride and octadecyltrimethylammonium chloride; and / or The nonionic surfactant is selected from one or more of fatty alcohol polyoxyethylene ether, alkylolamide, polyol monofatty acid ester, alkyl amine oxide, and N-alkylpyrrolidone, preferably one or more of sorbitan stearate, dehydrated sorbitan monooleate polyoxyethylene ether, polysorbate fatty acid ester-60, and (Z)-mono-9-octadecenoic acid dehydrated sorbitan ester. Preferably, the molar ratio of silicon source (based on oxide), titanium source (based on oxide), template agent, surfactant and water is 1:(0.01-0.1):(0.03-0.2):(0.0001-0.002):(5-80), more preferably 1:(0.03-0.008):(0.08-0.15):(0.0005-0.001):(10-40).

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