Catalyst for preparing vinyl alkyl ether through ethylene glycol dialkyl ether cracking reaction

Abstract

The invention discloses a catalyst for preparing vinyl alkyl ether by cracking reaction of ethylene glycol dialkyl ether, which is composed of an alkaline earth metal composite oxide main catalyst, a modifier and a carrier, the structural formula of the catalyst is x (M1.00XaYbOc)-yG / zZ, in the formula, M1.00XaYbOc is the main catalyst, M is alkaline earth metal element, X is at least one of alkali metal or rare earth element, and Y is at least one of B, Al, Ga, In, Si, Ge, Sn, Mn, Fe, Co, Ni, Cu or Zn element; g is a solid simple substance, nitride, carbide or sulfide modifier, and Z is a porous carrier with a high specific surface area; a, b and c are atomic ratios of elements X, Y and O respectively, and x, y and z are mass fractions of the main catalyst, the modifier and the carrier respectively. The catalyst is prepared by a mixing method, is simple in process, low in manufacturing cost and good in repeatability, and has high activity, selectivity and reaction stability when being used for preparing vinyl alkyl ether by removing alkanol from ethylene glycol dialkyl ether.

Description

Technical Field

[0001] This invention belongs to the field of chemical catalyst technology, specifically, it relates to a catalyst for the preparation of vinyl alkyl ethers from the cracking reaction of ethylene glycol dialkyl ethers. Background Technology

[0002] With the rapid development of my country's coal chemical industry, the production capacity of coal-based ethylene glycol has exceeded 10 million tons / year, and the total production capacity of petroleum-based and coal-based ethylene glycol has reached 30 million tons / year. Ethylene glycol production capacity is severely oversupplied, resulting in poor economic efficiency. Developing new downstream products to stimulate ethylene glycol consumption has become a key means to break this deadlock. Using inexpensive and readily available ethylene glycol as a starting material, the green solvent and chemical intermediate ethylene glycol mono / dialkyl ethers can be synthesized through etherification with alkane alcohols. Furthermore, the important organic chemical raw material and polymer monomer vinyl alkyl ethers can be prepared through the cracking of ethylene glycol mono / dialkyl ethers. This approach can not only stimulate ethylene glycol consumption and solve the overcapacity problem, but also promote technological progress and development in the vinyl ether industry. It can also address the safety and environmental risks associated with traditional acetylene and acetal processes for producing vinyl ethers (acetylene, the raw material in the acetylene process, and acetal, the intermediate in the acetal process, are prone to forming peroxides, posing an explosion risk; the liquid strong alkali used in the acetylene process causes equipment corrosion and environmental pollution).

[0003] Patents US5650544A, US6090988A, and JP3685942B disclose a Cs2O / SiO2 catalyst for the gas-phase dehydration of ethylene glycol monoethyl ether to prepare vinyl ethyl ether, at a reaction temperature of 420℃ and GHSV = 1500 h⁻¹. -1 At this temperature, the conversion rate of ethylene glycol monoethyl ether is 72.5%, and the selectivity of vinyl ethyl ether is 84.4%. However, the Cs₂O / SiO₂ catalyst is expensive, and Cs species are gradually lost with prolonged reaction time, leading to rapid catalyst deactivation and poor reaction stability. Patent CN111807937B discloses a method for synthesizing vinyl methyl ether from ethylene glycol dimethyl ether, using solid base catalysts such as magnesium oxide, cerium dioxide, calcium oxide, or a calcium-magnesium mixed oxide (calcium-magnesium molar ratio 0.1~4), at a temperature of 375~425℃, atmospheric pressure, and a space velocity of 1.0~10h⁻¹. -1The reaction is carried out under certain conditions. Because a single alkaline earth or rare earth oxide catalyst is used, the specific surface area is small, the utilization rate of the basic active centers is low, and it is easily deactivated, resulting in a short catalyst lifespan. Patent CN115772069A provides a method for synthesizing vinyl methyl ether, using alkali metal sodium or potassium, dibenzofuran, and ethylene glycol dimethyl ether as reactants in a molar ratio of 1:0.5~1:0.5~10. The alkali metal is added in a solid or molten state, and the reaction is carried out at a temperature of 60~150℃ and a pressure of 0.05~0.30MPa for 1.5~4.0 h to obtain vinyl methyl ether. Because the catalyst is an alkali metal and is used in extremely large quantities, there are serious safety hazards and continuous operation is not possible. On the one hand, the alkali metal is added in a solid or molten state, which makes it difficult to disperse or dissolve quickly into the reaction system, resulting in uneven catalyst distribution and easy to cause local violent reactions and large amounts of heat release. On the other hand, the purity requirements for raw materials and solvents are extremely high, and substances containing active hydrogen such as water or alcohol are not allowed to remain. Even so, the methanol produced in the reaction will still react with the alkali metal to form alkoxides and release hydrogen gas, posing a major safety risk and causing environmental pollution.

[0004] Therefore, there is an urgent need to develop a safer, more efficient, economical, or environmentally friendly catalyst for the cracking reaction of ethylene glycol dialkyl ethers to prepare vinyl alkyl ethers. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a catalyst for the pyrolysis reaction of ethylene glycol dialkyl ethers to prepare vinyl alkyl ethers. This catalyst is simple to prepare and relatively inexpensive, aiming to achieve safe, efficient, economical, environmentally friendly, and highly selective preparation of vinyl alkyl ethers.

[0006] In one aspect, the present invention provides a catalyst for the pyrolysis reaction of ethylene glycol dialkyl ethers to prepare vinylalkyl ethers, said catalyst being x(M) 1.00 X a Y b O c )-yG / zZ; where M 1.00 X a Y b O cThe catalyst is composed of M (selected from at least one element of alkaline earth metals), X (selected from at least one element of alkali metals or rare earth metals), Y (selected from at least one element of Group IIIA, Group IVA, or fourth-period transition metals), O (oxygen), G (modifying agent selected from at least one substance selected from graphite, boron powder, silicon powder, germanium powder, nitrides, carbides, and sulfides), and Z (porous support containing at least one substance selected from SiO2, Al2O3, TiO2, ZrO2, hydrotalcite, spinel, all-silica molecular sieve, or metal ion exchange molecular sieve). In the catalyst, 1.0, a, b, and c represent the molar ratios of M, X, Y, and O elements in the main catalyst, with a = 0~0.2 and b = 0~0.2. x, y, and z represent the relative mass fractions of the main catalyst, modifying agent, and support in the catalyst, with x = 20~98%, y = 2~30%, and z = 0~78%.

[0007] The nitride is selected from at least one of BN, AlN, GaN, C3N4, Si3N4, MoN, and W2N; the carbide is selected from at least one of B4C, SiC, ZrC, Fe3C, Co2C, MoC2, and WC; and the sulfide is selected from at least one of MoS2 or WS2.

[0008] Preferably, c is a value that satisfies the valence requirements of M, X, and Y.

[0009] Preferably, M is selected from at least one of Mg, Ca, Sr and Ba; X is selected from at least one of Li, Na, K, Rb, Cs, Sc, Y, La, Ce, Nd, Sm, Yb and Th; Y is selected from at least one of Al, Ga, In, Ge, Sn, Fe, Cu and Zn; G is selected from at least one of graphite, silicon powder, BN, AlN, C3N4, Si3N4, SiC, Fe3C, Co2C, MoS2 and WS2; and Z is selected from at least one of silica sol, silica gel, θ-Al2O3, mesoporous Al2O3, hydrotalcite, all-silica molecular sieve, titanium-silica molecular sieve and metal ion exchange molecular sieve.

[0010] a = 0~0.10, b = 0~0.10; x = 30~96%, y = 3~25% and z = 0~67%; the hydrotalcite is selected from Mg-Al hydrotalcite, Zn-Al hydrotalcite and Ni-Al hydrotalcite; the all-silicon molecules are screened from S-1, S-2, MCM-41, MCM-48 and SBA-15; the titanium-silicon molecules are screened from Tiβ, TS-1, TS-2 and TiMWW; the metal ion exchange molecules are screened from alkali metal, alkaline earth or rare earth metal ion exchange molecules MOR, β, ZSM-5, ZSM-11, ZSM-22, ZSM-23, MCM-22, MCM-49 and MCM-56.

[0011] In one or more embodiments, the alkyl group of the ethylene glycol dialkyl ether is a C1-C6 alkyl group or a C1-C6 alkyl group. 12 Substituted alkyl groups.

[0012] Preferably, the substituted alkyl group is a halogen-substituted alkyl group. Preferably, the substituted alkyl group is a chloroalkyl group or a fluoroalkyl group.

[0013] More preferably, the alkyl group of the ethylene glycol dialkyl ether is methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, cyclohexyl, 2-chloroethyl, perfluoromethyl, trifluoroethyl, pentafluoropropyl, heptafluorobutyl, perfluorohexylpropyl, or perfluorooctylpropyl.

[0014] In one or more embodiments, M is selected from at least one of Mg and Ca; X is selected from at least one of Li, K, La, Ce, Nd, and Sm; Y is selected from at least one of In, Si, Ge, and Zn; G is selected from at least one of graphite, silicon powder, C3N4, Si3N4, and SiC; Z is selected from at least one of silica gel, mesoporous Al2O3, Mg-Al hydrotalcite, S-1, SBA-15, TS-1, Li-ZSM-5, Mg-ZSM-5, Ca-MCM-22, and La-MCM-22; x = 50~95%, y = 4~20%, z = 0~46%;

[0015] a = 0, b = 0, or a = 0.01~0.10, b = 0, or a = 0, b = 0.01~0.10, or a = 0.01~0.05, b = 0.01~0.05.

[0016] In another aspect, the present invention provides a method for preparing a catalyst as described in any embodiment herein, where a = 0, b = 0, z = 0, the method comprising the following steps:

[0017] The hydroxide or oxide powder of M is mixed uniformly with a modifier, pore-forming agent, and binder with a particle size of less than 200 nm according to a stoichiometric ratio. The mixture is then granulated by spray drying, extrusion, or sheet forming. The granules are then calcined in flowing air at 300–400 °C for 1.0–2.0 h and at 500–600 °C for 3.0–5.0 h to obtain the catalyst x(M). 1.00 X a Y b O c )-yG / zZ particles.

[0018] Preferably, the oxide powder of M is obtained by calcining one or more of CaO, Ca(OH)2, MgO, Mg(OH)2, BaO, Ba(OH)2, SrO and Sr(OH)2 in flowing air at 500~600°C for 3.0~5.0h.

[0019] In another aspect, the present invention provides a method for preparing a catalyst as described in any embodiment herein, where a > 0, b > 0, z = 0, the method comprising the following steps:

[0020] S1: The hydroxide of M, the alkali metal hydroxide, the rare earth metal nitrate, and the precursor compound of Y are mixed in a stoichiometric ratio, and water is added and stirred for 0.5-2.0 h to form a slurry. The temperature of the slurry is maintained at 35-60℃ during stirring. After the slurry is evaporated to dryness, it is placed in flowing air and calcined at 300-400℃ for 1.0-2.0 h, 500-600℃ for 2.0-3.0 h, and 700-800℃ for 3.0-5.0 h to obtain alkaline earth metal composite oxide powder. The precursor compound of Y is selected from at least one substance selected from the group IIIA metal nitrate, group IVA metal acetate, and period IV transition metal nitrate.

[0021] S2: The alkaline earth metal composite oxide powder obtained in step S1 is mixed with a modifier, pore-forming agent, and binder with a particle size of less than 200 nm according to the stoichiometric ratio. The mixture is then formed into granules by spray drying, extrusion molding, or sheet forming. These granules are then calcined in flowing air at 300-400℃ for 1.0-2.0 h and 500-600℃ for 3.0-5.0 h to obtain the catalyst x(M). 1.00 X a Y b O c )-yG / zZ particles.

[0022] In another aspect, the present invention provides a method for preparing a catalyst as described in any embodiment herein, where a = 0, b = 0, z > 0, the method comprising the following steps:

[0023] S1: Mix the hydroxide of M with the powder of Z according to the stoichiometric ratio, add water and stir for 0.5~2.0h to make a slurry, and keep the temperature of the slurry at 35~60℃ during stirring; after evaporating the slurry to dryness, place it in flowing air and calcine at 300~400℃ for 1.0~2.0h and 500~600℃ for 3.0~5.0h to obtain alkaline earth metal oxide powder containing the carrier;

[0024] S2: The alkaline earth metal oxide powder containing the support obtained in step S1 is mixed with a modifier, pore-forming agent, and binder with a particle size of less than 200 nm according to the stoichiometric ratio. The mixture is then formed into particles by spray drying, extrusion molding, or sheet forming. These particles are then calcined in flowing air at 300-400℃ for 1.0-2.0 h and 500-600℃ for 3.0-5.0 h to obtain the catalyst x(M). 1.00 X a Y b O c )-yG / zZ particles.

[0025] In another aspect, the present invention provides a method for preparing a catalyst as described in any embodiment herein, where a > 0, b > 0, z > 0, the method comprising the following steps:

[0026] S1: The hydroxide of M, the alkali metal hydroxide, the rare earth metal nitrate, the precursor compound of Y, and the powder of Z are mixed according to the stoichiometric ratio. Water is added and the mixture is stirred for 0.5-2.0 h to form a slurry. The temperature of the slurry is maintained at 35-60℃ during stirring. After the slurry is evaporated to dryness, it is placed in flowing air and calcined at 300-400℃ for 1.0-2.0 h, 500-600℃ for 2.0-3.0 h, and 700-800℃ for 3.0-5.0 h to obtain an alkaline earth metal composite oxide powder containing a carrier. The precursor compound of Y is selected from at least one substance selected from the group IIIA metal nitrate, group IVA metal acetate, and period IV transition metal nitrate.

[0027] S2: The alkaline earth metal composite oxide powder containing the carrier obtained in step S1 is mixed uniformly with a modifier, pore-forming agent, and binder with a particle size of less than 200 nm according to the stoichiometric ratio. The mixture is then formed into granules by spray drying, extrusion molding, or sheet forming. These granules are then calcined in flowing air at 300-400℃ for 1.0-2.0 h and 500-600℃ for 3.0-5.0 h to obtain the catalyst x(M). 1.00 X a Y b O c )-yG / zZ particles.

[0028] Preferably, the pore-forming agent is at least one of water, nitric acid, acetic acid, citric acid, sorbic acid, ethylene glycol, glycerol, and vegetable oil, and is added in an amount of 2-8 wt% of the hydroxide or oxide powder in step S2. Preferably, the binder is at least one of guar gum powder, methylcellulose, polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and starch, and is added in an amount of 3-15 wt% of the hydroxide or oxide powder in step S2.

[0029] More preferably, the pore-forming agent is at least one of water, nitric acid, citric acid, and glycerol, and the amount added is 3-5 wt% of the hydroxide or oxide powder in step S2. More preferably, the binder is at least one of guar gum powder, methylcellulose, PEG 200-2000, and starch, and the amount added is 5-10 wt% of the hydroxide or oxide powder in step S2.

[0030] In one or more embodiments, the catalyst is a particulate catalyst, wherein the catalyst x(M) 1.00 X a Y b O c The particles of )-yG / zZ are microspheres with a diameter of 30~300μm, cylindrical particles with a diameter of 2~5mm and a length of 3~8mm, or clover-shaped particles with a diameter of 2~5mm and a length of 3~8mm.

[0031] Preferably, the catalyst x(M) 1.00 X a Y b O c The particles of )-yG / zZ are microspheres with a particle size of 50~300μm, cylinders with a diameter of 2~4mm and a length of 3~5mm, or clover-shaped particles with a diameter of 2~4mm and a length of 3~5mm. More preferably, the catalyst x(M 1.00 X a Y b O c The particles of )-yG / zZ are microspheres with a diameter of 100~200μm or clover-shaped particles with a diameter of 2~3mm and a length of 3~4mm.

[0032] In another aspect, the present invention provides the application of the catalyst as described in any embodiment herein in the catalytic cracking reaction of ethylene glycol dialkyl ethers to prepare vinyl alkyl ethers, characterized in that the reactor feed for the reaction includes a dilution gas; and the reaction conditions are a temperature of 350–480 °C, a pressure of 0.01–1.00 MPa, and a liquid hourly space velocity (WHSV) of 0.1–5.0 h⁻¹ for the ethylene glycol dialkyl ether feed. -1 Volumetric hourly space velocity (VHSV) of feed gas and dilution gas is 0~5000 h⁻¹ -1 .

[0033] Preferably, the reaction conditions are: temperature 400~440℃, pressure 0.10~0.50MPa, and ethylene glycol dialkyl ether feed liquid weight hourly space velocity (WHSV) 0.3~1.5h. -1 Volumetric hourly space velocity (VHSV) of feed gas is 0–2000 h⁻¹ -1 .

[0034] Preferably, the reaction process involves preheating ethylene glycol dialkyl ether or a mixture thereof with a diluent gas to the reaction temperature, and then feeding it into a reactor filled with the catalyst for reaction.

[0035] More preferably, the reactor is a fixed-bed reactor or a fluidized-bed reactor. Even more preferably, the reactor is an isothermal fixed-bed reactor, an adiabatic fixed-bed reactor, a fixed fluidized-bed reactor, or a circulating fluidized-bed reactor. Even more preferably, the reactor is an adiabatic fixed-bed reactor.

[0036] Preferably, the diluting gas is selected from at least one of N2, H2O, CO2, CH4, H2, N2-H2O, N2-CO2, N2-CH4, N2-H2, H2O-CO2, H2O-CH4, H2O-H2, CO2-CH4, CO2-H2, CH4-H2, N2-H2O-CO2, N2-H2O-CH4, N2-H2O-H2, H2O-CO2-CH4, H2O-CO2-H2, CO2-CH4-H2, N2-H2O-CO2-CH4, N2-H2O-CO2-H2, N2-CO2-CH4-H2, H2O-CO2-CH4-H2, N2-H2O-CO2-CH4-H2, oxygen-deficient air, oxygen-containing N2 gas, oxygen-containing CO2, and industrial exhaust gas.

[0037] More preferably, the O2 content in the oxygen-deficient air is ≤2 vol%. Preferably, the O2 content in the oxygen-containing N2 is ≤2 vol%. Preferably, the organic matter content in the industrial exhaust gas is ≤200 ppm, and the O2 content is ≤2 vol%.

[0038] More preferably, the diluting gas is selected from at least one of N2, N2-H2O, oxygen-deficient air, oxygen-containing N2, and industrial exhaust gas.

[0039] In another aspect, the present invention provides a method for preparing vinyl alkyl ethers, the method comprising catalyzing the cracking reaction of ethylene glycol dialkyl ethers using a catalyst as described in any embodiment herein.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. This invention provides an alkaline earth-based ethylene glycol dialkyl ether dealkanolation catalyst that is easy to operate, low in cost, and easy to repeat, and its preparation method: a catalyst containing alkaline earth metal oxides and modifying agents, a catalyst containing alkaline earth metal oxides, modifying agents and supports, and a catalyst containing alkaline earth and other metal oxides, modifying agents and supports are prepared by a mixing method. The preparation process is simple, convenient to operate, has good repeatability, the raw materials are inexpensive and readily available, and the manufacturing cost is low.

[0042] 2. This invention provides an alkaline earth oxide or composite oxide catalyst with excellent dealkanization performance of ethylene glycol dialkyl ethers: by adding structural aids X (alkali metal or rare earth metal oxides) and Y (Group IIIA, IVA, or third-period transition metal oxides), a dual-functional aid for electronic and thermal conductivity G, and a high specific surface area porous support Z to improve dispersibility, the structural stability of the active component alkaline earth oxide, the ability of the basic center to activate ethylene glycol dialkyl ethers, the utilization rate of the active center, and the amount of raw material adsorbed are improved, thereby endowing x(M) with the following properties: 1.00 X a Y b O c The )-yG / zZ catalyst exhibits excellent dealkylation reaction performance.

[0043] 3. This invention provides a high-performance alkaline earth catalyst for the preparation of vinyl alkyl ethers from ethylene glycol dialkyl ethers via dealcanolation. When used in the dealcanolation reaction of ethylene glycol dialkyl ethers, the process conditions are relatively mild and the operation is highly safe. It has high dealcanolation reaction activity, selectivity and stability, overcoming the problems of easy deactivation and short life of existing ethylene glycol dialkyl ether dealcanolation catalysts. It also avoids the defects of existing technologies such as acetylene method and acetal method for producing vinyl ethers, such as safety hazards, environmental pollution and poor catalyst stability. Detailed Implementation

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Unless otherwise specified, all experimental materials used in the following examples are commercially available.

[0046] In the following embodiments, the catalyst activity evaluation and analysis method is as follows: the catalyst is filled into the isothermal section of a fixed-bed reaction tube, and the filling sequence is quartz sand-catalyst-quartz sand from top to bottom. The raw material is pumped to the preheater, heated and vaporized, and then fed into the reactor. The reaction products are analyzed online by gas chromatography with an FID detector and an RTx-624 capillary column. The conversion rate X of ethylene glycol dialkyl ether and the selectivity S of vinyl alkyl ether are calculated using the corrected area normalization method. The calculation formula is as follows:

[0047]

[0048]

[0049] Examples 1-6: Preparation of Alkali Earth Oxide Catalysts Containing Modified Additives

[0050] According to the stoichiometric ratios of the catalyst compositions listed in Table 1, Ca or Ca and Mg hydroxides were mixed with modified additives C3N4, Si or SiC powder with a particle size of less than 200 nm, 5.0% by weight of pore-forming agent citric acid and 8.0% by weight of binder methylcellulose, and then the mixture was shaped into clover-shaped particles with a diameter of 2.6 mm and a length of 3.0 mm. The particles were then calcined in flowing air at 350 °C for 2.0 h and 550 °C for 5.0 h to obtain alkaline earth oxide particle catalysts Cat-1 to Cat-6 containing modified additives.

[0051] Examples 7-12: Preparation of alkaline earth oxide catalysts containing oxide additives and modifying additives

[0052] S1: According to the stoichiometric ratio of the catalyst composition listed in Table 1, the hydroxides of Ca and Mg are mixed with at least one of LiOH, KOH, lanthanum nitrate, cerium nitrate, indium nitrate, germanium acetate or zinc nitrate, and water is added at 50°C and stirred for 1.0 h to prepare a slurry. After evaporation to dryness, the slurry is placed in flowing air and calcined at 350°C for 2.0 h, 550°C for 3.0 h and 750°C for 5.0 h to obtain an alkaline earth composite oxide powder containing oxide additives;

[0053] S2: According to the stoichiometric ratio of the catalyst composition listed in Table 1, the alkaline earth composite oxide powder containing oxide additives obtained in step S1 is mixed with modified additives C3N4, Si or SiC powder with a particle size of less than 200 nm, as well as 5.0% by weight of pore-forming agent citric acid and 8.0% by weight of binder methylcellulose. The mixture is then formed into clover-shaped particles with a diameter of 2.6 mm and a length of 3.0 mm. The particles are then calcined in flowing air at 350 °C for 2.0 h and 550 °C for 5.0 h to obtain alkaline earth oxide particle catalysts Cat-7~Cat-12 containing modified additives and carriers.

[0054] Examples 13-18: Preparation of Alkaline Earth Oxide Catalysts Containing Modified Additives and Supports

[0055] S1: According to the stoichiometric ratio of the catalyst composition listed in Table 1, the hydroxides of Ca and Mg are mixed with the support powder selected from silica gel, SBA-15, TS-1, Mg-ZSM-5 and Ca-MCM-22, and water is added and stirred for 1.0 h at 50 °C to prepare a slurry. After evaporation to dryness, the slurry is placed in flowing air and calcined at 350 °C for 2.0 h and 550 °C for 5.0 h to obtain the alkaline earth oxide powder containing the support.

[0056] S2: According to the stoichiometric ratio of the catalyst composition listed in Table 1, the alkaline earth oxide powder with support obtained in step S1 is mixed with the modified auxiliary agent C3N4, Si or SiC powder with a particle size of less than 200nm, as well as 5.0% of the pore-forming agent citric acid and 8.0% of the binder methylcellulose by weight of the alkaline earth oxide powder. The mixture is then formed into clover-shaped particles with a diameter of 2.6mm and a length of 3.0mm. The particles are then calcined in flowing air at 350℃ for 2.0h and 550℃ for 5.0h to obtain alkaline earth oxide particle catalysts Cat-13~Cat-18 containing modified auxiliary agents and support.

[0057] Examples 19-24: Preparation of alkaline earth oxide catalysts containing oxide additives, modifying additives, and supports

[0058] S1: According to the stoichiometric ratio of the catalyst composition listed in Table 1, the hydroxides of Ca and Mg are mixed with at least one of LiOH, KOH, lanthanum nitrate, cerium nitrate, indium nitrate, germanium acetate or zinc nitrate, and a support powder selected from silica gel, SBA-15, TS-1, Li-ZSM-5, Mg-ZSM-5, Ca-MCM-22 and La-MCM-22. Water is added and stirred at 50°C for 1.0 h to make a slurry. After evaporation to dryness, the slurry is calcined in flowing air at 350°C for 2.0 h, 550°C for 3.0 h and 750°C for 5.0 h to obtain an alkaline earth composite oxide powder containing oxide additives and a support.

[0059] S2: According to the stoichiometric ratios of the catalyst compositions listed in Table 1, the alkaline earth composite oxide powder containing oxide additives and supports obtained in step S1 is mixed with modified additives C3N4, Si or SiC powder with a particle size of less than 200 nm, as well as 5.0% by weight of pore-forming agent citric acid and 8.0% by weight of binder methylcellulose. The mixture is then sheeted into clover-shaped particles with a diameter of 2.6 mm and a length of 3.0 mm. The particles are then calcined in flowing air at 350 °C for 2.0 h and 550 °C for 5.0 h to obtain alkaline earth composite oxide particle catalysts Cat-19~Cat-24 containing oxide additives, modified additives and supports.

[0060] Comparative Examples 1-2: Preparation of single alkaline earth oxide catalysts without additives and supports

[0061] According to the stoichiometric ratios of the catalyst compositions listed in Table 1, Ca or Ca and Mg hydroxides were mixed with 5.0% by weight of pore-forming agent citric acid and 8.0% by weight of binder methylcellulose. The mixture was then sheeted into clover-shaped particles with a diameter of 2.6 mm and a length of 3.0 mm. The particles were then calcined in flowing air at 350 °C for 2.0 h and 550 °C for 5.0 h to obtain single alkaline earth oxide particle catalysts Cat-01 and Cat-02.

[0062] Comparative Examples 3-4: Preparation of Alkali Earth Composite Oxide Catalysts Without Modifying Agents and Supports

[0063] S1: According to the stoichiometric ratio of the catalyst composition listed in Table 1, the hydroxides of Ca and Mg are mixed with lanthanum nitrate or lanthanum nitrate and zinc nitrate, and water is added and stirred for 1.0 h at 50 °C to make a slurry. After evaporation to dryness, the slurry is placed in flowing air and calcined at 350 °C for 2.0 h, 550 °C for 3.0 h and 750 °C for 5.0 h to obtain alkaline earth composite oxide powder containing oxide additives;

[0064] S2: According to the stoichiometric ratio of the catalyst composition listed in Table 1, the alkaline earth composite oxide powder obtained in step S1 is mixed with 5.0% by weight of pore-forming agent citric acid and 8.0% by weight of binder methylcellulose, and then shaped into clover-shaped particles with a diameter of 2.6 mm and a length of 3.0 mm. The particles are then calcined in flowing air at 350°C for 2.0 h and 550°C for 5.0 h to obtain alkaline earth composite oxide particle catalysts Cat-03 and Cat-04.

[0065] Table 1: Catalyst numbers and chemical compositions of Examples 1-24 and Comparative Examples 1-4

[0066]

[0067] Examples 25-36 and Comparative Examples 5-6: Preparation of vinyl methyl ether from ethylene glycol dimethyl ether via methanol removal

[0068] Ethylene glycol dimethyl ether and diluent gas N2 are fed into a preheater and heated to the reaction temperature. Then, the mixture is fed into a micro-fixed-bed reactor packed with small granular catalyst (crushed to 40-60 mesh). The reactor operates at a temperature of 400-440℃, a pressure of 0.1-0.4 MPa, and a weight hourly space velocity (WHSV) of 0.25-1.00 h⁻¹ for the ethylene glycol dimethyl ether feed liquid. -1 When feeding N2 gas, the volumetric hourly space velocity is 500~2000 h⁻¹. -1 Under the specified conditions, the methanol removal reaction of ethylene glycol dimethyl ether was carried out. The catalysts used in each example and the results after 10 hours of reaction are listed in Table 2.

[0069] Table 2: Reactions for the preparation of vinyl methyl ether from methanol by methanol removal from ethylene glycol dimethyl ether

[0070]

[0071] As shown in Tables 1 and 2, all catalysts with only the modifier, those with both the modifier and the oxide, those with both the modifier and the support, and those with both the modifier, the oxide, and the support all exhibit good catalytic performance in the demethanolization of ethylene glycol dimethyl ether to vinyl methyl ether, with a conversion rate of ethylene glycol dimethyl ether of 88.2%–96.7% and a selectivity of 95.8%–99.6%.

[0072] Comparing the catalyst composition and reaction results of Examples 25 and 5, and Examples 30 and 6 in Table 2, it can be found that under the same main catalyst and reaction conditions, Examples 25 and 30, using the modified Cat-1 and Cat-10 catalysts, achieved conversion rates of 88.2% and 94.5%, respectively, while Comparative Examples 5 and 6, using the unmodified Cat-01 and Cat-04 catalysts, achieved conversion rates of 81.5% and 86.2%, respectively. Clearly, the addition of modified additives can significantly improve the catalytic activity (conversion rate) of the catalyst, while the selectivity for the target product, vinyl methyl ether, remains almost unchanged. Among these, catalysts with the simultaneous addition of alkali metal oxide additives and / or supports (Cat-7, Cat-10, Cat-12, and Cat-21) exhibit relatively higher reactivity and target product selectivity.

[0073] Comparing the catalyst composition, reaction conditions, and results of the various embodiments in Tables 1 and 2, it can be seen that, based on the addition of modification, the addition of oxide promoters and / or supports also improves the catalytic activity to a certain extent, while the selectivity of the target product changes very little; increasing the reaction temperature, increasing the system pressure, and decreasing the feed space velocity significantly improve the feed conversion rate, while slightly reducing the selectivity of vinyl methyl ether.

[0074] Examples 37-48 and Comparative Examples 7-8: Preparation of vinyl ethyl ether from ethylene glycol diethyl ether via ethanol removal

[0075] Ethylene glycol diethyl ether and diluent gas N2 are fed into a preheater and heated to the reaction temperature. Then, the mixture is fed into a micro-fixed-bed reactor packed with small-particle catalyst (crushed to 40-60 mesh). The reactor operates at a temperature of 400-430℃, a pressure of 0.1-0.3 MPa, and a weight hourly space velocity (WHSV) of 0.25-1.00 h⁻¹ for the ethylene glycol diethyl ether feed liquid. -1 When feeding N2 gas, the volumetric hourly space velocity is 500~2000 h⁻¹. -1Under the specified conditions, the ethylene glycol diethyl ether deethanolination reaction was carried out. The catalysts used in each example and the results after 10 hours of reaction are listed in Table 3.

[0076] As can be seen from the catalysts, reaction conditions and results of each embodiment in Table 3, all catalysts with added modifiers have excellent cracking reaction activity, with ethylene glycol diethyl ether conversion and vinyl ethyl ether selectivity of 86.3~94.8% and 96.2~97.8%, respectively; among them, the catalysts with added oxide modifiers and / or supports have relatively higher reaction activity and target product selectivity.

[0077] Comparing Example 39 with Comparative Example 7 and Example 40 with Comparative Example 8 in Table 3, it can be found that, using the same reaction process conditions and the same main catalyst, the catalysts with added modifiers (Examples 39 and 40) have higher catalytic activity for the deethanolination of ethylene glycol diethyl ether compared to the catalysts without added modifiers (Comparative Examples 7 and 8). The conversion rates of Examples 39 and 40 using catalysts with added modifiers are 86.3% and 91.8%, respectively, while the conversion rates of Comparative Examples 7 and 8 using catalysts without added modifiers are 82.7% and 87.5%, respectively.

[0078] Table 3: Reactions for the preparation of vinyl ethyl ether from ethylene glycol diethyl ether via the deethanolification process

[0079]

[0080] Examples 49-54: Preparation of vinyl alkyl ethers from different ethylene glycol dialkyl ethers via dealkanization

[0081] Ethylene glycol dialkyl ether was fed into a preheater along with diluent gas N2 and heated to the reaction temperature. The mixture was then fed into a micro-fixed-bed reactor packed with Cat-24 small-particle catalyst. The reaction was carried out at a temperature of 400°C, a system pressure of 0.25 MPa, and a weight hourly space velocity (WHSV) of 0.5 h⁻¹ for the ethylene glycol dialkyl ether feed liquid. -1 When feeding N2 gas, the volumetric hourly space velocity is 1000 h⁻¹ -1 The ethylene glycol dialkyl ether dealkylation reaction was carried out, and the results after 10 hours of reaction are listed in Table 4.

[0082] Table 4 shows that the same catalyst Cat-24 (75wt% Ca) using the addition of metal oxide additives, modifiers, and supports... 0.5 Mg 0.5 Li 0.02 La 0.02 Ge 0.01 O 1.06(5wt% C3N4 / 20wt% SBA-15) Under the same reaction process conditions, both alkyl and substituted alkyl ethylene glycol diethers exhibit excellent reactivity and selectivity, with conversion rates and vinyl alkyl ether selectivities ranging from 87.9% to 92.8% and 98.0% to 99.3%, respectively. Furthermore, with increasing alkyl chain length, the dealkanolization activity of ethylene glycol dialkyl ethers decreases, resulting in a slight decrease in both conversion rate and vinyl alkyl ether selectivity.

[0083] Table 4: Reactions for the preparation of vinyl alkyl ethers from ethylene glycol dialkyl ethers using catalyst Cat-24

[0084]

[0085] Example 55: Stability of methanol removal reaction of ethylene glycol dimethyl ether

[0086] Ethylene glycol dimethyl ether was fed into a preheater along with diluent gas N2 and heated to the reaction temperature. Then, 5.0 kg of Cat-23 (70 wt% Ca) clover-shaped granular catalyst (2.6 mm in diameter and 3.0 mm in length) was introduced. 0.5 Mg 0.5 K 0.02 Ce 0.01 In 0.0 2O 1.06 In a fixed-bed single-tube reactor (50 mm inner diameter, 3500 mm height of isothermal section) containing -5 wt% C3N4 / 25 wt% SiO2, at a reaction temperature of 420 °C, a system pressure of 0.12 MPa, and a weight hourly space velocity (WHSV) of 0.50 h⁻¹ for the ethylene glycol dimethyl ether feed liquid. -1 When feeding N2 gas, the volumetric hourly space velocity is 1000 h⁻¹ -1 The reaction stability of ethylene glycol dimethyl ether to vinyl methyl ether via methanol removal was investigated.

[0087] After 10 h, 50 h, 100 h, and 200 h of operation, the single-pass conversion rates of ethylene glycol dimethyl ether (EDGDME) were 91.8%, 91.3%, 91.3%, and 91.1%, respectively, and the selectivities for vinyl methyl ether were 99.0%, 99.2%, 99.2%, and 99.3%, respectively. This indicates that the alkaline earth oxide catalyst, which simultaneously incorporates modified additives, oxide additives, and a support, exhibits good stability in the catalytic demethanolization reaction of EGDME.

[0088] Comparative Example 9: Stability of methanol removal reaction of ethylene glycol dimethyl ether

[0089] The catalyst shape and size, catalyst loading method, catalytic reaction operation process and conditions used in this comparative example are the same as those in Example 55, except that the catalyst used is a particulate catalyst Cat-02 (100wt% Ca). 0.5 Mg 0.5 O 1.0 ).

[0090] When the reaction was run for 10 h and 50 h, the conversion rates of ethylene glycol dimethyl ether were 86.6% and 57.8%, respectively, and the selectivity of vinyl methyl ether was 99.1% and 99.2%, respectively. It can be seen that after 50 h of reaction, the catalyst activity decreased significantly, and the conversion rate of ethylene glycol dimethyl ether decreased by about 33%, indicating that the methanol removal reaction of alkaline earth oxide catalyst without the addition of promoters and supports has poor stability.

[0091] Example 56: Stability of the deethanolization reaction of ethylene glycol diethyl ether

[0092] Ethylene glycol diethyl ether was fed into a preheater along with diluent gas N2 and heated to the reaction temperature. Then, 5.0 kg of Cat-24 (75 wt% Ca) clover-shaped granular catalyst (2.6 mm in diameter and 3.0 mm in length) was introduced. 0.5 Mg 0.5 Li 0.02 La 0.02 Ge 0.01 O 1.06 In a fixed-bed single-tube reactor (50 mm inner diameter, 3500 mm height of isothermal section) containing -5 wt% C3N4 / 20 wt% SBA-15, at a reaction temperature of 410 °C, a system pressure of 0.20 MPa, and a feed weight hourly space velocity of 0.50 h⁻¹ for ethylene glycol diethyl ether, the reaction was carried out at a reaction temperature of 410 °C, a system pressure of 0.20 MPa, and a feed weight hourly space velocity of 0.50 h⁻¹. -1 nitrogen volume hourly space velocity 1000 h⁻¹ -1 The reaction stability of the deethanolization of ethylene glycol diethyl ether to produce vinyl ethyl ether was investigated.

[0093] After 10 h, 50 h, 100 h, and 200 h of operation, the single-pass conversion rates of ethylene glycol diethyl ether were 87.8%, 87.5%, 87.3%, and 87.2%, respectively, and the selectivities of vinyl ethyl ether were 97.2%, 97.3%, 97.3%, and 97.4%, respectively. This indicates that the alkaline earth oxide catalyst, which simultaneously incorporates a modifying agent, an oxide auxiliary agent, and a support, exhibits good stability in the ethylene glycol diethyl ether catalytic deethanolization reaction.

[0094] Comparative Example 10: Stability of ethylene glycol diethyl ether in the deethanolination reaction

[0095] The catalyst shape and size, catalyst loading method, catalytic reaction operation process and conditions used in this comparative example are the same as those in Example 56, except that a particulate catalyst Cat-03 (100wt% Ca) is used. 0.5 Mg 0.5 La 0.04 O 1.06 ).

[0096] After 10 h and 50 h of reaction, the conversion rates of ethylene glycol diethyl ether were 84.6% and 48.5%, respectively, and the selectivity of vinyl ethyl ether was 97.5% and 97.3%, respectively. It is evident that after 50 h of reaction, the catalyst activity significantly decreased, and the conversion rate of ethylene glycol dimethyl ether decreased by approximately 43%. This indicates that the alkaline earth oxide catalyst without additives and a support exhibits poor stability in the deethanolination reaction.

[0097] In summary, the novel alkaline earth oxide catalyst provided by this invention exhibits excellent catalytic performance for the dealkanization of ethylene glycol dialkyl ethers to prepare vinyl alkyl ethers. By adding modifying agents, oxide agents, and / or porous support materials to the alkaline earth oxides, not only can the reaction activity be improved, but the reaction stability can also be greatly enhanced.

[0098] Special Note: The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A catalyst for the pyrolysis reaction of ethylene glycol dialkyl ethers to prepare vinylalkyl ethers, characterized in that, The catalyst is x (M 1.00 X a Y b O c )- y G / z Z; where M 1.00 X a Y b O c The catalyst is composed of M (selected from at least one element of alkaline earth metals), X (selected from at least one element of alkali metals or rare earth metals), Y (selected from at least one element of Group IIIA, Group IVA, or fourth-period transition metals), O (oxygen), G (modifying agent selected from at least one substance selected from graphite, boron powder, silicon powder, germanium powder, nitrides, carbides, and sulfides), and Z (porous support containing at least one substance selected from SiO2, Al2O3, TiO2, ZrO2, hydrotalcite, spinel, all-silica molecular sieves, or metal ion-exchange molecular sieves). 1.0 , a , b and c These represent the molar ratios of M, X, Y, and O elements in the main catalyst, respectively. a = 0~0.2、 b = 0~0.2; x, y and z These represent the relative mass fractions of the main catalyst, modifying agent, and support in the catalyst, respectively. x = 20~98% y = 2~30% and z = 0~78%; The nitride is selected from at least one of BN, AlN, GaN, C3N4, Si3N4, MoN, and W2N; the carbide is selected from at least one of B4C, SiC, ZrC, Fe3C, Co2C, MoC2, and WC; and the sulfide is selected from at least one of MoS2 or WS2.

2. The catalyst according to claim 1, characterized in that, The alkyl group of the ethylene glycol dialkyl ether is a C1-C6 alkyl group or a C1-C6 alkyl group. 12 Substituted alkyl groups.

3. The catalyst according to claim 1, characterized in that, M is selected from at least one of Mg and Ca; X is selected from at least one of Li, K, La, Ce, Nd and Sm; Y is selected from at least one of In, Si, Ge and Zn; G is selected from at least one of graphite, silica powder, C3N4, Si3N4 and SiC; Z is selected from at least one of silica gel, mesoporous Al2O3, Mg-Al hydrotalcite, S-1, SBA-15, TS-1, Li-ZSM-5, Mg-ZSM-5, Ca-MCM-22 and La-MCM-22. a = 0、 b = 0, or a = 0.01~0.10、 b = 0, or a = 0、 b =0.01~0.10, or a = 0.01~0.05、 b =0.01~0.05; x = 50~95%, y = 4~20% and z = 0~46%.

4. A method for preparing a catalyst according to any one of claims 1-3, characterized in that, a = 0, b =0, z = 0, the method includes the following steps: The hydroxide or oxide powder of M is mixed uniformly with a modifier, pore-forming agent, and binder with a particle size of less than 200 nm according to a stoichiometric ratio. The mixture is then formed into granules by spray drying, extrusion, or sheet forming. The granules are then calcined in flowing air at 300–400 °C for 1.0–2.0 h and at 500–600 °C for 3.0–5.0 h to obtain the catalyst. x (M 1.00 X a Y b O c )- y G / z Z particles.

5. A method for preparing a catalyst according to any one of claims 1-3, characterized in that, a >0, b >0, z = 0, the method includes the following steps: S1: The hydroxide of M, the alkali metal hydroxide, the rare earth metal nitrate, and the precursor compound of Y are mixed in a stoichiometric ratio, and water is added and stirred for 0.5-2.0 h to form a slurry. The temperature of the slurry is maintained at 35-60℃ during stirring. After the slurry is evaporated to dryness, it is placed in flowing air and calcined at 300-400℃ for 1.0-2.0 h, 500-600℃ for 2.0-3.0 h, and 700-800℃ for 3.0-5.0 h to obtain alkaline earth metal composite oxide powder. The precursor compound of Y is selected from at least one substance selected from the group IIIA metal nitrate, group IVA metal acetate, and period IV transition metal nitrate. S2: The alkaline earth metal composite oxide powder obtained in step S1 is mixed with a modifier, pore-forming agent, and binder with a particle size of less than 200 nm according to the stoichiometric ratio. The mixture is then formed into granules by spray drying, extrusion molding, or sheet forming. The granules are then calcined in flowing air at 300-400℃ for 1.0-2.0 h and 500-600℃ for 3.0-5.0 h to obtain the catalyst. x (M 1.00 X a Y b O c )- y G / z Z particles.

6. A method for preparing a catalyst according to any one of claims 1-3, characterized in that, a = 0, b =0, z >0, the method includes the following steps: S1: Mix the hydroxide of M with the powder of Z according to the stoichiometric ratio, add water and stir for 0.5~2.0h to make a slurry, and keep the temperature of the slurry at 35~60℃ during stirring; after evaporating the slurry to dryness, place it in flowing air and calcine at 300~400℃ for 1.0~2.0h and 500~600℃ for 3.0~5.0h to obtain alkaline earth metal oxide powder containing the carrier; S2: The alkaline earth metal oxide powder containing the support obtained in step S1 is mixed with a modifier, pore-forming agent, and binder with a particle size of less than 200 nm according to the stoichiometric ratio. The mixture is then formed into particles by spray drying, extrusion molding, or sheet forming. The particles are then calcined in flowing air at 300-400℃ for 1.0-2.0 h and 500-600℃ for 3.0-5.0 h to obtain the catalyst. x (M 1.00 X a Y b O c )- y G / z Z particles.

7. A method for preparing a catalyst according to any one of claims 1-3, characterized in that, a >0, b >0, z >0, the method includes the following steps: S1: The hydroxide of M, the alkali metal hydroxide, the rare earth metal nitrate, the precursor compound of Y, and the powder of Z are mixed according to the stoichiometric ratio. Water is added and the mixture is stirred for 0.5-2.0 h to form a slurry. The temperature of the slurry is maintained at 35-60℃ during stirring. After the slurry is evaporated to dryness, it is placed in flowing air and calcined at 300-400℃ for 1.0-2.0 h, 500-600℃ for 2.0-3.0 h, and 700-800℃ for 3.0-5.0 h to obtain an alkaline earth metal composite oxide powder containing a carrier. The precursor compound of Y is selected from at least one substance selected from the group IIIA metal nitrate, group IVA metal acetate, and period IV transition metal nitrate. S2: The alkaline earth metal composite oxide powder containing the support obtained in step S1 is mixed uniformly with a modifier, pore-forming agent, and binder with a particle size of less than 200 nm according to the stoichiometric ratio. The mixture is then formed into particles by spray drying, extrusion molding, or sheet forming. These particles are then calcined in flowing air at 300-400℃ for 1.0-2.0 h and 500-600℃ for 3.0-5.0 h to obtain the catalyst. x (M 1.00 X a Y b O c )- y G / z Z particles.

8. The method according to any one of claims 4-7, characterized in that, The catalyst x (M 1.00 X a Y b O c )- y G / z Z consists of microspheres with a diameter of 30-300 μm, cylindrical particles with a diameter of 2-5 mm and a length of 3-8 mm, or clover-shaped particles with a diameter of 2-5 mm and a length of 3-8 mm.

9. The application of the catalyst according to any one of claims 1-3 in the catalytic cracking reaction of ethylene glycol dialkyl ethers to prepare vinylalkyl ethers, characterized in that, The reactor feed for the reaction includes a dilution gas; the reaction conditions are a temperature of 350–480°C, a pressure of 0.01–1.00 MPa, and a liquid hourly space velocity (WHSV) of 0.1–5.0 h⁻¹ for the ethylene glycol dialkyl ether feed. -1 Volumetric hourly space velocity (VHSV) of feed gas and dilution gas is 0~5000 h⁻¹ -1 .

10. A method for preparing vinyl alkyl ethers, characterized in that, The method includes preparing vinyl alkyl ethers by catalyzing the cracking reaction of ethylene glycol dialkyl ethers using a catalyst according to any one of claims 1-3.

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