A dehydrogenation catalyst, a method for preparing the same, and use thereof

Abstract

The present application provides a kind of dehydrogenation catalyst and its preparation method and use, the dehydrogenation catalyst includes carrier Z and copper, chromium, element X and element Y supported on the carrier Z;With the total mass of dehydrogenation catalyst as benchmark, the copper content is 1-15wt%;The chromium content is 0.1-5wt%;The element X includes any one or at least two combinations of zinc, gallium, indium, tin or bismuth;Element Y includes any one or at least two combinations of magnesium, calcium, strontium or barium.The dehydrogenation catalyst of the present application uses copper as active component, chromium, element X and element Y as auxiliary, improves the selectivity of dehydrogenation catalyst to main product of dehydrocyclization, reaction by-product is less, anti-carbon, anti-sintering;And with low chromium and low copper design to reach moderate dehydrogenation activity, avoid reaction too concentrated and cold point too low, can be used for diol efficient dehydrogenation reaction, has large-scale popularization prospect.

Description

Technical Field

[0001] This invention relates to the field of chemical catalysis technology, and in particular to a dehydrogenation catalyst, its preparation method, and its uses. Background Technology

[0002] Industrially, the main methods for producing γ-butyrolactone are the 1,4-butanediol dehydrogenation method and the maleic anhydride hydrogenation method. The maleic anhydride hydrogenation process is relatively complex, producing products including 1,4-butanediol, γ-butyrolactone, and tetrahydrofuran, and there is currently no industrial catalyst specifically for the production of γ-butyrolactone. The 1,4-butanediol dehydrogenation method, with its simple process and specific products, overcomes these shortcomings and is the mainstream process for γ-butyrolactone production.

[0003] Depending on the phase of the reactants, the dehydrogenation of 1,4-butanediol can be divided into liquid-phase dehydrogenation and gas-phase dehydrogenation. Liquid-phase dehydrogenation eliminates the need for raw material gasification, resulting in a simpler process, lower operating temperature, lower energy consumption, and less restriction by the thermodynamic equilibrium of the generated hydrogen gas. However, because this reaction is endothermic, the conversion rate is low at low temperatures, and the generated aldehyde intermediates are prone to polymerization into high-boiling byproducts, leading to low selectivity for γ-butyrolactone, difficulty in product separation, and the risk of catalyst deactivation (see "Research and Development of Catalysts for the Liquid-Phase Dehydrogenation Cyclone Synthesis of γ-Butyrolactone," Lin Yanhua, Doctoral Dissertation, Zhejiang University, 1996). Early domestic pilot-scale trials at Shanghai Wusong Chemical Plant (see "Synthesis and Application of γ-Butyrolactone," Xiao Youqing et al., Shanghai Chemical Industry, Vol. 20, No. 1, pp. 27-30) were not entirely successful.

[0004] Currently, the dehydrogenation of 1,4-butanediol primarily employs a gas-phase dehydrogenation method. Preheated 1,4-butanediol is mixed with a portion of recycled hot steam, then heated to the required temperature before entering a fixed-bed reactor. The reaction proceeds under heating, hydrogen-containing, atmospheric, or pressurized conditions to yield crude γ-butyrolactone. This process was first industrialized in Germany in 1946 by IG-Farbenindustrie AG and has since been widely adopted.

[0005] Industrial catalysts for the dehydrogenation of 1,4-butanediol to γ-butyrolactone mostly use copper as the active component and hexavalent chromium as a key promoter. For example, CN1054843A discloses a method for preparing N-methylpyrrolidone, using a co-precipitation method of chromium anhydride and other metal nitrates to prepare a Cu-Zn-Cr-Zr catalyst; CN115106094A discloses a catalyst for catalyzing the dehydrogenation of alcohols, its preparation method, and its application, using a method of separately precipitating copper-containing mixed salts and Cr(VI)-containing mixed salts and then mixing them to prepare the catalyst. However, hexavalent chromium species are often soluble in water, which can easily cause environmental problems in the catalyst production process. The precipitation reaction of hexavalent chromium species with other metal ions is also difficult to precisely control and regulate.

[0006] Given the significant environmental risks and complex catalyst preparation process associated with using hexavalent chromium, researchers have attempted to replace it with trivalent chromium. CN1081948A discloses a catalyst for the gas-phase dehydrogenation of 1,4-butanediol to γ-butyrolactone, using chromium nitrate as the chromium source and co-precipitating it with other metal salts to obtain a Cu-Cr-Mn-Ba series catalyst. However, the solubility product constant K of chromium hydroxide in aqueous solution is problematic. sp Generally, the concentration of chromium species is higher than that of other required metal hydroxides, causing chromium species to precipitate first and resulting in uneven dispersion. CN1301984A discloses a catalytic synthesis method for γ-butyrolactone, which uses the sol-gel method to synthesize a Cu-Cr-Si catalyst, attempting to disperse the co-precipitated copper and chromium species on a SiO2 support, but it does not fundamentally solve the problem of the difficulty in simultaneous precipitation of metal species.

[0007] Therefore, developing a dehydrogenation catalyst that achieves efficient dehydrogenation and cyclization of diols using as little trivalent chromium as an auxiliary agent is an urgent problem to be solved in this field. Summary of the Invention

[0008] In view of the problems existing in the prior art, the present invention provides a dehydrogenation catalyst, its preparation method and uses. The dehydrogenation catalyst uses copper as the active component and chromium, element X and element Y as promoters, which improves the selectivity of the dehydrogenation cyclization main product, reduces reaction by-products, and resists coking and sintering. Moreover, the low chromium and low copper design achieves moderate dehydrogenation activity, avoids excessive reaction concentration and low cooling point, reduces the formation of high-boiling by-products, and can be used for efficient dehydrogenation reaction of diols, making it suitable for large-scale promotion.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a dehydrogenation catalyst, the dehydrogenation catalyst comprising a support Z and copper, chromium, element X and element Y supported on the support Z;

[0011] Based on the total mass of the dehydrogenation catalyst, the copper content is 1-15 wt%; the chromium content is 0.1-5 wt%; element X includes any one or a combination of at least two of zinc, gallium, indium, tin, or bismuth; and element Y includes any one or a combination of at least two of magnesium, calcium, strontium, or barium.

[0012] The dehydrogenation catalyst of this invention uses copper as the active component and chromium, element X, and element Y as promoters, which exist in the catalyst in the form of oxides or elements. Element X is an electronic promoter of copper, which can improve the electron cloud density distribution of copper atoms at active sites and weaken their adsorption capacity for raw material and product molecules, thereby reducing hydrogenolysis and hydrogenation side reactions that require longer reaction times. Element Y is a mild alkaline promoter, which suppresses the acidity of the catalyst and reduces dehydration side reactions while avoiding excessive impact on the catalytic activity of copper. Moreover, there is a synergistic effect between element X and element Y, with element Y contributing to the uniform dispersion of element X on the surface of support Z. Support Z is preferably a porous structure with a high specific surface area to expose more active sites. The dehydrogenation catalyst of this invention has a copper content of 1-15 wt% and a chromium content of 0.1-5 wt%. The low chromium and low copper design achieves moderate dehydrogenation activity, avoids excessive reaction concentration and excessively low cold point, reduces the formation of high-boiling side products, lowers catalyst costs, and improves the anti-sintering ability of the dehydrogenation catalyst.

[0013] The copper content described in this invention is 1 to 15 wt%, for example, it can be 1 wt%, 2 wt%, 3 wt%, 5 wt%, 10 wt%, 12 wt%, or 15 wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0014] The chromium content is 0.1 to 5 wt%, for example, it can be 0.1 wt%, 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, or 5 wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0015] The element X described in this invention includes any one or a combination of at least two of zinc, gallium, indium, tin or bismuth, wherein typical but non-limiting combinations include combinations of zinc and gallium, combinations of indium and tin or combinations of bismuth and zinc.

[0016] The element Y described in this invention includes any one or a combination of at least two of magnesium, calcium, strontium, or barium, wherein typical but non-limiting combinations include combinations of magnesium and calcium, combinations of strontium and barium, or combinations of magnesium and strontium.

[0017] Preferably, the copper content is 5 to 12 wt% based on the total mass of the dehydrogenation catalyst, for example, it can be 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10.5 wt%, or 12 wt%, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0018] Preferably, the chromium content is 0.2 to 4 wt% based on the total mass of the dehydrogenation catalyst, for example, it can be 0.2 wt%, 0.5 wt%, 0.8 wt%, 1 wt%, 2 wt%, 3 wt%, or 4 wt%, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0019] Preferably, based on the total mass of the dehydrogenation catalyst, the content of element X is 0.1 to 20 wt%, for example, it can be 0.1 wt%, 0.5 wt%, 1 wt%, 5 wt%, 10 wt%, 15 wt%, or 20 wt%, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0020] Preferably, based on the total mass of the dehydrogenation catalyst, the content of element Y is 0.1 to 10 wt%, for example, it can be 0.1 wt%, 0.5 wt%, 1 wt%, 3 wt%, 5 wt%, 8 wt%, or 10 wt%, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0021] Preferably, based on the total mass of the dehydrogenation catalyst, the Z content of the support is 50-95 wt%, for example, it can be 50 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, 93 wt%, or 95 wt%, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0022] Preferably, the carrier Z comprises any one or a combination of at least two of alumina, silica, inorganic carbon, bentonite, sepiolite, diatomite, kaolin, MFI molecular sieve, *BEA molecular sieve, MOR molecular sieve, ERI molecular sieve, or FAU molecular sieve. Typical but non-limiting combinations include a combination of alumina and silica, a combination of inorganic carbon and bentonite, a combination of sepiolite and diatomite, a combination of kaolin and MFI molecular sieve, or a combination of *BEA molecular sieve and MOR molecular sieve.

[0023] The *BEA molecular sieve described in this invention is a well-known concept in the art.

[0024] In a second aspect, the present invention also provides a method for preparing a dehydrogenation catalyst as described in the first aspect, the method comprising the following steps:

[0025] S1. After mixing and stirring the carrier Z or its precursor with the first solvent, add the copper precursor and mix to obtain dispersion 1; mix the precursors of X and Y with the second solvent to obtain dispersion 2.

[0026] S2. Mix the dispersion 1 and the dispersion 2 to obtain a mixed dispersion, and then subject it to a first drying and a first calcination treatment to obtain a catalyst precursor.

[0027] And / or, mix dispersion 1 and dispersion 2 to obtain a mixed dispersion, filter the mixed dispersion, and subject the resulting precipitate to a second drying and a first calcination treatment in sequence to obtain a catalyst precursor;

[0028] S3. The chromium precursor is loaded onto the catalyst precursor by impregnation, and after a third drying, it is subjected to a second calcination treatment in an oxidizing atmosphere.

[0029] S4. Catalyst forming process to obtain the dehydrogenation catalyst.

[0030] The dehydrogenation catalyst preparation method of the present invention uses a more chromium-friendly precursor, Cr(III) species, which is introduced last in the preparation process. This allows for easy and sufficient contact with the surface of the active component, copper, resulting in better selectivity of the dehydrogenation catalyst, a significant reduction in the amount of chromium used, and no waste liquid generated, making it more environmentally friendly.

[0031] Preferably, the precursor of the carrier Z in step S1 includes any one or a combination of at least two of aluminum nitrates, aluminates, C1-C8 alkoxides of aluminum, aluminum hydroxides, and hydrated oxides of aluminum, and / or any one or a combination of at least two of silicic acid, silicates, aluminosilicates, aluminosilicates, silica sols, aluminosilicate sols, or organosilicon compounds in which at least one organic group is directly bonded to a silicon atom. Typical but non-limiting combinations include combinations of C1-C8 alkoxides of aluminum and aluminum hydroxides, combinations of hydrated oxides of aluminum and silicic acid, combinations of silicates and aluminosilicates, or combinations of aluminosilicate sols and organosilicon compounds in which at least one organic group is directly bonded to a silicon atom.

[0032] The aluminum C1 to C8 alkoxides may be, for example, C1 alkoxides, C3 alkoxides, C5 alkoxides, C7 alkoxides, or C8 alkoxides.

[0033] Preferably, the copper precursor comprises any one or a combination of at least two of copper nitrates, copper carbonates, copper bicarbonates, copper basic carbonates, copper hydroxides, or organocopper complexes, wherein typical but non-limiting combinations include combinations of copper nitrates and copper carbonates, combinations of copper bicarbonates and copper basic carbonates, or combinations of copper hydroxides and organocopper complexes.

[0034] Preferably, the organocopper complex comprises any one or a combination of at least two of organocopper complexes having an ether bond, hydroxyl group, carbonyl group, carboxyl group, ester group, amino group, imino group, nitro group, nitroso group, cyano group, or amide group. Typical but non-limiting combinations include combinations of organocopper complexes having an ether bond and organocopper complexes having a hydroxyl group, combinations of organocopper complexes having a carbonyl group and organocopper complexes having a carboxyl group, combinations of organocopper complexes having an ether bond and organocopper complexes having an ester group, or combinations of organocopper complexes having an imino group and organocopper complexes having an amide group.

[0035] Preferably, the precursor of element X includes any one or a combination of at least two of zinc precursor, gallium precursor, indium precursor, tin precursor or bismuth precursor, wherein typical but non-limiting combinations include combinations of zinc and gallium precursors, combinations of indium and tin precursors, combinations of bismuth precursors, zinc and gallium precursors or combinations of indium and bismuth precursors.

[0036] Preferably, the zinc precursor comprises any one or a combination of at least two of zinc nitrate, zinc carbonate, zinc bicarbonate, zinc basic carbonate, zinc hydroxide, or organozinc complex, wherein typical but non-limiting combinations include combinations of zinc nitrate and zinc carbonate, combinations of zinc bicarbonate and zinc basic carbonate, and combinations of zinc hydroxide and organozinc complex.

[0037] Preferably, the organozinc complex comprises any one or a combination of at least two of organozinc complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups. Typical but non-limiting combinations include combinations of organozinc complexes having alkyl groups and organozinc complexes having ether groups, combinations of organozinc complexes having hydroxyl groups and organozinc complexes having ester groups, combinations of organozinc complexes having imino groups and organozinc complexes having nitro groups, combinations of organozinc complexes having cyano groups and organozinc complexes having alkyl groups, or combinations of organozinc complexes having amide groups and organozinc complexes having amino groups.

[0038] Preferably, the gallium precursor comprises any one or a combination of at least two of gallium nitrate, gallium carbonate, gallium bicarbonate, gallium basic carbonate, gallium hydroxide, or organogallium complex, wherein typical but non-limiting combinations include combinations of gallium nitrate and gallium bicarbonate, combinations of gallium carbonate and gallium basic carbonate, or combinations of gallium hydroxide and organogallium complex.

[0039] Preferably, the organogallium complex comprises any one or a combination of at least two of organogallium complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups. Typical but non-limiting combinations include combinations of organogallium complexes having alkyl groups and organogallium complexes having ether groups, combinations of organogallium complexes having hydroxyl groups and organogallium complexes having ester groups, combinations of organogallium complexes having imino groups and organogallium complexes having nitro groups, combinations of organogallium complexes having cyano groups and organogallium complexes having alkyl groups, or combinations of organogallium complexes having amide groups and organogallium complexes having amino groups.

[0040] Preferably, the indium precursor comprises any one or a combination of at least two of indium nitrate, indium carbonate, indium bicarbonate, indium basic carbonate, indium hydroxide, or organoindium complex, wherein typical but non-limiting combinations include combinations of indium nitrate and indium bicarbonate, combinations of indium carbonate and indium basic carbonate, or combinations of tin hydroxide and organotin complex.

[0041] Preferably, the organoindium complex comprises any one or a combination of at least two of organoindium complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups. Typical but non-limiting combinations include combinations of organoindium complexes having alkyl groups and organoindium complexes having ether groups, combinations of organoindium complexes having hydroxyl groups and organoindium complexes having ester groups, combinations of organoindium complexes having imino groups and organoindium complexes having nitro groups, combinations of organoindium complexes having cyano groups and organoindium complexes having alkyl groups, or combinations of organoindium complexes having amide groups and organoindium complexes having amino groups.

[0042] Preferably, the tin precursor comprises any one or a combination of at least two of tin nitrates, tin carbonates, tin bicarbonates, tin basic carbonates, tin hydroxides, or organotin complexes, wherein typical but non-limiting combinations include combinations of tin nitrates and tin bicarbonates, combinations of tin carbonates and tin basic carbonates, or combinations of tin hydroxides and organotin complexes.

[0043] Preferably, the organotin complex comprises any one or a combination of at least two of organotin complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups. Typical but non-limiting combinations include combinations of organotin complexes having alkyl and ether groups, combinations of organotin complexes having hydroxy and ester groups, combinations of organotin complexes having imino and nitro groups, combinations of organotin complexes having cyano and alkyl groups, or combinations of organotin complexes having amide and amino groups.

[0044] Preferably, the bismuth precursor comprises any one or a combination of at least two of bismuth nitrate, bismuth carbonate, bismuth bicarbonate, bismuth basic carbonate, bismuth hydroxide, or organobismuth complex, wherein typical but non-limiting combinations include combinations of bismuth nitrate and bismuth bicarbonate, combinations of bismuth carbonate and bismuth basic carbonate, or combinations of bismuth hydroxide and organobismuth complex.

[0045] Preferably, the organobismuth complex comprises any one or a combination of at least two organobismuth complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups. Typical but non-limiting combinations include combinations of organobismuth complexes having alkyl groups and organobismuth complexes having ether groups, combinations of organobismuth complexes having hydroxyl groups and organobismuth complexes having ester groups, combinations of organobismuth complexes having imino groups and organobismuth complexes having nitro groups, combinations of organobismuth complexes having cyano groups and organobismuth complexes having alkyl groups, or combinations of organobismuth complexes having amide groups and organobismuth complexes having amino groups.

[0046] Preferably, the precursor of Y includes any one or a combination of at least two of magnesium precursor, calcium precursor, strontium precursor or barium precursor, wherein typical but non-limiting combinations include a combination of magnesium precursor and calcium precursor, a combination of strontium precursor and barium precursor, a combination of magnesium precursor and strontium precursor or barium precursor magnesium precursor or a combination of calcium precursor and barium precursor.

[0047] Preferably, the magnesium precursor comprises any one or a combination of at least two of magnesium nitrate, magnesium carbonate, magnesium bicarbonate, magnesium basic carbonate, magnesium hydroxide, or organomagnesium complex, wherein typical but non-limiting combinations include combinations of magnesium nitrate and magnesium carbonate, combinations of magnesium basic carbonate and magnesium hydroxide, or combinations of magnesium bicarbonate and organomagnesium complex.

[0048] Preferably, the organomagnesium complex comprises any one or a combination of at least two of organomagnesium complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups. Typical but non-limiting combinations include combinations of organomagnesium complexes with alkyl and ether groups, organomagnesium complexes with hydroxyl and ester groups, organomagnesium complexes with imino and nitro groups, organomagnesium complexes with cyano and alkyl groups, or organomagnesium complexes with amide and amino groups.

[0049] Preferably, the calcium precursor comprises any one or a combination of at least two of calcium nitrate, calcium carbonate, calcium bicarbonate, calcium basic carbonate, calcium hydroxide, or an organic calcium complex, wherein typical but non-limiting combinations include a combination of calcium nitrate and calcium carbonate, a combination of calcium basic carbonate and calcium hydroxide, or a combination of calcium basic carbonate and an organic calcium complex.

[0050] Preferably, the organic calcium complex comprises any one or a combination of at least two of organic calcium complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups. Typical but non-limiting combinations include combinations of organic calcium complexes with alkyl groups and organic calcium complexes with ether groups, combinations of organic calcium complexes with hydroxyl groups and organic calcium complexes with ester groups, combinations of organic calcium complexes with imino groups and organic calcium complexes with nitro groups, combinations of organic calcium complexes with cyano groups and organic calcium complexes with alkyl groups, or combinations of organic calcium complexes with amide groups and organic calcium complexes with amino groups.

[0051] Preferably, the strontium precursor comprises any one or a combination of at least two of strontium nitrate, strontium carbonate, strontium bicarbonate, strontium basic carbonate, strontium hydroxide, or organostrontium complex, wherein typical but non-limiting combinations include combinations of strontium nitrate and strontium bicarbonate, combinations of strontium carbonate and strontium basic carbonate, or combinations of strontium hydroxide and organostrontium complex.

[0052] Preferably, the organostrontium complex comprises any one or a combination of at least two organostrontium complexes having an alkyl group, an ether bond, a hydroxyl group, a carbonyl group, a carboxyl group, an ester group, an amino group, an imino group, a nitro group, a nitroso group, a cyano group, or an amide group. Typical but non-limiting combinations include combinations of organostrontium complexes having an alkyl group and organostrontium complexes having an ether bond, combinations of organostrontium complexes having a hydroxyl group and organostrontium complexes having an ester group, combinations of organostrontium complexes having an imino group and organostrontium complexes having a nitro group, combinations of organostrontium complexes having a cyano group and organostrontium complexes having an alkyl group, or combinations of organostrontium complexes having an amide group and organostrontium complexes having an amino group.

[0053] Preferably, the barium precursor comprises any one or a combination of at least two of barium nitrate, barium carbonate, barium bicarbonate, barium basic carbonate, barium hydroxide, or organobarium complex, wherein typical but non-limiting combinations include combinations of barium nitrate and barium bicarbonate, combinations of barium carbonate and barium basic carbonate, or combinations of barium hydroxide and organobarium complex.

[0054] Preferably, the organobarium complex comprises any one or a combination of at least two organobarium complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups. Typical but non-limiting combinations include combinations of organobarium complexes having alkyl groups and organobarium complexes having ether groups, combinations of organobarium complexes having hydroxyl groups and organobarium complexes having ester groups, combinations of organobarium complexes having imino groups and organobarium complexes having nitro groups, combinations of organobarium complexes having cyano groups and organobarium complexes having alkyl groups, or combinations of organobarium complexes having amide groups and organobarium complexes having amino groups.

[0055] Preferably, the first solvent comprises any one or a combination of at least two of water, liquid ammonia, C1-C8 alcohols or C4-C10 hydrocarbons, wherein typical but non-limiting combinations include a combination of water and liquid ammonia, a combination of C1-C8 alcohols and C4-C10 hydrocarbons, a combination of water and C1-C8 alcohols, or a combination of C4-C10 hydrocarbons and liquid ammonia.

[0056] The C1-C8 alcohols mentioned in this invention may be, for example, C1 alcohols, C2 alcohols, C4 alcohols, C5 alcohols, C7 alcohols, or C8 alcohols; the C4-C10 hydrocarbons may be, for example, C4 hydrocarbons, C5 hydrocarbons, C7 hydrocarbons, C8 hydrocarbons, or C10 hydrocarbons.

[0057] The C4-C10 hydrocarbons described in this invention include C4-C10 alkanes, C4-C10 cycloalkanes, C4-C10 alkenes, C4-C10 alkynes, or C4-C10 aromatic hydrocarbons.

[0058] Preferably, the second solvent comprises any one or a combination of at least two of water, liquid ammonia, C1-C8 alcohols or C4-C10 hydrocarbons, wherein typical but non-limiting combinations include a combination of water and liquid ammonia, a combination of C1-C8 alcohols and C4-C10 hydrocarbons, a combination of water and C1-C8 alcohols, or a combination of C4-C10 hydrocarbons and liquid ammonia.

[0059] Preferably, the mixing temperature of dispersion 1 and dispersion 2 in step S2 is 10 to 90°C, for example, it can be 10°C, 20°C, 30°C, 50°C, 70°C, 80°C or 90°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0060] Preferably, the first drying method includes continuously heating the mixed dispersion at a temperature 1 to 10°C below the solvent boiling point, for example, 1°C, 3°C, 5°C, 8°C, 9°C, or 10°C, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0061] Evaporate the moisture until dry, then heat at 100-200°C, for example, 100°C, 120°C, 150°C, 170°C, 190°C or 200°C, but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0062] Heating time is 5 to 100 hours, for example, 5 hours, 10 hours, 30 hours, 50 hours, 70 hours, 90 hours or 100 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0063] Alternatively, the mixture can be heated and evaporated into a slurry, and then spray-dried at 120–250°C, for example, 120°C, 150°C, 160°C, 170°C, 180°C, 190°C, or 250°C, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0064] Preferably, the second drying method includes a temperature of 100 to 200°C, such as 100°C, 120°C, 150°C, 180°C, 190°C or 200°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0065] Heating time is 5 to 100 hours, for example, 5 hours, 10 hours, 30 hours, 50 hours, 70 hours, 90 hours or 100 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0066] Preferably, the first calcination treatment method includes a temperature of 200 to 800°C, for example, 200°C, 250°C, 300°C, 400°C, 500°C, 700°C or 800°C, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0067] Heating time is 1 to 20 hours, for example, 1 hour, 3 hours, 5 hours, 10 hours, 13 hours, 15 hours, or 20 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0068] Preferably, the chromium precursor in step S3 is any one or a combination of at least two of the following: Cr(III)-containing nitrates, Cr(III)-containing carbonates, Cr(III)-containing basic carbonates, or organic Cr(III) complexes; a combination of Cr(III)-containing nitrates and Cr(III)-containing carbonates; a combination of Cr(III)-containing basic carbonates and organic Cr(III) complexes; or a combination of Cr(III)-containing nitrates and Cr(III)-containing basic carbonates.

[0069] Preferably, the organic Cr(III) complex comprises any one or a combination of at least two of organic Cr(III) complexes having an ether bond, hydroxyl group, carbonyl group, carboxyl group, ester group, amino group, imino group, nitro group, nitroso group, cyano group, or amide group. Typical but non-limiting combinations include combinations of organic Cr(III) complexes with alkyl groups and organic Cr(III) complexes with ether bonds, combinations of organic Cr(III) complexes with hydroxyl groups and organic Cr(III) complexes with ester groups, combinations of organic Cr(III) complexes with imino groups and organic Cr(III) complexes with nitro groups, combinations of organic Cr(III) complexes with cyano groups and organic Cr(III) complexes with alkyl groups, or combinations of organic Cr(III) complexes with amide groups and organic Cr(III) complexes with amino groups.

[0070] Preferably, the impregnation solvent used for the chromium precursor includes any one or a combination of at least two of the following: water, nitric acid, liquid ammonia, C4-C10 aliphatic hydrocarbons or C1-C10 organic compounds, a combination of water and nitric acid, a combination of C4-C10 aliphatic hydrocarbons and C1-C10 organic compounds, or a combination of nitric acid and liquid ammonia.

[0071] Preferably, the C1-C10 organic compounds include any one or a combination of at least two of the following C1-C10 organic compounds: alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide. Typical but non-limiting combinations include combinations of C1-C10 organic compounds with alkyl groups and C1-C10 organic compounds with ether groups, combinations of C1-C10 organic compounds with hydroxyl groups and C1-C10 organic compounds with ester groups, combinations of C1-C10 organic compounds with imino groups and C1-C10 organic compounds with nitro groups, combinations of C1-C10 organic compounds with cyano groups and C1-C10 organic compounds with alkyl groups, or combinations of C1-C10 organic compounds with amide groups and C1-C10 organic compounds with amino groups.

[0072] The C4 to C10 aliphatic hydrocarbons described in this invention may be, for example, C4 aliphatic hydrocarbons, C5 aliphatic hydrocarbons, C7 aliphatic hydrocarbons, C8 aliphatic hydrocarbons, C9 aliphatic hydrocarbons, or C10 aliphatic hydrocarbons.

[0073] The C1 to C10 organic compounds mentioned in this invention may be, for example, C1 organic compounds, C3 organic compounds, C4 organic compounds, C5 organic compounds, C6 organic compounds, C8 organic compounds, or C10 organic compounds.

[0074] Preferably, the third drying method includes a temperature of 100 to 200°C, such as 100°C, 120°C, 140°C, 150°C, 170°C, 190°C or 200°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0075] Heating time is 5 to 100 hours, for example, 5 hours, 10 hours, 30 hours, 50 hours, 70 hours, 90 hours, or 100 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0076] Preferably, the catalyst forming process in step S4 includes tableting, extrusion, or ball rolling.

[0077] Preferably, the lubricant used in the tableting method includes high-purity graphite, and the amount of high-purity graphite is 0.1 to 3 wt%, for example, it can be 0.1 wt%, 0.5 wt%, 0.8 wt%, 1 wt%, 1.5 wt%, 2 wt%, or 3 wt%, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0078] Preferably, the post-compression treatment also includes a temperature of 200–800°C in an oxygen-containing atmosphere, such as 200°C, 250°C, 300°C, 400°C, 500°C, 700°C, or 800°C, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0079] The oxygen-containing atmosphere described in this invention refers to a gaseous atmosphere with an oxygen volume content greater than 5%.

[0080] The roasting time is 1 to 20 hours, for example, it can be 1 hour, 3 hours, 5 hours, 10 hours, 12 hours, 15 hours or 20 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0081] Preferably, the catalyst after tableting is a cylinder with a diameter of 2 to 10 mm, such as 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 8 mm or 10 mm, but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0082] The height of the cylinder is 2 to 10 mm, for example, it can be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 8 mm or 10 mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0083] Preferably, the binder used in the extrusion method includes silica sol, which is one of sodium silica sol, ammonia silica sol, acid silica sol or silica-alumina sol. The amount of silica sol used is 1 to 10 wt%, for example, it can be 1 wt%, 2 wt%, 3 wt%, 5 wt%, 8 wt%, 9 wt% or 10 wt%, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0084] Preferably, the extrusion process further includes heating at 100-200°C, for example, 100°C, 120°C, 150°C, 170°C, 180°C, 190°C or 200°C, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0085] 5 to 100h, for example, it can be 5h, 10h, 30h, 50h, 70h, 90h or 100h, but it is not limited to the listed values. Other unlisted values ​​within this range also apply.

[0086] Then, calcine at 200–800°C in an oxygen-containing atmosphere. For example, it can be 200°C, 250°C, 300°C, 400°C, 500°C, 700°C, or 800°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0087] The oxygen-containing atmosphere described in this invention refers to a gaseous atmosphere with an oxygen volume content greater than 5%.

[0088] The range is 1 to 20 hours, for example, it can be 1 hour, 3 hours, 5 hours, 10 hours, 12 hours, 15 hours, or 20 hours, but it is not limited to the listed values. Other unlisted values ​​within this range also apply.

[0089] Preferably, the catalyst after extrusion is in the form of strips, and the diameter of the strips is 2 to 10 mm, for example, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 8 mm or 10 mm, etc., but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0090] The length of the strip is 2 to 10 mm, for example, it can be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 8 mm or 10 mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0091] Preferably, the binder used in the ball rolling method includes silica sol, which is any one of sodium silica sol, ammoniacal silica sol, acidic silica sol, or silica-alumina sol. The amount of silica sol used is 1 to 10 wt%, for example, it can be 1 wt%, 2 wt%, 3 wt%, 5 wt%, 8 wt%, 9 wt%, or 10 wt%, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0092] Preferably, the ball rolling process further includes heating at 100-200°C, for example, 100°C, 120°C, 150°C, 170°C, 180°C, 190°C or 200°C, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0093] 5 to 100h, for example, it can be 5h, 10h, 30h, 50h, 70h, 90h or 100h, but it is not limited to the listed values. Other unlisted values ​​within this range also apply.

[0094] Then, calcine at 200–800°C in an oxygen-containing atmosphere. For example, it can be 200°C, 250°C, 300°C, 400°C, 500°C, 700°C, or 800°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0095] The oxygen-containing atmosphere described in this invention refers to a gaseous atmosphere with an oxygen volume content greater than 5%.

[0096] The range is 1 to 20 hours, for example, it can be 1 hour, 3 hours, 5 hours, 10 hours, 12 hours, 15 hours, or 20 hours, but it is not limited to the listed values. Other unlisted values ​​within this range also apply.

[0097] Preferably, the catalyst treated by the spherical rolling method is a sphere with a diameter of 2 to 8 mm, such as 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm or 8 mm, but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0098] As a preferred technical solution of the present invention, the preparation method includes the following steps:

[0099] S1. After mixing and stirring the carrier Z or its precursor with the first solvent, add the copper precursor and mix to obtain dispersion 1; mix the precursors of X and Y with the second solvent to obtain dispersion 2.

[0100] S2. The dispersion 1 and the dispersion 2 are mixed at a temperature of 10-90°C to obtain a mixed dispersion, which is then subjected to a first drying and a first calcination treatment to obtain a catalyst precursor.

[0101] And / or, mix dispersion 1 and dispersion 2 to obtain a mixed dispersion, filter the mixed dispersion, and subject the resulting precipitate to a second drying and a first calcination treatment in sequence to obtain a catalyst precursor;

[0102] The first drying method includes continuously heating the mixed dispersion at a temperature 1 to 10°C below the solvent boiling point to evaporate the water to dryness, and then heating it at 100 to 200°C for 5 to 100 hours; or heating and evaporating the mixed dispersion into a slurry, and then spray drying it at 120 to 250°C.

[0103] The second drying method includes heating at a temperature of 100–200°C for 5–100 hours;

[0104] The first calcination treatment method includes heating at a temperature of 200–800°C for 1–20 hours;

[0105] S3. The chromium precursor is loaded onto the catalyst precursor by impregnation, and after a third drying, it is subjected to a second calcination treatment in an oxidizing atmosphere.

[0106] The third drying method includes heating at a temperature of 100–200°C for 5–100 hours;

[0107] S4. Catalyst forming process to obtain the dehydrogenation catalyst;

[0108] The catalyst forming process includes tableting, extrusion, or ball rolling.

[0109] The lubricant used in the tableting method includes high-purity graphite, and the amount of high-purity graphite used is 0.1-3 wt%.

[0110] Post-compression treatment also includes calcination at 200–800°C for 1–20 h in an oxygen-containing atmosphere;

[0111] The catalyst after tableting is cylindrical, with a diameter of 2-10 mm and a height of 2-10 mm.

[0112] The binder used in the extrusion method includes silica sol, which is any one of sodium silica sol, ammonia silica sol, acid silica sol or aluminosilicate sol, and the amount of silica sol used is 1 to 10 wt%.

[0113] After extrusion, the process also includes heating at 100–200℃ for 5–100 hours, followed by calcination at 200–800℃ for 1–20 hours in an oxygen-containing atmosphere;

[0114] The catalyst processed by the extrusion method is in the form of strips, the diameter of which is 2-10 mm and the length of which is 2-10 mm.

[0115] The binder used in the ball rolling method includes silica sol, which is one of sodium silica sol, ammonia silica sol, acid silica sol or aluminosilicate sol, and the amount of silica sol used is 1 to 10 wt%.

[0116] After the spherical treatment, the process also includes heating at 100-200℃ for 5-100 hours, followed by calcination at 200-800℃ for 1-20 hours in an oxygen-containing atmosphere;

[0117] The catalyst treated by the rolling ball method is a sphere with a diameter of 2-8 mm.

[0118] Thirdly, the present invention also provides the use of the dehydrogenation catalyst as described in the first aspect, said dehydrogenation catalyst being used in the preparation of lactones from diol dehydrogenation reactions.

[0119] The diols include any one or at least two combinations of 1,3-propanediol, 1,4-butanediol, 1,4-pentanediol, 1,5-pentanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, or diethylene glycol and their derivatives. Typical but non-limiting combinations include combinations of 1,3-propanediol and 1,4-butanediol, combinations of 1,4-pentanediol and 1,5-pentanediol, or combinations of 1,4-hexanediol and 1,6-hexanediol. Preferably, it includes any one or at least two combinations of 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, or diethylene glycol and their derivatives.

[0120] In the derivatives described in this invention, at least one hydrogen atom bonded to a carbon atom is substituted by an alkyl group, an ether bond, a hydroxyl group, a carbonyl group, a carboxyl group, an ester group, an amino group, an imino group, a nitro group, a nitroso group, a cyano group, an amide group, or an aryl group.

[0121] Preferably, the raw material for the dehydrogenation reaction is a diol, and the dehydrogenation reaction process is as follows: the diol is mixed with hydrogen and vaporized, and then dehydrogenated and cyclized to generate the corresponding lactone.

[0122] Preferably, the temperature of the dehydrogenation reaction is 180 to 350°C, for example, it can be 180°C, 190°C, 200°C, 220°C, 250°C, 280°C or 350°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0123] Preferably, the mass hourly space velocity (MSV) of the dehydrogenation reaction is 0.1–10 h⁻¹. -1 For example, it could be 0.1h -1 0.5h -1 1h -1 3h -1 5h -1 8h -1 9h -1 or 10h -1 This applies to, but is not limited to, the listed values; other unlisted values ​​within this range also apply.

[0124] Preferably, the dehydrogenation reaction is a hydrogen-induced reaction, and the molar ratio of hydrogen to alcohol is (1-30):1, for example, it can be 1:1, 3:1, 5:1, 10:1, 15:1, 20:1 or 30:1, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0125] Preferably, the pressure of the dehydrogenation reaction is 0.01 to 1.0 MPaG, for example, it can be 0.01 MPaG, 0.05 MPaG, 0.08 MPaG, 0.1 MPaG, 0.3 MPaG, 0.5 MPaG, 0.8 MPaG or 1.0 MPaG, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0126] The dehydrogenation catalyst described in this invention can be adapted to a high reaction pressure range (0.01–1.0 MPaG) by adjusting the dehydrogenation reaction temperature, mass hourly space velocity, and hydrogen-to-ethanol ratio. It exhibits low reaction byproducts, resistance to coking and sintering, and good catalytic activity, selectivity, and stability of the dehydrogenation main product. The reaction requires less recycled hydrogen and has a smaller volume, which can increase the unit load, achieve economies of scale, and reduce production costs.

[0127] Compared with the prior art, the present invention has at least the following beneficial effects:

[0128] (1) The introduction of promoter element X in the dehydrogenation catalyst provided by the present invention not only improves the selectivity of the dehydrogenation catalyst for the main dehydrogenation cyclization product, but also has a physical spatial confinement effect, which further improves the anti-sintering ability; the promoter element Y with moderate alkalinity suppresses the dehydration side reaction and has little effect on the dehydrogenation activity of the dehydrogenation catalyst. Element Y also helps the element X to be uniformly dispersed on the surface of the support Z. The two work together to comprehensively improve the performance of the dehydrogenation catalyst.

[0129] (2) The dehydrogenation catalyst provided by the present invention has a low amount of copper active component, moderate catalyst activity, avoids the problem of excessively low cold point in the catalytic dehydrogenation reaction, has few high-boiling by-products, high main product yield, long catalyst life and low catalyst cost.

[0130] (3) The preparation method of the dehydrogenation catalyst provided by the present invention pre-disperses the support Z or its precursor and the copper precursor, which improves the dispersion and anti-sintering ability of the active component in the dehydrogenation catalyst; the Cr(III) species are introduced last in the preparation process of the dehydrogenation catalyst, which is easy to fully contact with the surface of the active component, the dehydrogenation catalyst has better selectivity, the amount of chromium used is greatly reduced, and no waste liquid is generated, which is more environmentally friendly.

[0131] (4) The dehydrogenation catalyst provided by the present invention can adapt to the high reaction pressure range by adjusting the reaction temperature, space velocity and hydrogen-to-ethanol ratio. It has fewer reaction by-products, is resistant to coking and sintering, and exhibits good catalytic activity, selectivity and stability of the dehydrogenation main product. The amount of hydrogen used in the reaction cycle is small, which can increase the load of the equipment, achieve economies of scale, reduce production costs, and has broad application prospects. Attached Figure Description

[0132] Figure 1 The dehydrogenation catalyst prepared in Example 1 was subjected to a reaction pressure of 0.05 MPaG, a reaction temperature of 240 °C, and a mass hourly space velocity of 2.80 h⁻¹. -1 The conversion rate of 1,4-butanediol and the selectivity of γ-butyrolactone were evaluated over a thousand-hour period under a hydrogen-to-ethanol ratio of 10. Detailed Implementation

[0133] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0134] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0135] Example 1

[0136] This embodiment provides a method for preparing a dehydrogenation catalyst, the method comprising the following steps:

[0137] S1. Take 315.6g of 20% silica-alumina sol (containing 19.5% silica and 0.5% alumina) and add it to 500g of 5% ammonia water, stirring until homogeneous. Then add 17.9g of basic copper carbonate and stir to dissolve, obtaining dispersion 1. Take 45.5g of zinc nitrate hexahydrate and 29.5g of calcium nitrate tetrahydrate and add them to 500g of water, stirring to dissolve, obtaining dispersion 2.

[0138] S2. Mix dispersion 1 and dispersion 2 in parallel under thorough stirring, and heat to 60°C and stir for 2 hours. Then heat to 95°C and continue stirring to evaporate the mixed dispersion to dryness, taking care to absorb ammonia gas and prevent it from escaping into the air. Dry in an oven at 120°C and calcine at 300°C for 4 hours to obtain the catalyst precursor.

[0139] S3. Dissolve 14.2g of chromium oxalate in water to prepare a solution, impregnate 100g of the above catalyst precursor with an equal volume, and then dry at 120℃ for 10h to obtain catalyst powder.

[0140] S4. Add 2% silica sol and mix thoroughly, extrude into strips, and calcine at 550°C for 10 hours in a gas atmosphere with an oxygen volume content of 15% to obtain a strip-shaped dehydrogenation catalyst with a diameter of 2-4 mm and a length of 2-19 mm.

[0141] The dehydrogenation catalyst prepared in this embodiment has a composition of 10% Cu-10% Zn-5% Ca-2% Cr / support.

[0142] Example 2

[0143] This embodiment provides a method for preparing a dehydrogenation catalyst, the method comprising the following steps:

[0144] S1. Dissolve 332.5g of tetraethyl silicate in 500g of ethanol by stirring. Then add 37.7g of copper acetate monohydrate and stir to dissolve to obtain dispersion 1. Dissolve 3.8g of bismuth nitrate and 3.7g of barium acetate in 100g of water by stirring to obtain dispersion 2.

[0145] S2. Add dispersion 2 dropwise to dispersion 1 and mix thoroughly. Then heat to 60℃ and stir for 10 hours. Heat to 75℃ and continue stirring to evaporate the mixture into a slurry. Be careful to condense and collect the ethanol to prevent it from escaping into the air. Spray dry at 160℃ and calcine at 500℃ for 4 hours to obtain the catalyst precursor.

[0146] S3. Dissolve 17.6g of chromium acetate in water to prepare a solution, impregnate 100g of the above catalyst precursor with an equal volume, and then dry at 150℃ for 10h to obtain catalyst powder.

[0147] S4. Add 5% silica sol and mix thoroughly, roll into balls, and calcine at 650°C for 2 hours in a gas atmosphere with an oxygen volume content of 35% to obtain a spherical dehydrogenation catalyst with a diameter of 3-5 mm.

[0148] The dehydrogenation catalyst prepared in this embodiment has a composition of 12% Cu-2% Bi-2% Ba-4% Cr / support.

[0149] Example 3

[0150] This embodiment provides a method for preparing a dehydrogenation catalyst, the method comprising the following steps:

[0151] S1. Take 70g of ZSM-5 molecular sieve and add it to 500g of 10% ammonia water, stirring until well mixed. Then add 19.0g of copper nitrate trihydrate and stir to dissolve to obtain dispersion 1. Take 30.0g of gallium nitrate nonahydrate and 84.8g of magnesium nitrate hexahydrate and add them to 500g of water, stirring to dissolve to obtain dispersion 2.

[0152] S2. Mix dispersion 1 and dispersion 2 in parallel under thorough stirring, and heat to 60°C and stir for 2 hours. Then heat to 95°C and continue stirring to evaporate the mixed dispersion to dryness (be careful to absorb ammonia gas and prevent it from escaping into the air). Dry in an oven at 120°C and calcine at 300°C for 4 hours to obtain the catalyst precursor.

[0153] S3. Dissolve 3.8g of chromium nitrate nonahydrate in water to prepare a solution, impregnate 100g of the above catalyst precursor with an equal volume, and then dry at 180℃ for 10h to obtain catalyst powder.

[0154] S4. Add 4% graphite and mix thoroughly, press into tablets, and calcine at 650°C for 4 hours in a gas atmosphere with an oxygen volume content of 45% to obtain a cylindrical dehydrogenation catalyst with a diameter of 4-6 mm and a height of 4-6 mm.

[0155] The dehydrogenation catalyst prepared in this embodiment has the following composition: 5% Cu-5% Ga-8% Mg-0.5% Cr / support.

[0156] Example 4

[0157] This embodiment provides a method for preparing a dehydrogenation catalyst. Except for the calcination temperature of step S4 being 450°C, the preparation method is the same as that in Example 1.

[0158] Example 5

[0159] This embodiment provides a method for preparing a dehydrogenation catalyst. Except for the calcination temperature of 650°C in step S4, the preparation method is the same as that in Example 1.

[0160] Example 6

[0161] This embodiment provides a method for preparing a dehydrogenation catalyst. Except for the calcination temperature of 450°C in step S4 and the calcination atmosphere of 50% O2 / N2, the preparation method is the same as in Example 2.

[0162] Example 7

[0163] This embodiment provides a method for preparing a dehydrogenation catalyst. The preparation method is the same as in Example 3, except that in step S1, 30.0g gallium nitrate nonahydrate is replaced with 17.7g gallium isopropoxide and 500g water is replaced with 500g ethanol.

[0164] Example 8

[0165] This embodiment provides a method for preparing a dehydrogenation catalyst, the method comprising the following steps:

[0166] S1. Take 404.7g of silica sol (containing 20% ​​silica) and add it to 500g of 5% ammonia water, stirring until well mixed. Then add 17.9g of basic copper carbonate and stir to dissolve, obtaining dispersion 1. Take 0.8g of indium oxalate and 2.9g of calcium nitrate tetrahydrate and add them to 500g of water, stirring to dissolve, obtaining dispersion 2.

[0167] S2. Mix dispersion 1 and dispersion 2 in parallel under thorough stirring, and heat to 60°C and stir for 2 hours. Then heat to 95°C and continue stirring to evaporate the mixed dispersion to dryness, taking care to absorb ammonia gas and prevent it from escaping into the air. Dry in an oven at 120°C and calcine at 300°C for 4 hours to obtain the catalyst precursor.

[0168] S3. Dissolve 5.7g of chromium oxalate in water to prepare a solution, impregnate 100g of the above catalyst precursor with an equal volume, and then dry at 120℃ for 10h to obtain catalyst powder.

[0169] S4. Add 2% silica sol and mix thoroughly, extrude into strips, and calcine at 550°C for 10 hours in a gas atmosphere with an oxygen volume content of 15% to obtain a strip-shaped dehydrogenation catalyst with a diameter of 2-4 mm and a length of 2-19 mm.

[0170] The dehydrogenation catalyst prepared in this embodiment has the following composition: 10% Cu-0.5% In-0.5% Ca-0.8% Cr / support.

[0171] Example 9

[0172] This embodiment provides a method for preparing a dehydrogenation catalyst, the method comprising the following steps:

[0173] S1. Take 84.3g of silicon dioxide and add it to 500g of 10% ammonia water, stirring until well mixed. Then add 30.4g of copper nitrate trihydrate and stir to dissolve to obtain dispersion 1. Take 0.6g of tin tetrachloride and 5.3g of magnesium nitrate hexahydrate and add them to 500g of water, stirring to dissolve to obtain dispersion 2.

[0174] S2. Mix dispersion 1 and dispersion 2 in parallel under thorough stirring, and heat to 60°C and stir for 2 hours. Then heat to 95°C and continue stirring to evaporate the mixed dispersion to dryness (be careful to absorb ammonia gas and prevent it from escaping into the air). Dry in an oven at 120°C and calcine at 300°C for 4 hours to obtain the catalyst precursor.

[0175] S3. Dissolve 3.8g of chromium nitrate nonahydrate in water to prepare a solution, impregnate 100g of the above catalyst precursor with an equal volume, and then dry at 180℃ for 10h to obtain catalyst powder.

[0176] S4. Add 4% graphite and mix thoroughly, press into tablets, and calcine at 650°C for 4 hours in a gas atmosphere with an oxygen volume content of 45% to obtain a cylindrical dehydrogenation catalyst with a diameter of 4-6 mm and a height of 4-6 mm.

[0177] The dehydrogenation catalyst prepared in this embodiment has the composition of 8% Cu-0.2% Sn-0.5% Mg-0.5% Cr / support.

[0178] Comparative Example 1

[0179] This comparative example provides a method for preparing a dehydrogenation catalyst, the method comprising the following steps:

[0180] Take 100 mL of water and add 26.1 g of copper nitrate, 29.8 g of zinc nitrate, 11.6 g of chromic anhydride, and 13.4 g of zirconium nitrate, and stir well. Prepare a 1 M sodium carbonate solution. Introduce both solutions concurrently into a 20°C constant temperature water bath, stir vigorously, and control the pH to 6±1 to obtain a precipitate. After filtration and washing, dry at 110°C for 2 h, and calcine at 450°C for 24 h to obtain the catalyst. Then, introduce lubricating graphite and press it into shape... Cylindrical particles.

[0181] The dehydrogenation catalyst prepared in this comparative example is a commonly used Cu-Zn-Cr-Zr dehydrogenation catalyst in industry.

[0182] Comparative Example 2

[0183] This comparative example provides a method for preparing a dehydrogenation catalyst, which is the same as in Example 1 except that 45.5g of zinc nitrate hexahydrate is not added.

[0184] The dehydrogenation catalyst prepared in this comparative example does not contain element X.

[0185] Comparative Example 3

[0186] This comparative example provides a method for preparing a dehydrogenation catalyst, which is the same as in Example 1 except that 29.5g of calcium nitrate tetrahydrate is not added.

[0187] The dehydrogenation catalyst prepared in this comparative example does not contain element Y.

[0188] Comparative Example 4

[0189] This comparative example provides a method for preparing a dehydrogenation catalyst, which is the same as in Example 1 except that 45.5g of zinc nitrate hexahydrate and 29.5g of calcium nitrate tetrahydrate are not added simultaneously.

[0190] The dehydrogenation catalyst prepared in this comparative example does not contain elements X and Y.

[0191] Comparative Example 5

[0192] This comparative example provides a method for preparing a dehydrogenation catalyst, the method comprising the following steps:

[0193] S1. Take 70g of ZSM-5 molecular sieve and add it to 500g of 10% ammonia water, stirring until homogeneous. Then add 19.0g of copper nitrate trihydrate and stir to dissolve, obtaining dispersion 1. Take 30.0g of gallium nitrate nonahydrate, 84.8g of magnesium nitrate hexahydrate and 3.8g of chromium nitrate nonahydrate and add them to 500g of water, stirring to dissolve, obtaining dispersion 2.

[0194] S2. Mix dispersion 1 and dispersion 2 in parallel under thorough stirring, and heat to 60°C and stir for 2 hours. Then heat to 95°C and continue stirring to evaporate the mixed dispersion to dryness (note the absorption of ammonia gas and prevent it from escaping into the air). Dry in an oven at 120°C and calcine at 300°C for 4 hours to obtain catalyst powder.

[0195] S4. Add 4% graphite and mix thoroughly, press into tablets, and calcine at 650℃ for 4 hours to obtain a cylindrical dehydrogenation catalyst with a diameter of 2-5 mm and a height of 5-10 mm.

[0196] The preparation method of this comparative example introduces element X, element Y, and chromium simultaneously.

[0197] Comparative Example 6

[0198] This comparative example provides a method for preparing a dehydrogenation catalyst. The preparation method is the same as in Example 4, except that the amount of basic copper carbonate used in step S1 is 35.8g.

[0199] The dehydrogenation catalyst prepared in this comparative example contains 20% copper.

[0200] Comparative Example 7

[0201] This comparative example provides a method for preparing a dehydrogenation catalyst. The preparation method is the same as in Example 5, except that the amount of basic copper carbonate used in step S1 is 35.8g.

[0202] The dehydrogenation catalyst prepared in this comparative example contains 20% copper.

[0203] Comparative Example 8

[0204] This comparative example provides a method for preparing a dehydrogenation catalyst. The preparation method is the same as in Example 6, except that the amount of chromium oxalate used in step S3 is 26.4 g.

[0205] The dehydrogenation catalyst prepared in this comparative example contains 6% chromium.

[0206] 50g of the dehydrogenation catalyst prepared in the above examples and comparative examples was centrally packed into a stainless steel reaction tube with an inner diameter of 20mm and a length of 600cm. The reaction tube was filled with inert quartz sand packing material at the top and bottom. First, it was dried at 160℃ for 2 hours under a nitrogen atmosphere and a pressure of 0.3MPaG. Then, the atmosphere was switched to hydrogen for reduction, with the hydrogen concentration gradually increased from 0.5% to 100%, and the bed temperature gradually increased from 160℃ to 250℃. The exothermic reaction of the reduction was observed and the temperature rise of the reduction was controlled to be <20℃. Feeding began after 48 hours of reduction.

[0207] Using 1,4-butanediol as the reaction substrate, the mass hourly space velocity (WHSV) was 0.5 h⁻¹. -1 The reaction temperature was 230℃, the reaction pressure was 0.30 MPaG, and the hydrogen-to-ethanol ratio was 10 (molar ratio). The results are shown in Table 1.

[0208] Table 1

[0209]

[0210]

[0211] As can be seen from Table 1:

[0212] (1) The dehydrogenation catalyst and its preparation method provided by the present invention first mix and disperse the support Z or its precursor and the copper precursor, introduce the precursors of X and Y, and then introduce the chromium precursor to obtain the dehydrogenation catalyst with good 1,4-butanediol conversion and γ-butyrolactone selectivity, and low high-boiling product; the catalytic effect is better than that of the dehydrogenation catalyst commonly used in industry prepared by the preparation method of Comparative Example 1.

[0213] (2) It can be seen from the comprehensive comparison of Example 1 and Comparative Examples 2 to 4 that Comparative Examples 2 and 4 lack element X, the catalyst is prone to sintering, and the catalyst activity and main product selectivity decrease; when Comparative Examples 3 and 4 lack auxiliary agent Y, the main product selectivity decreases significantly and the heavy components increase significantly.

[0214] (3) It can be seen from the combined examples of Example 1 and Comparative Example 5 that when chromium is introduced too early, the utilization rate of chromium is low and the selectivity of the main product is low.

[0215] (4) As can be seen from Comparative Examples 6 and 7, when the amount of copper is too large, the catalyst in Comparative Example 6 has good activity under the low temperature calcination conditions, but the reaction is too concentrated, the cold point is too low, and the selectivity of the main product is poor; the catalyst in Comparative Example 7 is prone to sintering under high temperature calcination, and the catalyst activity is reduced.

[0216] (5) As can be seen from Comparative Example 8, when the amount of chromium is too high, the catalyst is too acidic and the content of heavy components is too high.

[0217] In Example 1, a dehydrogenation catalyst was prepared and first subjected to reduction treatment. 50g of the dehydrogenation catalyst prepared in the above examples and comparative examples was centrally packed into a stainless steel reaction tube with an inner diameter of 20mm and a length of 600cm. The reaction tube was filled with inert quartz sand packing material at both ends. First, it was dried at 160℃ for 2 hours under a nitrogen atmosphere and a pressure of 0.3MPa. Then, the reduction was switched to a hydrogen atmosphere, with the hydrogen concentration gradually increased from 0.5% to 100%, and the bed temperature gradually increased from 160℃ to 250℃. The exothermic reaction was observed, and the temperature rise was controlled to be <20℃. Feeding began after 48 hours of reduction. Then, using 1,4-butanediol as the reactant, the conversion rate of 1,4-butanediol, the selectivity of γ-butyrolactone, and the high-boiling point formation were tested under different reaction pressures, temperatures, space velocities, and hydrogen-to-ethanol ratios. The results are shown in Table 2.

[0218] Table 2

[0219]

[0220] As can be seen from Table 2, the dehydrogenation catalyst described in this invention exhibits good performance under the following conditions: reaction pressure of 0.05–1 MPaG, reaction temperature of 220–240 °C, and mass hourly space velocity of 0.22–2.80 h⁻¹. -1 Under conditions where the hydrogen-to-ethanol ratio is 10–26, the conversion rate of 1,4-butanediol can reach over 98.0%, the selectivity of γ-butyrolactone can reach over 98.6%, and the high-boiling product can reach less than 0.4 wt%.

[0221] The dehydrogenation catalyst prepared in Example 1 was subjected to a reaction pressure of 0.05 MPaG, a reaction temperature of 240 °C, and a mass hourly space velocity of 2.80 h⁻¹. -1A thousand-hour evaluation was conducted under a hydrogen-to-ethanol ratio of 10. The trend graphs of 1,4-butanediol conversion and γ-butyrolactone selectivity are shown below. Figure 1 As shown.

[0222] Depend on Figure 1 It can be seen that the 1,4-butanediol conversion rate of this dehydrogenation catalyst is basically stable, while the selectivity of γ-butyrolactone is slightly increased. The dehydrogenation catalyst prepared by the method described in this invention exhibits excellent stability.

[0223] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a dehydrogenation catalyst, characterized in that, The dehydrogenation catalyst includes a support Z and copper, chromium, element X and element Y supported on the support Z; Based on the total mass of the dehydrogenation catalyst, the copper content is 1~15wt%; the chromium content is 0.1~5wt%; the element X content is 0.1~20wt%; and the element Y content is 0.1~10wt%. The element X includes any one or a combination of at least two of zinc, gallium, indium, tin, or bismuth; The element Y includes any one or a combination of at least two of magnesium, calcium, strontium, or barium; The preparation method includes the following steps: S1. After mixing and stirring the carrier Z or its precursor with the first solvent, add the copper precursor and mix to obtain dispersion 1; mix the precursors of X and Y with the second solvent to obtain dispersion 2. S2. Mix the dispersion 1 and the dispersion 2 to obtain a mixed dispersion, and then subject it to a first drying and a first calcination treatment to obtain a catalyst precursor. And / or, mix dispersion 1 and dispersion 2 to obtain a mixed dispersion, filter the mixed dispersion, and subject the resulting precipitate to a second drying and a first calcination treatment in sequence to obtain a catalyst precursor; S3. The chromium precursor is loaded onto the catalyst precursor by impregnation, and after a third drying, it is subjected to a second calcination treatment in an oxidizing atmosphere. S4. Catalyst forming process to obtain the dehydrogenation catalyst.

2. The preparation method according to claim 1, characterized in that, The copper content is 5-12 wt% based on the total mass of the dehydrogenation catalyst.

3. The preparation method according to claim 1, characterized in that, The chromium content is 0.2~4 wt% based on the total mass of the dehydrogenation catalyst.

4. The preparation method according to claim 1, characterized in that, The carrier Z includes alumina, silicon dioxide, inorganic carbon, bentonite, sepiolite, diatomaceous earth, kaolin, and MFI molecular sieve. Any one or a combination of at least two of the following molecular sieves: BEA molecular sieve, MOR molecular sieve, ERI molecular sieve, or FAU molecular sieve.

5. The preparation method according to claim 1, characterized in that, The precursor of the carrier Z in step S1 includes any one or a combination of at least two of the following: aluminum nitrate, aluminate, C1-C8 alkoxide of aluminum, aluminum hydroxide, and hydrated oxide of aluminum; and / or any one or a combination of at least two of the following: silicic acid, silicate, aluminosilicate, aluminosilicate, silica sol, aluminosilicate sol, or an organosilicon compound in which at least one organic group is directly bonded to a silicon atom.

6. The preparation method according to claim 1, characterized in that, The copper precursor includes any one or a combination of at least two of the following: copper nitrate, copper carbonate, copper bicarbonate, copper basic carbonate, copper hydroxide, or organocopper complex.

7. The preparation method according to claim 6, characterized in that, The organocopper complex includes any one or a combination of at least two of organocopper complexes containing ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups.

8. The preparation method according to claim 1, characterized in that, The precursor of element X includes any one or a combination of at least two of zinc precursor, gallium precursor, indium precursor, tin precursor or bismuth precursor.

9. The preparation method according to claim 8, characterized in that, The zinc precursor includes any one or a combination of at least two of the following: zinc nitrate, zinc carbonate, zinc bicarbonate, zinc basic carbonate, zinc hydroxide, or organozinc complex.

10. The preparation method according to claim 9, characterized in that, The organozinc complexes include any one or a combination of at least two of organozinc complexes having alkyl, ether, hydroxy, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups.

11. The preparation method according to claim 8, characterized in that, The gallium precursor includes any one or a combination of at least two of gallium nitrate, gallium carbonate, gallium bicarbonate, gallium basic carbonate, gallium hydroxide, or organogallium complex.

12. The preparation method according to claim 11, characterized in that, The organogallium complex includes any one or a combination of at least two of organogallium complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups.

13. The preparation method according to claim 8, characterized in that, The indium precursor includes any one or a combination of at least two of the following: indium nitrate, indium carbonate, indium bicarbonate, indium basic carbonate, indium hydroxide, or organoindium complex.

14. The preparation method according to claim 13, characterized in that, The organoindium complex includes any one or a combination of at least two of organoindium complexes having alkyl, ether, hydroxy, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups.

15. The preparation method according to claim 8, characterized in that, The tin precursor includes any one or a combination of at least two of the following: tin nitrate, tin carbonate, tin bicarbonate, tin basic carbonate, tin hydroxide, or organotin complex.

16. The preparation method according to claim 15, characterized in that, The organotin complex includes any one or a combination of at least two of organotin complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups.

17. The preparation method according to claim 8, characterized in that, The bismuth precursor includes any one or a combination of at least two of the following: bismuth nitrate, bismuth carbonate, bismuth bicarbonate, bismuth basic carbonate, bismuth hydroxide, or organobismuth complex.

18. The preparation method according to claim 17, characterized in that, The organobismuth complex includes any one or a combination of at least two of organobismuth complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups.

19. The preparation method according to claim 1, characterized in that, The precursor of Y includes any one or a combination of at least two of the following: magnesium precursor, calcium precursor, strontium precursor, or barium precursor.

20. The preparation method according to claim 19, characterized in that, The magnesium precursor includes any one or a combination of at least two of the following: magnesium nitrate, magnesium carbonate, magnesium bicarbonate, magnesium basic carbonate, magnesium hydroxide, or organomagnesium complex.

21. The preparation method according to claim 20, characterized in that, The organomagnesium complex includes any one or a combination of at least two of organomagnesium complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups.

22. The preparation method according to claim 19, characterized in that, The calcium precursor includes any one or a combination of at least two of the following: calcium nitrate, calcium carbonate, calcium bicarbonate, calcium basic carbonate, calcium hydroxide, or organic calcium complex.

23. The preparation method according to claim 22, characterized in that, The organic calcium complex includes any one or a combination of at least two of the following: organic calcium complexes containing alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups.

24. The preparation method according to claim 19, characterized in that, The strontium precursor includes any one or a combination of at least two of the following: strontium nitrate, strontium carbonate, strontium bicarbonate, strontium basic carbonate, strontium hydroxide, or organostrontium complex.

25. The preparation method according to claim 24, characterized in that, The organostrontium complexes include any one or a combination of at least two of organostrontium complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups.

26. The preparation method according to claim 19, characterized in that, The barium precursor includes any one or a combination of at least two of the following: barium nitrate, barium carbonate, barium bicarbonate, barium basic carbonate, barium hydroxide, or organobarium complex.

27. The preparation method according to claim 26, characterized in that, The organobarium complex includes any one or a combination of at least two of organobarium complexes having alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups.

28. The preparation method according to claim 1, characterized in that, The first solvent includes any one or a combination of at least two of water, liquid ammonia, C1-C8 alcohols or C4-C10 hydrocarbons.

29. The preparation method according to claim 1, characterized in that, The second solvent includes any one or a combination of at least two of water, liquid ammonia, C1-C8 alcohols or C4-C10 hydrocarbons.

30. The preparation method according to claim 1, characterized in that, In step S2, the mixing temperature of dispersion 1 and dispersion 2 is 10~90℃.

31. The preparation method according to claim 1, characterized in that, The first drying method includes continuously heating the mixed dispersion at a temperature 1-10°C below the solvent boiling point to evaporate the water to dryness, and then heating it at 100-200°C for 5-100 hours; or heating and evaporating the mixed dispersion into a slurry, and then spray drying it at 120-250°C.

32. The preparation method according to claim 1, characterized in that, The second drying method includes heating at a temperature of 100~200℃ for 5~100h.

33. The preparation method according to claim 1, characterized in that, The first roasting treatment method includes heating at a temperature of 200~800℃ for 1~20h.

34. The preparation method according to claim 1, characterized in that, The chromium precursor mentioned in step S3 is any one or a combination of at least two of the following: Cr(III)-containing nitrates, Cr(III)-containing carbonates, Cr(III)-containing basic carbonates, or organic Cr(III) complexes.

35. The preparation method according to claim 34, characterized in that, The organic Cr(III) complexes include any one or a combination of at least two of the organic Cr(III) complexes containing ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, and amide groups.

36. The preparation method according to claim 1, characterized in that, The impregnation solvent used for the chromium precursor includes any one or a combination of at least two of the following: water, nitric acid, liquid ammonia, C4-C10 aliphatic hydrocarbons or C1-C10 organic compounds.

37. The preparation method according to claim 36, characterized in that, The C1-C10 organic compounds include any one or a combination of at least two of the following C1-C10 organic compounds: alkyl, ether, hydroxyl, carbonyl, carboxyl, ester, amino, imino, nitro, nitroso, cyano, or amide groups.

38. The preparation method according to claim 1, characterized in that, The third drying method includes heating at a temperature of 100~200℃ for 5~100h.

39. The preparation method according to claim 1, characterized in that, The catalyst forming process described in step S4 includes tableting, extrusion, or ball rolling.

40. The preparation method according to claim 39, characterized in that, The lubricant used in the tableting method includes high-purity graphite, and the amount of high-purity graphite used is 0.1~3wt%.

41. The preparation method according to claim 39, characterized in that, The post-compression treatment also includes calcination at 200~800℃ for 1~20h in an oxygen-containing atmosphere.

42. The preparation method according to claim 39, characterized in that, The catalyst after tableting is cylindrical, with a diameter of 2-10 mm and a height of 2-10 mm.

43. The preparation method according to claim 39, characterized in that, The binders used in both the extrusion method and the ball rolling method include silica sol, which is any one of sodium silica sol, ammonia silica sol, acid silica sol or aluminosilicate sol, and the amount of silica sol used is 1~10wt%.

44. The preparation method according to claim 39, characterized in that, Both the extrusion and rolling processes involve heating at 100-200℃ for 5-100 hours, followed by calcination at 200-800℃ for 1-20 hours in an oxygen-containing atmosphere.

45. The preparation method according to claim 39, characterized in that, The catalyst processed by the extrusion method is in the form of strips, with a diameter of 2-10 mm and a length of 2-10 mm.

46. ​​The preparation method according to claim 39, characterized in that, The catalyst treated by the rolling ball method is a sphere with a diameter of 2-8 mm.

47. The use of a dehydrogenation catalyst prepared by the method according to any one of claims 1-46, characterized in that, The dehydrogenation catalyst is used in the dehydrogenation reaction of diols to prepare lactones.

48. The use according to claim 47, characterized in that, The diols include any one or a combination of at least two of 1,3-propanediol, 1,4-butanediol, 1,4-pentanediol, 1,5-pentanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, or diethylene glycol and their derivatives.

49. The use according to claim 48, characterized in that, The diol is any one or a combination of at least two of 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, or diethylene glycol and their derivatives.

50. The use according to claim 48, characterized in that, In the derivative, at least one hydrogen atom bonded to a carbon atom is substituted by an alkyl group, an ether bond, a hydroxyl group, a carbonyl group, a carboxyl group, an ester group, an amino group, an imino group, a nitro group, a nitroso group, a cyano group, an amide group, or an aryl group.

51. The use according to claim 47, characterized in that, The raw material for the dehydrogenation reaction is a diol, and the process of the dehydrogenation reaction is as follows: the diol is mixed with hydrogen and vaporized, and then dehydrogenated and cyclized to generate the corresponding lactone.

52. The use according to claim 47, characterized in that, The dehydrogenation reaction is carried out at a temperature of 180~350℃.

53. The use according to claim 47, characterized in that, The mass hourly space velocity (MSV) of the dehydrogenation reaction is 0.1–10 h⁻¹. -1 .

54. The use according to claim 47, characterized in that, The dehydrogenation reaction is a hydrogen-induced reaction, with a hydrogen-to-alcohol molar ratio of (1~30):

1.

55. The use according to claim 47, characterized in that, The pressure of the dehydrogenation reaction is 0.01~1.0 MPaG.

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