Process for the oxidation of a double bond compound to produce an ortho-diol

Abstract

The application discloses a method for preparing o-diol by oxidizing a double bond compound, which comprises the following steps: contacting the double bond compound, an oxidant and a solvent in the presence of a catalyst containing a titanium-silicon molecular sieve and a cation exchange resin to obtain a product containing o-diol, wherein the cation exchange resin has sulfonic acid groups and carboxyl groups as exchangeable groups, and the cation exchange resin is exchanged by acid before use and is used in a hydrogen type. The method has the characteristics of mild reaction condition, simple operation process, high raw material conversion rate, high o-diol selectivity and high effective utilization rate of hydrogen peroxide.

Description

Technical Field

[0001] This invention relates to a method for preparing vicinal diols by oxidation of double-bonded compounds, and more particularly to a method for preparing vicinal diols by oxidation of double-bonded compounds in the presence of a titanium-silicon molecular sieve catalyst. Background Technology

[0002] vicinal glycols are hydrocarbon organic compounds in which hydroxyl groups are present on two adjacent carbon atoms. Common vicinal glycols include 1,2-ethylene glycol (hereinafter referred to as ethylene glycol), 1,2-propanediol (hereinafter referred to as propylene glycol), 1,2-butanediol (hereinafter referred to as butanediol), and 1,2-hexanediol (hereinafter referred to as hexanediol). Vicinal glycols have important applications. For example, ethylene glycol can be used as a solvent, antifreeze, and in the synthesis of polyester; propylene glycol can be used to synthesize unsaturated polyester resins and as an antifreeze and moisturizer; and hexanediol can be used in the production of high-end cosmetics. Vicinal glycols have broad market applications and large production volumes. For example, in 2018, the global production capacity of propylene glycol reached 1.8 million tons per year.

[0003] The main production method for vicinal glycols involves the hydrolysis of upstream epoxides under specific conditions. For example, ethylene oxide hydrolyzes to yield ethylene glycol, propylene oxide hydrolyzes to yield propylene glycol, and hexane oxide hydrolyzes to yield hexanediol. Additionally, propylene glycol can also be obtained through a dimethyl carbonate / propylene glycol co-production method. The epoxide hydrolysis method requires the prior preparation of the epoxide compound, increasing process complexity, reducing raw material utilization, and causing waste emissions, directly leading to increased costs. The co-production method also requires the prior production of the epoxide compound; furthermore, the price of co-produced products is always subject to market fluctuations.

[0004] US10214471 and US20180354878A1 disclose a method for reacting propylene and hydrogen peroxide in a reactor to obtain propylene glycol under the action of a heteropolyacid and a phase transfer catalyst. In this method, the heteropolyacid reacts with hydrogen peroxide in an aqueous phase to form a peroxide heteropolyacid salt, which is then reacted with the peroxide heteropolyacid salt to form a soluble salt in the organic phase via a phase transfer catalyst. In this method, an alkylated aromatic organic solvent with 8-12 carbon atoms increases the proportion of the heteropolyacid salt in the organic phase to complete the oxidation of propylene to propylene oxide. The heteropolyacid dissolves in water and continues to react with hydrogen peroxide; the resulting propylene oxide can enter the aqueous phase. Since the pH of the aqueous phase is maintained in the range of 1-3.5, the propylene oxide is hydrolyzed under the action of the acid in the aqueous phase to obtain propylene glycol. This method essentially only involves the two-step reaction of propylene epoxidation to propylene oxide and the hydrolysis of propylene oxide under acid to obtain propylene glycol, all carried out in a single reactor. The reaction requires a large amount of solvent and has a complex catalyst system, making the operation difficult.

[0005] EP1527057A1 discloses a method for the continuous preparation of propylene glycol. This method involves reacting propylene with hydrogen peroxide to produce propylene oxide, simultaneously generating propylene glycol as a byproduct. The generated propylene oxide is then reacted at 180-220°C and 15-25 bar to produce propylene glycol, which is then separated. This method is a physical integration of two steps: epoxidation and hydrolysis, and therefore cannot avoid the problems of low reaction efficiency and harsh hydrolysis conditions.

[0006] WO2019029808A1 discloses a method for preparing terminal 1,2-alkanediols with 5-12 carbon atoms, which involves reacting the corresponding terminal olefin with formic acid and hydrogen peroxide to obtain monoformate or diformate, and then decomposing them under the action of a decarbonization catalyst to obtain the corresponding diol and carbon monoxide.

[0007] CN103570493A discloses a method for synthesizing 1,2-vicinal diol via phase transfer catalytic oxidation using a supported heteropolyacid. The method involves mixing and reacting an acid, a terminal alkene, hydrogen peroxide, and a heteropolyacid phase transfer catalyst, followed by separation to obtain an epoxidized mixture. An alkaline solution is then added to maintain the pH at 10-12, and the mixture is further extracted by esterification and subjected to vacuum distillation to obtain the vicinal diol. This method has a long operational process and low product yield.

[0008] CN107879893A discloses a method for preparing vicinal diols via catalytic oxidation. The method involves preparing vicinal diols through the action of an olefin, an oxidant, and a bifunctional catalyst. The bifunctional catalyst contains silica-alumina molecular sieves, alumina, and titanium-silicon molecular sieves. This method uses an aluminum-containing catalyst, resulting in low utilization of hydrogen peroxide.

[0009] CN102452899A discloses a method for producing propylene glycol from propylene, which involves an epoxidation ring-opening hydration reaction of a titanium-silicon molecular sieve composite catalyst, propylene, and hydrogen peroxide to prepare propylene glycol. The titanium-silicon molecular sieve composite catalyst includes a titanium-silicon molecular sieve, an acidic molecular sieve, and a resin. However, this method has low hydrogen peroxide utilization.

[0010] CN104447204A discloses a method for preparing diols, which uses titanium-silicon molecular sieves supported on rare earth oxides as catalysts to promote the reaction of olefins and oxidants to produce diols. However, this method has low hydrogen peroxide utilization. Summary of the Invention

[0011] The purpose of this invention is to provide a method for the direct oxidation of olefins to prepare vicinal diols that is simple in process and has a high raw material utilization rate. This method has the characteristics of mild reaction conditions, simple operation process, high raw material conversion rate, high vicinal diol selectivity, and high hydrogen peroxide utilization rate.

[0012] To achieve the above objectives, the present invention provides a method for preparing vicinal diols by oxidation of double-bonded compounds. The method includes contacting a double-bonded compound, an oxidant, and a solvent in the presence of a catalyst containing a titanium silicate molecular sieve and a cation exchange resin to obtain a product containing vicinal diols. The cation exchange resin has sulfonic acid groups and carboxyl groups as exchangeable groups, and the cation exchange resin is acid-exchanged and used in its hydrogen form before use.

[0013] The double-bonded compound is a mono- or polyolefin with C2-C30, preferably C2-C18, and more preferably C3-C8.

[0014] The oxidant is selected from at least one of inorganic peroxides, organic peroxides, and ozone.

[0015] The inorganic peroxide is selected from at least one of hydrogen peroxide, urea peroxide, potassium persulfate, potassium persulfate, sodium percarbonate, percarbonamide, and sodium perborate; preferably, the organic peroxide is selected from at least one of tert-butyl hydroperoxide, cyclohexyl hydroperoxide, cumene peroxide, ethylbenzene hydroperoxide, benzoic acid peroxide, methyl ethyl ketone peroxide, tert-butyl perpentyl peroxide, isopropyl hydroperoxide, tert-amyl hydroperoxide, and di-tert-butyl peroxide. Preferably, the oxidant is hydrogen peroxide.

[0016] The contact reaction uses one or more of the following solvents: water, C2-C20 ethers, C2-C20 acids, C2-C30 esters and their derivatives. Preferably, the contact reaction uses water as the solvent.

[0017] The titanium-silicon molecular sieve is at least one of the following: MFI type titanium-silicon molecular sieve, MEL type titanium-silicon molecular sieve, BEA type titanium-silicon molecular sieve, MWW type titanium-silicon molecular sieve, MOR type titanium-silicon molecular sieve, TON type titanium-silicon molecular sieve, TUN type titanium-silicon molecular sieve, and hexagonal titanium-silicon molecular sieve; preferably, the titanium-silicon molecular sieve is an MFI type titanium-silicon molecular sieve; more preferably, the titanium-silicon molecular sieve is an MFI type titanium-silicon molecular sieve with a multi-level porous structure or a hollow crystal structure.

[0018] The cation exchange resin has sulfonic acid groups and carboxyl groups as exchangeable groups; preferably, the sulfonic acid groups account for more than 60% of all exchangeable groups. The cation exchange resin undergoes acid exchange before use and is used in its hydrogen form. The total exchange capacity of the cation exchange resin is 3-11 mmol / g, preferably 3.2-5 mmol / g.

[0019] In the method, the weight ratio of the titanium-silicon molecular sieve to the oxidant is (0.01-10):1. In the catalyst containing the titanium-silicon molecular sieve and cation exchange resin, the weight ratio of the cation exchange resin to the titanium-silicon molecular sieve is (0.1-5):1. The molar ratio of the oxidant to the olefin is (0.1-20):1. The molar ratio of the oxidant to the solvent is 1:(3-200). The reaction conditions are: reaction temperature of 5℃-100℃, reaction pressure of atmospheric pressure to 5MPa, and reaction time of 1min-24h.

[0020] The present invention provides a method for preparing vicinal diols by oxidizing double-bonded compounds. This method involves reacting an olefin, an oxidant, and a solvent in a single reactor under the catalytic action of a catalyst containing a titanium-silicon molecular sieve and a cation exchange resin to generate a product containing a vicinal diol. Compared with existing methods, this method eliminates the need for prior preparation of epoxide compounds, simplifies the operation, and utilizes mild reaction conditions. It also features high raw material conversion, high selectivity for vicinal diols, high utilization rate of hydrogen peroxide, and a safer and more efficient process, making it suitable for large-scale industrial production. Detailed Implementation

[0021] This invention provides a method for preparing vicinal diols by oxidation of double-bonded compounds. The method includes contacting a double-bonded compound, an oxidant, and a solvent in the presence of a catalyst containing a titanium silicate molecular sieve and a cation exchange resin to obtain a product containing vicinal diols. The cation exchange resin has sulfonic acid groups and carboxyl groups as exchangeable groups, and the cation exchange resin is acid-exchanged and used in its hydrogen form before use.

[0022] In the method provided by this invention, no restrictions are placed on the double-bonded compound raw materials. The olefin can be a mono-olefin or a poly-olefin. The olefin can be an aliphatic hydrocarbon, an alicyclic hydrocarbon, or an aromatic hydrocarbon, and may contain substituents such as alkyl, aryl, ester, nitro, hydroxyl, carboxyl, aldehyde, ketone, cyano, ether, amino, imino, or halogen substituents. It may contain oxygen, nitrogen, sulfur, phosphorus, or halogen heteroatoms. Preferably, the olefin is a C2-C30 mono-olefin or poly-olefin, more preferably a C2-C18 olefin, and more preferably a C3-C8 mono-olefin or poly-olefin. For example, the olefins may be ethylene, vinyl chloride, propylene, chloropropylene, acrylonitrile, acrylic acid, acrolein, allyl alcohol, butenoic acid, isobutene, 1-butene, 2-butene, butadiene, 1-pentene, cyclopentene, 1,4-pentadiene, cyclopentadiene, isoprene, 1-hexene, cyclohexene, 1-heptene, 1-octene, cyclooctene, 1-decene, cyclododecene, styrene, styrene, oleic acid, methyl oleate, castor oil acid, methyl ricinoleate, etc.

[0023] The olefins can be single-component olefins, mixed-component olefins, or mixed olefin feedstocks with inert components such as nitrogen, argon, helium, neon, air, oxygen, hydrogen, methane, ethane, propane, and butane. In the mixed olefin feedstock, the molar content of the olefins is preferably greater than 20%, more preferably greater than 50%, further preferably greater than 70%, and most preferably greater than 90%. For safety reasons, the oxygen and hydrogen content in the mixed olefin feedstock is controlled; preferably, the molar content of oxygen and the molar content of hydrogen are each less than 5%, preferably less than 2%, and more preferably less than 1%.

[0024] According to the present invention, the molar ratio of the oxidant to the olefin is (0.1-20):1, preferably (0.5-10):1, and more preferably (0.8-5):1.

[0025] According to the method of the present invention, the oxidant is at least one selected from inorganic peroxides, organic peroxides, and ozone. The inorganic peroxide is at least one selected from hydrogen peroxide, urea peroxide, potassium persulfate, potassium persulfate, sodium percarbonate, percarbonamide, and sodium perborate; the organic peroxide is at least one selected from tert-butyl hydroperoxide, cyclohexyl hydroperoxide, cumene peroxide, ethylbenzene hydroperoxide, benzoic acid peroxide, methyl ethyl ketone peroxide, tert-butyl perpentyl peroxide, isopropyl hydroperoxide, tert-amyl hydroperoxide, and di-tert-butyl peroxide. Hydrogen peroxide is a preferred oxidant.

[0026] Hydrogen peroxide is used in the form of hydrogen peroxide solution in this invention. This invention does not have specific requirements regarding the mass concentration of the hydrogen peroxide solution; preferably, the hydrogen peroxide solution is a solution with a hydrogen peroxide mass concentration of 2%-70%, more preferably 10%-50%, and even more preferably 20%-45%.

[0027] In this invention, the solvent can be selected from one or more of water, C2-C20 ethers, C2-C20 acids, C2-C30 esters, and their derivatives. For example, the solvent can be organic solvents such as dimethyl ether, diethyl ether, methyl tert-butyl ether, methyl cyclohexyl ether, anisole, acetic acid, propionic acid, butyric acid, malonic acid, octanoic acid, nonanoic acid, methyl formate, ethyl acetate, ethyl formate, butyl acetate, isopropyl acetate, cyclohexyl acetate, methyl oleate, ethyl oleate, and methyl castor oil.

[0028] Considering that adding organic solvents necessitates additional solvent separation, purification, and recovery units, leading to increased process complexity and energy consumption, from the perspective of optimizing the reaction process, reducing energy consumption, minimizing waste emissions, and improving the economics of the equipment, it is preferable to conduct the contact reaction using only water as the solvent instead of the aforementioned organic solvents. It is understood that the heterogeneous mass transfer resistance present during the reaction can be mitigated by existing technologies such as selecting a suitable reactor, adding internal components, and adjusting process parameters, which will not be elaborated upon here.

[0029] The method provided by this invention is carried out in the presence of a catalyst containing a titanium-silicon molecular sieve and a cation exchange resin. The titanium species in the framework of the titanium-silicon molecular sieve exhibit excellent properties in activating hydrogen peroxide and catalyzing the oxidation of organic molecules. In this invention, the titanium-silicon molecular sieve is a common type, such as MFI-type (e.g., TS-1), MEL-type (e.g., TS-2), BEA-type (e.g., Ti-β), MWW-type (e.g., Ti-MCM-22), MOR-type (e.g., Ti-MOR), TUN-type (e.g., Ti-TUN), hexagonal titanium-silicon molecular sieves (e.g., Ti-MCM-41, Ti-SBA-15), and other structures (e.g., Ti-ZSM-48). Preferably, the titanium-silicon molecular sieve is selected from at least one of MFI-type titanium-silicon molecular sieve, MEL-type titanium-silicon molecular sieve, and BEA-type titanium-silicon molecular sieve. More preferably, the titanium-silicon molecular sieve is an MFI-type titanium-silicon molecular sieve.

[0030] The MFI-type titanium-silicon molecular sieve described herein can be a TS-1 molecular sieve prepared by conventional methods such as hydrothermal synthesis or post-processing synthesis; it can be a titanium-silicon molecular sieve with a hierarchical porous structure (i.e., a pore distribution within the molecular sieve crystal in the range of 2-50 nm is obtained by fitting the molecular sieve pore distribution curve to the N2 adsorption-desorption curve using BJH fitting); it can be a hollow titanium-silicon molecular sieve (HTS) with an internal hollow structure (i.e., TEM characterization shows that there is one or more internal cavities within the molecular sieve crystal); or it can be a titanium-silicon molecular sieve with a plate-like, spherical, hexagonal prism shape, or an open surface. This invention does not impose specific limitations on these types. For better technical effects, the more preferred MFI-type titanium-silicon molecular sieve of this invention is a titanium-silicon molecular sieve with a hierarchical porous structure as described above and / or a hollow titanium-silicon molecular sieve (HTS) with an internal hollow structure.

[0031] The framework titanium in the titanium-silicon molecular sieve is the catalytic active center of the sieve. This invention does not have specific requirements for its titanium content; however, without violating objective laws, the higher the framework titanium content, the higher the catalytic activity. In this invention, the titanium-silicon molar ratio of the titanium-silicon molecular sieve can be (0.001-0.05):1, preferably (0.01-0.03):1.

[0032] In this invention, the titanium-silicon molecular sieve can be used directly as a catalyst from raw molecular sieve powder, or it can be shaped, for example, by pressing into tablets, rolling into microspheres or small spheres, extruding into strips, or spray drying into spherical catalysts before use; alternatively, the titanium-silicon molecular sieve can be added to the reaction of this invention simultaneously or sequentially with other catalysts, co-catalysts, and inert matrix supports without shaping. This invention does not impose any limitations on this. The catalyst containing titanium-silicon molecular sieve preferably has a titanium-silicon molecular sieve weight content of 20%-100%, more preferably 50%-100%, and even more preferably 80%-100%. Besides titanium-silicon molecular sieve as the main catalyst, it may also contain binders, co-catalysts, pore expanders, inert matrix supports, etc.

[0033] The inventors unexpectedly discovered that using titanium silicate molecular sieves in combination with specific cation exchange resins as catalysts can effectively promote the oxidation of double-bonded compounds to prepare vicinal diols. The cation exchange resins can be styrene-based resins (i.e., obtained by polymerizing styrene with the crosslinking agent divinylbenzene), acrylic resins (i.e., obtained by polymerizing acrylic acid with the crosslinking agent divinylbenzene), phenolic resins, epoxy resins, vinylpyridine resins, urea-formaldehyde resins, etc. Considering the requirements of economy and practicality, this invention preferably uses styrene-based or acrylic resins. Cation exchange resins are mature commercial products with numerous manufacturers and a wide variety available on the market.

[0034] Cation exchange resins achieve cation exchange by grafting anionic groups onto their backbone. According to the method of the present invention, the cation exchange resin has sulfonic acid groups and carboxyl groups as exchangeable groups, preferably with sulfonic acid groups accounting for more than 60% of all exchangeable groups, more preferably more than 85%, and even more preferably more than 95%.

[0035] The cation exchange capacity can be expressed as the total exchange capacity, which means the total number of chemical groups that can undergo ion exchange reactions per unit quantity (weight or volume) of resin. According to the method of the present invention, the total exchange capacity of the cation exchange resin (on a dry basis) is preferably 3-11 mmol / g, more preferably 3.2-5 mmol / g.

[0036] Cation exchange resins can be in the form of different metal cations, such as Na-form and K-form. By exchanging these cations with an acid solution of a certain concentration (such as sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid, acetic acid, etc.), their cations can be converted into H protons. According to the method of the present invention, the cation exchange resin is acid-exchanged before use and used in its H-form, with the percentage of metal cations and sulfonate ions being less than 50%, preferably less than 30%. This control parameter can be calculated by measuring the chemical composition of the cation exchange resin using the XRF method.

[0037] According to the method of the present invention, the weight ratio of the titanium-silicon molecular sieve to the oxidant is (0.01-10):1, preferably (0.05-5):1, and more preferably (0.1-2):1.

[0038] According to the method of the present invention, the titanium-silicon molecular sieve can be used as a catalyst after mechanically mixing with the cation exchange resin, or it can be used as a catalyst after molding the titanium-silicon molecular sieve and the cation exchange resin. The present invention does not impose any limitations. Preferably, the weight ratio of the cation exchange resin to the titanium-silicon molecular sieve is (0.1-5):1, more preferably (0.8-4):1, and even more preferably (1-2.5):1.

[0039] According to the method of the present invention, the preferred conditions for the contact are: a temperature of 5-100°C, preferably 20-80°C, and a pressure of atmospheric pressure to 5 MPa (gauge pressure). Within the preferred pressure range of the contact, the reaction system of the present invention can be a liquid-liquid-solid three-phase reaction, a gas-liquid-solid three-phase reaction, a liquid-solid two-phase reaction, or a gas-liquid-liquid-solid four-phase reaction.

[0040] According to the method of the present invention, the pressure can be the self-generated pressure formed by the reactants under reaction conditions, or it can be achieved by introducing a gaseous component that is inert to the reaction, such as, but not limited to, nitrogen, argon, helium, neon, air, oxygen, methane, ethane, propane, butane, etc., to maintain the reaction pressure and carry out the contact reaction process of the present invention under conditions that do not violate objective laws. For safety reasons, the oxygen content and hydrogen content are controlled, preferably with each molar content of oxygen and hydrogen being less than 5%, more preferably less than 2%, and more preferably less than 1%.

[0041] This invention can be carried out under intermittent or continuous conditions. From the perspective of reducing labor intensity, improving product quality, and considering the feasibility and safety of the technology, continuous conditions are preferred. The contact reaction, i.e., the reaction time, is preferably 1 min to 24 h, or the feed space velocity (based on oxides) is preferably 0.1 to 5 h. -1 .

[0042] The method provided by this invention can realize batch or continuous reactions in different types of reactors such as batch reactors, fixed-bed reactors, tubular reactors, fluidized-bed reactors, suspended-bed reactors, and microchannel reactors. Different reactor types are only to adapt to the corresponding purpose requirements and achieve better results in the one-step direct preparation of vicinal diols from olefins. At the same time, it is preferred to use appropriate catalysts in conjunction with the reactor. For example, fixed-bed reactors and tubular reactors use shaped catalysts, batch reactors use molecular sieve powder, and microchannel reactors use molecular sieve powder or immobilize the catalyst in the microchannels to achieve relatively better reaction results. All of these should be considered as part of this invention.

[0043] The method provided by this invention mainly generates vicinal diols, mono-vicinal diols (i.e., condensation etherification products of 2 vicinal diol molecules), di-vicinal diols (i.e., condensation etherification products of 3 vicinal diol molecules), aldehydes generated from the double bond cleavage of the starting olefin, and acids obtained from further oxidation of the aldehydes. The method further includes a step of separating the reaction products. For example, but not limited to, unreacted olefins and generated aldehydes can be separated by distillation, while the generated vicinal diols, mono-vicinal diols, and di-vicinal diols can be separated under reduced pressure or by extraction. Through the product separation steps described above, the overall separation energy consumption is low.

[0044] In the method of the present invention, the separation of the catalyst from the reaction system can be achieved in a variety of ways. For example, but not limited to, when using raw powdered titanium silicate molecular sieve as catalyst, the product separation and catalyst recycling can be achieved by sedimentation, filtration, centrifugation, evaporation, membrane separation, etc. Alternatively, the catalyst can be shaped and loaded into a fixed-bed reactor, and the catalyst can be recovered after the reaction is completed. Various methods for the separation and recovery of catalysts are involved in the existing literature, and will not be described in detail here.

[0045] The present invention will be further illustrated by the following examples, but these examples do not limit the scope of the invention.

[0046] The method for preparing the MFI-structured TS-1 molecular sieve used in the examples is as follows (referring to the method in Zeolites, 1992, 12(8), 943-50): approximately 3 / 4 of a tetrapropylammonium hydroxide (TPAOH, 20%, purchased from Aldrich, USA) solution was added to a tetraethyl orthosilicate (TEOS) solution to obtain a liquid mixture with a pH of approximately 13. Then, under vigorous stirring, the required amount of tetrabutyl titanate [Ti(OBu)4] was added dropwise to the obtained liquid mixture. A solution of anhydrous isopropanol was stirred for 15 minutes to obtain a clear liquid. The remaining TPAOH was then slowly added to the clear liquid, and the mixture was stirred at 348-353 K for approximately 3 hours to obtain a sol with a chemical composition of 0.03TiO2:SiO2:0.36TPA:35H2O. This sol was then crystallized at 443 K for 3 days. The resulting solid was filtered, washed with distilled water, dried at 373 K for 5 hours, and then calcined at 823 K for 10 hours to obtain the molecular sieve sample. The composition included 42 g of TEOS, 73 g of TPAOH, 2 g of Ti(OBu)4, 10 g of anhydrous isopropanol, and 68 g of water. The Ti:Si molar ratio in the TS-1 molecular sieve was 0.03:1.

[0047] Preparation of MFI structure hierarchical TS-1 used in the examples (refer to CN112898237A preparation comparative example 2): (1) Tetraethyl orthosilicate, tetrabutyl titanate, tetrapropylammonium hydroxide and water were mixed and treated at 30°C for 12 h to obtain a product with a molar composition of SiO2:TiO2:tetrapropylammonium hydroxide:water = 1:0.03:0.13:50; (2) The product of step (1) was treated at 90°C for 12 h; (3) The product of step (2) (calculated as SiO2) and silanizing agent were added to N-phenyl-3-aminopropyltrimethoxysilanizing agent at a molar ratio of 1:0.1 and treated at 170°C for 48 h; (4) The product obtained in step (3) was filtered and washed, and the filter cake was dried at 90°C for 12 h and calcined at 550°C for 6 h to obtain hierarchical TS-1 with silanizing agent pore expansion. In the hierarchical porous TS-1, the Ti:Si molar ratio is 0.03:1. Characterization by N2 adsorption-desorption and BJH pore distribution fitting revealed the presence of significant mesopores in the 5-30 nm range, with mesopore volumes greater than 0.7 cm³. 3 / g.

[0048] The hollow titanium-silicon molecular sieve HTS with MFI structure used in the examples was prepared according to the method described in Example 1 of Chinese Patent CN1301599A. In the HTS molecular sieve, the Ti:Si molar ratio is 0.03:1. TEM characterization shows that there is an obvious hollow structure inside the molecular sieve crystal.

[0049] Unless otherwise specified, all raw materials used in the examples are chemically pure reagents.

[0050] The reaction products were analyzed by gas chromatography, and the results were quantified using the external standard method. The chromatographic conditions were as follows: Agilent-6890 chromatograph, HP-5 capillary column, injection volume 0.5 μL, injection port temperature 280℃. Column temperature was maintained at 100℃ for 2 min, then increased to 250℃ at a rate of 15℃ / min and held for 15 min. An FID detector was used, with a detector temperature of 280℃.

[0051] The hydrogen peroxide content was measured using the indirect titration method with sodium thiosulfate.

[0052] The following indicators were mainly examined in each embodiment and comparative example:

[0053] Olefin conversion rate = (Number of moles of olefins consumed in the formation of each substance in the product) / (Number of moles of olefins in the feedstock) × 100%

[0054] Selectivity for vicinal diols = (Number of moles of vicinal diols in the product) / (Number of moles of olefins consumed in the formation of main and by-products) × 100%

[0055] Effective utilization rate of hydrogen peroxide = (moles of hydrogen peroxide consumed in the formation of organic matter in the product) / (moles of hydrogen peroxide in the raw materials before the reaction - moles of hydrogen peroxide in the product after the reaction) × 100%

[0056] Example 1

[0057] HTS molecular sieve, Amberlite IR-120 (H type) cation exchange resin, propylene, 30% (w / w) hydrogen peroxide solution, and the required amount of water were added to a reactor. The cation exchange resin had sulfonic acid groups comprising ≥97% of all exchangeable groups, a total exchange capacity ≥4.5 mmol / g, and a percentage of metal cations to sulfonic acid groups ≤20%. The molar ratio of titanium silicate molecular sieve to hydrogen peroxide (calculated as hydrogen peroxide) was 0.2:1, the weight ratio of cation exchange resin to titanium silicate molecular sieve was 1:1, the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to propylene was 2:1, and the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to water was 1:20. The mixture in the reactor was then reacted at 60℃ and 2 MPa for 3 h. After the reaction was completed, samples were taken for analysis, and the results are shown in Table 1.

[0058] Example 2

[0059] HTS molecular sieve, Amberlite IR-120 (H type) cation exchange resin, 1-butene, 30% (w / w) hydrogen peroxide solution, and the required amount of water were added to a reactor. The cation exchange resin had sulfonic acid groups comprising ≥97% of all exchangeable groups, a total exchange capacity ≥4.5 mmol / g, and a percentage of metal cations to sulfonic acid groups ≤20%. The molar ratio of titanium silicate molecular sieve to hydrogen peroxide (calculated as hydrogen peroxide) was 0.2:1, the weight ratio of cation exchange resin to titanium silicate molecular sieve was 1:1, the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to 1-butene was 2:1, and the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to water was 1:15. The mixture in the reactor was then reacted at 40℃ and 1 MPa for 3 h. After the reaction was completed, samples were taken for analysis, and the results are shown in Table 1.

[0060] Example 3

[0061] HTS molecular sieve, Amberlite IR-120 (H type) cation exchange resin, propylene, 30% (w / w) hydrogen peroxide solution, and the required amount of water were added to a reactor. The cation exchange resin had sulfonic acid groups comprising ≥97% of all exchangeable groups, a total exchange capacity ≥4.5 mmol / g, and a percentage of metal cations to sulfonic acid groups ≤20%. The molar ratio of titanium silicate molecular sieve to hydrogen peroxide (calculated as hydrogen peroxide) was 0.5:1, the weight ratio of cation exchange resin to titanium silicate molecular sieve was 1.5:1, the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to propylene was 3:1, and the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to water was 1:30. The mixture in the reactor was then reacted at 80℃ and 4 MPa for 2 hours. After the reaction was completed, samples were taken for analysis, and the results are shown in Table 1.

[0062] Example 4

[0063] HTS molecular sieve, Amberlite IR-120 (H type) cation exchange resin, propylene, 30% (w / w) hydrogen peroxide solution, and the required amount of water were added to a reactor. The cation exchange resin had sulfonic acid groups comprising ≥97% of all exchangeable groups, a total exchange capacity ≥4.5 mmol / g, and a percentage of metal cations to sulfonic acid groups ≤20%. The molar ratio of titanium silicate molecular sieve to hydrogen peroxide (calculated as hydrogen peroxide) was 0.5:1, the weight ratio of cation exchange resin to titanium silicate molecular sieve was 1.5:1, the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to propylene was 1.5:1, and the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to water was 1:20. The mixture in the reactor was then reacted at 70℃ and 2 MPa for 6 h. After the reaction was completed, samples were taken for analysis, and the results are shown in Table 1.

[0064] Example 5

[0065] HTS molecular sieve, Amberlite IR-120 (H type) cation exchange resin, 1-hexene, 30% (w / w) hydrogen peroxide solution, and the required amount of water were added to a reactor. The cation exchange resin had sulfonic acid groups comprising ≥97% of all exchangeable groups, a total exchange capacity ≥4.5 mmol / g, and a percentage of metal cations to sulfonic acid groups ≤20%. The molar ratio of titanium silicate molecular sieve to hydrogen peroxide (calculated as hydrogen peroxide) was 1:1, the weight ratio of cation exchange resin to titanium silicate molecular sieve was 2:1, the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to 1-hexene was 1.2:1, and the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to water was 1:20. The mixture in the reactor was then reacted at 50℃ and 0.5 MPa for 3 h. After the reaction was completed, samples were taken for analysis, and the results are shown in Table 1.

[0066] Example 6

[0067] HTS molecular sieve tablets were crushed to 20-40 mesh and then mixed with Dowex D001 (H type) cation exchange resin before being loaded into a fixed-bed reactor. The cation exchange resin had sulfonic acid groups comprising ≥96% of all exchangeable groups, a total exchange capacity ≥4.2 mmol / g, and a metal cation to sulfonic acid group ratio ≤25%. The weight ratio of the cation exchange resin to the titanium-silicon molecular sieve was 2.5:1. A 30% (w / w) hydrogen peroxide solution was mixed with the required amount of water and then separately pumped into the fixed-bed reactor with allyl chloride. The molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to allyl chloride was 1.5:1, and the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to water was 1:15. The mass hourly space velocity (MHV) relative to the catalyst (calculated as hydrogen peroxide) was 0.5 h⁻¹. The mixture was reacted at 30 °C and 0.2 MPa. After the reaction was complete, samples were taken for analysis. The results are shown in Table 1.

[0068] Example 7

[0069] HTS molecular sieve, Amberlite 732 (H type) cation exchange resin, propylene, 40% (w / w) hydrogen peroxide solution, and the required amount of methyl tert-butyl ether were added to a reactor. The cation exchange resin had sulfonic acid groups comprising ≥95% of all exchangeable groups, a total exchange capacity ≥4.0 mmol / g, and a percentage of metal cations to sulfonic acid groups ≤28%. The molar ratio of titanium silicate molecular sieve to hydrogen peroxide (calculated as hydrogen peroxide) was 0.4:1, the weight ratio of cation exchange resin to titanium silicate molecular sieve was 1.5:1, the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to propylene was 1.5:1, and the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to methyl tert-butyl ether was 1:10. The mixture in the reactor was then reacted at 50℃ and 1.5 MPa for 2 h. After the reaction was completed, samples were taken for analysis, and the results are shown in Table 1.

[0070] Example 8

[0071] TS-1 molecular sieve, Amberlite IR-120 (H type) cation exchange resin, propylene, 30% (w / w) hydrogen peroxide solution, and the required amount of water were added to a reactor. The cation exchange resin had sulfonic acid groups comprising ≥97% of all exchangeable groups, a total exchange capacity ≥4.5 mmol / g, and a percentage of metal cations to sulfonic acid groups ≤20%. The molar ratio of titanium silicate molecular sieve to hydrogen peroxide (calculated as hydrogen peroxide) was 0.2:1, the weight ratio of cation exchange resin to titanium silicate molecular sieve was 1:1, the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to propylene was 2:1, and the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to water was 1:20. The mixture in the reactor was then reacted at 60℃ and 2 MPa for 3 h. After the reaction was completed, samples were taken for analysis, and the results are shown in Table 1.

[0072] Example 9

[0073] Multi-level porous TS-1 molecular sieve, Amberlite IR-120 (H type) cation exchange resin, propylene, 30% (w / w) hydrogen peroxide solution, and the required amount of water were added to a reactor. The cation exchange resin had sulfonic acid groups comprising ≥97% of all exchangeable groups, a total exchange capacity ≥4.5 mmol / g, and a percentage of metal cations to sulfonic acid groups ≤20%. The molar ratio of titanium silicate molecular sieve to hydrogen peroxide (calculated as hydrogen peroxide) was 0.2:1, the weight ratio of cation exchange resin to titanium silicate molecular sieve was 1:1, the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to propylene was 2:1, and the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to water was 1:20. The mixture in the reactor was then reacted at 60℃ and 2MPa for 3 hours. After the reaction was completed, samples were taken for analysis, and the results are shown in Table 1.

[0074] Example 10

[0075] Multi-level porous TS-1 molecular sieve, Amberlite IR-120 (H type) cation exchange resin, propylene, 30% (w / w) hydrogen peroxide solution, and the required amount of water were added to a reactor. The cation exchange resin had sulfonic acid groups comprising ≥97% of all exchangeable groups, a total exchange capacity ≥4.5 mmol / g, and a percentage of metal cations to sulfonic acid groups ≤20%. The molar ratio of titanium silicate molecular sieve to hydrogen peroxide (calculated as hydrogen peroxide) was 0.5:1, the weight ratio of cation exchange resin to titanium silicate molecular sieve was 1.5:1, the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to propylene was 1.5:1, and the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to water was 1:10. The mixture in the reactor was then reacted at 40℃ and 2 MPa for 6 h. After the reaction was completed, samples were taken for analysis, and the results are shown in Table 1.

[0076] Example 11

[0077] Multi-level porous TS-1 molecular sieve, Amberlite IR-120 (H type) cation exchange resin, propylene, 30% (w / w) hydrogen peroxide solution, and the required amount of water were added to a reactor. The cation exchange resin had sulfonic acid groups comprising ≥97% of all exchangeable groups, a total exchange capacity ≥4.5 mmol / g, and a percentage of metal cations to sulfonic acid groups ≤20%. The molar ratio of titanium silicate molecular sieve to hydrogen peroxide (calculated as hydrogen peroxide) was 0.3:1, the weight ratio of cation exchange resin to titanium silicate molecular sieve was 2:1, the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to propylene was 1.8:1, and the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to water was 1:15. The mixture in the reactor was then reacted at 50℃ and 3MPa for 4 hours. After the reaction was completed, samples were taken for analysis, and the results are shown in Table 1.

[0078] Example 12

[0079] Multi-level porous TS-1 molecular sieve, Amberlite IR-120 (H type) cation exchange resin, propylene, 30% (w / w) hydrogen peroxide solution, and the required amount of water were added to a reactor. The cation exchange resin had sulfonic acid groups comprising ≥97% of all exchangeable groups, a total exchange capacity ≥4.5 mmol / g, and a percentage of metal cations to sulfonic acid groups ≤20%. The molar ratio of titanium silicate molecular sieve to hydrogen peroxide (calculated as hydrogen peroxide) was 0.15:1, the weight ratio of cation exchange resin to titanium silicate molecular sieve was 1:1, the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to propylene was 1.8:1, and the molar ratio of hydrogen peroxide (calculated as hydrogen peroxide) to water was 1:10. The mixture in the reactor was then reacted at 50℃ and 2 MPa for 4 h. After the reaction was completed, samples were taken for analysis, and the results are shown in Table 1.

[0080] Comparative Example 1

[0081] Unlike Example 8, no cation exchange resin was added. The analytical results are shown in Table 1.

[0082] Comparative Example 2

[0083] Unlike Example 9, no cation exchange resin was added. The analytical results are shown in Table 1.

[0084] Comparative Example 3

[0085] Unlike Example 1, no cation exchange resin was added. The analytical results are shown in Table 1.

[0086] Comparative Example 4

[0087] Unlike Example 1, HTS molecular sieve was not added. The analytical results are shown in Table 1.

[0088] Comparative Example 5

[0089] TS-1 molecular sieves loaded with cerium dioxide were prepared according to the method of Example 1 of Chinese Patent CN104447204A, and the reaction was evaluated according to the method of Example 1. In this case, the reaction process did not involve the addition of cation exchange resin, and CeO2 / TS-1 was used as the catalyst. The analytical results after the reaction were completed are shown in Table 1.

[0090] Table 1

[0091]

[0092] As can be seen from the results of Examples 1-12 and Comparative Examples 1-5 shown in Table 1, the method of the present invention for preparing vicinal diols is simple to operate, has mild reaction conditions, high olefin conversion and vicinal diol selectivity, high hydrogen peroxide utilization rate, and is safe and controllable, making it suitable for large-scale industrial production applications.

Claims

1. A method for preparing vicinal diols by oxidation of a double-bonded compound, the method comprising contacting the double-bonded compound and an oxidant in the presence of a catalyst containing a titanium silicate molecular sieve and a cation exchange resin at 20-80°C and using water as the solvent only to obtain a product containing vicinal diols, wherein the cation exchange resin has sulfonic acid groups and carboxyl groups as exchangeable groups, the total exchange capacity of the cation exchange resin is 3-11 mmol / g, the sulfonic acid groups account for more than 60% of all exchangeable groups, and the cation exchange resin is acid-exchanged and used in its hydrogen form before use. The percentage of metal cations and sulfonates is less than 50%; the titanium-silicon molecular sieve is an MFI type titanium-silicon molecular sieve with a hierarchical porous structure or a hollow crystal structure; in the catalyst containing titanium-silicon molecular sieve and cation exchange resin, the weight ratio of cation exchange resin to titanium-silicon molecular sieve is (1-2.5):1; the molar ratio of oxidant to water is 1:(3-200); the reaction conditions are: reaction pressure from atmospheric pressure to 5 MPa, and reaction time from 1 min to 24 h; the double bond compounds are propylene, chloropropylene, and 1-butene.

2. The method according to claim 1, wherein, The oxidant is selected from at least one of inorganic peroxides, organic peroxides, and ozone.

3. The method according to claim 2, wherein, The inorganic peroxide is selected from at least one of hydrogen peroxide, urea peroxide, potassium persulfate, potassium persulfate, sodium percarbonate, percarbonamide, and sodium perborate; the organic peroxide is selected from at least one of tert-butyl hydroperoxide, cyclohexyl hydroperoxide, cumene peroxide, ethylbenzene hydroperoxide, benzoic acid peroxide, methyl ethyl ketone peroxide, tert-butyl perpentyl peroxide, isopropyl hydroperoxide, tert-amyl hydroperoxide, and di-tert-butyl peroxide.

4. The method according to claim 1, wherein, The oxidant is hydrogen peroxide.

5. The method according to claim 1, wherein, The total exchange capacity of the cation exchange resin is 3.2-5 mmol / g.

6. The method according to claim 1, wherein, The weight ratio of the titanium-silicon molecular sieve to the oxidant is (0.01-10):

1.

7. The method according to claim 1, wherein, The molar ratio of the oxidant to the olefin is (0.1-20):1.

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