CN107963968B - Method for preparing phenyl acetate - Google Patents
Method for preparing phenyl acetate Download PDFInfo
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- CN107963968B CN107963968B CN201610917942.5A CN201610917942A CN107963968B CN 107963968 B CN107963968 B CN 107963968B CN 201610917942 A CN201610917942 A CN 201610917942A CN 107963968 B CN107963968 B CN 107963968B
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/89—Silicates, aluminosilicates or borosilicates of titanium, zirconium or hafnium
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/12—Oxidising
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/39—Preparation of carboxylic acid esters by oxidation of groups which are precursors for the acid moiety of the ester
- C07C67/42—Preparation of carboxylic acid esters by oxidation of groups which are precursors for the acid moiety of the ester by oxidation of secondary alcohols or ketones
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Abstract
The invention discloses a method for preparing phenyl acetate, which comprises the step of carrying out contact reaction on acetophenone, isopropanol and oxygen in the presence of a catalyst, wherein the catalyst is a titanium silicalite molecular sieve catalyst. The method has the advantages of simple process, easy control of production process, high conversion rate of acetophenone and good product selectivity. In addition, no additional solvent is needed in the reaction, the method is environment-friendly, the cost is low, and the method is very favorable for industrial production and application.
Description
Technical Field
The present invention relates to a process for producing phenyl acetate.
Background
Phenyl acetate is an important drug intermediate, and o-hydroxyacetophenone and p-hydroxyacetophenone obtained by conversion of phenyl acetate can be used for treating diseases such as acute and chronic icteric hepatitis and cholecystitis, wherein the o-hydroxyacetophenone is an important intermediate for synthesizing the antiarrhythmic drug, namely propafenone hydrochloride.
Currently, phenyl acetate is produced industrially mainly from sodium phenolate and acetic anhydride. Adding phenol into sodium hydroxide solution, stirring for dissolving to prepare sodium phenolate solution, adding acetic anhydride, reacting at 30-40 ℃, washing the obtained reaction product with water, dilute sodium hydroxide solution and water in sequence, drying by calcium chloride, and distilling to obtain the phenyl acetate product. The other operation method is that the phenol and the acetic anhydride are heated to boil together, reflux is carried out, water washing, alkali washing and water washing are carried out in sequence after cooling, after drying by anhydrous sodium sulfate, the fraction at 195 ℃ of 190-. It can be seen that any operation method has the problems of complex operation, multiple product treatment steps, relatively harsh reaction conditions, environmental pollution caused by acid and alkali adopted in the reaction process, and the like.
Disclosure of Invention
The invention aims to provide a method for preparing phenyl acetate, which has simple process, does not need additional solvent, and has higher conversion rate of raw materials and selectivity of products.
In order to achieve the above object, the present invention provides a method for preparing phenyl acetate, which comprises subjecting acetophenone, isopropanol and oxygen to a contact reaction in the presence of a catalyst, wherein the catalyst is a titanium silicalite catalyst.
Preferably, the molar ratio of acetophenone, oxygen and isopropanol is (0.01-10): (2-50): 1, preferably (0.05-0.5): (5-20): 1.
preferably, the method further comprises: the reaction is carried out in the presence of hydrogen peroxide, and the molar ratio of the hydrogen peroxide to the acetophenone is (0.0001-0.1): 1, preferably (0.0005-0.05): 1.
preferably, the method further comprises: firstly, mixing acetophenone, isopropanol and oxygen with inorganic acid containing halogen to obtain mixed materials, and then carrying out contact reaction on the mixed materials in the presence of the catalyst, wherein the molar ratio of the inorganic acid containing halogen to the acetophenone is (0.00001-0.1): 1, preferably (0.0001-0.01): 1.
preferably, the inorganic acid containing halogen includes at least one of hydrochloric acid, hydrobromic acid, hydrofluoric acid and hydroiodic acid, preferably hydrochloric acid and/or hydrobromic acid, and the mixing is performed under the following conditions: the mixing temperature is 20-100 deg.C, the mixing pressure is 0-2MPa, and the mixing time is 0.1-5 h.
Preferably, the catalyst is a titanium silicalite molecular sieve catalyst subjected to activation treatment, and the activation treatment comprises the step of contacting the titanium silicalite molecular sieve with an aqueous solution containing acid and optional peroxide, wherein the molar ratio of the acid, the peroxide, water and the titanium silicalite molecular sieve is (0.02-15) calculated by silicon dioxide: (0-10): (15-100): 1.
preferably, the acid is at least one selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, perchloric acid and C1-C5 carboxylic acids; the peroxide is at least one selected from hydrogen peroxide, tert-butyl hydroperoxide, cumyl peroxide and cyclohexyl hydroperoxide; the conditions of the activation treatment include: the titanium silicalite is contacted with an aqueous solution containing an acid and optionally a peroxide at a temperature of 0 to 90 ℃ for a time of 0.1 to 48 hours.
Preferably, the activation treatment comprises contacting the titanium silicalite molecular sieve with an aqueous solution containing nitric acid and peroxide, wherein the molar ratio of the nitric acid, the peroxide, the water and the titanium silicalite molecular sieve is (0.1-10): (0.01-5): (20-80): 1.
preferably, the activation treatment is carried out, so that the peak area of the absorption peak of the titanium silicalite molecular sieve subjected to the activation treatment in an ultraviolet-visible spectrum is reduced by more than 2%, preferably reduced by 2-30%, more preferably reduced by 2.5-15%, further preferably reduced by 3-10%, and still further preferably reduced by 3-6% based on the titanium silicalite molecular sieve; the pore volume of the titanium silicalite molecular sieve subjected to the activation treatment is reduced by more than 1%, preferably reduced by 1-20%, more preferably reduced by 1.5-10%, and further preferably reduced by 2-5%, and the pore volume is determined by a static nitrogen adsorption method.
Preferably, the titanium silicalite molecular sieve is at least one selected from the group consisting of an MFI-type titanium silicalite molecular sieve, an MEL-type titanium silicalite molecular sieve, a BEA-type titanium silicalite molecular sieve, an MWW-type titanium silicalite molecular sieve, an MOR-type titanium silicalite molecular sieve, a TUN-type titanium silicalite molecular sieve and a hexagonal-structure titanium silicalite molecular sieve.
Preferably, the titanium silicalite molecular sieve is a titanium silicalite molecular sieve TS-1, the surface silicon-titanium ratio of the titanium silicalite molecular sieve TS-1 is not lower than the bulk silicon-titanium ratio, the silicon-titanium ratio refers to the molar ratio of silicon oxide to titanium oxide, the surface silicon-titanium ratio is determined by adopting an X-ray photoelectron spectroscopy method, and the bulk silicon-titanium ratio is determined by adopting an X-ray fluorescence spectroscopy method; preferably, the ratio of the surface silicon-titanium ratio to the bulk silicon-titanium ratio is 1.2 or more; more preferably, the ratio of the surface silicon-titanium ratio to the bulk silicon-titanium ratio is 1.2-5; further preferably, the ratio of the surface silicon-titanium ratio to the bulk silicon-titanium ratio is 1.5-4.5.
Preferably, the titanium silicalite TS-1 is prepared by a method comprising the following steps: (A) dispersing an inorganic silicon source in an aqueous solution containing a titanium source and an alkali source template agent, and optionally supplementing water to obtain a dispersion liquid, wherein the ratio of the silicon source: a titanium source: alkali source template agent: the molar ratio of water is 100: (0.5-8): (5-30): (100-2000), the inorganic silicon source is SiO2The titanium source is calculated as TiO2The alkali source template agent is calculated by OH < - > or N; (B) standing the dispersion liquid obtained in the step (A) at 15-60 ℃ for 6-24 hours; (C) the dispersion obtained in the step (A) or the dispersion obtained in the step (B) is subjected to crystallization in a sealed reaction kettle in the order of stage (1), stage (2) and stage (3), the crystallization in the stage (1) is carried out at 80-150 ℃, preferably at 110-.
Preferably, the phases (1) and (3) satisfy one or both of the following conditions: condition 1: the crystallization temperature of the stage (1) is lower than the crystallization temperature of the stage (3), preferably the crystallization temperature of the stage (1) is 10-50 ℃ lower than the crystallization temperature of the stage (3), more preferably 20-40 ℃ lower; condition 2: the crystallization time of stage (1) is less than the crystallization time of stage (3), preferably the crystallization time of stage (1) is 5-24 hours, more preferably 6-12 hours shorter than the crystallization time of stage (3).
Preferably, the titanium source is an inorganic titanium salt selected from TiCl and/or an organic titanate4、Ti(SO4)2And TiOCl2At least one of the organic titanates of the general formula R7 4TiO4A compound of formula (I), R7Is an alkyl group having 2 to 4 carbon atoms; the alkali source template agent is at least one selected from quaternary ammonium base, aliphatic amine and aliphatic alcohol amine, preferably quaternary ammonium base, and more preferably tetrapropyl ammonium hydroxide; the inorganic silicon source is silica gel and/or silica sol.
Preferably, the weight ratio of the isopropanol to the catalyst is (1-100): 1, preferably (5-40): 1.
preferably, the reaction conditions are: the reaction temperature is 10-160 ℃, the reaction pressure is 0.1-5MPa, and the reaction time is 0.1-10 h.
According to the technical scheme, in the presence of oxygen, the acetophenone and isopropanol are directly used as raw materials to produce the phenyl acetate, the process is simple, the production process is easy to control, the conversion rate of the acetophenone is high, and the product selectivity is good. In addition, no additional solvent is needed in the reaction, the method is environment-friendly, the cost is low, and the method is very favorable for industrial production and application.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Detailed Description
The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
The invention provides a method for preparing phenyl acetate, which comprises the step of carrying out contact reaction on acetophenone, isopropanol and oxygen in the presence of a catalyst, wherein the catalyst is a titanium silicalite molecular sieve catalyst.
The inventor of the invention finds that in the long-term scientific research practice, in the presence of oxygen and a titanium silicalite molecular sieve catalyst, acetophenone and isopropanol are directly used as raw materials to produce phenyl acetate, no additional solvent is needed, the process is simple, the production efficiency is high, the conversion rate of the raw materials and the selectivity of the product are particularly and unexpectedly found to be high, presumably, the proportion of the isopropanol and the acetophenone is suitable for acetophenone oxidation in the reaction process, and oxygen in the reaction system also plays a certain role in improving the selectivity of the product.
In order to achieve the desired reaction effect, the molar ratio of acetophenone, oxygen and isopropanol may be (0.01-10): (2-50): 1, preferably (0.05-0.5): (5-20): 1.
in order to further improve the selectivity of the product and the conversion rate of the raw materials, it is preferable to introduce a small amount of hydrogen peroxide as a promoter into the reaction system. Accordingly, the method may further comprise: the reaction is carried out in the presence of hydrogen peroxide, which may be present in a molar ratio to acetophenone of (0.0001-0.1): 1, preferably (0.0005-0.05): 1.
in order to further improve the selectivity of the product and the conversion rate of the raw materials, the method can further comprise the following steps: firstly, mixing acetophenone, isopropanol and oxygen with inorganic acid containing halogen to obtain mixed materials, and then carrying out contact reaction on the mixed materials in the presence of the catalyst. When the amount of the halogen-containing inorganic acid added is small, the effects of improving the product selectivity and the raw material conversion rate can be achieved, for example, the molar ratio of the halogen-containing inorganic acid to the acetophenone can be (0.00001-0.1): 1, preferably (0.0001-0.01): 1. the kind of the inorganic acid containing halogen can be selected from a wide range, and preferably, the inorganic acid containing halogen includes at least one of hydrochloric acid, hydrobromic acid, hydrofluoric acid and hydroiodic acid, and more preferably, hydrochloric acid and/or hydrobromic acid. The mixing conditions may be: the mixing temperature is 20-100 ℃, preferably 20-80 ℃; the mixing pressure is 0-2MPa, preferably 0-0.05 MPa; the mixing time is 0.1-5 h.
In order to further improve the selectivity of the product and the conversion rate of the raw material, the catalyst can be an activated titanium silicalite catalyst. The activation treatment comprises the step of contacting the titanium silicalite molecular sieve with an aqueous solution containing acid and optional peroxide, wherein the molar ratio of the acid, the peroxide, the water and the titanium silicalite molecular sieve is (0.02-15): (0-10): (15-100): 1. the titanium silicalite molecular sieve after activation treatment has obviously improved catalytic performance, and can effectively improve the selectivity of the product phenyl acetate and the conversion rate of raw materials. The acid may be at least one selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, perchloric acid and C1-C5 carboxylic acids. The acid is generally present in the form of an aqueous solution, and the concentration of the aqueous solution is not particularly limited, and may be, for example, 1 to 60% by mass, preferably 5 to 30% by mass. The peroxide may be at least one selected from the group consisting of hydrogen peroxide, t-butyl hydroperoxide, cumene peroxide and cyclohexyl hydroperoxide. Preferably, the peroxide is hydrogen peroxide. The hydrogen peroxide may be hydrogen peroxide in various forms commonly used in the art.
For the purpose of improving the catalytic performance of the titanium silicalite molecular sieve to further improve the selectivity of the product and the conversion rate of the raw material, the conditions of the activation treatment can comprise: the titanium silicalite is contacted with an aqueous solution containing an acid and optionally a peroxide at a temperature of 0 to 90 ℃ for a time of 0.1 to 48 hours. In order to promote mass transfer in the catalyst activation treatment process, the aqueous solution can also comprise a solvent, and the weight ratio of the solvent to the titanium silicalite molecular sieve can be (5-30) to 1. The solvent may be at least one selected from the group consisting of C1-C6 alcohols, C3-C8 ketones, and C2-C6 nitriles. After the titanium silicalite molecular sieve is activated, the titanium silicalite molecular sieve can be recovered by adopting the conventional recovery steps of the molecular sieve in the field, for example, the steps of filtering and drying can be included, and the details are not repeated in the invention.
According to one embodiment of the present invention, the activation treatment preferably includes contacting a titanium silicalite with an aqueous solution containing nitric acid and peroxide, wherein the molar ratio of the nitric acid, the peroxide, the water and the titanium silicalite can be (0.1-10): (0.01-5): (20-80): 1.
the activation treatment can reduce the peak area of the absorption peak of the titanium silicalite molecular sieve subjected to the activation treatment between 230 and 310nm by more than 2%, preferably by 2-30%, more preferably by 2.5-15%, further preferably by 3-10%, and still further preferably by 3-6% in an ultraviolet-visible spectrum based on the titanium silicalite molecular sieve; the pore volume of the titanium silicalite molecular sieve subjected to the activation treatment is reduced by more than 1%, preferably reduced by 1-20%, more preferably reduced by 1.5-10%, and further preferably reduced by 2-5%, and the pore volume is determined by a static nitrogen adsorption method.
According to the present invention, the titanium silicalite molecular sieve is a common titanium silicalite molecular sieve, for example, the titanium silicalite molecular sieve can be an MFI type titanium silicalite molecular sieve (such as TS-1 molecular sieve), an MEL type titanium silicalite molecular sieve (such as TS-2 molecular sieve), a BEA type titanium silicalite molecular sieve (such as Ti-beta molecular sieve), an MWW type titanium silicalite molecular sieve (such as Ti-MCM-22 molecular sieve), an MOR type titanium silicalite molecular sieve (such as Ti-MOR molecular sieve), a TUN type titanium silicalite molecular sieve (such as Ti-TUN molecular sieve), a hexagonal structure titanium silicalite molecular sieve (such as Ti-MCM-41 molecular sieve, Ti-SBA-15 molecular sieve), and other structure titanium silicalite molecular sieves (such as Ti-ZSM-48 molecular sieve), etc. Preferably, the titanium silicalite molecular sieve is at least one selected from the group consisting of an MFI-type titanium silicalite molecular sieve, an MEL-type titanium silicalite molecular sieve and a BEA-type titanium silicalite molecular sieve. Further preferably, the titanium silicalite molecular sieve is an MFI-type titanium silicalite molecular sieve. The above titanium silicalite molecular sieves are commercially available or can be produced, and the methods for producing the titanium silicalite molecular sieves are well known to those skilled in the art, such as the methods described in Zeolite, 1992, Vol.12, page 943-950, and the present invention is not described herein in detail.
According to the invention, the titanium silicalite molecular sieve is preferably a titanium silicalite TS-1, and the surface silicon-titanium ratio of the titanium silicalite molecular sieve TS-1 is not lower than the bulk silicon-titanium ratio, so that the selectivity of the product phenyl acetate and the conversion rate of the raw material can be further improved. Preferably, the ratio of the surface silicon-titanium ratio to the bulk silicon-titanium ratio is 1.2 or more. More preferably, the ratio of the surface silicon to titanium ratio to the bulk silicon to titanium ratio is 1.2 to 5. Further preferably, the ratio of the surface silicon-titanium ratio to the bulk silicon-titanium ratio is 1.5-4.5. Still more preferably, the ratio of the surface silicon to titanium ratio to the bulk silicon to titanium ratio is 2 to 3. The silicon-titanium ratio refers to the molar ratio of silicon oxide to titanium oxide, the surface silicon-titanium ratio is determined by adopting an X-ray photoelectron spectroscopy, and the bulk silicon-titanium ratio is determined by adopting an X-ray fluorescence spectroscopy.
According to the method, the titanium silicalite TS-1 can be prepared by adopting a method comprising the following steps: (A) dispersing an inorganic silicon source in an aqueous solution containing a titanium source and an alkali source template agent, and optionally supplementing waterAnd obtaining a dispersion liquid, wherein the silicon source: a titanium source: alkali source template agent: the molar ratio of water is 100: (0.5-8): (5-30): (100-2000), the inorganic silicon source is SiO2The titanium source is calculated as TiO2The alkali source template is counted by OH < - > or N < - > (counted by N when the alkali source template contains nitrogen element; counted by OH < - > when the alkali source template does not contain nitrogen element); (B) optionally, standing the dispersion at 15-60 ℃ for 6-24 h; (C) and (3) sequentially carrying out stage (1), stage (2) and stage (3) crystallization on the dispersion liquid obtained in the step (A) or the dispersion liquid obtained in the step (B) in a sealed reaction kettle, wherein the stage (1) is crystallized for 6-72 hours at the temperature of 80-150 ℃, the stage (2) is cooled to the temperature of not higher than 70 ℃ and the retention time is at least 0.5 hour, and then the stage (3) is heated to the temperature of 120-200 ℃ for recrystallization for 6-96 hours.
The alkali source template can be various templates commonly used in the process of synthesizing the titanium silicalite molecular sieve, such as: the alkali source template agent can be one or more than two of quaternary ammonium base, aliphatic amine and aliphatic alcohol amine. The quaternary ammonium base can be various organic quaternary ammonium bases, and the aliphatic amine can be various NH3In which at least one hydrogen is substituted with an aliphatic hydrocarbon group (e.g., an alkyl group), which may be a variety of NH3Wherein at least one hydrogen is substituted with a hydroxyl-containing aliphatic group (e.g., an alkyl group).
Specifically, the alkali source template may be one or more selected from the group consisting of a quaternary ammonium base represented by formula I, an aliphatic amine represented by formula II, and an aliphatic alcohol amine represented by formula III.
In the formula I, R1、R2、R3And R4Each C1-C4 alkyl group including C1-C4 linear alkyl group and C3-C4 branched alkyl group, R1、R2、R3And R4Specific examples of (a) may include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, or tert-butyl.
R5(NH2)n(formula II)
In the formula II, n is an integer of 1 or 2. When n is 1, R5Is C1-C6 alkyl, including C1-C6 straight chain alkyl and C3-C6 branched chain alkyl, specific examples of which may include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, isopentyl, tert-pentyl or n-hexyl. When n is 2, R5Is C1-C6 alkylene, including C1-C6 linear alkylene and C3-C6 branched alkylene, specific examples of which may include, but are not limited to, methylene, ethylene, n-propylene, n-butylene, n-pentylene, or n-hexylene.
(HOR6)mNH(3-m)(formula III)
In the formula III, m is 1, 2 or 3. R6May be C1-C4 alkylene groups including C1-C4 linear alkylene groups and C3-C4 branched alkylene groups, specific examples of which may include, but are not limited to, methylene, ethylene, n-propylene and n-butylene groups.
Specific examples of the alkali-derived templating agent may include, but are not limited to: one or more of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide (including various isomers of tetrapropylammonium hydroxide such as tetra-n-propylammonium hydroxide and tetraisopropylammonium hydroxide), tetrabutylammonium hydroxide (including various isomers of tetrabutylammonium hydroxide such as tetra-n-butylammonium hydroxide and tetraisobutylammonium hydroxide), ethylamine, n-propylamine, n-butylamine, di-n-propylamine, butanediamine, hexanediamine, monoethanolamine, diethanolamine, and triethanolamine. Preferably, the alkali source template is one or more of tetraethylammonium hydroxide, tetrapropylammonium hydroxide and tetrabutylammonium hydroxide. More preferably, the alkali-source templating agent is tetrapropylammonium hydroxide.
The titanium source may be an inorganic titanium salt and/or an organic titanate, preferably an organic titanate. The inorganic titanium salt may be TiCl4、Ti(SO4)2Or TiOCl2One or more than two of the above; the organic titanate may be of the formula R7 4TiO4A compound of wherein R7Is C1-C6 alkyl, preferably C2-C4 alkyl.
The inorganic silicon source can be silica gel and/or silica sol, and silica gel is preferred. SiO in the silica sol2The content of (b) may be 10% by mass or more, preferably 15% by mass or more, and more preferably 20% by mass or more. In preparing the titanium silicalite molecular sieves according to this preferred embodiment, no source of organic silicon, such as organosilanes and organosiloxanes, is used.
In the dispersion, a silicon source: a titanium source: alkali source template agent: the molar ratio of water is preferably 100: (1-6): (8-25): (200-1500), more preferably 100: (2-5): (10-20): (400-1000).
The dispersion obtained in step (A) may be directly fed to step (C) for crystallization. Preferably, the dispersion obtained in step (A) is fed to step (B) and allowed to stand at a temperature of 15 to 60 ℃ for 6 to 24 hours. The step (B) between the step (A) and the step (C) can obviously improve the surface silicon-titanium ratio of the finally prepared titanium-silicon molecular sieve TS-1, so that the surface silicon-titanium ratio of the finally prepared titanium-silicon molecular sieve is not lower than the bulk silicon-titanium ratio, the catalytic performance of the finally prepared titanium-silicon molecular sieve can be obviously improved, the one-way service life of the finally prepared titanium-silicon molecular sieve is prolonged, and the effective utilization rate of an oxidant is improved. Generally, by placing step (B) between step (a) and step (C), the ratio of surface silicon to titanium to bulk silicon to titanium of the finally prepared titanium silicalite molecular sieve can be in the range of 1.2 to 5, preferably in the range of 1.5 to 4.5 (e.g., in the range of 2.5 to 4.5), more preferably in the range of 2 to 3. More preferably, the standing is carried out at a temperature of 20-50 deg.C, such as 25-45 deg.C.
In the step (B), the dispersion may be placed in a sealed container or may be placed in an open container and allowed to stand. Preferably, step (B) is carried out in a sealed vessel, so that introduction of external impurities into the dispersion during standing or volatilization loss of a part of the substance in the dispersion can be avoided.
After the standing in the step (B) is finished, the standing dispersion liquid can be directly sent into a reaction kettle for crystallization, or the standing dispersion liquid can be sent into the reaction kettle for crystallization after being redispersed, and preferably sent into the reaction kettle after being redispersed, so that the dispersion uniformity of the crystallized dispersion liquid can be further improved. The method of redispersion may be a conventional method such as one or a combination of two or more of stirring, sonication, and shaking. The duration of the redispersion is such that a homogeneous dispersion is formed from the dispersion on standing, and may generally be from 0.1 to 12 hours, for example from 0.5 to 2 hours. The redispersion can be carried out at ambient temperature, for example at a temperature of from 15 to 40 ℃.
In the step (C), the temperature increase rate and the temperature decrease rate for adjusting the temperature to each stage may be selected according to the type of the crystallization reactor specifically used, and are not particularly limited. In general, the rate of temperature increase to raise the temperature to the crystallization temperature of stage (1) may be from 0.1 to 20 deg.C/min, preferably from 0.1 to 10 deg.C/min, more preferably from 1 to 5 deg.C/min. The rate of temperature decrease from the stage (1) temperature to the stage (2) temperature may be from 1 to 50 deg.C/min, preferably from 2 to 20 deg.C/min, more preferably from 5 to 10 deg.C/min. The rate of temperature increase from the stage (2) temperature to the stage (3) crystallization temperature may be 1 to 50 ℃/min, preferably 2 to 40 ℃/min, more preferably 5 to 20 ℃/min.
In the step (C), the crystallization temperature in the stage (1) is preferably 110-. The crystallization time of stage (1) is preferably 6 to 24h, more preferably 6 to 8 h. The temperature of the stage (2) is preferably not higher than 50 ℃. The residence time of stage (2) is preferably at least 1h, more preferably from 1 to 5 h. The crystallization temperature of stage (3) is preferably 140-. The crystallization time of stage (3) is preferably 12-20 h.
In step (C), in a preferred embodiment, the crystallization temperature in stage (1) is lower than that in stage (3), so as to further improve the catalytic performance of the prepared titanium silicalite molecular sieve. Preferably, the crystallization temperature of stage (1) is 10-50 ℃ lower than the crystallization temperature of stage (3). More preferably, the crystallization temperature of stage (1) is 20-40 ℃ lower than the crystallization temperature of stage (3). In step (C), in another preferred embodiment, the crystallization time in stage (1) is shorter than that in stage (3), so as to further improve the catalytic performance of the finally prepared titanium silicalite molecular sieve. Preferably, the crystallization time of stage (1) is 5-24h shorter than the crystallization time of stage (3). More preferably, the crystallization time of stage (1) is 6-12h, such as 6-8h shorter than the crystallization time of stage (3). In step (C), these two preferred embodiments may be used alone or in combination, preferably in combination, that is, the crystallization temperature and crystallization time of stage (1) and stage (3) satisfy the requirements of these two preferred embodiments at the same time.
In step (C), in another preferred embodiment, the temperature of stage (2) is not higher than 50 ℃, and the residence time is at least 0.5h, such as 0.5-6h, so as to further improve the catalytic performance of the finally prepared titanium silicalite molecular sieve. Preferably, the residence time of stage (2) is at least 1h, such as 1-5 h. This preferred embodiment can be used separately from the two preferred embodiments described above, or in combination, preferably in combination, i.e. the crystallization temperature and crystallization time of stage (1) and stage (3) and the temperature and residence time of stage (2) simultaneously meet the requirements of the three preferred embodiments described above.
Conventional methods can be used to recover the titanium silicalite from the mixture crystallized in step (C). Specifically, after optionally filtering and washing the mixture obtained by crystallization in step (C), the solid matter may be dried and calcined to obtain the titanium silicalite molecular sieve. The drying and the firing may be performed under conventional conditions. Generally, the drying may be carried out at a temperature of from ambient temperature (e.g., 15 ℃) to 200 ℃. The drying may be carried out at ambient pressure (typically 1 atm), or under reduced pressure. The duration of the drying may be selected according to the temperature and pressure of the drying and the manner of the drying, and is not particularly limited. For example, when the drying is carried out at ambient pressure, the temperature is preferably 80 to 150 ℃, more preferably 100 ℃ to 120 ℃, and the duration of the drying is preferably 0.5 to 5 hours, more preferably 1 to 3 hours. The calcination may be carried out at a temperature of 300-800 ℃, preferably at a temperature of 500-700 ℃, more preferably at a temperature of 550-650 ℃, and even more preferably at a temperature of 550-600 ℃. The duration of the calcination may be selected according to the temperature at which the calcination is carried out, and may generally be 2 to 12 hours, preferably 2 to 5 hours. The calcination is preferably carried out in an air atmosphere.
In order to achieve the desired reaction effect, the weight ratio of the isopropanol to the catalyst can be (1-100): 1, preferably (5-40): 1.
according to the invention, the reaction conditions may be: the reaction temperature is 10-160 ℃, preferably 20-140 ℃, and more preferably 30-90 ℃; the reaction pressure is 0.1-5MPa, preferably 0.1-3MPa, and more preferably 0.5-1.5 MPa; the time is 0.1 to 10 hours, preferably 0.1 to 3 hours, and more preferably 0.5 to 3 hours.
The reaction according to the present invention may be carried out in a conventional catalytic reactor, and the present invention is not particularly limited, for example, the reaction according to the present invention may be carried out in a batch tank reactor such as a three-necked flask, or in a suitable other continuous reactor such as a fixed bed, a moving bed, a suspended bed, etc. When the reaction of the invention is carried out in a fixed bed reactor, the total liquid hourly space velocity can be 0.1-100h-1Preferably 1-10h-1。
It can be understood by those skilled in the art that, depending on the reactor used, the titanium silicalite catalyst of the present invention may be titanium silicalite raw powder, or may be a molded catalyst formed by mixing a titanium silicalite with a carrier. The separation of the product from the catalyst can be achieved in various ways, for example, when the original powdery titanium silicalite molecular sieve is used as the catalyst, the separation of the product and the recovery and reuse of the catalyst can be achieved by settling, filtering, centrifuging, evaporating, membrane separating, etc., or the catalyst can be molded and then loaded into a fixed bed reactor, and the catalyst is recovered after the reaction is finished.
The present invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.
In the following examples, the reagents used were all commercially available reagents, and the pressure was gauge pressure.
The composition of the reaction product is analyzed by gas chromatography, and the analysis result is quantified by a correction normalization method. Wherein, the chromatographic analysis conditions are as follows: agilent-6890 type chromatograph, HP-5 capillary chromatographic column, sample amount of 0.5 μ L, and sample inlet temperature of 280 deg.C. The column temperature was maintained at 100 ℃ for 2min, then ramped up to 200 ℃ at a rate of 15 ℃/min and maintained for 3 min. FID detector, detector temperature 300 ℃.
In each example:
the conversion rate of acetophenone is (the mole number of acetophenone in the raw material-the mole number of acetophenone in the product)/the mole number of acetophenone in the raw material is multiplied by 100%
Phenyl acetate selectivity ═ the number of moles of phenyl acetate in the product/(the number of moles of acetophenone in the starting material-the number of moles of acetophenone in the product). times.100%
Acetone selectivity ═ mole number of acetone in product/(mole number of isopropanol in starting material-mole number of isopropanol in product) × 100%
In the following examples, the pore volume and the ultraviolet absorption peak of the titanium silicalite molecular sieve before and after the activation treatment are respectively characterized by a static nitrogen adsorption method and a solid ultraviolet-visible diffuse reflectance spectroscopy method. Wherein the static nitrogen adsorption was carried out on a static nitrogen adsorption apparatus model ASAP 2405 from Micromeritics, measured according to ASTM D4222-98. And (3) adsorbing nitrogen in a liquid nitrogen cold trap, keeping the titanium silicalite molecular sieve sample at 393K under the vacuum degree of 1.3kPa for 4h for degassing, and adsorbing nitrogen at 77K. Solid ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis) analysis is carried out on a SHIMADZU UV-3100 type ultraviolet-visible spectrometer, measurement is carried out at normal temperature and normal pressure, and the scanning wavelength range is 190 nm-800 nm. And (3) performing a powder tabletting method, roasting the sample, taking a certain amount of sample, putting the sample into a mortar, grinding the sample to be less than 300 meshes, and tabletting to prepare the sample.
In the following examples including the steps of preparing a titanium silicalite molecular sieve, the silicon-titanium ratio refers to the molar ratio of silicon oxide to titanium oxide, the surface silicon-titanium ratio is measured by an X-ray photoelectron spectrometer, the instrument model PHI Quantera SXM (Scanning X-ray Microprobe), the monochromator is adopted, the Al anode target is selected, the energy resolution is 0.5eV, the sensitivity is 3M CPS, the incident angle is 45 degrees, and the vacuum degree of the analysis chamber is 6.7 × 10-8Pa; the bulk silicon titanium is compared with that of 32 of Nippon-King Kogyo Motor Co., Ltd71E X-ray fluorescence spectrometer, detecting spectral line intensity of each element with rhodium target, excitation voltage of 50kV and excitation current of 50mA, using scintillation counter and proportional counter, performing sample roasting treatment by powder tabletting method, taking a certain amount of sample, placing into mortar, and grinding<300 meshes, tabletting and sampling.
Example 1
The catalyst used in this example was titanium silicalite TS-1, prepared as described in Zeolite, 1992, Vol.12, pp 943-950, as follows.
At room temperature (20 ℃), 22.5g tetraethyl orthosilicate was mixed with 7.0g tetrapropylammonium hydroxide as a template, 59.8g distilled water was added, and after stirring and mixing, hydrolysis was performed at 60 ℃ for 1.0 hour under normal pressure to obtain a hydrolysis solution of tetraethyl orthosilicate. To the hydrolysis solution was slowly added a solution consisting of 1.1g tetrabutyl titanate and 5.0g anhydrous isopropanol with vigorous stirring, and the resulting mixture was stirred at 75 ℃ for 3h to give a clear and transparent colloid. Placing the colloid in a stainless steel sealed reaction kettle, and standing at a constant temperature of 170 ℃ for 36h to obtain a mixture of crystallized products. Filtering the obtained mixture, collecting the obtained solid matter, washing with water, drying at 110 ℃ for 60min, and then roasting at 500 ℃ for 6h to obtain the titanium silicalite TS-1 with the titanium oxide content of 2.8 wt%.
In a kettle type reactor, reacting acetophenone, isopropanol and the catalyst TS-1 molecular sieve according to the molar ratio of the acetophenone to the isopropanol of 0.01:1 and the weight ratio of the acetophenone to the catalyst of 50:1 in an oxygen atmosphere at the temperature of 100 ℃ and the pressure of 2MPa, wherein the molar ratio of the oxygen to the isopropanol is 2: 1; samples were taken at 0.1 hour from the reaction and analyzed, the results of which are shown in Table 1.
Example 2
In a kettle type reactor, reacting acetophenone, isopropanol and a catalyst TS-1 molecular sieve which is the same as the catalyst in example 1 according to the molar ratio of the acetophenone to the isopropanol of 1:1 and the weight ratio of the acetophenone to the catalyst of 1:1 in an oxygen atmosphere at the temperature of 140 ℃ and the pressure of 2.5MPa, wherein the molar ratio of oxygen to the isopropanol of 50: 1; samples were taken for 1 hour of reaction and analyzed, the results of which are shown in Table 1.
Example 3
In a kettle reactor, reacting acetophenone, isopropanol and a catalyst TS-1 molecular sieve which is the same as in example 1 according to the molar ratio of the acetophenone to the isopropanol of 0.5:1 and the weight ratio of the acetophenone to the catalyst of 20:1 in an oxygen atmosphere at the temperature of 90 ℃ and the pressure of 1.5MPa, wherein the molar ratio of oxygen to the isopropanol of 10: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 4
The titanium silicalite TS-1 used in this example was prepared by the following method:
tetrabutyl titanate is firstly dissolved in an alkali source template tetrapropyl ammonium hydroxide aqueous solution, then silica gel (purchased from Qingdao silica gel factory) is added to obtain a dispersion liquid, and in the dispersion liquid, a silicon source: a titanium source: alkali source template agent: the molar ratio of water is 100: 4: 12: 400, the silicon source is SiO2The titanium source is calculated as TiO2The alkali source template is counted as N. The dispersion was sealed with a sealing film in a beaker, and then allowed to stand at room temperature (25 ℃ C., the same applies hereinafter) for 24 hours, followed by stirring at 35 ℃ for 2 hours with magnetic stirring to redisperse the dispersion. Transferring the re-dispersed dispersion liquid into a sealed reaction kettle, carrying out first-stage crystallization for 6h at 140 ℃, then cooling the mixture to 30 ℃, carrying out second-stage retention for 2h, continuing to carry out third-stage crystallization for 12h at 170 ℃ in the sealed reaction kettle (wherein the heating rate from room temperature to the first-stage crystallization temperature is 2 ℃/min, the cooling rate from the first-stage crystallization temperature to the second-stage treatment temperature is 5 ℃/min, and the heating rate from the second-stage treatment temperature to the third-stage crystallization temperature is 10 ℃/min), taking out the obtained crystallized product, directly drying for 2h at 110 ℃, and then roasting for 3h at 550 ℃ to obtain the molecular sieve. In the titanium silicalite molecular sieve, the content of titanium oxide was 3.5 wt%, and the surface silicon-titanium ratio/bulk silicon-titanium ratio was 2.58 (in the titanium silicalite molecular sieve prepared in example 1, the surface silicon-titanium ratio/bulk silicon-titanium ratio was 1.05).
In a kettle type reactor, reacting acetophenone, isopropanol and the prepared catalyst TS-1 molecular sieve according to the molar ratio of the acetophenone to the isopropanol of 0.5:1 and the weight ratio of the acetophenone to the catalyst of 20:1 in an oxygen atmosphere at the temperature of 90 ℃ and the pressure of 1.5MPa, wherein the molar ratio of oxygen to the isopropanol is 10: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 5
In a kettle type reactor, reacting acetophenone, isopropanol and a catalyst hollow titanium silicalite molecular sieve HTS (purchased from Hunan Jian petrochemical Co., Ltd.) in an oxygen atmosphere at a molar ratio of the acetophenone to the isopropanol of 0.2:1 and a weight ratio of the acetophenone to the catalyst of 10:1 at a temperature of 90 ℃ and a pressure of 1.5MPa, wherein the molar ratio of the oxygen to the isopropanol is 6: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 6
Reacting acetophenone, isopropanol and a catalyst TS-1 molecular sieve which is the same as in example 4 in a molar ratio of 0.5:1 of acetophenone to isopropanol and a weight ratio of acetophenone to catalyst of 20:1 in a kettle reactor at a temperature of 90 ℃ and a pressure of 1.5MPa in an oxygen atmosphere and in the presence of a trace amount of hydrogen peroxide, wherein the molar ratio of oxygen to isopropanol is 10:1 and the molar ratio of hydrogen peroxide to acetophenone is 0.05: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 7
Reacting acetophenone, isopropanol and a catalyst hollow titanium silicalite molecular sieve HTS (purchased from the Henan Jian petrochemical Co., Ltd.) in a kettle type reactor according to a molar ratio of the acetophenone to the isopropanol of 0.2:1 and a weight ratio of the acetophenone to the catalyst of 10:1 under the conditions of a temperature of 90 ℃ and a pressure of 1.5MPa in an oxygen atmosphere and in the presence of trace hydrogen peroxide, wherein the molar ratio of the oxygen to the isopropanol is 6:1, and the molar ratio of the hydrogen peroxide to the acetophenone is 0.0005: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 8
Reacting acetophenone, isopropanol and a catalyst TS-1 molecular sieve which is the same as in example 4 in a molar ratio of 0.05:1 of acetophenone to isopropanol and a weight ratio of acetophenone to catalyst of 100:1 in a kettle reactor at a temperature of 160 ℃ and a pressure of 1.5MPa in an oxygen atmosphere and in the presence of a trace amount of hydrogen peroxide, wherein the molar ratio of oxygen to isopropanol is 4:1 and the molar ratio of hydrogen peroxide to acetophenone is 0.0001: 1; samples were taken for 3 hours of reaction and analyzed, the results of which are shown in Table 1.
Example 9
The Ti-beta molecular sieve used in the embodiment is prepared according to the method of embodiment 1 in Chinese patent CN 103395798A.
Reacting acetophenone, isopropanol and a catalyst Ti-beta molecular sieve in a kettle type reactor according to the molar ratio of the acetophenone to the isopropanol of 5:1 and the weight ratio of the acetophenone to the catalyst of 60:1 under the conditions of 10 ℃ and 1.5MPa in an oxygen atmosphere and in the presence of trace hydrogen peroxide, wherein the molar ratio of oxygen to the isopropanol is 25:1, and the molar ratio of the hydrogen peroxide to the acetophenone is 0.1: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 10
Reacting acetophenone, isopropanol, 25 mass% hydrochloric acid and a catalyst TS-1 molecular sieve which is the same as in example 4 in a molar ratio of acetophenone to isopropanol of 0.5:1, a molar ratio of hydrochloric acid (calculated as HCl) to acetophenone of 0.0001:1, a weight ratio of acetophenone to catalyst of 20:1 in a kettle reactor under an oxygen atmosphere and in the presence of a trace amount of hydrogen peroxide at a temperature of 90 ℃ and a pressure of 1.5MPa, wherein the molar ratio of oxygen to isopropanol is 10:1, and the molar ratio of hydrogen peroxide to acetophenone is 0.05: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 11
In a kettle reactor, acetophenone and isopropanol, 25 mass percent hydrofluoric acid and the same catalyst TS-1 molecular sieve as in example 4 are reacted according to the molar ratio of acetophenone to isopropanol of 0.1:1, the molar ratio of hydrofluoric acid (calculated as HF) to acetophenone of 0.005:1, the weight ratio of acetophenone to catalyst of 40:1, at a temperature of 90 ℃ and a pressure of 1.5MPa, in an oxygen atmosphere and in the presence of a trace amount of hydrogen peroxide, wherein the molar ratio of oxygen to isopropanol is 5:1, and the molar ratio of hydrogen peroxide to acetophenone is 0.01: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 12
Reacting acetophenone and isopropanol, 25 mass% hydroiodic acid and the same catalyst TS-1 molecular sieve as in example 4 in a molar ratio of acetophenone to isopropanol of 0.4:1, a molar ratio of hydroiodic acid (calculated as HI) to acetophenone of 0.001:1, a weight ratio of acetophenone to catalyst of 30:1 in a kettle reactor at a temperature of 60 ℃ and a pressure of 1.5MPa in an oxygen atmosphere in the presence of a trace amount of hydrogen peroxide, wherein the molar ratio of oxygen to isopropanol is 20:1 and the molar ratio of hydrogen peroxide to acetophenone is 0.005: 1; samples were taken for 3 hours of reaction and analyzed, the results of which are shown in Table 1.
Example 13
Reacting acetophenone and isopropanol, 25 mass% hydrochloric acid and the same catalyst TS-1 molecular sieve as in example 1 in a molar ratio of acetophenone to isopropanol of 0.02:1, a molar ratio of hydrochloric acid (as HCl) to acetophenone of 0.00001:1, a weight ratio of acetophenone to catalyst of 80:1 in an oxygen atmosphere and in the presence of a trace amount of hydrogen peroxide at a temperature of 90 ℃ and a pressure of 1.5MPa in a tank reactor, wherein the molar ratio of oxygen to isopropanol is 50:1, and the molar ratio of hydrogen peroxide to acetophenone is 0.0002: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 14
In a kettle reactor, acetophenone and isopropanol, 25 mass percent hydrochloric acid and the same catalyst TS-1 molecular sieve as in example 1 are reacted according to the molar ratio of acetophenone to isopropanol of 0.08:1, the molar ratio of hydrochloric acid (calculated as HCl) to acetophenone of 0.1:1 and the weight ratio of acetophenone to catalyst of 2:1 under the conditions of 90 ℃ and 1.5MPa in an oxygen atmosphere and in the presence of trace hydrogen peroxide, wherein the molar ratio of oxygen to isopropanol is 30:1, and the molar ratio of hydrogen peroxide to acetophenone is 0.08: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 15
The titanium silicalite TS-1 as in example 4 is added into a mixed aqueous solution containing hydrochloric acid and hydrogen peroxide, and is activated under stirring, the molar ratio of the hydrochloric acid (calculated as HCl) to the hydrogen peroxide to the water to the TS-1 molecular sieve (calculated as silicon dioxide) in the mixed aqueous solution is 5: 2: 60:1, the treatment temperature is 30 ℃, the treatment time is 20 hours, and then the activated TS-1 molecular sieve is obtained by recovery. Compared with the titanium silicalite TS-1 of the example 4, the titanium silicalite TS-1 after the activation treatment has the advantages that the peak area of the absorption peak between 230 and 310nm in the UV-Vis spectrum is reduced by 5.8 percent, and the pore volume determined by a static nitrogen adsorption method is reduced by 3.6 percent.
Reacting acetophenone, isopropanol, 25 mass% of hydrochloric acid and the activated TS-1 molecular sieve catalyst in a molar ratio of the acetophenone to the isopropanol of 0.5:1, a molar ratio of the hydrochloric acid (calculated as HCl) to the acetophenone of 0.0001:1 and a weight ratio of the acetophenone to the catalyst of 20:1 in a kettle reactor under the conditions of a temperature of 90 ℃ and a pressure of 1.5MPa in an oxygen atmosphere and in the presence of a trace amount of hydrogen peroxide, wherein the molar ratio of the oxygen to the isopropanol is 10:1 and the molar ratio of the hydrogen peroxide to the acetophenone is 0.05: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 16
Adding the titanium silicalite TS-1 same as the titanium silicalite TS-1 in the embodiment 4 into a mixed aqueous solution containing nitric acid and hydrogen peroxide, and activating the mixed aqueous solution under stirring to obtain nitric acid (HNO)3The molar ratio of hydrogen peroxide to water to the TS-1 molecular sieve (calculated by silicon dioxide) is 5: 2: 60:1, the treatment temperature is 30 ℃, the treatment time is 20 hours, and then the activated TS-1 molecular sieve is obtained by recovery. Compared with the titanium silicalite TS-1 of the example 4, the titanium silicalite TS-1 after the activation treatment has the advantages that the peak area of the absorption peak between 230 and 310nm in the UV-Vis spectrum is reduced by 5.3 percent, and the pore volume determined by a static nitrogen adsorption method is reduced by 4.8 percent.
Reacting acetophenone, isopropanol, 25 mass% of hydrochloric acid and the activated TS-1 molecular sieve catalyst in a molar ratio of the acetophenone to the isopropanol of 0.5:1, a molar ratio of the hydrochloric acid (calculated as HCl) to the acetophenone of 0.0001:1 and a weight ratio of the acetophenone to the catalyst of 20:1 in a kettle reactor under the conditions of a temperature of 90 ℃ and a pressure of 1.5MPa in an oxygen atmosphere and in the presence of a trace amount of hydrogen peroxide, wherein the molar ratio of the oxygen to the isopropanol is 10:1 and the molar ratio of the hydrogen peroxide to the acetophenone is 0.05: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 17
The same catalyst TS-1 molecular sieve as in example 1 was added to a mixed aqueous solution containing hydrochloric acid and hydrogen peroxide, and the mixture was activated with stirring at a molar ratio of hydrochloric acid (as HCl) to hydrogen peroxide to water to TS-1 molecular sieve (as silica) of 0.02: 10: 15: 1 at 30 ℃ for 20 hours, and then recovered to obtain an activated TS-2 molecular sieve. Compared with the titanium silicalite TS-1 of the example 1, the titanium silicalite TS-1 after the activation treatment has the advantages that the peak area of the absorption peak between 230 and 310nm in the UV-Vis spectrum is reduced by 7.0 percent, and the pore volume determined by a static nitrogen adsorption method is reduced by 4.4 percent.
Reacting acetophenone, isopropanol, 25 mass% of hydrochloric acid and the activated TS-1 molecular sieve catalyst in a kettle reactor at a molar ratio of acetophenone to isopropanol of 8:1, a molar ratio of hydrochloric acid (calculated as HCl) to acetophenone of 0.05:1 and a weight ratio of acetophenone to catalyst of 5:1 under the conditions of a temperature of 90 ℃ and a pressure of 1.5MPa in an oxygen atmosphere and in the presence of a trace amount of hydrogen peroxide, wherein the molar ratio of oxygen to isopropanol is 40:1 and the molar ratio of hydrogen peroxide to acetophenone is 0.06: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 18
In a kettle reactor, acetophenone and isopropanol, 25 mass percent hydrochloric acid and the same catalyst TS-1 molecular sieve as in example 4 are reacted in an oxygen atmosphere at a molar ratio of acetophenone to isopropanol of 0.5:1, a molar ratio of hydrochloric acid (as HCl) to acetophenone of 0.0001:1, a weight ratio of acetophenone to catalyst of 20:1 at a temperature of 90 ℃ and a pressure of 1.5MPa, wherein the molar ratio of oxygen to isopropanol is 10: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
Example 19
Adding the catalyst TS-1 molecular sieve same as the catalyst in the example 4 into a mixed aqueous solution containing nitric acid and hydrogen peroxide, activating under stirring, and adding nitric acid (HNO) into the mixed aqueous solution3The molar ratio of hydrogen peroxide to water to TS-1 molecular sieve (calculated by silicon dioxide) is 0.5: 50:1, the treatment temperature is 30 ℃, the treatment time is 20 hours, and then the activated TS-1 molecular sieve is obtained by recovery. Compared with the titanium silicalite TS-1 of the example 1, the titanium silicalite TS-1 after the activation treatment has the advantages that the peak area of the absorption peak between 230 and 310nm in the UV-Vis spectrum is reduced by 5.0 percent, and the pore volume determined by a static nitrogen adsorption method is reduced by 3.4 percent.
In a kettle type reactor, reacting acetophenone, isopropanol and the activated TS-1 molecular sieve catalyst in a molar ratio of 0.01:1 and a weight ratio of 50:1 at 100 ℃ and under a pressure of 2MPa in an oxygen atmosphere, wherein the molar ratio of oxygen to isopropanol is 2: 1; samples were taken at 0.1 hour from the reaction and analyzed, the results of which are shown in Table 1.
Example 20
In a fixed bed reactor, acetophenone, isopropanol and a catalyst TS-1 molecular sieve which is the same as the catalyst in example 4 are added according to the molar ratio of the acetophenone to the isopropanol of 5:1, the weight ratio of the acetophenone to the catalyst of 10:1 and the total liquid hourly space velocity of 2h-1Reacting in an oxygen atmosphere at 40 ℃ and 0.5MPa, wherein the molar ratio of oxygen to isopropanol is 10: 1; samples were taken for 2 hours of reaction and the results are shown in Table 1.
TABLE 1
As can be seen from the results of examples 1-20, the preparation of phenyl acetate by the method of the present invention has the advantages of simple operation process, mild reaction conditions, high conversion rate of raw materials and high selectivity of products. The method is safe and efficient, and is suitable for large-scale industrial production and application.
The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.
It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.
In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.
Claims (43)
1. A method for preparing phenyl acetate is characterized by comprising the steps of carrying out contact reaction on acetophenone, isopropanol and oxygen in the presence of a catalyst, wherein the catalyst is a titanium silicalite catalyst;
the molar ratio of the acetophenone to the oxygen to the isopropanol is (0.01-10): (2-50): 1.
2. the process of claim 1, wherein the molar ratio of acetophenone, oxygen, and isopropanol is (0.05-0.5): (5-20): 1.
3. the method of claim 1, wherein the method further comprises: the reaction is carried out in the presence of hydrogen peroxide, and the molar ratio of the hydrogen peroxide to the acetophenone is (0.0001-0.1): 1.
4. a process as claimed in claim 3, wherein the molar ratio of hydrogen peroxide to acetophenone is (0.0005-0.05): 1.
5. the method of claim 1, wherein the method further comprises: firstly, mixing acetophenone, isopropanol and oxygen with inorganic acid containing halogen to obtain mixed materials, and then carrying out contact reaction on the mixed materials in the presence of the catalyst, wherein the molar ratio of the inorganic acid containing halogen to the acetophenone is (0.00001-0.1): 1.
6. the process of claim 5, wherein the molar ratio of the halogen-containing mineral acid to acetophenone is (0.0001-0.01): 1.
7. the method of claim 5 or 6, wherein the inorganic acid containing a halogen comprises at least one of hydrochloric acid, hydrobromic acid, hydrofluoric acid, and hydroiodic acid, and the mixing is carried out under the conditions: the mixing temperature is 20-100 deg.C, the mixing pressure is 0-2MPa, and the mixing time is 0.1-5 h.
8. The process of claim 7, wherein the halogen-containing mineral acid comprises hydrochloric acid and/or hydrobromic acid.
9. The method of claim 1, wherein the catalyst is an activated titanium silicalite catalyst, and the activation treatment comprises contacting the titanium silicalite with an aqueous solution containing an acid and optionally a peroxide, wherein the molar ratio of the acid, peroxide, water and titanium silicalite, calculated as silica, is (0.02-15): (0-10): (15-100): 1.
10. the method according to claim 9, wherein the acid is at least one selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, perchloric acid and C1-C5 carboxylic acids; the peroxide is at least one selected from hydrogen peroxide, tert-butyl hydroperoxide, cumyl peroxide and cyclohexyl hydroperoxide; the conditions of the activation treatment include: the titanium silicalite is contacted with an aqueous solution containing an acid and optionally a peroxide at a temperature of 0 to 90 ℃ for a time of 0.1 to 48 hours.
11. The method of claim 9 or 10, wherein the activation treatment comprises contacting the titanium silicalite with an aqueous solution containing nitric acid and peroxide, wherein the molar ratio of the nitric acid, the peroxide, the water and the titanium silicalite is (0.1-10): (0.01-5): (20-80): 1.
12. the method as claimed in claim 11, wherein the activation treatment reduces the peak area of the absorption peak of the titanium silicalite molecular sieve subjected to the activation treatment between 230-310nm by more than 2% in the ultraviolet-visible spectrum based on the titanium silicalite molecular sieve; the pore volume of the titanium silicalite molecular sieve subjected to the activation treatment is reduced by more than 1%, and the pore volume is determined by adopting a static nitrogen adsorption method.
13. The method as claimed in claim 12, wherein the activation treatment reduces the peak area of the absorption peak of the titanium silicalite molecular sieve subjected to the activation treatment between 230-310nm by 2-30% in the ultraviolet-visible spectrum based on the titanium silicalite molecular sieve.
14. The method as claimed in claim 13, wherein the activation treatment reduces the peak area of the absorption peak of the titanium silicalite molecular sieve subjected to the activation treatment between 230-310nm by 2.5-15% in the ultraviolet-visible spectrum based on the titanium silicalite molecular sieve.
15. The method as claimed in claim 14, wherein the activation treatment reduces the peak area of the absorption peak of the titanium silicalite molecular sieve subjected to the activation treatment between 230-310nm by 3-10% in the ultraviolet-visible spectrum based on the titanium silicalite molecular sieve.
16. The method as claimed in claim 15, wherein the activation treatment reduces the peak area of the absorption peak of the titanium silicalite molecular sieve subjected to the activation treatment between 230-310nm by 3-6% in the ultraviolet-visible spectrum based on the titanium silicalite molecular sieve.
17. The method of any one of claims 12 to 16, wherein the pore volume of the activated titanium silicalite molecular sieve is reduced by 1 to 20%, and the pore volume is determined by a static nitrogen adsorption method.
18. The method of claim 17, wherein the activated titanium silicalite molecular sieve has a pore volume reduction of 1.5 to 10%, as measured by static nitrogen adsorption.
19. The method of claim 18, wherein the activated titanium silicalite molecular sieve has a pore volume reduction of 2 to 5%, as measured by static nitrogen adsorption.
20. The process of claim 1 or 9, wherein the titanium silicalite molecular sieve is at least one selected from the group consisting of an MFI-type titanium silicalite molecular sieve, an MEL-type titanium silicalite molecular sieve, a BEA-type titanium silicalite molecular sieve, an MWW-type titanium silicalite molecular sieve, an MOR-type titanium silicalite molecular sieve, a TUN-type titanium silicalite molecular sieve, and a hexagonal structure titanium silicalite molecular sieve.
21. The method of claim 20, wherein the titanium silicalite molecular sieve is a titanium silicalite TS-1, the titanium silicalite TS-1 has a surface silicon-to-titanium ratio not lower than a bulk silicon-to-titanium ratio, the silicon-to-titanium ratio is a molar ratio of silicon oxide to titanium oxide, the surface silicon-to-titanium ratio is determined by X-ray photoelectron spectroscopy, and the bulk silicon-to-titanium ratio is determined by X-ray fluorescence spectroscopy;
the ratio of the surface silicon-titanium ratio to the bulk silicon-titanium ratio is more than 1.2.
22. The method of claim 21, wherein the ratio of the surface silicon to titanium ratio to the bulk silicon to titanium ratio is 1.2-5.
23. A method as claimed in claim 22 wherein the ratio of the surface silicon to titanium ratio to the bulk silicon to titanium ratio is in the range 1.5-4.5.
24. The method of any one of claims 21 to 23, wherein the titanium silicalite TS-1 is prepared by a method comprising:
(A) dispersing an inorganic silicon source in an aqueous solution containing a titanium source and an alkali source template agent, and optionally supplementing water to obtain a dispersion liquid, wherein the ratio of the silicon source: a titanium source: alkali source template agent: the molar ratio of water is 100: (0.5-8): (5-30): (100-2000), the inorganic silicon source is SiO2The titanium source is calculated as TiO2The alkali source template agent is calculated by OH < - > or N;
(B) standing the dispersion liquid obtained in the step (A) at 15-60 ℃ for 6-24 hours;
(C) and (3) sequentially carrying out stage (1), stage (2) and stage (3) crystallization on the dispersion liquid obtained in the step (A) or the dispersion liquid obtained in the step (B) in a sealed reaction kettle, wherein the stage (1) is crystallized for 6-72 hours at the temperature of 80-150 ℃, the stage (2) is cooled to the temperature of not higher than 70 ℃ and the retention time is at least 0.5 hour, the stage (3) is heated to the temperature of 120-phase and 200 ℃, and then the crystallization is carried out for 6-96 hours.
25. The method as claimed in claim 24, wherein in step (C), the crystallization temperature of the stage (1) is 110-140 ℃.
26. The method as claimed in claim 25, wherein in step (C), the crystallization temperature of the stage (1) is 120-140 ℃.
27. The method as claimed in claim 26, wherein in step (C), the crystallization temperature of the stage (1) is 130-140 ℃.
28. The process according to claim 24, wherein in step (C) the crystallization time of stage (1) is comprised between 6 and 8 hours.
29. The process according to claim 24, wherein in step (C) the residence time of said stage (2) is comprised between 1 and 5 hours.
30. The method as claimed in claim 24, wherein in step (C), the temperature of the stage (3) is raised to 140-180 ℃.
31. The method as claimed in claim 30, wherein in step (C), the temperature of the stage (3) is raised to 160-170 ℃.
32. The process of claim 24, wherein in step (C), the stage (3) recrystallizes for 12-20 hours.
33. The method of claim 24, wherein the phases (1) and (3) satisfy one or both of the following conditions:
condition 1: the crystallization temperature of the stage (1) is lower than the crystallization temperature of the stage (3);
condition 2: the crystallization time of the stage (1) is less than the crystallization time of the stage (3).
34. The method of claim 33, wherein condition 1 is: the crystallization temperature of the stage (1) is 10-50 ℃ lower than that of the stage (3).
35. The method of claim 34, wherein condition 1 is: the crystallization temperature of the stage (1) is 20-40 ℃ lower than that of the stage (3).
36. The method according to any one of claims 33 to 35, wherein condition 2 is: the crystallization time of stage (1) is 5-24 hours shorter than the crystallization time of stage (3).
37. The method of claim 36, wherein condition 2 is: the crystallization time of stage (1) is 6-12 hours shorter than the crystallization time of stage (3).
38. The method of claim 24, wherein the titanium source is an inorganic titanium salt selected from TiCl and/or an organic titanate4、Ti(SO4)2And TiOCl2At least one of the organic titanates of the general formula R7 4TiO4A compound of formula (I), R7Is an alkyl group having 2 to 4 carbon atoms; the alkali source template agent is at least one selected from quaternary ammonium hydroxide, aliphatic amine and aliphatic alcohol amine; the inorganic silicon source is silica gel and/or silica sol.
39. The method of claim 38, wherein the alkali-source templating agent is a quaternary ammonium base.
40. The method of claim 39, wherein the alkali-source templating agent is tetrapropylammonium hydroxide.
41. The process according to claim 1, wherein the weight ratio of isopropanol to catalyst is (1-100): 1.
42. the process of claim 41, wherein the weight ratio of isopropanol to catalyst is (5-40): 1.
43. the process according to claim 1, wherein the reaction conditions are: the reaction temperature is 10-160 ℃, the reaction pressure is 0.1-5MPa, and the reaction time is 0.1-10 h.
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| CN104944441A (en) * | 2014-03-31 | 2015-09-30 | 中国石油化工股份有限公司 | Method for synthesizing titanium-silicon molecular sieve |
| CN105085216A (en) * | 2014-05-08 | 2015-11-25 | 中国石油化工股份有限公司 | Method for simultaneously producing acetone and benzenediol |
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| JPH0625083A (en) * | 1992-07-10 | 1994-02-01 | Daicel Chem Ind Ltd | Production of ester or lactone |
| CN104944441A (en) * | 2014-03-31 | 2015-09-30 | 中国石油化工股份有限公司 | Method for synthesizing titanium-silicon molecular sieve |
| CN105085216A (en) * | 2014-05-08 | 2015-11-25 | 中国石油化工股份有限公司 | Method for simultaneously producing acetone and benzenediol |
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