CN109721514B

CN109721514B - Preparation method of sulfone

Info

Publication number: CN109721514B
Application number: CN201711043725.9A
Authority: CN
Inventors: 史春风; 林民; 朱斌
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2017-10-31
Filing date: 2017-10-31
Publication date: 2020-12-04
Anticipated expiration: 2037-10-31
Also published as: CN109721514A

Abstract

The invention discloses a preparation method of sulfone, which comprises the following steps: providing a reaction feed comprising at least one thioether, at least one oxidant, and optionally at least one solvent; enabling reaction feed to enter a 1 st catalyst bed layer and flow through the 1 st catalyst bed layer to an n catalyst bed layer, filling a catalyst containing a molecular sieve in the catalyst bed layer, dividing the feed of the 1 st catalyst bed layer into a 1 st material flow to an f material flow when the total pressure drop of the catalyst bed layer is higher than the initial total pressure drop, enabling the 1 st material flow to enter the 1 st catalyst bed layer, and enabling the rest material flows except the 1 st material flow to enter a catalyst bed layer positioned at the downstream of the 1 st catalyst bed layer. The method of the invention is adopted to oxidize the thioether to prepare the sulfone, which can effectively inhibit the trend of pressure drop increase of a catalyst bed layer in the long-time continuous reaction process, reduce the energy consumption of a system and prolong the stable operation time of a device.

Description

Preparation method of sulfone

Technical Field

The invention relates to a preparation method of sulfone.

Background

As a typical representative of sulfones, dimethyl sulfone is a white crystalline powder, readily soluble in water, ethanol, benzene, methanol and acetone, and slightly soluble in ether. The potassium permanganate can not be discolored at normal temperature, and the dimethyl sulfone can be oxidized into methanesulfonic acid by a strong oxidant. Dimethyl sulfone is industrially used as a high-temperature solvent and raw material for organic synthesis, a gas chromatography stationary liquid, an analytical reagent, a food additive, and a drug. Dimethyl sulfone, as an organic sulfide, has the functions of enhancing the human body's ability to produce insulin, and promoting the metabolism of saccharides, and is an essential substance for the synthesis of human collagen. Dimethyl sulfone can promote wound healing, and also has effects on the synthesis and activation of vitamin B, vitamin C, and biotin required for metabolism and nerve health, and is called "natural beautifying carbon substance". The skin, hair, nails, bones, muscles and organs of a human body contain dimethyl sulfone, the dimethyl sulfone mainly exists in the sea and soil in the nature and is absorbed as nutrient substances in the growth of plants, the dimethyl sulfone can be taken by the human body from vegetables, fruits, fish, meat, eggs, milk and other foods, health disorder or diseases can be caused once the dimethyl sulfone is deficient, the dimethyl sulfone is a main substance for maintaining the balance of biological sulfur elements of the human body, has therapeutic value and health care function on human diseases, and is a necessary medicine for human survival and health guarantee.

Disclosure of Invention

CN105523974A discloses contacting dimethyl sulfide and an oxidant with a titanium silicalite in a fixed bed reactor to obtain dimethyl sulfone. However, in the actual operation process, the inventor of the present invention finds that when the dimethyl sulfide and the oxidant are in contact reaction with the titanium silicalite molecular sieve in the fixed bed reactor, the pressure drop of the catalyst bed layer is increased along with the extension of the reaction time, which results in the increase of the energy consumption of the system on one hand and reduces the operation stability and the safety of the reactor on the other hand.

The invention aims to overcome the technical problems that when a fixed bed reactor is adopted to carry out contact reaction between thioether and an oxidant and a molecular sieve to prepare sulfone, the pressure drop of a catalyst bed layer is increased along with the extension of reaction time, so that the energy consumption of a system is increased and the operation stability and safety of the reactor are influenced, and provides a sulfone preparation method.

The invention provides a preparation method of sulfone, which comprises the following steps:

providing a reaction feed comprising at least one thioether, at least one oxidant, and optionally at least one solvent, in a molar ratio of oxidant to thioether of greater than 2;

feeding the reaction feed into a 1 st catalyst bed and flowing through the 1 st to the nth catalyst bed under oxidation reaction conditions to obtain a product stream comprising sulphones, n being an integer greater than 2, said catalyst beds being packed with at least one catalyst comprising a molecular sieve,

when the total pressure drop of the catalyst bed is higher than the initial total pressure drop, carrying out a shunting operation, wherein the shunting operation comprises the steps of dividing the feeding material of the 1 st catalyst bed into 1 st material flow to f th material flow, wherein f is an integer more than 2, the 1 st material flow enters the 1 st catalyst bed and sequentially flows through the 1 st catalyst bed and the catalyst bed positioned at the downstream of the 1 st catalyst bed, and the rest material flows except the 1 st material flow enter the catalyst bed positioned at the downstream of the 1 st catalyst bed and sequentially flows through the catalyst bed and the catalyst bed positioned at the downstream of the catalyst bed.

The method of the invention is adopted to oxidize the thioether to prepare the sulfone, which can effectively inhibit the trend of pressure drop increase of a catalyst bed layer in the long-time continuous reaction process, reduce the energy consumption of a system and prolong the stable operation time of a device.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In the present invention, the term "at least one" means one or two or more.

The present invention provides a process for the preparation of a sulfone comprising providing a reaction feed comprising at least one thioether, at least one oxidant and optionally at least one solvent.

The thioether refers to a compound containing an-S-bond in the molecular structure, and preferably, the thioether is selected from thioether with 2-18 carbon atoms, and more preferably dimethyl thioether and/or dimethyl sulfide.

The oxidizing agent can be any of a variety of materials sufficient to oxidize the thioether to the sulfone. The process of the present invention is particularly useful in the preparation of sulfones by oxidation of sulfides using peroxides as oxidizing agents. The peroxide is a compound containing an-O-O-bond in the molecular structure, and can be selected from hydrogen peroxide, organic peroxide and peracid. The organic peroxide is obtained by substituting one or two hydrogen atoms in a hydrogen peroxide molecule with an organic group. The peracid refers to an organic oxyacid having an-O-O-bond in the molecular structure. Specific examples of the peroxide may include, but are not limited to: one or more of hydrogen peroxide, tert-butyl hydroperoxide, cumyl peroxide, cyclohexyl hydroperoxide, peroxyacetic acid and peroxypropionic acid. Preferably, the oxidizing agent is hydrogen peroxide. The hydrogen peroxide may be hydrogen peroxide commonly used in the art in various forms, such as hydrogen peroxide provided in the form of hydrogen peroxide.

According to the process of the invention, the molar ratio of the oxidizing agent to the thioether is greater than 2, preferably between 2.1 and 5: 1, more preferably 2.2 to 3: 1.

the reaction feed may or may not contain a solvent. The reaction feed preferably contains at least one solvent from the viewpoint of further improving the degree of mixing between the reactants in the reaction system, enhancing diffusion, and more conveniently adjusting the severity of the reaction. The kind of the solvent is not particularly limited. In general, the solvent may be selected from water, C₁-C₆Alcohol of (1), C₃-C₈Ketone and C₂-C₆A nitrile of (a). Specific examples of the solvent may include, but are not limited to: water, methanol, ethanol, n-propanol, isopropanol, tert-butanol, isobutanol, acetone, butanone and acetonitrile.

The amount of the solvent to be used is not particularly limited and may be conventionally selected. Generally, the mass ratio of solvent to thioether may be from 1 to 200: 1, preferably 5 to 100: 1, more preferably 8 to 60: 1, more preferably 10 to 30: 1.

according to the process of the present invention, the reaction feed is passed into the 1 st catalyst bed and flows through the 1 st to the nth catalyst bed under oxidation reaction conditions to obtain a product stream containing sulfones. In the present invention, n is an integer of 2 or more, and n may be an integer of 2 to 50, preferably 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, more preferably 2, 3, 4, 5, 6, 7, 8, 9, or 10, further preferably 2, 3, 4, or 5, and is, for example, 2.

According to the process of the invention, the catalyst bed is packed with at least one catalyst comprising a molecular sieve.

According to the method, the catalyst bed layer can be filled with inert filler besides the catalyst containing the molecular sieve, so that the content of the catalyst containing the molecular sieve in the catalyst bed layer can be adjusted. The inert packing can be any of the various packing materials commonly used, and can be selected from, for example, raschig rings, pall rings, ladder rings, arc saddles, intalox saddles, and metal ring intalox saddles. Specific examples of the filler may be a theta ring and/or a beta ring. The loading of the inert filler can be suitably selected according to the desired reaction rate and the throughput of the reaction zone so as to meet the specific use requirements.

The catalyst containing the molecular sieve can be a catalyst which has catalytic activity on thioether oxidation reaction and takes the molecular sieve as an active component, can be a formed catalyst, and can also be raw powder of the molecular sieve.

The shaped catalyst contains a molecular sieve as an active ingredient and a carrier as a binder, wherein the content of the molecular sieve can be selected conventionally. Generally, the molecular sieve may be present in an amount of from 5 to 95 wt%, preferably from 10 to 95 wt%, more preferably from 70 to 90 wt%, based on the total amount of the shaped catalyst; the carrier may be contained in an amount of 5 to 95% by weight, preferably 5 to 90% by weight, more preferably 10 to 30% by weight. The support for the shaped catalyst may be of conventional choice, such as alumina and/or silica. Methods for preparing the shaped catalysts are well known in the art and will not be described in detail herein. The particle size of the shaped catalyst is not particularly limited, and may be appropriately selected depending on the specific shape. In general, the shaped catalyst may have an average particle size of from 4 to 5000 microns, preferably from 5 to 2000 microns, such as from 40 to 1000 microns. The average particle size is a volume average particle size and can be measured by a laser particle sizer.

Specific examples of the molecular sieve in the molecular sieve-containing catalyst may include, but are not limited to: one or more than two of titanium silicalite molecular sieve, vanadium silicalite molecular sieve and vanadium titanium silicalite molecular sieve.

In the present invention, a titanium silicalite is a generic term for a type of zeolite in which a part of silicon atoms in a lattice framework is substituted with titanium atoms. The content of titanium atoms in the titanium silicalite molecular sieve is not particularly limited in the invention, and can be selected conventionally in the field.

In the present invention, the titanium silicalite molecular sieve can be common titanium silicalite molecular sieves with various topologies, such as: the titanium silicalite molecular sieve can be one or more than two of a titanium silicalite molecular sieve with an MFI structure (such as TS-1), a titanium silicalite molecular sieve with an MEL structure (such as TS-2), a titanium silicalite molecular sieve with a BEA structure (such as Ti-Beta), a titanium silicalite molecular sieve with an MWW structure (such as Ti-MCM-22), a titanium silicalite molecular sieve with a hexagonal structure (such as Ti-MCM-41 and Ti-SBA-15), a titanium silicalite molecular sieve with an MOR structure (such as Ti-MOR), a titanium silicalite molecular sieve with a TUN structure (such as Ti-TUN) and a titanium silicalite molecular sieve with other structures (such as Ti-ZSM-48). Preferably, the titanium silicalite molecular sieve is a titanium silicalite molecular sieve of MFI structure, such as titanium silicalite molecular sieve TS-1.

In the titanium silicalite molecular sieve, the ratio of silicon element: the molar ratio of the titanium element may be 100: 0.5-10, preferably 100: 1-8, more preferably 100: 1.2 to 6, more preferably 100: 2-4.

In the present invention, the term "vanadium-silicon molecular sieve" refers to a generic term for a zeolite having vanadium atoms substituted for a part of silicon atoms in the lattice framework. The vanadium silicalite molecular sieve can be common vanadium silicalite molecular sieves with various topologies, such as: the vanadium-silicon molecular sieve can be one or more than two of vanadium-silicon molecular sieve with MFI structure (such as VS-1), vanadium-silicon molecular sieve with MEL structure (such as VS-2), vanadium-silicon molecular sieve with BEA structure (such as V-beta), vanadium-silicon molecular sieve with MWW structure (such as V-MCM-22), vanadium-silicon molecular sieve with hexagonal structure (such as V-MCM-41 and V-SBA-15) and vanadium-silicon molecular sieve with MOR structure (such as V-MOR). Preferably, the vanadium-silicon molecular sieve is a vanadium-silicon molecular sieve of MFI structure.

In the vanadium-silicon molecular sieve, the ratio of silicon element: the molar ratio of the vanadium element may be 100: 0.01 to 5, preferably 100: 0.2-2.5, more preferably 100: 0.5 to 2, more preferably 100: 0.6-1.

In the invention, the vanadium-titanium-silicon molecular sieve contains vanadium element, titanium element and silicon element, and the vanadium element and the titanium element replace part of the silicon element in the lattice framework. The vanadium titanium silicalite molecular sieve can be common vanadium titanium silicalite molecular sieves with various topological structures, such as: the vanadium-titanium-silicon molecular sieve can be one or more than two of a vanadium-titanium-silicon molecular sieve with an MFI structure, a vanadium-titanium-silicon molecular sieve with an MEL structure, a vanadium-titanium-silicon molecular sieve with a BEA structure, a vanadium-titanium-silicon molecular sieve with an MWW structure, a vanadium-titanium-silicon molecular sieve with a hexagonal structure, a vanadium-titanium-silicon molecular sieve with an MOR structure, a vanadium-titanium-silicon molecular sieve with a TUN structure and a vanadium-titanium-silicon molecular sieve with other structures. Preferably, the vanadium-titanium-silicon molecular sieve is a vanadium-titanium-silicon molecular sieve with an MFI structure.

In the vanadium-titanium-silicon molecular sieve, the ratio of silicon element: titanium element: the molar ratio of the vanadium element may be 100: 0.5-10: 0.01 to 5, preferably 100: 1-8: 0.2-2.5, more preferably 100: 1.2-6: 0.5-2.

According to the method, from the viewpoint of further improving the selectivity of the sulfone, the molecular sieve is a vanadium-silicon molecular sieve and/or a vanadium-titanium-silicon molecular sieve.

In a preferred embodiment, the molecular sieve is a vanadium-titanium-silicon molecular sieve, and the vanadium-titanium-silicon molecular sieve satisfies X_1-1.8/X_0.4-0.9＝C，0.05<C<0.5，X_0.4-0.9The ratio of the pore diameter of micropores in the range of 0.4-0.9nm in the molecular sieve to the distribution of the total pore diameter, X_1-1.8Is the proportion of the pore diameter of the micropores of the molecular sieve in the range of 1-1.8nm in the distribution quantity of the pore diameter of the total micropores. Preferably, 0.1. ltoreq. C.ltoreq.0.48.

According to the vanadium titanium silicalite molecular sieves of this preferred embodiment, the vanadium titanium silicalite molecular sieves satisfy T_w/T_k＝D，0.3<D<0.7, more preferably 0.4. ltoreq. D.ltoreq.0.6, still more preferably 0D is more than or equal to 5 and less than or equal to 0.6, wherein T_wIs the micropore volume of the molecular sieve, T_kIs the total pore volume of the molecular sieve.

In the present invention, the micropore diameter and micropore pore volume are N₂And (4) measuring by a static adsorption method. According to this preferred embodiment, the proportion of the pore size distribution of the micropores to the total pore size distribution in the range of 1 to 1.8nm<At 1%, the pore distribution of the micropores is negligible, i.e., no micropore distribution in the range of 1 to 1.8nm is considered. The microporous molecular sieve prepared by conventional direct hydrothermal synthesis has the ratio of the micropore size distribution to the total micropore size distribution in the range of 1-1.8nm<1 percent, the microporous molecular sieve which is treated and modified by a common treatment and modification method has lower proportion of the micropore size distribution in the total micropore size distribution within the range of 1-1.8nm, and is generally the microporous molecular sieve<1％。

The vanadium titanium silicalite molecular sieve according to this preferred embodiment can be made by a process comprising the steps of:

(1) contacting a titanium silicalite with an acid solution at a temperature of from 40 ℃ to 200 ℃, preferably from 50 ℃ to 180 ℃, more preferably from 60 ℃ to 180 ℃, and even more preferably from 80 ℃ to 100 ℃, and separating a solid phase from the mixture resulting from the contacting;

(2) and (2) mixing the solid phase obtained by separation in the step (1) with a silicon source, a titanium source, a vanadium source, an alkali source and water, and then carrying out hydrothermal treatment.

In the step (1), the titanium silicalite molecular sieve can be a fresh titanium silicalite molecular sieve and/or a non-fresh titanium silicalite molecular sieve. The fresh titanium silicalite molecular sieve refers to a titanium silicalite molecular sieve which is not used for catalytic reaction; the non-fresh titanium silicalite molecular sieve refers to a titanium silicalite molecular sieve which has undergone a catalytic reaction. Specific examples of the non-fresh titanium silicalite molecular sieves can include, but are not limited to: a titanium silicalite molecular sieve (hereinafter referred to as a regenerant) which is temporarily inactivated during the catalytic reaction and has activity recovered after regeneration; titanium silicalite molecular sieves which are permanently deactivated during the catalytic reaction and cannot recover their activity even if regenerated (hereinafter referred to as "discharge agents"); and combinations of regenerants and discharge agents. Preferably, the titanium silicalite molecular sieve is a non-fresh titanium silicalite molecular sieve.

The permanently deactivated titanium silicalite molecular sieves discharged from a plant using titanium silicalite molecular sieves as catalysts are called discharging agents, which are used as waste molecular sieves and are usually disposed of in a landfill. The inventor of the invention finds that the discharging agent can be used as a raw material for producing the vanadium-titanium-silicon molecular sieve, and the prepared vanadium-titanium-silicon molecular sieve can further delay the trend of pressure drop increase of a catalyst bed layer when being used as a catalyst for thioether oxidation reaction. Therefore, in step (1), the titanium silicalite molecular sieve is more preferably a discharge agent. The discharging agent may be discharged from various reaction apparatuses using a titanium silicalite as a catalyst, and may be discharged from an oxidation reaction apparatus, for example. Specifically, the discharging agent may be one or more of a discharging agent of an ammoximation reaction apparatus, a discharging agent of a hydroxylation reaction apparatus, and a discharging agent of an epoxidation reaction apparatus. More specifically, the discharging agent may be one or more of a discharging agent of a cyclohexanone ammoximation reaction apparatus, a discharging agent of a phenol hydroxylation reaction apparatus, and a discharging agent of a propylene epoxidation reaction apparatus.

From the viewpoint of further improving the catalytic performance of the finally prepared vanadium-titanium-silicon molecular sieve, in the step (1), the titanium-silicon molecular sieve is further preferably a discharging agent of a reaction device which performs a reaction under an alkaline environment and takes the titanium-silicon molecular sieve as a catalyst. Particularly preferably, the discharging agent is a discharging agent of an ammoximation reaction device, such as a discharging agent of a cyclohexanone ammoximation reaction device.

The stripper is preferably subjected to high temperature calcination and/or solvent washing to remove residual materials attached to the stripper surface and/or in the channels before being used in contact with the acid solution. In one example, the discharging agent is calcined prior to contacting with the acid solution, and the calcination may be performed at a temperature of 300-800 ℃, preferably at a temperature of 350-700 ℃, and more preferably at a temperature of 450-650 ℃. The duration of the calcination may be from 1 to 12 hours, preferably from 1.5 to 6 hours. The calcination may be performed in an air atmosphere or an inert atmosphere. The inert atmosphere may be an atmosphere formed of nitrogen and/or a group zero element gas, such as argon.

The activity of the discharging agent varies according to its origin. Generally, the activity of the discharging agent can be 5-95% of the activity of the titanium silicalite molecular sieve in the fresh state (i.e., the activity of the fresh titanium silicalite molecular sieve), such as 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, (i.e., the activity of the fresh titanium silicalite molecular sieve is 5-95%, 6%, 7%, 8%, 9%, 30%, 31%, 34%, 35%, 40, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94% or 95%. Preferably, the activity of the regenerated discharging agent can be 10-90% of the activity of the titanium silicalite molecular sieve when fresh. Further preferably, the activity of the regenerated discharging agent can be less than 60% of the activity of the titanium silicalite molecular sieve when fresh. Even more preferably, the activity of the regenerated discharging agent can be 30-55% of the activity of the titanium silicalite molecular sieve when fresh. When the activity of the regenerated discharging agent is 30-55% of that of the titanium-silicon molecular sieve in the fresh state, better effect of delaying the pressure drop rise of the catalyst bed layer can be obtained. It is particularly preferred that the activity of the regenerated discharging agent is 35 to 50% of the activity of the titanium silicalite when fresh. The activity of the fresh titanium silicalite molecular sieve is generally above 90%, usually above 95%.

The activity was determined by the following method: respectively using the regenerated discharging agent and the fresh titanium silicalite molecular sieve as catalysts of cyclohexanone ammoximation reaction, wherein the ammoximation reaction conditions are as follows: titanium silicalite molecular sieve, 36 wt% ammonia (as NH)₃Calculated as H), 30 wt% of hydrogen peroxide (calculated as H)₂O₂Calculated by mass ratio of 1: 7.5: 10:7.5: 10, reacting for 2h at 80 ℃ under atmospheric pressure. Respectively calculating the conversion rate of cyclohexanone when the regenerated discharging agent and the fresh titanium silicalite molecular sieve are used as catalysts, and respectively using the conversion rate as the activity of the regenerated discharging agent and the activity of the fresh titanium silicalite molecular sieve, wherein the conversion rate of the cyclohexanone is [ (the molar weight of the added cyclohexanone-the molar weight of the unreacted cyclohexanone)/the molar weight of the added cyclohexanone]×100％。

In the step (1), the titanium silicalite molecular sieve is preferably a titanium silicalite molecular sieve with an MFI structure, and more preferably TS-1. The method for treating the TS-1, particularly treating the discharging agent of the TS-1 can further prolong the one-way service life of the molecular sieve and prolong the regeneration period of the catalyst.

In the step (1), the acid solution refers to an aqueous solution containing an acid. The acid is a generalized acid and can be one or more than two of inorganic acid and organic acid. The organic acid may be one or more of carboxylic acid, sulfonic acid and peracid, such as C₁-C₆Aliphatic carboxylic acid of (1), C₆-C₁₂Aromatic carboxylic acid of (2), C₁-C₆Aliphatic sulfonic acid of (2), C₆-C₁₂Aromatic sulfonic acids, peroxyacetic acid and peroxypropionic acid. Preferably, the acid is HCl, H₂SO₄、HNO₃、CH₃COOH、HClO₄、H₃PO₄One or more than two of peroxyacetic acid and peroxypropionic acid. More preferably, the acid is HCl, HNO₃And H₃PO₄One or more than two of them. The acid is preferably provided in the form of an aqueous solution, and the concentration of the acid in the aqueous acid solution may be selected depending on the kind of the acid, and is not particularly limited, and generally, the concentration of the acid in the aqueous acid solution may be 0.5 to 20mol/L, and preferably 1 to 15 mol/L.

In the step (1), the titanium silicalite molecular sieve: the molar ratio of the acids may be 100: 0.005 to 50, preferably 100: 0.1 to 30, more preferably 100: 2-15, more preferably 100: 6-12. The titanium-silicon molecular sieve is made of SiO₂In terms of H, the acid is⁺And (6) counting.

In step (1), the duration of the contact may be selected according to the temperature of the contact. Generally, the duration of the contact may be from 0.5 to 36 hours, preferably from 1 to 24 hours, more preferably from 1 to 18 hours, and still more preferably from 2 to 12 hours.

In the step (1), the contact may be performed in an air atmosphere, or may be performed in an inert atmosphere, and is preferably performed in an air atmosphere.

In step (1), the solid phase can be separated from the mixture obtained by the contact by a conventional method. For example, the contacted mixture may be filtered and/or centrifuged to separate the solid phase therefrom.

In the step (2), the silicon source is an organic silicon source. The organic silicon source can be various substances capable of forming silicon dioxide under hydrolytic condensation conditions, for example, a silicon-containing compound shown in formula I,

in the formula I, R₁、R₂、R₃And R₄Each is C₁-C₄Alkyl group of (1). Said C is₁-C₄Alkyl of (2) includes C₁-C₄Straight chain alkyl of (2) and C₃-C₄Specific examples thereof may include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl.

Preferably, the silicon source is selected from the group consisting of methyl orthosilicate, ethyl orthosilicate, n-propyl orthosilicate, isopropyl orthosilicate, and n-butyl orthosilicate.

Solid phase separated in the step (1): the molar ratio of the silicon source may be 100: 3-40, preferably 100: 5-30, the solid phase separated in the step (1) and the silicon source are SiO₂And (6) counting.

In the step (2), the titanium source can be a titanium source commonly used in the technical field of molecular sieve preparation. In particular, the titanium source may be an organic titanium source (e.g. an organic titanate) and/or an inorganic titanium source (e.g. an inorganic titanium salt). The inorganic titanium source may be TiCl₄、Ti(SO₄)₂、TiOCl₂One or more of titanium hydroxide, titanium oxide, titanium nitrate and titanium phosphate. The organic titanium source can be one or more than two of fatty titanium alkoxide and organic titanate. The titanium source is preferably an organic titanium source, more preferably an organic titanate, and even more preferably of the formula M₄TiO₄The organic titanate shown, wherein 4M can be same or different, and each is preferably C₁-C₄Alkyl group of (1). The titanium source is more preferably one or more of titanium sulfate, titanium tetrachloride, tetraisopropyl titanate, tetra-n-propyl titanate, tetrabutyl titanate, and tetraethyl titanate.

Solid phase separated in the step (1): the molar ratio of the titanium source may be 100: 0.1 to 8, preferably 100: 0.2-5. The titanium source is TiO₂Metering the solid phase separated in the step (1) with SiO₂And (6) counting.

In the step (2), the vanadium source is vanadium oxide, vanadium halide, or vanadium acid (metavanadate, HVO)₃) Orthovanadic acid (H)₃VO₄) Pyrovanadic acid (H)₄V₂O₇、H₃V₃O₉) One or more of vanadate (corresponding salt to vanadate), carbonate of vanadium, nitrate of vanadium, sulfate of vanadium, phosphate of vanadium and hydroxide of vanadium. Specific examples of the vanadium source may include, but are not limited to, one or more of sodium vanadate, ammonium metavanadate, vanadium pentoxide, vanadium oxytrichloride, potassium metavanadate, vanadyl sulfate, vanadium acetylacetonate, and vanadium tetrachloride. Preferably, the vanadium source is one or more than two of ammonium metavanadate, sodium vanadate and potassium metavanadate.

Solid phase separated in the step (1): the molar ratio of the vanadium source may be 100: 0.1 to 10, preferably 100: 0.3 to 5, more preferably 100: 0.5-2. The vanadium source is V₂O₅Metering the solid phase separated in the step (1) with SiO₂And (6) counting.

In the step (2), the alkali source may be an alkali source commonly used in the technical field of molecular sieve preparation. Specifically, the alkali source may be an organic alkali source and/or an inorganic alkali source, wherein the inorganic alkali source may be one or more of ammonia, an alkali whose cation is an alkali metal, and an alkali whose cation is an alkaline earth metal. Specific examples of the inorganic alkali source may include, but are not limited to, one or more of ammonia, sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, and barium hydroxide. The organic alkali source can be one or more than two of urea, amine, alcohol amine and quaternary ammonium base.

The quaternary ammonium base can be various organic quaternary ammonium bases, the amine can be a compound containing one amino group in the molecular structure, and the alcohol amine can be a compound containing at least one amino group and at least one hydroxyl group in the molecular structure.

Specifically, the quaternary ammonium base can be a quaternary ammonium base shown in a formula II,

in the formula II, R₅、R₆、R₇And R₈Are the same or different and are each C₁-C₄Alkyl of (2) including C₁-C₄Straight chain alkyl of (2) and C₃-C₄Branched alkyl groups of (a), for example: r₅、R₆、R₇And R₈Each may be methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl.

The amine may be an aliphatic amine of formula III,

R⁹(NH₂)_n(formula III)

In the formula III, n is an integer of 1 or 2. When n is 1, R⁹Is C₁-C₆Alkyl of (2) including C₁-C₆Straight chain alkyl of (2) and C₃-C₆Such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, isopentyl, tert-pentyl and n-hexyl. When n is 2, R⁹Is C₁-C₆Alkylene of (2) including C₁-C₆Linear alkylene of (A) and (C)₃-C₆Such as methylene, ethylene, n-propylene, n-butylene, n-pentylene or n-hexylene.

The alcohol amine may be an aliphatic alcohol amine represented by formula IV,

(HOR¹⁰)_mNH_(3-m)(formula IV)

In the formula IV, m are R¹⁰Are the same or different and are each C₁-C₄Alkylene of (2) including C₁-C₄Linear alkylene of (A) and (C)₃-C₄Branched alkylene groups of (a), such as methylene, ethylene, n-propylene and n-butylene; m is 1, 2 or 3. More preferably, the aliphatic alcohol amine compound is one or more of monoethanolamine, diethanolamine and triethanolamine.

Specific examples of the alkali source may include, but are not limited to, one or more of ammonia, sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, barium hydroxide, urea, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, ethylamine, n-butylamine, butanediamine, hexamethylenediamine, monoethanolamine, diethanolamine, and triethanolamine.

In a preferred embodiment, the alkali source is preferably one or more of sodium hydroxide, ammonia water, ethylenediamine, n-butylamine, butanediamine, hexamethylenediamine, monoethanolamine, diethanolamine, triethanolamine, tetraethylammonium hydroxide and tetrapropylammonium hydroxide, from the viewpoint of further improving the catalytic activity of the finally prepared vanadium-titanium-silicon molecular sieve.

Solid phase separated in the step (1): the molar ratio of the alkali source may be 100: 0.5 to 50, preferably 100: 1-40, more preferably 100: 5-30. The alkali source is N or OH^-Wherein, when the alkali source contains nitrogen element, the alkali source is counted by N, and when the alkali source does not contain nitrogen element, the alkali source is counted by OH^-Metering the solid phase separated in the step (1) with SiO₂And (6) counting.

In the step (2), the order of mixing the solid phase separated in the step (1), the titanium source, the vanadium source, the alkali source and water is not particularly limited. From the viewpoint of further improving the catalytic activity of the finally prepared vanadium-titanium-silicon molecular sieve, it is preferable to mix a silicon source, a titanium source and a vanadium source, mix the obtained mixture with an alkali source and water, mix the obtained mixture with the solid phase separated in step (1), and perform hydrothermal treatment.

In the step (2), the titanium-silicon molecular sieve is subjected to hydrothermal treatment with a silicon source, a titanium source, a vanadium source and an alkali source. The amount of water may be conventionally selected. Generally, the solid phase separated in step (1): the molar ratio of water may be 100: 20-1000, preferably 100: 50-950, more preferably 100: 100-900, more preferably 100: 200 ℃ 800. the solid phase separated in step (1) is SiO₂And (6) counting.

In step (2), the hydrothermal treatment may be performed at a temperature of 100-200 ℃, preferably at a temperature of 120-180 ℃, and more preferably at a temperature of 130-170 ℃. The duration of the hydrothermal treatment may be selected according to the temperature of the hydrothermal treatment. Generally, the duration of the hydrothermal treatment may be 0.5 to 96 hours, preferably 6 to 72 hours, more preferably 8 to 56 hours, and further preferably 12 to 24 hours.

In the step (2), the hydrothermal treatment is performed under a closed condition. The hydrothermal treatment may be carried out under autogenous pressure, or may be carried out under an additional increased pressure, preferably under autogenous pressure. In practical operation, the hydrothermal treatment may be performed in an autoclave.

And (3) treating the mixture obtained by the hydrothermal treatment in the step (2) by adopting a conventional method to obtain the vanadium-titanium-silicon molecular sieve. Specifically, the mixture obtained by the hydrothermal treatment may be subjected to solid-liquid separation, and the obtained solid phase is washed, dried and optionally calcined, so as to obtain the vanadium-titanium-silicon molecular sieve. The drying may be carried out under conventional conditions, and in general, the drying may be carried out at a temperature of from 50 to 200 ℃, preferably at a temperature of from 80 to 180 ℃, more preferably at a temperature of from 100 ℃ to 160 ℃. The duration of the drying may be 0.5 to 6 hours, preferably 1 to 3 hours. The calcination may be carried out at a temperature of 300-800 deg.C, preferably at a temperature of 400-600 deg.C. The duration of the calcination may be 2 to 12 hours, preferably 3 to 6 hours. The calcination may be performed in an air atmosphere or an inert atmosphere.

Compared with a titanium silicalite molecular sieve, the vanadium-titanium silicalite molecular sieve of the preferred embodiment is used as an active component of the catalyst containing the molecular sieve, so that the sulfone selectivity can be further improved, and particularly, the vanadium-titanium silicalite molecular sieve of the preferred embodiment is used as the catalyst to obtain higher sulfone selectivity at a lower reaction temperature (such as not higher than 60 ℃ and preferably not higher than 55 ℃) and also obtain a better effect of inhibiting the pressure drop of a catalyst bed layer from rising. Compared with vanadium-titanium-silicon molecular sieves and conventional vanadium-titanium-silicon molecular sieves, the vanadium-titanium-silicon molecular sieve according to the preferred embodiment can obtain better catalytic effect, and can further delay the rising trend of the total pressure drop of the catalyst bed layer.

According to the method, the catalyst containing the molecular sieve is used in an amount capable of realizing a catalytic function. In general, the weight hourly space velocity of the thioethers may be from 0.1 to 300h^-1Preferably 1 to 150h^-1More preferably 5 to 100h^-1More preferably 10 to 80 hours^-1The weight hourly space velocity is based on the total amount of molecular sieve-containing catalyst loaded in the entire catalyst bed.

According to the method, when the total pressure drop of the catalyst bed is higher than the initial total pressure drop, a shunting operation is carried out, wherein the shunting operation comprises the steps of dividing the feeding of the 1 st catalyst bed into the 1 st material flow to the f material flow, enabling the 1 st material flow to enter the 1 st catalyst bed and sequentially flow through the 1 st catalyst bed and the catalyst bed positioned at the downstream of the 1 st catalyst bed, and enabling the rest material flows except the 1 st material flow to enter the catalyst bed positioned at the downstream of the 1 st catalyst bed and sequentially flow through the catalyst bed and the catalyst bed positioned at the downstream of the catalyst bed. When the total pressure drop of the catalyst bed layer is increased, the diversion operation can effectively inhibit the total pressure drop rising trend of the catalyst bed layer, so that the total pressure drop which originally shows the rising trend falls back, and the stable operation time of the device is prolonged. In the present invention, the total pressure drop of the catalyst beds means the pressure drop from the 1 st catalyst bed to the n-th catalyst bed.

In a preferred embodiment of the method according to the present invention, the splitting operation is preferably performed when the total pressure drop of the catalyst bed satisfies the following conditions from the viewpoint of reducing the frequency of the splitting operation, on the premise that the increase in the total pressure drop of the catalyst bed can be effectively suppressed: total pressure drop Δ P at a certain time t_tWith initial value of total pressure drop Δ P₀Has a ratio of Δ P_t/ΔP₀，1.1≤ΔP_t/ΔP₀Less than or equal to 5; preferably, 1.2. ltoreq. Δ P_t/ΔP₀Less than or equal to 3; more preferably, 1.2. ltoreq. Δ P_t/ΔP₀Less than or equal to 2.5. The initial value of the total pressure drop depends on the details of the reaction apparatus, and generally, Δ P₀Is not higher than 100kPa, more preferably not higher than 80kPa, still more preferably not higher than 60 kPa. Generally,. DELTA.P₀Is 5 to 50kPa, preferably 8 to 30kPa, more preferably 10 to 25 kPa.

According to the process of the present invention, f represents the highest number of streams other than the 1 st stream, which are separated from the feed to the 1 st catalyst bed, for example: when f is 3, the method is used for dividing the feed of the 1 st catalyst bed into a 1 st material flow, a 2 nd material flow and a 3 rd material flow, wherein the 1 st material flow enters the 1 st catalyst bed, and the 2 nd material flow and the 3 rd material flow enter the catalyst bed positioned at the downstream of the 1 st catalyst bed. f may be an integer of 2 or more, preferably an integer of 2 to 10, such as 2, 3, 4, 5, 6, 7, 8, 9 or 10. More preferably, f is an integer from 2 to 6, for example 2. The value of f in each splitting operation can be selected according to the amount of the remaining material flow, the number of the catalyst bed layers and the feeding position of the remaining material flow (namely, the catalyst bed layer into which the remaining material flow flows). When the amount of the remaining stream and the number of the catalyst beds are small and/or the inflow position of the remaining stream is single, the value of f may be small, for example, 2 to 5, preferably 2 to 3, and more preferably 2 (i.e., the feed to the 1 st catalyst bed is divided into the 1 st stream and the 2 nd stream); the value of f may be larger, for example, from 6 to 10, when the amount of the remaining stream and the number of catalyst beds are larger and/or the entry position of the remaining stream is larger.

According to the method of the present invention, the stream 1 obtained by the splitting operation is introduced into the catalyst bed layer 1, and the remaining stream is introduced into the catalyst bed layer located downstream of the catalyst bed layer 1. The relative proportions of the 1 st stream and the remainder stream are such as to inhibit the increase in the total pressure drop across the catalyst bed. According to the method of the present invention, the content of the residual stream is 5 to 50% by weight based on the feed to the 1 st catalyst bed, so that the increase in the total pressure drop of the catalyst bed can be suppressed more effectively. In general, the total amount of the remaining streams from the first splitting operation to the last splitting operation may be up to 50 wt%, such as 5 to 50 wt%, preferably 10 to 48 wt%, of the reaction feed, based on the total amount of the reaction feed. In the present invention, the reaction feed comprises the entire stream entering the catalyst bed.

According to the process of the invention, the remaining stream resulting from the splitting operation is passed to any catalyst bed located downstream of the 1 st catalyst bed.

In one embodiment, the remaining streams obtained from the first splitting operation are all fed into the same catalyst bed layer located at the downstream of the 1 st catalyst bed layer, and the value of f is preferably 2, that is, the feed of the 1 st catalyst bed layer is divided into the 1 st stream and the 2 nd stream, the 1 st stream enters the 1 st catalyst bed layer, and the 2 nd stream enters the same catalyst bed layer located at the downstream of the 1 st catalyst bed layer. This embodiment is particularly suitable for applications where the flow of the residual is low, the number of catalyst beds is low, or the amount of residual is low.

In another embodiment, the remaining stream from the first splitting operation is fed to a different catalyst bed located downstream of the 1 st catalyst bed, in which case f preferably has a value greater than 2. For example, the feed to the 1 st catalyst bed can be divided into a 1 st stream, a 2 nd stream, and a 3 rd stream, with the 1 st stream entering the 1 st catalyst bed, the 2 nd stream entering the 2 nd catalyst bed, and the 3 rd stream entering the 3 rd catalyst bed. This embodiment is particularly suitable for applications where the number of catalyst beds is large and the residual flow is large.

According to the method of the invention, the splitting operation can be carried out once or for a plurality of times, for example m times, m is an integer of more than 2, and the specific value can be determined according to the reactorThe total pressure drop set value of the catalyst bed layer is selected to control the total pressure drop of the catalyst bed layer within a preset range, and the following conditions are met: total pressure drop Δ P at a certain time t_tWith initial value of total pressure drop Δ P₀Has a ratio of Δ P_t/ΔP₀，1.1≤ΔP_t/ΔP₀Less than or equal to 5; preferably, 1.2. ltoreq. Δ P_t/ΔP₀Less than or equal to 3; more preferably, 1.2. ltoreq. Δ P_t/ΔP₀≤2.5。

When a plurality of times of splitting operations are carried out, for example, m times of splitting operations are carried out, the residual material flow obtained in the m-1 splitting operation and the residual material flow obtained in the m times of splitting operation can be sent to the same catalyst bed layer, or at least part of the residual material flow obtained in the m times of splitting operation can be sent to the catalyst bed layer positioned at the downstream of the catalyst bed layer into which the residual material flow obtained in the m-1 splitting operation enters.

As an embodiment of feeding the remaining streams from the m-1 th dividing operation and the m-th dividing operation to the same catalyst bed, taking the number of catalyst beds as 2 (i.e., n is 2), and dividing the feed of the 1 st catalyst bed into the 1 st stream and the 2 nd stream (i.e., f is 2), the dividing operation may be operated as follows: in the initial stage of reaction, reaction feed enters a 1 st catalyst bed layer and sequentially flows through the 1 st catalyst bed layer and a 2 nd catalyst bed layer, when the total pressure drop of the catalyst bed layers rises, the feed (namely, reaction feed) of the 1 st catalyst is divided into a 1 st material flow and a 2 nd material flow, the 1 st material flow enters the 1 st catalyst bed layer, the 2 nd material flow enters the 2 nd catalyst bed layer, the 1 st material flow and the 2 nd material flow and the feeding mode thereof are maintained until the total pressure drop of the catalyst bed layers rises again, the feed of the 1 st catalyst bed layer is divided into the 1 st material flow and the 2 nd material flow again, the 1 st material flow obtained by secondary division enters the 1 st catalyst bed layer, the 2 nd material flow obtained by secondary division and the 2 nd material flow obtained by primary division enter the 2 nd catalyst bed layer together, and the like until the feed is.

As an embodiment of feeding the remaining stream obtained by the m-1 th dividing operation and the remaining stream obtained by the m-th dividing operation to different catalyst beds, at least a part of the remaining stream obtained by the m-th dividing operation may be fed to a catalyst bed located downstream of the catalyst bed to which the remaining stream obtained by the m-1 th dividing operation is fed. For example: the rest material flow obtained by the m-1 time of the shunting operation respectively enters a 2 nd catalyst bed layer and a 3 rd catalyst bed layer, the rest material flow obtained by the m time of the shunting operation can enter the catalyst bed layer positioned at the downstream of the 3 rd catalyst bed layer, or part of the rest material flow obtained by the m time of the shunting operation can be sent to the 2 nd catalyst bed layer and/or the 3 rd catalyst bed layer, and the rest part is sent to the catalyst bed layer positioned at the downstream of the 3 rd catalyst bed layer.

When the first shunting operation is carried out, the feeding mode obtained by the shunting operation is continued until the total pressure drop of the catalyst bed layer reaches the set value of the reaction device. When the flow splitting operation is carried out for a plurality of times, the reaction feeding mode obtained by the m-1 time flow splitting operation is continued to the m time flow splitting operation.

According to the method of the invention, the 1 st catalyst bed layer to the n th catalyst bed layer can be arranged in the same reactor or different reactors, and part of the catalyst bed layers can be arranged in the same reactor and the rest of the catalyst bed layers can be arranged in different reactors. That is, the 1 st to nth catalyst beds may be provided in one reactor or may be provided in y reactors, and y is an integer in the interval [2, n ]. For the catalyst beds disposed in the same reactor, it is preferable to dispose the catalyst beds in the same reactor to be spatially adjacent from the viewpoint of convenience in operation and reduction in energy consumption. A liquid distributor may be provided between adjacent catalyst beds to provide a more uniform distribution of feed into the catalyst beds within the catalyst beds.

According to the process of the present invention, the temperature within the catalyst bed may be in the range of from 20 to 200 ℃, preferably from 25 to 180 ℃, more preferably from 30 to 120 ℃. The inlet pressure in the reactor with the catalyst bed may be in the range of from 0 to 3MPa, preferably from 0.1 to 2.5MPa, more preferably from 0.2 to 1MPa, expressed as gauge pressure. According to the method of the present invention, even if the temperature of the catalyst bed is low, for example, not higher than 60 ℃ (30-60 ℃), preferably not higher than 50 ℃ (e.g., 35-50 ℃), the selectivity for sulfone can be effectively improved when the catalyst contains the vanadium-titanium-silicon molecular sieve of the preferred embodiment described above.

According to the process of the present invention, the effluent of the nth catalyst bed, which contains the sulfone as a reaction product, may be separated (e.g., by distillation) in a conventional manner to yield the sulfone, optionally solvent, and unreacted sulfide, if any. The sulfone as product can be exported or sent to other purification units for further purification. The separated solvent and unreacted thioether may be recycled.

The present invention will be described in detail with reference to examples, but the scope of the present invention is not limited thereto.

In the following examples and comparative examples, the pressures are gauge pressures.

In the following examples and comparative examples, pore volume and pore size distribution were measured on a Micromeritics ASAP2405 static nitrogen adsorption apparatus; the molar composition of the molecular sieve was measured on a 3271E X-ray fluorescence spectrometer, japan chem electronics co; x-ray diffraction analysis (XRD) was performed on a Siemens D5005X-ray diffractometer.

In the following examples and comparative examples, the contents of the respective components in the obtained reaction liquid were analyzed by gas chromatography, and on the basis of which the thioether conversion and sulfone selectivity were calculated by the following formulas, respectively:

thioether conversion (%) × 100 [ (molar amount of added thioether-molar amount of unreacted thioether)/molar amount of added thioether ];

sulfone selectivity (%) × 100% in molar amount of sulfone produced by the reaction/(molar amount of added sulfide-molar amount of unreacted sulfide).

In the following examples and comparative examples, the activity of titanium silicalite molecular sieves was determined by the following method.

Mixing titanium-silicon molecular sieve with 36 wt% ammonia water (as NH)₃Calculated as H), 30 wt% of hydrogen peroxide (calculated as H)₂O₂Calculated), tert-butyl alcohol and cyclohexanone in a mass ratio of 1: 7.5: 10: 7.5: 10 stirring and reacting for 2h at 80 ℃ under atmospheric pressure, and filtering the reactantsAnalyzing the composition of the liquid phase by using a gas chromatography, calculating the conversion rate of cyclohexanone by using the following formula and using the conversion rate as the activity of the titanium silicalite molecular sieve,

conversion of cyclohexanone ═ molar amount of added cyclohexanone-molar amount of unreacted cyclohexanone)/molar amount of added cyclohexanone ] × 100%.

Preparative examples 1-12 were used to prepare molecular sieves.

Preparation of example 1

The preparation example adopts a hydrothermal crystallization method to prepare the titanium silicalite molecular sieve without vanadium.

Mixing ethyl orthosilicate, titanium isopropoxide and tetrapropylammonium hydroxide, adding a proper amount of distilled water, stirring and mixing, wherein the weight ratio of ethyl orthosilicate: titanium isopropoxide: tetrapropylammonium hydroxide: the molar ratio of water is 100: 3: 20: 2000, wherein the ethyl orthosilicate is SiO₂Calculated as TiO, titanium isopropoxide₂Counting; hydrolyzing at normal pressure and 60 deg.C for 1 hr, stirring at 75 deg.C for 3 hr, placing the mixed solution in a stainless steel sealed reaction kettle, and standing at 170 deg.C for 72 hr to obtain crystallized product mixture; the mixture was filtered, and the collected solid phase was washed with water and dried at 110 ℃ for 60 minutes to obtain a molecular sieve raw powder. Calcining the molecular sieve raw powder in an air atmosphere at 550 ℃ for 3 hours to obtain the titanium-silicon molecular sieve, and XRD analysis proves that the titanium-silicon molecular sieve is of an MFI structure, is a titanium-silicon molecular sieve TS-1, and has the property parameters listed in Table 1.

Preparation of example 2

The preparation example adopts a hydrothermal crystallization method to prepare the vanadium-titanium-silicon molecular sieve.

Mixing ethyl orthosilicate, ammonium metavanadate, titanium isopropoxide and tetrapropylammonium hydroxide, adding a proper amount of distilled water, and stirring and mixing, wherein the weight ratio of ethyl orthosilicate: titanium isopropoxide: ammonium metavanadate: tetrapropylammonium hydroxide: the molar ratio of water is 100: 3: 1: 20: 2000, wherein the ethyl orthosilicate is SiO₂Calculated as TiO, titanium isopropoxide₂Calculated as V for ammonium metavanadate₂O₅Counting; hydrolyzing at normal pressure and 60 deg.C for 1 hr, stirring at 75 deg.C for 3 hr, placing the mixture in a stainless steel sealed reaction kettle, and standing at 170 deg.CStanding for 72 hours to obtain a mixture of crystallized products; the mixture was filtered, and the collected solid phase was washed with water and dried at 110 ℃ for 60 minutes to obtain a molecular sieve raw powder. The vanadium-titanium-silicon molecular sieve is obtained by roasting the molecular sieve raw powder in the air atmosphere at 550 ℃ for 3 hours, the XRD crystal phase diagram of the molecular sieve is consistent with that of preparation example 1, the obtained molecular sieve has an MFI structure, and the property parameters of the molecular sieve are listed in Table 1.

Preparation of example 3

The preparation example adopts a hydrothermal crystallization method to prepare the vanadium-silicon molecular sieve.

Mixing ethyl orthosilicate, ammonium metavanadate and tetrapropylammonium hydroxide, adding a proper amount of distilled water, and stirring and mixing, wherein the weight ratio of ethyl orthosilicate: ammonium metavanadate: tetrapropylammonium hydroxide: the molar ratio of water is 100: 1: 20: 2000, wherein the ethyl orthosilicate is SiO₂Calculated as V for ammonium metavanadate₂O₅Counting; hydrolyzing at normal pressure and 60 deg.C for 1 hr, stirring at 75 deg.C for 3 hr, placing the mixed solution in a stainless steel sealed reaction kettle, and standing at 170 deg.C for 72 hr to obtain crystallized product mixture; the mixture was filtered, and the collected solid phase was washed with water and dried at 110 ℃ for 60 minutes to obtain a molecular sieve raw powder. The vanadium-silicon molecular sieve is obtained by roasting the molecular sieve raw powder in an air atmosphere at 550 ℃ for 3 hours, and the XRD crystal phase diagram of the vanadium-silicon molecular sieve is consistent with that of preparation example 1, which shows that the obtained molecular sieve has an MFI structure, and the property parameters of the molecular sieve are listed in Table 1.

Preparation of example 4

This preparation example prepares a vanadium titanium silicalite molecular sieve.

(1) Titanium silicalite molecular sieves (prepared by the same method as in preparation example 1) and 1mol/L hydrochloric acid aqueous solution were mixed and slurried at normal temperature (20 ℃) and normal pressure (1 atm), and then the mixed slurry was mixed and stirred at 80 ℃ for 12 hours, followed by solid-liquid separation and collection of solid-phase substances. Wherein, the titanium silicon molecular Sieve (SiO)₂Calculated as H) with HCl (in terms of H)⁺In terms of) is 100: 8.

(2) mixing ethyl orthosilicate as a silicon source, titanium sulfate as a titanium source and ammonium metavanadate as a vanadium source, and then mixing the obtained mixture with oxyhydrogenAnd (2) after mixing the sodium hydroxide aqueous solution, adding the solid-phase substance obtained in the step (1), uniformly mixing, placing the mixture in a high-pressure reaction kettle, and treating at 170 ℃ for 12 hours, wherein the titanium silicalite molecular sieve: silicon source: a titanium source: a vanadium source: alkali source: the molar ratio of water is 100: 10: 2: 1: 15: 250, titanium-silicon molecular sieve is SiO₂Calculated as OH, base^-Silicon source SiO₂The titanium source is calculated as TiO₂The vanadium source is measured as V₂O₅And (6) counting.

After the treatment was completed, the obtained reaction mixture was filtered, the solid phase was collected and washed with water, and then the solid phase was dried at 110 ℃ for 120 minutes and then calcined at 550 ℃ for 3 hours in an air atmosphere to obtain a vanadium-titanium-silicon molecular sieve, whose XRD crystallographic phase diagram was identical to that of preparation example 1, indicating that a molecular sieve having an MFI structure was obtained, and the property parameters of which are listed in table 1.

Preparation of example 5

This preparation example prepared a vanadium-titanium-silicon molecular sieve in the same manner as in preparation example 4, except that the titanium-silicon molecular sieve was prepared by calcining the discharging agent (fresh agent prepared in the same manner as in preparation example 1) of the cyclohexanone ammoximation reaction apparatus at 500 ℃ in an air atmosphere for 4 hours, the discharging agent having an activity of 45% and the discharging agent having an activity of 96% when fresh.

The XRD phase diagram of the obtained vanadium-titanium-silicon molecular sieve is consistent with that of preparation example 1, which shows that the molecular sieve with MFI structure is obtained, and the property parameters are listed in Table 1.

Preparation of example 6

The same titanium silicalite molecular sieves as in preparative example 5 were used in this preparative example.

(1) A solid-phase material was prepared in the same manner as in step (1) of preparation example 5.

(2) Mixing the solid-phase substance obtained in the step (1) with an ammonium metavanadate aqueous solution, wherein the molar ratio of the titanium silicalite molecular sieve to the ammonium metavanadate to the water is 10: 2: 20, titanium silicalite molecular sieve is SiO₂Calculated as V for ammonium metavanadate₂O₅Stirring for 3 hours at normal pressure and 50 DEG CThen, the mixture is filtered, the solid-phase substance is collected and washed by water, the solid-phase substance is dried for 60 minutes at 110 ℃, and then is roasted for 3 hours at 550 ℃ in an air atmosphere, so as to obtain the vanadium-loaded titanium-silicon molecular sieve.

Preparation of example 7

The titanium silicalite molecular sieve adopted in the preparation example is obtained by roasting a discharging agent (a fresh agent, which is prepared by the same method as the preparation example 1 and contains 1.5mol percent of titanium oxide) of a cyclohexanone ammoximation reaction device for 2 hours at 550 ℃ in an air atmosphere, wherein the activity of the discharging agent is 32 percent, and the activity of the discharging agent in the fresh state is 95 percent.

(1) Mixing and pulping the titanium-silicon molecular sieve and 8mol/L nitric acid aqueous solution at normal temperature (20 ℃) and normal pressure (1 standard atmospheric pressure), mixing and stirring the mixed slurry at 95 ℃ for 2 hours, carrying out solid-liquid separation, and collecting solid-phase substances. Wherein, the titanium silicon molecular Sieve (SiO)₂Meter) with HNO₃(with H)⁺In terms of) is 100: 12.

(2) mixing ethyl orthosilicate used as a silicon source, titanium tetrachloride used as a titanium source and sodium vanadate used as a vanadium source, then mixing the obtained mixture with a sodium hydroxide aqueous solution, adding the solid-phase substance obtained in the step (1), uniformly mixing, placing the mixture in a high-pressure reaction kettle, and treating at 140 ℃ for 18 hours, wherein the titanium-silicon molecular sieve: silicon source: a titanium source: a vanadium source: alkali source: the molar ratio of water is 100: 5: 1: 0.5: 7.5: 600 titanium silicalite molecular sieve with SiO₂Calculated as OH, base^-Silicon source SiO₂The titanium source is calculated as TiO₂The vanadium source is measured as V₂O₅And (6) counting.

After the treatment, the obtained reaction mixture was filtered, the solid phase was collected and washed with water, and then dried at 150 ℃ for 80 minutes, and then calcined at 480 ℃ for 6 hours in an air atmosphere to obtain a vanadium-titanium-silicon molecular sieve, the XRD crystallography of which is consistent with that of preparation example 1, indicating that a molecular sieve with MFI structure was obtained, and the property parameters of which are listed in table 1.

Preparation of example 8

Vanadium titanium silicalite molecular sieves were prepared in the same manner as in preparative example 7, except that the titanium silicalite molecular sieves used were fresh titanium silicalite molecular sieves forming the discharge agent in preparative example 7, to thereby obtain vanadium titanium silicalite molecular sieves having XRD crystallographic phase diagrams in accordance with preparative example 1, indicating that molecular sieves having MFI structures were obtained, the property parameters of which are listed in table 1.

Preparation of example 9

The titanium silicalite molecular sieve adopted in the preparation example is obtained by roasting a discharging agent (a fresh agent, which is prepared by the same method as the preparation example 1 and contains 4.6mol percent of titanium oxide) of a cyclohexanone ammoximation reaction device at 580 ℃ for 1.5 hours in an air atmosphere, wherein the activity of the discharging agent is 48 percent, and the activity of the discharging agent in the fresh state is 96 percent.

(1) Mixing and pulping the titanium silicalite molecular sieve and 15mol/L phosphoric acid aqueous solution at normal temperature (20 ℃) and normal pressure (1 standard atmospheric pressure), mixing and stirring the mixed pulp at 90 ℃ for 3 hours, carrying out solid-liquid separation, and collecting solid-phase substances. Wherein, the titanium silicon molecular Sieve (SiO)₂Meter) and H₃PO₄(with H)⁺In terms of) is 100: 6.

(2) mixing ethyl orthosilicate serving as a silicon source, tetra-n-propyl titanate serving as a titanium source and potassium metavanadate serving as a vanadium source, then mixing the obtained mixture with a sodium hydroxide aqueous solution, adding the solid-phase substance obtained in the step (1), uniformly mixing, placing the mixture in a high-pressure reaction kettle, and treating at 160 ℃ for 16 hours, wherein the titanium-silicon molecular sieve: silicon source: a titanium source: a vanadium source: alkali source: the molar ratio of water is 100: 21: 4.1: 2: 30: 800, titanium silicalite molecular sieve is SiO₂Calculated as OH, base^-Silicon source SiO₂The titanium source is calculated as TiO₂The vanadium source is measured as V₂O₅And (6) counting.

After the treatment, the obtained reaction mixture was filtered, the solid phase was collected and washed with water, and then the solid phase was dried at 160 ℃ for 70 minutes and then calcined at 520 ℃ in air atmosphere for 4 hours to obtain a vanadium-titanium-silicon molecular sieve, the XRD crystallography of which is consistent with that of preparation example 1, indicating that a molecular sieve with MFI structure was obtained, and the property parameters of which are listed in table 1.

Preparation of example 10

The same method as that used in preparation example 9 was used to prepare a vanadium titanium silicalite molecular sieve, except that the titanium silicalite molecular sieve used was the fresh titanium silicalite molecular sieve forming the discharge agent of preparation example 9, thereby obtaining a vanadium titanium silicalite molecular sieve, whose XRD crystal phase diagram was consistent with that of preparation example 1, indicating that a molecular sieve with MFI structure was obtained, and the property parameters of which are listed in table 1.

Preparation of example 11

The same method as that of the step (1) in the preparation example 9 is adopted to treat the titanium silicalite to prepare the vanadium-titanium silicalite, except that the solid-phase substance separated in the step (1) is dried at 160 ℃ for 70 minutes and then is roasted at 520 ℃ for 4 hours in the air atmosphere to obtain the vanadium-titanium silicalite, the XRD crystal phase diagram of the vanadium-titanium silicalite is consistent with that of the preparation example 1, which indicates that the obtained molecular sieve has an MFI structure, and the property parameters of the molecular sieve are listed in the table 1.

Preparation of example 12

A vanadium titanium silicalite molecular sieve was prepared in the same manner as in preparation example 9, except that instead of step (1), the titanium silicalite molecular sieve used as the starting material in step (1) was used in place of the solid phase material in step (2), to obtain a vanadium titanium silicalite molecular sieve having an XRD crystal phase diagram in accordance with preparation example 1, indicating that a molecular sieve having an MFI structure was obtained, and the property parameters thereof are listed in table 1.

TABLE 1

Sample source	Silicon: titanium: molar ratio of vanadium	C	D
				Preparation of example 1	100：3.1：0	<0.1	0.91
Preparation of example 2	100：2.8：0.9	<0.1	0.89
				Preparation of example 3	100：0：0.9	<0.1	0.92
Preparation of example 4	100：2.9：0.8	0.22	0.61
				Preparation of example 5	100：2.6：0.9	0.37	0.54
Preparation of example 6	100：2.6：0.9**	0.09	0.68
				Preparation of example 7	100：1.4：1.1	0.18	0.50
Preparation of example 8	100：1.6：1.0	0.13	0.64
				Preparation of example 9	100：4.3：0.8	0.47	0.56
Preparation of example 10	100：4.5：0.7	0.24	0.69
				Preparation of example 11	100：4.1：0.7	0.36	0.43
Preparation of example 12	100：4.6：0.8	0.12	0.71

*: the molar ratio of silicon, titanium and vanadium in the prepared molecular sieve is calculated by elements; when the molar ratio of silicon to titanium or vanadium is greater than 1000, titanium or vanadium is counted as 0.

**: is non-framework vanadium.

C＝X_1-1.8/X_0.4-0.9，X_0.4-0.9The ratio of the pore diameter of micropores in the range of 0.4-0.9nm in the molecular sieve to the distribution of the total pore diameter, X_1-1.8Is the proportion of the pore diameter of the micropores of the molecular sieve in the range of 1-1.8nm in the distribution quantity of the pore diameter of the total micropores.

D＝T_w/T_k，T_wIs the micropore volume of the molecular sieve, T_kIs the total pore volume of the molecular sieve.

Examples 1-15 are provided to illustrate the preparation of the sulfones of the present invention.

Example 1

This example used the titanium silicalite molecular sieve prepared in preparative example 1 as the catalyst.

Filling a catalyst in a fixed bed reactor to form catalyst beds, wherein the number of the catalyst beds is 2, taking the flow direction of feed in the catalyst beds as a reference, representing the upstream catalyst bed as a 1 st catalyst bed, representing the downstream catalyst bed as a 2 nd catalyst bed, wherein the 1 st catalyst bed and the 2 nd catalyst bed have the same diameter and the height-diameter ratio is 5, the 1 st catalyst bed and the 2 nd catalyst bed are adjacent in space, and a liquid distributor is arranged at the inlets of the 1 st catalyst bed and the 2 nd catalyst bed.

The reaction feed used in this example contained dimethyl sulfide, hydrogen peroxide (provided as 20 wt% hydrogen peroxide) as an oxidant, and methanol as a solvent, where the molar ratio of hydrogen peroxide to dimethyl sulfide was 2.5: 1, the mass ratio of methanol to dimethyl sulfide is 10: 1.

feeding reaction feed into the 1 st catalyst bed layer from the bottom of the fixed bed reactor, sequentially flowing through the 1 st catalyst bed layer and the 2 nd catalyst bed layer, and carrying out contact reaction with the catalyst filled in the catalyst bed layers. Wherein the temperature in the 1 st catalyst bed layer and the 2 nd catalyst bed layer is controlled to be 35 ℃, the weight hourly space velocity of dimethyl sulfide is 50h based on the total amount of the catalysts filled in the 1 st catalyst bed layer and the second catalyst bed layer^-1The inlet pressure of the reactor was 0.2MPa, and the initial value of the total pressure drop of the catalyst bed was Δ P₀Is 12 kPa.

In the reaction process, monitoring the total pressure drop of the catalyst bed layer, and when the total pressure drop of the catalyst bed layer reaches 25kPa, carrying out shunting operation:

the feeding of the 1 st catalyst bed layer is divided into a 1 st material flow and a 2 nd material flow, the content of the 2 nd material flow is 20 weight percent based on the total amount of reaction feeding, the 1 st material flow enters the 1 st catalyst bed layer from the bottom of the fixed bed reactor and sequentially flows through the 1 st catalyst bed layer and the 2 nd catalyst bed layer, and the 2 nd material flow enters the 2 nd catalyst bed layer. The split operation was performed 1 time in total, and the feed pattern formed by the split operation was maintained.

The reaction was continued for 900 hours, and at the end of the reaction, the total pressure drop across the catalyst bed was 36 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethyl sulfide conversion and dimethyl sulfone selectivity were calculated and the results are set forth in table 2.

Comparative example 1

Dimethyl sulfone was prepared by the same method as in example 1, except that no split operation was carried out during the reaction.

The reaction was continued for 400 hours, at the end of which the total pressure drop across the catalyst bed was 39 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethyl sulfide conversion and dimethyl sulfone selectivity were calculated and the results are set forth in table 2.

Example 2

Dimethyl sulfone was prepared by the same method as in example 1, except that the titanium silicalite molecular sieve of example 1 was replaced with the vanadium titanium silicalite molecular sieve of preparation example 2.

The reaction was continued for 690 hours, at the end of which the total pressure drop across the catalyst bed was 40 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethyl sulfide conversion and dimethyl sulfone selectivity were calculated and the results are set forth in table 2.

Example 3

Dimethyl sulfone was prepared by the same method as in example 1, except that the vanadium silicalite molecular sieve prepared in preparation example 3 was used instead of the titanium silicalite molecular sieve in example 1.

The reaction was continued for 630 hours with a total pressure drop of 38kPa at the end of the reaction in the catalyst bed. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethyl sulfide conversion and dimethyl sulfone selectivity were calculated and the results are set forth in table 2.

Example 4

Dimethyl sulfone was prepared by the same method as in example 1, except that the titanium silicalite molecular sieve of example 1 was replaced with the vanadium titanium silicalite molecular sieve of preparation example 4.

The reaction was continued for 780 hours, and at the end of the reaction, the total pressure drop across the catalyst bed was 37 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethyl sulfide conversion and dimethyl sulfone selectivity were calculated and the results are set forth in table 2.

Example 5

Dimethyl sulfone was prepared by the same method as in example 1, except that the titanium silicalite molecular sieve of example 1 was replaced with the vanadium titanium silicalite molecular sieve of preparation example 5.

The reaction was continued for 890 hours, at the end of which the total pressure drop of the catalyst bed was 35 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethyl sulfide conversion and dimethyl sulfone selectivity were calculated and the results are set forth in table 2.

Example 6

Dimethyl sulfone was prepared by the same method as in example 1, except that the catalyst was the vanadium-supported titanium silicalite prepared in preparation example 6.

The reaction was continued for 520 hours, and at the end of the reaction, the total pressure drop across the catalyst bed was 41 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethyl sulfide conversion and dimethyl sulfone selectivity were calculated and the results are set forth in table 2.

Example 7

Dimethyl sulfone was prepared in the same manner as in example 1, except that the operation of dividing the flow was carried out a plurality of times in the following manner:

monitoring the total pressure drop of the catalyst bed in the reaction process, wherein the total pressure drop delta P is measured at a certain time t_tWith initial value of total pressure drop Δ P₀Ratio of (delta P)_t/ΔP₀Is 1.2. ltoreq. DELTA.P_t/ΔP₀When the flow rate is less than or equal to 2, carrying out flow dividing operation:

the feeding of the 1 st catalyst bed layer is divided into a 1 st material flow and a 2 nd material flow, wherein the 1 st material flow enters the 1 st catalyst bed layer from the bottom of the fixed bed reactor and sequentially flows through the 1 st catalyst bed layer and the 2 nd catalyst bed layer, and the 2 nd material flow enters the 2 nd catalyst bed layer.

And (3) keeping the feeding mode formed by each shunting operation till the next shunting operation, shunting the feeding of the 1 st catalyst bed layer formed by the previous shunting operation by the next shunting operation, wherein the feeding of the 2 nd catalyst bed layer is the whole 2 nd material flow obtained by the current shunting operation and each shunting operation before the current shunting operation. The 2 nd stream separated in each splitting operation accounts for 5 to 10% by weight of the 1 st stream obtained in the preceding splitting operation adjacent to the splitting operation.

The reaction was continued for 1080 hours, and at the end of the reaction, the total pressure drop across the catalyst bed was 17 kPa. By the splitting operation, the entire 2 nd stream (i.e., the feed to the 2 nd catalyst bed after the last splitting operation) split from the reaction feed accounted for 42 wt% of the reaction feed to the 1 st catalyst bed at the beginning of the reaction.

The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethyl sulfide conversion and dimethyl sulfone selectivity were calculated and the results are set forth in table 2.

TABLE 2

Example 8

This example used the vanadium titanium silicalite molecular sieve prepared in preparative example 7 as the catalyst.

Filling a catalyst in a fixed bed reactor to form catalyst beds, wherein the number of the catalyst beds is 2, taking the flow direction of feed in the catalyst beds as a reference, representing the upstream catalyst bed as a 1 st catalyst bed, representing the downstream catalyst bed as a 2 nd catalyst bed, wherein the 1 st catalyst bed and the 2 nd catalyst bed have the same diameter, the height-diameter ratio is 8, the 1 st catalyst bed and the 2 nd catalyst bed are adjacent in space, and a liquid distributor is arranged at the inlets of the 1 st catalyst bed and the 2 nd catalyst bed.

The reaction feed employed in this example contained dimethyl sulfide, t-butyl hydroperoxide as the oxidant (provided as a 23 wt% acetonitrile solution) and acetonitrile as the solvent, wherein the molar ratio of t-butyl hydroperoxide to dimethyl sulfide was 2.2: 1, the mass ratio of acetonitrile to dimethyl sulfide is 15: 1.

feeding reaction feed into the 1 st catalyst bed layer from the bottom of the fixed bed reactor, sequentially flowing through the 1 st catalyst bed layer and the 2 nd catalyst bed layer, and carrying out contact reaction with the catalyst filled in the catalyst bed layers. Wherein the temperature in the 1 st catalyst bed layer and the 2 nd catalyst bed layer is controlled to be 45 ℃, and the weight hourly space velocity of dimethyl sulfide is 30h based on the total amount of the catalysts filled in the 1 st catalyst bed layer and the second catalyst bed layer^-1The inlet pressure of the reactor was 0.25MPa, and the initial value of the total pressure drop of the catalyst bed was Δ P₀Is 14 kPa.

Monitoring the total pressure drop of the catalyst bed in the reaction process, wherein the total pressure drop delta P is measured at a certain time t_tWith initial value of total pressure drop Δ P₀Ratio of (delta P)_t/ΔP₀Is 1.2. ltoreq. DELTA.P_t/ΔP₀When the flow is less than or equal to 1.8, carrying out flow dividing operation: the feeding of the 1 st catalyst bed layer is divided into a 1 st material flow and a 2 nd material flow, wherein the 1 st material flow enters the 1 st catalyst bed layer from the bottom of the fixed bed reactor and sequentially flows through the 1 st catalyst bed layer and the 2 nd catalyst bed layer, and the 2 nd material flow enters the 2 nd catalyst bed layer.

And (3) keeping the feeding mode formed by each shunting operation till the next shunting operation, shunting the feeding of the 1 st catalyst bed layer formed by the previous shunting operation by the next shunting operation, wherein the feeding of the 2 nd catalyst bed layer is the whole 2 nd material flow obtained by the current shunting operation and each shunting operation before the current shunting operation. The 2 nd stream separated in each splitting operation accounts for 5 to 15 wt% of the 1 st stream obtained in the previous splitting operation adjacent to the splitting operation.

The reaction was continued for 1150 hours, and at the end of the reaction, the total pressure drop across the catalyst bed was 21 kPa. By the splitting operation, the entire 2 nd stream (i.e., the feed to the 2 nd catalyst bed after the last splitting operation) split from the reaction feed accounted for 48 wt% of the reaction feed to the 1 st catalyst bed at the beginning of the reaction.

During the course of the reaction, the composition of the reaction product stream output from the fixed bed reactor was continuously monitored and the dimethyl sulfide conversion and dimethyl sulfone selectivity were calculated, with the results set forth in table 3.

Comparative example 2

Dimethyl sulfone was prepared by the same method as in example 8, except that no split operation was performed.

The reaction was continued for 420 hours, and at the end of the reaction, the total pressure drop across the catalyst bed was 41 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethyl sulfide conversion and dimethyl sulfone selectivity were calculated and the results are set forth in table 3.

Example 9

Dimethyl sulfone was prepared by the same method as in example 8, except that the catalyst was the vanadium titanium silicalite molecular sieve prepared by preparation example 8.

The reaction was continued for 990 hours, and at the end of the reaction, the total pressure drop of the catalyst bed was 23 kPa. By the splitting operation, the entire 2 nd stream (i.e., the feed to the 2 nd catalyst bed after the last splitting operation) split from the reaction feed accounted for 49 wt% of the reaction feed to the 1 st catalyst bed at the beginning of the reaction.

TABLE 3

Example 10

This example used the vanadium titanium silicalite molecular sieve prepared in preparative example 9 as the catalyst.

Filling a catalyst in a fixed bed reactor to form catalyst beds, wherein the number of the catalyst beds is 2, taking the flow direction of feed in the catalyst beds as a reference, representing the upstream catalyst bed as a 1 st catalyst bed, representing the downstream catalyst bed as a 2 nd catalyst bed, wherein the 1 st catalyst bed and the 2 nd catalyst bed have the same diameter and the height-diameter ratio of 4, the 1 st catalyst bed and the 2 nd catalyst bed are adjacent in space, and a liquid distributor is arranged at the inlets of the 1 st catalyst bed and the 2 nd catalyst bed.

The reaction feed employed in this example contained thiobenzyl ether, peroxypropionic acid as the oxidant (provided as a 30 wt.% solution in t-butanol), and t-butanol as the solvent, wherein the molar ratio of peroxypropionic acid to thiobenzyl ether was 2.3: 1, the mass ratio of the tertiary butanol to the thioanisole is 30: 1.

feeding reaction feed into the 1 st catalyst bed layer from the bottom of the fixed bed reactor, sequentially flowing through the 1 st catalyst bed layer and the 2 nd catalyst bed layer, and carrying out contact reaction with the catalyst filled in the catalyst bed layers. Wherein the temperature in the 1 st catalyst bed layer and the 2 nd catalyst bed layer is controlled to be 50 ℃, and the weight hourly space velocity of the dimethyl benzene sulfide is 18h based on the total amount of the catalysts filled in the 1 st catalyst bed layer and the second catalyst bed layer^-1The inlet pressure of the reactor is 1MPa, and the initial value delta P of the total pressure drop of the catalyst bed layer₀Is 10 kPa.

In the reaction process, monitoring the total pressure drop of the catalyst bed layer, and when the total pressure drop of the catalyst bed layer reaches 20kPa, carrying out shunting operation: the feeding of the 1 st catalyst bed layer is divided into a 1 st material flow and a 2 nd material flow, the content of the 2 nd material flow is 30 weight percent based on the total amount of reaction feeding, the 1 st material flow enters the 1 st catalyst bed layer from the bottom of the fixed bed reactor and sequentially flows through the 1 st catalyst bed layer and the 2 nd catalyst bed layer, and the 2 nd material flow enters the 2 nd catalyst bed layer. The split operation was performed 1 time in total, and the feed pattern formed by the split operation was maintained.

The reaction was continued for 780 hours, and at the end of the reaction, the total pressure drop across the catalyst bed was 28 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethylsulfide conversion and the benzylsulfone selectivity were calculated and the results are set forth in table 4.

Comparative example 3

Dimethyl sulfone was prepared by the same method as in example 10, except that no split operation was performed.

The reaction was continued for 340 hours, and at the end of the reaction, the total pressure drop across the catalyst bed was 29 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethylsulfide conversion and the benzylsulfone selectivity were calculated and the results are set forth in table 4.

Example 11

Benzyl sulfone was prepared by the same method as example 10, except that the catalyst was the vanadium titanium silicalite molecular sieve prepared in preparation example 10. The reaction was continued for 730 hours, and at the end of the reaction, the total pressure drop across the catalyst bed was 29 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethylsulfide conversion and the benzylsulfone selectivity were calculated and the results are set forth in table 4.

Example 12

Benzyl sulfone was prepared by the same method as example 10 except that the catalyst was the vanadium titanium silicalite molecular sieve prepared in preparation example 11.

The reaction was continued for 750 hours, at the end of which the total pressure drop across the catalyst bed was 28 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethylsulfide conversion and the benzylsulfone selectivity were calculated and the results are set forth in table 4.

Example 13

Benzyl sulfone was prepared by the same method as example 10 except that the catalyst was the vanadium titanium silicalite molecular sieve prepared in preparation example 12.

The reaction was continued for 490 hours, at the end of which the total pressure drop across the catalyst bed was 27 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethylsulfide conversion and the benzylsulfone selectivity were calculated and the results are set forth in table 4.

Example 14

Benzyl sulfone was prepared by the same method as example 10, except that the catalyst was the titanium silicalite prepared in preparation example 1.

The reaction was continued for 820 hours, and at the end of the reaction, the total pressure drop across the catalyst bed was 27 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethylsulfide conversion and the benzylsulfone selectivity were calculated and the results are set forth in table 4.

Example 15

Benzyl sulfone was prepared by the same method as example 10 except that the catalyst was the vanadium silicalite molecular sieve prepared in preparation example 3.

The reaction was continued for 710 hours, at the end of which the total pressure drop across the catalyst bed was 27 kPa. The composition of the reaction product stream output from the fixed bed reactor was continuously monitored during the course of the reaction and the dimethylsulfide conversion and the benzylsulfone selectivity were calculated and the results are set forth in table 4.

TABLE 4

The results of examples 1-15 demonstrate that the method of the present invention, when used to oxidize thioethers to sulfones, effectively suppresses the pressure drop increase of the catalyst bed, thereby effectively reducing the energy consumption for operation, extending the stable operation time of the reactor, and improving the safety of the operation of the apparatus.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A process for the preparation of a sulfone, which process comprises:

2. The method according to claim 1, wherein the splitting operation is performed once or m times, m being an integer of 2 or more.

3. The process according to claim 2, wherein the remaining stream from the m-1 splitting operation and the remaining stream from the m-splitting operation are fed to the same catalyst bed, or at least a part of the remaining stream from the m-splitting operation is fed to a catalyst bed located downstream of the catalyst bed to which the remaining stream from the m-1 splitting operation is fed.

4. A process according to claim 2 or claim 3, wherein the residual stream is present in an amount of from 5 to 50 wt% based on the feed to the 1 st catalyst bed.

5. The method according to any one of claims 1 to 3, wherein the splitting operation is performed when the total pressure drop of the catalyst bed satisfies the following conditions: total pressure drop Δ P at a certain time t_tWith initial value of total pressure drop Δ P₀Ratio of (delta P)_t/ΔP₀Is 1.1. ltoreq. DELTA.P_t/ΔP₀≤5。

6. The method of claim 5, wherein 1.2 ≦ Δ P_t/ΔP₀≤3。

7. The method of claim 6, wherein 1.2 ≦ Δ P_t/ΔP₀≤2.5。

8. The method of claim 5, wherein Δ P₀Not higher than 100 kPa.

9. The method of claim 8, wherein Δ Ρ₀5-50 kPa.

10. The method of claim 9, wherein Δ Ρ₀8-30 kPa.

11. The method of claim 10, wherein Δ Ρ₀Is 10-25 kPa.

12. A process according to any one of claims 1-3, wherein the 1 st to nth catalyst beds are arranged in one reactor or in y reactors, y being an integer in the interval [2, n ].

13. A process according to claim 12, wherein catalyst beds located within the same reactor are spatially contiguous.

14. The method of claim 1, wherein the molecular sieve is one or more selected from the group consisting of a titanium silicalite molecular sieve, a vanadium silicalite molecular sieve, and a vanadium titanium silicalite molecular sieve.

15. The method of claim 14, wherein the molecular sieve is a vanadium titanium silicalite molecular sieve satisfying X_1-1.8/X_0.4-0.9＝C，0.05<C<0.5，X_0.4-0.9The ratio of the pore diameter of micropores in the range of 0.4-0.9nm in the molecular sieve to the distribution of the total pore diameter, X_1-1.8Is the proportion of the pore diameter of the micropores of the molecular sieve in the range of 1-1.8nm in the distribution quantity of the pore diameter of the total micropores.

16. The method of claim 15, wherein 0.1 ≦ C ≦ 0.48.

17. The method of claim 14, wherein the vanadium titanium silicalite molecular sieve satisfies T_w/T_k＝D，0.3<D<0.7 of, wherein T_wIs the micropore volume of the molecular sieve, T_kIs the total pore volume of the molecular sieve.

18. The method of claim 17, wherein 0.4 ≦ D ≦ 0.6.

19. The method of claim 18, wherein 0.5 ≦ D ≦ 0.6.

20. The process of any one of claims 15 to 19, wherein the vanadium titanium silicalite molecular sieve has an elemental silicon: titanium element: the molar ratio of the vanadium element is 100: 0.5-10: 0.01-5.

21. The method of claim 20, wherein in the vanadium titanium silicalite molecular sieve, elemental silicon: titanium element: the molar ratio of the vanadium element is 100: 1-8: 0.2-2.5.

22. The method of claim 21, wherein in the vanadium titanium silicalite molecular sieve, elemental silicon: titanium element: the molar ratio of the vanadium element is 100: 1.2-6: 0.5-2.

23. The process of any one of claims 15 to 19, wherein the vanadium titanium silicalite molecular sieve is prepared using a process comprising:

(1) contacting a titanium silicalite molecular sieve with acid liquor at the temperature of 40-200 ℃, and separating a solid phase from a mixture obtained by the contact;

24. The process of claim 23, wherein in step (1), the titanium silicalite molecular sieves are contacted with the acid solution at a temperature of from 50 to 180 ℃.

25. The process of claim 24, wherein in step (1), the titanium silicalite molecular sieves are contacted with the acid solution at a temperature of 60-180 ℃.

26. The process of claim 25, wherein in step (1), the titanium silicalite molecular sieves are contacted with the acid solution at a temperature of 80-100 ℃.

27. The method of claim 23, wherein in step (1), the ratio of titanium silicalite molecular sieve: the molar ratio of the acids is 100: 0.005-50, the titanium silicalite molecular sieve is SiO₂In terms of H, the acid is⁺And (6) counting.

28. According to the claimsThe method of claim 27, wherein in step (1), the ratio of titanium silicalite: the molar ratio of the acids is 100: 0.1-30, the titanium silicalite molecular sieve is SiO₂In terms of H, the acid is⁺And (6) counting.

29. The process of claim 28, wherein in step (1), the ratio of titanium silicalite: the molar ratio of the acids is 100: 2-15, the titanium silicalite molecular sieve is made of SiO₂In terms of H, the acid is⁺And (6) counting.

30. The method of claim 23, wherein in step (1), the acid is HCl, H₂SO₄、HNO₃、CH₃COOH、HClO₄、H₃PO₄One or more than two of peroxyacetic acid and peroxypropionic acid.

31. The method of claim 23, wherein in step (1), the duration of the contacting is 0.5-36 hours.

32. The method of claim 31, wherein in step (1), the duration of the contacting is 1-24 hours.

33. The method of claim 32, wherein in step (1), the duration of the contacting is 1-18 hours.

34. The method of claim 33, wherein in step (1), the duration of the contacting is 2-12 hours.

35. The method of claim 23, wherein in step (2), the solid phase separated in step (1): silicon source: a titanium source: a vanadium source: the molar ratio of the alkali source is 100: 3-40: 0.1-8: 0.1-10: 0.5-50, the solid phase separated in step (1) and the silicon source are SiO₂The titanium source is calculated as TiO₂The vanadium source is counted as V₂O₅The alkali source is calculated as N or OH^-And (6) counting.

36. The method of claim 35, wherein in step (2), the solid phase separated in step (1): silicon source: a titanium source: a vanadium source: the molar ratio of the alkali source is 100: 5-30: 0.2-5: 0.3-5: 1-40, the solid phase separated in the step (1) and the silicon source are SiO₂The titanium source is calculated as TiO₂The vanadium source is counted as V₂O₅The alkali source is calculated as N or OH^-And (6) counting.

37. The method as claimed in claim 23, wherein the hydrothermal treatment in step (2) is carried out at a temperature of 100 ℃ and 200 ℃.

38. The method as claimed in claim 37, wherein the hydrothermal treatment in step (2) is carried out at a temperature of 120-180 ℃.

39. The process as claimed in claim 38, wherein the hydrothermal treatment in step (2) is carried out at a temperature of 130-170 ℃.

40. The method according to claim 23, wherein in step (2), the duration of the hydrothermal treatment is 0.5-96 hours.

41. The method according to claim 40, wherein in step (2), the duration of the hydrothermal treatment is 6-72 hours.

42. The method according to claim 41, wherein in step (2), the duration of the hydrothermal treatment is 8-56 hours.

43. The process according to claim 42, wherein in step (2), the duration of the hydrothermal treatment is 12-24 hours.

44. The method of claim 23, wherein in step (2), the solid phase separated in step (1): molar ratio of waterIs 100: 20-1000, the solid phase separated in step (1) is SiO₂And (6) counting.

45. The method of claim 44, wherein in step (2), the solid phase separated in step (1): the molar ratio of water is 100: 50-950, separating the solid phase obtained in step (1) with SiO₂And (6) counting.

46. The method of claim 45, wherein in step (2), the solid phase separated in step (1): the molar ratio of water is 100: 100-900, the solid phase separated in step (1) is SiO₂And (6) counting.

47. The method of claim 46, wherein in step (2), the solid phase separated in step (1): the molar ratio of water is 100: 200 ℃ 800. the solid phase separated in step (1) is SiO₂And (6) counting.

48. The method according to claim 23, wherein the alkali source is one or more selected from the group consisting of ammonia, an alkali whose cation is an alkali metal, an alkali whose cation is an alkaline earth metal, urea, an amine, an alcohol amine, and a quaternary ammonium base;

the silicon source is one or more than two selected from organic silicon sources;

the titanium source is one or more than two of inorganic titanium salt and organic titanate;

the vanadium source is one or more than two of vanadium oxide, vanadate and vanadium salt.

49. The method according to claim 23, wherein the alkali source is one or more selected from the group consisting of ammonia, an alkali whose cation is an alkali metal, an alkali whose cation is an alkaline earth metal, urea, an amine, an alcohol amine, and a quaternary ammonium base;

the vanadium source is one or more than two of vanadium oxide, vanadium halide and vanadium acid.

50. The method according to claim 23, wherein the alkali source is one or more selected from the group consisting of ammonia, an alkali whose cation is an alkali metal, an alkali whose cation is an alkaline earth metal, urea, an amine, an alcohol amine, and a quaternary ammonium base;

the vanadium source is one or more than two of vanadium oxide, vanadate and vanadate.

51. The method according to claim 23, wherein the alkali source is one or more selected from the group consisting of ammonia, an alkali whose cation is an alkali metal, an alkali whose cation is an alkaline earth metal, urea, an amine, an alcohol amine, and a quaternary ammonium base;

the vanadium source is one or more than two of vanadium oxide, orthovanadate, pyrovanadate and vanadium salt.

52. The method according to claim 23, wherein the alkali source is one or more selected from the group consisting of ammonia, an alkali whose cation is an alkali metal, an alkali whose cation is an alkaline earth metal, urea, an amine, an alcohol amine, and a quaternary ammonium base;

the vanadium source is one or more than two of vanadium oxide, vanadium halide, orthovanadate and pyrovanadate.

53. The method according to claim 23, wherein the alkali source is one or more selected from the group consisting of ammonia, an alkali whose cation is an alkali metal, an alkali whose cation is an alkaline earth metal, urea, an amine, an alcohol amine, and a quaternary ammonium base;

the vanadium source is one or more than two of vanadium oxide, orthovanadate, pyrovanadate and vanadate.

54. The process of claim 23, wherein the titanium silicalite molecular sieve is a discharge from an ammoximation reaction apparatus.

55. The process of claim 54, wherein the titanium silicalite molecular sieve is the discharge agent of a cyclohexanone ammoximation reaction apparatus.

56. The method of claim 54, wherein the activity of the discharging agent is 5-95% of the activity of the discharging agent when fresh.

57. The method of claim 56, wherein the activity of the discharging agent is 10-90% of its activity when fresh.

58. The method of claim 57, wherein the activity of the discharging agent is less than 60% of its activity when fresh.

59. The method of claim 58, wherein the unloading agent has an activity of 30-55% of its activity when fresh.

60. The method of claim 59, wherein the activity of the discharging agent is 35-50% of its activity when fresh.

61. The method of claim 23, wherein the titanium silicalite molecular sieve is a titanium silicalite molecular sieve having an MFI structure.

62. The method of claim 61, wherein the titanium silicalite molecular sieve is TS-1.

63. The process according to claim 1, wherein the molar ratio between the oxidizing agent and the thioether is from 2.1 to 5: 1.

64. the method of claim 63, wherein the molar ratio of the oxidizing agent to the thioether is from 2.2-3: 1.

65. the method of any one of claims 1, 63, and 64, wherein the oxidizing agent is a peroxide.

66. The method of claim 65, wherein the oxidizing agent is one or more of hydrogen peroxide, t-butyl hydroperoxide, ethylbenzene hydroperoxide, cumene hydroperoxide, cyclohexyl hydroperoxide, peroxyacetic acid, and peroxypropionic acid.

67. The method of any one of claims 1-3, 14-19, 63, and 64, wherein the oxidation reaction conditions comprise: the temperature is 20-200 ℃; the inlet pressure of the reactor with the catalyst bed is 0-3MPa, said pressure being the gauge pressure.

68. The method of claim 67, wherein the oxidation reaction conditions comprise: the temperature is 30-120 ℃; the inlet pressure of the reactor with the catalyst bed is 0.1-2.5MPa, said pressure being the gauge pressure.

69. The method of claim 68, wherein the oxidation reaction conditions comprise: the temperature is not higher than 60 ℃.

70. The method of claim 69, wherein the oxidation reaction conditions comprise: the temperature is not higher than 50 ℃.

71. The method of any one of claims 1-3, 14-19, 63, and 64, wherein the sulfide is dimethyl sulfide and/or benzyl sulfide.