Preparation method for vinylene carbonate

Abstract

Disclosed in the present invention is a preparation method for vinylene carbonate. Specifically, the preparation method of the present invention comprises the following steps: introducing a material containing chloroethylene carbonate into a reaction bed layer containing a catalyst to perform a contact reaction, so as to obtain vinylene carbonate, wherein the catalyst is prepared by means of the following method: performing forming by using a catalyst raw material, then optionally calcining same, and then cooling same, so as to obtain catalyst particles. The preparation method of the present invention has a low cost, is easy to operate, has a high conversion rate and a high yield and is beneficial to industrial production.

Description

A kind of preparation method of vinylene carbonate Technical Field

[0001] The present invention relates to the field of organic synthesis, and in particular to a method for preparing vinylene carbonate. Background Art

[0002] As we all know, vinylene carbonate (VC) can be used to produce chemicals, pharmaceutical products and crop protection agents, and is also widely used in the production of polymers, coatings and battery dielectrics.

[0003] In the prior art, German Patent DE 1135452 C2 discloses a method for catalyzing HCl elimination reaction of chloroethylene carbonate to produce vinylene carbonate using cadmium chloride supported on an inert carrier as a catalyst.

[0004] Disclose a kind of zinc chloride that is loaded on inert carrier as catalyzer, and in the catalytic bed of complete mixing stirring, carry out the HCl elimination reaction of ethylene chlorocarbonate.In this method, adopt fluidized bed reaction device to react, thereby guarantee the abundant contact of material and catalyzer, yet the reactor of such reaction is complicated, and product separation cost and device cost are all higher.Fixed-bed reactor (claiming packed bed reactor again) device cost is lower, is therefore more suitable for the industrialized production of vinylene carbonate, yet, the catalyzer that such reaction adopts in prior art is powdered, if insert fixed-bed reaction device and react, then easily cause the problems such as device blocking, affect device life-span, and adopt solid phase carrier to carry out load for catalyzer, then easily affect the contact of material and catalyzer, and then affect the efficient of reaction.

[0005] Chinese patent CN108997301 A also discloses a method for preparing vinylene carbonate, which uses triethylamine to react with halogenated vinyl carbonate to remove hydrogen chloride and prepare the target product. However, according to Chinese patent CN114797957A, such a process causes the product vinylene carbonate generated by the reaction to mix with triethylamine hydrochloride to form a black, viscous substance that is difficult to separate. The target product vinylene carbonate is then wrapped in this black, viscous substance, which is unfavorable for subsequent separation. In addition, an equivalent amount of triethylamine is required, resulting in high production costs. This technical solution is only applicable to batch production and cannot be produced continuously. Furthermore, this reaction is a liquid-phase reaction, requiring a large amount of solvent, which produces a large amount of three wastes during the production process and is not environmentally friendly enough.

[0006] In summary, there is an urgent need in the art to develop a low-cost, high-efficiency method for industrial production of vinylene carbonate.

[0007] Summary of the Invention

[0008] The present invention is made to solve the above problems and aims to provide a method for efficiently producing vinylene carbonate using a fixed bed or fluidized bed process.

[0009] An object of the present invention is to provide a catalyst which does not require a supporting material and is suitable for a vinylene carbonate fixed bed production process.

[0010] Another object of the present invention is to provide a process for preparing vinylene carbonate that can operate stably for a longer period of time without regenerating the catalyst.

[0011] A first aspect of the present invention provides a method for preparing vinylene carbonate, comprising the following steps: passing a material containing chloroethylene carbonate into a reaction bed containing a catalyst to carry out a contact reaction, thereby obtaining vinylene carbonate;

[0012] The catalyst is prepared by the following method: forming a catalyst raw material, then optionally calcining it, and then cooling it to obtain catalyst particles; preferably, the reaction temperature is 100-400°C.

[0013] In another preferred embodiment, the contact time is 0.5-120s.

[0014] In another preferred embodiment, the reaction temperature is 300-400°C.

[0015] In another preferred embodiment, the molding comprises: powdering the catalyst raw materials, fully mixing them, and then extruding them into molds.

[0016] In a preferred embodiment, the calcination comprises: calcining at 90-150° C. for 12-48 hours, and then calcining at 450-550° C. for 5-15 hours.

[0017] In a preferred embodiment, the reaction is carried out in a reactor filled with a bed of catalyst particles.

[0018] In a preferred embodiment, the particle size of the catalyst is 1 mm-5 mm, preferably 2 mm-4 mm.

[0019] In a preferred embodiment, the inner diameter of the cavity in the reactor for filling the catalyst particle bed is 20 mm to 30 mm, and the filling amount of the catalyst is 250 to 350 mL.

[0020] In another preferred embodiment, the specific surface area of ​​the catalyst is ≥200m 2 / g, preferably, the specific surface area of ​​the catalyst is 200m 2 / g-1000m 2 / g.

[0021] In a preferred embodiment, the catalyst is prepared by the following method: forming a catalyst raw material, then calcining at 100-150°C for 20-36 hours, calcining at 450-550°C for 8-12 hours, and then cooling to obtain catalyst particles.

[0022] In a preferred embodiment, the catalyst raw material includes a catalyst selected from Group A; or the catalyst raw material includes a catalyst selected from Group A and a catalyst selected from Group B;

[0023] Group A: Group IIA oxides, Group IIA metal sulfates, Group IB metals, Group IB metal chlorides, Group IB metal oxides, Group IIIA metal chlorides, Group IIIB metal oxides, Group IIIA metal oxides, Group VB metal oxides, VIB metal chlorides, Group VIIB metal oxides, Group VIII metals, Group VIII oxides, Group VIII metal chlorides, or combinations thereof;

[0024] Group B: oxides of Group IIIA elements, simple substances of Group IVA elements, oxides of Group IVA elements, Group IVB metal oxides, Group VIIB metal oxides, or combinations thereof.

[0025] In a preferred embodiment, the catalyst raw material includes a catalyst selected from Group A; or the catalyst raw material includes a catalyst selected from Group A and a catalyst selected from Group B;

[0026] Group A: ferroferric oxide, magnesium oxide, copper chloride, silver, gallium chloride, gallium oxide, manganese oxide, zinc oxide, indium oxide, cobalt oxide, ferrous oxide, ruthenium, cerium dioxide, chromium chloride, calcium sulfate, palladium oxide, palladium dichloride, nickel oxide, manganese dioxide, vanadium pentoxide, or a combination thereof;

[0027] Group B: titanium dioxide, manganese dioxide, aluminum oxide (preferably gamma-alumina), silicon dioxide, activated carbon, zirconium oxide, or a combination thereof.

[0028] In a preferred embodiment, the catalyst raw material includes a catalyst selected from Group A; or the catalyst raw material includes a catalyst selected from Group A and a catalyst selected from Group B;

[0029] Group A: ferroferric oxide, magnesium oxide, copper chloride, silver, gallium chloride, gallium oxide, manganese oxide, zinc oxide, indium oxide, cobalt oxide, ferrous oxide, ruthenium, cerium dioxide, or a combination thereof;

[0030] Group B: titanium dioxide, manganese dioxide, aluminum oxide (preferably gamma-alumina), silicon dioxide, activated carbon, zirconium oxide, or a combination thereof.

[0031] In a preferred embodiment, the gaseous or liquid chloroethylene carbonate is not stirred during the contacting process with the catalyst.

[0032] In a preferred embodiment, the material containing ethylene chlorocarbonate is formed by the following method: a carrier gas preheated to 300°C-450°C and ethylene chlorocarbonate are introduced into a vaporizer preheated to 300°C-450°C, the ethylene chlorocarbonate is vaporized and mixed with the carrier gas, thereby forming a material containing ethylene chlorocarbonate.

[0033] In a preferred embodiment, the carrier gas is selected from the group consisting of argon, helium, neon, nitrogen, carbon monoxide, carbon dioxide, hydrogen chloride gas, water vapor, or a combination thereof.

[0034] In a preferred embodiment, the material containing ethylene chlorocarbonate is formed by the following method: ethylene chlorocarbonate is introduced into a vaporizer having an internal pressure of 100Pa-10000Pa and preheated to 300°C-450°C, so that the ethylene chlorocarbonate is vaporized, thereby forming a material containing ethylene chlorocarbonate.

[0035] In another preferred embodiment, the material containing ethylene chlorocarbonate is formed by the following method: ethylene chlorocarbonate is introduced into a vaporizer having an internal pressure of 700Pa-1000Pa and preheated to 300°C-450°C, so that the ethylene chlorocarbonate is vaporized, thereby forming a material containing ethylene chlorocarbonate.

[0036] In a preferred embodiment, the method further comprises the following steps: passing the product gas stream into a condenser for condensation, thereby obtaining crude vinylene carbonate; preferably, the method further comprises the following steps: distilling the crude vinylene carbonate to obtain vinylene carbonate.

[0037] In another preferred embodiment, the temperature inside the condenser is 50-60°C.

[0038] In another preferred embodiment, the preparation method comprises the following steps:

[0039] S1. Forming a catalyst raw material, then calcining at 90-150 ° C for 12-48h, calcining at 450-550 ° C for 5-15h, and then cooling to obtain catalyst particles; wherein the particle size of the catalyst particles is 1mm-5mm;

[0040] S2. 250-350 mL of catalyst is filled into the reaction bed of the reactor;

[0041] S3. The carrier gas and ethylene carbonate preheated to 300 ℃ -450 ℃ are simultaneously introduced into a vaporizer preheated to 300 ℃ -450 ℃, so that the ethylene carbonate is vaporized and mixed with the carrier gas to form a material gas stream containing ethylene carbonate;

[0042] S4. The gas flow of the material containing ethylene chloride carbonate is introduced into the reaction bed containing the catalyst to contact the reaction to obtain a product gas stream; wherein the reaction temperature is 300-400 ℃;

[0043] S5. The product gas stream is introduced into a condenser for condensation to obtain a crude vinylene carbonate;

[0044] S6. distilling the crude vinylene carbonate to obtain vinylene carbonate.

[0045] In another preferred embodiment, the preparation method comprises the following steps:

[0046] S1. Forming a catalyst raw material, then calcining at 90-150 ° C for 12-48h, calcining at 450-550 ° C for 5-15h, and then cooling to obtain catalyst particles; wherein the particle size of the catalyst particles is 1mm-5mm;

[0047] S2. 250-350 mL of catalyst is filled into the reaction bed of the reactor;

[0048] S3. The ethylene chloride is introduced into a vaporizer having an internal pressure of 100Pa-10000Pa and preheated to 300 ℃ -450 ℃, so that the ethylene chloride is gasified to form a gas stream containing ethylene chloride;

[0049] S4. The gas flow of the material containing ethylene chloride carbonate is introduced into the reaction bed containing the catalyst to contact the reaction to obtain a product gas stream; wherein the reaction temperature is 300-400 ℃;

[0050] S5. The product gas stream is introduced into a condenser for condensation to obtain a crude vinylene carbonate;

[0051] S6. distilling the crude vinylene carbonate to obtain vinylene carbonate.

[0052] It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features described in detail below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be listed here one by one. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] FIG1 is a schematic structural diagram of the continuous flow reaction equipment used in Examples 1-2 of the present invention. DETAILED DESCRIPTION

[0054] After extensive and in-depth research, the applicant unexpectedly discovered that a catalyst for producing vinylene carbonate with long catalyst life and excellent mechanical strength can be prepared by forming and then calcining the catalyst. This catalyst can be used in fixed-bed or fluidized-bed processes to produce vinylene carbonate, requiring minimal equipment complexity and production costs, making it suitable for industrial production. Based on this discovery, the inventors completed the present invention.

[0055] the term

[0056] As used herein, the term "Group VIII elements" refers to Fe, Co, Ni, ruthenium (Ru), rhodium (Rh), palladium (Pb), osmium (Os), iridium (Ir), platinum (Pt).

[0057] As used herein, the term "Group IB elements" refers to Cu, Ag, Au.

[0058] As used herein, the term "Group IIB elements" refers to Zn, cadmium (Cd), and Hg.

[0059] As used herein, the term "Group IIIB elements" refers to scandium (Sc), yttrium (Y), lanthanides, and actinides, wherein lanthanides include lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

[0060] As used herein, the term "Group IVB elements" refers to titanium (Ti), zirconium (Zr), and hafnium (Hf).

[0061] As used herein, the term "VB group elements" refers to vanadium (V), niobium (Nb), and tantalum (Ta).

[0062] As used herein, the term "VIB Group elements" refers to chromium (Cr), molybdenum (Mo), and tungsten (W).

[0063] As used herein, the term "Group VIIB elements" refers to manganese (Mn), technetium (Tc), and rhenium (Re).

[0064] As used herein, the term "Group IA metal element" refers to lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).

[0065] As used herein, the term "Group IIA elements" refers to beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).

[0066] As used herein, the term "Group IIIA elements" refers to boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl).

[0067] As used herein, the term "Group IVA elements" refers to carbon (C), silicon (Si), germanium (Ge), tin (Sn), and lead (Pb).

[0068] In this article, when an element has multiple valence states, the corresponding cation can be of any valence state. For example, the salt formed by Cu can be a copper salt (Cu 2+ ) or cuprous salts (Cu + ).

[0069] As used herein, the terms "phosphate" and "phosphate compound" are used interchangeably to refer to a cation of the corresponding element and a phosphate radical (PO4 3- ) jointly formed salts.

[0070] As used herein, the terms "sulfate" or "sulfate compound" are used interchangeably to refer to the reaction between the cation of the corresponding element and the sulfate radical (SO4 2- ) jointly formed salts.

[0071] The terms "carbonate" and "carbonate compound" are used interchangeably to refer to the carbonate ion (CO3 2- ) jointly formed salts.

[0072] The term "oxide" refers to a complex of a corresponding element and oxygen, wherein when the element has multiple stable valence states, the element can be in any valence state.

[0073] The term "fluoride" refers to a complex of a corresponding element and fluorine, wherein when the element has multiple stable valence states, the element can be in any valence state.

[0074] The term "chloride" refers to a complex of the corresponding element and chlorine, wherein when the element has multiple stable valence states, the element can be in any valence state.

[0075] As used herein, the term "elemental carbon" includes any carbon element, such as activated carbon, or graphene.

[0076] Catalyst preparation suitable for fixed bed preparation process

[0077] In the present invention, a fixed bed process is used to prepare the vinylene carbonate. Since the catalyst traditionally used for this type of reaction is in powder form and cannot be produced when used in a fixed bed process, the inventors processed the catalyst in the reaction to form a shaped structure for use in a fixed bed process.

[0078] In the present invention, an exemplary catalyst preparation method is as follows: the catalyst raw material is formed, calcined, and then cooled to obtain catalyst particles. Preferably, the calcination comprises calcining at 90-130°C for 12-48 hours, followed by calcining at 450-550°C for 5-15 hours.

[0079] The catalyst of the present invention may be a single-component catalyst or a composite catalyst. In one preferred embodiment, the catalyst used in the present invention includes a catalyst selected from Group A (or consists of one or more catalysts selected from Group A); or the catalyst includes a catalyst selected from Group A and a catalyst selected from Group B (or consists of one or more catalysts selected from Group A and one or more catalysts selected from Group B);

[0080] Group A: Group IIA oxides, Group IIA metal sulfates, Group IB metals, Group IB metal chlorides, Group IB metal oxides, Group IIIA metal chlorides, Group IIIB metal oxides, Group IIIA metal oxides, Group VB metal oxides, VIB metal chlorides, Group VIIB metal oxides, Group VIII metals, Group VIII oxides, Group VIII metal chlorides, or combinations thereof;

[0081] Group B: oxides of Group IIIA elements, simple substances of Group IVA elements, oxides of Group IVA elements, Group IVB metal oxides, Group VIIB metal oxides, or combinations thereof.

[0082] In another preferred embodiment, the catalyst includes a catalyst selected from Group A; or the catalyst includes a catalyst selected from Group A and Group B;

[0083] Group A: ferroferric oxide, magnesium oxide, copper chloride, silver, gallium chloride, gallium oxide, manganese oxide, zinc oxide, indium oxide, cobalt oxide, ferrous oxide, ruthenium, cerium dioxide, chromium chloride, calcium sulfate, palladium oxide, palladium dichloride, nickel oxide, manganese dioxide, vanadium pentoxide, or a combination thereof;

[0084] Group B: titanium dioxide, manganese dioxide, aluminum oxide (preferably gamma-alumina), silicon dioxide, activated carbon, zirconium oxide, or a combination thereof.

[0085] In another preferred embodiment, the catalyst includes a catalyst selected from Group A; or the catalyst includes a catalyst selected from Group A and Group B;

[0086] Group A: ferroferric oxide, magnesium oxide, copper chloride, silver, gallium chloride, gallium oxide, manganese oxide, zinc oxide, indium oxide, cobalt oxide, ferrous oxide, ruthenium, cerium dioxide, or a combination thereof;

[0087] Group B: titanium dioxide, manganese dioxide, aluminum oxide (preferably gamma-alumina), silicon dioxide, activated carbon, zirconium oxide, or a combination thereof.

[0088] In a preferred embodiment of the present invention, the catalyst raw material includes a catalyst combination selected from the following group: silicon dioxide, ferric chloride, barium fluoride, titanium dioxide, nickel oxide, manganese dioxide, vanadium pentoxide, nickel oxide, zinc chloride, palladium dichloride / γ-alumina, palladium oxide / silicon dioxide, calcium sulfate, zinc chloride / silicon dioxide, chromium trichloride, ferrous oxide, γ-alumina / magnesium oxide, ferrous oxide / silicon dioxide, copper chloride / activated carbon, silver / silicon dioxide, magnesium oxide / titanium dioxide / silicon dioxide, gallium chloride / silicon dioxide, gallium oxide / magnesium oxide, manganous oxide / zirconium oxide, zinc oxide / silicon dioxide, indium oxide / γ-alumina, cobalt oxide, ferrous oxide / silicon dioxide, ferrous oxide / silicon dioxide, silver / silicon dioxide, ferrous oxide, magnesium oxide / titanium dioxide / silicon dioxide, ruthenium / activated carbon, manganese dioxide / γ-alumina / cerium dioxide, calcium phosphate, zirconium oxide, or a combination thereof.

[0089] In the present invention, a catalyst suitable for a fixed bed process is formed by shaping and calcining, thereby obtaining a method for efficiently producing vinylene carbonate. In a preferred embodiment, when the catalyst is a single-component catalyst, the method comprises the following steps:

[0090] The raw materials are shaped, calcined at 110°C for 24 hours, then heated to 500°C and calcined for 10 hours, and then cooled naturally to obtain the catalyst. The mechanical strength of the obtained catalyst is greater than 50N.

[0091] When the catalyst is a multi-component catalyst, the process comprises the following steps:

[0092] The raw materials of each component are mixed evenly, formed, calcined at 110°C for 24 hours, then heated to 500°C and calcined for 10 hours, and then cooled naturally to obtain the catalyst. The mechanical strength of the obtained catalyst is greater than 50N.

[0093] In another preferred embodiment, when the catalyst component contains raw materials with a melting point below 500° C. (such as ferric chloride, zinc chloride, etc.), the raw materials are not calcined after forming and are directly used to fill the fixed bed.

[0094] Reactor for preparing vinylene carbonate by continuous flow reaction

[0095] In the following examples, unless otherwise specified, the reaction equipment used is a continuous flow reaction device, the structural schematic diagram of which is shown in FIG1 , which specifically includes: a vaporization tank, a reactor, a condenser, and a receiving tank.

[0096] The vaporizer has at least one inlet and one outlet. The inlet is used to simultaneously introduce ethylene chlorocarbonate and a carrier gas. In some embodiments, ethylene chlorocarbonate is introduced directly without introducing a carrier gas. In this case, the inlet for introducing the carrier gas is sealed. The outlet of the vaporizer is connected to the reactor.

[0097] The reactor has at least one inlet and one outlet. The reactor inlet is connected to the vaporizer outlet, and the reactor outlet is connected to the condenser. The reactor also has at least one cavity for accommodating the catalyst. The cavity is cylindrical with an inner diameter of 26 mm and a height of 300 mm. Specifically, the reaction used in Examples 1-2 is a fixed bed reactor, but a fluidized bed reactor may also be used in other embodiments. Preferably, the reactor does not contain a stirring device.

[0098] In a preferred embodiment, the condenser has at least one inlet and one liquid phase outlet, the inlet of the condenser is connected to the outlet of the reactor, and the liquid phase outlet of the condensed gas is connected to the receiving tank.

[0099] In a preferred embodiment, the receiving tank has at least one inlet and one outlet, the inlet of the receiving tank is connected to the outlet of the condenser, and the outlet of the receiving tank is used to discharge the collected product.

[0100] In a preferred embodiment, the gasification tank and the reactor both have heating and temperature control functions.

[0101] In a preferred embodiment, the condenser further comprises a gas phase outlet for discharging uncondensed components (primarily HCl). In another preferred embodiment, the uncondensed components are discharged from the gas phase outlet and then introduced into water for further absorption.

[0102] Advantages of the present invention

[0103] (1) The method for preparing vinylene carbonate of the present invention adopts a fixed bed process, and no additional stirring of the catalyst is required during the reaction process, thereby greatly reducing the cost of the production equipment and simplifying the production process. Even if it is operated for a long time, the catalyst will not produce pulverization.

[0104] (2) The present invention provides a catalyst suitable for a fixed bed. During the preparation of the catalyst, the catalyst is first formed and then calcined. The obtained catalyst has high mechanical strength and will not pulverize during the reaction. The single life of the catalyst can reach more than 100 hours, and the cumulative life after activation can reach more than 1000 hours.

[0105] (3) The prior art suggests the use of a variety of different metal elements or complexes as catalysts. However, the inventors have found that when a fixed bed process is used and a shaped catalyst is used, the use of an oxide-containing catalyst can achieve a yield far superior to that of other catalyst types.

[0106] (4) A new composite catalyst was used to reduce the side reaction of deep cracking while maintaining a conversion rate of more than 98%, thereby increasing the product yield to a maximum of 84%, which is better than the existing technology.

[0107] In order to make the technical means, creative features, purpose and effect of the present invention easy to understand, the present invention is described in detail below in conjunction with Examples and accompanying drawings. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are usually carried out according to conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise stated, percentages and parts are weight percentages and parts by weight, and each raw material is a commercially available product.

[0108] General Methods: Catalyst Preparation

[0109] In various embodiments of the present invention, when the catalyst is a single-component catalyst, the catalyst is prepared by the following steps:

[0110] i. Molding the raw materials: Powder and mix the raw materials thoroughly, extrude with a single screw, and cut into spheres;

[0111] ii. Calcination: calcined at 110 ° C for 24 h, then heated to 500 ° C and continued calcined for 10 h;

[0112] iii. Let it cool down naturally.

[0113] When the catalyst is a multi-component catalyst, the catalyst is prepared by the following steps:

[0114] I. Mix all the raw materials evenly and shape them: grind the raw materials into powder and mix them thoroughly, extrude them into balls with a single screw, and cut them into spheres;

[0115] II. Calcination: Calcination at 110 ° C for 24 h, then heating to 500 ° C and continuing calcination for 10 h;

[0116] III. Let the temperature drop naturally.

[0117] Catalyst performance testing

[0118] The mechanical strength of the catalyst was tested according to GB 3635-1983. The test results showed that the mechanical strength of the obtained catalyst was greater than 50N.

[0119] In addition, the BET test method was used to test that the specific surface area of ​​each catalyst prepared by the present invention was greater than 200m 2 / g.

[0120] Example 1 Preparation of vinylene carbonate

[0121] This embodiment provides a method for preparing vinylene carbonate, and the reaction steps are as follows:

[0122] The pressure in the vaporizer is controlled between 800 Pa and 900 Pa, and the internal atmosphere is heated to 300°C. Ethylene chlorocarbonate is introduced into the vaporizer at a feed rate of 25 mL / min. The ethylene chlorocarbonate entering the vaporizer rapidly vaporizes, and the vaporized ethylene chlorocarbonate is then introduced into the reactor at a rate of 25 mL / min. The reactor is preheated to 360°C and filled with 300 mL of ferrosoferric oxide catalyst with an average particle size of 3 mm. Under the action of the catalyst, the ethylene chlorocarbonate undergoes a cracking reaction to produce vinylene carbonate, with an average residence time of 1 second in the reactor. The product gas stream exits the reactor and enters a condenser, where the product is condensed to 50°C and liquefied into a liquid. The liquefied product is then collected in a receiving tank to obtain a crude product.

[0123] When the reaction was carried out for 48 hours, a sample was taken from the condenser outlet and the sample was tested by GC. The GC spectrum is shown in the following table. When the reaction was carried out for 48 hours, the reaction conversion rate was still as high as 99.2%, and the content of the target product vinylene carbonate in the sample was 91.2%:

[0124] The crude product generated by the reaction within 48 hours was collected and purified by distillation, and vinylene carbonate with a purity of 99.5% was finally obtained with a yield of 76%.

[0125] Example 2 Preparation of vinylene carbonate

[0126] This embodiment provides a method for preparing vinylene carbonate, and the reaction steps are as follows:

[0127] Nitrogen, serving as a carrier gas, is heated to 300°C and introduced at a rate of 8 L / min into a preheated vaporizer at 300°C. Simultaneously, liquid ethylene chlorocarbonate is introduced into the vaporizer at a rate of 25 mL / min. The ethylene chlorocarbonate rapidly vaporizes and enters the reactor along with the carrier gas. The reactor, preheated to 360°C, is filled with 300 mL of ferrosoferric oxide (Fe3O4) with an average particle size of 3 mm. Under the action of the catalyst, the ethylene chlorocarbonate undergoes a cracking reaction to produce vinylene carbonate. The average residence time in the reactor is 1.5 seconds. The product gas stream exits the reactor and enters a condenser, where the product is condensed to 50°C and liquefied into a liquid. The liquefied product is then collected in a receiving tank to yield the crude product.

[0128] When the reaction was carried out for 48 hours, a sample was taken from the condenser outlet and the sample was subjected to GC detection. The GC detection results are shown in the following table. When the reaction was carried out for 48 hours, the reaction conversion rate was still as high as 99.2%, and the content of the target product vinylene carbonate in the sample was 85.1%:

[0129] The crude product generated by the reaction within 48 hours was collected and purified by distillation, and vinylene carbonate with a purity of 99.5% was finally obtained with a yield of 69%.

[0130] Example 3 Screening of catalysts

[0131] This example screened the catalyst based on Examples 1-2. The screening methods include the following two:

[0132] Method A:

[0133] The pressure in the vaporizer was controlled between 800 Pa and 900 Pa, and the internal atmosphere was heated to 300°C. Ethylene chlorocarbonate was introduced into the vaporizer at a feed rate of 25 mL / min. The ethylene chlorocarbonate rapidly vaporized within the vaporizer, and the vaporized ethylene chlorocarbonate was then introduced into the reactor at a rate of 25 mL / min. The reactor was preheated to 360°C and filled with 300 mL of a catalyst with an average particle size of 3 mm. Under the action of the catalyst, the ethylene chlorocarbonate underwent a cracking reaction to produce vinylene carbonate. The average residence time of the material in the reactor was 1.5 seconds. The product gas stream exited the reactor and entered a condenser, where the product was condensed to 50°C and liquefied into a liquid. Samples were taken from the condenser outlet every 30 minutes to measure the reaction conversion and vinylene carbonate content. The liquefied product was collected in a receiving tank to obtain a crude product. The crude product collected within 48 hours of reaction was collected and purified by distillation to obtain vinylene carbonate.

[0134] Method B:

[0135] Nitrogen, serving as a carrier gas, was heated to 300°C and introduced at a rate of 8 L / min into a preheated vaporizer at 300°C. Simultaneously, liquid ethylene chlorocarbonate was introduced into the vaporizer at a rate of 25 mL / min. The ethylene chlorocarbonate rapidly vaporized and entered the reactor along with the carrier gas. The reactor, preheated to 360°C, was filled with 300 mL of a catalyst with an average particle size of 3 mm. Under the action of the catalyst, the ethylene chlorocarbonate cracked to form vinylene carbonate, with an average residence time of 1.5 s in the reactor. The product stream exited the reactor and entered a condenser, where it was condensed to 50°C and liquefied into a liquid. Samples were taken from the condenser outlet every 30 minutes to measure the reaction conversion and vinylene carbonate content. The liquefied product was collected in a receiving tank to yield a crude product. The crude product collected within 48 hours of reaction was collected and purified by distillation to obtain vinylene carbonate.

[0136] The screening results are shown in Table 1.

[0137] Table 1 Catalyst screening a. In the multi-component catalyst, all percentages are weight percentages; b. Conversion = (1-chloroethylene carbonate content) × 100%, where chloroethylene carbonate content = chloroethylene carbonate content in a sample obtained from the condenser outlet at 48 hours of reaction, as determined by GC; c. VC content = vinylene carbonate content in a sample obtained from the condenser outlet at 48 hours of reaction, as determined by GC; d. VC yield = molar amount of vinylene carbonate obtained after distillation of the crude product collected from 0-48 hours of reaction / molar amount of chloroethylene carbonate consumed from 0-48 hours of reaction, where the purity of the vinylene carbonate obtained after distillation is ≥99.5%; e. Catalyst life = time from the start of the reaction to the first time the conversion falls below 50%; f. Reactor temperature, 300°C; g. Prepared with reference to Example 1 of CN200680016151.X; h. The preparation method is to mix the raw materials and then shape them. The shaping method is the same as other catalysts, but does not include the calcination step.

[0138] As can be seen from the above table, the catalyst effect provided by the present application is significantly better than some catalyst effects reported in existing literature. Since the catalyst provided by the present application has undergone steps such as molding and calcination, the overall mechanical strength is much greater than that of traditional catalysts using carriers, so pulverization does not occur during the reaction, and the catalyst life can reach more than 100 hours. As can be seen from entries 25 and 36 in Table 1, when other conditions are the same and only the catalyst is calcined, the catalyst life and product conversion rate are significantly improved. This result shows that calcining the catalyst can effectively improve the catalyst life, product conversion rate and VC content in the product in the process of the present invention.

[0139] In terms of catalyst selection, the applicant found that chlorides generally have a poor performance. This is because transition metal chloride catalysts, such as zinc chloride, can lead to increased deep cracking side reactions and severe carbon deposition on the catalyst, which can hinder the catalytic reaction. However, using oxides as catalysts can achieve yields far superior to those achieved with other catalysts.

[0140] The above embodiments are preferred examples of the present invention and are not intended to limit the scope of protection of the present invention.

[0141] All documents mentioned in this application are incorporated herein by reference, just as if each document were incorporated herein by reference individually. It should also be understood that after reading the above teachings of the present invention, those skilled in the art may make various changes or modifications to the present invention, and that such equivalents also fall within the scope of the claims appended hereto.

Claims

1. A method for preparing vinylene carbonate, characterized in that, It includes the following steps: feeding a material containing vinyl chloroformate into a reaction bed layer containing a catalyst to make them contact and react, thereby obtaining vinylene carbonate; Among them, the catalyst is prepared by the following method: shaping the catalyst raw materials, then optionally calcining, and then cooling to obtain catalyst particles; preferably, the reaction temperature is 100-400 °C.

2. The preparation method according to claim 1, characterized in that, The contact time is 0.5-120 s.

3. The preparation method according to claim 1, characterized in that, The calcination includes: calcining at 90-150 °C for 12-48 h, and then calcining at 450-550 °C for 5-15 h.

4. The preparation method according to claim 1, characterized in that, The reaction is carried out in a reactor filled with a catalyst particle bed.

5. The preparation method according to claim 1, characterized in that, The particle size of the catalyst is 1 mm-5 mm, preferably 2 mm-4 mm.

6. The preparation method according to claim 4, characterized in that, The inner diameter of the cavity for filling the catalyst particle bed in the reactor is 20 mm-30 mm, and the filling amount of the catalyst is 250-350 mL.

7. The preparation method according to claim 1, wherein, The catalyst is prepared by the following method: shaping the catalyst raw materials, then calcining at 100-150 °C for 20-36 h, calcining at 450-550 °C for 8-12 h, and then cooling to obtain catalyst particles.

8. The preparation method according to claim 1, wherein The catalyst raw materials include a catalyst selected from Group A; or the catalyst raw materials include a catalyst selected from Group A and a catalyst selected from Group B; Group A: oxides of Group IIA, sulfates of Group IIA metals, elemental metals of Group IB, chlorides of Group IB metals, oxides of Group IIB metals, chlorides of Group IIIA metals, oxides of Group IIIB metals, oxides of Group IIIA metals, oxides of Group VB metals, chlorides of VIB metals, oxides of Group VIIB metals, elemental metals of Group VIII, oxides of Group VIII, chlorides of Group VIII metals, or combinations thereof; Group B: oxides of Group IIIA elements, elemental metals of Group IVA, oxides of Group IVA elements, oxides of Group IVB metals, oxides of Group VIIB metals, or combinations thereof.

9. The preparation method according to claim 8, characterized in that, The catalyst raw materials include a catalyst selected from Group A; or the catalyst raw materials include a catalyst selected from Group A and a catalyst selected from Group B; Group A: iron tetroxide, magnesium oxide, copper chloride, silver, gallium chloride, gallium oxide, manganese oxide, zinc oxide, indium oxide, cobalt oxide, iron(III) oxide, ruthenium, cerium dioxide, chromium(III) chloride, calcium sulfate, palladium oxide, palladium dichloride, nickel oxide, manganese dioxide, vanadium pentoxide, or combinations thereof; Group B: titanium dioxide, manganese dioxide, alumina (preferably γ-alumina), silicon dioxide, activated carbon, zirconium oxide, or combinations thereof.

10. The preparation method according to claim 8, characterized in that The catalyst raw materials include a catalyst selected from Group A; or the catalyst raw materials include a catalyst selected from Group A and a catalyst selected from Group B; Group A: iron tetroxide, magnesium oxide, copper chloride, silver, gallium chloride, gallium oxide, manganese oxide, zinc oxide, indium oxide, cobalt oxide, iron(III) oxide, ruthenium, cerium dioxide, or combinations thereof; Group B: titanium dioxide, manganese dioxide, alumina (preferably γ-alumina), silicon dioxide, activated carbon, zirconium oxide, or combinations thereof.

11. The preparation method according to claim 1, characterized in that, During the contact of gaseous or liquid vinyl chloroformate with the catalyst, stirring is not carried out.

12. The preparation method according to claim 1, wherein, The material containing vinyl chloroformate is formed by the following method: introducing a carrier gas preheated to 300°C - 450°C and vinyl chloroformate into a vaporization tank preheated to 300°C - 450°C, vaporizing the vinyl chloroformate and mixing it with the carrier gas, thereby forming the material containing vinyl chloroformate.

13. The preparation method according to claim 12, characterized in that, The carrier gas is selected from the following group: argon, helium, neon, nitrogen, carbon monoxide, carbon dioxide, hydrogen chloride gas, water vapor, or a combination thereof.

14. The preparation method according to claim 1, wherein The material containing vinyl chloroformate is formed by the following method: introducing vinyl chloroformate into a vaporization tank with an internal pressure of 100 Pa - 10,000 Pa and preheated to 300°C - 450°C, vaporizing the vinyl chloroformate, thereby forming the material containing vinyl chloroformate.

15. The preparation method according to claim 1, characterized in that, The method further includes the following steps: passing the product gas stream into a condenser for condensation to obtain crude vinylene carbonate; preferably, the method further includes the following steps: rectifying the crude vinylene carbonate to obtain vinylene carbonate.

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