A reactor, reaction system, and method for synthesizing carbonates, and the resulting carbonates.

Abstract

This invention discloses a reactor, reaction system, and method for synthesizing carbonates, as well as the resulting carbonates. A catalyst bed is disposed in the middle of the reactor, and an intercepting filter and a liquid phase collection component are disposed above the catalyst bed. The liquid phase collection component is a hollow annular structure. A liquid phase outlet pipe is disposed between the liquid phase collection component and the liquid phase reaction product outlet for discharging the liquid phase reaction product collected by the liquid phase collection component. The reaction system includes a mixer, a dissolver, the reactor, a buffer tank, and a circulating pump connected in sequence. This invention solves problems such as catalyst loss, upper screen clogging, insufficient liquid flux in the catalyst bed, large amounts of gas entrainment in the circulating liquid, and gas trapping in the circulating pump in existing carbonate production equipment, and can be applied to the industrial production of carbonates.

Description

Technical Field

[0001] This invention belongs to the field of carbonate synthesis, and particularly relates to a reactor, reaction system and method for synthesizing carbonates and the carbonates obtained therefrom. Background Technology

[0002] Realizing the recovery and utilization of CO2 can effectively reduce CO2 emissions and contribute to ecological balance. From a resource perspective, CO2 resources are abundant and inexpensive. Therefore, promoting the rational utilization of CO2 is of great significance for developing advanced fine chemicals and increasing the added value of products.

[0003] There are three main methods for synthesizing carbonates: phosgene method, transesterification method, and addition method of epoxides with carbon dioxide.

[0004] The phosgene process was a commonly used method for synthesizing carbonates in the past, but phosgene is highly toxic and causes serious environmental pollution, so this method has been gradually replaced.

[0005] The transesterification method involves reacting carbonates with alcohols. However, this method uses relatively expensive raw materials and has low catalyst efficiency. If these two problems can be overcome, this synthetic method will have better development prospects.

[0006] The addition reaction of epoxides with CO2 to produce carbonates is a relatively mature process, divided into homogeneous and heterogeneous methods, each employing different catalyst systems. The homogeneous method suffers from difficulties in separating the catalyst from the product, while the heterogeneous method reduces the investment costs associated with catalyst-product separation, and the catalyst can be reused, resulting in high catalyst efficiency. This addition reaction process effectively utilizes CO2 as a raw material to produce high-value-added carbonate products, possessing significant practical value and providing valuable guidance for sustainable development.

[0007] CN108484565A discloses a system for producing carbonates and a method for producing carbonates using this system. The reaction system includes a first bubble column, a second bubble column, and a heat exchanger. The top of the first bubble column is connected to the outlet of the heat exchanger, and the bottom is connected to the circulation outlet of the second bubble column. The bottom of the second bubble column is connected to the bottom of the first bubble column, and a gas inlet is provided at the bottom, while an overflow outlet is provided at the top. According to the patent description, this process can effectively shorten the residence time and reduce the reaction temperature and pressure; however, the use of a homogeneous catalyst in this reaction process will inevitably cause difficulties in the subsequent separation process and increase the investment in the process.

[0008] CN206404755U discloses a reactor for producing ethylene carbonate. The process includes a primary reactor and a secondary reactor, both of which are tubular reactors, which can be coiled or vertical. The primary reactor receives the raw material, and the secondary reactor is connected to the primary reactor. This two-stage tubular reactor can perform multiple reaction processes, which can improve the material conversion rate. However, because the tubular reactors are connected in series, the reaction mainly concentrates in the first reactor, which is not conducive to timely heat removal and may lead to temperature runaway.

[0009] CN206309596U discloses a vacuum system for producing ethylene carbonate. The system is a Roots pump set, which includes three Roots pumps. The pumping end of the Roots pump is connected to the vacuum system to be evacuated, and the output end is connected to a water ring vacuum pump. The three Roots pumps and the matching water ring pump are arranged vertically in sequence, which can greatly improve the service life of the device. However, the industrial applicability of this process is currently unknown.

[0010] CN1371900A discloses a method and reactor for preparing propylene carbonate or ethylene carbonate. The reaction involves placing the catalyst in a reactor with heat removal measures, divided into a reaction zone and a product zone. Simultaneous heat removal during the reaction avoids high-temperature deactivation of the catalyst and enables continuous product extraction. However, this reactor is difficult to manufacture, and the material is prone to uneven distribution, making practical application challenging. Summary of the Invention

[0011] The heterogeneous method for synthesizing carbonates eliminates the need for subsequent product-catalyst separation compared to the homogeneous method, reducing equipment investment. However, this process presents several other challenges. To overcome these issues, this invention provides a reactor, reaction system, and method for synthesizing carbonates, along with the resulting carbonates. The primary objective of this invention is to address problems in existing carbonate production equipment, such as catalyst loss, wire mesh blockage, gas trapping in the circulating pump, difficulty in increasing circulation volume, and uneven gas or liquid distribution within the reactor. Furthermore, the invention incorporates control measures to simplify the carbonate production process, demonstrating its practicality.

[0012] One of the objectives of this invention is to provide a reactor for synthesizing carbonates, wherein a catalyst bed is provided in the middle of the reactor, and an intercepting filter and a liquid phase extraction component are provided above the catalyst bed.

[0013] In a preferred embodiment, a liquid-phase feed inlet is provided below the catalyst bed, and a liquid-phase reaction product outlet is provided above the reactor.

[0014] In a further preferred embodiment, the liquid phase feed inlet is located at the bottom of the reactor, and the liquid phase reaction product outlet is located on one side of the liquid phase extraction component and is in communication with the liquid phase extraction component.

[0015] In a preferred embodiment, a gas inlet II is provided below the catalyst bed, and a gas outlet is provided above the liquid phase extraction component.

[0016] In a further preferred embodiment, the gas outlet is located at the top of the reactor.

[0017] In a further preferred embodiment, a pressure regulating valve is provided on the pipe connected to the gas outlet.

[0018] The pressure of the reaction system is controlled by a pressure regulating valve at the top of the reactor.

[0019] In a preferred embodiment, the catalyst bed is disposed on a catalyst support plate.

[0020] In a further preferred embodiment, a wire mesh is also provided between the catalyst bed and the catalyst support plate.

[0021] In a further preferred embodiment, the wire mesh is a planar mesh structure, preferably a woven wire mesh, and the wire mesh diameter is smaller than the particle size of the catalyst.

[0022] In a preferred embodiment, a gas distributor is provided below the catalyst bed and is connected to the gas inlet II.

[0023] In a further preferred embodiment, the gas distributor is an annular tubular structure with multiple upward-facing gas outlet pipes provided on the annulus.

[0024] The reason for designing it as a ring structure is to facilitate the upward feeding of liquid raw materials into the catalyst bed through the hollow part of the ring.

[0025] In a further preferred embodiment, the air outlet pipe is in the form of a straight pipe or a branch pipe (the branch pipe can be V-shaped or Y-shaped).

[0026] The gas distributor is not limited to the structure described above; any gas distributor disclosed in the prior art can be used, as long as it can achieve the purpose of gas distribution.

[0027] In a preferred embodiment, the distance between the gas distributor and the catalyst support plate is 100-800 mm, preferably 200-500 mm.

[0028] In a further preferred embodiment, the distance between the gas distributor and the catalyst support plate is 250-400 mm.

[0029] The gas distributor is located below the catalyst support plate with its opening facing upwards. A certain distance needs to be set between the gas distributor and the catalyst support plate to prevent uneven gas distribution if the distance is too short and excessive resistance drop when the gas passes through the catalyst bed if the distance is too large. Preferably, the distance between the gas distributor and the catalyst support plate is 100-800mm, more preferably 200-500mm, and most preferably 250-400mm.

[0030] In a preferred embodiment, the liquid phase extraction component is a hollow annular structure, preferably a circular or square annular structure.

[0031] In a further preferred embodiment, a plurality of interconnected liquid flow channels are provided on the liquid phase extraction component. Preferably, a plurality of interconnected liquid flow channels are provided on at least one side and inside the upper, lower, left and right sides of the liquid phase extraction component.

[0032] In a further preferred embodiment, a plurality of liquid flow channels are provided on at least one side and inside the liquid phase extraction component, which is located on the lower side, left side and right side, and an air hole is provided on the upper side.

[0033] In this invention, the liquid phase extraction component is used to uniformly collect and extract the liquid-phase reaction products flowing from bottom to top, ensuring a uniform liquid phase distribution within the reactor. Without this liquid phase extraction component, only the liquid-phase reaction products near the outlet would be more easily extracted. Therefore, in this invention, the liquid flows out of the reactor through liquid flow channels. This measure prevents liquid from concentrating and short-circuiting, resulting in a more uniform reaction within the reactor.

[0034] In a preferred embodiment, a liquid phase outlet pipe is provided between the liquid phase extraction component and the liquid phase reaction product outlet for outputting the liquid phase reaction products collected by the liquid phase extraction component.

[0035] In a further preferred embodiment, the liquid phase outlet pipe is connected to at least one of the plurality of interconnected liquid flow channels.

[0036] In a further preferred embodiment, the orifice diameter of the liquid flow channel and the pipe diameter of the liquid phase outlet pipe satisfy the condition shown in equation (I):

[0037] N*D1 2 ≥D2 2 Formula (I);

[0038] In equation (I), N represents the number of liquid flow channels, D1 represents the diameter of the liquid flow channels, and D2 represents the diameter of the liquid phase outlet pipe.

[0039] In this invention, the total opening area is the product of the number of liquid flow channels and the area of ​​each liquid flow channel. This area should be greater than the area of ​​the liquid phase outlet pipe; otherwise, the throughput will be limited by the opening area. When the condition shown in equation (I) is met, it can be ensured that the liquid phase collected by the liquid phase extraction component spontaneously flows through the liquid phase outlet pipe to the liquid phase reaction product outlet.

[0040] In a preferred embodiment, with the reactor inner diameter being 100%, the distance between the edge of the liquid phase extraction component and the reactor sidewall is not less than 10%, preferably not less than 20%.

[0041] In a further preferred embodiment, the liquid phase extraction component is symmetrically arranged along the central axis of the reactor.

[0042] In a preferred embodiment, the intercepting filter is a non-planar mesh structure, preferably a woven wire mesh.

[0043] In a further preferred embodiment, the intercepting filter is an arc-shaped, conical, square, or trapezoidal filter, preferably an arc-shaped or conical filter.

[0044] In a further preferred embodiment, the wire mesh diameter is smaller than the particle size of the catalyst.

[0045] In a preferred embodiment, the lowest point of the intercepting filter is located above the catalyst bed and below the liquid phase extraction component, and the highest point of the intercepting filter is located above the liquid level in the reactor.

[0046] In a further preferred embodiment, the area of ​​the intercepting filter is larger than the radial cross-sectional area of ​​the reactor.

[0047] In a further preferred embodiment, the highest point of the intercepting filter is higher than the liquid phase extraction component, and the higher portion passes through the hollow portion of the liquid phase extraction component.

[0048] In this way, the liquid phase extraction component is located between the highest and lowest points of the interception component, and the annular structure of the liquid phase extraction component is located outside the interception filter, which can intercept the catalyst from entering the interior of the liquid phase extraction component.

[0049] In this invention, the intercepting filter is positioned above the liquid phase of the reactor, which effectively intercepts the catalyst carried away by the reactants as they flow out, reducing catalyst loss and pipe blockage.

[0050] In a preferred embodiment, the reactor is a gas-solid-liquid three-phase reactor, and the ratio of the density of the catalyst particles packed on the catalyst bed to the density of the liquid-phase reaction products is 0.5 to 3, preferably 0.5 to 1.5.

[0051] In this way, controlling the density of catalyst particles to be similar to the density of liquid-phase reaction products is to enable them to be better suspended in the reaction space with the liquid or gas, rather than being fixedly piled up in the reactor.

[0052] In the prior art, CN106475017A discloses a multiphase reactor for carbonate synthesis. This multiphase reactor, from bottom to top, includes a liquid outlet, a liquid baffle, a gas inlet, a gas inlet distributor, a lower catalyst support sieve plate, a lower ceramic ball layer, a catalyst layer, an upper ceramic ball layer, an upper catalyst support sieve plate, a liquid inlet, a liquid feed distributor, and a gas outlet. In this reactor, the catalyst is fixed between the upper and lower ceramic balls and the support plate, resulting in disadvantages such as complex manufacturing, large pressure drop, easy catalyst blockage, and poor gas-liquid contact within the catalyst bed.

[0053] A second objective of this invention is to provide a reaction system for synthesizing carbonates, which includes the reactor described in one objective of this invention.

[0054] In a preferred embodiment, the reaction system includes the reactor and a buffer tank.

[0055] In a further preferred embodiment, a buffer material inlet is provided at the upper part of the buffer tank, and the buffer material inlet is connected to the liquid phase reaction product outlet of the reactor.

[0056] In a further preferred embodiment, a buffer material outlet is provided at the bottom of the buffer tank.

[0057] In a preferred embodiment, a gas balance pipe is provided between the buffer tank and the reactor.

[0058] In a further preferred embodiment, the gas balance pipe is provided between the top of the buffer tank and the top of the reactor.

[0059] In a preferred embodiment, the buffer tank includes a container and a heat exchanger located in the lower part of the container, preferably an integrated container and heat exchanger.

[0060] In a further preferred embodiment, the liquid level in the buffer tank is controlled to be above the heat exchanger and below the buffer material inlet.

[0061] That is, the liquid level in the buffer tank must satisfy the condition of equation (II):

[0062] Equation (II) is given by H1≤L≤H2.

[0063] In Equation (II), L represents the position from the liquid level in the buffer tank to the tangent position at the bottom of the reactor, H1 represents the position from the tube sheet opening of the heat exchanger to the tangent position at the bottom of the reactor, and H2 represents the position from the feed inlet of the buffer tank to the tangent position at the bottom of the reactor.

[0064] In a further preferred embodiment, circulating water is used as the refrigerant for the heat exchanger, preferably circulating water with a temperature of ≥45°C, and more preferably circulating water with a temperature of 50–80°C.

[0065] The heat exchanger is equipped with a temperature control valve to control the temperature of the circulating material based on the flow rate of the circulating water. Preferably, the heat exchanger has a buffer material running through the tubes and a refrigerant running through the shell. When the buffer material contains catalyst powder, the tube side is easier to clean.

[0066] In this invention, the system is equipped with heat removal measures, preferably using an external circulation heat removal method, and more preferably using a shell-and-tube heat exchanger installed inside a buffer tank, which can both stabilize the material flow and remove heat in a timely manner.

[0067] In a preferred embodiment, along the material flow direction, the reaction system includes a mixer, a dissolver, the reactor, the buffer tank, and a circulating pump connected in sequence.

[0068] In a preferred embodiment, the mixer is provided with an alkylene oxide inlet.

[0069] In a preferred embodiment, a gas inlet I is provided on the dissolver, and / or the dissolver is connected to the liquid phase feed inlet of the reactor.

[0070] In a preferred embodiment, one end of the circulating pump is connected to the buffer material outlet of the buffer tank, and the other end is connected to the mixer.

[0071] In a further preferred embodiment, a carbonate product outlet is provided between the circulating pump and the mixer.

[0072] In this invention, the pressure of the reaction system is controlled by a pressure regulating valve at the top of the reactor; the temperature of the reaction system is controlled by the flow rate and / or temperature of the refrigerant in the heat exchanger on the buffer tank, ensuring that the adiabatic temperature rise of the reactor is ≤50°C. The reactor does not require level control; the level of the buffer tank is controlled by the flow rate of the extracted carbonate product, ensuring that the level of the buffer tank meets the condition shown in equation (II).

[0073] The third objective of this invention is to provide a method for synthesizing carbonates, comprising: using epoxides and carbon dioxide as raw materials, introducing the raw materials into the reaction system described in the second objective of this invention to react and obtain carbonate products.

[0074] In a preferred embodiment, the method includes the following steps:

[0075] (1) The epoxy alkane raw material is introduced into the mixer and the dissolver in sequence, and at the same time, the first stream of carbon dioxide is introduced at the gas inlet I of the dissolver. The first stream of carbon dioxide and the epoxy alkane raw material form a liquid phase mixed raw material in the dissolver.

[0076] (2) The liquid-phase mixed raw material is introduced into the reactor through the liquid-phase raw material inlet of the reactor for reaction, and at the same time, a second stream of carbon dioxide is introduced into the reactor through the gas inlet II;

[0077] (3) In the reactor, the catalyst particles are intercepted by the interception filter and the liquid phase reaction products are collected by the liquid phase extraction component.

[0078] (4) The collected liquid reaction products enter the buffer tank from the buffer material inlet of the buffer tank and are cooled (by the heat exchanger in the buffer tank).

[0079] (5) The liquid-phase reaction product after cooling treatment enters the circulating pump from the buffer material outlet of the buffer tank. Part of the material is circulated by the circulating pump to form circulating material, which enters the mixer and is mixed with the epoxy alkane raw material. Part of the material is collected from the carbonate product outlet to obtain the carbonate product.

[0080] In a preferred embodiment, in step (1), the epoxide alkane feedstock is mixed with the recycled material from step (5) in the mixer, and then flows into the solvent in parallel with the first stream of carbon dioxide.

[0081] In this process, mixing a portion of the carbon dioxide with the reactants beforehand can effectively promote the conversion of epoxides.

[0082] In a preferred embodiment, in step (2), the second stream of carbon dioxide first enters the gas distributor through the gas inlet II, and after being evenly distributed by the gas distributor, it flows in parallel with the liquid-phase mixed raw material into the catalyst bed.

[0083] In this process, the second stream of carbon dioxide mixes and reacts with the upward-flowing liquid stream to produce a carbonate-containing liquid stream.

[0084] In a preferred embodiment, the mass ratio of the first stream of carbon dioxide to the second stream of carbon dioxide is (0-100):(0-100), preferably not both of them being 0.

[0085] In a further preferred embodiment, the mass ratio of the first stream of carbon dioxide to the second stream of carbon dioxide is (0-90):(10-100), preferably (10-50):(50-90).

[0086] In a preferred embodiment, the reaction pressure is controlled by a pressure regulating valve at the top of the reactor.

[0087] In a further preferred embodiment, the reaction pressure is discharged intermittently or continuously at low flow rates to effectively ensure the pressure stability of the operating system.

[0088] In a further preferred embodiment, the reaction pressure is controlled to be 1 to 6 MPaG, preferably 2 to 4 MPaG, for example 1 MPaG, 2 MPaG, 3 MPaG, 4 MPaG, 5 MPaG or 6 MPaG.

[0089] In a preferred embodiment, circulating water is used as the refrigerant for the heat exchanger, preferably circulating water with a temperature of ≥45°C, and more preferably circulating water with a temperature of 50–80°C.

[0090] In a preferred embodiment, in step (5), the recycling ratio is controlled to be 5 to 20, preferably 8 to 16, for example, the recycling ratio is 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20, wherein the recycling ratio is the weight ratio of the recycled material to the extracted carbonate product.

[0091] The temperature of the liquid reaction products (part of which is circulating material) entering the buffer tank is controlled by the flow rate and / or temperature of the refrigerant in the heat exchanger on the buffer tank. The circulating material is used to control the temperature of the reactor. Specifically, the low temperature of the circulating material is used to control the adiabatic temperature rise of the reactor. Generally, a higher circulation ratio results in a lower adiabatic temperature rise, and a lower circulation ratio results in a higher adiabatic temperature rise.

[0092] In a preferred embodiment, the adiabatic temperature rise of the reactor is controlled to be ≤50°C, which can prevent problems such as catalyst deactivation caused by excessively high temperatures.

[0093] For example, the adiabatic temperature rise of the reactor can be controlled at 50°C, 40°C, 30°C, 20°C, 10°C, or 5°C.

[0094] In a preferred embodiment, the reactor does not require level control and enters the buffer tank via overflow (using the liquid phase extraction component).

[0095] In a preferred embodiment, the liquid level in the buffer tank is controlled by the flow rate of the extracted carbonate product, so that the liquid level in the buffer tank satisfies the condition shown in equation (II).

[0096] In a preferred embodiment, the conversion rate of the carbonate product obtained by the method of the present invention is not less than 80%, and more preferably not less than 90%.

[0097] In this invention, the alkyl oxide is selected from ethylene oxide and / or propylene oxide.

[0098] The method of this invention effectively solves problems such as catalyst loss, wire mesh blockage, gas trapping in the circulating pump, difficulty in increasing the circulation volume, and uneven distribution of gas or liquid in the reactor in carbonate production equipment. It simplifies the process operation of carbonate production and can be applied to related industrial production.

[0099] The fourth objective of this invention is to provide a carbonate obtained by the method described in the third objective of this invention.

[0100] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In the following, various technical solutions can, in principle, be combined with each other to obtain new technical solutions, which should also be considered as specifically disclosed herein.

[0101] Compared with the prior art, the present invention has the following beneficial effects: The present invention solves the problems of catalyst loss, wire mesh blockage, insufficient liquid flux in catalyst bed, large amount of gas entrained in circulating liquid, and gas trapping in circulating pump in existing carbonate production equipment, and can be applied to the industrial production of carbonates. Attached Figure Description

[0102] Figure 1 A schematic diagram of the reaction system described in this invention is shown.

[0103] 1-Reactor; 11-Catalyst bed; 12-Interception filter; 13-Liquid phase extraction component; 131-Liquid flow channel; 132-Vacuum pore; 14-Catalyst support plate; 15-Gas distributor; 16-Liquid phase outlet pipe; 2-Buffer tank; 21-Buffer material inlet; 22-Liquid phase reaction product outlet; 23-Gas balance pipe; 24-Heat exchanger; 3-Circulation pump; 4-Mixer; 5-Dissolver; 6-Sycete carbonate product outlet.

[0104] a- Epoxyalkane feedstock; b- First stream of carbon dioxide; c- Second stream of carbon dioxide; d- Liquid-phase mixed feedstock; e- Exhausted gas (e.g., carbon dioxide); f- Mixed gas of carbon dioxide and epoxyalkane; g- Liquid-phase reaction products collected by the liquid-phase extraction component; h- Cooling medium (e.g., circulating water); i- Liquid-phase reaction products after cooling treatment; j- Circulating material; k- Carbonate product.

[0105] Figure 2 A front view schematic diagram of the liquid phase extraction component is shown.

[0106] Figure 3 The diagram shows a bottom view of the liquid phase extraction component.

[0107] The method includes the following steps:

[0108] (1) The epoxy alkane raw material a is introduced into the mixer 4 and the dissolver 5 in sequence, and the first carbon dioxide b is introduced into the gas inlet I of the dissolver 5. The first carbon dioxide b and the epoxy alkane raw material a form a liquid mixed raw material d in the dissolver.

[0109] (2) The liquid-phase mixed raw material d is introduced into the reactor 1 through the liquid-phase raw material inlet of the reactor 1 for reaction, and at the same time, a second stream of carbon dioxide c is introduced into the reactor through the gas inlet II;

[0110] The second stream of carbon dioxide c first enters the gas distributor 15 through the gas inlet II, and after being evenly distributed by the gas distributor 15, it flows in parallel with the liquid-phase mixed raw material d into the catalyst bed 11;

[0111] (3) In the reactor 1, the catalyst particles are intercepted by the interception filter 12 and the liquid phase reaction product g after the reaction is collected by the liquid phase extraction component 13.

[0112] (4) The collected liquid reaction product g enters the buffer tank 2 through the buffer material inlet 21 of the buffer tank 2 by overflow, and is cooled by the heat exchanger in the buffer tank.

[0113] (5) The liquid-phase reaction product i after cooling treatment enters the circulating pump 3 from the buffer material outlet 22 of the buffer tank 2. A portion of the material is circulated by the circulating pump 3 to form circulating material j, which enters the mixer 4 and is mixed with the epoxy alkane raw material a. A portion of the material is collected from the carbonate product outlet 6 to obtain carbonate product k. Detailed Implementation

[0114] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0115] It should also be noted that the various specific technical features described in the following embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the various possible combinations will not be described separately in this invention.

[0116] Furthermore, various embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention. The resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0117] The catalysts used in the examples and comparative examples were supported quaternary phosphate resin catalysts.

[0118] The catalyst has a particle size of 0.5 mm, and the filter screen used in the example has a diameter of 0.4 mm.

[0119] The structures of the liquid phase extraction components used in the embodiments and comparative examples are as follows: Figure 2 and Figure 3 As shown, four air holes with a diameter of 6 mm are uniformly arranged above the ring, and 16 liquid flow channels with a diameter of 20 mm are uniformly arranged below the ring.

[0120]

Example 1

[0121] Using carbon dioxide and ethylene oxide as raw materials, utilizing Figure 1 The system shown is used for the synthesis of carbonates:

[0122] (1) After the 100 kmol / h ethylene oxide raw material a is metered, it is mixed with the circulating material j in the mixer 4 and then enters the dissolver 5. At the same time, the first carbon dioxide b with a flow rate of 12 kmol / h is introduced into the dissolver 5. The first carbon dioxide b and the ethylene oxide raw material a form a liquid phase mixed raw material d in the dissolver.

[0123] (2) The liquid-phase mixed raw material d is introduced into the reactor 1 through the liquid-phase raw material inlet of the reactor 1 for reaction, and at the same time, a second stream of carbon dioxide c with a flow rate of 108 kmol / h is introduced into the reactor through the gas inlet II;

[0124] The second stream of carbon dioxide c first enters the gas distributor 15 through the gas inlet II. After being evenly distributed by the gas distributor 15, it flows upward together with the liquid mixed raw material d and enters the catalyst bed 11. The reaction pressure of the reactor is controlled at 2.4 MPaG.

[0125] (3) In the reactor 1, the catalyst particles are intercepted by the interception filter 12 and the liquid phase reaction product g after the reaction is collected by the liquid phase extraction component 13.

[0126] (4) The collected liquid reaction product g enters the buffer tank 2 through the buffer material inlet 21 of the buffer tank 2 by overflow, and the liquid reaction product is cooled to 90°C by cooling treatment.

[0127] (5) After cooling, the liquid phase reaction product i enters the circulating pump 3 from the buffer material outlet 22 of the buffer tank 2. A portion of the material is circulated by the circulating pump 3 to form circulating material j, which enters the mixer 4 and is mixed with the epoxy alkane raw material a. A portion of the material is collected from the carbonate product outlet 6 to obtain carbonate product k. The circulation ratio (mass ratio of reaction circulating material to reaction product collected material) is 14.

[0128] Using this method, the adiabatic temperature rise of the reactor is controlled at 15℃, the conversion rate of ethylene oxide is ≥85%, and the operation is stable.

[0129]

Example 2

[0130] The process of Example 1 is repeated, except that the flow rate of the first carbon dioxide stream b is 12 kmol / h and the flow rate of the second carbon dioxide stream c is 118 kmol / h.

[0131] Using this method, the conversion rate of ethylene oxide is ≥87%, and the operation is stable.

[0132]

Example 3

[0133] The process of Example 1 is repeated, except that the flow rate of the first carbon dioxide stream b is 20 kmol / h and the flow rate of the second carbon dioxide stream c is 115 kmol / h.

[0134] Using this method, the conversion rate of ethylene oxide is ≥87%, and the operation is stable.

[0135]

Example 4

[0136] The process of Example 1 was repeated, except that the reaction pressure in the reactor was controlled at 2.8 MPaG.

[0137] Using this method, the conversion rate of ethylene oxide is ≥95%, and the operation is stable.

[0138]

Example 5

[0139] The process of Example 1 was repeated, except that the reaction products were cooled, the recycle ratio was 12, and the adiabatic temperature rise of the reactor was 30°C.

[0140] Using this method, the conversion rate of ethylene oxide is ≥90%, and the operation is stable.

[0141]

Example 6

[0142] The process of Example 1 was repeated, except that the reaction products were cooled, the recycle ratio was 10, and the adiabatic temperature rise of the reactor was 45°C.

[0143] Using this method, the conversion rate of ethylene oxide is ≥83%, and the operation is stable.

[0144] Comparative Example 1

[0145] The process of Example 1 is repeated, except that the intercepting filter used in this example is entirely below the liquid level in the reactor. The catalyst clogs the filter, hindering liquid flow and affecting the stable operation of the device.

[0146] Comparative Example 2

[0147] The process of Example 1 is repeated, except that the liquid phase extraction component is not used.

[0148] Using this method, the conversion rate of ethylene oxide decreased by 2%.

[0149] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A reactor for synthesizing carbonates, comprising a catalyst bed in the middle of the reactor, an intercepting filter and a liquid phase extraction component above the catalyst bed; the liquid phase extraction component is a hollow annular structure, with multiple liquid flow channels provided on at least one of its lower, left, and right sides and inside, and a gas hole opened on its upper side; the distance between the edge of the liquid phase extraction component and the sidewall of the reactor is not less than 10% based on 100% of the reactor's inner diameter; the intercepting filter is a non-planar mesh structure, with the lowest point of the intercepting filter located above the catalyst bed and below the liquid phase extraction component, and the highest point of the intercepting filter higher than the liquid phase extraction component, the higher portion passing through the hollow portion of the liquid phase extraction component; a liquid phase feed inlet is provided below the catalyst bed, and a liquid phase reaction product outlet is provided above the reactor; a gas inlet II is provided below the catalyst bed, and a gas outlet is provided above the liquid phase extraction component.

2. The reactor according to claim 1, characterized in that, A pressure regulating valve is installed on the pipeline connected to the gas outlet.

3. The reactor according to claim 1, characterized in that, The catalyst bed is disposed on a catalyst support plate.

4. The reactor according to claim 3, characterized in that, A wire mesh is also provided between the catalyst bed and the catalyst support plate.

5. The reactor according to claim 3, characterized in that, A gas distributor is provided below the catalyst bed and is connected to the gas inlet II.

6. The reactor according to claim 5, characterized in that, The gas distributor is an annular tubular structure with multiple upward-facing gas outlet pipes on the annulus.

7. The reactor according to claim 6, characterized in that, The distance between the gas distributor and the catalyst support plate is 100-800 mm.

8. The reactor according to claim 1, characterized in that, A liquid phase outlet pipe is provided between the liquid phase extraction component and the liquid phase reaction product outlet for outputting the liquid phase reaction products collected by the liquid phase extraction component.

9. The reactor according to claim 8, characterized in that, The liquid phase outlet pipe is connected to at least one of a plurality of interconnected liquid flow channels.

10. The reactor according to claim 8, characterized in that, The diameter of the liquid flow channel and the diameter of the liquid phase outlet pipe satisfy the condition shown in equation (I): N*D1 2 ≥D2 2 Formula (I); In equation (I), N represents the number of liquid flow channels, D1 represents the diameter of the liquid flow channels, and D2 represents the diameter of the liquid phase outlet pipe.

11. A reaction system for synthesizing carbonates, comprising the reactor described in any one of claims 1 to 10.

12. The reaction system according to claim 11, characterized in that, The reaction system includes the reactor and the buffer tank.

13. The reaction system according to claim 12, characterized in that, A buffer material inlet is provided at the upper part of the buffer tank, and the buffer material inlet is connected to the liquid phase reaction product outlet of the reactor; and / or, a buffer material outlet is provided at the bottom of the buffer tank.

14. The reaction system according to claim 12, characterized in that, A gas balance pipe is provided between the buffer tank and the reactor.

15. The reaction system according to claim 13, characterized in that, The buffer tank includes a container and a heat exchanger located in the lower part of the container.

16. The reaction system according to claim 15, characterized in that, The liquid level in the buffer tank is controlled to be above the heat exchanger and below the buffer material inlet.

17. The reaction system according to claim 15, characterized in that, Circulating water is used as the refrigerant for the heat exchanger.

18. The reaction system according to claim 17, characterized in that, Use circulating water at ≥45℃.

19. The reaction system according to claim 17, characterized in that, Circulating water at 50–80℃ is used.

20. The reaction system according to any one of claims 12 to 19, characterized in that, The reaction system includes a mixer, a dissolver, a reactor, a buffer tank, and a circulating pump connected in sequence.

21. The reaction system according to claim 20, characterized in that, The mixer is provided with an alkylene oxide feed inlet; and / or, The solvent is provided with a gas inlet I, and / or, The dissolver is connected to the liquid-phase feed inlet of the reactor; and / or, One end of the circulating pump is connected to the buffer material outlet of the buffer tank, and the other end is connected to the mixer; and / or, A carbonate product outlet is provided between the circulating pump and the mixer.

22. A method for synthesizing carbonates, comprising: Using epoxides and carbon dioxide as raw materials, the raw materials are introduced into the reaction system described in any one of claims 12 to 21 to carry out the reaction, thereby obtaining carbonate products.

23. The method according to claim 22, characterized in that, The method includes the following steps: (1) The epoxy alkane raw material is introduced into the mixer and the dissolver in sequence, and a first stream of carbon dioxide is introduced at the gas inlet I of the dissolver. The first stream of carbon dioxide and the epoxy alkane raw material form a liquid-phase mixed raw material in the dissolver. (2) The liquid-phase mixed raw material is introduced into the reactor through the liquid-phase raw material inlet of the reactor for reaction, and at the same time, a second stream of carbon dioxide is introduced into the reactor through the gas inlet II; (3) In the reactor, the catalyst particles are intercepted by the interception filter and the liquid phase reaction products are collected by the liquid phase extraction component. (4) The collected liquid reaction products enter the buffer tank from the buffer material inlet of the buffer tank and are cooled down. (5) After cooling, the liquid reaction product enters the circulating pump from the buffer material outlet of the buffer tank. Part of the material is circulated by the circulating pump to form circulating material, which enters the mixer and is mixed with the epoxy alkane raw material. Part of the material is collected from the carbonate product outlet to obtain the carbonate product.

24. The method according to claim 23, characterized in that, In step (1), the alkylene oxide feedstock is mixed with the recycled material from step (5) in a mixer, and then flows in parallel with the first stream of carbon dioxide into the solvent; and / or, In step (2), the second stream of carbon dioxide first enters the gas distributor through the gas inlet II, and after being evenly distributed by the gas distributor, it flows in parallel with the liquid-phase mixed raw material into the catalyst bed; and / or, The mass ratio of the first and second streams of carbon dioxide is (0-100):(0-100) and they are not both 0; and / or, In step (5), the recycling ratio is controlled to be 5~20, where the recycling ratio is the weight ratio of the recycled material to the extracted carbonate product.

25. The method according to claim 23, characterized in that, In step (5), the recycling ratio is controlled to be 8~16, where the recycling ratio is the weight ratio of the recycled material to the extracted carbonate product.

26. The method according to any one of claims 22 to 25, characterized in that, The reaction pressure is controlled by a pressure regulating valve at the top of the reactor; and / or, Control the adiabatic temperature rise of the reactor to ≤50℃.

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