Bubble tower reactor for homogeneous catalytic reaction in carbonic ester production

Abstract

The utility model discloses a bubble tower reactor for homogeneous catalytic reaction in carbonic ester production. The bubble tower reactor mainly comprises a tower shell, a built-in feeding distributor, an outer heat tracing half pipe, a tower tray, an oil collecting tank, a vapor-liquid channel, a gas phase outlet and the like. The method is characterized in that gas-phase materials, liquid-phase materials and a catalyst enter a tower bottom distributor respectively and then are subjected to parallel flow, the gas-liquid mixed materials are subjected to mass and heat transfer homogeneous reaction when penetrating through a sieve plate tray with a specific layer number and a specific hole number, and finally reaction liquid is collected through an oil collecting tank which is arranged at the top of the tower and is of a specific structure. The bubble tower reactor disclosed by the utility model is particularly suitable for occasions with high system pressure, high reaction conversion rate requirement, large operation elasticity requirement and continuous operation. Compared with an existing fixed bed process, the problems that pressure drop of an inlet and an outlet of a fixed bed reactor is large, a tube box flange sealing face is prone to leakage, feeding distribution is uneven, productivity operation elasticity is small, and a catalyst needs to be replaced regularly are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical industry, and specifically relates to a bubbling tower reactor for homogeneous catalytic reaction in carbonate production. Background Art

[0002] At present, in the production process of carbonate esters, fixed bed process and homogeneous catalytic process are usually used to synthesize vinyl carbonate from ethylene oxide or propylene oxide and carbon dioxide. The fixed bed process adopts a vertical shell and tube fixed bed reactor. The reactor tube is filled with catalyst fillers. Ethylene oxide or propylene oxide and carbon dioxide enter from the lower tube box and react after passing through the catalyst fillers. Due to the shell and tube structure, the primary problem of the fixed bed reactor is that the pressure difference between the lower and upper tube boxes at the inlet and outlet is relatively large. Even due to the unreasonable selection of fillers in the tubes, the inlet tube box may be pressurized, resulting in the safety risk of pressure overload failure of the tube sheet, tube bundle and tube box. Secondly, the materials entering from the tube box are prone to uneven distribution after entering the tubes due to pressure fluctuations, fluid impact and other reasons, and the catalytic reaction of the materials in the tubes in each zone is uneven. Furthermore, if the fixed bed reactor wants to increase its production capacity, it can only increase the equipment diameter or lengthen the tube length. The current shell and tube heat exchanger standard GB / T151-2014 stipulates that the nominal diameter of shell and tube equipment shall not exceed 4000mm, and the equipment with an over-limit diameter will face many difficulties in sealing, hoisting and transportation. When choosing to lengthen the tube length, the over-long tube will inevitably further increase the pressure difference, thereby limiting the development of large-scale equipment and low production capacity flexibility. At the same time, the catalyst packing in the fixed bed reactor tube bundle gradually fails after a certain period of circulation, and the packing needs to be replaced regularly, affecting the continuity of operation. Utility Model Content

[0003] The utility model aims to provide a bubbling tower reactor for homogeneous catalytic reaction in the process of synthesizing carbonate. The bubbling tower reactor of the utility model has a simple and reasonable structure, is easy to maintain, can be used for high-pressure processes, and the equipment can be large-scale. Moreover, the homogeneous catalytic conversion rate is close to 100%, the reaction conditions are mild, and only part of the catalyst needs to be intermittently supplemented to the reaction system, which does not affect the continuity of production.

[0004] The technical solution of this utility model:

[0005] A bubbling tower reactor for homogeneous catalytic reaction in carbonate production mainly consists of a tower shell, a built-in gas-phase feed distributor, a built-in liquid-phase feed distributor, an external heating half-pipe, a tower plate, an oil collecting tank, a vapor-liquid channel and a gas phase outlet. The built-in gas-phase feed distributor is arranged on the bottom cylinder of the tower, the built-in liquid-phase feed distributor is arranged on the bottom head of the tower, the heating half-pipe is arranged on the outer surface of the tower body between the bottom gas inlet and the first layer of the tower plate at the bottom of the tower, the tower plate is arranged in sections at fixed intervals in the tower, the oil collecting tank is arranged on the top cylinder of the tower, and the gas phase outlet is arranged on the top head of the tower. The gas and liquid phases of the materials from the bottom of the tower flow through the tower plate to fully react, and the generated reaction liquid overflows into the oil collecting tank.

[0006] The homogeneous catalytic reaction bubbling tower reactor is used for carbonate production.

[0007] The gas phase feed distributor is composed of a main pipe and several branch pipes, and circular holes are opened on the main pipe and the branch pipe.

[0008] The built-in liquid phase feed distributor is a box-type distributor, the front of the distributor is a circular hole plate, and the side is a rectangular hole plate.

[0009] The tower plate is a sieve plate tower plate, which is detachable and can be installed in and out of a manhole; circular holes are opened on the tower plate, and the size and number of the holes are calculated based on the reaction amount.

[0010] The oil collecting tank adopts an inner jacket structure, the lower end of the inner jacket is sealed with the tower body, and the upper end is equipped with a lift cylinder as an overflow port; the liquid material outlet of the reactor is arranged on the tower body at the lower end of the inner jacket.

[0011] The gas-liquid channel is arranged on the top of the oil collecting tank and is composed of a number of air risers with equal or unequal diameters and a conical cover.

[0012] The bubbling tower reactor is a vertical tower container with a skirt. The reactor pressure is relatively high, and the maximum allowable working pressure reaches 3.0~10MPa(G). Because the calculated thickness of the equipment cylinder wall under the internal pressure condition is proportional to the inner diameter of the container, it is more material-saving to increase the height of the cylinder under the same volume. The tower cylinder structure adopts a continuous cylinder welding structure, and there is no oversized container flange sealing structure of the shell and tube reactor tube box, so there is no problem of leakage of highly toxic media on the container flange sealing surface. Carbonate production lines generally have requirements for anti-iron ion pollution, and the material of the equipment body must be stainless steel. Because the reactor pressure is high and the shell is thick, it is more cost-effective to use carbon steel-stainless steel composite plates with lower material prices than stainless steel.

[0013] The built-in gas phase feed distributor is used to distribute the gas phase material more evenly. The distributor adopts a main pipe plus branch pipe structure, the branch pipes are distributed on both sides of the main pipe, the length of the branch pipes covers the entire cylinder cross section according to the inner diameter of the equipment, and small holes are evenly distributed on the main pipe and the branch pipes, and the holes are facing upward or obliquely upward.

[0014] The built-in liquid phase feed distributor is not only used to distribute the liquid phase material more evenly but also acts as an anti-collision plate. The distributor adopts a box-type structure, with a small hole on the front of the fluid inlet and a rectangular hole on the side.

[0015] The outer heat tracing half pipe is used to increase the temperature in the initial stage of the reaction to accelerate the reaction speed. The half pipe of the outer wall of the cylinder can be made of carbon steel, equidistantly spirally wound on the outer wall of the cylinder, and welded to the cylinder wall by double-sided continuous welding. Steam heating is passed inside, and the condensate can be completely discharged.

[0016] The tower tray is a sieve plate tray, which is used to increase the surface area of ​​gas-liquid combination when gas and liquid pass through, so as to fully react. When the diameter of the tower tray is large, a main beam support should be set. The tower tray should be removable on both sides and can be installed and replaced through the manhole on the tower wall. The tower tray is made of stainless steel, and the openings on the tower tray and the number of tower tray layers are calculated and determined according to the size of the material reaction amount.

[0017] The oil collecting tank is arranged at the top of the tower to collect the overflowed reaction liquid. The oil collecting tank adopts an overflow structure of an inner jacketed cylinder and a riser pipe. After the reaction is completed, the overflowed reaction liquid is collected in the annular interlayer. The inner jacketed cylinder must meet the strength requirements of the static pressure of the liquid column and the rigidity requirements of the structure.

[0018] The vapor-liquid channel is used to separate vapor and liquid materials, and the height of the gas riser should be higher than the height of the liquid phase material in the tower bottom.

[0019] The gas phase outlet is provided with a wire mesh demister for removing liquid droplets entrained by the gas phase.

[0020] The bubble tower reactor for homogeneous catalytic reaction using the above technical solution can meet the process requirements for the production of ethylene carbonate, an electrolyte solvent for lithium batteries. It not only has uniform reaction, high reaction efficiency, and safe and reliable equipment, but can also be expanded for production by increasing the tower height or increasing the diameter according to production capacity requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The schematic diagram of the reactor structure of the utility model is

[0022] Figure 2 Schematic diagram of the opening of the tower plate of the utility model

[0023] Figure 3 Schematic diagram of the gas distributor of the utility model

[0024] As shown in the figure: 1-liquid phase feed port, 2-liquid phase feed distributor, 3-gas phase feed distributor, 4-heating half pipe, 5-tower tray, 6-reaction liquid discharge port, 7-oil collecting tank, 8-vapor-liquid channel, 9-wire mesh demister, 10-gas outlet, 11-upper head, 12-tower top hanging column, 13-cylinder, 14-manhole, 15-steam inlet, 16-condensate outlet, 17-gas phase feed port, 18-lower head, 19-skirt, 20-anchor bolt seat DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with specific examples, but the present invention is not limited to the following examples. Without departing from the scope of the aforementioned purpose, the implementation of changes should be included in the technical scope of the present invention.

[0026] The bubbling tower reactor for homogeneous catalytic reaction in carbonate production mainly consists of a tower shell, a built-in gas-phase feed distributor, a built-in liquid-phase feed distributor, an external heating half-pipe, a tower plate, an oil collecting tank, a vapor-liquid channel and a gas phase outlet. The built-in gas-phase feed distributor is arranged on the bottom cylinder of the tower, the built-in liquid-phase feed distributor is arranged on the bottom head of the tower, the heating half-pipe is arranged on the outer surface of the tower body between the bottom gas inlet and the first layer of the tower plate at the bottom of the tower, the tower plate is arranged in sections at a fixed interval in the tower, the oil collecting tank is arranged on the top cylinder of the tower, and the gas phase outlet is arranged on the top head of the tower. The gas and liquid phases of the materials flow from the bottom of the tower through the tower plate to fully react, and the generated reaction liquid overflows into the oil collecting tank.

[0027] Take a bubbling tower reactor as an example: the inner diameter of the equipment is Φ3600mm, the tower body height is 26000mm, the skirt height is 4000mm, the volume is 277.67m³, and the container category is Class III. The main body of the shell is made of S31603 (solid solution) + Q345R (normalizing) composite plate of NB / T47002.1-2019, the nominal thickness of the cylinder composite plate is 4+46mm, and the minimum forming thickness of the standard elliptical head composite plate is 4+45.3mm. The total metal mass of the equipment is 152750kg, of which the composite plate mass is 126060kg. The gas phase distributor and liquid phase distributor are set at the bottom of the tower, the wire mesh demister is set at the top of the tower, and the tower tray is provided with 5 layers, and the openings on each layer of the tower tray are arranged in an equilateral triangle. The inner diameter of the oil collecting tank cylinder is Φ2500mm, the height is 2300mm, and the height of the gas riser is 550mm. The bubble tower reactor for homogeneous catalytic reaction that meets the above parameters runs smoothly, reacts evenly, and operates continuously. According to the needs of production capacity, the tower height can be increased or the tower diameter can be increased for expansion, and the equipment operation flexibility is large.

Claims

1. A bubbling tower reactor for homogeneous catalytic reaction of carbonate production, mainly composed of a tower shell, a built-in gas-phase feed distributor, a built-in liquid-phase feed distributor, an external heating half-pipe, a tower plate, an oil collecting tank, a vapor-liquid channel and a gas phase outlet, wherein the built-in gas-phase feed distributor is arranged on the tower bottom cylinder, the built-in liquid-phase feed distributor is arranged on the tower bottom head, the heating half-pipe is arranged on the tower body between the tower bottom gas inlet and the first tower plate at the bottom of the tower, the tower plates are arranged in sections at fixed intervals in the tower, the oil collecting tank is arranged on the tower top cylinder, and the gas phase outlet is arranged on the tower top head, characterized in that The materials flow from the gas and liquid phases at the bottom of the tower through the tower plates for full reaction, and the generated reaction liquid overflows into the oil collecting tank.

2. The bubbling column reactor for homogeneous catalytic reaction of carbonate production according to claim 1, characterized in that: The reactor is a vertical tower container.

3. The bubble column reactor for homogeneous catalytic reaction of carbonate production according to claim 1, characterized in that: The reactor body is made of a carbon steel-stainless steel composite plate.

4. The bubble column reactor for homogeneous catalytic reaction of carbonate production according to claim 1, characterized in that: The gas phase feed distributor is composed of a main pipe and several branch pipes, and circular holes are opened on the main pipe and the branch pipe.

5. The bubble column reactor for homogeneous catalytic reaction of carbonate production according to claim 1, characterized in that: The built-in liquid phase feed distributor is a box-type distributor, the front of the distributor is a circular hole plate, and the side is a rectangular hole plate.

6. The bubble column reactor for homogeneous catalytic reaction of carbonate production according to claim 1, characterized in that: The heat tracing half pipe is heated by steam, and the steam enters from the top and exits from the bottom.

7. The bubble column reactor for homogeneous catalytic reaction of carbonate production according to claim 1, characterized in that: The tower plate is a sieve plate tower plate, which is detachable and can be installed through a manhole; circular holes are opened on the tower plate, and the size and number of the holes are calculated based on the reaction amount.

8. The bubble column reactor for homogeneous catalytic reaction of carbonate production according to claim 1, characterized in that: The oil collecting tank adopts an inner jacket structure, the lower end of the inner jacket is sealed with the tower body, and the upper end is equipped with a lift cylinder as an overflow port; the liquid material outlet of the reactor is arranged on the tower body at the lower end of the inner jacket.

9. The bubble column reactor for homogeneous catalytic reaction of carbonate production according to claim 1, characterized in that: The gas-liquid channel is arranged on the top of the oil collecting tank and is composed of a number of air risers with equal or unequal diameters and a conical cover.

10. The bubble column reactor for homogeneous catalytic reaction of carbonate production according to claim 1, characterized in that: The gas phase outlet is filtered by a wire mesh demister.

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