A fixed bed for a dimethyl carbonate and ethanol transesterification reaction

Abstract

The utility model relates to a fixed bed for dimethyl carbonate and ethanol ester exchange reaction, including shell, dispersion assembly in the inside of shell, buffer component, catalyst component and catalyst input pipeline and catalyst output pipeline, the catalyst component includes the pivot that rotates and connects in the inside of shell, the connecting seat that sets up on the outer wall of pivot, at least two dispersion type storage components that set up respectively in the upper and lower two sides of connecting seat, catalyst delivery pipeline two for connecting the upper and lower two dispersion type storage components, at least two groups catalyst delivery pipeline three for respectively connecting dispersion type storage component and catalyst input pipeline and dispersion type storage component and catalyst output pipeline of being located below of being located in the upper side. The utility model can change the position of the upper and lower two dispersion type storage components by driving pivot, connecting seat rotation, so that the dispersion type storage component of different positions can realize better contact with reaction liquid, and the solid catalyst is used to the greatest extent.

Description

Technical Field

[0001] This utility model belongs to the field of chemical equipment technology, specifically relating to a fixed bed for the transesterification reaction of dimethyl carbonate and ethanol. Background Technology

[0002] The transesterification reaction of dimethyl carbonate (DMC) with ethanol is an important organic synthesis reaction, widely used in the production of chemicals such as diethyl carbonate. Traditional transesterification reactors mostly use fixed-bed reactors. As shown in the authorized utility model patent CN219291360U, the catalyst in the packing layer is fixedly stored from top to bottom. However, there are still problems in its use. The upper and lower layers of catalyst need to be replaced as a whole. The contact time between the upper and lower layers of catalyst and the reaction liquid is not consistent, which may result in inconsistent levels of loss. Direct replacement of the whole catalyst will cause a certain degree of waste of solid catalyst. Therefore, this application provides a fixed-bed reactor for the transesterification reaction of dimethyl carbonate and ethanol to solve the above-mentioned technical problems. Utility Model Content

[0003] The purpose of this invention is to provide a fixed bed for the transesterification reaction of dimethyl carbonate and ethanol in order to solve the above-mentioned problems. It aims to solve the technical problem in the existing fixed bed technology, where the catalyst in the packing layer is fixed and stored sequentially from top to bottom, and the entire bed is replaced directly when it is replaced. However, this direct replacement of the entire bed will cause a certain degree of waste of solid catalyst.

[0004] This utility model achieves the above objectives through the following technical solutions: A fixed bed for dimethyl carbonate and ethanol transesterification reaction includes a shell, a dispersion component, a buffer component, a catalyst component, a catalyst inlet pipe, and a catalyst outlet pipe disposed inside the shell. The catalyst assembly includes a rotating shaft rotatably connected inside the housing, a connecting seat on the outer wall of the rotating shaft, at least two dispersed storage components respectively located above and below the connecting seat, a catalyst delivery pipe for connecting the upper and lower dispersed storage components, at least two sets of catalyst delivery pipes for respectively connecting the upper dispersed storage component and the catalyst input pipe and the lower dispersed storage component and the catalyst output pipe, and an adjustment component for adjusting the position of the three-phase connection ends of the catalyst input pipe, the catalyst output pipe and the catalyst delivery pipe.

[0005] As a further optimization of this utility model, the distributed storage component includes several columns of catalyst fixing columns, and the width of each column of catalyst fixing columns increases or decreases sequentially from top to bottom. The width changes of adjacent columns of catalyst fixing columns from top to bottom are opposite. Several catalyst delivery pipes are provided between the catalyst fixing columns in each distributed storage component.

[0006] As a further optimization of this utility model, both catalyst delivery pipeline two and catalyst delivery pipeline three are equipped with switch valves.

[0007] As a further optimization of this utility model, the adjustment assembly includes at least two movable seats that are slidably connected to the inner wall of the outer shell and are used to connect to the catalyst input pipe or the catalyst output pipe respectively, a fixed plate fixedly disposed on the top of the outer shell, a movable rod disposed on the top of the movable seat and slidably connected to the fixed plate, and a limiting member for limiting the sliding of the movable rod relative to the fixed plate.

[0008] As a further optimization of this utility model, a dimethyl carbonate inlet pipe and an ethanol inlet pipe are provided on the side wall of the outer shell, and the outlets of the dimethyl carbonate inlet pipe and the ethanol inlet pipe face opposite directions. The dispersion component includes a disc fixed inside the outer shell and several ribs located at the bottom of the disc.

[0009] As a further optimization of this utility model, the buffer assembly includes a buffer tank, a buffer packing material disposed inside the buffer tank, and a plurality of infusion pipes disposed at the bottom of the buffer tank.

[0010] As a further optimization of this utility model, the top of the outer shell is provided with a top pipe and the bottom is provided with a discharge pipe.

[0011] The beneficial effects of this utility model are as follows: This invention can change the position of the upper and lower dispersed storage components by driving the rotating shaft and connecting seat to rotate, so that the dispersed storage components in different positions can achieve good contact with the reaction liquid and make maximum use of the solid catalyst. In this invention, when replacing the solid catalyst, the solid catalyst inside the lower dispersed storage component is first discharged, and then the solid catalyst inside the upper dispersed storage component is transported to the lower dispersed storage component. Then, the vacated upper dispersed storage component is replenished with new solid catalyst. This allows for in-situ alternating catalyst replacement during the reaction process, making the operation convenient. Attached Figure Description

[0012] Figure 1 This is a three-dimensional view of the overall structure of this utility model.

[0013] Figure 2 This is a cross-sectional view of the overall structure of this utility model.

[0014] Figure 3 This is the utility model Figure 2 A sectional view of part of the structure.

[0015] In the diagram: 11. Outer shell; 12. Dimethyl carbonate feed pipe; 13. Ethanol feed pipe; 14. Top pipe; 15. Discharge pipe; 16. Catalyst input pipe; 17. Catalyst output pipe; 21. Disc; 22. Rib; 31. Buffer tank; 32. Infusion pipe; 41. Rotating shaft; 42. Connecting seat; 43. Distributed storage component; 44. Catalyst delivery pipe two; 45. Catalyst delivery pipe three; 51. Moving seat; 52. Moving rod; 53. Fixing plate; 54. Limiting component. Detailed Implementation

[0016] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0017] like Figure 1-3 As shown, a fixed bed for dimethyl carbonate and ethanol transesterification reaction includes a shell 11, a dispersion assembly, a buffer assembly, a catalyst assembly disposed inside the shell 11, a catalyst inlet pipe 16, and a catalyst outlet pipe 17. The catalyst assembly includes a rotating shaft 41 rotatably connected inside the housing 11, a connecting seat 42 disposed on the outer wall of the rotating shaft 41, at least two dispersed storage components 43 respectively disposed above and below the connecting seat 42, a second catalyst delivery pipe 44 for connecting the upper and lower dispersed storage components 43, at least two sets of third catalyst delivery pipes 45 for respectively connecting the upper dispersed storage component 43 and the catalyst input pipe 16 and the lower dispersed storage component 43 and the catalyst output pipe 17, and an adjustment component for adjusting the position of the connection ends of the catalyst input pipe 16 and the catalyst output pipe 17 with the third catalyst delivery pipe 45.

[0018] It should be noted that, in this embodiment, a heater is provided inside the inner wall of the outer shell 11 to facilitate the control of the internal temperature of the outer shell 11; in this embodiment, the catalyst is a solid catalyst.

[0019] Preferably, the distributed storage component 43 includes several columns of catalyst fixing columns, and the width of each column of catalyst fixing columns increases or decreases from top to bottom. The width changes of adjacent columns of catalyst fixing columns from top to bottom are opposite. The purpose of this design is to uniformly disperse the reaction liquid and make the reaction liquid and solid catalyst in better contact. Several catalyst delivery pipes are provided between the catalyst fixing columns in each distributed storage component 43.

[0020] Preferably, both catalyst delivery pipe 2 44 and catalyst delivery pipe 3 45 are equipped with switch valves. When it is not necessary to replace the catalyst in the catalyst fixing column, the switch valves on catalyst delivery pipe 2 44 and catalyst delivery pipe 3 45 are in the closed state to prevent catalyst leakage.

[0021] Preferably, the adjustment assembly includes at least two movable seats 51 that are slidably connected to the inner wall of the outer casing 11 and are used to connect to the catalyst input pipe 16 or the catalyst output pipe 17 respectively; a fixed plate 53 fixedly disposed on the top of the outer casing 11; a movable rod 52 disposed on the top of the movable seat 51 and slidably connected to the fixed plate 53; and a limiting member 54 for limiting the sliding of the movable rod 52 relative to the fixed plate 53. In this embodiment, the top of the movable rod 52 is threaded, and the limiting member 54 is two fixing nuts located on the upper and lower sides of the fixed plate 53 and threadedly connected to the movable rod 52.

[0022] like Figure 2 As shown, when dimethyl carbonate and ethanol undergo transesterification under the action of a solid catalyst, the solid catalyst inside the upper dispersed storage component 43 will first contact dimethyl carbonate and ethanol to promote the transesterification reaction, while the solid catalyst inside the lower dispersed storage component 43 will contact dimethyl carbonate and ethanol later. Its loss will be less than that of the solid catalyst inside the upper dispersed storage component 43. Therefore, a timer can be set to drive the rotating shaft 41 and connecting seat 42 to rotate via a servo motor or a drive source consisting of a servo motor and a reducer, so as to change the position of the upper and lower dispersed storage components 43, so that the dispersed storage components 43 in different positions can achieve better contact with the reaction liquid.

[0023] When the solid catalyst needs to be replaced, the positions of the catalyst input pipe 16 and catalyst output pipe 17 connected to the catalyst delivery pipe 45 can be adjusted using the adjustment components. This allows the catalyst input pipe 16 and catalyst output pipe 17 to be inserted into and fixed to the two catalyst delivery pipes 45, one above the other. First, open the valve on the lower catalyst delivery pipe 45 to allow the solid catalyst inside the two lower distributed storage components 43 to be delivered through the catalyst output pipe 17. Then, close the valve on the lower catalyst delivery pipe 45 and open the valve on the catalyst delivery pipe 44 to allow the solid catalyst inside the two upper distributed storage components 43 to be delivered through the catalyst output pipe 17. The solid catalyst inside the dispersed storage component 43 is sequentially transported to the two dispersed storage components 43 located below. Then, the switch valve on the catalyst delivery pipeline 2 44 is closed and the switch valve on the catalyst delivery pipeline 3 45 located above is opened. New or regenerated solid catalyst is transported to the two dispersed storage components 43 located above through the catalyst input pipeline 16 and the catalyst delivery pipeline 3 45 located above. This allows for in-situ alternating replacement of the solid catalyst during the reaction process, which is convenient to operate. Alternatively, this application can also pause the feeding process and directly replace all the solid catalysts inside the dispersed storage components 43 located above and below, which is also convenient to use.

[0024] Preferably, the outer shell 11 is provided with a dimethyl carbonate inlet pipe 12 and an ethanol inlet pipe 13 on its side wall, and the outlets of the dimethyl carbonate inlet pipe 12 and the ethanol inlet pipe 13 face opposite directions to increase the turbulence of the liquid. The dispersion component includes a disc 21 fixed inside the outer casing 11 and a plurality of ribs 22 located at the bottom of the disc 21.

[0025] Preferably, the buffer assembly includes a buffer tank 31, a buffer packing material disposed inside the buffer tank 31, and a plurality of infusion tubes 32 disposed at the bottom of the buffer tank 31.

[0026] The liquids delivered to the inside of the outer shell 11 through the dimethyl carbonate feed pipe 12 and the ethanol feed pipe 13 converge inside the disc 21. They are further dispersed by colliding with the ribs 22, thus achieving a certain mixing of the two liquids. The mixed liquids fall from the edge of the disc 21. In order to reduce the impact force, they can be buffered by the buffer packing before being delivered downwards through the infusion pipe 32.

[0027] Preferably, the outer shell 11 is provided with a top pipe 14 at the top and a discharge pipe 15 at the bottom.

[0028] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A fixed-bed reactor for transesterification of dimethyl carbonate and ethanol, characterized in that: It includes a housing (11), a dispersion component, a buffer component, a catalyst component, a catalyst inlet pipe (16), and a catalyst outlet pipe (17) disposed inside the housing (11). The catalyst assembly includes a rotating shaft (41) rotatably connected inside the housing (11), a connecting seat (42) on the outer wall of the rotating shaft (41), at least two distributed storage components (43) respectively located above and below the connecting seat (42), a second catalyst delivery pipe (44) for connecting the upper and lower distributed storage components (43), at least two sets of third catalyst delivery pipes (45) for connecting the upper distributed storage component (43) and the catalyst input pipe (16) and the lower distributed storage component (43) and the catalyst output pipe (17) respectively, and an adjustment component for adjusting the position of the connection end between the catalyst input pipe (16) and the catalyst output pipe (17) and the third catalyst delivery pipe (45).

2. A fixed bed for dimethyl carbonate and ethanol transesterification reaction according to claim 1, characterized in that: The distributed storage assembly (43) includes several columns of catalyst fixing columns, and the width of each column of catalyst fixing columns increases or decreases from top to bottom. The width changes of adjacent columns of catalyst fixing columns from top to bottom are opposite. Several catalyst delivery pipes are provided between the catalyst fixing columns in each distributed storage assembly (43).

3. A fixed bed for dimethyl carbonate and ethanol transesterification reaction according to claim 1, characterized in that: Both catalyst delivery pipeline two (44) and catalyst delivery pipeline three (45) are equipped with switch valves.

4. A fixed bed for dimethyl carbonate and ethanol transesterification reaction according to claim 1, characterized in that: The adjustment assembly includes at least two movable seats (51) that are slidably connected to the inner wall of the housing (11) and used to connect to the catalyst input pipe (16) or the catalyst output pipe (17) respectively, a fixed plate (53) fixedly disposed on the top of the housing (11), a movable rod (52) disposed on the top of the movable seat (51) and slidably connected to the fixed plate (53) in the upper and lower directions, and a limiting member (54) for limiting the upper and lower sliding of the movable rod (52) relative to the fixed plate (53).

5. A fixed bed for dimethyl carbonate and ethanol transesterification reaction according to claim 1, characterized in that: The outer shell (11) is provided with a dimethyl carbonate feed pipe (12) and an ethanol feed pipe (13) on its side wall, and the outlets of the dimethyl carbonate feed pipe (12) and the ethanol feed pipe (13) face opposite directions. The dispersion component includes a disc (21) fixed inside the outer shell (11) and a plurality of ribs (22) located at the bottom of the disc (21).

6. A fixed bed for dimethyl carbonate and ethanol transesterification reaction according to claim 1, characterized in that: The buffer assembly includes a buffer tank (31), a buffer packing material disposed inside the buffer tank (31), and several infusion tubes (32) disposed at the bottom of the buffer tank (31).

7. A fixed bed for dimethyl carbonate and ethanol transesterification reaction according to claim 1, characterized in that: The outer shell (11) is provided with a top pipe (14) at the top and a discharge pipe (15) at the bottom.

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