Preheating type axial methanol synthesis reactor
By designing a preheated axial structure in the methanol synthesis reactor, the reaction gas is heated using waste heat to make its temperature consistent with the catalyst layer temperature, the problem of increased side reactions when the reaction gas and the catalyst are initially in contact, and the reaction efficiency of the reactor is improved.
Patent Information
- Application Number
- CN202421035753.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-14
- Publication Date
- 2025-03-28
- Estimated Expiration
- 2034-05-14
AI Technical Summary
In the existing methanol synthesis reactor, the side reactions of the reaction gas during initial contact with the catalyst increase, resulting in a decrease in the overall reaction efficiency of the reactor.
A preheated axial methanol synthesis reactor is designed, and the reaction gas before entering the catalyst layer is heated using the waste heat in the reactor to make its temperature consistent with the catalyst layer temperature, thereby reducing the side reaction between the reaction gas and the catalyst.
By heating the reaction gas, side reactions are effectively reduced and the chemical reaction efficiency of the reactor is improved.
Smart Images
Figure CN222678062U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a chemical device, in particular to a methanol synthesis reactor, specifically a preheating type axial methanol synthesis reactor. Background Art
[0002] In the chemical industry, methanol, as an important chemical raw material, has a wide range of application value and plays an important role in the fields of medicine, organic synthesis, coatings, etc. Synthetic methanol has become an important industry in the chemical industry due to its low production cost and wide range of uses. Its working principle is to generate methanol by synthesizing carbon monoxide, carbon dioxide and hydrogen under high pressure and low temperature conditions.
[0003] At present, the most widely used methanol synthesis process in the market is the Lurgi low-pressure process. The methanol reactor adopts a shell-and-tube reactor, the catalyst is installed in the tube, the reaction heat is removed by the boiling water between the tubes, and high-pressure steam is generated. The operating temperature of this process is 250~260℃ and the pressure is 5~6MPa. There are fewer side reactions during the reaction process and the time-space yield is high.
[0004] However, the reactor in this process has the following defects: the temperature of the raw gas at the reactor inlet (about 220°C) is much lower than the temperature of the catalyst bed in the reactor (about 250°C), which leads to an increase in side reactions during the initial contact between the reaction gas and the catalyst, reducing the overall reaction efficiency of the reactor.
[0005] Therefore, improvements are needed to increase the chemical reaction efficiency of the reactor. Utility Model Content
[0006] The purpose of the utility model is to provide a preheating type axial methanol synthesis reactor in view of the deficiencies in the prior art, which can make full use of the waste heat in the reactor to heat the reaction gas before entering the catalyst layer, so that its temperature tends to be consistent with the temperature of the catalyst layer, reduce the side reactions between the reaction gas and the catalyst, and improve the chemical reaction efficiency of the reactor.
[0007] The technical solution of the utility model is:
[0008] A preheating type axial methanol synthesis reactor comprises a cylinder,
[0009] The cylinder is in the shape of a vertical cylinder, with its upper and lower ends both open and connected to the upper and lower heads respectively; the lower head is provided with a reaction gas outlet and a discharge port;
[0010] It also includes an air inlet pipe, which is installed through the upper head;
[0011] It also includes an upper tube plate and a lower tube plate, which are respectively installed at the upper and lower ends of the cylinder, so that a closed heat exchange cavity is formed inside the cylinder; a heat exchange inlet and a heat exchange outlet are provided on the side wall of the heat exchange cavity, so that the heat exchange medium can be input into and output from the heat exchange cavity;
[0012] It also includes a plurality of reaction tubes, the upper and lower ends of which are respectively connected to the upper tube plate and the lower tube plate, and a catalyst is arranged inside the reaction tubes;
[0013] It also includes a heat exchange tube assembly; the heat exchange tube assembly includes an outer tube and an inner tube, both of which are straight tubes; the outer tube is arranged in the heat exchange cavity, the upper end of which is connected with the upper tube plate, and the lower end of which is closed; the inner tube is arranged in the outer tube, the upper end of which extends out of the upper tube plate and is connected with the air intake pipe, and the lower end of which is adjacent to the lower end of the outer tube; a gap is provided between the inner tube and the outer tube.
[0014] Furthermore, the upper head and the lower head are both dome-shaped, with their openings facing the interior of the cylinder.
[0015] Furthermore, the air inlet pipe is centrally arranged on the upper head; the discharge port is centrally arranged on the lower head; and the reaction gas outlet is located on the side of the lower head.
[0016] Furthermore, a manhole is provided on the upper head.
[0017] Furthermore, the diameter of the air intake pipe is greater than the diameter of the inner pipe.
[0018] Furthermore, there are multiple heat exchange tube assemblies, which are evenly distributed around the central axis of the cylinder.
[0019] Furthermore, the lower end of the outer tube is connected to the lower tube plate.
[0020] Furthermore, the heat exchange inlet and the heat exchange outlet are respectively located at the lower end and the upper end of the side wall of the heat exchange chamber.
[0021] Furthermore, the heat exchange medium is saturated water.
[0022] Beneficial effects of the utility model:
[0023] The utility model has reasonable design, simple structure and convenient implementation. It can make full use of the waste heat in the reactor to heat the reaction gas before entering the catalyst layer so that its temperature tends to be consistent with the temperature of the catalyst layer. Therefore, it can effectively reduce the side reactions between the reaction gas and the catalyst and improve the chemical reaction efficiency of the reactor. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a structural schematic diagram of the utility model.
[0025] Figure 2 This is a schematic diagram of the connection between the heat exchange tube assembly and the gas collecting pipe when there are multiple groups.
[0026] Figure 3 yes Figure 2 Middle AA section view.
[0027] Among them, 1-manhole; 2-inner tube; 3-upper tube plate; 4-outer tube; 5-cylinder; 6-heat exchange inlet; 7-reaction gas outlet; 8-discharging port; 9-lower head; 10-lower tube plate; 11-reaction tube; 12-catalyst; 13-heat exchange outlet; 14-upper head; 15-inlet pipe. DETAILED DESCRIPTION
[0028] The utility model is further described below in conjunction with the accompanying drawings and embodiments.
[0029] like Figure 1 shown.
[0030] The utility model discloses a preheating type axial methanol synthesis reactor, which comprises a cylinder 5, a heat exchange tube assembly, a reaction tube 11 and the like.
[0031] The cylinder body 5 is in the shape of a vertical cylinder, the upper and lower ends of which are open and connected to the upper head 14 and the lower head 9 respectively.
[0032] The upper head 14 and the lower head 9 are both in the shape of dome shells, and their openings face the inside of the cylinder 5 to facilitate the collection of gas and the like.
[0033] The upper end cap 14 is provided with an air inlet pipe 15 for introducing the reaction gas. At the same time, the upper end cap 14 is also provided with a manhole 1 for convenient entry of personnel for maintenance or filling of catalysts. Preferably, the air inlet pipe 15 is centrally arranged. The manhole 1 is located at the side.
[0034] The lower end cap 9 is provided with a reaction gas outlet 7 and a discharge port 8. The discharge port 8 is centrally arranged to facilitate the discharge of the catalyst. The reaction gas outlet 7 is located at the side.
[0035] The upper and lower ends of the cylinder 5 are provided with an upper tube sheet 3 and a lower tube sheet 10, respectively. The upper tube sheet 3 and the lower tube sheet 10 are both flat plates, and the two ends of the cylinder 5 can be closed to form a closed heat exchange cavity inside the cylinder 5. The lower and upper ends of the side wall of the heat exchange cavity are provided with a heat exchange inlet 6 and a heat exchange outlet 13, respectively, so that the heat exchange medium can be input and output therefrom, and the heat exchange medium can flow through the heat exchange cavity from bottom to top. Preferably, the heat exchange medium is saturated water.
[0036] The heat exchange tube assembly includes an outer tube 4 and an inner tube 2, both of which are straight tubes. The outer tube 4 is arranged in the heat exchange cavity, and its upper end is connected to the upper tube plate 3, and its lower end is closed and connected to the lower tube plate 10. The outer diameter of the inner tube 2 is smaller than the inner diameter of the outer tube 4, and is placed inside the outer tube 4, so that there is a gap between the inner tube 2 and the outer tube 4. The length of the inner tube 2 is greater than that of the outer tube 4, and its upper end extends out of the upper tube plate 3 and is connected to the air inlet pipe 15, and its lower end is adjacent to the lower end of the outer tube 4.
[0037] Further, such as Figure 2 and 3 As shown, there are multiple heat exchange tube assemblies, which are evenly distributed around the central axis of the cylinder 5. At the same time, the diameter of the air inlet pipe 15 is larger than the diameter of the inner pipe 2, so that all the inner pipes can be connected to the end of the air inlet pipe 15. The number of heat exchange tube assemblies can be calculated based on the production capacity and heat exchange capacity of the device.
[0038] The reaction tubes 11 are multiple and straight tube-shaped, arranged in the heat exchange cavity and evenly distributed in the area outside the heat exchange tube assembly. The upper and lower ends of the reaction tube 11 are respectively connected to the upper tube plate 3 and the lower tube plate 10, and a catalyst is arranged inside. Preferably, a hollow baffle is arranged at the lower end of the reaction tube to prevent the catalyst from falling out. At the same time, it can ensure the smooth passage of gas.
[0039] The working process of the utility model is:
[0040] First, the catalyst 6 is loaded into the reaction tube through the manhole.
[0041] Subsequently, saturated water at a temperature of about 250°C is input from the heat exchange inlet and made to flow out from the heat exchange outlet, so that the heat exchange cavity is filled with saturated water, and the reaction tube and the outer tube in the heat exchange tube assembly are immersed in the saturated water.
[0042] During production, the reaction gas with a temperature of about 220°C is fed into the inner tube from the air inlet pipe, flows out from the lower end of the inner tube, flows out of the outer tube through the gap between the inner tube and the outer tube, and enters the upper head. During this period, the reaction gas can heat up with saturated water, so that its temperature tends to be consistent with the temperature of the catalyst layer.
[0043] Then, the reaction gas is dispersed by the upper head and flows into the reaction tube, contacts with the catalyst for reaction, flows out from the lower end of the reaction tube and enters the lower head, and finally flows out from the reaction gas outlet and enters the next process.
[0044] During the reaction between the reaction gas and the catalyst, heat is generated, which can be taken away by heat exchange with saturated water, ensuring that the temperature of the catalyst is in a state suitable for the catalytic reaction. At the same time, the saturated water partially vaporizes after absorbing heat, which reduces its density and increases, and flows out of the cylinder through the heat exchange outlet, and then separates the gas in it through the external gas-liquid separator, and then flows into the cylinder again through the heat exchange inlet to achieve circulation.
[0045] The utility model can make full use of the waste heat in the reactor to heat the reaction gas before entering the catalyst layer so that its temperature tends to be consistent with the temperature of the catalyst layer, thereby effectively reducing the side reactions between the reaction gas and the catalyst and improving the chemical reaction efficiency of the reactor.
[0046] The parts not involved in the present invention are the same as the prior art or can be implemented by using the prior art.
Claims
1. A preheating axial methanol synthesis reactor, comprising a cylinder, characterized in that: The cylinder is in the shape of a vertical cylinder, with its upper and lower ends both open and connected to the upper head and the lower head respectively; the lower head is provided with a reaction gas outlet and a discharge port; and also includes an air inlet pipe, which is installed through the upper head; It also includes an upper tube plate and a lower tube plate, which are respectively installed at the upper and lower ends of the cylinder, so that a closed heat exchange cavity is formed inside the cylinder; a heat exchange inlet and a heat exchange outlet are provided on the side wall of the heat exchange cavity, so that the heat exchange medium can be input into and output from the heat exchange cavity; It also includes a plurality of reaction tubes, the upper and lower ends of which are respectively connected to the upper tube plate and the lower tube plate, and a catalyst is arranged inside the reaction tubes; It also includes a heat exchange tube assembly; the heat exchange tube assembly includes an outer tube and an inner tube, both of which are straight tubes; the outer tube is arranged in the heat exchange cavity, the upper end of which is connected with the upper tube plate, and the lower end of which is closed; the inner tube is arranged in the outer tube, the upper end of which extends out of the upper tube plate and is connected with the air intake pipe, and the lower end of which is adjacent to the lower end of the outer tube; a gap is provided between the inner tube and the outer tube.
2. The preheating type axial methanol synthesis reactor according to claim 1 is characterized in that: The upper head and the lower head are both in a dome-shaped shell shape, and their openings face the interior of the cylinder.
3. The preheating type axial methanol synthesis reactor according to claim 1 is characterized in that: The air inlet pipe is centrally arranged on the upper end cover; the discharge port is centrally arranged on the lower end cover; and the reaction gas outlet is located on the side of the lower end cover.
4. The preheating type axial methanol synthesis reactor according to claim 1 is characterized in that: The upper cover is provided with a manhole.
5. The preheating type axial methanol synthesis reactor according to claim 1 is characterized in that: The diameter of the air inlet pipe is greater than the diameter of the inner pipe.
6. The preheating type axial methanol synthesis reactor according to claim 1 is characterized in that: There are multiple heat exchange tube assemblies, which are evenly distributed around the central axis of the cylinder.
7. The preheating type axial methanol synthesis reactor according to claim 1 is characterized in that: The lower end of the outer tube is connected to the lower tube plate.
8. The preheating type axial methanol synthesis reactor according to claim 1 is characterized in that: The heat exchange inlet and the heat exchange outlet are respectively located at the lower end and the upper end of the side wall of the heat exchange cavity.
9. The preheating type axial methanol synthesis reactor according to claim 1, characterized in that: The heat exchange medium is saturated water.