CN108654523B

CN108654523B - Filling structure of tube reactor catalyst

Info

Publication number: CN108654523B
Application number: CN201810622792.4A
Authority: CN
Inventors: 陈风敬; 商宽祥; 卢文新
Original assignee: China Wuhuan Engineering Co Ltd
Current assignee: China Wuhuan Engineering Co Ltd
Priority date: 2018-06-15
Filing date: 2018-06-15
Publication date: 2023-10-13
Anticipated expiration: 2038-06-15
Also published as: CN108654523A

Abstract

The invention relates to a filling structure of a catalyst in a tubular reactor, which solves the problems of large volume, inconvenient maintenance operation and uneven temperature control in the reactor of the existing filling structure. The technical scheme includes that the reactor comprises a plurality of reaction tubes, each reaction tube is divided into two filling areas, namely an area A filled with a solid catalyst and an area B filled with an inert component, and the filling areas of two adjacent reaction tubes from a raw material inlet to a raw material outlet are opposite. The invention has simple structure, simple and convenient operation, easy control of reaction temperature, difficult sintering, long catalyst regeneration period, small reactor volume and low production cost.

Description

Filling structure of tube reactor catalyst

Technical Field

The invention relates to a tubular reactor, in particular to a filling structure of a tubular reactor catalyst.

Background

Isothermal tube reactors are often used in chemical production devices, the reactors are similar to tube heat exchangers, catalysts are placed in tubes, molten salts or water vapor, heat conducting oil and the like are introduced between the tubes as heat removal media, reaction materials react through catalyst layers in the tubes, and reaction heat is carried out through the tube walls and heat removal media exchange. As shown in FIG. 1, the temperature distribution in the heat exchange type tube reactor from the raw material inlet to the product outlet, the temperature increases and decreases as the reaction proceeds, and a highest point T exists _{Highest to} (i.e., hot spot temperature). When a plurality of tubes are arranged in the reactor in parallel, hot spots are mutually reinforced due to the mutual influence among the tubes, and the reaction temperature is higher. Therefore, the biggest difficulty of the reactor is that the temperature is difficult to control evenly, especially for strong exothermic reaction, the reaction materials are easy to react violently in the local area of the catalyst, so that the local temperature in the reactor is too high, the problems of cracking of raw materials or products, coking of the catalyst, blocking of pipes and the like are caused, and the application of the reactor is severely limited.

In order to solve the technical problems, a filling mode of a catalyst in a reactor tube array is modified, for example, patent document 201310033770.1 discloses a filling method of a catalyst in a butene oxidative dehydrogenation isothermal reactor, and mainly solves the problems of overhigh local temperature of the reactor tube array, low butadiene selectivity and short catalyst carbon deposition and regeneration period in the butene oxidative dehydrogenation tube array isothermal reactor technology in the prior art. The reactor is a tubular isothermal reactor, the tubular is filled with a mixture of catalyst A and catalyst B, wherein the catalyst A is a high-activity catalyst, the catalyst B is a low-activity catalyst or an inert material, when the catalyst is filled, the content of the catalyst A in different filling areas from an inlet to an outlet of the tubular reactor is gradually increased, and the content of the catalyst B is gradually reduced. Although this packing approach can solve the problem of local overheating of the reaction temperature, the following problems remain: (1) Because the agent B is mixed in different areas in the tube, the number, the length or the diameter of the reaction tubes are required to be greatly increased in order to realize the same catalytic effect, so that the volume of the reactor is increased, and the manufacturing cost and the installation difficulty are increased; (2) The mixed loading of a plurality of areas with different proportions can greatly increase the loading difficulty and is not easy to control. (3) Because the filling sequence and the filling mode of each reaction tube are the same, the problem of mutual reinforcement among hot spots exists in theory.

Disclosure of Invention

The invention aims to solve the technical problems and provide a tubular reactor catalyst filling structure which has the advantages of simple structure, simple and convenient operation, easy control of reaction temperature, difficult sintering, long catalyst regeneration period, small reactor volume and low production cost.

The filling structure comprises a plurality of reaction tubes, each reaction tube is divided into two filling areas, namely an area A filled with a solid catalyst and an area B filled with an inert component, and the filling areas of two adjacent reaction tubes from a raw material inlet to a raw material outlet are opposite.

The length of the B area tube in the reaction tube is more than 50 mm.

In the same reaction tube, the tube length ratio of the zone A to the zone B is 5-15:1.

The inert component filled in the zone B is at least one of alumina porcelain balls, silica gel, diatomite, ceramic or heat-resistant metal.

Aiming at the problems in the background art, on the premise of introducing inert components as fillers, the inventor changes the thinking mode, and does not adopt mixed loading, but divides each reaction tube into two loading areas, respectively loads solid catalyst and inert components, and then loads the A area and the B area of the adjacent two reaction tubes in a staggered way, thereby having the following advantages: (1) The hot spot areas of two adjacent reaction tubes are also dislocated by dislocation filling, so that the problem of mutual reinforcement between hot spots is avoided, the mutual influence between the reaction tubes in the reactor is reduced, the temperature in the reactor is uniform, and the phenomenon of temperature runaway is prevented, thereby preventing the sintering of the catalyst, prolonging the service life of the catalyst and improving the economic benefit; (2) The heat transfer load of the cooling medium is smoothed, and the excessive concentration of the hot spot foaming range can be effectively prevented; (3) Although the reaction tube is divided into two filling areas, the inventor does not mix the two fillers, so that the filling and maintenance are easy, the operation difficulty is low, and the calculation of the hot spot area of the reaction tube is convenient; (4) Compared with the filling material mixing in the background technology, the filling structure of the invention can reduce the volume of the reactor and the length of the reaction tube, thereby being beneficial to saving space and reducing manufacturing and maintenance costs. (5) The filling of the inert components in the zone B can be used as a support for filling the solid catalyst in the zone A, so that the catalyst is convenient to fill.

Further, the tube length of the zone B is preferably more than 50mm, the ratio of the tube lengths of the zone A and the zone B is 5-15:1, the volume of the reaction tube is wasted when the reaction tube is too large, and the effect of hot spot dislocation cannot be achieved when the reaction tube is too small.

The invention has the advantages of simple structure, easy operation and maintenance, low manufacturing cost, easy control of reaction temperature, difficult sintering and long catalyst regeneration period, and compared with the scheme in the background art, the invention also has the advantages of saving the use amount of inert components (B agent), reducing the height of the reactor, reducing the volume of the reactor and improving the filling speed, and is particularly suitable for a tubular reactor.

Drawings

FIG. 1 is a graph showing the temperature profile of a prior art heat exchange type tube reactor.

FIG. 2 is a schematic diagram of the structure of the present invention.

Fig. 3 is a schematic view of a first pipe arrangement mode.

Fig. 4 is a schematic diagram of a second piping arrangement.

Wherein, the reaction tube 1-is 1.1-first reaction tube, the reaction tube 1.2-second reaction tube, the zone 3-A, the zone 4-B, the solid catalyst 5-and the inert component 6-are arranged in the reaction tube 1-first reaction tube and the reaction tube 1.2-second reaction tube.

Detailed Description

The invention is further explained below with reference to the drawings:

the shell-and-tube reactor is provided with a plurality of reaction tubes 1, each reaction tube 1 is divided into two filling areas, namely an A area 3 filled with a solid catalyst 5 and a B area 4 filled with an inert component 6, and the filling areas of two adjacent reaction tubes 1 from a raw material inlet to a raw material outlet are opposite. Taking fig. 2 as an example, raw materials are introduced into a plurality of reaction tubes from top to bottom, two adjacent reaction tubes are respectively defined as a first reaction tube 1.1 and a second reaction tube 1.2, the upper section of the first reaction tube 1.1 is a zone B3, inert components 6 are filled, the lower section is a zone A, and solid catalysts 5 are filled. The upper section of the second reaction 1.1 is a zone A filled with a solid catalyst 5, and the lower section is a zone B3 filled with an inert component 6. In the same reaction tube, the tube length ratio h1/h2 of the zone A and the zone B is 5-15:1. The kind of the solid catalyst 5 is reasonably selected according to the raw materials to be catalyzed, which is not limited herein, and the inert component 6 may be at least one of alumina porcelain balls, silica gel, diatomaceous earth, ceramics or heat-resistant metals. The temperature profiles of the first reaction tube 1.1 and the second reaction tube 1.2 are shown in fig. 2 at the same time, and it can be seen from the figure that the hot spot areas in the temperature profiles of the two reaction tubes are just staggered, so that the temperature in the reactor is more uniform.

The tube arrangement mode of the multiple reaction tubes in the tube array reactor can be reasonably designed according to the requirement, as shown in a first tube arrangement mode in fig. 3, wherein the filling structures of the catalysts in two adjacent rows of reaction tubes are opposite, as shown in a second tube arrangement mode in fig. 4, and wherein the filling structure of any one reaction tube is opposite to that of the adjacent reaction tube. Other tube layout designs are also possible by those skilled in the art.

Claims

1. The filling structure of the tubular reactor catalyst comprises a plurality of reaction tubes, and is characterized in that each reaction tube is divided into two filling areas, namely an area A filled with a solid catalyst and an area B filled with an inert component, and the filling areas of two adjacent reaction tubes from a raw material inlet to a raw material outlet are opposite.

2. The packing structure of a tubular reactor catalyst according to claim 1, wherein the tube length in zone B is 50mm or more.

3. The packing structure of a tubular reactor catalyst as set forth in claim 1 or 2, wherein the ratio of the tube lengths of the a zone and the B zone in the same reaction tube is 5 to 15:1.

4. The packing structure of the shell-and-tube reactor catalyst according to claim 1 or 2, wherein the inert component packed in the zone B is at least one of silica gel, diatomaceous earth, ceramic or heat-resistant metal.