JP2013082677A - Multi-tubular fixed bed reactor for production of propylene oxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-tubular fixed bed reactor for propylene oxide, which has improvements in whole body size, is made to have a shorter diameter and a thinner wall thickness, saves investment, and can be further adjusted to production efficiency required.SOLUTION: The multi-tubular fixed bed reactor for the production of propylene oxide includes a reactor shell, an inlet port for reaction gas, an outlet port for reaction gas, an inlet port for liquid, an outlet port for liquid, a reaction tube disposed in the reaction shell, and tube plates at both ends. The inside is sectioned into two fluid spaces: a tube path and a shell path. The inlet port and the outlet port for the reaction gas are disposed at both ends of the reactor shell and each forms a tube path by communicating to the reaction tube through the tube plate. The inlet port for liquid and the outlet port for liquid are each disposed at a sidewall of the reactor shell to form a shell path. The reaction gas introduced to the reaction tube is a mixed gas of propylene and oxygen, and a catalyst is filled in the reaction tube. The reaction tube has a vertical multi-tubular structure and an outer diameter of the reaction tube is 40-50 mm, and the thickness is 0.5-5 mm.

Description

  The present invention relates to a multitubular fixed bed reactor for producing propylene oxide.

Fixed bed reactors are widely used in multiphase catalytic reaction processes, where solid particles are packed as a bed layer inside the reactor, and the fluid contacts the solid particles to cause a chemical reaction. Here, the fluid may be a gas and / or a liquid, and the solid particles may be a catalyst or a solid. The characteristics of the fixed bed reactor are that the reaction process is operated under high temperature and high pressure, the catalyst in the bed is hard to wear, the fluid flow can be regarded as an extrusion flow, and the residence time of the fluid in the bed is controllable. Can be mentioned.
A multitubular fixed bed reactor is one of the apparatuses commonly used in the chemical industry, and is commonly used for exothermic reactions. For this reason, it is necessary to quickly and effectively move the amount of heat generated in the reaction through the reaction medium or the supporting medium, to guarantee a temperature balance in the radial direction of the medium between the reaction tubes, and to avoid the occurrence of catalyst sintering. There is. Therefore, the heat transfer effect of the reactor is one of the main indicators for measuring the performance of the reactor. Therefore, in the prior art, the improvement related to the reactor is mainly concerned with the heat transfer property of the reactor, and the problem of the heat transfer effect of the reactor is solved by methods such as improvement of heat exchange medium and expansion of partition walls and passages. It was.

  Currently, in the large ethylene oxide / ethylene glycol industrialization equipment, the ethylene oxide reactor used for the highly active catalyst has a small diameter of the reaction tube. When a large multi-tube fixed bed reactor is used, the design pressure and design temperature are low. In addition, since the process medium is a gas mixture that is flammable and explosive and has a high toxicity hazard, there is an extremely high demand for the safety and reliability of the apparatus. For example, in an ethylene glycol apparatus with an annual production capacity of 100,000 tons, the number of reaction tubes of an ethylene oxide reactor is nearly 10,000, the diameter of the apparatus is 5160 mm, the height is 11400 mm, and the apparatus weight reaches 500 tons or more. This increases the design pressure of the reactor itself, increases the diameter, increases the required reactor wall thickness, increases the weight of the reactor, and increases the investment and transportation difficulty. Accordingly, there is a need to improve the design of ethylene oxide reactors on the premise of meeting the required productivity.

The ethylene oxide reactor is a multi-tubular fixed bed reactor, in which a catalyst is charged, and ethylene and oxygen pass through the reaction tube from top to bottom. The amount of heat generated by the reaction is discharged by the heat transfer water outside the reaction tube. Ethylene oxide generation by ethylene oxidation is a strong exothermic reaction under the action of silver catalyst, and carbon dioxide is by-produced as the combustion reaction is completed.
In the upper stage of the ethylene oxide reactor, part of the heat transfer water outside the reaction tube is cooled, and the amount of heat is transferred to the reaction gas in the reaction tube to reach the temperature required for the reaction. In the middle stage of the ethylene oxide reactor, the reaction gas transfers the released heat amount to the heat transfer water outside the reaction tube, and the heat transfer water outside the reaction tube boils to discharge the heat amount. In the lower stage of the ethylene oxide reactor, the reaction gas transfers heat to the heat transfer water outside the reaction tube, and the temperature of the heat transfer water outside the reaction tube gradually rises to the saturation temperature. The heat transfer process in the reaction tube is a convection heat transfer process from the top to the bottom, and the outside of the reaction tube is a cooling endothermic process, a boiling heat transfer process, and a convection heat transfer process from the top to the bottom.

  Patent Document 1 describes a multitubular fixed bed reactor for producing ethylene oxide.

CN27664474

Any conventional multi-tubular fixed bed reactor of ethylene oxide can be applied as a multi-tubular fixed bed reactor of propylene oxide, with some modifications. The main problem in the conventional multi-tubular fixed bed reactor of ethylene oxide is that the reaction tube diameter of the ethylene oxide reactor used for the high activity catalyst is usually 38.1 mm in the large ethylene oxide / ethylene glycol industrialization equipment, The required number of reaction tubes is usually 10,000 or more in order to satisfy the catalyst filling amount required for the reactivity to be achieved. A large number of reactor tubes inevitably increases the diameter of the reactor, further increases the reactor design pressure, increases the required reactor wall thickness, thus increasing the reactor weight, increasing the investment and The cost and difficulty of transportation will increase significantly.
Accordingly, an object of the present invention is to provide a propylene oxide multi-tubular fixed bed reactor in which the catalyst filling amount, the axial direction in the reaction tube, and the temperature distribution in the radial direction can all satisfy the required reactivity, and at the same time The overall size of the reactor is improved, the diameter is reduced, the wall thickness is reduced, the investment is saved, and a multi-tube fixed bed reactor that can be further adapted to the required productivity is provided.

In order to solve the above problems, the characteristics of the propylene oxide multitubular fixed bed reactor, that is, the temperature distribution in the axial and radial directions of the reactor, The following inventions were studied in consideration of important data such as spot temperature and position, heat flow rate, raw material composition, propylene conversion rate and propylene oxide selectivity, boiling water vaporization fraction distribution and drum height. I found.
[1] A reactor shell, a reaction gas inlet, a reaction gas outlet, a liquid inlet, a liquid outlet, a reaction tube disposed inside the reactor shell, and tube plates at both ends, the inside being a tube The reaction gas inlet and the reaction gas outlet are arranged at both ends of the reactor shell, and communicate with the reaction tube via the tube plate to form a pipe line, A liquid inlet and a liquid outlet are respectively provided on the side wall of the reactor shell to form a shell path, and the reaction gas entering the reaction tube is a mixed gas of propylene and oxygen, and the reaction tube is filled with a catalyst. A multi-tubular fixed bed reactor for the production of propylene oxide,
The multi-tube fixed bed reactor characterized in that the reaction tube has a vertical multi-tube structure, the reaction tube has an outer diameter of 40 to 50 mm, and a wall thickness of 0.5 to 5 mm.

[2] The multitubular fixed bed reactor according to [1], wherein the reaction tube has an outer diameter of 42 to 48 mm and a wall thickness of 0.5 to 5 mm.
[3] The multi-tube fixed bed reactor according to [1], wherein the outer diameter of the reaction tube is 45 to 46 mm and the wall thickness is 0.5 to 5 mm.
[4] The reaction gas inlet is arranged at the top of the reactor shell, the reaction gas outlet is arranged at the bottom of the reactor shell, and the liquid inlet and the liquid outlet are sequentially arranged at the lower part and the upper part of the side wall of the reactor shell. The multitubular fixed bed reactor according to [1], wherein each is arranged and the liquid outlet is a boiling water outlet.
[5] The multi-tube fixed bed reactor according to [1], wherein a catalyst is provided inside the reaction tube, and both ends of each reaction tube are filled with an inactive filler.
[6] The multitubular fixed bed reactor according to any one of [1] to [5], wherein the catalyst is a catalyst containing (a) copper oxide and (b) ruthenium oxide.

  According to the multi-tubular fixed bed reactor of propylene oxide of the present invention, the catalyst filling amount, the axial direction in the tube and the temperature distribution in the radial direction can all satisfy the required reactivity, and at the same time the overall size of the reactor is Improved, shorter diameter and thinner wall thickness saves investment and is more adaptable to required productivity.

1 is a schematic structural diagram of a propylene oxide reactor according to the present invention.

Examples of the method for catalytic vapor phase oxidation of propylene oxide to which the present invention can be applied include a production method in which propylene and oxygen are reacted in the presence of a metal catalyst containing a metal oxide or the like. For the production method of reacting propylene and oxygen in the presence of such a metal catalyst, for example, WO2011 / 075458, WO2011 / 0754559, WO2012 / 005822, WO2012 / 005823, WO2012 / 005824, WO2012 / 005825, WO2012 / 005831, WO2012 / 005832, WO2012 / 005835, WO2012 / 005837, WO2012 / 009054, WO2012 / 009059, WO2012 / 009058, WO2012 / 009053, WO2012 / 009057, WO2012 / 009055, WO2012 / 009055, WO2012 / 009055 and the like. As the catalyst used in the production method, the following (a), (b), (c), (d), (e), (f), (g), (h), (i), (j), ( and a catalyst containing at least two selected from the group consisting of k), (l), (m), (n), (o), (p) and (q).
(A) copper oxide (b) ruthenium oxide (c) manganese oxide (d) nickel oxide (e) osmium oxide (f) germanium oxide (g) chromium oxide (h) thallium oxide (i ) Tin oxide (j) Bismuth oxide (k) Antimony oxide (l) Rhenium oxide (m) Cobalt oxide (n) Osmium oxide (o) Lanthanoid oxide (p) Tungsten oxide (q) Alkali Metal component or alkaline earth metal component, preferably a catalyst containing (a) copper oxide and (b) ruthenium oxide, more preferably (a) copper oxide, (b) ruthenium oxide and (j) A catalyst containing an alkali metal component or an alkaline earth metal component.

The multi-pipe fixed bed reactor for producing propylene oxide of the present invention comprises a reactor shell 1, a reaction gas inlet 2, a reaction gas outlet 3, a liquid inlet 4, a liquid outlet 5, and the reactor shell 1. It includes a reaction tube 6 disposed inside and tube plates 7 at both ends, and the inside of the reactor is divided into two fluid spaces, a pipe line and a shell path, and the reaction gas inlet 2 and the reaction gas outlet 3 are Disposed at both ends of the reactor shell 1 and communicated with the reaction tube 6 through the tube plate 7 to form a pipe line. The liquid inlet 4 and the liquid outlet 5 are respectively provided on the side walls of the reactor shell 1. A reaction gas that forms a shell path and enters the reaction tube 6 is a mixed gas of propylene and oxygen, and the reaction tube 6 is filled with a catalyst 8.
In the multi-tube fixed bed reactor, the reaction tube 6 has a vertical multi-tube structure, the reaction tube 6 has a thickness of 0.5 to 5 mm, and an outer diameter of 40 to 50 mm. It is 42-48 mm, More preferably, it is 45-46 mm.

In a specific use, the reaction gas inlet 2 is located at the top of the reactor shell 1 and the reaction gas outlet 3 is located at the bottom of the reactor shell 1. The liquid inlet 4 and the liquid outlet 5 are sequentially arranged at the lower part and the upper part of the side wall of the reactor shell 1, respectively, and the liquid outlet 5 is a boiling water outlet. A catalyst 8 is provided inside the reaction tube 6, and an inert filler 9 is filled at each end of each reaction tube 6. Examples of the inert filler include silica, alumina, aluminosilicate, silicoaluminate, clay mineral, magneside, dolomite, magnesia, zirconia, calcium oxide, silicon carbide, and alumina-silica molded body. Those which do not substantially change the reaction raw materials or products are preferred. The shape may be spherical, hemispherical, spheroid, cylindrical, ring-shaped, pellet-shaped, or granular-shaped, and preferably has a small pressure loss. Moreover, the size is about 1-20 mm normally.
The material of the multi-tubular fixed bed reactor or shell is not particularly limited, and carbon steel, stainless steel, alloy, etc. can be used.

  Speaking of the multi-tube fixed bed reactor for producing ethylene oxide in an ethylene glycol apparatus with an annual production of 100,000 tons, the outer diameter of the reaction tube was 38.1 mm, and the diameter of the reactor was 5160 mm. For the same production scale, in the reaction tube diameter of the multitubular fixed bed reactor for producing propylene oxide of the present invention, the above 38.1 mm is expanded to 40 to 50 mm. From the research and test of the present invention, the catalyst filling amount, the axial direction in the pipe, and the temperature distribution in the radial direction of the multitubular fixed bed reactor of the present invention can satisfy the required reactivity. For example, when the outer diameter of the reaction tube is 45 to 46 mm, the diameter of the multitubular fixed bed reactor of the present invention can be suppressed to 5000 mm or less. In this way, the overall size of the multitubular fixed bed reactor is further improved, the reactor diameter is reduced, the length ratio is more rational, and the wall thickness is reduced at the same time. As a result, the overall weight of the device is reduced, investment is saved and it can be further adapted to the required productivity.

Hereinafter, in order to describe the present invention in more detail, specific embodiments will be described based on the drawings. However, the present invention does not limit the scope of the present invention only by this embodiment.
As shown in FIG. 1, in the multitubular fixed bed reactor of the present invention, the reaction gas entering the reaction tube 6 is a mixed gas of propylene and oxygen, and the reaction tube 6 is filled with a catalyst 8. The reactor includes a reactor shell 1, a reaction gas inlet 2, a reaction gas outlet 3, a liquid inlet 4, a liquid outlet 5, a reaction tube 6 disposed inside the reactor shell 1, both ends Tube sheet 7. The inside of the reactor is divided into two fluid spaces, a pipe line and a shell path. The reaction gas inlet 2 and the reaction gas outlet 3 are arranged at both ends of the reactor shell 1 and communicate with the reaction tube 6 through the tube plate 7 to form a pipe line. The liquid inlet 4 and the liquid outlet 5 are respectively provided on the side wall of the reactor shell 1 to form a shell path.
The reaction tube 6 has a vertical multi-tube structure, the reaction tube 6 has a thickness of 0.5 to 5 mm, and an outer diameter of 40 to 50 mm, preferably 42 to 48 mm, more preferably 45 to 46 mm. .

  The reaction gas inlet 2 is provided at the top of the reactor shell 1, and the reaction gas outlet 3 is provided at the bottom of the reactor shell 1. The liquid inlet 4 and the liquid outlet 5 are sequentially provided at the lower part and the upper part of the side wall of the reactor shell 1, respectively, and the liquid outlet 5 is a boiling water outlet. A catalyst 8 is installed inside the reaction tube 6 and both ends of each reaction tube 6 are filled with an inert filler 9.

  According to the multi-tubular fixed bed reactor of propylene oxide of the present invention, the catalyst filling amount, the axial direction in the tube and the temperature distribution in the radial direction can all satisfy the required reactivity, and at the same time the overall size of the reactor is Improved, shorter diameter and thinner wall thickness saves investment and is more adaptable to the required productivity.

1 reactor shell 2 reactive gas inlet 3 reactive gas outlet 4 liquid inlet 5 liquid outlet 6 reaction tube 7 tube plate 8 catalyst 9 deactivation filler

Claims (6)

A reactor shell, a reaction gas inlet, a reaction gas outlet, a liquid inlet, a liquid outlet, a reaction tube disposed inside the reactor shell, and tube plates at both ends, the inside being a pipe line and a shell The reaction gas inlet and the reaction gas outlet are arranged at both ends of the reactor shell and communicate with the reaction tube through a tube plate to form a pipe line, Each of the liquid outlets is provided on a side wall of the reactor shell to form a shell path, the reaction gas entering the reaction tube is a mixed gas of propylene and oxygen, and the reaction tube is filled with propylene oxide. A multi-tube fixed bed reactor for manufacturing,
The multi-tube fixed bed reactor characterized in that the reaction tube has a vertical multi-tube structure, the reaction tube has an outer diameter of 40 to 50 mm, and a wall thickness of 0.5 to 5 mm.   The multi-tube fixed bed reactor according to claim 1, wherein the outer diameter of the reaction tube is 42 to 48 mm and the wall thickness is 0.5 to 5 mm.   The multi-tube fixed bed reactor according to claim 1, wherein the outer diameter of the reaction tube is 45 to 46 mm and the wall thickness is 0.5 to 5 mm.   The reaction gas inlet is disposed at the top of the reactor shell, the reaction gas outlet is disposed at the bottom of the reactor shell, and the liquid inlet and the liquid outlet are sequentially disposed at the lower part and the upper part of the side wall of the reactor shell, respectively. The multitubular fixed bed reactor according to claim 1, wherein the liquid outlet is a boiling water outlet.   The multi-tube fixed bed reactor according to claim 1, wherein a catalyst is provided inside the reaction tube, and both ends of each reaction tube are filled with an inactive filler.   The multitubular fixed bed reactor according to any one of claims 1 to 5, wherein the catalyst is a catalyst containing (a) copper oxide and (b) ruthenium oxide.

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