JPS61146339A - Method and apparatus for rotating fluidized contact reaction - Google Patents

Abstract

PURPOSE:To obtain the high degree of reaction by rotating the gaseous raw material for reaction from the bottom of a vertical reaction pipe to the top and fluidizing the catalyst particles in the gas stream. CONSTITUTION:In the fluidized contact reaction of the petroleum purification and the chemical industry or the like, a cone pipe 21 wherein the diameter is gradually enlarged is connected to the lower part of a reaction pipe 1 and furthermore a cylindrical pipe 22 having the same diameter as the large diameter of the cone pipe 21 is connected to the cone pipe 21. An introduction pipe 24 of the gaseous raw material for reaction is fitted in the angle slanted to a base plate 23 toward the central line of the cylindrical pipe 22 and also a collection chamber 11 of catalyst particles having a diameter larger than the reaction pipe 1 is provided to the upper part of the reaction pipe 1 and a conduit 12 for circulating the catalyst particles from the lower part of the collection chamber 11 to the lower part of the reaction pipe 1 is provided. The gaseous raw material for reaction is rotated from the lower part of the reaction pipe 1 to the upper part and the catalyst particles are fluidized in the gas stream. By such method, high degree of reaction is obtained in the fluidized contact reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a fluid catalytic reaction method and apparatus useful in the fields of petroleum refining, chemical industry, and public pollution control.

The method of introducing a reaction raw material gas into a reactor filled with a finely divided catalyst to form a fluidized catalyst bed and carrying out a catalytic reaction allows for easy exchange of reaction heat and a uniform temperature distribution. For example, in the FCC process in petroleum refining, hydrocarbons are lightened and degraded in the first fluidized catalyst bed. A method is used in which the catalyst is systematically extracted, guided to a second fluidized catalyst bed, regenerated with air, and continuously replenished to the first fluidized catalyst bed.

In this case, the fine particulate catalyst is in a highly disturbed state, so when looking at individual catalyst particles, the residence time in the reaction tower or regeneration tower will differ greatly from the average value. Therefore, some parts of the catalyst remain in the reaction tower and circulate even though they have already lost their activity, and some parts are extracted from the reaction tower and circulated in the regeneration tower even though they still have sufficient activity. A similar phenomenon occurs in the regeneration tower. This leads to a decrease in the space utilization efficiency of the reaction tower or regeneration tower and an increase in energy consumption.

Unlike the conventional fluidized bed described above, the present invention provides a catalytic reaction method and apparatus in which catalyst particles participate in the reaction while rotating in a fluidized state, and solves the problems in the conventional fluidized catalytic reaction. In addition to solving problems, it is also expected to be applied to chemical reactions that have not previously been carried out using fluidized catalysts.

The present inventors have previously discovered that chemical reactions are promoted in the state of spiral airflow in pipes, and have filed a patent application (Japanese Patent Application No. 16124/1982). This is an extension of catalytic reactions using catalysts.

That is, the present invention provides a swirling flow in which a swirling flow of reaction raw material gas is formed in a vertical reaction tube from the bottom to the top, and catalyst particles are made to flow in the gas flow to promote a catalytic reaction of the gas. The present invention relates to a catalytic reaction method and an apparatus for carrying out the method.

FIGS. 1 and 2 show the basic concept of an apparatus for carrying out the method of the invention, in which a swirling flow of gas is formed in a vertical reaction tube 1 proceeding from the bottom to the top.

In order to form a swirling flow in the reaction tube, the spiral airflow generating device described in Japanese Patent Application No. 164192/1987, etc., which was invented by the inventors of the present application, is used. As an example, a cone tube 21 connected to the lower part of the reaction tube 1 and having a diameter gradually expanding in the opposite direction to the reaction tube;
A cylindrical pipe 22 of the same diameter connected to the large diameter part of the cone pipe,
It consists of a bottom plate 23 that closes the other end of the cylindrical tube, and a reaction raw material gas feed pipe 24 that is attached to the side of the cylindrical tube at a position away from the bottom plate, facing the center line of the cylindrical tube and at an angle inclined toward the bottom plate. ing.

The spiral airflow generating device and the vertical reaction tube may be connected through a bent tube 3 as shown in FIG. 1, or directly connected to the lower part of the vertical reaction tube as shown in FIG.

Furthermore, a catalyst particle collection chamber 11 having a diameter larger than the diameter of the reaction tube is provided above the reaction tube 1. A conduit 12 for extracting catalyst particles from the lower part of the catalyst particle collection chamber and circulating them to the reaction tube inlet or catalyst regeneration tube inlet as necessary.
After the reaction, the gas is discharged from the outlet pipe 13.

To explain the configuration of the spiral airflow generation device 2 from a functional perspective, first, the reaction raw material gas inlet pipe 24 is attached to the side of the cylindrical tube at a position away from the bottom plate 23, so gas accumulates near the bottom plate of the cylindrical tube. I can do it.

The gas fed from the reaction raw material gas feed pipe installed at a feed angle tilted toward the bottom plate hits the above gas pool diagonally and turns once and heads toward the cone tube, but at this time, the gas pool is It acts like a cushion, eliminating minute pulsations in the gas being fed and disturbances that occur during feeding, and pushing the gas back toward the cone tube in an even pressure state with no pressure drop. The reason for installing the gas inlet tube toward the center line of the cylindrical tube is to avoid generating a swirl vector here.

Thus, in the cylindrical portion beyond the mounting position of the gas feed pipe 24, the gas is in an uncompressed state with equal pressure and is essentially given only a vector in the long sleeve direction, and moves toward the cone pipe.

The cone tube 21 has a shape in which the diameter of the cylindrical tube gradually decreases to become equal to the diameter of the reaction tube, so the gas flowing through the cylindrical body gradually increases in speed and reacts at high speed. It is now fed into the bottom of the tube.

If the gas is fed under such conditions, it is expected that the gas will continue to flow to the outlet while maintaining the state of piston flow, but if the average speed of the airflow exceeds 20 m/s, a stable spiral airflow will occur inside the reaction tube. That is, with respect to the cross section of the reaction tube, a stable airflow is generated that travels in the long sleeve direction while forming a swirling flow.

Of course, since the spiral airflow itself is a gas, it cannot be observed directly with the naked eye, but the existence of the spiral airflow can be confirmed by the experiment described below.

Experiment 1 The structure was as shown in Fig. 1, and the air flow introduced from the spiral airflow generating device 2 was made to flow from the bottom to the top of the vertical tube 1 made of a transparent plastic tube with an inner diameter of 1.5 inches. FIG. 4 shows a partially enlarged view of the vertical pipe 1.

When a synthetic resin pellet (cylindrical shape with a diameter of 5 mm and a length of 5 mm) is fed into this rising airflow, if the airflow velocity is sufficiently fast, the pellet will instantly pass through this vertical tube from the bottom to the top. , by adjusting the airflow velocity so that the downward vector due to gravity acting on the pellet and the upward vector due to the airflow are balanced, the pellet will remain at a fixed position 1 in the vertical tube, for example at the position A-A' in Figure 4. The movement can be observed with the naked eye. Figure 5 is A- of Figure 4.
Although it is a cross-sectional view taken along the A' line, it can be observed that the pellet 4 is making a swirling motion as shown by the arrow. A-
When part A' is held down by hand and squeezed, the flow velocity in this part increases, so the pellet flies upward, moves to the equilibrium point B-B' slightly above, and continues the swirling movement in this cross section. In this case, the pellet 4 is not in direct contact with the tube inner wall 14. That is, in a portion close to the inner wall 14 of the tube, an annular air layer 5 is formed that is compressed by centrifugal force based on the swirling flow (the thickness of the annular air layer is exaggerated in the figure, but it is actually less than 1 mm). , the thickness is on the order of microns), therefore, at the boundary with the annular air layer, the pellets are rotated by the rotating vector of the spiral airflow in a fixed plane under the balance between the upward vector of the spiral airflow and the downward vector of gravity. There is.

If the flow velocity of the airflow is increased from this equilibrium state, the pellet itself will also rise while drawing a spiral flow. This swirling phenomenon is also observed when there are a large number of pellets.

Therefore, if catalyst particles are used instead of pellets, the catalyst particles will be in a swirling flow state in which they swirl at a constant level or in a swirling flow state in which they slowly rise depending on the gas velocity.

In the present invention, the reaction is carried out using the catalyst in this swirling flow state, and the gaseous composition involved in the reaction is fed from the spiral air flow generating bag W2 to introduce the reaction raw materials into the reaction tube 1. A spiral gas flow is generated, and the catalyst particles are brought into contact with each other in a swirling flow state.

The gas fed into the reaction system is not necessarily limited to the reaction raw material gas, but may also include an inert gas for the purpose of improving the swirling flow state of the catalyst particles or diluting the reaction heat. good.

Depending on the type of reaction, the properties of the catalyst, etc., the reaction can be carried out in a fluid state in which the catalyst layer as a whole swirls at a constant level, or it can be carried out in a fluid state in which the catalyst layer as a whole swirls at a constant level, or it can be carried out in a fluid state in which the catalyst layer as a whole swirls at a constant level. 11 is collected in the conduit 12
It is also possible to carry out the reaction in a fluid state in which the mixture is circulated through the inlet of the reaction tube.

Since the catalyst particle collection chamber has a larger diameter than the reaction tube,
The gas velocity now decreases, and the catalyst flow particles that were in balance with the downward gravitational vector in the reaction tube section either settle back into the reaction tube or are deposited along the walls of the collection chamber, leaving the conduit 12.
It is circulated to the inlet of the reaction tube.

When using and regenerating the catalyst repeatedly, for example when regenerating the catalyst by air oxidation, a regeneration tube 1' similar to the reaction tube is installed as shown in Fig. 3, and the catalyst overflowing from the reaction tube 1 is The catalyst is introduced into the lower part of the regeneration pipe 1' through the particle collection chamber 11 and the conduit 12, and oxidized and regenerated in a swirling flow state by introducing air from the spiral airflow generator 2', and overflows from the regeneration pipe 1'. is fed into the lower part of the reaction tube 1 via the catalyst particle collection chamber 11' and the conduit 12'.

In the swirling fluidized catalyst bed formed in this way,
A phenomenon different from that of conventional fluidized catalyst beds is observed.

As is clear from Experiment 1, a stable spiral airflow is formed inside the reaction tube. If you look at the 11+3g whirlpool flow projected onto the cross section of the pipe, it is a rotational motion, and the centrifugal force accompanying the rotation throws the gas particles inside to the outside, forming a compressed thin layer of gas along the inner wall of the pipe. , the gas density is low inside.

In addition, the average velocity of the airflow that generates the spiral airflow is higher than the airflow velocity that forms the conventional fluidized catalyst bed, and a part of the kinetic energy is converted into the energy of the swirling motion, so the reaction gas and catalyst The kinetic energy imparted to the particles is much greater than in a conventional fluidized bed.

As a result, a higher reaction rate can be obtained than in conventional fluidized catalytic reactions. It is also expected to be applied to various reactions that have not been attempted with conventional fluidized catalytic reactions.

The shape of the reaction tube is not limited to the straight tube shown in FIGS. 1 and 2. As shown in FIG. It is also possible to perform a stepwise reaction by constructing a swirling fluidized bed of different catalysts.

In addition, considering the increase and decrease in the amount of gas as the reaction progresses, the seventh
It may be tapered or reversely tapered as shown in FIG. 8 and FIG.

Also, the swirling flow generating device is not limited to the one shown in the figure; for example, the device described in Japanese Patent Application No. 59-239528, or any other device that generates swirling motion of solid particles as shown in Experiment 1, may be used. All can be used.

Example 1 As shown in Fig. 2, zeolite l-X-
Filled with 5 g of Na catalyst particles, fed N2 gas to swirl and flow the catalyst particles, and diisobutylene at 1.25 g/g.
A catalytic cracking reaction was carried out at 300° C. by feeding the gas at a rate of “Cat -hr-”.The gasification rate was 38.6%.

Comparative Example 1 Diameter 1.5 cm, length 1 m without spiral airflow generation device
The test was conducted in the same manner as in Example 1, except that a normal fluidized bed was formed using N2 gas using a reaction tube.

The gasification rate was 24.1%.Example 2 A test was conducted in the same manner as in Example 1 except that zeolite (X-Ca) was used as the catalyst. Gasification rate is 55.2%
Met.

Comparative Example 2 Example 3 except that zeolite)X-Ca was used as a catalyst
The test was conducted in a similar manner. The gasification rate was 35.9%.

衾"LD"Ll As is clear from the Examples and Comparative Examples, by involving the catalyst particles in the reaction in a swirling fluid state, a higher reaction rate can be obtained than in the conventional fluid catalytic reaction.

[Brief explanation of the drawing]

Figures 1 and 2 show the basic concept of an apparatus for carrying out the method of the present invention. Figure 1 shows a type in which a reaction tube and a spiral airflow generator are separated, and Figure 2 shows a type in which they are separated. Indicates something that is directly connected and integrated. Figure 3 shows an apparatus in which two units of the type shown in Figure 2 are arranged in parallel to continuously carry out catalytic reactions and catalyst regeneration. Figures 4 and 5 show a spiral airflow generated in the reaction tube. FIG. 3 is an explanatory diagram of an experiment showing that the introduced solid particles perform a swirling motion. FIG. 6, FIG. 7, and FIG. 8 are examples of shapes of reaction tubes.

Claims (1)

[Claims] 1. A method comprising forming a swirling flow of a reaction raw material gas proceeding from the bottom to the top in a vertical reaction tube, and flowing catalyst particles into the gas flow to promote a catalytic reaction of the gas. Swirling flow catalytic reaction method. 2 Vertical reaction tubes, cone tubes connected to the bottom of the reaction tube and gradually increasing in diameter in the opposite direction to the reaction tube, cylindrical tubes with the same diameter connected to the large diameter part of the cone tube, cylindrical tubes, etc. A bottom plate that closes the end, a reaction raw material gas inlet pipe installed at a position away from the bottom plate on the side of the cylindrical tube at an angle toward the center line of the cylindrical tube and tilted toward the bottom plate, and a tube provided at the top of the reaction tube. A swirling flow catalytic reaction device comprising a catalyst particle collection chamber having a diameter larger than that of a reaction tube.