JPS59225725A - Catalytic reaction method - Google Patents

Abstract

PURPOSE:To enhance the activity of a catalyst by reducing the particle size thereof while supporting a small particle size moving layer by a large particle size moving layer, by dividing a moving layer type reactor in parallel while arranging catalyst particles so as to successively transfer the particle size thereof from a small particle size to a large particle size. CONSTITUTION:The container 7 arranged in a reactor is formed of a metal net, a perforated iron plate or a multifoliate plate and catalyst partitioning plates 7a, 7b each comprising a metal net or a perforated iron plate are further parallelly arranged in a vertical direction in the container 7 so as to divide the interior thereof. The container 7 is packed with catalyst particles comprising an ore or the like to form a plurality of catalyst particle moving layers 81-83. The gaps of the partitioning plates 7a, 7b are made larger than the particle size of the catalyst so as to generate no clogging. In addition, the particle size range of the catalyst particles in the moving layer 81 in the inflow side of exhaust gas 1 is min. and the particle size ranges of catalyst particles in the moving layers 82, 83 in the after-stream side successively become large.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides deodorization of exhaust gas (including removal of HC and CO),
This invention relates to a catalytic reaction method for denitrification, etc.

As this type of catalytic reaction method, one using an ore having catalytic activity is known, and an example thereof is shown in FIG. In this method, exhaust gas 1 is introduced into a heat exchanger 3 by a blower 2, and then preheated in a heating furnace 4 to -1-IA' 200 to 450°C. Then, in the case of denitration, ammonia gas 5 is added and mixed, and this exhaust gas is introduced into a moving bed reactor 6. This reactor 6 has a container 7 inside.
are placed. The side surface of the container-a7 is made of wire mesh, perforated iron plate, multi-leaf plate, etc., and the inside contains catalyst particles (such as ore).
A moving layer 8 having a particle size of 2 to 30 mmφ is filled and formed.

A hopper 9 is provided in the upper part of this container 7, and holds the catalyst particle transfer layer 8 airtightly. This configuration glue actor
The exhaust gas introduced into the reactor 6 is deodorized or denitrated by contacting the catalyst particles constituting the moving bed 8 of the reactor 6, passes through the heat exchanger 3, and is exhausted from the chimney 10.

On the other hand, the catalyst particles constituting the moving bed 8 descend one by one due to gravity and are discharged onto the screw conveyor II from the lower end. The conveyor xr is supplied with catalyst particles from the supply hopper 12, and these catalyst particles are sent to the sieve I3. The sieve 13 is provided with a fine screen, and the 1-2-catalyst in the upper part of the sieve is charged from the hopper 9 by an elevator 14 such as a packet elevator and reused. Further, the catalyst in the lower part of the sieve is discharged as dust 15 and is effectively used as a raw material for blast furnace or sintering.

However, in this method, it is desirable to reduce the particle size of the catalyst particles to increase the surface area ratio ((to)2/ωa) and improve the catalytic activity. There is a problem with this.

That is, the ore catalyst particles are filled in a container 2 having a multi-leaf plate (or perforated plate, wire mesh, etc.), but in order to make this container 2 compact, the space velocity (gas It is necessary to carefully adjust the passing area (X-ray velocity ty/catalyst volume = gas passing discharge/catalyst body volume). However, if the linear velocity is designed to be large in order to increase the space velocity, the small catalyst particles will cause blow-through and scattering. In order to prevent this, if the gaps in the container 2 are made narrower, clogging will occur, resulting in increased pressure loss of the processing gas, making it impossible to operate the gaps. Moreover, the strength of the container 2 is weakened, making it vulnerable to wear and corrosion.

Therefore, in the conventional method, the catalyst particle size range exceeds a certain size (
For example, it was limited to 2 tomoφ or more).

The present invention was made to solve this problem, and its purpose is to provide a catalytic reaction method that can prevent clogging of ore catalysts, improve catalytic activity, and make equipment more compact. It is something that you are trying to gain.

In the catalytic reaction method, the catalyst particles are divided into a plurality of particle size groups, and these particle size groups are arranged in parallel from the small particle size group to the large particle size group to form a plurality of moving layers. By passing the exhaust gas from the rear group moving layer to the large particle rear group moving layer, the small particle rear group moving layer is supported by the large particle rear group moving layer, improving the activity and utilization rate by reducing the particle size of the catalyst. It is characterized by:

The present invention will be described below with reference to illustrative embodiments.

FIG. 2 is an explanatory diagram of the catalytic reaction apparatus used in the method of the present invention,
Figure 3 is an enlarged view of the main parts. This catalytic reaction apparatus is equipped with a blower 2, a heat exchanger 3, a heating furnace 4, a conveyor 11, etc., but the configuration is the same as the conventional one shown in Fig. 1, so the same numbers are given. Therefore, the explanation will be omitted. On the other hand, the container 7 placed inside the reactor 6 is carved out of a wire mesh, a perforated iron plate, or a multi-leaf board.
7b is divided vertically in parallel. The inside of the container 7 divided by partition plates 7a r 7b is filled with catalyst particles such as ore, and a plurality of catalyst particle movement layers 8. ~
83 is formed. In this case, the partitions υ plates 7a and 7b are
The gap is made larger than the diameter of the tentacles to prevent clogging. Further, the particle size range of the catalyst particles in the moving bed 8I on the inflow side of the exhaust gas I is the smallest, and the moving bed 82++ on the downstream side of the exhaust gas 1! ? The particle size range of the catalyst particles in No. 3 is gradually increased.

Here, the particle size of the catalyst particles filled in the moving bed 81 rat +88 is preferably set to have an upper limit of 5 wφ and a lower limit of 0.01 Uφ. The reason why the particle size is preferably 5 mtnφ or less is that, for example, a crushed catalyst such as ore with a particle size of 0.01 mttcφ or less is mixed with a binder such as cement and moisture to form a pellet-like catalyst with a particle size of 2 to 5 mmφ. Granulate with a granulator,
This is because by filling the latter stage of the moving bed, the utilization rate of ore, etc. can be improved. Also, the particle size is 0.01
The reason why mytφ or more is preferable is that if the particle size is larger than this, dust etc. and the catalyst itself can be easily separated. In addition, the particle size range of the catalyst particles packed in each moving bed is
It is necessary to set it within a range that does not pass through the catalyst particles packed in the latter moving bed. Further, the number of moving layers is not limited to three stages, but to give an example of the particle size range when formed in three stages, the first stage moving layer has a particle diameter of 0.4 to 0.8 xiφ, and the second stage has a particle diameter of 0.4 to 0.8 xiφ. .8~1.6 rnrnφ, 3rd stage is 1.6~3.
It is 2 mmφ.

Further, on the upper part of the container 7, each moving layer 8. Hoppers 9 to 93 are provided corresponding to N, moving layers 8 and 8.
3 is kept airtight. A conveyor 11 such as a set of screws is provided at the lower outlet I6 of this container 7, and a plurality of sieves 13 are provided correspondingly to the conveyor II.
1-I3. (or classifier) is provided in the vertical direction.

Each part 13. ~13. Each separates catalyst particles into particle size ranges, and the outlet thereof is connected to the upper part of the hopper 91 to 9 degrees by an elevator 14 to 143, such as a packet elevator 1 and a pneumatic elevator. In addition, hopper 9. A rotary feeder or the like may be provided at ~9° or the lower outlet 16 to further improve mechanical airtightness.

According to the method of the present invention, the wandering gas 1 is brought into contact with catalyst particles in the following manner to cause a predetermined catalytic reaction to occur.

After the exhaust gas I is introduced into the heat exchanger 3 by the blower 2, it is preheated to 200 to 450°C in the heating furnace 4. Next, in the case of the denitration method, ammonia gas 5 is added to and mixed with the exhaust gas 1, and in the case of the deodorization method, it is introduced into the reactor 6 without adding ammonia gas. The exhaust gas I introduced into the reactor 6 first comes into contact with the small-sized catalyst particles in the small rear group moving layer 81, then contacts the catalyst particles in the moving layer 8 on the rear side of this, and then further on the rear side. Some mobile layer8. The gas contacts the catalyst particles inside and undergoes a predetermined catalytic reaction, becomes harmless and odorless, and becomes clean gas 17, which is introduced into the heat exchanger 3.

Here, the heat of the clean gas I7 is used to warm the untreated exhaust gas 1, and the pressure or flow rate inside the reactor 6 is adjusted, after which it is discharged from the chimney 10.

On the other hand, the catalyst particles in the moving beds 81 to 83 descend one by one due to gravity and are discharged onto the conveyor 11 from the outlet I6. The catalyst particles on the conveyor 11 are passed through the sieve 13. ~133 where it is divided into multiple particle size ranges. Next, these are charged from the hoppers 91 to 93 through the elevators 14 to 143 together with the catalyst particles replenished from the replenishment hopper 12, and the moving beds 81 to 8. Inner touch/s: Reuse as particles.

Sieve 13. ~13. The separated catalyst in the lower surface portion is discharged as dust 15 and effectively used as part of the charging raw material for a sintering furnace or a pellet furnace.

According to this method, the front moving bed made of small-sized catalyst particles is stably supported by the rear moving bed made of large-sized catalyst particles, so there is no scattering or blow-through of the small-sized catalyst, and the catalyst becomes active. can be improved.

Next, the present invention will be explained in detail.

Example 1 Removal experiment of nitrogen oxides in exhaust gas Flue gas denitrification was carried out under the following conditions using the apparatus shown in Figure 2 (method of the present invention) and, for comparison, using the equipment fM shown in Figure 1 (conventional method). An experiment was conducted and the results are shown in Table 1.

9- Sintering furnace exhaust gas amount 25.2Nm'/H N in exhaust gas
Ox amount 200-220ppm SO2 amount in exhaust gas
2 ppm Dust amount in exhaust gas 50■/Nm”NH, addition amount 220 ppm Reactor population grade 3
00°C area (Table 1 ■ Example 2 Experiment for removing hydrocarbons from paint exhaust gas An experiment for removing HC was conducted using the apparatus shown in the figure under the following conditions.

The results are illustrated in Table 2.

Steel plate painting exhaust gas 36.0 Nm3/H18,
rpA, 1 butanol, ethanol, ethyl cellosolve, etc.) Amount of dust in exhaust gas 200 rn9/N m8 reactor temperature 300'C Table 2 Based on these results, according to this example, catalyst activity, i.e., denitrification When the deodorizing efficiency is kept constant, the catalyst space velocity can be improved to about twice that of the conventional method. In addition, when ores are crushed and used, even small particle sizes can be used, and the amount of medicine used can be more than twice as much as with conventional methods.In particular, if pellets are granulated, the utilization rate can be increased to 100%. be able to.

Further, the moving bed in the front stage of the reactor is a moving bed with fine particle size and has a dust collection function, and the dust is sieved in a subsequent process. Therefore, there is no problem even if exhaust gas containing a lot of dust is passed through untreated, and it can be effectively treated.

Furthermore, some of the catalyst particles in the moving bed are crushed and powdered during the movement, but by controlling the moving speed (amount), the surface of the catalyst particles such as ore is worn away and a new virgin surface is created.
As a result, catalyst activity can be maintained at a high level.

As described above, according to the present invention, a small particle size catalyst is stably held by a large particle size catalyst, so a catalyst with a small particle size is used compared to the conventional method, increasing catalytic activity and preventing clogging. This has the remarkable effect of reducing the size of the equipment, and in the case of ore catalysts, increasing the utilization rate.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional catalytic reaction method, FIG. 2 is an explanatory diagram of a catalytic reaction method showing an embodiment of the present invention, and FIG. 3 is an enlarged view of the same essential parts. DESCRIPTION OF SYMBOLS 1... Exhaust gas, 2... Blower 13... Heat exchanger, 4... Heating furnace, 5... Ammonia gas, 6...
Reactor, 7... Container, 7a, 7b... Partition root, 8° 8I~8. ...Catalyst particle moving bed, 9,9I~9
゜...Hopper, 10...Chimney, II...Conveyor, I2...Replenishment hopper 513p13□~133
...Sieve, 14,14. ~14. ...Elevator-1
15...Dust, I6...Lower outlet, 17...Clean gas. Applicant's agent Patent attorney Takehiko Suzue No. 1 Figure 3 JP-A-59-225725 (5) Figure 3

Claims (1)

[Claims] In a catalytic reaction method in which exhaust gas is passed through and brought into contact with a moving bed of catalyst particles that descend by gravity in a moving bed reactor, the catalyst particles are divided into multiple particle size groups, and these particle size groups are sequentially divided from small particle size groups to large particle size groups. A catalytic reaction method characterized in that a plurality of moving layers are formed in parallel arrays so as to form a group, and exhaust gas is passed from the small particle rear group moving layer to the large particle rear group moving layer.