JPS637834A - Cooling method for extracting catalyst in reaction vessel - Google Patents

Abstract

PURPOSE:To cool catalysts efficiently with a simple operation by circulating and introducing a cooled non-active gas into a reaction vessel when extracting catalysts in a reaction vessel and cooling the catalysts in the reaction vessel. CONSTITUTION:To cool down catalysts in a reaction vessel 1 prior to extracting, nitrogen gas 10 as a non-active gas in so flowed into a duct 6 through a flow regulating valve 9 as to set the pressure in the circulation system of a device higher by about 0.1-0.3kg/cm<2> G. Next, after being exhausted out of a blower or a compressor 7, said gas is introduced to a cooler 3 through a duct 8 and cooled, and then the cooled nitrogen gas is introduced from an outlet nozzle 2 through a duct 4 to cool down the catalysts in the reaction vessel 1. The nitrogen gas cooled the catalysts is exhausted out of an inlet nozzle 5 of the vessel, led into a duct 6 and circulated repeatedly.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. The present invention provides a container for replacing or regenerating a catalyst (i.e., a waste catalyst) in a reaction container used in various chemical reactions. The present invention relates to a method for cooling a catalyst to facilitate extraction work when the catalyst is extracted from a catalyst.

Conventional 1 (between r and point -a) Catalysts used for chemical reactions decrease in activity due to poisoning of carbides, metals, etc., and fracture due to decrease in mechanical strength. Otherwise, it is necessary to carry out regeneration treatment, and for this purpose it is necessary to take out the spent catalyst from the reaction vessel.

However, conventionally, when removing the used catalyst from the reaction vessel, steam, steam,
Carbide etc. are completely burned in the reaction vessel with air,
A method has been used in which the catalyst is then extracted, but since the catalyst is burned inside the reaction vessel, it takes a long time and, in addition, there are problems such as the generation of SOX and the like during the combustion. Also, - direction,
For large reaction vessels, there are two methods: - When shutting down when replacing the catalyst, there is a method of passing low temperature liquid through the catalyst bed to cool the catalyst temperature to a considerably low temperature and then extracting it, and a method of supplying nitrogen gas into the reaction vessel. However, methods are being used to prevent heat generation due to oxidation of the catalyst and extract it by keeping the catalyst under a nitrogen atmosphere and shielding it from air.

However, in the former method, the catalyst temperature is determined by the ability of the cooler to cool the liquid and the outside temperature, so it is difficult to lower the temperature to the desired temperature, and there are problems in that the cost of cooling equipment is high. As the work is carried out under a nitrogen atmosphere, safety management measures are required during the work.
On the other hand, it is difficult to sufficiently shield the catalyst from the air, so there is a problem that heat generation of the catalyst cannot be effectively prevented.

Recently, a method has been proposed in which the catalyst is extracted from the upper part of the reaction vessel using a vacuum suction type unloader (so-called top extraction method) (Japanese Patent Application Laid-Open No. 61-35841).
Even with this method, if the extraction process continues for a long time, the catalyst will generate heat (temperature rises at a rate of several degrees Celsius per day).
There's a problem.

The present invention relates to an efficient method for cooling a catalyst in order to facilitate the removal of spent catalyst from a reaction vessel, and the present invention relates to a method for efficiently cooling a catalyst that has generated heat in a reaction vessel in a safe and simple manner. It is an object of the present invention to provide a method for cooling a catalyst, which allows the catalyst to be cooled by a simple operation, without deteriorating the working environment due to the generation of H1s, so-o, etc., and by which the catalyst can be extracted under normal atmospheric conditions.

The present invention will be explained in detail below.

A feature of the present invention is that when extracting the catalyst from the reaction vessel,
The purpose is to introduce a cooled inert gas into the reaction vessel and repeat this operation in a circulation manner to cool the catalyst within the reaction vessel.

As mentioned above, the present invention for cooling buds efficiently cools the catalyst in the reaction vessel by introducing the inert gas into the reaction vessel while cooling and circulating it. Nitrogen gas, carbon dioxide gas, etc. can be used as the inert gas.

In the present invention, in order to cool the inert gas and introduce it into the reaction vessel while circulating it, a circulation line is formed that connects the inlet nozzle and outlet nozzle conduit of the reaction vessel, and in this circulation line there is no inert gas. It is preferable to install a cooler near the inlet nozzle of the active gas container to cool the circulating inert gas.The cooler used here can be a general refrigerator or a refrigerator via a pline.

In addition, in order to prevent air from entering the inert gas being circulated, the connection between the circulation system path and the reaction vessel should be sufficiently sealed, and if necessary, a damper may be used to close the circulation system path. It is necessary to control the amount of inert gas in order to keep the circulation system airtight and maintain a positive pressure inside the circulation system.To do this, the required amount of inert gas must be introduced into the system at the beginning and during operation. Although it is good to introduce inert gas, the amount of inert gas used is small because it is circulated.

Note that the most effective time to cool the catalyst is before the catalyst is taken out from the reaction vessel.
Cooling to 0 to 20°C has the effect of suppressing heat generation due to contact between the catalyst and air to such an extent that it does not interfere with removal of the catalyst.

As described above, according to the present invention, the catalyst in the reaction vessel can be effectively cooled by a simple operation consisting of circulating a small amount of inert gas, cooling it, and introducing it into the reaction vessel. It can also be used in combination with methods for preventing oxidation.

For example, if the method is combined with a method of preventing oxidation by moistening the catalyst with light oil or the like or a conventional method of preventing oxidation of the catalyst under a nitrogen gas atmosphere, the removal of the catalyst can be carried out very safely. Furthermore, if the cooling method according to the present invention is used at night when the catalyst removal work is not performed, the catalyst will only rise by about a few degrees Celsius per day, as described above, so that the catalyst removal work can be carried out efficiently. Can be done.

Furthermore, the cooling method according to the present invention can be used at any time depending on the heat generation state of the catalyst before and after the start of the catalyst extraction operation. Vacuum unloader by method
It has the advantage that work can be performed under atmospheric conditions even when using

The present invention will be specifically explained below using Examples.

EXAMPLES The outline of the apparatus used for carrying out the present invention will be explained based on the attached drawings which illustrate the outline of the apparatus. In the drawings, reference numeral 1 denotes a reaction vessel, an outlet nozzle 2 of which is connected to a conduit 4, The conduit 4 is connected to a conduit 6 via a cooler 3, and the inlet nozzle 5 of the reaction vessel 1 is connected to the conduit 6. 7 in the figure is a blower for circulating inert gas. Alternatively, it is a compressor, and the conduit 6 is connected to its suction port. Also, 8 is a blower or compressor 7
9 is a conduit connecting the discharge port of the reactor and the cooling pipe 3, and 9 indicates a flow N adjustment valve for introducing the inert gas 10 into the reaction vessel 1 through the conduits 6 and 4.

In order to cool the catalyst in the reaction vessel l using the above-mentioned apparatus prior to its extraction operation, nitrogen gas 10 as an inert gas is introduced into the conduit 6, and the pressure in the circulation system of the apparatus is slightly (0.0
, 1~0.3kg/cd G) Flow to be positive!
Nitrogen gas flows in through the ffl regulating valve 9, is discharged from the blower (or compressor) 7, is guided to the cooler 3 through the conduit 8 for cooling, and then passes through the conduit 4 and exits the outlet nozzle 2 of the reaction vessel to cool the nitrogen gas. to cool the catalyst in the reaction vessel. The nitrogen gas that has cooled the catalyst flows out from the inlet nozzle 5 of the container and is guided into the conduit 6, whereupon it is repeatedly circulated as described above.

In addition, as in this example, by introducing nitrogen gas for cooling the catalyst into the reaction vessel using the outlet line and inlet line of the reaction vessel, the state of nitrogen gas dispersion within the reaction vessel can be improved. Therefore, the catalyst can be cooled uniformly.

Reference numeral 11 in the figure indicates a pumper for sufficiently blocking air within the system.

According to the above embodiment, the amount of nitrogen gas circulated is 50 to 100N.
rrr/sin, and if a fluorocarbon refrigerator (refrigerator capacity 50KW) is used as the cooler 3, the catalyst capacity is 150.
The temperature of the catalyst decreases by about 20℃ when the cooling time is 10 hours at rd.
Met.

[Brief explanation of drawings]

The attached figures schematically illustrate an apparatus for carrying out the method according to the invention. In the figure, 1−・−・−・−・−・・−・−Reaction container 2−・・・・−
---1---------・----- Reaction vessel outlet nozzle 3
・・・・・・−−−−−−・−・−11−−−−Cooler 4.6.8・・・・−Conduit

Claims (1)

[Claims] (1) To extract the catalyst in the reaction vessel, the catalyst in the reaction vessel is cooled by repeatedly introducing a cooled inert gas into the reaction vessel in a circulation method. cooling method.