JPS5962350A - Regenerating method of catalyst - Google Patents

Abstract

PURPOSE:To restore and regenerate easily the deteriorated performance of denitration catalysts when the denitration performance of the catalysts incorporated into a vertical flow type denitration reaction device deteriorates by rinsing the catalysts with water then drying the same with waste gas at high temp. or the like. CONSTITUTION:The gas G to be treated is passed through the body 1 of a vertical flow type denitration device incorporated therein with plural stages of copper catalyst packs 2 of the type packed therein with many catalysts for denitration to remove NOX in the gas with the denitration catalyst. Since the deterioration in the denitration performance owing to deposits arises in the catalysts upon lapse of time, the passage of the gas G is stopped, a nozzle header 8 is positioned to the top surface of the packs 2, water is injected in the form of mists from a nozzle 9 to wash the catalysts and the deposits on the surface are removed. The washing water is discharged from a hopper-shaped draining section 12 through a valve 13 to the outside of the system. Compressed air is blown from the nozzle 9 to the rinsed catalysts to remove moisture, whereafter hot wind is passed from a boiler or the like through the catalysts, whereby the catalysts are dried and regenerated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for regenerating a denitrification catalyst installed in a vertical flow type denitrification reactor while it is still installed in the device.

The denitrification performance of the denitrification catalyst built into the denitrification reactor is
Deteriorates over time. This occurs due to the adsorption of various components, such as heavy oil, alkali metals, etc. in the treatment of boiler exhaust gas, on the catalyst, or the adsorption of dust containing organic matter in the exhaust gas, due to long-term use.

Catalysts whose denitrification performance has deteriorated lose their practical effectiveness, so it is necessary to dispose of them or take measures for economical regeneration.

Conventionally proposed methods for regenerating this catalyst include 7.
Method of firing at 00 to 800°C (Japanese Patent Application Laid-Open No. 50-1557)
No. 87), a method of firing at 100 to 5°C after washing with water (Japanese Patent Application Laid-open No. 155789/1987), etc. Both methods are recognized as effective, but in order to perform these methods, One theory is that the denitrification catalyst must be removed from the nitrification reactor, which requires a very long process time and is economically disadvantageous.

The present invention has been made to eliminate such deficiency A'aj, and provides a method for regenerating a catalyst whose denitrification performance has deteriorated while it is still installed in a denitrification reaction device.

In other words, the present invention provides a method for removing denitrification catalysts that have deteriorated over time and that have been incorporated into a vertical flow type denitrification reaction device, by washing them with water using a water washing device consisting of a permanent part and a temporary part, while still being installed in the equipment. The waste water is discharged to the outside of the p-system through a drainage hopper permanently installed at the bottom of the reactor or an air heater section at the bottom of the reactor, and after completion of water washing, it is dried by the catalytic boiler heat source or the exhaust gas when the boiler is fired. The present invention relates to a method for regenerating a catalyst.

Hereinafter, the method of the present invention will be described in detail with reference to the accompanying drawings.

1 (A), (B) and 2 (A), (B) are diagrams showing examples of vertical flow type denitrification equipment according to the method of the present invention. A downstream method in which the waste G to be processed flows from the upper part of the apparatus to the lower part of the apparatus, Fig. 2 CA-), (B)
This is an upstream type processing gas that flows from the bottom of the G7 device to the top of the device. (B) in each figure is a cross-sectional view, and (A) is a
) is a view taken along the line A and -A.

In Fig. 1 (A), (B) and Fig. 2 (A), (B), 1 is the main body of the vertical flow type denitrification reactor, and 2 is the catalyst pack made of shaped steel built into the device 1. , dozens to hundreds of denitrification catalysts are packed. 5 to 10 are parts related to the flushing device according to the present method, in which the main water supply pipe 3, the gate valve 5, the pressure gauge 6 and the intake port 10 are the permanent part, the flexible port 4, the water supply pipe 7, the nozzle header 8 and the nozzle 9. It is a temporary part, 11 to 13 are drainage means according to the method of the present invention, and 1
Reference numeral 1 denotes a drainage hopper permanently installed in the downstream reaction apparatus 1, and 12 represents an air heater originally installed in the upstream reaction apparatus 1. 16 is a drainage valve which is used as a drainage hopper as it is.

The above-mentioned water washing device first performs the anti-Ic1 washing operation prior to the water washing operation.
Assembling temporary parts within one device. That is, the nozzle header 8 is positioned on the upper surface of the catalyst pack 2 (approximately 500 to 500 mm thick), and the nozzle header 8 is placed so that the nozzle 9 is perpendicular to the catalyst. - Connect 4 flexible hoses to the main water supply pipe 5, insert them into the reactor 1 through the intake hole 10, and connect them to the water supply pipe 7.

After completing the assembly of the soil fertilizer, perform the washing operation.

In the water washing operation, gradually open the gate valve 5, adjust the water pressure to 2 to s kg/era with the pressure gauge 6, and spray from the nozzle 9.
Inject the water into the catalyst. The injected water passes through the drainage hopper 11 or the air heater section 12 and is extracted from the drainage valve 15. The washing time should be set until the amount of poisonous substances such as alkali metals in the wastewater is reduced to almost zero.

When this water washing operation is completed, the pressure 4 from the water supply main 6 is
Compression air of ~5g7'crl? Moisture introduced and remaining in catalyst bag 2? Remove.

After that, connect the tube 8, nozzle 9 and water supply pipe 7 to the nozzle.
Transfer the catalyst pack 2 to the unwashed part shown in Figures 1 (A), (B) and Figure 2 (A), and position the rudder 8 to the nozzle as described above. ?
Hold it vertically and perform the water washing operation and water removal operation 9 as described above.

After performing all of the above operations on Catalyst Pack 2 and washing with water, remove the temporary bamboo parts.
A heat source of the boiler, such as a steam type % type % (FDP), hot air from an air preheater (AH), or exhaust gas at the time of boiler firing, is used to flow through the path of the gas to be treated G in the reaction device 1 for drying. It should be noted that since high-quality fuel such as light oil is used when firing up the boiler, the catalyst is not exposed to much th by the exhaust scum.

In accordance with the above-mentioned operation mode, a denitrification catalyst whose initial performance was 88 units was regenerated to 78 units, and the catalyst was able to perform well after the performance reached 87 units.

At this time, the properties of the gas to be treated flowing before and after the Soo are as follows: Gas temperature: 585"0 Gas composition: Inlet - NOx 1100pp Inlet
SOx was 110 ppm, and the water washing conditions and drying conditions were as follows.

Washing conditions Water quality: Industrial water Quantity: 10 times the apparent volume of the catalyst Water temperature: Room temperature Time = 1 hour Heat used for drying cake = 4! 1200 exhaust gas time when firing a boiler using oil: 1 hour Also, is the above denitrification performance the denitrification rate calculated by the formula below?
This is what is shown.

(However, the inlet NOx level is 0. However, the value is converted to 024 coefficient for the NOx concentration device.) As detailed above, according to the method of the present invention, the denitrification catalyst? It is possible to perform B-generation while being installed in a cross-flow type denitrification reactor, and the time required for regeneration is extremely short, making it extremely economical.

[Brief explanation of drawings]

Figures 1 (B) and &42 Figures 1 (A) and 1 (B) are diagrams showing an example of a vertical flow type denitrification reactor according to the method of the present invention, and (B) in each figure is R view, the figure is A-A in (B)
1) Post-Morning Agent Ryo Hagiwara - (A) (A) 13-1624 Enjoji, Kasamatsu-cho, Hashima-gun, Gifu Prefecture ■Applicant Nippon Insulator Co., Ltd. 2, Suda-cho, Mizuho-ku, Nagoya City No. 56

Claims (1)

[Claims] In a method for regenerating a denitrification catalyst incorporated in a vertical flow type denitrification reaction device, the catalyst is washed with water using a water washing device consisting of a permanent part and a temporary part while the catalyst is installed in the device, and the washing wastewater is used for the reaction. It is characterized by discharging the water out of the p-system through a drainage hopper permanently installed at the bottom of the device or the heater section at the bottom of the reaction device, and drying it with the catalyst boiler heat source or the exhaust gas when the boiler is fired after completion of water washing. A method for regenerating catalysts.