JP6848598B2 - How to reuse denitration catalyst - Google Patents

Description

The present invention relates to a method for reusing a denitration catalyst in a combustion facility provided with a denitration device.

At coal-fired power plants, nitrogen oxides are generated during coal combustion, but due to regulations such as the Air Pollution Control Act, the emissions are limited to a certain level or less. Therefore, a flue gas denitration device is installed in the power plant to reduce and decompose nitrogen oxides. This flue gas denitration device is filled with a denitration catalyst, and by coexisting with ammonia (gas), a reduction reaction is exhibited at a high temperature. As this denitration catalyst continues to be used, its performance deteriorates due to thermal deterioration such as sintering, chemical deterioration due to poisoning of catalyst components, and physical deterioration in which soot and dust cover the catalyst surface. , Performance recovery is required, and as the method, replacement with a new catalyst or catalyst regeneration is performed. As a method for regenerating the catalyst, for example, as disclosed in Patent Document 1, an abrasive is put into each space where the catalyst surface of the denitration catalyst is exposed, and then the denitration catalyst is two-dimensionally or three-dimensionally applied. There is a reproduction method of shaking.

Japanese Unexamined Patent Publication No. 2011-161373

In Japan, for example, power plants that require a denitration rate of about 90% and power plants that require a denitration rate of about 80% have different catalytic performance required for denitration catalysts. There is a difference.
Furthermore, in power plants that require a relatively high denitration rate, there are catalysts that need to be replaced even if the denitration rate does not drop significantly, and denitration catalysts generally have a high unit price, so replacement costs are high. Bring.
On the other hand, even in a power plant where a relatively low denitration rate is required, the denitration catalyst is filled only in the amount of the catalyst relative to the amount of exhaust gas, so even if the denitration rate does not decrease significantly, it needs to be replaced. There is a catalyst.

Therefore, an object of the present invention is to provide a method for reusing a denitration catalyst, which can reduce the amount of waste of the used denitration catalyst by more effectively utilizing the used denitration catalyst.

In order to achieve the above object, the present invention includes the following configurations.

(1) A method for reusing a used denitration catalyst in a combustion facility equipped with a denitration device.
The process of confirming the performance of the denitration catalyst used in the first combustion equipment that requires the first denitration rate, and
When the denitration rate of the denitration catalyst is less than the first denitration rate and equal to or more than the second denitration rate required in the second combustion equipment, the step of using the denitration catalyst in the second combustion equipment. When,
A method for reusing a denitration catalyst having.

According to (1), the denitration catalyst can be used more effectively by accommodating the used denitration catalyst between combustion equipments having different required denitration rates.

(2) In the method for reusing the denitration catalyst, when the denitration rate of the denitration catalyst is lower than the second denitration rate, the denitration catalyst is regenerated and then the first combustion equipment or the first combustion facility or the first. 2 It is preferable to further have a process used in the combustion equipment.

According to (2), it is possible to exchange denitration catalysts between combustion equipment, including denitration catalysts that are greatly deteriorated by use.

(3) In the method for reusing the denitration catalyst, it is preferable to polish the denitration catalyst when regenerating the denitration catalyst.

According to (3), it is possible to sufficiently recover the performance of the denitration catalyst at low cost.

(4) In the method for reusing the denitration catalyst, the denitration catalyst is preferably a denitration catalyst having a wall thickness of 0.5 mm or more.

According to (4), since the wall thickness of the denitration catalyst is 0.5 mm or more, the performance of the denitration catalyst can be recovered by polishing and regeneration at low cost, and the total operating cost of the combustion equipment can be reduced.

(5) It is preferable that the method for reusing the denitration catalyst further includes a step of adjusting the denitration catalyst to the specifications of the second combustion equipment before using the denitration catalyst in the second combustion equipment.

According to (5), it is possible to exchange used denitration catalysts even between combustion equipments having different specifications of denitration catalysts actually used.

(6) In the above method for reusing the denitration catalyst, it is preferable that the step of conforming to the specifications of the second combustion equipment includes a step of cutting the catalyst.

According to (6), it is possible to exchange used denitration catalysts even between combustion equipments having different lengths of denitration catalysts actually used. In particular, when polishing the denitration catalyst, the cost required for polishing the denitration catalyst does not depend on the length of the denitration catalyst. Therefore, by polishing the denitration catalyst and then cutting it, the operating cost of the combustion equipment can be reduced. It will be possible.

According to the present invention, by accommodating used denitration catalysts between combustion equipments having different required denitration rates, it is possible to more effectively utilize the used denitration catalysts and reduce the amount of denitration catalysts to be discarded. It will be possible.

It is an overall block diagram of the thermal power generation system which carries out the method of reusing the denitration catalyst which concerns on embodiment of this invention. It is a figure which shows the example of the denitration apparatus provided in the thermal power generation system which carries out the method of reusing the denitration catalyst which concerns on embodiment of this invention. It is a flowchart which shows the reuse method of the denitration catalyst which concerns on embodiment of this invention. It is a figure which shows the operation example of the reuse method of the denitration catalyst which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall configuration diagram of a thermal power generation system 1, which is an example of a combustion facility that executes a method for reusing a denitration catalyst according to the present invention.

As shown in FIG. 1, the thermal power generation system 1 includes a boiler 10 as a combustion device, a pulverized coal machine 20, an exhaust passage L1, an air preheater 30, a gas heater 40 as a heat recovery device, and a dust collector. It includes 50, a denitration device 60, an induction blower 70, a desulfurization device 80, a gas heater 90 as a heater, and a chimney 100.

The boiler 10 burns pulverized coal as fuel together with air. In the boiler 10, exhaust gas is generated by burning pulverized coal. The combustion of pulverized coal produces coal ash such as clinker ash and fly ash. The clinker ash produced in the boiler 10 is discharged to the clinker hopper 11 arranged below the boiler 10 and then transported to a coal ash recovery silo (not shown).

The boiler 10 is formed in a substantially inverted U shape as a whole. The exhaust gas generated in the boiler 10 moves in an inverted U shape along the shape of the boiler 10. The temperature of the exhaust gas near the outlet of the exhaust gas of the boiler 10 is, for example, 300 to 400 ° C.

The pulverized coal machine 20 pulverizes coal supplied from a coal bunker (not shown) to a fine particle size to form pulverized coal. The pulverized coal machine 20 preheats and dries the pulverized coal by mixing the pulverized coal and air. The pulverized coal formed in the pulverized coal machine 20 is supplied to the boiler 10 by blowing air.

The upstream side of the exhaust passage L1 is connected to the boiler 10. The exhaust passage L1 is a flow path through which the exhaust gas generated in the boiler 10 flows.

The air preheater 30 is arranged in the exhaust passage L1. The air preheater 30 exchanges heat between the exhaust gas and the combustion air sent from the push-in type ventilator (not shown), and recovers heat from the exhaust gas. The combustion air is heated in the air preheater 30 and then supplied to the boiler 10.

The gas heater 40 is arranged on the downstream side of the air preheater 30 in the exhaust passage L1. The gas heater 40 is supplied with the exhaust gas that has been heat-recovered by the air preheater 30. The gas heater 40 further recovers heat from the exhaust gas.

The dust collector 50 is arranged on the downstream side of the gas heater 40 in the exhaust passage L1. The exhaust gas that has been heat-recovered by the gas heater 40 is supplied to the dust collector 50. The dust collector 50 is a device that collects soot dust such as coal ash (fly ash) in the exhaust gas by applying a voltage to the electrodes. The fly ash collected by the dust collector 50 is transported to a coal ash recovery silo (not shown). The temperature of the exhaust gas in the dust collector 50 is, for example, 80 to 120 ° C.

The denitration device 60 is arranged on the downstream side of the dust collector 50 in the exhaust passage L1. The denitration device 60 is supplied with exhaust gas after the dust is collected by the dust collector 50. The denitration device 60 removes nitrogen oxides from the exhaust gas by a denitration catalyst. The denitration catalyst used in the denitration device 60 will be described in detail later. The temperature of the exhaust gas in the denitration device 60 is, for example, 130 to 200 ° C.

The denitration device 60 removes nitrogen oxides from the exhaust gas by a selective contact reduction method. According to the selective catalytic reduction method, nitrogen oxides can be efficiently removed from the exhaust gas by producing nitrogen and water from the nitrogen oxides with a reducing agent and a denitration catalyst. The reducing agent used in the selective catalytic reduction method contains at least one of ammonia and urea. When ammonia is used as the reducing agent, ammonia in any state of ammonia gas, liquid ammonia, and aqueous ammonia solution may be used.

More specifically, the denitration device 60 injects ammonia gas into the introduced exhaust gas, and then uses the mixed gas as a honeycomb molded body having a denitration catalyst fixed, an alumina fiber carrying a denitration catalyst, or the like. It can be configured to be in contact with the fibers. A configuration example of the denitration device 60 will be described later.

The induction ventilator 70 is arranged on the downstream side of the denitration device 60 in the exhaust passage L1. The induction ventilator 70 takes in the exhaust gas from which the nitrogen oxides have been removed in the denitration device 60 from the primary side and sends it out to the secondary side.

The desulfurization apparatus 80 is arranged on the downstream side of the induction ventilator 70 in the exhaust passage L1. The exhaust gas sent from the induction ventilator 70 is supplied to the desulfurization apparatus 80. The desulfurization apparatus 80 removes sulfur oxides from the exhaust gas. Specifically, the desulfurization apparatus 80 blows a mixed solution of limestone and water (limestone slurry) onto the exhaust gas to absorb the sulfur oxides contained in the exhaust gas into the mixed solution and remove the sulfur oxides from the exhaust gas. The temperature of the exhaust gas in the desulfurization apparatus 80 is, for example, 50 to 120 ° C.

The gas heater 90 is arranged on the downstream side of the desulfurization apparatus 80 in the exhaust passage L1. The gas heater 90 is supplied with exhaust gas from which sulfur oxides have been removed in the desulfurization apparatus 80. The gas heater 90 heats the exhaust gas. The gas heater 40 and the gas heater 90 heat between the exhaust gas flowing between the air preheater 30 and the dust collector 50 and the exhaust gas flowing between the denitration device 60 and the desulfurization device 80 in the exhaust passage L1. It may be configured as a gas gas heater to be replaced.

The chimney 100 is connected to the downstream side of the exhaust passage L1. The exhaust gas heated by the gas heater 90 is introduced into the chimney 100. Since the exhaust gas introduced into the chimney 100 is heated by the gas heater 90, it is effectively discharged from the upper part of the chimney 100 by the chimney effect. Further, by heating the exhaust gas in the gas heater 90, it is possible to prevent water vapor from condensing above the chimney 100 to generate white smoke. The temperature of the exhaust gas near the outlet of the chimney 100 is, for example, 110 ° C.

FIG. 2 shows a configuration example of the denitration device 60. As shown in FIG. 2, the denitration device 60 includes a denitration reactor 61 and a plurality of stages of denitration catalyst layers 62 arranged inside the denitration reactor 61.

The denitration reactor 61 serves as a field for the denitration reaction in the denitration device 60.
As shown in FIG. 2, the denitration catalyst layer 62 includes, for example, a plurality of honeycomb catalysts 622 as denitration catalysts. More specifically, the denitration catalyst layer 62 includes a plurality of casings 621, a plurality of honeycomb catalysts 622 housed in the plurality of casings 621, and a sealing member 623.

The casing 621 is composed of a square tubular metal member with one end and the other end open. The casing 621 is arranged so that the open one end and the other end face the flow path of the exhaust gas in the denitration reactor 61, that is, the exhaust gas flows through the inside of the casing 621. Further, the plurality of casings 621 are connected and arranged in contact with each other so as to block the flow path of the exhaust gas in the denitration reactor 61.

The honeycomb catalyst 622 is formed in a long shape (rectangular parallelepiped shape) in which a plurality of exhaust gas flow holes 624 extending in the longitudinal direction are formed. The plurality of honeycomb catalysts 622 are arranged so that the extending direction of the exhaust gas flow hole 624 is along the flow path of the exhaust gas. In the present embodiment, the plurality of honeycomb catalysts 622 are arranged inside the denitration reactor 61 in a state of being housed in the casing 621.

The seal member 623 is arranged between the honeycomb catalysts 622 arranged adjacent to each other in the lateral direction to prevent exhaust gas from flowing into the gap between the honeycomb catalysts 622 arranged adjacent to each other. In the present embodiment, the seal member 623 is formed of a conductive sheet-like member, and is formed on one end side and the other end side of the honeycomb catalyst 622 in a predetermined length (for example, 150 mm from the end). It is wrapped around.

As the sealing member 623, ceramic paper composed of inorganic fibers containing alumina or silica as a main component and a binder mixed with conductive fibers or a filler having conductivity can be used.

In the above denitration catalyst layer 62, as the honeycomb catalyst 622, for example, one having a rectangular parallelepiped shape of 150 mm × 150 mm × 860 mm and having 400 (20 × 20) exhaust gas flow holes having an opening of 6 mm × 6 mm is used. Further, as the casing 621, a casing capable of accommodating 72 honeycomb catalysts 622 (6 vertical × 12 horizontal) is used. 120 to 150 casings 621 are used for the denitration catalyst layer 62. That is, 9000 to 10000 honeycomb catalysts 622 are installed in the denitration catalyst layer 62 of one layer.

As will be described later, when the denitration rate of the used denitration catalyst is measured, if the denitration rate is less than 80%, the used catalyst is polished as a regeneration treatment of the used denitration catalyst. In anticipation of this, the wall thickness of the honeycomb catalyst 622 is preferably 0.5 mm or more so that it can withstand polishing. More preferably, the wall thickness of the honeycomb catalyst 622 is 1.0 mm or more. Alternatively, the wall thickness between the cells of the honeycomb catalyst 622 is preferably 20% or more as compared with the outer wall thickness. More preferably, the wall thickness between cells is 40% or more as compared with the outer wall thickness.

Currently, the inventors are polishing about 100 μm as polishing regeneration, but depending on the deterioration condition of the catalyst (thickness of the silica layer), the catalyst performance is the target performance even with polishing of about 50 μm or 10 μm. May recover to.
On the other hand, regarding the wall thickness, the inventors have a track record of polishing a catalyst having an actual measurement of 0.8 mm. The minimum wall thickness of a new catalyst is 0.6 mm, but if the surface layer is polished at a level of 10 μm, a new catalyst with a wall thickness of 0.5 mm will be manufactured in the future. However, I think it can be polished.
From the above, as described above, the wall thickness of the honeycomb catalyst 622 is preferably 0.5 mm or more, and more preferably 1.0 mm or more. Assuming that the outer wall thickness of the honeycomb catalyst 622 is 2.4 mm, the wall thickness between cells is preferably 0.5 / 2.4 = 20% or more, and 1.0 / 2.4 = 40. It is more preferably% or more.

FIG. 3 shows a flow of a method for reusing a used denitration catalyst according to the present invention.
In step S1, the performance of the denitration catalyst used in the first combustion equipment is confirmed. Specifically, for example, one honeycomb catalyst 622 is extracted from each layer of the denitration catalyst layer 62, and the denitration rate of each is measured. As a method for measuring the denitration rate, for example, an NH _3- SCR reaction is carried out using a catalytic reaction device, and the concentrations of _{NO, NH 3} , NO ₂ and N ₂ O in the gas passing through the catalyst layer are measured. , It is possible to calculate the denitration rate using these concentrations.

In step S2, when the denitration rate of the extracted honeycomb catalyst 622 is 90% or more (S2: YES), the process proceeds to step S3. When the denitration rate of the extracted honeycomb catalyst 622 is less than 90% (S2: NO), the process proceeds to step S4.

In step S3, the denitration catalyst layer 62 including the honeycomb catalyst whose denitration rate has been measured continues to be used in the first combustion equipment. After that, the process returns to step S1 (return).

In step S4, when the denitration rate of the extracted honeycomb catalyst 622 is 80% or more (S4: YES), the process proceeds to step S5. When the denitration rate of the extracted honeycomb catalyst 622 is less than 80% (S4: NO), the process proceeds to step S6.

In step S5, the specifications of the total denitration catalyst contained in the denitration catalyst layer 62 including the honeycomb catalyst whose denitration rate was measured are compared with the specifications required for the second combustion equipment, and if necessary, the specifications are obtained at the second combustion equipment. Process according to the specifications to be used.

Specifically, first, the current values of the length of the denitration catalyst and the number of cells are measured and compared with the specifications required for the second combustion equipment. This is because if the catalyst length and the number of cells of the denitration catalyst are different from the use of the existing catalyst of the second combustion facility at the destination, the influence of pressure loss occurs. Specifically, the pressure loss increases in proportion to the increase in the length of the denitration catalyst. In addition, the pressure loss increases in proportion to the square of the increase in the number of cells (increase in the flow velocity in the cell).

Furthermore, the current values are measured and calculated for the AV value, which is the processing gas flow rate value per unit gas contact area of the denitration catalyst, and the LVA value, which is the gas flow velocity in the denitration catalyst layer, and the specifications required for the second combustion equipment. Compare with. Since the amount of processing gas differs depending on the unit, a test is conducted in advance to confirm whether the required performance is satisfied by the gas conditions of the second combustion equipment to which the denitration catalyst is moved, or to confirm the AV value and LVA value. It is a thing.
Here, assuming that the surface area of the denitration catalyst is A (m ² ) and the amount of processing gas is G (m ³ N / h),
AV (m / h) = G (m ³ N / h) / A (m ² )
Will be.
Further, assuming that the cross-sectional area (spatial cross section) of the denitration catalyst layer is Sc (m ² ) and the amount of gas at the treatment temperature is Q (m ³ / s).
LVA (m / s) = Q (m ³ / s) / Sc (m ² )
Will be.

After comparing the specifications of the total denitration catalyst contained in the denitration catalyst layer 62 with the specifications required for the second combustion equipment, a denitration catalyst that does not meet the specifications required for the second combustion equipment is required for the second combustion equipment. It can be processed according to the specifications.
For example, it is possible to cut the denitration catalyst so that the length and the number of cells of the denitration catalyst match the specifications required for the second combustion equipment.
Alternatively, for example, a denitration catalyst that does not meet the specifications required for the second combustion equipment with respect to the AV value and the LVA value can be recovered or pulverized and reused, or can be discarded without being reused.

In step S6, the total denitration catalyst contained in the denitration catalyst layer 62 including the honeycomb catalyst whose denitration rate has been measured is used in the second combustion facility in which the denitration rate required for the denitration catalyst is 80% or more. After that, the process returns to step S1 (return).

In step S7, the entire denitration catalyst contained in the denitration catalyst layer 62 including the honeycomb catalyst whose denitration rate has been measured is regenerated. As the regeneration treatment, it is particularly preferable to polish the denitration catalyst. Specifically, for example, the method for polishing a used denitration catalyst described in Japanese Patent No. 5844943 can be applied.

In step S8, as in step S5, the specifications of the regenerated denitration catalyst are compared with the specifications required for the second combustion equipment, and if necessary, they are processed according to the specifications.
If the denitration catalyst that has been regenerated in step S9, which will be described later, is continuously used in the first combustion equipment, step S8 can be omitted.

In step S9, the denitration catalyst after the regeneration process and, in some cases, processed according to the required specifications is used in the first combustion facility or the second combustion facility. After that, the process returns to step S1 (return).

In the above operation flow, in step S2, it was determined whether or not the denitration rate was 90% or more, and in step S4, it was determined whether or not the denitration rate was 80% or more, but this is just an example. However, the denitration rate, which is the determination criterion in step S2, may be higher than the denitration rate, which is the determination criterion in step S4. Further, the denitration catalyst to be reused in the above reuse method is not limited to the honeycomb catalyst, and may be a denitration catalyst having an arbitrary shape.

FIG. 4 shows an operation example of the method for reusing the denitration catalyst according to the embodiment of the present invention.
In the operation example shown in FIG. 4, the used denitration catalyst 150 used in the combustion equipment 5 of another company is reused in the in-house combustion equipment 10A having a denitration rate of 90% required for the denitration catalyst, and further in-house combustion. The used denitration catalyst 150 used in the equipment 10A shall be reused in the in-house combustion equipment 10C having a denitration rate of 80% required for the denitration catalyst. In parallel with this, the used denitration catalyst 160 used in the combustion equipment 5 of another company is reused in the in-house combustion equipment 10B having a denitration rate of 90% required for the denitration catalyst, and further used in the in-house combustion equipment 10B. It is assumed that the used denitration catalyst 160 used is reused in the in-house combustion equipment 10C having a denitration rate of 80% required for the denitration catalyst. Further, as an example, it is assumed that the length of the denitration catalyst used in the in-house combustion equipment 10A is 860 mm, and the length of the denitration catalyst used in the in-house combustion equipments 10B and 10C is 430 mm.

First, as shown by the flow of the arrow (a) in FIG. 4, the denitration catalyst 150 used in the combustion equipment 5 of another company is inexpensively taken over by the in-house combustion equipment 10A, regenerated, and then in-house combustion. Used in equipment 10A. As described above, it is assumed that the length of the denitration catalyst 150 is 860 mm.

After using the denitration catalyst 150 for a certain period of time in the in-house combustion equipment 10A, the denitration rate is measured, and if the denitration rate is 90% or more, the denitration catalyst 150 is continuously used in the in-house combustion equipment 10A. When the denitration rate of the denitration catalyst 150 is less than 80%, as shown by the flow of the arrow (b), the denitration catalyst 150 is polished and regenerated by the in-house combustion equipment 10A, and the denitration rate of the denitration catalyst 150 after the polishing regeneration is 90%. If the above is the case, it will be used again in the in-house combustion equipment 10A. On the other hand, when the denitration rate of the denitration catalyst 150 after polishing and regeneration is less than 90% but 80% or more, the denitration catalyst 150 having a length of 860 mm is shown by the flow of the arrow (c). Is divided into two denitration catalysts 150A and 150B having a length of 430 mm and reused in the in-house combustion facility 10C.

Although not shown, if the denitration rate after using the used denitration catalyst 150 taken from the combustion equipment 5 of another company for a certain period of time in the in-house combustion equipment 10A is 80% or more and less than 90%, the regeneration treatment is performed. The length of the denitration catalyst 150 is divided into 430 mm and diverted to the in-house combustion equipment 10C.

Further, as shown by the flow of the arrow (d) in FIG. 4, the denitration catalyst 160 used in the combustion equipment 5 of another company is inexpensively taken over by the in-house combustion equipment 10B, regenerated, and then in-house combustion. Used in equipment 10B. As described above, it is assumed that the length of the denitration catalyst 160 is 430 mm.

After using the denitration catalyst 160 in the in-house combustion equipment 10B for a certain period of time, the denitration rate is measured, and if the denitration rate is 90% or more, the denitration catalyst 160 is continuously used in the in-house combustion equipment 10B. When the denitration rate of the denitration catalyst 160 is 80% or more and less than 90%, it is diverted to the in-house combustion equipment 10C as shown by the flow of the arrow (g). When the denitration rate of the denitration catalyst 160 is less than 80%, as shown by the flow of the arrow (e), the denitration catalyst 160 is polished and regenerated by the in-house combustion equipment 10B, and the denitration rate of the denitration catalyst 160 after the polishing regeneration is 90. If it becomes% or more, it will be used again in the in-house combustion equipment 10B.

Further, in the flow of the arrow (e) above, when the denitration rate of the denitration catalyst 160 after polishing and regeneration is less than 90% but 80% or more, it is indicated by the flow of the arrow (g). In addition, it may be diverted to the in-house combustion equipment 10C.

In the in-house combustion equipment 10C, the used denitration catalysts 150A and 150B taken from the in-house combustion equipment 10A and the used denitration catalyst 160 taken from the in-house combustion equipment 10B are used in the denitration device 60. After using the used denitration catalysts 150A, 150B, 160 for a certain period of time, as shown by the flow of the arrow (f), polishing and regeneration is performed by the in-house combustion equipment 10C, and the denitration catalysts 150A, 150B, 160 after polishing regeneration are denitration. If the rate is 80% or more, it will be used again in the in-house combustion equipment 10C.

[Effect of Embodiment]
According to the present embodiment configured as described above, a denitration catalyst having a denitration rate less than the denitration rate required for the first combustion facility is required to have a denitration rate lower than that of the first combustion facility. By using the used denitration catalyst in the second combustion equipment, it is possible to more effectively utilize the used denitration catalyst and reduce the amount of waste of the used denitration catalyst.

In addition, by regenerating a denitration catalyst that has a denitration rate that is less than the denitration rate required for the second combustion facility, used denitration between combustion facilities, including the denitration catalyst that is significantly deteriorated by use. It becomes possible to exchange catalysts with each other.

Further, by polishing the denitration catalyst as a method for regenerating the denitration catalyst, it is possible to sufficiently recover the performance of the denitration catalyst at low cost.

Further, by using a denitration catalyst having a wall thickness of 0.5 mm or more as the denitration catalyst, the performance of the denitration catalyst can be recovered by polishing and regeneration at low cost, and the total operating cost of the combustion equipment can be reduced. ..

In addition, by processing the used denitration catalyst according to the specifications of the second combustion equipment before diverting the used denitration catalyst to the second combustion equipment, the used denitration catalyst can be used even between combustion equipments with different specifications. It becomes possible to exchange catalysts with each other.

Further, when processing the used denitration catalyst according to the specifications of the second combustion equipment, the length of the denitration catalyst actually used is obtained by cutting according to the length of the denitration catalyst used in the second combustion equipment. It is possible to exchange used denitration catalysts even between combustion equipments with different sizes.

[Modification example]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. Further, the effects described in the present embodiment merely list the most preferable effects arising from the present invention, and the effects according to the present invention are not limited to those described in the present embodiment.

For example, in the flowchart shown in FIG. 3, the denitration catalyst determined to have a denitration rate of 90% or more in step S2 is said to continue to be used in the first combustion equipment in step S3, but is not limited thereto. For example. It may be diverted to combustion equipment.

Further, in the flowchart shown in FIG. 3, the denitration catalyst determined to have a denitration rate of 80% or more in step S4 is processed in step S5 according to the specifications required by the second combustion equipment. Is not limited. If the specifications of the denitration catalyst determined to have a denitration rate of 80% or more match the specifications of the denitration catalyst already installed in the second combustion equipment, step S5 is omitted, and in step S6, the second combustion is performed as it is. It can be used in equipment.
Similarly, in step S8, the denitration catalyst regenerated in step S7 is processed according to the specifications required by the second combustion equipment, but the present invention is not limited to this. If the specifications of the regenerated denitration catalyst match the specifications of the denitration catalyst already installed in the second combustion equipment, step S8 can be omitted and the regenerated denitration catalyst can be used as it is in the second combustion equipment in step S9. is there.

Further, in the flowchart shown in FIG. 3, in step S7, as a method for regenerating the used denitration catalyst, a technique for polishing the used denitration catalyst has been described, but the technique is not limited thereto. For example, the used denitration catalyst may be regenerated by coating the surface of the used denitration catalyst with a new denitration catalyst.

Further, in the above embodiment, as an example of the combustion equipment, a method of reusing the denitration catalyst for accommodating the used denitration catalyst between the thermal power generation systems has been described, but the present invention is not limited to this. For example, it can be implemented as a method for reusing a denitration catalyst used in a combustion boiler of a ship or the like.

1 ... Thermal power generation system 10 ... Boiler 60 ... Denitration device 61 ... Denitration reactor 62 ... Denitration catalyst layer 100 ... Chimney 621 ... Casing 622 ... Honeycomb catalyst 623 ... Seal member L1 ... Exhaust path

Claims (5)

It is a method of reusing a used denitration catalyst in a combustion facility equipped with a denitration device.
The denitration rate of the denitration catalyst used in the first combustion facility that requires the first denitration rate is the first denitration rate and the second denitration rate required in the second combustion facility, and the first denitration rate. The process of confirming performance by comparing with the second denitration rate, which is lower than
NOx removal efficiency of the denitration catalyst, when the is first denitration ratio or more, using the denitration catalyst in the first combustion equipment is less than the first denitration rate, is the second denitration rate than In this case, the denitration catalyst is used in the second combustion equipment, and if it is less than the second denitration rate, the denitration catalyst is regenerated and then used in the first combustion equipment or the second combustion equipment. And the process to do
A method for reusing a denitration catalyst having. When reproducing the denitration catalyst is carried out polishing of the denitration catalyst, a method of recycling denitration catalyst according to claim 1. The method for reusing a denitration catalyst according to claim 2 , wherein the denitration catalyst is a denitration catalyst having a wall thickness of 0.5 mm or more. The re-denitration catalyst according to any one of claims 1 to 3 , further comprising a step of adjusting the denitration catalyst to the specifications of the second combustion equipment before using the denitration catalyst in the second combustion equipment. How to Use. The method for reusing a denitration catalyst according to claim 4 , wherein the step of conforming to the specifications of the second combustion equipment includes a step of cutting the denitration catalyst.

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