Active coke desulfurization and denitration dust combined treatment system

Abstract

The present application relates to the technical field of flue gas purification, and particularly relates to a combined active coke desulfurization and denitration and dust removal system, which is provided with a desulfurization device and a denitration device in sequence along the flue gas flow direction, a dust removal bag is arranged in the denitration reactor, the dust removal bag seals the outlet end of the denitration reactor, so that the flue gas is filtered by the dust removal bag and then discharged, and the denitration reactor is provided with a micro-powder catalyst for denitration reaction and capable of being attached to the dust removal bag. The dust removal bag is arranged in the denitration reactor, and the catalyst dust entrained by the flue gas is filtered after the flue gas is denitrated; the dust removal mechanism is arranged in the denitration chamber, the catalyst attached to the surface of the dust removal bag can make the flue gas and the reducing agent perform secondary contact, and the desulfurization and denitration effect and the dust removal effect are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of flue gas purification, and in particular to an active coke desulfurization and denitrification combined treatment system. BACKGROUND

[0002] Currently, the active coke (or activated carbon, hereinafter the same) dry desulfurization technology mainly adopts columnar active coke desulfurization and denitrification. A large amount of active coke dust is generated in the active coke material conveying process, resulting in excessive flue gas emission dust. If a dust removal device is connected in series after denitrification, the resistance of the entire system is very large, so adding a dust removal device is not economical and requires a large site. In addition, the traditional active coke desulfurization device has a rectangular cross section, and the flue gas flow field distribution is poor. A large amount of flue gas is shunted through the area with low air pressure. In order to meet the environmental protection emission requirements, the volume of the entire desulfurization and denitrification device has to be enlarged. In terms of wind resistance, the structure with a rectangular outer surface has a large force receiving area because its windward surface is planar, and the wind force is difficult to disperse, so the wind force received is also large. Therefore, the outer surface of the rectangular structure is often provided with dense steel to offset the influence of the wind force. The internal pressure of the desulfurization device is generally three to four thousand pascals, and when the system resistance increases, the outer wall plate of the device also needs to be thickened, which further increases the investment of the dry active coke desulfurization device.

[0003] Therefore, it is necessary to solve the above technical problems. SUMMARY

[0004] In order to solve the above technical problems, the present application provides an active coke desulfurization and denitrification combined treatment system. The desulfurization reactor is in a tower type structure, and large particle active coke is used for desulfurization. The active coke dust particles with a larger specific surface area generated in the desulfurization process are used for denitrification. The active coke dust attached to the surface of the filter bag is used for further catalytic denitrification. The filter bag is used for filtering flue gas, and the problem of excessive dust emission is solved at the same time.

[0005] The technical scheme provided by the present application is as follows:

[0006] An active coke desulfurization and denitrification combined treatment system comprises:

[0007] A desulfurization reactor and a denitrification reactor are arranged along the flue gas flow direction;

[0008] A dust removal bag is arranged in the denitrification reactor, and the outlet end of the denitrification reactor is closed by the dust removal bag, so that the flue gas is filtered by the dust removal bag and then discharged;

[0009] The denitrification reactor has a micro-powder catalyst for denitrification reaction and attached to the dust removal bag.

[0010] In some embodiments, a micro-powder circulation system is further included.

[0011] The micro-powder circulation system comprises a micro-powder storage hopper and a conveying fan;

[0012] The micro-powder storage hopper is in communication with the interior of the denitration reactor and is used to collect the deposited micro-powder catalyst;

[0013] The micro-powder storage hopper is also in communication with the conveying fan, and the micro-powder catalyst in the micro-powder storage hopper is conveyed to the interior of the denitration reactor by the conveying fan.

[0014] In some embodiments, the denitration reactor has an ash hopper, and the ash hopper serves as the micro-powder storage hopper;

[0015] A micro-powder conveying pipeline in communication is provided between the ash hopper and the conveying fan.

[0016] In some embodiments, the ash hopper is inverted conical.

[0017] In some embodiments, the desulfurization reactor has a cylindrical side wall, and the interior of the cylindrical side wall has a moving bed reactor;

[0018] The moving bed reactor is attached with activated coke particles.

[0019] In some embodiments, a regeneration system is further included;

[0020] The regeneration system comprises a regeneration tower, which is used to restore the adsorption performance of activated coke discharged from the bottom of the desulfurization reactor and then reuse the activated coke to the feed at the top of the desulfurization reactor.

[0021] In some embodiments, the regeneration system further comprises a vibrating screen and a storage bin;

[0022] The desulfurization adsorbent is columnar activated coke.

[0023] The vibrating screen is arranged at the discharge port end of the regeneration tower and performs vibrating screening of the regenerated activated coke according to different particle sizes.

[0024] The screened powder activated coke is conveyed to the storage bin to provide the micro-powder catalyst.

[0025] The screened granular activated coke is conveyed to the desulfurization reactor.

[0026] In some embodiments, the desulfurization reactor and the denitration reactor are in communication through a flue gas duct;

[0027] An ammonia injection grid is arranged in the flue gas duct, and the ammonia injection grid is in communication with an external ammonia station system to provide ammonia gas.

[0028] The flue gas duct is further connected with a conveying pipeline for conveying the fine catalyst, and the fine catalyst is sent into the interior of the denitration reactor through the conveying pipeline.

[0029] In some embodiments, one end of the conveying pipeline in communication with the flue gas duct is provided with a fine powder distributor.

[0030] In some embodiments, the top of the dust removal bag is provided with a blowing device.

[0031] Compared with the prior art, the present application has the beneficial effects of:

[0032] (1), the present application realizes the combined treatment of flue gas by sequentially arranging the desulfurization reactor and the denitration reactor;

[0033] (2), the active coke desulfurization reactor of the present application adopts a tower type structure with low resistance, and the outer wall of the desulfurization reactor is in a cylindrical structure, compared with the rectangular cross-section adsorption tower, the rectangular wall plate structure reinforcing steel column is saved, and the tower construction cost is greatly saved;

[0034] (3), the present application sets a dust removal bag in the denitration reactor, which filters the catalyst dust carried by the flue gas after flue gas denitration; the dust removal mechanism is arranged in the denitration chamber, which reduces the floor area, and the catalyst attached to the surface of the dust removal bag can also make the flue gas contact with the reducing agent again, improving the denitration effect;

[0035] (4), the present application realizes the reuse of the denitration catalyst by the fine powder circulation system after participating in the denitration reaction;

[0036] (5), the present application improves the specific surface area of the reused desulfurization adsorbent by grinding treatment, and improves the denitration effect;

[0037] (6), in the present application, the active coke particles restore the adsorption performance through the regeneration tower, realizing the reuse of the adsorbent. BRIEF DESCRIPTION OF DRAWINGS

[0038] The present application will be further described in detail below in combination with the drawings and specific embodiments:

[0039] Figure 1 is a schematic diagram of an active coke desulfurization and denitration dust removal combined treatment system in an embodiment of the present application.

[0040] Figure 2 is a structural front view of the desulfurization reactor in an embodiment of the present application;

[0041] Figure 3 is a structural plan view of the desulfurization reactor in an embodiment of the present application;

[0042] EXPLANATION OF REFERENCE NUMBERS:

[0043] 100, desulfurization reactor; 110, inlet flue; 111, induced draft fan; 120, flue gas duct; 130, regenerator; 131, vibrating screen; 200, denitration reactor; 210, dust removal bag; 220, conveying fan; 230, ash hopper; 240, fine powder conveying pipeline; 250, injection device; 260, ammonia injection grid; 270, fine powder distributor; 300, storage bin; 310, fine powder grinder. DETAILED DESCRIPTION

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, specific embodiments of the present application will be described below with reference to the drawings. Obviously, the drawings in the following description only represent some embodiments of the present application, and for those skilled in the art, other drawings can be obtained from these drawings without creative labor, and other embodiments can also be obtained.

[0045] In order to make the drawing simple, only the parts related to the invention are shown in each drawing, which does not represent the actual structure of the product. In addition, in order to make the drawing simple and easy to understand, in some drawings, only one of the components with the same structure or function is shown schematically, or only one of them is marked. In this paper, "one" not only means "only one", but also means "more than one".

[0046] It should be further understood that the term "and / or" used in the specification and claims of the present application means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0047] In this paper, it should be noted that unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0048] In addition, in the description of the present application, the terms "first", "second" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0049] Reference Figure 1The application provides an active coke desulfurization and denitration combined treatment system, which is provided with a desulfurization reactor 100 and a denitration reactor 200 along the flow direction of flue gas; a dust removal bag 210 is arranged in the denitration reactor 200, the dust removal bag 210 seals the outlet end of the denitration reactor 200, so that the flue gas is filtered through the dust removal bag 210 and then discharged; the denitration reactor 200 is provided with a micro-powder catalyst for a denitration reaction and capable of being attached to the dust removal bag 210. As a preferred embodiment, the micro-powder catalyst is active coke powder, and the particle size is less than 100 μm, and more preferably, the particle size is 20-25 μm. The micro-powder catalyst enters the denitration reactor 200 along with the flue gas flow, the flue gas is filtered through the dust removal bag 210 after the denitration reaction, the micro-powder catalyst is blocked and attached to the surface of the dust removal bag 210 to form a filter cake filter layer with a certain thickness, and the flue gas is further catalytically removed of NOX while being filtered through the filter cake, and the secondary catalytic reaction of reactants is carried out.

[0050] In the embodiment, the active coke powder is used as the catalyst, and compared with the active coke particles, the active coke powder has a larger specific surface area and a higher catalytic efficiency. In the desulfurization section, the active coke particles fall from the upper part to the lower part in the desulfurization reactor 100 under the action of gravity, the flue gas rises from the lower part to the upper part, the active coke particles and the flue gas are in countercurrent or cross flow contact, and desulfurization is realized. After the desulfurization, the flue gas continues to rise into the subsequent denitration section, is denitrated by reacting with ammonia gas, and the purified flue gas is discharged through the chimney after being collected in the clean flue. In the denitration section, the active coke particles do not need to be regenerated, can be crushed and ground, the contact catalytic area is increased, the denitration catalytic effect is further improved, the outlet end of the denitration reactor 200 is connected with the clean flue in the embodiment, and the filtered clean flue gas enters the chimney for discharge.

[0051] In some embodiments of the application, the dust removal bag 210 is provided in a plurality of forms, and the plurality of dust removal bags 210 are arranged in the denitration reaction chamber to improve the flue gas filtering efficiency.

[0052] In some embodiments of the application, a micro-powder circulation system is further included; the micro-powder circulation system comprises a micro-powder storage hopper and a conveying fan 220; the micro-powder storage hopper is communicated with the inside of the denitration reactor 200 and is used for collecting the deposited micro-powder catalyst; wherein the micro-powder storage hopper can be arranged in the inside of the denitration reactor 200 or can be independently arranged additionally; the micro-powder storage hopper is further communicated with the conveying fan 220, the micro-powder catalyst in the micro-powder storage hopper is conveyed to the inside of the denitration reactor 200 by the conveying fan 220 and is used as the catalyst for the denitration reaction. In the embodiment, the micro-powder catalyst is active coke powder, and in the denitration reaction, the active coke powder only plays a catalytic role and does not need to be regenerated, so that the active coke powder can be directly recycled and utilized.

[0053] In some embodiments of the present application, the denitration reactor 200 has an ash hopper 230 which also serves as the fine powder storage hopper; a fine powder conveying pipeline 240 is provided between the ash hopper 230 and the conveying fan 220, and the fine powder catalyst in the ash hopper 230 is conveyed into the denitration reactor 200 by the conveying fan 220 and used as a catalyst for the denitration reaction. The fine powder catalyst collected in the ash hopper 230 can be conveyed into the storage bin 300 by the conveying fan 220 in an emergency state.

[0054] In some embodiments of the present application, the ash hopper 230 is an inverted cone with a large upper opening and a small lower opening, which facilitates dust collection and dust discharge.

[0055] In some embodiments of the present application, the desulfurization reactor 100 is a moving bed reactor; active coke particles are continuously added to the top of the desulfurization reactor 100 and discharged from the bottom; flue gas is introduced into the bottom of the desulfurization reactor 100 and contacts the active coke particles. The flue gas is pressurized by the induced draft fan 111 and introduced into the desulfurization reactor 100 through the gas inlet flue 110 to contact the active coke particles, and SO2 in the flue gas undergoes adsorption and catalytic oxidation on the surface of the active coke particles to achieve desulfurization. As a preferred embodiment, the active coke particles are columnar large particles with a particle size of 8-9 mm, high mechanical strength, high ignition point, and good air permeability. The temperature of the flue gas introduced by the induced draft fan 111 is 110-150°C. Reference Figure 2 With Figure 3 In this embodiment, the desulfurization reactor 100 is a self-standing adsorption tower with a cylindrical side wall and a moving bed reactor inside, and a storage chamber is provided at the top as needed, the moving bed reactor is attached with active coke particles, and the flue gas contacts the active coke particles in counterflow or crossflow. Preferably, the moving bed reactor uses a screen or perforated plate to fix the active coke particles, which eliminates the structural reinforcement steel columns of the rectangular wall panels compared to the adsorption tower with a rectangular cross section, greatly saving the tower construction cost. The induced draft fan 111 introduces flue gas into the desulfurization reactor 100, the flue gas in the tower independently undergoes desulfurization reaction, and then is combined through the flue gas duct 120, and then undergoes nitration reaction after mixing with ammonia and coke powder. The active coke particles discharged from the bottom of multiple desulfurization reactors 100 are connected in parallel and introduced into the regeneration tower 130 for regeneration, and then introduced into each tower from the upper inlet.

[0056] In some embodiments of the present application, a regeneration system is further included; the regeneration system includes a regeneration tower 130 for recovering the adsorption performance of the activated coke discharged from the bottom of the desulfurization reactor 100 and recycling the activated coke to the top of the desulfurization reactor 100. The top inlet end of the regeneration tower 130 is connected to the activated coke discharge end of the bottom of the desulfurization reactor 100, and the bottom outlet end of the regeneration tower 130 is connected to the activated coke feeding port of the top of the desulfurization reactor 100; the regeneration tower 130 desorbs and regenerates the adsorbent discharged from the desulfurization reactor 100, and the regenerated activated coke particles and fresh activated coke particles are fed into the desulfurization reactor 100. Preferably, the activated coke regenerated by the regeneration tower 130 is screened into coke powder and activated coke particles with a particle size of 8-9 mm by a vibrating screen 131, the screened coke powder is fed into a storage bin 300, and the screened activated coke particles are fed into the desulfurization reactor 100 together with fresh activated coke particles.

[0057] In some embodiments of the present application, the regeneration system further includes a vibrating screen 131 and a storage bin 300; the desulfurization adsorbent is columnar activated coke; the vibrating screen 131 is arranged at the discharge port end of the regeneration tower 130 and screens the regenerated activated coke into different particle sizes; the screened powder activated coke is transported to the storage bin 300 to provide the micro-powder catalyst; and the screened granular activated coke is transported to the desulfurization reactor 100. In this embodiment, a micro-powder grinder 310 is further arranged. The material at the outlet end of the storage bin 300 is ground by the micro-powder grinder 310 to below 100 μm and then transported to the denitration reactor 200 for use as a catalyst; as a preferred embodiment, the particle size of the micro-powder catalyst is 20-25 μm. After grinding, the catalyst forms a micro-powder state with a larger specific surface area. When the denitration system is initially put into operation, the catalyst is directly added to the denitration reactor 200 through the micro-powder storage hopper; after the system is stably operated, the micro-powder storage hopper receives the micro-powder catalyst discharged from the denitration reactor 200 and the micro-powder catalyst screened by the vibrating screen 131, and transports the micro-powder catalyst to the denitration reactor 200, thereby achieving dynamic material balance.

[0058] In some embodiments of the present application, the desulfurization reactor 100 and the denitration reactor 200 are communicated through a flue gas duct 120; the flue gas duct 120 is provided with an ammonia injection grid 260, which is communicated with an external ammonia station system to provide ammonia gas; the flue gas duct 120 is further connected with a conveying pipeline for conveying the fine catalyst, and the fine catalyst is sent into the denitration reactor 200 through the conveying pipeline. The flue gas in the flue gas duct 120 is mixed with ammonia gas and fine catalyst to form a mixed gas stream, and is conveyed into the denitration reactor 200, and after the catalytic reaction in the denitration reactor 200, the mixed gas stream is filtered through a dust bag 210. In the embodiments of the present application, the ammonia injection grid 260 adopts a gas distributor or a liquid distributor, and the conveying pipeline of the fine catalyst is provided with a fine powder distributor 270 at the end. As a preferred embodiment, the ammonia injection grid 260 sprays ammonia gas into the flue, which is mixed with the flue gas flowing from bottom to top; wherein, the ammonia injection grid 260 can spray ammonia gas, or can spray ammonia water or other ammonia sources. The fine powder distributor 270 at the end of the fine catalyst is arranged on a horizontal flue duct, and the fine powder distributor 270 uniformly distributes the catalyst in the flue, which is catalytically reduced with NOx in the flue gas. As a preferred embodiment of the flue gas duct 120, the flue gas, catalyst and ammonia gas are fully mixed under the premise of prolonging the reaction distance.

[0059] In some embodiments of the present application, the dust bag 210 is provided with a blowing device 250 inside, which is used for blowing and cleaning the dust bag 210 at a certain time or pressure, so as to blow off the surface filter cake to reduce the system resistance. As a preferred embodiment, the blowing device 250 adopts a rotary blowing or pulse blowing.

[0060] It should be noted that the above embodiments can be freely combined according to needs. The above is only a preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, which should be considered as the protection scope of the present application.

Claims

1. An active coke desulfurization and denitrification combined treatment device, characterized in that, The application relates to an active coke desulfurization and denitration combined treatment device. The device comprises a desulfurization reactor and a denitration reactor arranged along the flue gas flow direction. The desulfurization reactor has a cylindrical side wall, and a moving bed reactor is arranged in the interior of the desulfurization reactor. Active coke particles are attached to the moving bed reactor, the active coke particles are continuously added to the top of the desulfurization reactor and discharged from the bottom, the bottom of the desulfurization reactor is pressurized by an induced draft fan, flue gas is introduced into the flue gas through the induced draft fan, and the active coke particles are contacted. A dust removal bag is arranged in the denitration reactor, the dust removal bag seals the outlet end of the denitration reactor, so that the flue gas is filtered through the dust removal bag and discharged. The denitration reactor has a micro-powder catalyst for denitration reaction and attached to the dust removal bag, the micro-powder catalyst is active coke powder. The active coke desulfurization and denitration combined treatment device further comprises a micro-powder circulation system and a regeneration system. The micro-powder circulation system comprises a micro-powder storage hopper and a conveying fan, the micro-powder storage hopper is communicated with the interior of the denitration reactor and used for collecting the deposited micro-powder catalyst, the micro-powder storage hopper is further communicated with the conveying fan, and the micro-powder catalyst in the micro-powder storage hopper is conveyed to the interior of the denitration reactor by the conveying fan. The regeneration system comprises a regeneration tower, a vibrating screen and a storage bin, the regeneration tower is used for recovering the adsorption performance of the active coke discharged from the bottom of the desulfurization reactor and recycling the active coke to the top of the desulfurization reactor, the vibrating screen is arranged at the discharge port end of the regeneration tower and used for vibrating screening the regenerated active coke into different particle sizes. The screened powder active coke is conveyed to the storage bin to provide the micro-powder catalyst, and the screened granular active coke is conveyed to the desulfurization reactor. A micro-powder grinder is further arranged, and the material at the outlet end of the storage bin is ground by the micro-powder grinder to below 100 mu m and then conveyed to the denitration reactor.

2. The active coke desulfurization and denitration combined treatment device according to claim 1, wherein the denitration reactor has an ash bucket, and the ash bucket is used as the micro-powder storage hopper. A micro-powder conveying pipeline is arranged between the ash bucket and the conveying fan.

3. The active coke desulfurization and denitration combined treatment device according to claim 2, wherein the ash bucket is a reverse conical shape.

4. The active coke desulfurization and denitration combined treatment device according to claim 1, wherein the desulfurization reactor and the denitration reactor are communicated through a flue gas duct. An ammonia injection grid is arranged in the flue gas duct, the ammonia injection grid is communicated with an external ammonia station system to provide ammonia gas. A conveying pipeline for conveying the micro-powder catalyst is further connected to the flue gas duct, and the micro-powder catalyst is sent into the interior of the denitration reactor through the conveying pipeline.

5. The active coke desulfurization and denitration combined treatment device according to claim 4, wherein a micro-powder distributor is arranged at one end of the conveying pipeline communicated with the flue gas duct.

6. The active coke desulfurization and denitration combined treatment device according to claim 1, wherein a blowing device is arranged at the top of the dust removal bag. ​ ​ ​ ​ ​

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