A circulating fluidized bed-based integrated adsorption combustion system and method

Abstract

The application discloses a kind of based on circulating fluidized bed's adsorption combustion integrated system and method, the system includes adsorption device, transport device, storage device and circulating fluidized bed boiler, the adsorption device includes air inlet subassembly and adsorption subassembly, the air inlet subassembly is used to the VOCs into the adsorption subassembly, the adsorption subassembly is multiple, multiple the adsorption subassembly is sequentially communicated and adjacent two the adsorption subassembly is detachably connected, the adsorption subassembly has adsorption cavity, the adsorption cavity is filled with the adsorbent of purifying VOCs, the transport device is used to the adsorbent in the adsorption subassembly is transported to the storage device, the storage device is the circulating fluidized bed boiler and provides the adsorbent to as the fuel of the circulating fluidized bed boiler.The application embodiment based on circulating fluidized bed's adsorption combustion integrated system has the advantages of low cost, simple structure and high efficiency of processing VOCs.

Description

Technical Field

[0001] This invention relates to the field of organic waste gas treatment technology, specifically to an integrated adsorption and combustion system and method based on a circulating fluidized bed. Background Technology

[0002] Volatile organic compounds (VOCs) include non-methane hydrocarbons, oxygenated organic compounds, chlorinated organic compounds, nitrogen-containing organic compounds, and sulfur-containing organic compounds, and are important precursors to PM2.5 and ozone pollution. In recent years, the state has issued several relevant documents requiring further improvement in the scientific nature, targeting, and effectiveness of VOCs control, and in-depth promotion of comprehensive VOCs control in key industries such as petrochemicals, chemicals, industrial coating, packaging and printing, and oil storage, transportation, and sales. Based on the concentration, composition, and volume of exhaust gases, as well as production conditions, appropriate treatment technologies should be developed, and upgrading and transformation should be accelerated.

[0003] In related technologies, fluidized beds are used to achieve continuous adsorption-desorption operation to eliminate VOCs. However, fluidized bed systems have complex structures, and the adsorbent needs to be recycled. After long-term use, the adsorption effect of the adsorbent is poor, making it difficult for fluidized bed components to handle large volumes of organic waste gas. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose an integrated adsorption and combustion system based on a circulating fluidized bed, which has a simple structure and can treat large quantities of organic waste gas.

[0005] The embodiments of the present invention also propose an integrated adsorption and combustion method based on a circulating fluidized bed.

[0006] The integrated adsorption and combustion system based on a circulating fluidized bed according to this invention includes:

[0007] An adsorption device, comprising an air inlet assembly and an adsorption assembly, wherein the air inlet assembly is used to introduce VOCs into the adsorption assembly, and there are multiple adsorption assemblies connected in sequence and adjacent adsorption assemblies are detachably connected, and each adsorption assembly has an adsorption chamber filled with an adsorbent for purifying VOCs.

[0008] A transport device and a storage device, wherein the transport device is used to transport the adsorbent in the adsorption assembly to the storage device;

[0009] A circulating fluidized bed boiler, wherein the storage device provides the adsorbent to the circulating fluidized bed boiler as fuel for the circulating fluidized bed boiler.

[0010] The integrated adsorption and combustion system based on circulating fluidized bed in this invention is particularly suitable for large industrial parks. Distributed adsorption devices can be installed in factories with VOCs treatment needs to centrally transport and store nearly saturated semi-coke particles and send them to the park's own circulating fluidized bed boiler for combustion. The circulating fluidized bed boiler generates heat or electricity for the park's use, thereby realizing large-scale centralized treatment of VOCs and efficient and clean utilization of low-grade resources.

[0011] Therefore, the integrated adsorption and combustion system based on a circulating fluidized bed in this invention has the advantages of low cost, simple structure, and high efficiency in treating VOCs.

[0012] In some embodiments, the adsorption device further includes a track and a moving component. There are multiple moving components, and each of the multiple moving components corresponds to and is connected to a multiple adsorption components. The moving component cooperates with the track and can drive the adsorption components to move along the track.

[0013] The track extends in a series of stations, from the first station to the second station to the (n+1)th station, and each station can accommodate one of the adsorption components.

[0014] In some embodiments, the air intake assembly is disposed at the first work station, and the air intake assembly has an air intake pipe, a first branch and a second branch. One end of the first branch and one end of the second branch can be connected to the air intake pipe, and the other end of the first branch and the other end of the second branch can be connected to the adsorption chamber.

[0015] In some embodiments, the adsorption device has a first state and a second state. In the first state, the second branch is disconnected from the air inlet pipe, the air inlet pipe is connected to the adsorption chamber at the first station through the first branch, and the adsorption chambers at the first station to the nth station are connected sequentially.

[0016] In the second state, the adsorption component on the first station is detached from the first station, the first branch is disconnected from the air inlet pipe, the air inlet pipe is connected to the adsorption chamber on the second station through the second branch, and the adsorption chambers on the second station to the nth station are connected sequentially.

[0017] In some embodiments, the adsorption device further has a third state and a fourth state. In the third state, the adsorbent in the adsorption component at the first station is replaced, the adsorption component at the first station is moved to the (n+1)th station, and the adsorption chamber at the (n+1)th station is connected to the adsorption chamber at the nth station.

[0018] In the fourth state, the adsorption components at the second station to the (n+1)th station are all moved forward one station, the second branch is disconnected from the air inlet pipe, the air inlet pipe is connected to the adsorption chamber at the first station through the first branch, and the adsorption chambers at the first station to the nth station are connected sequentially.

[0019] In some embodiments, the adsorption device further includes an exhaust assembly, which includes an exhaust pipe and an induced draft fan. One end of the exhaust pipe is connected to the adsorption chamber at the nth or n+1th workstation, and the other end of the exhaust pipe is connected to the induced draft fan, which is used to discharge the purified gas.

[0020] In some embodiments, the adsorption device further includes a gas analyzer. The adsorption chamber is provided with a waste gas inlet and a waste gas outlet. A first concentration detection point is provided at the waste gas inlet, and a second concentration detection point is provided at the waste gas outlet. Both the first concentration detection point and the second concentration detection point are connected to the gas analyzer. When the difference between the values ​​of the first concentration detection point and the second concentration detection point is less than 20%, it indicates that the adsorbent in the adsorption chamber has reached adsorption saturation.

[0021] In some embodiments, the circulating fluidized bed boiler is provided with a secondary air inlet, the storage device includes a storage chamber, the storage chamber is provided with an air outlet, and the air outlet is connected to the secondary air inlet.

[0022] The integrated adsorption and combustion method based on a circulating fluidized bed according to embodiments of the present invention includes:

[0023] VOCs are purified using the adsorbent in the adsorption device.

[0024] When the adsorbent at the first station is saturated, the adsorbent at the first station is transported to the storage device;

[0025] Replace the adsorbent in the adsorption component at the first station, and move the adsorption component at the first station to the (n+1)th station;

[0026] Move the adsorption components from the second station to the (n+1)th station forward one station, and repeat the above steps;

[0027] The adsorbent in the storage device is transported to the circulating fluidized bed boiler as fuel.

[0028] The integrated adsorption and combustion method based on circulating fluidized bed in this invention uses semi-coke directly as an adsorbent. After one adsorption saturation, it can be used as fuel for the circulating fluidized bed boiler, thus eliminating the need for adsorption-desorption cycles. This not only simplifies the structure of the circulating fluidized bed boiler and makes operation simple, but also eliminates the need for adsorbent recycling, resulting in higher safety performance and enabling the treatment of large quantities of VOCs.

[0029] In some embodiments, the circulating fluidized bed boiler includes:

[0030] The furnace body has a combustion chamber and is provided with a primary air inlet, a secondary air inlet, a flue gas outlet, and a return material outlet.

[0031] A feeding hopper, which is connected to the furnace body and communicates with the combustion chamber;

[0032] A feeding assembly for conveying the adsorbent in the storage device to the feeding hopper;

[0033] A separator, one end of which is connected to the flue gas outlet and the other end of which is connected to the return port;

[0034] The adsorbent is semi-coke, the particle size of which is 2mm-6mm and the median diameter of which is less than or equal to 3.5mm.

[0035] The temperature inside the combustion chamber is 870℃-910℃, with a bed temperature deviation of less than or equal to 20℃, and the fluidization velocity inside the combustion chamber is 4.0m / s-4.5m / s;

[0036] The oxygen content of the flue gas at the outlet of the separator is 3.5%-4.5%, the cutting particle size of the separator is d50≤15μm, and the critical particle size of the separator is d99≤75μm;

[0037] The airflow entering the combustion chamber from the primary air inlet accounts for 40%-70% of the total airflow entering the combustion chamber from the primary air inlet and the secondary air inlet. Attached image description:

[0038] Figure 1 This is a schematic diagram of an integrated adsorption and combustion system based on a circulating fluidized bed, according to an embodiment of the present invention.

[0039] Figure 2 This is a schematic diagram of the adsorption device of the integrated adsorption and combustion system based on a circulating fluidized bed, according to an embodiment of the present invention.

[0040] Figure 3 This is a schematic diagram of the adsorption component of the integrated adsorption and combustion system based on a circulating fluidized bed according to an embodiment of the present invention.

[0041] Figure label:

[0042] An integrated adsorption and combustion system based on a circulating fluidized bed 100; an adsorption device 1; an air intake assembly 11; an air intake pipeline 111; a first branch 112; a second branch 113; and a first valve 114.

[0043] Adsorption assembly 12; Adsorption chamber 121; Waste gas inlet 1211; Waste gas outlet 1212; Flow guide baffle 1213; Second valve 122; First port 1221; Second port 1222; Third port 1223;

[0044] Track 13; Moving part 14; Exhaust assembly 15; Exhaust pipe 151; Exhaust detection point 1511; Exhaust fan 152;

[0045] 2. Transport device; 3. Storage device; 31. Storage compartment; 32. Air outlet;

[0046] Circulating fluidized bed boiler 4; feeding assembly 41; feeding hopper 42; furnace body 43; combustion chamber 431; primary air inlet 432; secondary air inlet 433; flue gas outlet 434; return material inlet 435; primary air distribution plate 436; separator 44; tail flue 45; return material fan 46; primary air fan 47; secondary air fan 48; secondary air inlet duct 49. Detailed Implementation

[0047] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0048] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0049] The integrated adsorption and combustion system based on circulating fluidized bed in this invention includes an adsorption device 1, a transport device 2, a storage device 3, and a circulating fluidized bed boiler 4.

[0050] The adsorption device 1 includes an air intake assembly 11 and an adsorption assembly 12. The air intake assembly 11 is used to introduce VOCs into the adsorption assembly 12. There are multiple adsorption assemblies 12, which are connected in sequence and adjacent adsorption assemblies 12 are detachably connected. The adsorption assembly 12 has an adsorption chamber 121, which is filled with an adsorbent for purifying VOCs.

[0051] The transport device 2 is used to transport the adsorbent in the adsorption assembly 12 to the storage device 3.

[0052] Storage device 3 provides adsorbent to circulating fluidized bed boiler 4 as fuel for circulating fluidized bed boiler 4.

[0053] For example, such as Figure 1-3 As shown, multiple adsorption components 12 are connected in series from beginning to end. VOCs enter from the air intake component 11 and then pass through multiple adsorption chambers 121 in sequence. After the VOCs are adsorbed by the adsorbent, the exhaust gas is purified.

[0054] Optionally, the transport device 2 can be a tractor, trailer, or the like.

[0055] When the adsorbent in the adsorption component 12 reaches saturation, the saturated adsorbent is transported to the storage device 3 by the transport device 2 for storage. When the circulating fluidized bed boiler 4 needs fuel, the adsorbent in the storage device 3 is transported to the circulating fluidized bed boiler 4 as fuel.

[0056] In related technologies, fluidized beds are used to achieve continuous adsorption-desorption operations to eliminate VOCs. However, fluidized bed systems have complex structures, and activated carbon, used as the adsorbent, is expensive, making it difficult for fluidized bed components to handle large volumes of organic waste gas. Moreover, activated carbon needs to be recycled, and its adsorption effect deteriorates after prolonged use. Activated carbon is also flammable and easily combusts during recycling, resulting in low safety.

[0057] The circulating fluidized bed-based integrated adsorption and combustion system of this invention utilizes semi-coke as an adsorbent. Firstly, semi-coke possesses excellent properties such as high fixed carbon content, high chemical activity, low ash content, low sulfur content, and low phosphorus content, making it a potential adsorbent. Furthermore, semi-coke is an industrial by-product, widely available and inexpensive, thus reducing the cost of the circulating fluidized bed-based integrated adsorption and combustion system of this invention. The circulating fluidized bed boiler 4 has advantages such as wide fuel adaptability, strong load regulation capability, and low pollutant emission control costs. It can directly burn semi-coke particles without pretreatment, and the technology is mature and reliable.

[0058] Secondly, the integrated adsorption and combustion system based on circulating fluidized bed in this invention uses semi-coke directly as an adsorbent. After one adsorption saturation, it is used as fuel for the circulating fluidized bed boiler 4, thus eliminating the need for adsorption-desorption cycles. This not only simplifies the structure of the circulating fluidized bed boiler 4 and makes operation simple, but also eliminates the need for adsorbent recycling, resulting in higher safety performance. Therefore, it can handle large quantities of VOCs. This invention achieves efficient removal and calorific value recovery of atmospheric pollutants (VOCs) and directly promotes the large-scale and resource-based utilization of industrial by-product semi-coke, realizing a win-win situation for energy and environmental protection.

[0059] The integrated adsorption and combustion system based on circulating fluidized bed in this invention is particularly suitable for large industrial parks. Distributed adsorption devices 1 can be installed in factories with VOCs treatment needs to centrally transport and store nearly saturated semi-coke particles and send them to the park's own circulating fluidized bed boiler 4 for combustion. The circulating fluidized bed boiler 4 generates heat or electricity for the park's use, thereby realizing large-scale centralized treatment of VOCs and efficient and clean utilization of low-grade resources.

[0060] Therefore, the integrated adsorption and combustion system based on a circulating fluidized bed in this invention has the advantages of low cost, simple structure, and high efficiency in treating VOCs.

[0061] In some embodiments, the adsorption device 1 further includes a track 13 and a moving member 14. There are multiple moving members 14, and each moving member 14 corresponds to and is connected to a multiple adsorption component 12. The moving member 14 cooperates with the track 13 and can drive the adsorption component 12 to move along the track 13.

[0062] The track 13 extends along the direction of the track and is provided with a first station, a second station to the (n+1)th station, and each station can accommodate an adsorption component 12.

[0063] For example, such as Figure 2 As shown, each adsorption assembly 12 is provided with a movable component 14 below it. The adsorption assembly 12 is detachably connected to the movable component 14. The movable component 14 is provided with multiple wheels, which can cooperate with the track 13 and move along the track 13. When the adsorbent in the adsorption chamber 121 is saturated, the movable component 14 can be detached from the track 13. The movable component 14 can be connected to a trailer or tractor, so that the adsorption assembly 12 can move between the track 13 and the storage device 3, thereby transporting the adsorbent to the storage device 3.

[0064] like Figure 2 As shown, the track extends in the same direction as the front and back. An air intake assembly 11 is provided at the front end of the track 13, which can be used to transport VOCs to the adsorption chamber 121. An exhaust assembly 15 can be used to discharge the purified VOCs from the adsorption device 1. An exhaust assembly 15 is provided at the rear end of the track 13. The track 13 has multiple workstations, including a first workstation, a second workstation, ..., an nth workstation, and an (n+1)th workstation arranged sequentially from front to back. The air intake assembly 11 is located at the first workstation, and the exhaust assembly 15 is located at the nth workstation or the (n+1)th workstation.

[0065] It should be noted that n≥3, which takes into account that when the adsorbent in the adsorption chamber 121 of the first station is saturated, VOCs can still pass through at least two adsorption chambers 121 to meet the purification requirements. In actual operation, the number of adsorption chambers 121 can be flexibly increased or decreased according to the concentration, air volume, type of VOCs to be treated, and the performance of the adsorbent, so as to minimize costs while ensuring that the exhaust gas meets emission standards.

[0066] Optionally, n can be 3-100. For example, when the concentration of VOCs is low, the number of n is small, such as 3, 4, 5, 6, 10, etc. When the concentration of VOCs is high, the number of n is large, such as 15, 18, 25, etc.

[0067] The integrated adsorption and combustion system based on a circulating fluidized bed in this invention, through the inclusion of a moving component 14 and a track 13, allows the adsorption assembly 12 to move between the track 13 and the storage device 3, thereby delivering saturated adsorbent to the storage device 3. Furthermore, the adsorption device 1 employs a series fixed-bed adsorption mode, allowing the number of adsorption assemblies 12 to be increased or decreased according to actual needs, meeting the treatment requirements of different air volumes and VOC concentrations. It is particularly suitable for purifying large-volume, low-concentration waste gases, and has a wide range of applications.

[0068] In some embodiments, such as Figure 2 As shown, the air intake assembly 11 is located at the first work station. The air intake assembly 11 has an air intake pipe 111, a first branch 112 and a second branch 113. One end of the first branch 112 and one end of the second branch 113 can be connected to the air intake pipe 111, and the other end of the first branch 112 and the other end of the second branch 113 can be connected to the adsorption chamber 121.

[0069] For example, such as Figure 2 As shown, the intake assembly 11 also includes a first valve 114. One end of the intake pipe 111 is for VOCs to enter, and the other end of the intake pipe 111 is connected to one end of the first branch 112 and one end of the second branch 113 through the first valve 114. The first valve 114 is a three-way valve.

[0070] The adsorption chamber 121 is provided with an exhaust gas inlet 1211 and an exhaust gas outlet 1212, wherein the exhaust gas inlet 1211 is positioned higher than the exhaust gas outlet 1212, and the exhaust gas inlet 1211 and exhaust gas outlet 1212 are respectively located on both sides of the adsorption chamber 121. During operation, in two adjacent workstations, the exhaust gas outlet 1212 of the adsorption chamber 121 at the previous workstation is detachably connected to the exhaust gas inlet 1211 of the adsorption chamber 121 at the next workstation.

[0071] The first branch 112 is detachably connected to the exhaust gas inlet 1211 of the adsorption chamber 121 on the first station, and the second branch 113 is detachably connected to the exhaust gas inlet 1211 of the adsorption chamber 121 on the second station.

[0072] It should be noted that when the adsorption component 12 moves from the track 13 to the storage device 3, both the exhaust gas inlet 1211 and the exhaust gas outlet 1212 of the adsorption component 12 are closed, thereby preventing the gas in the adsorption chamber 121 from flowing out.

[0073] Optionally, a flow guide baffle 1213 may be installed inside the adsorption chamber 121, such as... Figure 3 As shown, the space between the flow guide baffles 1213 is filled with adsorbent. VOCs flow along the chambers and paths divided by the baffles. This design increases the residence time of VOCs in the chamber and reduces the flow dead zone inside the adsorption chamber 121, thereby improving the utilization rate of the adsorbent.

[0074] It should be noted that, Figure 1 The intake assembly 11 in the diagram is shown below. Figure 2 This is a detailed structural diagram of the intake assembly 11.

[0075] In some embodiments, the adsorption device 1 has a first state and a second state. In the first state, the second branch 113 is disconnected from the air inlet pipe 111, and the air inlet pipe 111 is connected to the adsorption chamber 121 at the first station through the first branch 112. The adsorption chambers 121 at the first station to the nth station are connected sequentially.

[0076] In the second state, the adsorption component 12 on the first station is detached from the first station, the first branch 112 is disconnected from the air inlet pipe 111, the air inlet pipe 111 is connected to the adsorption chamber 121 on the second station through the second branch 113, and the adsorption chambers 121 on the second station to the nth station are connected sequentially.

[0077] For example, such as Figure 2 As shown, in the first state, the adsorption device 1 has an adsorption component 12 on each of the first to nth stations, and the adsorption chambers 121 on all stations are connected in sequence. The air inlet pipe 111 is connected to the first branch 112, and VOCs pass through the adsorption chambers 121 on the first to nth stations in sequence.

[0078] Since the first station is closest to the air inlet pipe 111, the concentration of VOCs in the adsorption chamber 121 of the first station is the highest. Therefore, the adsorbent in the first station reaches adsorption saturation first.

[0079] In the second state, when the adsorption device 1 is in the first station, the adsorbent in the first station reaches adsorption saturation. The adsorption assembly 12 in the first station is then disassembled, and the adsorbent in the adsorption assembly 12 is sent to the storage device 3 by the transport device 2. At this time, the air intake pipe 111 is connected to the second branch 113, and VOCs pass through the second station to the adsorption chamber 121 in the nth station in sequence.

[0080] In some embodiments, the adsorption device 1 also has a third state and a fourth state.

[0081] In the third state, the adsorbent in the adsorption component 12 at the first station is replaced, the adsorption component 12 at the first station is moved to the (n+1)th station, and the adsorption chamber 121 at the (n+1)th station is connected to the adsorption chamber 121 at the nth station.

[0082] In the fourth state, the adsorption components 12 on the second station to the (n+1)th station are all moved forward one station, the second branch 113 is disconnected from the air inlet pipe 111, the air inlet pipe 111 is connected to the adsorption chamber 121 on the first station through the first branch 112, and the adsorption chambers 121 on the first station to the nth station are connected in sequence.

[0083] In the third state, the adsorption device 1 fills the adsorption component 12 at the first station with new adsorbent, then moves the adsorption component 12 to the (n+1)th station, and then connects the exhaust gas inlet 1211 of the adsorption component 12 to the exhaust gas outlet 1212 of the adsorption component 12 at the nth station.

[0084] Next, in the fourth state, the adsorption device 1 moves all the adsorption components 12 from the second station to the (n+1)th station forward by one station, that is, the adsorption device 1 returns to the first state.

[0085] The adsorption device 1 of the integrated adsorption and combustion system based on a circulating fluidized bed in this invention adopts a modular design for each adsorption component 12, which can be manufactured in a standardized manner and mass-produced, facilitating large-scale promotion and application and reducing design and manufacturing costs. Moreover, multiple adsorption components 12 sequentially enter the first station, and the adsorbent in the adsorption components 12 at the first station is sequentially transported to the storage device 3, so that the adsorption process can be carried out continuously, conveniently and quickly, and thus can handle a large amount of VOCs.

[0086] In some embodiments, the adsorption device 1 further includes an exhaust assembly 15, which includes an exhaust pipe 151 and an exhaust fan 152. One end of the exhaust pipe 151 is connected to the adsorption chamber 121 at the nth or n+1th station, and the other end of the exhaust pipe 151 is connected to the exhaust fan 152, which is used to discharge the purified gas.

[0087] For example, such as Figure 2 As shown, one end of the exhaust pipe 151 is always connected to the exhaust gas outlet 1212 of the adsorption chamber 121 at the last station, and the other end of the exhaust pipe 151 is connected to the induced draft fan 152. Thus, after passing through multiple adsorption components 12, the VOCs are discharged into the atmosphere by the induced draft fan 152.

[0088] Optionally, an exhaust detection point 1511 is provided on the exhaust pipe 151. The exhaust detection point 1511 is connected to a gas analyzer to detect the concentration of VOCs in the purified gas.

[0089] The adsorption and transport process of the adsorbent is described below based on the above embodiments.

[0090] For example, there are five adsorption components 12. In the first state, the five adsorption components 12 are respectively located at the first to fifth positions. The first branch 112 of the air intake component 11 is connected to the adsorption chamber 121 at the first position. The five adsorption chambers 121 are connected in sequence, and the exhaust pipe 151 is connected to the exhaust gas outlet 1212 at the fifth position. After entering from the air intake component 11, VOCs pass through the five adsorption chambers 121 in sequence and are finally discharged from the induced draft fan 152.

[0091] When the adsorption device 1 is in the second state, the adsorbent at the first station is saturated, and the adsorption component 12 at the first station is disassembled. At this time, the adsorption components 12 at the second to fifth stations are still running, and the adsorbent at the first station is transported to the storage device 3.

[0092] When the adsorption device 1 is in the third state, the adsorption chamber 121 at the first station is refilled with new adsorbent, the adsorption assembly 12 at the first station is moved to the sixth station, the exhaust pipe 151 is disconnected from the exhaust gas outlet 1212 at the fifth station, and then the exhaust pipe 151 is connected to the exhaust gas outlet 1212 at the sixth station.

[0093] When the adsorption device 1 is in the fourth state, all adsorption components 12 at the second to sixth stations are moved forward one station, so that the adsorption device 1 returns to the first state. This allows the adsorbent at the first station to be sequentially transported to the storage device 3, enabling the adsorption process to continue continuously.

[0094] In some embodiments, the adsorption device 1 further includes a gas analyzer (not shown). The adsorption chamber 121 is provided with a waste gas inlet 1211 and a waste gas outlet 1212. A first concentration detection point (not shown) is provided at the waste gas inlet 1211, and a second concentration detection point (not shown) is provided at the waste gas outlet 1212. Both the first concentration detection point and the second concentration detection point are connected to the gas analyzer. When the difference between the values ​​of the first concentration detection point and the second concentration detection point is less than 20%, it indicates that the adsorbent in the adsorption chamber 121 has reached adsorption saturation.

[0095] The gas analyzer is connected to the first and second concentration detection points at the first station. Thus, the gas analyzer can be used to detect whether the adsorbent at the first station has reached adsorption saturation.

[0096] In other embodiments, such as Figure 3 As shown, the adsorption assembly 12 also includes a second valve 122, which is fixed on the exhaust gas inlet 1211 of the adsorption chamber 121. The second valve 122 includes a first port 1221, a second port 1222, and a third port 1223. The first port 1221 is connected to the exhaust gas inlet 1211 of the adsorption chamber 121, the second port 1222 can be connected to the first branch 112 or the second branch 113, and the third port 1223 can be connected to the exhaust gas outlet 1212 of the adsorption chamber 121 at the front station.

[0097] For example, such as Figure 2 As shown, at the first station, the second port 1222 of the second valve 122 of the adsorption assembly 12 can be connected to the first branch 112, and at the second station, the second port 1222 of the second valve 122 of the adsorption assembly 12 can be connected to the second branch 113.

[0098] In the first state, the adsorption device 1 connects the first port 1221 of the second valve 122 of the adsorption assembly 12 at the first station to the second port 1222, thus connecting the adsorption chamber 121 at the first station to the first branch 112. Simultaneously, the first port 1221 of the second valve 122 of the adsorption assembly 12 at the second station connects to the third port 1223, thus connecting two adjacent adsorption chambers 121. Subsequently, the first port 1221 of the second valve 122 at all stations connects to the third port 1223, thus connecting all adsorption chambers 121.

[0099] When the adsorption device 1 is in the second or third state, there is no adsorption component 12 at the first station. At this time, the second port 1222 of the second valve 122 of the adsorption component 12 at the second station is connected to the first port 1221, so that the second branch 113 is connected to the adsorption chamber 121 at the second station.

[0100] When the adsorption device 1 switches from the third state to the fourth state, the second port 1222 of the second valve 122 of the adsorption assembly 12 at the second station is disconnected from the second branch 113. Then, all the adsorption assemblies 12 are moved forward one station. Next, the second port 1222 of the second valve 122 at the first station is connected to the first branch 112, and the second port 1222 of the second valve 122 at the first station is connected to the first port 1221. The third port 1223 of the second valve 122 at the second station is connected to the exhaust gas outlet 1212 at the first station. The first port 1221 and the third port 1223 of the second valve 122 at the second station are connected, so that the adsorption chambers 121 at the second station and the first station are connected. Then, the first port 1221 and the third port 1223 of the second valve 122 at all subsequent stations are connected, so that all the adsorption chambers 121 are connected.

[0101] In some embodiments, such as Figure 1 As shown, the circulating fluidized bed boiler 4 is equipped with a secondary air inlet 433, and the storage device 3 includes a storage chamber 31 with an air outlet 32 ​​connected to the secondary air inlet 433. This allows the gas in the storage device 3 to be introduced into the circulating fluidized bed boiler 4, thus preventing the gas in the storage device 3 from polluting the air.

[0102] The integrated adsorption and combustion method based on a circulating fluidized bed according to embodiments of the present invention includes:

[0103] VOCs are purified using the adsorbent in adsorption device 1. The adsorbent is semi-coke.

[0104] When the adsorbent at the first station is saturated, it is transferred to the storage device 3. When the difference between the values ​​at the first concentration detection point and the second concentration detection point is less than 20%, it indicates that the adsorbent in the adsorption chamber 121 has reached adsorption saturation.

[0105] Replace the adsorbent in the adsorption component 12 at the first station, and move the adsorption component 12 at the first station to the (n+1)th station.

[0106] Move the adsorption component 12 from the second station to the (n+1)th station forward one station and repeat the above steps.

[0107] The adsorbent in storage device 3 is transported to circulating fluidized bed boiler 4 as fuel.

[0108] The integrated adsorption and combustion method based on circulating fluidized bed in this invention uses semi-coke as an adsorbent. First, semi-coke has excellent properties such as high fixed carbon content, high chemical activity, low ash content, low sulfur content, and low phosphorus content, and has the potential to act as an adsorbent. Moreover, semi-coke is an industrial by-product, which is widely available and inexpensive, thereby reducing the cost of the integrated adsorption and combustion method based on circulating fluidized bed in this invention.

[0109] Secondly, the integrated adsorption and combustion method based on circulating fluidized bed in this embodiment of the invention uses semi-coke directly as an adsorbent. After one adsorption saturation, it is used as fuel for the circulating fluidized bed boiler 4, thus eliminating the need for adsorption-desorption cycles. This not only simplifies the structure of the circulating fluidized bed boiler 4 and makes operation simple, but also eliminates the need for adsorbent recycling, resulting in higher safety performance and enabling the treatment of large quantities of VOCs.

[0110] In some embodiments, such as Figure 1 As shown, the circulating fluidized bed boiler 4 includes a furnace body 43, a feed hopper 42, a feeding assembly 41, and a separator 44. The furnace body 43 has a combustion chamber 431, and the furnace body 43 is provided with a primary air inlet 432, a secondary air inlet 433, a flue gas outlet 434, and a return material inlet 435.

[0111] The feeding hopper 42 is connected to the furnace body 43 and communicates with the combustion chamber 431.

[0112] The feeding assembly 41 is used to transport the adsorbent in the storage device 3 to the feeding hopper 42. It should be noted that the feeding assembly 41 is equipped with a sealed conveyor belt. One end of the feeding assembly 41 is sealed to the storage device 3, and the other end of the feeding assembly 41 is sealed to the feeding hopper 42, thereby ensuring that there is no VOC leakage during the feeding process.

[0113] One end of the separator 44 is connected to the flue gas outlet 434, and the other end of the separator 44 is connected to the return port 435.

[0114] The adsorbent is semi-coke, with a particle size of 2mm-6mm and a median diameter of ≤3.5mm. This particle size range falls within the market range for semi-coke coke surface particle size, eliminating the need for further crushing and reducing overall operating costs. Smaller adsorbent particles have a larger adsorption surface area; simultaneously, this particle size falls within the range of conventional circulating fluidized bed boiler feed coal particle size (0-8mm) and market-grade semi-coke coke surface particle size (0-6mm), allowing for utilization without pretreatment such as crushing. However, excessively fine semi-coke powder is inconvenient to load and unload and easily flies out with the gas, clogging the adsorption device 1 pipeline. Therefore, in this invention, the lower limit of the semi-coke particle size is preferably 2mm.

[0115] To ensure complete combustion of VOCs adsorbed by the semi-coke, especially for aromatic compounds with high ignition points and difficult combustion, the temperature inside the furnace 43 should be slightly higher than the bed temperature of a conventional coal-fired circulating fluidized bed boiler (approximately 850°C) to reduce emissions of organic pollutants such as dioxins. However, excessively high furnace temperatures can also lead to increased NOx emissions. Preferably, the temperature inside the combustion chamber 431 is 870°C-910°C, with a bed temperature deviation of less than or equal to 20°C.

[0116] In this invention, the fluid state within the furnace body 43 of the circulating fluidized bed boiler 4 is preferably rapidly fluidized to form strong axial back-mixing of solids, thereby meeting the aforementioned temperature distribution requirements, extending the residence time of fuel particles, and helping to suppress NOx emissions. This requires a relatively high fluidizing velocity. However, considering that this invention uses fine-grained semi-coke particles and the semi-coke ash is relatively fine, ensuring a sufficient amount of circulating ash; and to extend the gas residence time to promote the complete combustion of combustible gases, the fluidizing velocity can be slightly lower than that of a conventional circulating fluidized bed boiler 4. Preferably, the fluidizing velocity within the combustion chamber 431 is 4.0 m / s to 4.5 m / s.

[0117] The oxygen content in the furnace body 43 directly affects fuel burnout and NOx emissions. If the oxygen content is too low, CO, VOCs, and other components are difficult to burn completely; if the oxygen content is too high, NOx emissions are high and flue gas heat loss is large, affecting the efficiency of the circulating fluidized bed boiler 4. Preferably, in this invention, the oxygen content of the flue gas at the outlet of the separator 44 is controlled at 3.5% to 4.5%.

[0118] Because semi-coke has small particle size and produces fine ash, in order to ensure sufficient particle bed stock and circulation volume and form rapid fluidization, a high-efficiency separator 44 is required. The separator 44 is required to cut particle size d50≤15μm and critical particle size d99≤75μm.

[0119] Taking into account both the safety fluidization in the dense phase zone (minimum primary air volume requirement) and the effect of air staging on NOx emissions (limiting the proportion of primary air), preferably, the airflow entering the combustion chamber 431 from the primary air inlet 432 accounts for 40%-70% of the total airflow entering the combustion chamber 431 from the primary air inlet 432 and the secondary air inlet 433.

[0120] Optionally, the furnace body 43 is also equipped with an in-furnace flue gas denitrification device (not shown in the figure), with the denitrification agent nozzle arranged on the inlet flue of the separator 44. The denitrification agent is a urea or ammonia solution, with an ammonia-to-nitrogen ratio of 1.5 to 2.0.

[0121] If the concentration of nitrogen components in the organic waste gas is high, considering that a large amount of NOx will be generated during the combustion process of semi-coke in the circulating fluidized bed boiler 4 after adsorption, the furnace body 43 of this embodiment is also equipped with an in-furnace flue gas denitrification device (not shown in the figure), and the denitrification agent nozzle is arranged on the inlet flue of the separator 44. Preferably, the denitrification agent is urea or ammonia solution, and the ammonia-nitrogen ratio is 1.5-2.0 to ensure denitrification efficiency.

[0122] The integrated adsorption and combustion method based on circulating fluidized bed in this invention fully oxidizes and decomposes the VOCs gas components adsorbed by the semi-coke particles in the high-temperature environment inside the furnace. At the same time, the operating parameters of the circulating fluidized bed boiler 4 are controlled within the range of this invention and combined with the flue gas desulfurization and denitrification measures, so that the emissions of air pollutants such as NOx, SO2, and dioxins can be controlled below the standards, truly achieving complete elimination of VOCs.

[0123] Optionally, the furnace body 43 is provided with a primary air distribution plate 436, and the circulating fluidized bed boiler 4 also includes a tail flue 45, a return fan 46, a primary air fan 47, a secondary air fan 48, and a secondary air inlet pipe 49. The secondary air inlet 433 can be arranged in a single layer or a double layer. The secondary air fan 48 is connected to the secondary air inlet pipe 49, that is, connected to the air outlet 32 ​​of the storage device 3.

[0124] If the concentration of sulfur components in the organic waste gas is high, considering that a large amount of SO2 will be generated during the combustion process of semi-coke in the circulating fluidized bed boiler 4 after adsorption, and considering that the circulating fluidized bed boiler 4 of this invention is also equipped with a limestone feeding device for in-furnace flue gas desulfurization, the limestone feeding port is located on the front wall of the circulating fluidized bed boiler 4, higher than the dense phase zone. Preferably, the limestone particle size range is 0-200μm, and the median diameter is less than or equal to 30μm, in order to achieve the optimal in-furnace desulfurization effect.

[0125] To ensure the complete combustion of combustible gases, especially atmospheric pollutants such as dioxins, at the furnace outlet, the circulating fluidized bed boiler 4 of this embodiment of the invention is also provided with a burnout air supply at the top of the furnace body 43. The burnout air nozzle is located on the front wall of the circulating fluidized bed boiler 4, arranged in a single layer on one side, and is lower than the lower edge of the horizontal flue at the furnace outlet. This allows for better utilization of the swirling flow and good gas mixing within the separator 44, thereby promoting the complete combustion of combustible gases.

[0126] The integrated adsorption and combustion method based on circulating fluidized bed in this invention is particularly suitable for large industrial parks. Distributed adsorption devices 1 can be set up for factories with VOCs treatment needs to centrally transport and store nearly saturated semi-coke particles and send them to the park's own circulating fluidized bed boiler 4 for combustion. The circulating fluidized bed boiler 4 generates heat or electricity for the park's use, thereby realizing large-scale centralized treatment of VOCs and efficient and clean utilization of low-grade resources.

[0127] The following describes a specific embodiment of the integrated adsorption and combustion method based on a circulating fluidized bed according to the present invention.

[0128] In a certain industrial park, there are 20 emissions of pollutants, including dimethylformamide, benzene, toluene, xylene, non-methane hydrocarbons, hydrogen sulfide, ozone, particulate matter, ammonia, propylene oxide, propionaldehyde, dimethylformamide, fumes, nitrogen oxides, sulfur dioxide, dust, odor, methanol, chlorine, and methane. These pollutants involve 21 companies in industries such as chemical, pharmaceutical, textile, building materials, food, and wastewater treatment. The average VOCs concentration in the waste gas to be treated is 15.4 mg / m3, and the instantaneous total treatment volume exceeds 2.6 million cubic meters per hour.

[0129] according to Figure 1 The system shown involves the construction of adsorption devices 1 at several locations within the industrial park, employing 3-5 stage adsorption components 12 to treat organic waste gas from adjacent factories. The VOCs concentration in the purified tail gas is less than 10 mg / m³. The adsorbent is selected from screened semi-coke particles (2mm-6mm), costing 600-700 yuan / ton. It is estimated that nearly 1,000 tons of high-calorific-value organic matter can be adsorbed annually by the semi-coke. These saturated semi-coke particles are directly used as fuel, uniformly fed into the circulating fluidized bed boiler 4 within the industrial park for combustion. By recovering the combustion heat of VOCs, over 1,400 tons of standard coal can be saved annually, resulting in significant economic benefits.

[0130] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0131] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0132] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0133] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0134] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0135] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. An integrated adsorption and combustion system based on a circulating fluidized bed, characterized in that, include: An adsorption device includes an air inlet assembly, an adsorption assembly, a track, and moving parts. The air inlet assembly is used to introduce VOCs into the adsorption assembly. Multiple adsorption assemblies are connected sequentially, with adjacent assemblies detachably connected. Each adsorption assembly has an adsorption chamber filled with an adsorbent for purifying VOCs. Multiple moving parts are connected to and correspond one-to-one with each adsorption assembly. Each moving part cooperates with the track and can move the adsorption assembly along the track. A first station, a second station, and up to the (n+1)th station are sequentially provided along the extension direction of the track, each station accommodating one adsorption assembly. The air inlet assembly is located at the first station and has an air inlet pipe, a first branch, and a second branch. One end of the first branch and one end of the second branch are connected to the air inlet pipe, and the other ends of the first branch and the second branch are connected to the adsorption chamber. A transport device and a storage device, wherein the transport device is used to transport the adsorbent in the adsorption assembly to the storage device; A circulating fluidized bed boiler, wherein the storage device provides the adsorbent to the circulating fluidized bed boiler as fuel for the circulating fluidized bed boiler.

2. The integrated adsorption and combustion system based on a circulating fluidized bed according to claim 1, characterized in that, The adsorption device has a first state and a second state. In the first state, the second branch is disconnected from the air inlet pipe, and the air inlet pipe is connected to the adsorption chamber at the first station through the first branch. The adsorption chambers at the first station to the nth station are connected sequentially. In the second state, the adsorption component on the first station is detached from the first station, the first branch is disconnected from the air inlet pipe, the air inlet pipe is connected to the adsorption chamber on the second station through the second branch, and the adsorption chambers on the second station to the nth station are connected sequentially.

3. The integrated adsorption and combustion system based on a circulating fluidized bed according to claim 2, characterized in that, The adsorption device also has a third state and a fourth state. In the third state, the adsorbent in the adsorption component at the first station is replaced, the adsorption component at the first station is moved to the (n+1)th station, and the adsorption chamber at the (n+1)th station is connected to the adsorption chamber at the nth station. In the fourth state, the adsorption components at the second station to the (n+1)th station are all moved forward one station, the second branch is disconnected from the air inlet pipe, the air inlet pipe is connected to the adsorption chamber at the first station through the first branch, and the adsorption chambers at the first station to the nth station are connected sequentially.

4. The integrated adsorption and combustion system based on a circulating fluidized bed according to claim 3, characterized in that, The adsorption device further includes an exhaust assembly, which includes an exhaust pipe and an induced draft fan. One end of the exhaust pipe is connected to the adsorption chamber at the nth or n+1th workstation, and the other end of the exhaust pipe is connected to the induced draft fan, which is used to discharge the purified gas.

5. The integrated adsorption and combustion system based on a circulating fluidized bed according to claim 4, characterized in that, The adsorption device also includes a gas analyzer. The adsorption chamber is provided with a waste gas inlet and a waste gas outlet. A first concentration detection point is provided at the waste gas inlet, and a second concentration detection point is provided at the waste gas outlet. Both the first concentration detection point and the second concentration detection point are connected to the gas analyzer. When the difference between the values ​​of the first concentration detection point and the second concentration detection point is less than 20%, it indicates that the adsorbent in the adsorption chamber has reached adsorption saturation.

6. The integrated adsorption and combustion system based on a circulating fluidized bed according to any one of claims 1-5, characterized in that, The circulating fluidized bed boiler is provided with a secondary air inlet, and the storage device includes a storage chamber with an air outlet connected to the secondary air inlet.

7. A circulating fluidized bed-based adsorption-combustion integrated method, wherein the method utilizes the circulating fluidized bed-based adsorption-combustion integrated system according to any one of claims 1-6, characterized in that, include: VOCs are purified using the adsorbent in the adsorption device. When the adsorbent at the first station is saturated, the adsorbent at the first station is transported to the storage device; Replace the adsorbent in the adsorption component at the first station, and move the adsorption component at the first station to the (n+1)th station; Move the adsorption components from the second station to the (n+1)th station forward one station, and repeat the above steps; The adsorbent in the storage device is transported to the circulating fluidized bed boiler as fuel.

8. The integrated adsorption and combustion method based on a circulating fluidized bed according to claim 7, characterized in that, The circulating fluidized bed boiler includes: The furnace body has a combustion chamber and is provided with a primary air inlet, a secondary air inlet, a flue gas outlet, and a return material outlet. A feeding hopper, which is connected to the furnace body and communicates with the combustion chamber; A feeding assembly for conveying the adsorbent in the storage device to the feeding hopper; A separator, one end of which is connected to the flue gas outlet and the other end of which is connected to the return port; The adsorbent is semi-coke, the particle size of which is 2mm-6mm and the median diameter of which is less than or equal to 3.5mm. The temperature inside the combustion chamber is 870℃-910℃, with a bed temperature deviation of less than or equal to 20℃, and the fluidization velocity inside the combustion chamber is 4.0 m / s-4.5 m / s; The oxygen content of the flue gas at the outlet of the separator is 3.5%-4.5%, the cutting particle size of the separator is d50≤15μm, and the critical particle size of the separator is d99≤75μm; The airflow entering the combustion chamber from the primary air inlet accounts for 40%-70% of the total airflow entering the combustion chamber from the primary air inlet and the secondary air inlet.

Images