A biomass gasification furnace and catalytic decoking component thereof

Abstract

The present invention discloses a biomass gasification furnace, comprising a furnace body provided with a gas outlet pipe, wherein a partition plate is provided in the furnace body along the circumference of the furnace body, and the partition plate and the inner wall of the furnace body form a guide channel for guiding the gas into the gas outlet pipe, the guide channel is annular and the upper end is closed, and the guide channel is connected to the gas outlet pipe, and a catalytic decoking component is provided in the guide channel. When the gas passes through the catalytic decoking component and is discharged from the gas outlet pipe, the gas is catalytically filtered to reduce the tar content, and the probability of subsequent clogging of the pipeline due to tar condensation is also reduced, thereby extending the equipment detection cycle. Specifically, the partition plate and the tar cracking catalyst both increase the resistance of the gas flowing from the furnace body to the gas outlet pipe, so that the gas stays in the sub-cavity for a longer time, and the catalytic cracking reaction time in the high-temperature section is longer and more sufficient, thereby effectively reducing the tar content in the gas.

Description

Technical Field

[0001] The invention relates to a biomass gasifier boiler, in particular to a biomass gasifier and a catalytic decoking component thereof. Background Art

[0002] Biomass fuel is a renewable resource. In terms of energy equivalent, biomass energy ranks fourth after coal, oil and natural gas.

[0003] One of the main problems with the gas produced by biomass gasification furnaces in my country at present is the high tar content in the gas, which can easily clog the pipeline during gas transportation and cause damage to subsequent combustion equipment. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the object of the present invention is to provide a biomass gasifier to reduce the probability of pipeline blockage due to high tar content in the fuel gas.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A biomass gasification furnace comprises a furnace body provided with a gas outlet pipe, wherein a partition plate is provided in the furnace body along the circumference of the furnace body, the partition plate and the inner wall of the furnace body form a guide channel for guiding the gas into the gas outlet pipe, the guide channel is annular and the upper end is closed, and the guide channel is connected to the gas outlet pipe, a catalytic decoking component is provided in the guide channel, and the gas outlet pipe is located above the catalytic decoking component, the catalytic decoking component comprises a mounting plate abutting the inner wall of the outer ring of the guide channel and a plurality of partitions fixedly connected to the mounting plate at intervals in the vertical direction, a sub-cavity is formed between the mounting plate, the partition plate and two adjacent partitions, at least one sub-cavity is filled with a tar cracking catalyst, at least one partition is provided with a first conical hole that is thin at the top and thick at the bottom, and at least one partition is provided with a second conical hole that is thick at the top and thin at the bottom.

[0007] By adopting the above technical solution, when the gas passes through the catalytic decoking component and is discharged from the gas outlet pipe, the gas is filtered, which reduces the tar content contained therein, reduces the probability of subsequent pipe blockage due to tar condensation, and extends the equipment inspection cycle. Specifically, the first conical hole can block the probability of large particles of dust entering the sub-cavity, acting as a primary filter. The second conical hole can retain large particles of dust in the sub-cavity, acting as a secondary filter, making the gas purer. At the same time, the partition and the tar cracking catalyst both increase the resistance of the gas flowing from the furnace body to the gas outlet pipe, making it stay in the sub-cavity longer, and the catalytic cracking reaction time in the high-temperature section is longer and more sufficient, effectively reducing the tar content in the gas.

[0008] The present invention is further configured such that the partitions provided with the first conical holes and the partitions provided with the second conical holes are arranged in a staggered manner.

[0009] By adopting the above technical solution, the path that the gas needs to pass through the catalytic decoking element is extended, so that it stays in the sub-cavity longer, the catalytic cracking reaction time in the high-temperature section is longer and more sufficient, and the tar content in the gas is effectively reduced.

[0010] The present invention is further configured such that the first conical holes and the second conical holes on adjacent partitions are staggered in the vertical direction.

[0011] By adopting the above technical solution, the path that the gas needs to pass through the catalytic decoking element is extended, so that it stays in the sub-cavity longer, the catalytic cracking reaction time in the high-temperature section is longer and more sufficient, and the tar content in the gas is effectively reduced.

[0012] The present invention is further configured such that the temperature of the catalytic decoking component located in the guide channel is 800-1000 degrees Celsius.

[0013] By adopting the above technical solution, it is ensured that the catalytic decoking component is located at the place where the catalytic cracking reaction efficiency is highest in the high-temperature section, so that it has a better decoking effect.

[0014] The present invention is further configured as follows: a ash cleaning door is provided on the outer wall of the furnace body, a ash cleaning port corresponding to the ash cleaning door is provided on the mounting plate corresponding to each sub-cavity, and an inner door for closing the ash cleaning port is provided on the ash cleaning port.

[0015] By adopting the above technical solution, after a period of use, the cleaning door and the inner door can be opened, and the dust in the sub-cavity can be cleaned through the cleaning port or the internal tar cracking catalyst can be replaced. In fact, the device maintains good working efficiency.

[0016] The present invention is further configured as follows: a plurality of ash cleaning doors are provided along the circumference of the outer wall of the furnace body.

[0017] By adopting the above technical solution, the interior of the sub-cavity can be maintained and cleaned more conveniently and quickly.

[0018] The present invention is further configured as follows: a purge pipe for supplying compressed gas into the furnace body is installed on the dust cleaning door.

[0019] By adopting the above technical solution, during the shutdown and fire suppression stage of the gasifier, safer gases such as compressed nitrogen can be introduced into the sub-cavity through the purge pipe, thereby completing the purge of the sub-cavity and reducing the frequency of opening the inner door for cleaning and maintenance of the sub-cavity.

[0020] The present invention is further configured as follows: two pressure transmitters for detecting pressure are provided on the furnace body, and sampling points of the two pressure transmitters are respectively located on the upper and lower sides of the catalytic decoking component.

[0021] By adopting the above technical solution, the blockage status of the catalytic decoking component is determined based on the pressure values ​​detected by the two pressure transmitters, so that the catalytic decoking component can be maintained and cleaned in a timely manner to prevent the operation of the gasifier system from being affected by dust accumulation inside the catalytic decoking component.

[0022] The present invention is further configured as follows: the catalytic decoking component is made of heat-resistant steel or ceramics; when the catalytic decoking component is made of heat-resistant steel, the catalytic decoking component is welded and fixed to the furnace body; when the catalytic decoking component is made of ceramics, a placement rack for placing the catalytic decoking component is fixedly provided in the furnace body.

[0023] By adopting the above technical solution, the device is applicable to catalytic decoking components made of various materials, that is, catalytic decoking components made of different materials can be selected according to specific conditions, so that it can better adapt to various working conditions.

[0024] In view of the shortcomings of the prior art, the present invention aims to provide a catalytic decoking mechanism that can reduce the tar content in fuel gas.

[0025] To achieve the above object, the present invention provides the following technical solutions:

[0026] A catalytic decoking mechanism comprises a catalytic decoking component.

[0027] The present invention has the following advantages: 1. It reduces the amount of tar contained in the fuel gas, reduces the probability of subsequent tar condensation and clogging of the pipeline, and reduces the number of subsequent combustion equipment damages; 2. It allows for convenient cleaning and maintenance of the catalytic decoking components; 3. It allows the fuel gas to stay in the sub-chamber for a longer time and stay in the temperature range where the catalytic cracking reaction is most efficient, thereby achieving a better tar removal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic structural diagram of Example 1;

[0029] Figure 2 is a cross-sectional view of Example 1;

[0030] Figure 3 This is a schematic diagram of the structure of the catalytic decoking component in Example 1.

[0031] Figure 4 This is a schematic structural diagram of the catalytic decoking component in Example 5.

[0032] Figure numerals: 1. furnace body; 2. gas outlet pipe; 3. partition plate; 4. guide channel; 5. catalytic decoking component; 6. mounting plate; 7. partition plate; 8. sub-chamber; 9. tar cracking catalyst; 10. first conical hole; 11. second conical hole; 12. ash cleaning door; 13. ash cleaning port; 14. inner door; 15. purge pipe; 16. pressure transmitter; 17. temperature detector; 18. online sampling tube holder; 19. force handle; 20. steam nozzle; 21. nozzle. DETAILED DESCRIPTION

[0033] Example 1:

[0034] like Figure 1 and Figure 2 As shown, a biomass gasification furnace includes a furnace body 1 provided with a gas outlet pipe 2, and a plurality of gas outlet pipes 2 are provided along the circumference of the furnace body 1. A partition plate 3 is provided inside the furnace body 1 along the circumference of the furnace body 1. The partition plate 3 is arranged in an annular shape, and the lower end of the partition plate 3 is arranged with a constriction. The partition plate 3 and the inner wall of the furnace body 1 form a guide channel 4 for guiding the gas into the gas outlet pipe 2. The guide channel 4 is annular and has a closed upper end, and the guide channel 4 is connected to the gas outlet pipe 2. A catalytic decoking component 5 is provided in the guide channel 4, and the gas outlet pipe 2 is located above the catalytic decoking component 5. The temperature of the catalytic decoking component 5 located in the guide channel 4 is 800-850 degrees Celsius.

[0035] As the fuel gas passes through the catalytic decoking element 5 and is discharged from the gas outlet pipe 2, it is filtered by the element, reducing the amount of tar it contains. This reduces the likelihood of tar condensation and pipe blockage, and also reduces the likelihood of subsequent damage to combustion equipment. Furthermore, the temperature range of 800-1000°C is the most intense for catalytic cracking of tar, which enhances the catalytic decoking effect of the element 5.

[0036] Specifically, such as Figure 2 and Figure 3 As shown, the catalytic decoking element 5 includes a mounting plate 6 that abuts the inner wall of the outer ring of the diversion channel 4 and three partitions 7 fixedly connected to the mounting plate 6 at intervals in the vertical direction. A subcavity 8 is formed between the mounting plate 6, the partition plate 3, and two adjacent partitions 7. The upper subcavity 8 is filled with a tar cracking catalyst 9. The middle partition 7 has a first conical hole 10 that is narrow at the top and wide at the bottom. The top and bottom partitions 7 each have a second conical hole 11 that is wide at the top and narrow at the bottom. The first and second conical holes 10, 11 are staggered in the vertical direction.

[0037] The first conical hole 10 prevents large dust particles from entering the sub-chamber 8, providing primary filtration. The second conical hole 11 retains large dust particles within the sub-chamber 8, providing secondary filtration and purifying the gas. Simultaneously, the partition 7 and the tar cracking catalyst 9 increase the resistance of the gas flowing from the furnace body 1 to the gas outlet pipe 2, extending its residence time within the sub-chamber 8 and allowing for a longer and more complete catalytic cracking reaction in the high-temperature zone, effectively reducing the tar content in the gas.

[0038] like Figure 2 and Figure 3 As shown, the catalytic decoking element 5 is made of heat-resistant steel or ceramic. When the catalytic decoking element 5 is made of heat-resistant steel, it is welded to the furnace body 1. When the catalytic decoking element 5 is made of ceramic, a placement rack for the catalytic decoking element 5 is fixedly provided in the furnace body 1. The catalytic decoking element 5 can be directly placed on the placement rack or secured with bolts.

[0039] like Figure 2 and Figure 3 As shown, to facilitate cleaning and maintenance of the catalytic decoking unit 5, a cleaning door 12 is installed on the outer wall of the furnace body 1. The cleaning door 12 is tubular, with one end connected to the furnace body 1 and the other end sealed and secured by a flange. Four cleaning doors 12 are provided along the circumference of the furnace body 1. Each sub-chamber 8 has a corresponding cleaning port 13 on the mounting plate 6. An inner door 14 is slidably connected to the mounting plate 6 to seal the cleaning port 13. A force handle 19 is provided at the free end of the inner door 14 to facilitate application of force.

[0040] When the catalytic decoking element 5 requires cleaning and maintenance, the cleaning door 12 and inner door 14 can be opened and the cleaning and maintenance performed through the cleaning port 13. Furthermore, a purge pipe 15 is mounted on the cleaning door 12 for supplying compressed gas into the furnace body 1. During the gasifier shutdown and fire suppression phase, a safer gas, such as compressed nitrogen, can be introduced into the sub-cavity 8 through the purge pipe 15 to purge the sub-cavity 8, reducing the frequency of opening the inner door 14 for cleaning and maintenance.

[0041] like Figure 2 and Figure 3 As shown, in order to promptly determine whether the catalytic decoking unit 5 is clogged and needs cleaning, the furnace body 1 is equipped with two pressure transmitters 16 for detecting pressure. The sampling points of the two pressure transmitters 16 are located on the upper and lower sides of the catalytic decoking unit 5, respectively. The blockage of the catalytic decoking unit 5 is determined based on the pressure values ​​detected by the two pressure transmitters 16, so that the catalytic decoking unit 5 can be maintained and cleaned in a timely manner, preventing the catalytic decoking unit 5 from affecting the operation of the equipment.

[0042] To monitor and feedback the status of the material layer within furnace body 1 and the effectiveness of decoking, a temperature detector 17 and an online sampling tube holder 18 are provided within furnace body 1. The connection line of online sampling tube holder 18 is connected to an infrared gas analyzer, which allows real-time monitoring of the temperature field of bio-pyrolysis and the composition of the generated gas.

[0043] Example 2:

[0044] The difference between Example 2 and Example 1 is that the catalytic decoking element 5 is located at the guide channel 4 and the temperature is 850-900 degrees Celsius.

[0045] Example 3:

[0046] The difference between Example 3 and Example 1 is that the catalytic decoking element 5 is located at the guide channel 4 and the temperature is 900-950 degrees Celsius.

[0047] Example 4:

[0048] The difference between Example 4 and Example 1 is that the catalytic decoking element 5 is located at the guide channel 4 and the temperature is 950-1000 degrees Celsius.

[0049] Example 5:

[0050] like Figure 4 As shown, the difference between Example 5 and Example 1 is that an annular steam nozzle 20 is provided outside the mounting plate 6. The steam nozzle 20 is sleeved outside the mounting plate 6 and fixedly connected to the inner wall of the furnace body 1. A plurality of nozzles 21 are spaced apart on the steam nozzle 20. The nozzles 21 face the partition 7. The steam nozzle 20 is connected to an air supply pipe for supplying steam to the steam nozzle 20.

[0051] During operation, water vapor is sprayed through the nozzles onto the catalytic decoking components every 24 hours or during shutdowns for maintenance, with the treatment time controlled at 10-30 minutes. The water vapor regularly cleans the catalytic decoking components, removing tar from their inner walls and activating the catalyst, thereby enabling them to better remove tar from the fuel gas during operation and extending the catalyst's service life.

[0052] Comparative Example 1:

[0053] The difference between Comparative Example 1 and Example 1 is that no catalytic decoking component is provided.

[0054] Comparative Example 2:

[0055] The difference between Comparative Example 2 and Example 1 is that the catalytic decoking element 5 is located at the guide channel 4 at a temperature of 600-700 degrees Celsius.

[0056] Comparative Example 3:

[0057] The difference between Comparative Example 3 and Example 1 is that the catalytic decoking element 5 is located at the guide channel 4 at a temperature of 1200-1300 degrees Celsius.

[0058] Test 1: Decoking Rate

[0059] As test samples, Examples 1-5 were selected as test samples, and Comparative Examples 1-3 were selected as control samples 1-3.

[0060] Test method:

[0061] Three different types of biomass feedstock, ABC, were selected. Eight samples of each were prepared and divided equally into eight groups. The test materials were labeled a1-a8, b1-b8, and c1-c8. Groups a1-a5, b1-b5, and c1-c5 corresponded to test samples 1-5, while groups a6-a8, b6-b8, and c6-c8 corresponded to control samples 1-3, respectively.

[0062] The test material was placed in a gasification furnace of the appropriate age to react and generate combustion gas. After the reaction lasted for over one hour, the tar content in the exhaust gas of Examples 1-5 and Control Samples 1-3 was measured using the method for determining the tar and dust content in city gas (GB 12208-1990). The decoking rate was calculated based on the tar content in the exhaust gas and the tar content in the furnace gas. The tar content in the exhaust gas was also measured every two weeks to determine the deactivation time of the catalytic decoking element.

[0063] Group number Decoking rate Deactivation time of catalytic decoking components Group number Decoking rate Deactivation time of catalytic decoking components Group number Decoking rate Deactivation time of catalytic decoking components a1 99.83% 1 month b1 99.67% 1 month c1 99.72% 1 month a2 99.77% 1 month b2 99.79% 1 month c2 99.74% 1 month a3 99.81% 1 month b3 99.81% 1 month c3 99.79% 1 month a4 99.70% 1 month b4 99.75% 1 month c4 99.82% 1 month a5 99.79% 4 months b5 99.68% 4 months c5 99.3% 4 months a6 86.52% 1 month b6 85.33% 1 month c6 86.74% 1 month a7 97.33% 1 month b7 97.13% 1 month c7 97.47% 1 month a8 96.36% 1 month b8 96.75% 1 month c8 96.62% 1 month

[0064] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiment. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A biomass gasifier, characterized by: The invention comprises a furnace body (1) provided with a gas outlet pipe (2), a partition plate (3) is provided in the furnace body (1) along the circumference of the furnace body (1), the partition plate (3) and the inner wall of the furnace body (1) form a guide channel (4) for guiding the gas into the gas outlet pipe (2), the guide channel (4) is annular and the upper end is closed, and the guide channel (4) is connected to the gas outlet pipe (2), a catalytic decoking component (5) is provided in the guide channel (4), the gas outlet pipe (2) is located above the catalytic decoking component (5), the catalytic decoking component (5) includes a mounting plate (6) abutting the inner wall of the outer ring of the guide channel (4) and a plurality of partition plates (7) fixedly connected to the mounting plate (6) at intervals in the vertical direction, a sub-cavity (8) is formed between the mounting plate (6), the partition plate (3) and two adjacent partition plates (7), and the upper sub-cavity (8) is filled with a tar cracking catalyst (9); The partitions (7) are three pieces, a first conical hole (10) with a thin top and a thick bottom is opened on the middle partition (7), and a second conical hole (11) with a thick top and a thin bottom is opened on the top and bottom two partitions (7), and the first conical hole (10) and the second conical hole (11) are staggered in the vertical direction.

2. The biomass gasifier according to claim 1, characterized in that: The catalytic decoking element (5) is located in the guide channel (4) at a temperature of 800-1000 degrees Celsius.

3. The biomass gasifier according to claim 1, characterized in that: A ash cleaning door (12) is provided on the outer wall of the furnace body (1), and an ash cleaning port (13) corresponding to the ash cleaning door (12) is provided on the mounting plate (6) corresponding to each sub-cavity (8), and an inner door (14) for closing the ash cleaning port (13) is provided on the ash cleaning port (13).

4. The biomass gasifier according to claim 3, characterized in that: A plurality of ash cleaning doors (12) are provided along the circumference of the outer wall of the furnace body (1).

5. The biomass gasifier according to claim 3, characterized in that: The ash cleaning door (12) is provided with a purge pipe (15) for supplying compressed gas into the furnace body (1).

6. The biomass gasifier according to claim 1, characterized in that: The furnace body (1) is provided with two pressure transmitters (16) for detecting pressure, and the sampling points of the two pressure transmitters (16) are respectively located on the upper and lower sides of the catalytic decoking component (5).

7. The biomass gasifier according to claim 1, characterized in that: The catalytic decoking component (5) is made of heat-resistant steel or ceramics. When the catalytic decoking component (5) is made of heat-resistant steel, the catalytic decoking component (5) is welded and fixed to the furnace body (1); when the catalytic decoking component (5) is made of ceramics, a placement rack for placing the catalytic decoking component (5) is fixed in the furnace body (1).

8. A catalytic decoking mechanism, characterized by: It comprises the catalytic decoking element (5) as described in any one of claims 1 to 7.

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